43: Pediatric Surgery

Question 1

What is the most common solid abdominal malignancy in children?

Answer 1

Neuroblastoma

[Usually presents as an asymptomatic mass but can present with secretory diarrhea, raccoon eyes (orbital metastases), HTN, and opsomyoclonus syndrome (unsteady gate).]

[UpToDate: The term neuroblastoma is commonly used to refer to a spectrum of neuroblastic tumors (including neuroblastomas, ganglioneuroblastomas, and ganglioneuromas) that arise from primitive sympathetic ganglion cells and, like paragangliomas and pheochromocytomas, have the capacity to synthesize and secrete catecholamines.

Neuroblastomas, which account for 97% of all neuroblastic tumors, are heterogeneous, varying in terms of location, histopathologic appearance, and biologic characteristics. They are most remarkable for their broad spectrum of clinical behavior, which can range from spontaneous regression, to maturation to a benign ganglioneuroma, or aggressive disease with metastatic dissemination leading to death.

Clinical diversity correlates closely with numerous clinical and biological factors (including patient age, tumor stage and histology, and genetic and chromosomal abnormalities). For example, most infants with disseminated disease have a favorable outcome following treatment with chemotherapy and surgery, although the majority of children older than one year of age with advanced-stage disease die from progressive disease despite intensive multimodality therapy. This clinical complexity likely derives from the developmental origins of neuroblastoma, which arises due to developmental arrest of maturing components of the embryonic neural crest.

Neuroblastoma has been associated with central hypoventilation, Hirschsprung disease, and neurofibromatosis type 1 (neurocristopathy syndrome), and as a familial disorder associated with mutations in the ALK gene.]

Question 2

What does an increase in alkaline phosphatase indicate in children?

Answer 2

Bone growth

Question 3

What is the appropriate treatment of a thyroglossal duct cyst (TGDC)?

Answer 3

Excision of the cyst, tract, and hyoid bone (at least the central portion)

[UpToDate: Infection is the most common complication of TGDC. An infected TGDC typically presents as a tender mass, with or without fever, and may have a draining sinus; it should be managed initially with antibiotics, followed by definitive surgery once the infection has resolved. The standard surgical treatment is resection of the cyst and the midportion of the hyoid bone in continuity and resection of a core of tissue from the hyoid upwards towards the foramen cecum, an operation known as the Sistrunk procedure.]

Question 4

The midgut includes which structures?

Answer 4

1. Duodenum distal to ampulla
2. Small bowel
3. Large bowel up to distal 1/3 of transverse colon

Question 5

What percent of congenital diaphragmatic hernias occur on the left side?

Answer 5

80%

[80% have associated anomalies (cardiac and neural tube defects mostly)]

[UpToDate: In most cases of CDH, herniation occurs on the left. Right-sided diaphragmatic hernias occur in approximately 15% of cases and bilateral herniation in 2%. Although there is no difference in mortality between left- and right-sided lesions, there may be a higher incidence of pulmonary complications associated with right- versus left-sided CDH.]

Question 6

How many degrees and in what direction does the midgut rotate during embryonic development?

Answer 6

270 degrees counterclockwise

Question 7

What is the appropriate treatment of pyloric stenosis?

Answer 7

Pyloromyotomy

[RUQ incision; proximal extent should be the circular muscles of stomach.]

[UpToDate: The classical operation for IHPS is Ramstedt pyloromyotomy, which involves a longitudinal incision of the hypertrophic pylorus with blunt dissection to the level of the submucosa; it relieves the constriction and allows normal passage of stomach contents into the duodenum. Laparoscopic pyloromyotomy is a minimally invasive version of the Ramstedt procedure that has been associated with a lower incidence of postoperative emesis and a shorter hospital stay, but occasionally results in incomplete pyloromyotomy. A transumbilical approach also may be used but has longer operating time.

Open and laparoscopic pyloromyotomy were compared in a prospective trial in 200 infants with ultrasonographically confirmed IHPS, who were randomly assigned to open or laparoscopic pyloromyotomy. There were no differences between groups in operating time, time to full feeding, or length of stay. However, infants in the laparoscopic group had fewer episodes of emesis (2.6 vs 1.9) and received fewer doses of analgesia (2.2 vs 1.6) than those in the open group. A similar randomized study also reported more rapid return to enteral feeding and shorter hospital stay among infants treated laparoscopically, although in 3-5% of laparoscopically performed cases the pyloromyotomy was incomplete. The study was performed at six centers with extensive experience in laparoscopic techniques.]

Question 8

What are the indications for surgery in an infant with necrotizing enterocolitis?

Answer 8

1. Free air
2. Peritonitis
3. Clinical deterioration

[UpToDate: When the diagnosis of necrotizing enterocolitis (NEC) is suspected or confirmed, a pediatric surgeon is consulted to assist the neonatology team in the evaluation and management of the infant, and to decide if and when surgery is needed. The timing of surgical intervention in a critically ill infant requires considerable judgment, as one wishes to preserve as much bowel length as possible, but an unstable patient may not be able to tolerate the surgical procedure.

Infants with NEC require surgical intervention when necrosis extends through the bowel wall and results in perforation. The decision to perform surgery is clear when pneumoperitoneum is recognized on the abdominal radiograph. However, peritonitis, extensive necrosis, or perforation can occur without evidence of free air on the radiograph. As a result, other signs that indicate peritonitis must be considered, including unremitting clinical deterioration, the presence of an abdominal mass, ascites, or intestinal obstruction.]

Question 9

What are the staging criteria for neuroblastoma?

Answer 9

• Stage 1: Localized, complete excision
• Stage 2: Incomplete excision but does not cross the midline
• Stage 3: Crosses midline +/- regional nodes
• Stage 4: Distant metastases (nodes or solid organ)
• Stage 4-S: Localized tumor with distant metastases

[NSE, LDH, HVA, Diploid tumors, and N-myc amplification (>3 copies) have a worse prognosis.]

[UpToDate:

Question 10

Which branchial cleft cyst occurs at the angle of the mandible and may connect with the external auditory canal?

Answer 10

1st branchial cleft cyst

[Often associated with the facial nerve.]

[UpToDate: First branchial cleft cysts account for less than 1 percent of branchial cleft anomalies. They typically appear on the face near the auricle. First branchial cleft cysts are further divided into types I and II. Type I first branchial cleft cysts are duplication anomalies of the external auditory canal and are of ectodermal origin. They pass through the parotid gland often in close proximity to the facial nerve. Type II branchial cleft cysts are more common and typically present below the angle of the mandible. They contain both ectoderm and mesoderm and pass through the parotid gland medial or lateral to the facial nerve and end either inferior to the external auditory canal or at the bony cartilaginous junction of the external auditory canal.]

Question 11

What is the appropriate treatment for gastroschisis?

Answer 11

1. Initially place saline-soaked gauzes and resuscitate the patient (can lose alot of fluid from the exposed bowel), TPN, NPO
2. Repair when patient is stable. Attempt to place bowel back in abdomen (may need vicryl mesh silo)
3. Primary closure at a later date if silo used

[UpToDate: Delivery room — Inflammation and fibrosis from chronic exposure to amniotic fluid result in thickening, matting of the intestines, and decreased bowel motility, and possibly luminal obstruction. Neonatal fluid losses are 2.5 times that of a healthy newborn in the first 24 hours of life. The neonate is at risk for insensible heat and fluid losses from exposure of the eviscerated bowel. In addition, third space fluid deficits from sequestration of intestinal fluid can be significant. The initial approach to management of these newborns includes:

• Wrapping the bowel with sterile saline dressings covered with plastic wrap. This preserves body heat and minimizes insensible fluid loss.
• Inserting an orogastric tube to decompress the stomach.
• Placement of peripheral intravenous access to provide fluids and broad-spectrum antibiotics that cover maternal vaginal flora (eg, ampicillin and gentamicin). The maintenance fluid requirement is increased two- to three-fold because of losses from the exposed bowel.
• Ensuring a patent airway.
• Keeping the neonate in a thermoneutral environment.

Synopsis of surgical management — In the operating room, the bowel is decompressed by aspirating stomach contents and evacuating the large bowel through the rectum. The size of the defect is increased 1 to 2 cm to minimize trauma to the bowel during reduction. The abdominal wall is manually stretched, and the bowel is replaced, taking care to avoid creating intra-abdominal pressure that is too high. Although primary closure is successful in 70% of cases, if it is unsuccessful, a staged closure with a silastic silo can be used, as in omphalocele cases. If primary closure is unlikely to be successful, a preformed silo with a spring-loaded ring can be placed at the bedside to cover the herniated intestine quickly without suturing.

Prolonged postoperative dysmotility is a common problem and interferes with enteral feeding. Studies in animal models suggest that dysmotility is due to delayed maturation of the enteric nervous system, possibly as a result of prolonged exposure to amniotic fluid.]

Question 12

How is biliary atresia diagnosed?

Answer 12

Liver biopsy (shows periportal fibrosis, bile plugging, eventual cirrhosis)

[Ultrasound and cholangiography can reveal atretic biliary tree]

[UpToDate: The diagnosis of BA is made with a series of imaging and laboratory tests and liver biopsy to exclude other causes of cholestasis. Infants should be evaluated as rapidly as possible because the success of the surgical intervention diminishes progressively with older age at surgery. Because timing is crucial, some infants (eg, those who are eight weeks or older or with a high clinical suspicion of BA) may not require each diagnostic step.

The definitive diagnosis of BA is made by a cholangiogram. This is typically performed intraoperatively; if the diagnosis of BA is confirmed, the surgeon performs a hepatoportoenterostomy (HPE, Kasai procedure).]

Question 13

What is the most common subtype of bronchopulmonary sequestration?

Answer 13

Intralobular sequestration (also known as intrapulmonary sequestration)

[UpToDate: Congenital abnormalities of the lower respiratory tract are rare, found in about 1 in 10,000 to 35,000 live births. Among these, the most common is congenital pulmonary airway malformation (CPAM), while BPS represents only 0.15 to 6.4 percent. In several reports, even tertiary care referral centers diagnose less than one case per year of BPS.

Intralobar sequestration (ILS) is overall the most common form, comprising approximately 75 to 90 percent of sequestrations, while the remainder are extralobar sequestration (ELS). The difference in prevalence of the disorders may be related to the pathogenic mechanisms, as discussed below. Males and females are equally affected with ILS, while ELS has a male predominance in most, but not all, reports. In a series of ELS cases diagnosed antenatally, the ratio of males to females was three to one. In contrast, bronchopulmonary-foregut malformation (BPFM) has a female predominance.]

Question 14

What percent of cases of Wilms tumor (nephroblastoma) are bilateral?

Answer 14

10%

[Can be differentiated from neuroblastoma on abdominal CT because it replaces renal parenchyma rather than displacing it.]

[UpToDate: Most patients have solitary Wilms tumor, 5-7% have bilateral kidney involvement, and 10% have multifocal loci within a single kidney. Tumor histology is linked to patient outcome. The classic favorable histology Wilms tumor is comprised of three cell types (blastemal, stromal, and epithelial cells). Anaplasia is associated with poor outcome.]

Question 15

Which congenital condition is characterized by a failure of cartilage to develop in the bronchus, leading to air trapping with expiration?

Answer 15

Congenital lobar emphysema (Also congenital lobar overinflation and infantile lobar emphysema)

[UpToDate: Progressive lobar hyperinflation is likely the final common pathway that results from a variety of disruptions in bronchopulmonary development. These result from abnormal interactions between embryonic endodermal and mesodermal components of the lung. Disturbances may lead to changes in the number of airways or alveoli or alveolar size. However, a definitive causative agent cannot be identified in approximately 50 percent of cases.

The most frequently identified cause of congenital lobar emphysema (CLE) is obstruction of the developing airway, which occurs in 25 percent of cases. Airway obstruction can be intrinsic or extrinsic, with the former more common. This leads to the creation of a “ball-valve” mechanism in which a greater volume of air enters the affected lobe during inspiration than leaves during expiration, producing air trapping.

Intrinsic obstruction often is caused by defects in the bronchial wall, such as deficiency of bronchial cartilage. This results in airway collapse during expiration. Intraluminal obstruction caused by meconium or mucous plugs, granulomas, or mucosal folds can cause partial obstruction of a lower airway. Extrinsic compression may be caused by vascular anomalies, such as a pulmonary artery sling or anomalous pulmonary venous return, or intrathoracic masses, such as foregut cysts and teratomas. Additionally, bronchial atresia has been identified as a common finding in CLE and other congenital cystic pulmonary malformations.

Males appear to be affected more than females, in a ratio of 3:1. The reason for the male predominance is unknown.

Congenital lobar emphysema (CLE) is characterized by overdistention of one or more lobes of the lung. This leads to compression of the remaining lung tissue and herniation of the affected lobe across the anterior mediastinum into the opposite chest, causing displacement of the mediastinum.]

Question 16

What is the appropriate treatment for a hydrocele?

Answer 16

Surgery (resect hydrocele and ligate processus vaginalis) at 1 year if not resolved or if thought to be communicating (waxing and waning in size)

[UpToDate: The most common treatment is surgical excision of the hydrocele sac. Simple aspiration is generally unsuccessful due to rapid reaccumulation of fluid. On the other hand, percutaneous aspiration of the hydrocele fluid may be successful if combined with instillation of a sclerosing agent into the sac. The potential risks of the latter approach are a low incidence of reactive orchitis/epididymitis and a higher rate of recurrence, which may then make open surgery more difficult because of the development of inflammatory adhesions between the hydrocele sac and the scrotal contents.

Hydroceles discovered in infancy are usually “communicating,” since they are associated with a patent processus vaginalis, which allows flow of peritoneal fluid into the scrotal sac. They usually disappear in the recumbent position and are often associated with herniation of abdominal contents (indirect hernia) through the processus vaginalis. Surgical repair is advised in these cases.]

Question 17

The foregut includes which structures?

Answer 17

1. Lungs
2. Esophagus
3. Stomach
4. Pancreas
5. Liver
6. Gallbladder
7. Bile duct
8. Duodenum proximal to ampulla

Question 18

What is the most common lung tumor in children?

Answer 18

Carcinoid

Question 19

What should the resuscitation strategy be in an infant with pyloric stenosis that presents with severe dehydration?

Answer 19

Normal saline boluses until making urine, then switch to D5 normal saline with 10 mEq potassium maintenance

[Avoid fluid resuscitation with K-containing fluids in children with severe dehydration as hyperkalemia can quickly develop. Avoid non-salt-containing solutions in infants, as hyponatremia can quickly develop. Infants should always have a maintenance fluid with glucose because of their limited reserves for gluconeogenesis and vulnerability for hypoglycemia.]

[UpToDate: Infants presenting with normal electrolyte values and mild dehydration, as is the case with more than 60% of patients, should receive maintenance intravenous fluids such as 5% dextrose with ¼ normal saline (0.22% NaCl) and 2 mEq KCl per 100 mL. Infants with moderate or severe dehydration require more intensive fluid management with higher NaCl concentrations (½ normal saline [0.45% NaCl] or normal saline [0.9% NaCl]) and higher rates of administration (1.5 to 2 times maintenance), perhaps combined with initial administration of a fluid bolus. In severely dehydrated infants, kidney function should be assessed prior to adding potassium to the intravenous fluids. If alkalosis is present, this should be corrected prior to surgery because it has been associated with an increased risk of post-operative apnea.]

Question 20

What is the most common overall childhood malignancy?

Answer 20

Leukemia (ALL)

[UpToDate: Acute leukemia, the most common form of cancer in children, comprises approximately 30 percent of all childhood malignancies, with acute lymphoblastic leukemia (ALL) being five times more common than acute myeloid leukemia (AML). Each year in the United States approximately 2500-3500 new cases of ALL are diagnosed in children. ALL incidence is slightly higher in Whites (36 cases/million) and Hispanics (41 cases/million) than in Black Americans (15 cases/million).

Survival rates for ALL have improved dramatically since the 1980s, with a current five-year overall survival rate estimated at greater than 85%. This improvement is in large part because of treatment of large numbers of children with sequential collaborative standardized research protocols. Approximately 75-80% of children with newly diagnosed ALL participate in clinical research trials, the goals of which are to improve clinical outcome and to minimize acute toxicities and late-occurring adverse events.]

Question 21

What is the appropriate treatment for tracheomalacia?

Answer 21

Aortopexy (aorta sutured to the back of the sternum, opens up trachea)

[Surgical indications include dying spell, failure to wean from ventilator, recurrent infections.]

[UpToDate: The long-term prognosis of this disorder is good in children with no associated problems. Most affected infants improve spontaneously by 6-12 months of age as airway caliber increases and cartilage develops. However, some remain symptomatic or have exercise intolerance as adults.

Intervention may be needed in children with life-threatening episodes of airway obstruction, recurrent infection, respiratory failure, or failure to thrive. Continuous positive airway pressure (noninvasive or invasive via tracheostomy) are the most widely used therapies, although pharmacotherapy also has been suggested. Surgical approaches such as tracheal reconstruction, placement of a tracheal stent, and surgical suspension of the trachea (tracheopexy) also have been reported. Some literature suggests potential roles for airway stents in children, though the use of airway stents typically is reserved for patients whose prognosis is otherwise grim. The development of new 3D-printed personalized external airway stents may make this approach more viable in the future. The relatively low use of stents is due to the frequency of problems related to their use. Expanding metallic stents, in particular, have been associated with a high incidence of complications and are used only in life-threatening situations. Aortopexy, the surgical suspension of the aorta from the sternum, has been reported as an effective treatment for severe tracheomalacia due to a number of different etiologies. In addition to decreasing the compression of the trachea caused by some vascular malformations, aortopexy pulls the anterior tracheal wall toward the sternum, improving airway patency.]

Question 22

How is Hirschsprung’s disease diagnosed?

Answer 22

Rectal biopsy (absence of ganglion cells in myenteric plexus)

[Occurs due to failure of neural crest cells (ganglion cells) to progress in caudad direction.]

[UpToDate: Hirschsprung disease (HD) is suspected based on clinical features described above, usually supported by contrast enema or anorectal manometry. The diagnosis is established by rectal biopsy.

A suction rectal biopsy can be done at the bedside or in an ambulatory setting without the need for general anesthesia. A biopsy should be taken 2 cm above the level of the dentate line to avoid the 1-2 cm zone of physiologic aganglionosis that is normally present. A second biopsy should be taken proximal to the first one. Adequate tissue is obtained for analysis in the majority of patients. Repeat suction biopsies or full-thickness biopsies under general anesthesia can be performed if the initial biopsy is nondiagnostic (ie, if insufficient tissue is obtained).

The diagnosis of HD is established if ganglion cells are absent in the rectal biopsy, provided that the tissue sample is adequate. Supportive findings include the presence of hypertrophic nerve fibers, elevated acetylcholinesterase activity, which can be seen with special stains, and decreased or absent calretinin-immunoreactive fibers in the lamina propria.

A normal rectal biopsy virtually excludes HD, provided that the biopsy samples are obtained from the correct site and contain at least a small amount of muscularis mucosae. Thus, a rectal suction biopsy is more sensitive and specific than contrast enema and anorectal manometry for the diagnosis of HD for children up to three years of age.]

Question 23

What is the appropriate treatment for neuroblastoma?

Answer 23

Resection (adrenal gland and kidney taken; 40% cured)

[Initially unresectable tumors may be resectable after doxorubicin-based chemo. Rarely metastasizes, but goes to lung and bone when it does.]

[UpToDate: For children with low-risk disease, surgery is the primary treatment modality when complete resection is feasible, with several exceptions.

• For patients with low-risk tumors that cannot be completely resected or which have life-threatening complications, chemotherapy and/or radiation therapy may be required.
• In the subset of patients with asymptomatic 4S disease, observation may be an option, since there is a high rate of spontaneous regression.
• For infants younger than six months of age with small, localized adrenal masses, we recommend expectant observation with serial ultrasound and urine catecholamines.

For children with intermediate-risk disease, a combined modality approach that includes chemotherapy and surgical resection is standard. The degree of surgical resection required is under investigation. The role of radiation therapy is less clear, except in the context of disease progression despite chemotherapy plus surgery or for complications such as spinal cord compression.

For children with high-risk neuroblastoma, substantial improvements have been seen with aggressive combined modality approaches. These generally include chemotherapy, surgical resection, high dose chemotherapy with stem cell rescue, radiation therapy and biologic/immunologic therapy (eg, dinutuximab). These approaches have improved event free survival, but the majority of patients eventually relapse and die of their disease.

Whenever possible, children with high-risk neuroblastoma should be enrolled in randomized controlled trials in order to validate and improve the long-term efficacy of the current treatment approach.

Children who have been treated for neuroblastoma are at risk for recurrence and for late complications of their treatment. Treating physicians should be aware of these potential issues.]

Question 24

What is the appropriate treatment for a sacrococcygeal teratoma (SCT)?

Answer 24

Coccygectomy and long-term follow up

[90% benign at birth (almost all have exophytic component). Great potential for malignancy. AFP is a good marker. 2 month mark is a huge transition: Usually benign < 2 months, usually malignant > 2 months.]

[UpToDate: For patients with mature and immature teratomas without malignant elements, we recommend complete surgical resection (Grade 1B). There does not appear to be a role for adjuvant chemotherapy following surgery.

For patients with SCTs that contain malignant elements, we recommend surgical resection, when this can be accomplished without excessive surgical morbidity, followed by adjuvant chemotherapy (Grade 1B). We suggest adjuvant chemotherapy with a platinum-based regimen such as BEP or BEJ, rather than alternative chemotherapeutic regimens (Grade 2B).

• For patients who undergo a complete resection for an SCT with malignant elements, observation, rather than adjuvant chemotherapy, may be an alternative, although there has been limited prospective evaluation of this approach.

For patients with locally advanced or metastatic malignant SCTs, we recommend neoadjuvant chemotherapy prior to resection (Grade 1B).

• For patients who are treated with either adjuvant or neoadjuvant chemotherapy, we suggest a platinum-based regimen, rather than alternative chemotherapeutic regimens (Grade 2C).]

Question 25

What classically presents with bloody stools after 1st feeding in a premature neonate?

Answer 25

Necrotizing Enterocolitis (NEC) [Risk factors include prematurity, hypoxia, and sepsis. Symptoms include lethargy, respiratory decompensation, abdominal distention, vomiting, blood per rectum. Abdominal xray may show pneumatosis intestinalis, free air, or portal vein air. Need serial lateral decubitus films to look for perforation.] [UpToDate: The majority of premature infants who develop necrotizing enterocolitis (NEC) are healthy, feeding well, and growing. A change in feeding tolerance with gastric retention is a frequent early sign. The timing of the onset of symptoms varies and appears to be inversely related to gestational age. Overall, 25% of cases present later than 30 days after birth. The median age at onset in infants with a gestational age of less than 26 weeks was 23 days, and for those with a gestational age of greater than 31 weeks, the median age at onset was 11 days. Systemic signs are nonspecific and include apnea, respiratory failure, lethargy, poor feeding, or temperature instability. Hypotension resulting from septic shock may be present in the most severe cases. Twenty to 30% of infants with NEC have associated bacteremia, which may contribute to these findings. Abdominal signs include distention, gastric retention (residual milk in the stomach before a feeding), tenderness, vomiting, diarrhea, rectal bleeding (hematochezia), and bilious drainage from enteral feeding tubes.]

Question 26

What is the most common type of esophageal atresia/tracheoesophageal fistula?

Answer 26

Type C [Proximal esophageal atresia (blind pouch) and distal tracheoesophageal fistula. Symptoms: new born spits up feeds, has excessive drooling, and respiratory symptoms with feeding; Unable to place NG tube in stomach.]

Question 27

What is the appropriate treatment for choanal atresia?

Answer 27

Surgical correction [UpToDate: Immediate management of infants with choanal atresia includes placement of an oral airway and initiation of gavage feedings. Definitive repair involves transnasal puncture and stenting or endoscopic resection of the posterior nasal septum through a transnasal approach with or without stenting. The transnasal puncture has fallen out of favor because of an unacceptable rate of recurrence. Advantages of the transnasal endoscopic approach include clear vision of the operative field and accurate removal of the atretic plate and posterior vomerine bone without damage to surrounding structures. The classic transpalatal approach is reserved for difficult or recurrent cases. Recurrent stenosis may occur even after successful surgery.]

Question 28

What causes congenital umbilical hernia to occur?

Answer 28

Failure of closure of the linea alba [Most close by age 3. Incarceration is rare. Increased occurence in African Americans and premature infants.] [UpToDate: The fascial opening (umbilical ring) exists to allow passage of the umbilical vessels from the mother into the fetus. After birth, this fascial opening closes spontaneously with continued growth of the rectus abdominis muscles toward one another. Ultimately, complete closure occurs with fusion of the peritoneal and fascial layers within a small fibrous area of the umbilicus. Closure of the umbilical ring is complete in almost all children by five years of age, but may be slower in black children. Although closure is complete in almost all children by five years of age, closure can continue in older children as manifested by lower rates of umbilical hernia. This was illustrated in a cross-sectional study of 665 black children between 4 and 11 years of age that demonstrated the following rates of umbilical hernia based upon age. Spontaneous closure is less likely to occur in patients who have an opening that is greater than 1.5 cm, a significant amount of protruding skin, are older, or have an underlying predisposing condition. Umbilical hernias are frequently seen in patients with Ehlers-Danlos, Beckwith-Wiedemann syndrome, Down syndrome, mucopolysaccharidoses, hypothyroidism, or trisomy 18. Increased intraabdominal pressure from ascites or peritoneal dialysis also can prevent closure of the umbilical ring, resulting in herniation.]

Question 29

What is the most common cause of painful lower GI bleeding in children?

Answer 29

Benign anorectal lesions (i.e. fissures) [UpToDate: The likely causes of lower gastrointestinal bleeding (LGIB) vary depending upon age. In the United States, the most common causes of rectal bleeding in infants are anal fissure or cow's milk or soy protein-induced colitis. In children 12 months and older, the most common causes of rectal bleeding are infectious gastroenteritis and anal fissures. In each age group there are other disorders that are less common but important to identify because they may be life-threatening and/or require specific treatment. The spectrum of causes is different in other parts of the world. In a report from India, for example, 24 of 85 children bled from amoebic ulcers.]

Question 30

What is the appropriate treatment for congenital lobar emphysema (CLE)?

Answer 30

Lobectomy [UpToDate: Treatment of CLE in newborns with respiratory distress consists of surgical resection of the affected lobe. Conservative management is reasonable in infants and older children who have no or minimal symptoms. Some infants who are asymptomatic at birth may also develop progressive respiratory symptoms over time which may require surgical management.]

Question 31

What is the most common lead point for intussusception in children?

Answer 31

Enlarged Peyer's patches [Other common lead points are from lymphoma and Meckel's diverticulum. 15% recurrence after reduction.] [UpToDate: Approximately 75% of cases of intussusception in children are considered to be idiopathic because there is no clear disease trigger or pathological lead point. Idiopathic intussusception is most common in children between three months and five years of age. Viral infections, including enteric adenovirus, can stimulate lymphatic tissue in the intestinal tract, resulting in hypertrophy of Peyer patches in the lymphoid-rich terminal ileum, which may act as a lead point for ileocolic intussusception. Because of this putative association with lymphoid hyperplasia, treatment with glucocorticoids has been suggested to prevent recurrence. Bacterial enteritis is also associated with intussusception. In a series of 1412 cases of bacterial enteritis seen at military treatment facilities, intussusception ensued in 37 patients (comprising 12.6% of all intussusceptions seen at these facilities). This association was noted for infection with Salmonella, E. coli, Shigella, or Campylobacter. Most cases of intussusception occurred within the first month after the bacterial enteritis. A lead point is a lesion or variation in the intestine that is trapped by peristalsis and dragged into a distal segment of the intestine, causing intussusception. A Meckel diverticulum, polyp, tumor, hematoma, or vascular malformation can act as a lead point for intussusception.]

Question 32

The hindgut includes which structures?

Answer 32

Distal 1/3 of transverse colon to anal canal

Question 33

What is the appropriate treatment for necrotizing enterocolitis?

Answer 33

Resuscitation, NPO, antibiotics, TPN, and orogastric tube [Indications for operation: free air, peritonitis, clinical deterioration. Surgery consists of resecting dead bowel and bringing up an ostomy. Need barium contrast enema before taking down ostomies to rule out distal obstruction from stenosis. Mortality is 10%.] [UpToDate: The management of necrotizing enterocolitis (NEC) depends upon the severity of illness as classified by the Bell staging criteria. Medical management is appropriate in most cases. However, infants with advanced NEC and bowel perforation (stage IIIB) require surgical intervention. Care for the infant with (or suspected) NEC is provided by a multidisciplinary team, which includes surgical consultation that assists the neonatology team in the evaluation and management of the infant, and decides if and when surgery is needed. Medical management should be initiated promptly when NEC is suspected. It includes the following: * Supportive care - Supportive care includes bowel rest, gastric decompression with intermittent nasogastric suction, discontinuation of enteral intake, initiation of parenteral nutrition, correction of metabolic and hematologic abnormalities, and stabilization of the cardiac and respiratory function. * Antibiotic therapy – After obtaining appropriate specimens for culture, we recommend a course of parenteral antibiotics that cover a broad range of aerobic and anaerobic intestinal bacteria (Grade 1C). The empiric regimen should include coverage for organisms causing late-onset sepsis, because 20-30% of infants with NEC have concomitant bacteremia. The chosen regimen should take into consideration patterns of resistance among Gram-negative enteric organisms at the individual institution. * The clinical status is monitored by laboratory studies (eg, white cell and platelet count, and serum bicarbonate and glucose measurements) and abdominal radiography to see if the patient responds to medical management, or if the NEC continues to progress and if (and when) surgical intervention is required. Surgical intervention is required either when intestinal perforation occurs or when there is unremitting clinical deterioration despite medical management suggesting extensive necrosis. We suggest primary peritoneal drainage (PPD) as the initial surgical intervention for NEC, especially in extremely low birth weight infants (birth weight \<1000 g) (Grade 2B). Response to PPD is monitored by serial abdominal examinations and radiographic studies. An alternative option is laparotomy with bowel excision. Prognosis of NEC has improved with earlier recognition and treatment, with survival rates of about 70-80% of affected infants. In addition, approximately one-half of the survivors are normal. Long-term sequelae include gastrointestinal complications (eg, short bowel syndrome, intestinal strictures, and increased frequency of bowel movements with loose stools) and impairment of growth and neurodevelopmental outcome.]

Question 34

What is Currarino syndrome? [Clinical Pearl]

Answer 34

Currarino syndrome consists of: 1. A sacral vertebral defect 2. A presacral mass (such as an anterior sacral meningocele or presacral teratoma) 3. Anorectal malformations [UpToDate: In patients with presacral teratomas, malignant transformation rarely occurs. Currarino syndrome is autosomal dominant in inheritance, localizes to 7q36, and mutations of a homeobox gene have been identified in certain families.] [Anecdote: Patient presented at birth with the sacrum angled to the left, presacral teratoma, Hirschprungs disease.]

Question 35

What presents as a midline cervical mass and arises from the descent of the thyroid gland from the foramen cecum?

Answer 35

Thyroglossal duct cyst [May be the only thyroid tissue a patient has.] [UpToDate: The anlage of the thyroid gland forms at the foramen cecum of the tongue, which is located on the dorsum of the tongue posteriorly at the apex of the V-shaped sulcus formed by the circumvallate papillae. During the fourth week of gestation, a ventral diverticulum of the foramen cecum is formed from the first and second pharyngeal pouches (the medial thyroid anlage). This diverticulum, with its narrow neck connected to the tongue, descends in the midline of the neck as the thyroglossal tract to the position of the normal thyroid in the base of the neck, where the thyroid lobes separate, by the seventh week. The path of descent is usually anterior to the hyoid bone, but may be posterior to or through the bone, and ends on the anterior surface of the first few tracheal rings. The tract usually atrophies and disappears by the tenth week of gestation. Portions of the tract and remnants of thyroid tissue associated with it may persist at any point between the tongue and the thyroid. The pyramidal lobe can be thought of as the most caudal remnant of this tract and is present in approximately one-third of normal subjects. The lateral thyroid anlage, consisting of the C-cell precursors, which arises from the neural crest portion of the fourth pharyngeal pouch, ultimately fuses with the descended medial anlage. The pyramidal lobe usually arises from the isthmus of the thyroid, but may arise from the medial aspect of one of the thyroid lobes or both lobes. A thyroglossal duct cyst arises as a cystic expansion of a remnant of the thyroglossal duct tract. The stimulus for the expansion is not known; one postulate is that lymphoid tissue associated with the tract hypertrophies at the time of a regional infection, thereby occluding the tract with resultant cyst formation. Many cystic remnants of the thyroglossal tract are never detected clinically; a postmortem study of 200 adults found a 7 percent incidence of thyroglossal duct cysts.]

Question 36

What are the types and frequencies of choledochal (biliary) cysts?

Answer 36

Type 1: Fusiform dilation of the entire common bile duct, mildly dilated common hepatic duct, normal intrahepatic ducts - 85% Type 2: A true diverticulum that hangs off the common bile duct - 3% Type 3: Dilation of the distal intramural common bile duct, involves the sphincter of Oddi - 1% Type 4: Multiple cysts, both intrahepatic and extrahepatic - 10% Type 5: Caroli's disease: Intrahepatic cysts leading to hepatic fibrosis, may be associated with congenital hepatic fibrosis and medullary sponge kidney - 1% [UpToDate: Type I cysts - 50-85% Type II cysts - 2% Type III cysts - 1-5% Type IV cysts - 15-35% Type V cysts - 20%]

Question 37

What is the most common location of intestinal atresia?

Answer 37

Jejunum [Can be multiple atresias in a single patient.] [UpToDate: The most common site of intestinal atresia is the small intestine (jejunum and ileum). The incidence of jejunal and ileal atresia ranges from one in 1500 to one in 12,000 births. Duodenal atresia occurs in one in 10,000 to 40,000 births and represents up to 60% of intestinal atresias. Approximately 30% of infants with duodenal atresia have a chromosomal anomaly, primarily Down syndrome. The colon is the least affected site of atresia and accounts for 7-10% of cases. The incidence is approximately one in 40,000 live births.]

Question 38

How does bronchopulmonary sequestration usually present later in life?

Answer 38

Most commonly presents with infection, but can also have respiratory compromise or an abnormal CXR [UpToDate: The clinical presentation of BPS is variable and depends upon the type, size, and location of the lesion. Many cases are initially detected by routine prenatal ultrasound examination. Most affected newborns are asymptomatic. If symptomatic, BPS usually presents with respiratory distress in the neonatal period. Intralobar sequestration (ILS) or hybrid forms often present later in life, with infection. Presentation with infection is less likely with extralobar sequestration (ELS). ELS may also be diagnosed incidentally on a chest radiograph taken for other reasons.]

Question 39

What is the appropriate treatment for Hirschsprung's disease?

Answer 39

Need to resect colon until proximal to where ganglion cells appear [May need to bring up a colostomy initially, eventually connect the colon to the anus (Soave or Duhamel procedure).] [UpToDate: The mainstay of treatment is surgery. The goals are to resect the affected segment of the colon, bring the normal ganglionic bowel down close to the anus, and preserve internal anal sphincter function. Many surgical techniques have been developed. The choice among them usually is based upon surgeon preference, since the overall complication rates and long-term results are similar. The traditional operation was an abdominoperineal pull-through in two or three stages, in which patients initially underwent a diverting colostomy (to allow the dilated bowel to decompress) with definitive repair performed later. However, most centers now perform the procedure in one stage, an approach that does not appear to increase complication rates. Laparoscopic-assisted and transanal repairs are gaining in popularity, and are now preferred over the open procedures in most centers. The results seem to be equal to the traditional abdominoperineal pull-through with the added benefit of earlier resumption of full feeds, less pain, shorter hospitalization, and less conspicuous scars. However, one case series with 3-16 years follow-up suggests that a transanal approach may be associated with a higher frequency of fecal incontinence compared with a transabdominal approach (54% vs 25% for daily fecal incontinence). Accordingly, the frequency of internal anal sphincter defects identified by endosonography was also higher in patients undergoing a transanal approach (69% vs 19%). These findings should be confirmed with data from other centers and with different lengths of follow-up to fully understand the implications of operative approach.]

Question 40

What is the second most common type of esophageal atresia/tracheoesophageal fistula?

Answer 40

Type A [Esophageal atresia and no fistula. Symptoms: new born spits up feeds, has excessive drooling, and respiratory symptoms with feeding; Unable to place NG tube in stomach. patients have a gasless abdomen on abdominal xray.]

Question 41

What is the approach to acute fluctuant vs asymptomatic lymphadenitis in a child?

Answer 41

Usual cause is an upper respiratory infection or pharyngitis If fluctuant: FNA, culture and sensitivity, and antibiotics; may need incision and drainage if it fails to resolve If asymptomatic: Antibiotics for 10 days; excisional biopsy if no improvement (This is lymphoma until proven otherwise) [UpToDate: There are numerous infectious and noninfectious causes of cervical lymphadenitis. Important aspects of the history and examination include onset, laterality, duration, and qualities of the lymphadenitis; associated symptoms (eg, fever, weight loss) and examination findings (eg, conjunctivitis, rash, hepatosplenomegaly); immunizations status; and exposures. Acute bilateral cervical lymphadenitis usually is caused by a self-limited viral upper respiratory infection and requires only monitoring unless it is accompanied by severe symptoms, progresses, or persists. Acute bilateral cervical lymphadenitis usually does not require specific treatment. Acute unilateral lymphadenitis is usually caused by Staphylococcus aureus or group A Streptococcus (GAS). The evaluation and management depend upon the child's clinical status and the course of lymphadenitis. Unilateral subacute/chronic cervical lymphadenitis is usually caused by cat scratch disease or nontuberculous mycobacterial (NTM) infection. However, the possibility of malignancy must be considered, particularly in adolescents. Bilateral subacute/chronic cervical lymphadenitis is usually caused by Epstein-Barr virus (EBV) or cytomegalovirus (CMV). For children in whom the etiology of lymphadenitis remains uncertain after the initial evaluation or the lymphadenitis has persisted for six to eight weeks with no response to antimicrobial therapy, additional testing, including excisional biopsy, may be indicated to assess uncommon or rare infectious and noninfectious causes of cervical lymphadenitis.]

Question 42

How many umbilical veins and arteries are there?

Answer 42

2 arteries, 1 vein [The umbilical arteries originate from the internal iliac arteries, which in the fetus carry de-oxygenated blood.]

Question 43

What does VACTERL syndrome include?

Answer 43

* Vertebral * Anorectal (imperforate anus) * Cardiac * TE fistula * Radius/renal * Limb anomalies

Question 44

At what age do neuroblastomas usually present?

Answer 44

By age 1-2 years [Children \< 1 year old have the best prognosis.] [UpToDate: Neuroblastoma is almost exclusively a disease of children. It is the third most common childhood cancer, after leukemia and brain tumors, and is the most common solid extracranial tumor in children. More than 600 cases are diagnosed in the United States each year, and neuroblastoma accounts for approximately 15% of all pediatric cancer fatalities. Incidence rates are age-dependent. The median age at diagnosis is 17.3 months, and 40% of patients are diagnosed before one year of age. Neuroblastomas are the most common extracranial solid malignant tumor diagnosed during the first two years of life, and the most common cancer among infants younger than 12 months, in whom the incidence rate is almost twice that of leukemia (58 versus 37 per one million infants). The incidence of neuroblastoma is greater among white than black infants (ratio of 1.7 and 1.9 to 1 for males and females, respectively), but little if any racial difference is apparent among older children. Neuroblastoma is slightly more common among boys compared with girls.]

Question 45

What is the appropriate treatment for laryngomalacia?

Answer 45

Surgical tracheostomy reserved for a very small number of patients [Most children outgrow this condition by 12 months of age.] [UpToDate: The management of laryngomalacia depends upon the severity. In the vast majority of otherwise normal children, laryngomalacia is not dangerous and resolves spontaneously. Infants with mild laryngomalacia (intermittent mild stridor with no other symptoms) may be followed clinically with frequent monitoring to make sure that weight gain is adequate. Infants known to have associated gastroesophageal reflux should be treated for reflux. There is no good scientific basis to guide the decision between a full diagnostic evaluation and empiric therapy for gastroesophageal reflux in the child with laryngomalacia. Medical management, including acid suppression, swallowing therapy, and/or high-calorie formula, is adequate therapy in some infants with mild-to-moderate disease. Infants with moderate or severe laryngomalacia (stridor with feeding difficulty, dyspnea, tachypnea, cyanosis, apnea) should be referred to an otolaryngologist for full endoscopic evaluation and possible intervention. Children with severe laryngomalacia often benefit from surgery to remove redundant supraglottic tissue. In experienced hands, this surgery can produce dramatic improvements in breathing, feeding, and growth with little morbidity. Parents report improved quality of life for children undergoing supraglottoplasty. Two meta-analyses found that for children with obstructive sleep apnea due to laryngomalacia, supraglottoplasty is associated with improvement in the apnea-hypopnea index and oxygen saturations; however, most children have residual disease after the procedure. Possible complications include supraglottic or glottic scarring and subsequent chronic aspiration or dysphonia, so surgery should not be undertaken for minimal indications (ie, to ease parental anxiety about noisy breathing).]

Question 46

Obstruction of the nasal passage by either bone or mucous membrane is called what?

Answer 46

Choanal atresia [Usually unilateral. Symptoms include intermittent respiratory distress, poor suckling.] [UpToDate: Choanal atresia is obliteration or blockage of the posterior nasal aperture. Choanal atresia often is associated with bony abnormalities of the pterygoid plates and midfacial growth abnormalities. One etiologic explanation for choanal atresia holds that persistence of the oronasal membrane prevents the joining of the nose and oropharynx. This theory does not account for the associated bony and midface abnormalities. An alternate explanation is that alterations in local growth factors result in small or imperforate choanae. Most cases involve bony and membranous obstruction to varying degrees. The separation of choanal atresia into bony or membranous types is artificial. Choanal atresia occurs in approximately one in 7000 live births. It is more common in girls than boys. Approximately two-thirds of cases are unilateral. The presentation of choanal atresia varies depending upon whether one or both sides are involved. Individuals with unilateral choanal atresia typically present later in life with unilateral nasal discharge and/or obstruction. Infants with bilateral choanal atresia typically present with upper airway obstruction, noisy breathing, or cyanosis that worsens during feeding and improves when the infant cries. The diagnosis should be suspected if a number 5 or 6 French catheter cannot be passed from the nose to oropharynx a distance of at least 32 mm. Qualitative measure of nasal airflow, such as the movement of a wisp of cotton under the nostrils or fogging of a mirror adds support to the clinical diagnosis. The diagnosis of choanal atresia is confirmed by computed tomography with intranasal contrast that shows narrowing of the posterior nasal cavity at the level of the pterygoid plate. Choanal atresia may occur as an isolated anomaly or as part of a multiple congenital anomaly syndrome (eg, Treacher-Collins, CHARGE (coloboma of the iris or choroid, heart defect, atresia of the choanae, retarded growth and development, genitourinary abnormalities, and ear defects with associated deafness), Kallmann, VACTERL/VATER association (vertebral anomalies, anal atresia, cardiac defects, tracheoesophageal fistula and/or esophageal atresia, renal and radial anomalies, and limb defects), Pfeiffer). Other congenital anomalies are present in 50% and 60% of individuals with unilateral and bilateral choanal atresia, respectively.]

Question 47

What is the most common sign of Hirschsprung's disease?

Answer 47

Infants fail to pass meconium in 1st 24 hours [Can also present in older age groups as chronic constipation (age 2-3). Get distension; occasionally get colitis. Can get explosive release of watery stool with anorectal exam.] [UpToDate: The majority of patients with Hirschsprung disease (HD) are diagnosed in the neonatal period. Patients present with symptoms of distal intestinal obstruction: bilious emesis, abdominal distension, and failure to pass meconium or stool. The diagnosis can be suggested by a delay in passage of the first meconium (\>48 hours of age). By 48 hours of life, 100% of normal full-term neonates will pass meconium. In contrast, 50-90% of infants with Hirschsprung disease will fail to pass meconium within the first 48 hours of life. However, passage of stool within the first one to two days of life does not exclude the diagnosis. There may be an explosive expulsion of gas and stool after the digital rectal examination (squirt sign or blast sign), which may relieve the obstruction temporarily. Affected infants also may present initially with enterocolitis, a potentially life-threatening illness in which patients have a sepsis-like picture with fever, vomiting, diarrhea, and abdominal distension, which can progress to toxic megacolon. Patients with enterocolitis require fluid resuscitation, intravenous (IV) antibiotic therapy including coverage for anaerobic bacteria, rectal irrigations, and, in rare cases, an emergency colostomy. A rare complication of HD is volvulus, which can affect the sigmoid and less commonly the transverse colon and cecum. Patients with less severe disease (usually because a smaller segment of the colon is affected) may not be diagnosed until later in childhood; in about 10 percent of individuals, HD is diagnosed after three years of age. Such patients typically have a history of chronic constipation and failure to thrive. Although uncommon, HD can be newly diagnosed in adulthood. Patients present with symptoms of abdominal distension and a long history of refractory constipation without fecal incontinence. Some of these patients may have "ultra-short segment" HD, which is described below.]

Question 48

What differentiates a congenital inguinal hernia from a hydrocele?

Answer 48

A hernia has extension into the internal ring [UpToDate: A hernia is the protrusion of a portion of an organ or tissue through an abnormal opening in the wall that normally contains it. A hydrocele is a fluid-filled collection that can occur anywhere along the path of descent of the testis or ovary. An acute hydrocele generally involves only the scrotum; no mass is palpated in the area of the internal ring. This is in contrast to a communicating hydrocele, which is, in fact, a hernia containing peritoneal fluid. Hydroceles transilluminate and usually are cystic, irreducible, and nontender. An acute hydrocele of the spermatic cord may occasionally be difficult to distinguish from an incarcerated inguinal hernia.]

Question 49

What is Cantrell pentalogy?

Answer 49

1. Cardiac defects 2. Pericardium defects (usually at diaphragmatic pericardium) 3. Sternal cleft or absence of lower sternum 4. Diaphragmatic septum transversum absence 5. Omphalocele [Associated with omphalocele.] [UpToDate: Omphalocele associated with pulmonary hypoplasia from Pentalogy of Cantrell (epigastric omphalocele, defective sternum, ventral diaphragmatic defect, intrinsic cardiac abnormality, anterior pericardial deficiency), trisomy 13 or 18, or triploidy carries a dismal prognosis; therefore, interventions such as fetal monitoring and cesarean delivery are not recommended in these cases. Management should be individualized, however, since, with contemporary neonatal and surgical care, survival is possible in some milder cases.]

Question 50

What causes gastroschisis to occur?

Answer 50

Intrauterine rupture of umbilical vein [Does not have a peritoneal sac. Occurs to the right of midline. Stiff bowel from exposure to amniotic fluid. Only 10% are associated with congenital anomalies (not including malrotation).] [UpToDate: Several hypotheses have been proposed to explain the pathogenesis of gastroschisis; all involve defective formation or disruption of the body wall in the embryonic period, with subsequent herniation of bowel: * Failure of mesoderm to form in the body wall * Rupture of the amnion around the umbilical ring * Abnormal involution of the right umbilical vein leading to weakening of the body wall * Disruption of the right vitelline artery with subsequent body wall damage * Abnormal folding of the body wall resulting in a ventral body wall defect Gene polymorphisms that interact with environmental factors, such as smoking, may play a role in pathogenesis. The maternal immune response to new paternal (fetal) antigens may also play a role. There is no high-quality evidence that any drug causes gastroschisis, but a possible association has been reported for aspirin, ibuprofen, and vasoconstrictive agents (eg, pseudoephedrine). Use of acetaminophen in the first trimester has been reported both to lower the risk of gastroschisis and to increase the risk. The prevalence of gastroschisis appears to be higher in areas where surface water agricultural chemical levels are high and when conception occurs in the spring, the time when agricultural chemicals (eg, atrazine) are commonly applied. The possible role of these chemicals in the pathogenesis of gastroschisis requires further study as an association with adverse birth outcomes has not been reported consistently. Most cases have no extraintestinal abnormalities. In a study of pooled data from 24 international birth defects registries including over 3300 cases of gastroschisis, only approximately 10% of gastroschisis cases were associated with major unrelated defects, approximately 2% of cases were part of a recognized syndrome, and cardiac anomalies were detected in 2-3% of cases. However, this may be due to ascertainment bias. A study using a prospectively collected database including almost 4700 infants with gastroschisis discharged from 348 neonatal intensive care units in North America reported associated anomalies in 8% and cardiac anomalies in 1%, but others have reported associated anomalies in as many as one-third of cases.]

Question 51

What is the appropriate treatment for a duplication cyst?

Answer 51

Resect cyst [Most commonly occur in the ileum; often on the mesenteric border.] [UpToDate: Duplication cysts (DC) are benign, rare anomalies that arise during early embryonic development. They are most frequently found in the proximal small intestine, although they can also be found in the esophagus, stomach, and colon. There are two general types: those that are adjacent to the lumen (having lost communication to the gastrointestinal wall), and those that are tubular and communicate directly with the lumen. DC are lined with stratified, ciliated, or columnar epithelium and contain a mucoid fluid. The cysts are typically discovered incidentally on endoscopy or radiologic imaging since they only uncommonly cause symptoms. Complications are rare but may include dysphagia, abdominal pain, bleeding, and pancreatitis when located near the ampulla of Vater. While they are believed to have a low malignant potential, case reports have described malignant transformation. Endoscopic appearance — DC can appear as a bulge with normal overlying mucosa, or as a diverticulum that can vary in size from several millimeters to over 5 cm. They have a smooth and regular appearance without mucosal irregularities. They are most commonly diagnosed by computed tomography (CT) scan or magnetic resonance imaging since they are infrequently seen endoluminally. Endosonographic findings — DC are usually anechoic homogeneous lesions with regular margins arising from the submucosal (third layer) or extrinsic to the gastrointestinal wall. Their walls can be characterized by three- or five-layer structures. They also can contain septae, fluid levels, or echogenic material consisting of layering debris or mucin. Occasionally, a cyst appears as a solid lesion on CT scan due to the higher density elicited from debris particles within a cyst. EUS is helpful in discriminating a duplication cyst from a solid mass. Diagnosis and treatment — The diagnosis can usually be made by the characteristic endoscopic and endosonographic appearance. EUS-guided fine-needle aspiration (FNA) has been used to establish a diagnosis of an esophageal cyst, although this is not necessary and has a risk of causing infection. Management of asymptomatic cysts is usually expectant, but resection has been recommended based upon their potential for complications, including malignant transformation. However, prospective studies evaluating the natural history of duplication cysts are lacking. When symptomatic, DC can be treated surgically or endoscopically. Successful endoscopic management of endoluminal cysts has been described using FNA, needle-knife cystostomy, and, when small, snare excision.]

Question 52

What is the appropriate treatment for biliary atresia?

Answer 52

Kasai procedure (hepaticoportojejunostomy) [1/3 get better, 1/3 go on to liver transplant, and 1/3 die. Involves resecting the atretic extrahepatic bile duct segment. Need to perform Kasai procedure before age 3 months, otherwise get irreversible liver damage.] [UpToDate: If biliary atresia (BA) is confirmed by cholangiogram, a Kasai procedure (hepatoportoenterostomy [HPE]) should be performed promptly. This operation is undertaken in the attempt to restore bile flow from the liver to the proximal small bowel. For this procedure, a roux-en-Y loop of bowel is created by the surgeon and directly anastomosed to the hilum of the liver, following excision of the biliary remnant and portal fibrous plate. If successful, the remaining small patent bile ducts will drain into the roux limb and jaundice will start to resolve in the weeks following surgery. If unsuccessful, bile drainage is not achieved, and the child remains jaundiced. If there is persistent jaundice or elevated serum bilirubin three months after the Kasai, the patient should be referred for liver transplant evaluation. Revision of a non-functioning HPE generally is not recommended. This is because a revisional procedure is unlikely to be effective if the original HPE did not achieve bile drainage, and because the revisional procedure is likely to cause adhesions that increase the technical difficulty of a subsequent transplant procedure. However, in patients in whom the initial HPE was successful, revisional HPE may be appropriate if the patient abruptly develops jaundice, or experiences recurrent episodes of cholangitis but has no other evidence of chronic liver disease. In one report of 24 patients who underwent revisional HPE for these indications, 75% achieved bile drainage and 46% survived with their native liver (mean follow-up 92 months). Even if bile flow is established and cholestasis improves, many patients will have slowly progressive liver disease despite undergoing the Kasai procedure, and the majority of patients with BA will ultimately require liver transplantation. At least 50% of patients who undergo HPE will require liver transplantation by two years of age as a result of primary failure of the Kasai HPE and/or growth failure. The patient's age at the time of HPE can predict native liver survival at later time points. As an example, among those patients who undergo HPE ≤30 days of life, the chance of native liver survival at four years of age is nearly 50%, whereas among those who underwent HPE between 31 and 90 days of life, the chance of native liver survival at four years of age is 36%. Thus, the vast majority of individuals with BA will eventually require liver transplantation. Nonetheless, the Kasai HPE obviates the need for liver transplantation in a substantial minority and significantly delays the liver transplantation for many others. Pre-emptive transplant is avoided because of the advantages of transplanting older, larger patients and because of the potential for improved transplantation therapies in the future. At one time pre-emptive transplantation was used to avoid the difficulties of performing surgery on a patient with a prior HPE. With modern transplantation techniques, there is no surgical advantage to pre-emptive transplantation. Therefore, HPE is almost always performed first. If bile drainage is achieved, it is likely that transplantation will not be needed for years or decades. Historical series from before the Kasai procedure was introduced in 1968 report a 10% survival rate at age three years of age, as compared with the 35-50% survival rates with native liver at age four years of age.]

Question 53

What causes omphalocele to occur?

Answer 53

Failure of embryonal development [Has peritoneal sac with cord attached. Sac can contain intraabdominal structures other than bowel (ie. liver, spleen, etc.). Defect is at midline. 50% are associated with congenital anomalies.] [UpToDate: Fetal abdominal wall defects result from disturbances in organogenesis during the embryonic period. During the fourth to fifth week of development, the flat embryonic disk folds in four directions and/or planes: cephalic, caudal, and right and left lateral. Each fold converges at the site of the umbilicus, thus obliterating the extraembryonic coelom. The lateral folds form the lateral portions of the abdominal wall, and the cephalic and caudal folds make up the epigastrium and hypogastrium. Rapid growth of the intestines and liver also occurs at this time. During the sixth week of development (or eight weeks from the last menstrual period), the abdominal cavity temporarily becomes too small to accommodate all of its contents, resulting in protrusion of the intestines into the residual extraembryonic coelom at the base of the umbilical cord. This temporary herniation is called physiologic midgut herniation and is sonographically evident the 9th-11th postmenstrual weeks (up to crown rump length 45 mm). Reduction of the hernia occurs by the 12th postmenstrual week; thus beyond the 12th week a midgut herniation is no longer physiological. If the extraembryonic gut fails to return to the abdominal cavity, a simple midline omphalocele develops covered by the two-layer amnionic-peritoneal membrane, into which the umbilical cord inserts. In contrast to fetal bowel, the liver does not undergo physiologic migration outside of the abdominal cavity during development. Therefore, the liver is never present in physiologic midgut herniation. If the lateral folds fail to close, a large abdominal wall defect is created through which the abdominal cavity contents, including the liver, can herniate. The result is a liver-containing omphalocele. Omphaloceles are associated with a high frequency of fetal aneuploidy when they contain only small bowel (ie, the liver is intracorporeal). An extracorporeal liver often, but not invariably, is associated with a normal fetal karyotype.]

Question 54

What is the appropriate treatment for malrotation?

Answer 54

Resect Ladd's bands, counterclockwise rotation (may require multiple turns), place cecum in LLQ (cecopexy), place duodenum in RUQ, and appendectomy. [UpToDate: Malrotation, regardless of the age of the patient and the presence of symptoms, is treated surgically with a Ladd procedure. This procedure begins with reduction of the volvulus, if present. Since the appendix ends up in the left mid- to upper abdomen, an appendectomy is performed as well. If, after surgical reduction of a volvulus, the viability of the bowel is in question, the abdomen can be closed and the bowel reevaluated after 24-36 hours. If frankly necrotic bowel is present, it is resected and stomas are created. The Ladd procedure for malrotation can be performed laparoscopically in the absence of volvulus or bowel ischemia, particularly in the older child or adult.]

Question 55

What is a choledochal (biliary) cyst and how should it be managed?

Answer 55

Cystic dilatation of the biliary tree. Needs to be resected [Risk of cholangiocarcinoma, pancreatitis, cholangitis, and obstructive jaundice. It is caused by reflux of pancreatic enzymes into the biliary system in utero.] [UpToDate: Biliary cysts are cystic dilations that may occur singly or in multiples throughout the biliary tree. They were originally termed choledochal cysts due to their involvement of the extrahepatic bile duct. However, the original clinical classification was revised in 1977 to include intrahepatic cysts. Biliary cysts are associated with significant complications such as ductal strictures, stone formation, cholangitis, rupture, and secondary biliary cirrhosis. In addition, certain types of biliary cysts have a high risk of malignancy. Congenital cysts may result from an unequal proliferation of embryologic biliary epithelial cells before bile duct cannulation is complete. Fetal viral infection may also have a role, as reovirus ribonucleic acid (RNA) has been isolated from biliary tissue of neonates with infantile biliary obstruction and biliary cysts. In addition, cyst formation may be the result of ductal obstruction or distension during the prenatal or neonatal period. In a sheep model, bile duct ligation in neonates led to cyst formation, whereas duct ligation in adult animals led to gallbladder distension.]

Question 56

What congenital condition is characterized by lung tissue that has an anomalous systemic arterial supply?

Answer 56

Bronchopulmonary sequestration (BPS) [UpToDate: BPS is a nonfunctioning mass of lung tissue, with airway and alveolar elements, that lacks normal communication with the tracheobronchial tree, and that receives its arterial blood supply from the systemic circulation. The subtypes are classified anatomically, as follows: 1. Intralobar sequestration (ILS) – An intralobar pulmonary sequestration (also known as intrapulmonary sequestration), is located within a normal lobe and lacks its own visceral pleura. ILS accounts for about 75 percent of BPS. 2. Extralobar sequestration (ELS) – An extralobar pulmonary sequestration (also known as extrapulmonary sequestration), is located outside the normal lung and has its own visceral pleura. Occasionally, it is located below the diaphragm. ELS accounts for about 25 percent of BPS and is more likely to be associated with other congenital anomalies. 3. Hybrid BPS/CPAM lesions – In a hybrid lesion, BPS (either ILS or ELS) occurs in combination with a congenital pulmonary airway malformation (CPAM). These hybrid lesions have histologic features of CPAM and a blood supply from a systemic artery, and have been reported in a substantial proportion of cases of BPS. 4. Bronchopulmonary-foregut malformation (BPFM) – This term is usually used to refer to a rare variant of sequestration, in which the sequestered lung tissue is connected to the gastrointestinal tract. This may occur in either ILS or ELS. Occasionally, BPFM is used as a general term to include all foregut malformations.]

Question 57

What is the appropriate treatment for a congenital pulmonary airway malformations (also known as congenital cystic adenoid malformation)?

Answer 57

Lobectomy [UpToDate: In patients with CPAM that is causing any respiratory symptoms (respiratory distress or tachypnea), we recommend surgical resection rather than observation (Grade 1A). All resected cysts should be carefully examined for evidence of malignancy. Asymptomatic infants with a prenatal diagnosis of CPAM should be evaluated with a chest radiograph in the neonatal period. Subsequent management depends on whether there are characteristics that suggest a high risk of complications. For infants and children with high-risk characteristics (large lesions on chest radiograph, bilateral or multifocal cysts, a family history of pleuropulmonary blastoma-associated conditions, or pneumothorax), we suggest early surgical resection rather than observation (Grade 2C). These infants should be evaluated with CT or MRI prior to surgery to confirm the diagnosis and further evaluate the lesion. For infants and children with small lesions and none of the other high-risk features outlined above, either elective surgical resection or conservative management with observation are reasonable options. If surgical resection is chosen for such patients, it is usually performed after the neonatal period but before 12 months of age. If observation is chosen, we suggest close clinical follow-up during the first year of life to monitor for the development of symptoms of respiratory distress or infection, as well as imaging with CT or MRI by six months of age and annually thereafter. For infants who are asymptomatic at birth, the risk of developing infection is not well delineated. It is clear that some of these infants will develop infection during the first few years of life if surgery is not performed, but the estimates of the risk for infection ranges from 3-30%.]

Question 58

What is the appropriate treatment for a congenital inguinal hernia?

Answer 58

If able to reduce, then do elective repair with high ligation within 24 hours of reduction. Emergent operation if not able to reduce. [Consider exploring the contralateral side if left sided, female, or child [UpToDate: The management of inguinal hernia ultimately requires surgical repair. Incarcerated hernias must be emergently reduced: * Children with a compatible history and those with a reducible mass should be referred to a surgeon for evaluation. Because incarceration can occur in children awaiting elective repair, particularly in those less than one year of age, we suggest that repair be performed soon after diagnosis (Grade 2B). * We recommend that manual reduction be attempted for children with an incarceration without signs of peritoneal irritation (Grade 1B). Immediate referral to a surgeon is recommended if manual reduction is not successful. Children with an incarcerated hernia should have nothing by mouth, in case emergent surgical reduction is required. * Hernias in females are caused by the persistence of the diverticulum of Nuck and contain the suspensory ligament of the ovary. Because of the significant likelihood that reproductive organs are within the hernial sac, the clinician should attempt a gentle reduction and then obtain an ultrasound (US) if not successful. In patients in whom an incarcerated ovary is suspected, ultrasound first, if available, is an alternative approach. If the US indicates that reproductive organs are not present, then further efforts at reduction are appropriate. Following successful manual reduction of an incarcerated inguinal hernia, children should be referred to a surgeon. We suggest that definitive hernia repair be performed within five days (within two days for infants born prematurely) of the reduction (Grade 2B).]

Question 59

What is the treatment for esophageal atresia/tracheoesophageal fistula?

Answer 59

Right extrapleural thoracotomy for most [Perform primary repair and place G-tube. Azygous vein often needs to be divided. Complications include GERD, leak, empyema, stricture, and fistula. In infants that are premature and \<2,500g or infants that are sick, place a replogle tube and treat respiratory symptoms, place a G-tube, and delay repair. Survival is related to birth weight and associated anomalies.] [Wikipedia: A Replogle tube is a medical device used in the treatment of babies with oesophageal atresia. It is a double-lumen tube which is inserted through the baby's nostril into the blind-ending oesophageal pouch and used to drain saliva.]

Question 60

What is the most common cause of duodenal obstruction after newborn period (\> 1 week old)?

Answer 60

Malrotation [UpToDate: Rotational anomalies occur as a result of an arrest of normal rotation of the embryonic gut. They are often associated with other gastrointestinal abnormalities, but can also occur in otherwise healthy children and adults. Vomiting, which may or may not be bilious, occurs in \>90 percent of newborns with volvulus and is by far the most common presenting symptom of malrotation in infancy. It is often accompanied by abdominal distension and tenderness. Hematochezia is a worrisome sign of bowel ischemia. The presentation of intestinal malrotation in older children and adults is variable and often insidious. They too may present with midgut volvulus, but more often have intermittent vomiting or abdominal pain. Less common presentations include failure to thrive, solid food intolerance, malabsorption, chronic diarrhea, pancreatitis, peritonitis, biliary obstruction, motility disorders, or chylous ascites.]

Question 61

Which immunoglobulins are present at birth?

Answer 61

* IgA from mother's milk * IgG crosses the placenta

Question 62

What percent of infants with duodenal atresia have Down's syndrome?

Answer 62

20% [Treatment is resuscitation followed by duodenoduodenostomy or duodenojejunostomy.] [UpToDate: Duodenal atresia occurs in one in 10,000 to 40,000 births and represents up to 60% of intestinal atresias. Approximately 30% of infants with duodenal atresia have a chromosomal anomaly, primarily Down syndrome.]

Question 63

Where do neuroblastomas usually occur?

Answer 63

The adrenal gland [Can occur anywhere along the sympathetic chain.] [UpToDate: Neuroblastomas can arise anywhere throughout the sympathetic nervous system. The adrenal gland is the most common primary site (40%), followed by abdominal (25%), thoracic (15%), cervical (5%), and pelvic sympathetic ganglia (5%). Less commonly, tumors arise within the central or autonomic nervous systems. In approximately 1 percent of cases, a primary tumor cannot be identified. Neuroblastoma metastasizes to lymph nodes, bone marrow, cortical bone, dura, orbits, liver, and skin, and less frequently to pulmonary and intracranial sites.]

Question 64

What is the appropriate treatment for Meckel's diverticulum?

Answer 64

Resection with symptoms, suspicion of gastric mucosa, or narrow neck [Diverticulitis involving the base or if the base is \> 1/3 the size of the bowel, need to perform segmental resection] [UpToDate: Symptomatic Meckel’s diverticulum should be resected in all patients (children and adults) to relieve symptoms. Whether an incidentally discovered, asymptomatic diverticulum should be removed is controversial in children and adults. For children and adults with asymptomatic Meckel’s diverticulum identified on imaging studies, we suggest not performing elective resection (Grade 2B). For patients with a normal-appearing Meckel’s diverticulum identified on abdominal exploration, we use a selective approach that takes into consideration the patient’s clinical status, their lifelong risk of Meckel’s-related complications, and anatomic features associated with developing symptoms. * For most children to young adulthood, we suggest resection of the normal-appearing Meckel’s diverticulum given an increased lifelong risk for complications (Grade 2C). * For otherwise healthy, young adults (\<50 years of age), we suggest resection of the normal-appearing Meckel’s diverticulum if there is a palpable abnormality, the Meckel’s diverticulum is longer than 2 cm, or the Meckel’s diverticulum has a broad base (\>2 cm) (Grade 2C). * For patients \>50 years of age, and patients with significant comorbidities, we suggest not resecting the normal-appearing Meckel’s diverticulum, unless there is a palpable abnormality associated with the diverticulum (Grade 2C). For patients undergoing resection of a symptomatic Meckel’s diverticulum due to gastrointestinal bleeding, we suggest a segmental small bowel resection rather than simple diverticulectomy (Grade 2C). Segmental resection removes the ectopic mucosa within the diverticulum responsible for the bleeding and adjacent ulcerated tissue. Death related to resection of Meckel's diverticulum is rare. The anticipated complication rate for Meckel’s resection is overall about 5%. The most common complications are surgical site infection, prolonged postoperative ileus, and anastomotic leak, which are essentially those of any small bowel surgery.]

Question 65

Any child with bilious vomiting needs what test?

Answer 65

A UGI to rule out malrotation [Malrotation is diagnosed with a UGI. Duodenum does not cross midline; duodenal-jejunal junction displaced to the right.] [UpToDate: The diagnosis of intestinal malrotation should be suspected in any infant who presents with bilious emesis, acute duodenal obstruction, or abdominal tenderness associated with hemodynamic deterioration. In a case series of 52 infants under one year of age, vomiting was the presenting symptom in 93% of patients. In older children and adults, abdominal pain is the most common symptom and may present with abrupt onset over hours or days or as chronic intermittent pain over weeks, months, or years. Intermittent vomiting, chronic diarrhea, malabsorption, or failure to thrive comprises other potential presenting symptoms. When malrotation is complicated by volvulus, it is a potentially life-threatening condition and requires emergent evaluation and treatment. If the child has volvulus with signs of systemic decompensation (eg, hematemesis, hematochezia, abdominal distension, peritonitis, and shock), no additional evaluation is needed. The child should be rapidly resuscitated and immediately taken to surgery for exploration. If the child is hemodynamically stable, the diagnosis should be confirmed by radiologic evaluation. This evaluation typically begins with plain radiographs, which are rarely diagnostic but are important to exclude obvious perforation indicated by pneumoperitoneum. Plain radiographs are followed by an upper gastrointestinal (GI) contrast series, which is the best examination to visualize the duodenum in infants and children. It should be performed, whenever possible, under fluoroscopy by an experienced pediatric radiologist. Barium enema and ultrasonography can be useful adjuncts when abnormal findings are present, but normal findings do not exclude malrotation. Computed tomography of the abdomen with intravenous contrast is not the recommended diagnostic study for malrotation in infants and children but may be appropriate in adults. Radiographic findings suggestive of malrotation are listed in the table.]

Question 66

What is the rule of 2s for Meckel's diverticulum?

Answer 66

* 2 feet from ileocecal valve * 2% of the population * 2% are symptomatic * 2 tissue types (pancreatic - most common, gastric - most likely to be symptomatic) [UpToDate: The rule of twos is the classic description of the essential features of Meckel's diverticulum. It states that * Meckel’s occurs in about 2 percent of the population * Male-to-female ratio of 2:1 * Located within two feet from the ileocecal valve * Can be two inches in length, although, in practice, the size of a Meckel’s diverticulum can vary * Approximately 2-4% of patients develop a complication over the course of their lives, typically before the age of two. * A Meckel’s diverticulum that bleeds is usually lined by two different types of mucosa: the native intestinal mucosa and a heterotopic mucosa. The most common type of heterotropic mucosa is gastric; pancreatic or colonic heterotropic mucosa have also been reported.]

Question 67

What is the most cause of airway obstruction in infants?

Answer 67

Laryngomalacia [Symptoms include intermittent respiratory distress and stridor exacerbation in the supine position. Caused by immature epiglottis cartilage with intermittent collapse of the epiglottis airway. Most children outgrow this by 12 months.] [UpToDate: Laryngomalacia refers to collapse of the supraglottic structures during inspiration. It is the most common congenital anomaly of the larynx and is also called congenital laryngeal stridor. It is distinct from tracheomalacia (an abnormally compliant trachea), which has a different clinical presentation. The etiology of laryngomalacia is not clearly defined, and different mechanisms may apply in different infants. Proposed mechanisms include delayed maturation or "hypotonia" of the supporting cartilaginous structures of the larynx, redundant soft tissue in the supraglottis, a foreshortened or tight aryepiglottic fold, underlying neuromuscular disorders, and supraglottic edema (possibly related to gastroesophageal reflux). In histologic studies, surgically excised supraglottic tissues from infants with laryngomalacia are not distinct from supraglottic tissues from infants without laryngomalacia, weakening the "malacia" or soft-cartilage theory. The frequent concurrence of gastroesophageal reflux, the variation in severity with state of consciousness, and the new onset of laryngomalacia after neurologic injuries support the hypothesis that it is a neuromuscular disorder.]

Question 68

What is the appropriate treatment for intussusception?

Answer 68

Reduce with air-contrast enema (80% successful); no surgery required if reduced [Max pressure with air-contrast enema - 120 mm Hg. Max column height with barium enema - 1 meter (3 feet). High perforation risk beyond these values - need to proceed to OR if you have reached these values. Need to got to OR with peritonitis or free air, or if unable to reduce. When reducing in the OR, do not place traction on proximal limb of bowel; need to apply pressure to the distal limb. Usually do not require resection unless associated with lead point (Meckel's, etc.).] [UpToDate: Nonoperative reduction using hydrostatic or pneumatic pressure by enema has high success rates in children with ileocolic intussusception, and is the treatment of choice for a stable child when appropriate radiologic facilities are available. Patients with a long duration of symptoms and/or suspected bowel perforation may need to proceed directly to surgery. Before attempting reduction by enema, the patient should be stabilized and resuscitated with intravenous fluids. Because there is a risk of perforation during nonoperative reduction, the surgical team should be notified and steps should be taken to ensure that the patient is fit for surgery. Surgical intervention also may be necessary if nonoperative reduction fails to reduce the intussusception. We do not routinely administer antibiotics before performing nonoperative reduction. In some institutions, antibiotics are administered before attempting nonoperative reduction because of the risk of perforation with these procedures. However, the utility of preprocedural antibiotics for nonoperative reduction has not been established. The risk of perforation is only about 1 percent. After successful reduction of an ileocolic intussusception, a temperature higher than 38ºC (100.4ºF) is often noted because of bacterial translocation or the release of endotoxin or cytokines. The patient is also at increased risk to develop recurrent intussusception in the near term, possibly because of residual bowel inflammation, which may itself act as a lead point . As a result, the patient should be observed in the hospital for 12-24 hours. Nasogastric suction usually is maintained until bowel function has returned and the patient has had passage of a bowel movement. Feedings then are advanced as tolerated.]

Question 69

What presents in a child with wheezing that usually improves after 1-2 years and is characterized by elliptical, fragmented tracheal rings instead of C-shaped tracheal rings?

Answer 69

Congenital tracheomalacia [UpToDate: Tracheomalacia is a relatively common anomaly of the upper respiratory tract characterized by dynamic collapse of the trachea during breathing, resulting in airway obstruction. Because most lesions are intrathoracic, airway collapse typically occurs during expiration. Extrathoracic lesions in the cervical trachea are rare and lead to collapse during inspiration. Tracheomalacia is often classified as congenital (primary) or acquired (secondary). There are multiple causes of both congenital and acquired tracheomalacia. Congenital disorders that are associated with tracheomalacia include anything leading to in-utero tracheal compression (eg, congenital heart disease with cardiomegaly or intrathoracic masses), craniofacial anomalies and other genetic syndromes, mucopolysaccharidoses, connective tissue diseases, and others. Acquired causes include those related to chronic barotrauma (from positive pressure ventilation), infection, or inflammation. Signs and symptoms depend upon the location and severity of the tracheal lesion. Intrathoracic lesions typically present with a recurrent harsh, barking, or croup-like cough, whereas extrathoracic lesions cause inspiratory stridor; both may result in respiratory distress. A greater extent of collapse is associated with earlier presentation. Infants and young children with tracheobronchomalacia tend to have more frequent respiratory illnesses and delayed recovery from these illnesses as compared with control patients, but the site and severity of the malacia does not predict the respiratory illness profile. In addition, there is an association between tracheomalacia and protracted bacterial bronchitis; the mechanism of this association has not been established.]

Question 70

What is the treatment for omphalocele?

Answer 70

1. Initially place saline-soaked gauze and resuscitate the patient (can lose alot of fluid from the exposed bowel), TPN, NPO 2. Repair when patient is stable. Attempt to place bowel back in abdomen (may need vicryl mesh silo) 3. Primary closure at a later date if silo used [UpToDate: Delivery room — The immediate care of the newborn with omphalocele involves: * Sterile wrapping of the bowel to preserve heat and minimize insensible fluid loss * Insertion of an orogastric tube to decompress the stomach * Stabilizing the airway to ensure adequate ventilation * Establishing peripheral intravenous access One approach is to wrap the defect with gauze dressings soaked in sterile saline that is thermally neutral and cover the dressing with clear plastic wrap; some use a plastic bag that encloses the infant up to the chest. Excessively wet dressings should be avoided because they can macerate the omphalocele sac and cause the newborn's temperature to drop. Intravenous fluids and broad spectrum antibiotics are administered. Cardiorespiratory and fluid status should be monitored closely and a thorough physical examination performed to identify additional malformations. The neonate should be maintained in a thermoneutral environment. Synopsis of surgical management — Small defects (\<2 cm) can generally be managed by primary direct closure, while medium to large defects require a staged procedure. * Primary closure reduces the risk of bacterial contamination, sepsis, acidosis, and hypothermia, but can be difficult when the size of the abdominal cavity is limited. It should be carried out only if excess tension can be avoided to minimize the risk of wound breakdown. * For moderate to large defects (2-9 cm), most surgeons place a Dacron-reinforced silastic silo as a temporary cover for the bowel. The silo can be reduced gradually over three to seven days in the intensive care unit, after which the infant is returned to the operating room for final closure of the abdominal wall. Reducing a large defect or one that contains liver can be done with Doppler ultrasound guidance to ensure the inferior vena cava and hepatic outflow tract are not compromised during the silo reduction. In unusual cases of an extremely large (\>10 cm) lesion or a premature infant having respiratory difficulties, a topical sclerosing agent can be used as a temporary measure until definitive therapy can be performed on a more stable patient. After omphalocele reduction, the neonate may require prolonged mechanical ventilation because of respiratory difficulties created by the increased intraabdominal pressure, which can impair diaphragm excursion. Infants with very large omphaloceles containing most of the liver may require multiple surgeries and have the potential for long-term morbidity.]

Question 71

What are the staging criteria of Wilms tumor (nephroblastoma)?

Answer 71

* Stage 1: Limited to kidney, completely excised * Stage 2: Beyond kidney but completely excised * Stage 3: Residual nonhematogenous tumor * Stage IV: Hematogenous metastases * Stage 5: Bilateral renal involvement [UpToDate: Staging of Wilms tumor is based upon the anatomic extent of the tumor without consideration for genetic, histologic, or biological markers. Treatment decisions and evaluation of long-term outcome are based upon the Wilms tumor stage.]

Question 72

What are the thickness and length criteria for pyloric stenosis on ultrasound?

Answer 72

* _\>_ 4mm thick * _\>_ 14 mm long [UpToDate: Ultrasound is the procedure of choice if a sonographer with experience in detecting pyloric stenosis is available. In experienced hands, the sensitivity and specificity of ultrasonography for Infantile hypertrophic pyloric stenosis (IHPS) are above 95%, but the accuracy is operator-dependent. IHPS is characterized by a classic “target” sign on transverse view. The measurements most commonly used are pyloric muscle thickness (PMT), pyloric muscle length (PML), and pyloric diameter (PD). Criteria defining the upper limits of normal range from PMT 3-4 mm, PML 15-19 mm, and PD 10-14 mm. Measurements within or above these ranges support the diagnosis of IHPS. These measurements may not be applicable in premature infants. Normal values vary with the size of the infant, so results should be interpreted with caution in particularly small or young infants. Each of these measurements has been touted as the most reliable of the three. However, all three measurements typically are used together in practice. Other less frequently proposed ultrasonographic criteria for the diagnosis of IHPS have included pyloric volume (PV) and pyloric ratio (PR). The PV has been defined as equal to 0.25 pi x PD(2) x PML; infants with IHPS were found to have a significantly higher value than were those without IHPS. The PR is described as PMT/PD and is significantly higher in infants with IHPS, with a sensitivity and specificity of 96% and 94%, respectively. Ultrasonographic diagnosis of IHPS has potential pitfalls. The ultrasonographic findings of pylorospasm may, at least transiently, mimic those of IHPS. The ultrasonographer also must be aware of potential false-positive readings caused by a fluid-filled duodenal bulb and gastric antrum and false-negative interpretation resulting from poor visualization caused by overlying bowel gas. A posterior sonographic view may be helpful in the latter situation.]

Question 73

What is the most common cause of colon obstruction in an infant?

Answer 73

Hirschsprung's disease (Congenital aganglionic megacolon) [UpToDate: Hirschsprung disease (HD) is a motor disorder of the gut, which is caused by the failure of neural crest cells (precursors of enteric ganglion cells) to migrate completely during intestinal development. The resulting aganglionic segment of the colon fails to relax, causing a functional obstruction. In about 80 percent of patients, the disorder affects the rectosigmoid colon (known as short-segment disease). In 15-20% of patients, the aganglionosis extends proximal to the sigmoid colon (known as long-segment disease). In approximately 5 percent, the entire colon is affected (known as total colonic aganglionosis [TCA]), and in rare cases the small bowel may also be involved. Outcomes are generally worse for patients with long-segment as compared with short-segment disease. The majority of patients with Hirschsprung disease (HD) are diagnosed in the neonatal period. Patients present with symptoms of distal intestinal obstruction: bilious emesis, abdominal distension, and failure to pass meconium or stool. The diagnosis can be suggested by a delay in passage of the first meconium (greater than 48 hours of age). By 48 hours of life, 100% of normal full-term neonates will pass meconium. In contrast, 50-90% of infants with Hirschsprung disease will fail to pass meconium within the first 48 hours of life. However, passage of stool within the first one to two days of life does not exclude the diagnosis. There may be an explosive expulsion of gas and stool after the digital rectal examination (squirt sign or blast sign), which may relieve the obstruction temporarily.]

Question 74

What results from a persistent vitelline duct?

Answer 74

Meckel's diverticulum [Found on the antimesenteric border of the small bowel. A Meckel's diverticulum scan with pertechnetate can be obtained if suspicious of Meckel's diverticulum and having trouble locating.] [UpToDate: Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract. It results from incomplete obliteration of the vitelline duct leading to the formation of a true diverticulum of the small intestine. Meckel’s diverticula are uncommon and often clinically silent, particularly in the adult. Asymptomatic Meckel’s diverticulum may be discovered during abdominal exploration for the evaluation of unrelated pathology. Less commonly, they are found incidentally on diagnostic imaging. When symptomatic, Meckel’s diverticulum may present with abdominal pain or symptoms of gastrointestinal bleeding or bowel obstruction.]

Question 75

At what age does intussusception typically occur?

Answer 75

3 months to 3 years [Invagination of one loop of intestine into another. Presents with currant jelly stools (from vascular congestion, not an indication for resection), sausage mass, abdominal distention, RUQ pain, and vomiting.] [UpToDate: Intussusception is the most common cause of intestinal obstruction in infants between 6-36mo of age. Approximately 60% of children are younger than one year old, and 80-90% are younger than two years. Intussusception is less common before three months and after six years of age. When it does occur in these younger or older age groups it is more likely to be associated with a lead point, which may include reactive lymphoid hyperplasia. In a population-wide survey in Switzerland, the yearly mean incidence of intussusception was 38, 31, and 26 cases per 100,000 live births in the first, second, and third year of life, respectively. After the third year of life, the incidence fell to less than half of these rates. Most episodes occur in otherwise healthy and well-nourished children. Intussusception appears to have a slight male predominance, with a male:female ratio of approximately 3:2.]

Question 76

What is the most common renal malignancy in children, has a mean age at diagnosis of 3 years old, often presents as an asymptomatic mass, and can present with hematuria or HTN?

Answer 76

Wilms tumor (Nephroblastoma) [Prognosis is based on tumor grade (anaplastic and sarcomatous variations have worse prognosis).] [UpToDate: In the United States, the annual incidence of renal tumors is about seven cases per million children younger than 15 years, accounting for five percent of all childhood malignancies and approximately 500 new cases per year. Wilms tumor is the most common renal malignancy in children \<15 years old, accounting for about 95% of all cases. In contrast, renal cell carcinoma is more common in the 15 to 19-year-old age group. In the United States, two-thirds of cases of Wilms tumor are diagnosed before five years of age, and 95 percent before 10 years of age. In patients with unilateral involvement, the median age at diagnosis is 43 months in girls and 37 months in boys. Children with bilateral disease are diagnosed at an earlier age (median age, girls at 31 months and boys at 24 months). Patients with associated congenital anomalies, such as aniridia or genitourinary abnormalities, are also diagnosed at an earlier age. The risk of developing Wilms tumor varies among ethnic groups, with a greater risk in African-Americans and a lower risk in the Asian population. Epigenetic differences may contribute to the lower rate of disease in Asian children, as demonstrated by a study that reported infrequent loss of IGF2 imprinting in tumors from Asian patients. Wilms tumor is primarily a sporadic disease, and only 1 to 2 percent of individuals with Wilms tumor have a relative with the disease. In about 10 percent of cases, Wilms tumor occurs as a part of a multiple malformation syndrome, including WAGR, Denys-Drash, and Beckwith-Wiedemann syndromes.]

Question 77

What is the most common mediastinal mass In children?

Answer 77

posterior neurogenic tumors [UpToDate: Two-thirds are symptomatic. The next most common lesions in children are lymphoma and germ cell tumors. In adults, anterior compartment thymomas are the most common mediastinal masses, followed by lymphoma and germ cell tumors. Only one-third of lesions in adults are symptomatic. Neurogenic tumors of the mediastinum represent 19 to 39 percent of all mediastinal tumors and develop from mediastinal peripheral nerves, sympathetic and parasympathetic ganglia, and embryonic remnants of the neural tube. They are most frequent in the posterior compartment of the mediastinum, where they can cause neurologic symptoms by compression.]

Question 78

What complication of Hirschsprung's disease may be rapidly progressive; manifested by abdominal distension, foul-smelling diarrhea, lethargy, and sepsis?

Answer 78

Hirschsprung's colitis [Treatment is rectal irrigation to try and empty the colon. May need emergency colectomy.] [UpToDate: Hirschsprung-affected infants also may present initially with enterocolitis, a potentially life-threatening illness in which patients have a sepsis-like picture with fever, vomiting, diarrhea, and abdominal distension, which can progress to toxic megacolon. Patients with enterocolitis require fluid resuscitation, intravenous (IV) antibiotic therapy including coverage for anaerobic bacteria, rectal irrigations, and, in rare cases, an emergency colostomy. A rare complication of HD is volvulus, which can affect the sigmoid and less commonly the transverse colon and cecum.]

Question 79

What are the two types of congenital diaphragmatic hernia?

Answer 79

* Bochdalek's hernia - most common, located posterior * Morgagni's hernia - Rare, located anteriorly [UpToDate: The diaphragmatic defect is usually (95%) posterolateral (Bochdalek hernia), but may be anterior retrosternal or peristernal (Morgagni hernia), or rarely central.]

Question 80

What causes a congenital inguinal hernia?

Answer 80

Persistent processus vaginalis [Occurs in 3% of infants and is more common in males than females. 60% occur on the right, 30% occur on the left, 10% occur bilaterally.] [UpToDate: The testes appear on the ventromedial aspect of the urogenital ridge on the posterior abdominal wall during the fifth to sixth week of gestation. By the 10th week, they have descended through the coelomic cavity and can be found close to the groin. The processus vaginalis forms during the third month of gestation from an outward protrusion of the peritoneum that lines the ventral abdominal wall and forms a diverticulum at the internal ring. Between the seventh and ninth months of gestation, the testes descend through the internal canal and into the scrotum, pushing the processus vaginalis ahead and protruding into its cavity. Once this process is complete, the processus vaginalis obliterates spontaneously, usually by age two years. The descent of the ovaries is similar to that of the testes except that the ovaries do not leave the abdominal cavity. The diverticulum of Nuck in girls corresponds to the processus vaginalis in boys and is a pocket of peritoneum that extends from the uterus to the labia majora. It normally closes spontaneously at about seven month’s gestation. The closure of the processus vaginalis may be hindered by the persistence of smooth muscle. Myofibroblasts, thought to represent dedifferentiation of smooth muscle and failed apoptosis, were found by electron microscopy in all inguinal hernia sac specimens of 20 children (10 boys and 10 girls). Primary inguinal hernia occurs in 1-5% of all newborns and 9-11% of those born prematurely. Inguinal hernia repair is the most commonly performed surgical procedure in children. Most children with an inguinal hernia have minimal symptoms. The diagnosis is usually made easily and the repair generally is uncomplicated. Strangulation can be avoided when incarceration is promptly recognized and treated. The incidence in boys is three to four times higher than in girls, with the right side being affected more commonly in both sexes. In boys, the incidence is highest during the first year of life and peaks during the first month. The right-sided preponderance is related to the later descent of the right testicle and later obliteration of the processus vaginalis. The incidence of bilateral hernias is approximately 10% in full-term and nearly 50% in premature and low-birth-weight infants.]

Question 81

Do sacrococcygeal teratomas (SCTs) have a high or low malignant potential?

Answer 81

High malignant potential [90% benign at birth (almost all have exophytic component). Great potential for malignancy. 2 month mark is a huge transition: Usually benign \< 2 months, usually malignant \> 2 months. AFP is a good marker.] [UpToDate: SCT is the most common GCT of childhood. In the pediatric population, SCTs account for 40% of all GCTs and up to 78% of all extragonadal GCTs. Rarely, sacrococcygeal teratomas may present in adulthood. SCT is the most frequently recognized fetal neoplasm, with an estimated incidence of about 1 in 27,000. SCT are more common in females than males, with a 3 to 4:1 ratio. SCTs with malignant elements generally are not seen in infants. The incidence of malignant elements within SCTs increases with age. Teratomas often are comprised of cells that represent all three germ cell layers. They have solid, cystic or mixed components. Unlike teratomas in other locations, SCTs often do not have a capsule or pseudocapsule, which contributes to the difficulty in achieving a complete resection. SCTs that contain any malignant elements are considered malignant. Between 11% and 35% of SCTs are malignant, and many of these will have elevated tumor markers. The most common malignant element is a yolk sac component, which produces alpha fetoprotein (AFP). Other malignant elements can include embryonal carcinoma and primitive neuroectodermal tumor (PNET). Microfoci of malignant elements can be missed on pathologic sectioning. Therefore, screening with AFP and beta human chorionic gonadotropin (beta-hCG) is part of the initial evaluation of patients with SCT.]

Question 82

Which branchial cleft cyst occurs on the lower neck, medial to or through the lower sternocleidomastoid?

Answer 82

3rd branchial cleft cyst [UpToDate: Third branchial cleft cysts also are located anterior to the sternocleidomastoid muscle but are typically lower in the neck than a second branchial cleft cyst. These anomalies end in the pharynx at the thyrohyoid membrane or pyriform sinus.]

Question 83

What is the appropriate treatment for Wilms tumor (nephroblastoma)?

Answer 83

Nephrectomy (90% cured) [If venous extension occurs in the renal vein, the tumor can be extracted from the vein. Need to examine the contralateral kidney and look for peritoneal implants. Avoid rupture of tumor with resection, which will increase stage. Actinomycin and vincristine based chemo in all unless stage 1 and \< 500g tumor.] [UpToDate: Multimodal therapy for patients with unilateral Wilms tumor (stages I through IV) includes: * Surgical excision for all patients with resectable tumors * Chemotherapy for all patients except those with very low risk tumors * Radiation therapy as indicated by stage and/or histology Because our institution is a member of the COG group, we treat patients with unilateral Wilms tumor with initial surgical resection followed by chemotherapy. An alternate approach (used by the SIOP group) is to treat patients preoperatively with chemotherapy prior to surgical resection. Patients treated by either approach have excellent and comparable clinical outcomes.]

Question 84

Which condition is characterized by hamartomatous lesions that are comprised of cystic and adenomatous elements arising from tracheal, bronchial, bronchiolar, or alveolar tissue, potentially compromising alveolar growth and development by compressing adjacent normal tissue.

Answer 84

Congenital pulmonary airway malformations (CPAMs), also known as congenital cyxtic adenoid malformation [UpToDate: Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic adenomatoid malformation (CCAM), is a developmental anomaly of the respiratory tract. CPAMs are categorized as types 0 through 4, which are defined pathologically and have different clinical presentations and prognoses. Type 1 CPAMs comprise approximately 70 percent of all CPAMs. Large cysts may be detected on prenatal ultrasound and may cause respiratory distress in the neonate. Smaller cysts may present months or years later as incidental findings on imaging studies or as a focus of recurrent pulmonary infection. Type 1 CPAMs are associated with a slight risk of malignancy. Care must be taken not to misclassify type 4 lesions as type 1, because type 4 lesions have a high malignant potential. Type 4 CPAMs comprise 5 to 10 percent of all CPAMs. Many of these lesions are cystic forms of pleuropulmonary blastoma (PPB), so identification and resection of these lesions is essential. Important clues that suggest this type of CPAM are presentation with pneumothorax, the presence of bilateral or multifocal lung cysts, or a family history of lung cysts or PPB-associated conditions. All infants with a prenatal diagnosis of CPAM should have a chest radiograph in the neonatal period, even if they are asymptomatic and even if the lesion appeared to resolve on serial prenatal ultrasounds. In addition, all infants should have computerized tomography (CT) or magnetic resonance imaging (MRI). The timing of the imaging depends on symptoms and on the results of the initial chest radiograph. CT or MRI should be performed even in infants with normal chest radiographs because plain radiographs often fail to detect CPAM in asymptomatic neonates.

Question 85

Which lobe is most commonly affected in congenital lobar emphysema (CLE)?

Answer 85

Left upper lobe [UpToDate: The different pulmonary lobes are variably affected by CLE. The left upper lobe is affected most often (40-50% of cases). The distribution in right middle, right upper, and lower lobes is 25-35%, 20%, and 2-10%, respectively. CLE affecting multiple lobes is rare.]

Question 86

How is bronchopulmonary sequestration treated?

Answer 86

Lobectomy [UpToDate: Infants with BPS that is causing any respiratory symptoms (respiratory distress or tachypnea) are treated with surgical excision; surgery is curative and is associated with minimal morbidity. The procedure is performed urgently in newborns with significant respiratory distress. Surgical resection is typically performed electively in older children who present with infection. For asymptomatic patients of any age with characteristics that suggest a high risk for developing complications (large lesions occupying \>20 percent of the hemithorax, bilateral or multifocal cysts, or pneumothorax), we suggest surgical resection rather than observation (Grade 2C). For asymptomatic patients without these high-risk characteristics, either elective surgical resection or conservative management with observation are reasonable options and practice varies.]

Question 87

What is the #1 cause of childhood death?

Answer 87

Trauma

Question 88

What is the treatment for an undescended testicle?

Answer 88

Orchiopexy through inguinal incision [If not able to get testicles down then close and wait 6 months and try again. If will not come down, perform division of spermatic vessels.] [UpToDate: Orchiopexy is a well-established surgical procedure for repositioning undescended testes that are palpable. The testis and cord are freed from surrounding attachments, and the testis is manipulated into the scrotum and sutured in place. The procedure is performed through either an inguinal or scrotal incision. Primary orchiopexy is possible if the testis is of normal size and appearance and the testicular vessels are of adequate length. In a 2012 systematic review, the average success rate for primary orchiopexy was 96%, with success defined by scrotal position of the testis. A detailed knowledge of the retroperitoneal anatomy is required to achieve safe and adequate mobilization of the high undescended testis. Thus, orchiopexy is an operation that is best performed by a surgeon with a full-time interest in pediatric urology. Orchiopexy is safe in infants younger than one year. The most significant complication is testicular atrophy (related to ischemic injury secondary to the dissection of the testicular vessels and/or postoperative swelling and inflammation). In a 2012 systematic review, the pooled rate of testicular atrophy following primary orchiopexy was 1.8%. Other potential complications include reascent of the testis (requiring repeat procedure), inguinal hernia, infection, and bleeding. Postoperative management is fairly straightforward. To prevent dislodgement of the testis from the scrotum, straddle toys such as bicycles are avoided for several weeks. Sports activities also are limited in the older child. Examination one to two weeks postoperatively allows assessment of wound healing and testicular location. Repeat examination is performed at least three months postoperatively to assess testicular position and size.]

Question 89

What is the most common general surgery tumor in a child less than 2 years of age vs a child more than 2 years of age?

Answer 89

* \< age 2: Neuroblastoma * \> age 2: Nephroblastoma (Wilms tumor)

Question 90

Which childhood malignancy is derived from neural crest cells and often presents with increased catecholamines, VMA, HVA, and metanephrines (HTN)?

Answer 90

Neuroblastoma [#1 most common solid abdominal malignancy in children. It encases vasculature rather than invading it.] [UpToDate: Neuroblastoma should be considered in the differential diagnosis of children who present with: * Abdominal mass (retroperitoneal or hepatic) * Abdominal pain or constipation * Proptosis * Periorbital ecchymoses ("raccoon eyes") * Horner syndrome (miosis, ptosis, anhidrosis) * Paraspinal mass * Localized back pain, weakness * Scoliosis, bladder dysfunction * Palpable nontender subcutaneous nodules * Opsoclonus myoclonus syndrome * Otherwise unexplained secretory diarrhea In children with the above symptoms or signs and additional supportive evidence for neuroblastoma (eg, adrenal mass on ultrasonography, elevated urinary catecholamines), completion of the evaluation is best performed at a major pediatric cancer center where pediatric oncologists, surgeons, and radiologists familiar with neuroblastoma can be closely involved in the planning and coordination. Definitive diagnosis of neuroblastoma must be made by histologic confirmation or evidence of metastases to bone marrow with concomitant elevation of catecholamines in the urine. The minimal recommended evaluation for primary disease should include computed tomography (CT) or magnetic resonance imaging (MRI) scan of the primary site with three-dimensional measurements, bone imaging preferably with a metaiodobenzylguanidine (MIBG) scan, and bilateral iliac crest bone marrow aspirate and biopsy.]

Question 91

Do congenital inguinal hernias occur more commonly on the right, left, or bilateral?

Answer 91

Right (60% of cases) [30% occur on the left and 10% occur bilaterally.] [UpToDate:The incidence in boys is three to four times higher than in girls, with the right side being affected more commonly in both sexes. In boys, the incidence is highest during the first year of life and peaks during the first month. The right-sided preponderance is related to the later descent of the right testicle and later obliteration of the processus vaginalis. The incidence of bilateral hernias is approximately 10% in full-term and nearly 50% in premature and low-birth-weight infants.]

Question 92

What percent of cases of malrotation occur in the 1st month of life and what percent present by 1 year of age?

Answer 92

* 75% in 1st month * 90% by 1 year of age [Presents as sudden onset of bilious vomiting (Ladd's bands cause duodenal obstruction, coming out from the right retroperitoneum.). Volvulus associated with compromise of the SMA, leading to infarction of the intestine. Malrotation results from failure of normal counterclockwise rotation (270 degrees).] [UpToDate:Rotational anomalies occur as a result of an arrest of normal rotation of the embryonic gut. During the fourth to eighth week of embryonic development, the embryonic coelom, or cavity, cannot accommodate the rapidly expanding gastrointestinal (GI) tract. As a result, the primary intestinal loop buckles into the area of the yolk stalk, which will be the future umbilicus. The axis of this loop is the developing superior mesenteric artery (SMA). As the primary intestinal loop buckles out of the abdomen, it begins the normal rotation of the bowel by twisting 90 degrees counterclockwise. This initial rotation is driven by two factors: The proximal bowel grows faster than the distal bowel, and the rapid growth of the liver. The primary loop continues to grow, and then returns to the abdomen during the 8th to 10th week of gestation. With the return to the abdomen, there is an additional 180 degrees counterclockwise rotation. The overall effect is that the bowel rotates 270 degrees counterclockwise from the original primary loop. Once the bowel has rotated into its final position, fixation to the posterior abdomen occurs. The proximal portion of the bowel is fixed to the retroperitoneum early in gestation (at the ligament of Treitz), whereas fixation of the colon is gradual and usually completed near term.]

Question 93

Which has a worse prognosis: Gastroschisis or Omphalocele?

Answer 93

Omphalocele has worse overall prognosis compared with gastroschisis secondary to congenital anomalies [Malrotation can occur with both gastroschisis and omphalocele.] [UpToDate: Reported survival rates vary and reflect the ability to diagnosis abdominal wall defects prenatally and the decision of many families to proceed with termination of pregnancy when severe or multiple anomalies are present. Neonatal morbidity and mortality rates are directly correlated with the presence or absence of associated anatomic and chromosomal anomalies; thus, the severity of the associated anomalies is closely linked to fetal and neonatal death. The size of the defect can impact prognosis. Although a study that compared long-term outcomes of survivors with minor versus giant defects reported no difference between the two groups in quality of life, repair can be a long and difficult process, involving multiple surgical procedures. Neonates with an extracorporeal liver have a poorer prognosis than those with an intracorporeal liver. A study using a prospectively collected database including almost 1500 infants with omphalocele discharged from 348 neonatal intensive care units in North America from 1997 to 2012 reported the following outcomes: * 60% of births occurred at term and 28% occurred between 33-36 weeks. * 92% of live births survived to hospital discharge. * 9% had pulmonary hypertension and half of these newborn received pulmonary vasodilating drugs. The risk of infant death is as high as 45% in infants with pulmonary hypertension. The incidence of pulmonary hypertension appears to correlate with the size of the defect; it has been reported in 37% of infants with giant omphalocele. * Among survivors, the median length of hospitalization after birth was 17 days.]

Question 94

What is the appropriate treatment for a branchial cleft cyst?

Answer 94

Resection [UpToDate: Recurrent infections of branchial cysts can occur, and a fistula tract to the skin may develop. Recurrent infections may complicate surgical removal, increasing the risk of injury to important structures such as the facial nerve when the parotid is involved. Acute severe infections of third or fourth branchial cleft cysts can cause pharyngeal edema and airway and swallowing problems. Management of branchial cleft cysts begins with controlling infection, if present. Once the infection has resolved, the mass is usually excised to prevent future problems.]

Question 95

Which 2 tumor markers are elevated in patients with a teratoma?

Answer 95

* Alpha-fetoprotein (AFP) * Beta-HCG [More commonly sacrococcygeal in neonates; ovarian in adolescents.] [UpToDate: Teratomas are the most common type of germ cell tumor. Most, but not all, teratomas are benign. The designation teratoma refers to a neoplasm that differentiates toward somatic-type cell populations (typically including cell populations that would normally derive from ectoderm, endoderm, and mesoderm) that can be typical of either adult or embryonic development. The component tissues in a teratoma range from immature to well differentiated and are foreign to the anatomic site in which they are found. Teratomas are divided into four categories: mature (cystic or solid, benign), immature (malignant), malignant due to a component of another somatic malignant neoplasm, and monodermal or highly specialized.]

Question 96

What is the most common cause of neonatal jaundice requiring surgery?

Answer 96

Biliary atresia [Progressive jaundice persisting \> 2 weeks after birth suggests atresia. Can involve either the extrahepatic or intrahepatic biliary tree or both. Get cholangitis, continued cirrhosis, and eventual hepatic failure.] [UpToDate: Biliary atresia (BA) is a progressive, idiopathic, fibro-obliterative disease of the extrahepatic biliary tree that presents with biliary obstruction exclusively in the neonatal period. Although the overall incidence is low (about one in 10,000 to 20,000 live births), BA is the most common cause of neonatal jaundice for which surgery is indicated and the most common indication for liver transplantation in children. Most infants with biliary atresia (BA) are born at full term, have a normal birth weight and initially thrive and seem healthy. Signs/symptoms include: * Jaundice is the first sign of BA. Initially, the jaundice may be seen only in the sclerae. The onset of jaundice occurs any time from birth up to eight weeks of age, and it is highly unlikely to appear later. * Some infants have acholic stools. Acholic stools often go unrecognized because the stools are pale but not white and the stool color can vary on a daily basis. In a study from Japan that included more than 300,000 newborn infants, stool color cards completed by the parents had a sensitivity of 76.5% and specificity of 99.9%, respectively, for identifying infants with biliary atresia. * Most infants have dark urine because of bilirubin excretion into the urine. This often is not recognized by parents, who may not realize that infant urine should not stain a diaper yellow. * If the jaundice has gone unnoticed and the child's disease has progressed, there may be a firm, enlarged liver and splenomegaly.]

Question 97

At what age should an undescended testicle be intervened upon?

Answer 97

Before 2 years of age [Higher risk of testicular cancer in these children. Cancer risk stays the same even if testicles brought into the scrotum. If undescended bilaterally, get chromosomal studies. If you cannot feel the testes in the inguinal canal, you need to get an MRI to confirm their presence.] [UpToDate: Most testes that are undescended at birth complete their descent within the first three to four months of life. Spontaneous descent is rare after six months of age. The growth of unilateral undescended testes may be impaired compared with the normally descended contralateral testes, whether the undescended testes descend spontaneously or are surgically corrected. Treatment before one year of age may be associated with partial catch-up growth. Surgical treatment of undescended testes is recommended as soon as possible after six months of age for congenitally undescended testes and definitely should be completed before the child is two years old. In children with testicular ascent later in childhood, surgery generally should be performed within six months of identification. Spontaneous descent rarely, if ever, occurs after six months of age. Treatment before two years (ideally before one year) of age is associated with improved testicular growth and fertility potential. In a randomized trial, 149 boys with unilateral palpable undescended testis were assigned to orchiopexy at nine months or three years of age. At 12, 24, 36, and 48 months of age, testes in the nine-month group were larger and had greater increase in size compared with baseline than testes in the three-year group. No significant growth was noted in the three-year group. Testicular biopsies demonstrated a decline in the number of germ and Sertoli cells between nine months and three years. Treatment of undescended testes before puberty also may reduce the risk of testicular cancer, permit earlier detection of testicular masses, and prevent testicular torsion.]

Question 98

What is the most likely lead point in an adult presenting with intussusception?

Answer 98

Malignant lead point (ie colon cancer in cecum) [OR for resection.] [UpToDate: Intestinal intussusception is rare in adults, accounting for 1-5% of mechanical bowel obstructions. In adults, intussusception is typically due to pathologic lead point within the bowel, which is malignant in over half of cases. The lead point is pulled forward by normal peristalsis, telescoping or prolapsing the affected segment of bowel (intussusceptum) into another segment of bowel (intussuscipiens). An increased incidence of intussusception has been reported in patients with acquired immune deficiency syndrome (AIDS). This is due to the high incidence of infectious and neoplastic conditions of the bowel in AIDS patients, such as lymphoid hyperplasia, Kaposi's sarcoma, and non-Hodgkin's lymphoma. Intussusception can be classified by etiology (benign lesion [eg, polyps, Meckel’s diverticulum], malignant lesion, or idiopathic) or by location as entero-enteric, which is limited to the small bowel; ileo-colic with prolapse of the terminal ileum into the ascending colon; and colo-colic, which is limited to the large bowel. In adults, intermittent abdominal pain is the most common presentation; however, patients can also present with symptoms consistent with intermittent partial bowel obstruction with nausea, vomiting, melena, weight loss, fever, and constipation. Plain abdominal films may show the typical features of distal small bowel obstruction. The diagnosis is often made on abdominal CT. The distended loop of bowel appears thickened because it represents two layers of bowel. A “target sign” may be seen on the sagittal view of the abdominal CT, while on axial or coronal view, the intussusception will appear as a sausage-shaped mass.]

Question 99

What percent of hepatoblastomas are associated with elevated AFP?

Answer 99

90% [Associated with fractures and precocious puberty (from beta-HCG release). Better prognosis than hepatocellular carcinoma.] [UpToDate: Hepatoblastomas commonly occur as a single mass in up to 85 percent of cases and more often in the right lobe of the liver. Because of rapid growth, death can occur from rupture and hemorrhage. Serum alpha-fetoprotein (AFP) levels are markedly elevated. Sexual precocity may be present due to the synthesis of ectopic gonadotropin. In children, hepatoblastoma must be differentiated primarily from HCC that arises in metabolic diseases and some chronic liver diseases (eg, hereditary tyrosinemia, Alagille syndrome and other familial cholestatic syndromes, neurofibromatosis, ataxia-telangiectasia, Fanconi anemia). Cirrhosis and other risks factors are absent in patients with hepatoblastoma.]

Question 100

What is the treatment for congenital vascular malformations?

Answer 100

Embolization (may be sufficient on its own) and/or resection [Surgery for hemorrhage, ischemia, CHF, nonbleeding ulcers, functional impairment, or limb-length discrepancy.]

Question 101

Meconium ileus occurs in what percent of children with cystic fibrosis?

Answer 101

10% [Causes distal ileal obstruction, abdominal distension, bilious vomiting, and distended loops of bowel. Need sweat chloride test or PCR for Cl channel defect. Abdominal x-ray shows dilated loops of small bowel without air-fluid levels (because the meconium is too thick to separate from the bowel wall); can have ground glass or soapsuds appearance. Can cause perforation, leading to meconium pseudocyst or free perforation, requires laparotomy.] [UpToDate: Meconium ileus (MI) is a disorder of the neonate caused by the obstruction of the small intestines at the level of the terminal ileum with inspissated meconium. The widespread use of prenatal carrier testing and prenatal detection of MI by ultrasound enables clinicians to counsel patients and plan proactive management of this complication of CF. Approximately 10% of patients with CF present as neonates with MI; in most cases these patients have CF transmembrane conductance regulator gene (CFTR) mutations associated with inadequate CFTR production or folding ("severe" genotypes). Conversely, most series suggest that 80-90% of infants with MI have CF, although a few series report higher proportions of non-CF MI, particularly in low birthweight infants.]

Question 102

What is the treatment for imperforate anus?

Answer 102

* High imperforate anus: Colostomy with later anal reconstruction with posterior sagittal anoplasty * Low imperforate anus: Sagittal anoplasty (pull anus down into sphincter mechanism). No colostomy required [High: above levators; meconium in urine or vagina (fistula to bladder/vagina/prostatic urethra). Low: Below levators; meconium to perineal skin. Both need postop anal dilatation to avoid stricture. These patients are prone to constipation. More common in males. Check for associated renal, cardiac, and vertebral (VACTERL) anomalies.] [UpToDate: Imperforate anus may be an isolated finding or part of a syndrome such as VACTERL (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities) association. Abnormalities of the rectum and anus are thought to be due to arrest of the caudal descent of the urorectal septum to the cloacal membrane. The resulting malformations range from isolated imperforate anus to persistent cloaca. These malformations are classified as “high” supralevator lesions, which end above the levator sling and are typically associated with fistulas, and “low” infralevator lesions, which end below the levator sling and are not associated with fistulas. Anal atresia may be associated with rectovesical fistula. In these cases, urine can mix with meconium resulting in a dilated fluid filled rectum with intraluminal calcifications, which is easily identified by ultrasound. On MRI, the rectum may be fluid filled with high signal on T2w. When calcifications are noted, it is important to determine if they are intraluminal or extraluminal. Intraluminal calcifications suggest a rectovesical fistula. Extraluminal may be secondary to meconium peritonitis. Echogenic bowel with meconium peritonitis may be related to cystic fibrosis.]

Question 103

What presents in a newborn with spitting up feeds, excessive drooling, and respiratory symptoms with feeding?

Answer 103

Tracheoesophageal fistula [Type C is most common. Type A is second most common.]

Question 104

What is the appropriate treatment of an infantile hemagioma?

Answer 104

Observation (Most resolve spontaneously by age 7 or 8) [Appear at or shortly after birth. Rapid growth during first 6-12 months of life, then begin to involute. If lesion has uncontrollable growth, impairs function (eyelid or ear canal), or is persistent after age 8 y/o: Can treat with oral steroids. Laser or surgical resection can be attempted if steroids fail.] [UpToDate: The approach to the treatment and the choice of treatment modality for infantile hemangiomas should be individualized depending upon the size of the lesion(s), location, presence of complications, potential for scarring or disfigurement, the age of the patient, the rate of growth or involution at the time of evaluation, the potential risk(s) and benefits of treatment, the availability of the various modalities, and the experience of the treating clinician. Treatment is usually required for complicated hemangiomas that may interfere with a vital structure or function and for lesions at increased risk of ulceration, scarring, and disfigurement. The goals of treatment include prevention or reversal of life- or function-threatening complications; prevention or minimization of disfigurement, bleeding, infection, and pain; and minimization of psychosocial distress for the patient and family. We suggest active nonintervention for uncomplicated hemangiomas that are not disfiguring (Grade 2C). Active nonintervention requires regular monitoring of the clinical course and attention to the psychosocial implications for the child and family. We recommend oral propranolol as the first-line agent for the treatment of complicated hemangiomas with the potential to impair function or cause disfigurement (eg, periorbital hemangiomas) (Grade 1A). Treatment is started with 0.5 to 1 mg/kg per day and then gradually increased to the target dose of 2 mg/kg per day. Systemic glucocorticoids, vincristine, and interferon alpha are alternative agents for aggressive hemangiomas but are rarely needed since the advent of propranolol. Children with periorbital hemangiomas should be evaluated by an ophthalmologist who is experienced in the treatment of hemangiomas. We suggest oral propranolol in addition to meticulous wound care and appropriate analgesia for the treatment of ulcerated hemangiomas that may cause permanent disfigurement, interfere with daily life activities, or do not respond to wound care measures (Grade 2C).]

Question 105

What intrauterine event causes intestinal atresias to occur?

Answer 105

Intrauterine vascular accidents [Symptoms include bilious emesis, distention; Most do not pass meconium. Must get a rectal biopsy to rule out Hirschsprung's before surgery.] [UpToDate: Duodenal atresia: During early gestation (weeks six and seven), portions of the intestinal tract become occluded as the endodermal epithelium proliferates. Patency is restored as recanalization occurs during weeks eight to ten. Duodenal atresia is thought to result from failure of the bowel to recanalize during this period. Jejunal and ileal atresia: Atresia here is typically thought to result from vascular disruption leading to ischemic necrosis of the fetal intestine. Because the fetal bowel is sterile, the necrotic tissue is resorbed, leaving blind proximal and distal ends, often with a gap in the mesentery. This type of atresia has been reproduced in experimental animals by ligation of mesenteric blood vessels. Causes of the vascular disruption in the human fetus include segmental or midgut volvulus, intussusception, internal hernia, and interruption of the segmental mesenteric blood supply. In a fetus with gastroschisis, compression of the gut may occur at the level of the opening in the abdominal wall, causing an atresia to form. In a fetus with cystic fibrosis, an atresia may develop after segmental volvulus of the jejunum or ileum. Colonic atresia: The colon is a less frequent site of atresia, comprising 2-15 percent of intestinal atresias. The mechanism is unknown, but most authorities believe it is the same as for small bowel atresia. Colonic atresia may occur in combination with Hirschsprung disease.]

Question 106

What is the appropriate treatment for a teratoma?

Answer 106

Excision [UpToDate: Treatment of mature mediastinal teratomas is surgical excision, and this is almost always curative. Resection generally is through a median sternotomy or posterolateral thoracotomy, depending upon the location of the tumor, although thoracoscopic resection is occasionally possible. Subtotal resection with relief of compressive symptoms is performed if benign teratomas cannot be excised completely without endangering surrounding vital structures. If only subtotal resection is possible, it is not clear that additional treatment with chemotherapy or radiotherapy offers any benefit. Mature teratomas are relatively insensitive to both chemotherapy and radiation therapy (RT). Ovarian cystectomy is suggested in order to make a definitive diagnosis, preserve ovarian tissue, and avoid potential problems such as torsion, rupture, or development of malignant components. For women who have completed childbearing, salpingo-oophorectomy is also acceptable treatment. Benign cystic teratomas do not recur if surgically resected.]

Question 107

What is the most common tumor of the pediatric larnyx?

Answer 107

Laryngeal papillomatosis [Frequently involutes after puberty. Can treat with endoscopic removal or laser but frequently comes back. Thought to be caused from HPV in the mother during passage through the birth canal.] [UpToDate: Recurrent respiratory papillomatosis (RRP) is the most common benign laryngeal tumor in children. RRP is typically diagnosed between the ages of two and three years, and most children are diagnosed before five years of age. RRP is thought to be caused by acquisition of human papillomavirus (HPV) during passage through the birth canal of an infected mother. HPV6 and HPV11 are most commonly involved, although HPV16 has been rarely observed and may be associated with an increased risk of malignant degeneration. Risk factors for RRP include being the firstborn child, vaginal delivery, and having a teenage mother who has genital condylomata. In one large retrospective cohort study, infants born to mothers with a history of genital warts were 231 times more likely (95% CI 135-396) to develop respiratory papillomatosis than those born to mothers without such a history. However, among infants born to women with such a history, the risk of RRP was less than 1%. HPV infects squamous mucosa, both naturally occurring and because of metaplasia of respiratory epithelium. Metaplasia of the respiratory epithelium can occur as a result of chronic environmental exposure or repeated trauma. Symptoms of RRP include hoarseness, breathiness, occasional respiratory distress, intermittent respiratory obstruction, and aphonia. Physical examination typically reveals multiple verrucous, polypoid growths overlying the true vocal folds, false vocal folds, subglottic region, and trachea. In a small number of young children who have aggressive lesions, tracheotomy may be required for airway control. However, tracheotomy may be associated with an increased risk of recurrence and development of lower airway papillomas. In children who have a less aggressive course, the treatment of RRP usually involves microlaryngeal surgery to debulk the lesions. Most children with RRP require multiple surgical treatments before puberty (when RRP typically regresses), particularly if they were diagnosed before the age of three years. In one review of 399 children with juvenile-onset RRP, the mean number of surgical procedures per child was 4.4 per year (range less than 1-19). The time interval between surgical procedures depends upon the individual patient's severity. This author prefers the use of the KTP laser to remove lesions of the laryngotracheal airway.]

Question 108

What is the most common cause of duodenal obstruction in newborns (\<1 week old)?

Answer 108

Duodenal atresia [Usually occurs distal to the ampulla of Vater and causes bilious vomiting, feeding intolerance. Associated with polyhydramnios in mother and cardiac, renal, and other GI anomalies in newborn.] [UpToDate: Infants with duodenal atresia or stenosis typically have gastric distension and vomiting that is often but not always bilious. Affected infants may pass meconium. Duodenal atresia is an isolated finding in one-third to one-half of cases. However, it is often associated with other malformations, including gastrointestinal (biliary atresia, agenesis of the gall bladder), cardiac, renal, and vertebral anomalies. As an example, in a series of newborns undergoing surgery for gastrointestinal malformations, echocardiography detected congenital heart disease in six of 20 infants with duodenal atresia. Approximately 24 to 28 percent of newborns with duodenal atresia or stenosis have Down syndrome. Conversely, approximately 2.5 percent of patients with Down syndrome have duodenal atresia or stenosis.]

Question 109

Which branchial cleft cyst is the most common and appears on the anterior border of the mid-sternocleidomastoid muscle?

Answer 109

2nd branchial cleft cyst [Goes through carotid bifurcation into tonsillar pillar.] [UpToDate: Second branchial cleft cysts are the most common type of branchial cleft anomaly. They are usually located just inferior to the angle of the mandible and anterior to the sternocleidomastoid muscle. The sinus tract of a second branchial cleft cyst will travel through the deep structures of the neck and open into the tonsillar fossa. The location and cystic nature of second branchial cleft cysts may lead to difficulty in distinguishing these from cystic lymph node metastasis of human papilloma virus (HPV)-related oropharynx squamous cell carcinoma.]

Question 110

What arises from anomalous budding of the foregut during development, and although relatively rare, is the most common cystic lesion of the mediastinum?

Answer 110

Bronchogenic cyst [Usually posterior to the carina. They are extra-pumonary cysts formed from bronchial tissue and cartilage wall. They usually present with a mediastinal mass filled with milky liquid. They can compress adjacent structures or become infected. They have malignant potential.] [UpToDate: Bronchogenic cysts appear on chest radiograph as round water-density masses that may have air-fluid levels associated with previous or current infection. CT typically shows sharply marginated cystic mediastinal masses of soft tissue or water attenuation. Lesions that appear solid on CT usually can be characterized as cystic by MRI. The radiographic appearance of bronchogenic cysts and other developmental anomalies of the lung is discussed in detail separately. Gross pathologic examination demonstrates unilocular cysts that are filled with thick, clear fluid and do not communicate with the tracheobronchial tree. On histologic examination, the cyst is lined by respiratory epithelium with occasional foci of squamous metaplasia; the wall resembles that of larger airways and contains smooth muscle, glands, and cartilage. The presence of cartilage plates is the most reliable diagnostic criterion.]

Question 111

How are bronchogenic cysts treated?

Answer 111

Cyst resection [UpToDate: The management of a bronchogenic cyst consists of surgical excision by partial or total lobectomy. This procedure is curative. Controversy exists regarding the need for resection when patients are asymptomatic. We recommend surgery in all cases because of the likelihood of eventual development of symptoms and the potential for serious illness. In addition, malignant degeneration may occur with this disorder, as in other congenital cystic anomalies. Although surgical excision is typically straightforward, operative complications have been reported. The prenatal ultrasound identification of large cysts compressing cardiovascular structures warrants in utero thoracentesis to prevent fetal hydrops.]

Question 112

What is the most common cause of painless lower GI bleeding in children?

Answer 112

Meckel's diverticulum [UpToDate: Meckel's diverticulum results from incomplete obliteration of the omphalomesenteric duct. It is usually asymptomatic, but may cause painless rectal bleeding, which may be chronic and insidious, or acute and massive. The bleeding is often caused by mucosal ulceration of adjacent small bowel tissue due to production of acid by ectopic gastric tissue within the diverticulum. Other complications associated with a Meckel's diverticulum are obstruction, perforation, diverticulitis, and intussusception. Sixty percent of pediatric patients having complications from a Meckel's diverticulum are younger than two years of age. The "rule of twos" is used to describe the epidemiology of Meckel's diverticulum: it occurs in two percent of the population with a male-to-female ratio of 2:1, is found within two feet of the ileocecal valve, involves two types of tissue (gastric and intestinal epithelium), and is two inches long. Approximately 2% of individuals with a Meckel's diverticulum develop a complication over the course of their lives. There is probably no familial predisposition for Meckel's diverticulum, although a few cases of occurrence within the same family have been reported. The diagnosis is made by a Meckel scan. The scan consists of the intravenous administration of 99m technetium pertechnetate, which has an affinity for gastric mucosa, followed by scintigraphy to identify areas of ectopic gastric mucosa. The accuracy of a Meckel scan is improved by administration of histamine type 2 receptor antagonists (H2 blockers) for 24-48 hours before the test. A symptomatic Meckel's diverticulum should be resected. An asymptomatic Meckel's diverticulum discovered incidentally at laparotomy usually also is resected in children. However, whether such asymptomatic lesions should be resected in adults is controversial because of the low incidence of complications in older patients who have never had symptoms.]

Question 113

What is the mortality rate of necrotizing enterocolitis?

Answer 113

10% [UpToDate: Prognosis of NEC has improved with earlier recognition and treatment, with survival rates of about 70-80% of affected infants. In addition, approximately one-half of the survivors are normal. Long-term sequelae include gastrointestinal complications (eg, short bowel syndrome, intestinal strictures, and increased frequency of bowel movements with loose stools) and impairment of growth and neurodevelopmental outcome.]

Question 114

What is the appropriate treatment for meconium ileus?

Answer 114

Gastrograffin enema (effective 80% of the time) [Can also make the diagnosis and potentially treat the patient. Can also use N-acetylcysteine enema. If surgery is required, manual decompression and create a vent for N-acetylcysteine antegrade enemas.] [UpToDate: Nonoperative management – If simple MI is confirmed by the diagnostic enema, it is usually managed by administration of hyperosmolar enema (typically diluted sodium meglumine diatrizoate, Gastrografin), closely monitored by fluoroscopy. The hyperosmolar contrast often breaks up the meconium mass and clears the obstruction. This approach is successful in 20-40% of neonates with simple MI. Complications occur in 2-10% of these procedures and include intestinal perforation and fluid shifts with hypotension and shock. Historical series reported higher success rates (60-80%), but with higher complication rates as compared with more recent series. The higher rates of success and complications in historical series may both depend on use of higher instillation pressures and multiple attempts, and the experience of the radiologist. Operative management – Surgical approaches are used for complicated MI and for some cases of simple MI that do not clear with nonoperative intervention. Operative procedures include simple enterotomy with lavage, double enterostomy, and/or resection of dilated, perforated, or atretic bowel, with diversion ileostomy. Patients with CF and ileostomies are at increased risk of sodium loss, and careful attention should be paid to sodium requirements and replacement. Total body sodium depletion, which can occur in the face of normal serum sodium, should be considered in infants with ileostomies who are not gaining weight.]

Question 115

What is the most common malignant liver tumor in children?

Answer 115

Hepatoblastoma [Can be pedunculated. Vascular invasion is common.] [UpToDate: Hepatoblastoma is the most common primary hepatic malignancy in early childhood. The majority of hepatoblastomas occur in the first two years of life and rarely in children older than five years. This is in contrast to hepatocellular carcinoma (HCC), which rarely occurs in children younger than five years old. The incidence of hepatoblastoma in boys is twice that in girls. Syndromes with an increased incidence of hepatoblastoma include Beckwith Wiedmann syndrome, trisomy 18, trisomy 21, Acardia syndrome, Li-Fraumeni syndrome, Goldenhar syndrome (a type of craniofacial microsomia), type 1a glycogen storage disease (von Gierke’s disease), and familial adenomatous polyposis (FAP). Hepatoblastomas commonly occur as a single mass in up to 85% of cases and more often in the right lobe of the liver. Because of rapid growth, death can occur from rupture and hemorrhage. Serum alpha-fetoprotein (AFP) levels are markedly elevated. Sexual precocity may be present due to the synthesis of ectopic gonadotropin. Hepatoblastomas arise from primitive cells that have the potential to differentiate along several lines. As such, hepatoblastoma mimics the developing fetal and embryonal liver, and is composed of a variety of cell types, giving rise to a morphologically complex tumor, which may include fetal and/or embryonal hepatocytes and heterologous tissues including cartilage, bone, striated muscle fibers, and squamous epithelium.]

Question 116

What presents as projectile vomiting in a newborn at 3 to 12 weeks of age?

Answer 116

Pyloric stenosis [More common in firstborn males. Often an olives-sized mass can be palpated in region of stomach. Patients get hypochloremic, hypokalemic metabolic alkalosis.] [UpToDate: The classic presentation of infantile hypertrophic pyloric stenosis (IHPS) is the three- to six-week-old infant who develops immediate postprandial vomiting that is nonbilious and forceful (often described as “projectile” vomiting). The infant then demands to be re-fed soon afterwards (a "hungry vomiter"). These characteristics were seen in a series of 132 infants who were diagnosed with IHPS in the 1970s, in which 91% presented with projectile vomiting after feedings. The majority (83%) were boys, and 31% were firstborn. In another review of infants diagnosed between 1957 and 1969, the mean age in which the infants began vomiting was 22 days. IHPS rarely occurs after 12 weeks of age. Patients were classically described as being emaciated and dehydrated with a palpable "olive-like" mass at the lateral edge of the rectus abdominis muscle in the right upper quadrant of the abdomen. The frequency of palpation of the "olive" typically was quite high (up to 92 percent) in a report from 1975, but has been noted to be less common in subsequent reports. Laboratory evaluation classically showed a hypochloremic, metabolic alkalosis due to the loss of large amounts of gastric hydrochloric acid, the severity of which depended upon the duration of symptoms prior to initial evaluation. Similarly, hypokalemia is common in infants who have been vomiting for longer than three weeks but typically is not seen in those with a more recent onset of symptoms.]

Question 117

What is the best indicator of shock in a child?

Answer 117

Tachycardia [Neonate \> 150, Over a year old \> 120]

Question 118

What volume bolus should be administered to a child during trauma?

Answer 118

20cc/kg x 2, then give 10cc/kg of blood [Want urine output \>2-4cc/kg/hr. Children \< 6 months old have only 25% of the GFR capacity of adults (poor concentrating ability)]

Question 119

What is the treatment for congenital diaphragmatic hernia?

Answer 119

High-frequency ventilation; inhaled nitric oxide; may need ECMO * Stabilize these patients before operating * Need to reduce the bowel and repair defect +/- mesh (abdominal approach) * Look for visceral anomalies (run the bowel) [Overall survival is 50%.] [UpToDate: The treatment of CDH in the neonate has changed since the first reports of surgical repair in the 1940s. Initially, CDH was treated as a surgical emergency with early surgical intervention. In the mid-1980s, it was recognized that major determinants of mortality included pulmonary hypoplasia and pulmonary hypertension. As a result, the emphasis shifted from early surgical intervention to preoperative care directed towards optimal management of these two associated conditions, followed by surgical repair. This approach has improved survival to its current reported rates of 70% to 92%, from the previous 50% associated with early surgical correction.]

Question 120

What is the appropriate treatment for hepatoblastoma?

Answer 120

Resection is optimal; otherwise doxorubicin and cisplatin based chemotherapy [Survival is primarily related to resectability. Fetal histology has best prognosis.] [UpToDate: Hepatoblastoma consists of malignant liver cells at various stages of maturation and a variable mesenchymal component. The epithelial component always predominates and consists of two types of cells: "embryonal"-type cells, which are small, basophilic, darkly stained with uniform, hyperchromatic nuclei and scanty cytoplasm, arranged in sheets, ribbons, rosettes, acini, or tubules; and "fetal"-type cells, resembling hepatocytes with central round to oval nuclei and abundant granular or clear cytoplasm depending on the amount of glycogen or fat. The cells are larger, eosinophilic, and lighter stained than the embryonal-type cells and arranged in trabeculae or plates. They are separated by sinusoids and may form bile canaliculi. The variation of darker and lighter-stained cells is characteristic of hepatoblastoma. Extramedullary hematopoiesis is often present in the sinusoids. When the biopsy specimen is small and contains only fetal-type cells, the distinction from well-differentiated HCC may be difficult. The presence of a mesenchymal component, most commonly osteoid tissue and rarely cartilage, rhabdomyoblasts, or neural elements, rules out HCC. AFP is almost always demonstrable in the cytoplasm of the epithelial cell component by immunohistochemical staining.]

Question 121

What volume of maintenance fluid should be administered to a child?

Answer 121

* 4cc/kg/hr for 1st 10 kg * 2cc/kg/hr for 2nd 10 kg * 1cc/kg/hr for everything after that

Question 122

What is characterized as a congenital malformation resulting from lymph accumulation in the jugular lymphatic sacs due to obstruction of the lymphatic system in the fetal neck and is usually found in the lateral cervical regions of the neck?

Answer 122

Cystic Hygroma [Treatment is resection}

Question 123

What is the weight cut off for low birth weight and the gestational age cut off for prematurity?

Answer 123

* Low birth weight \<2,500 g * Premature \< 37 weeks

Question 124

What is the most common type of anterior mediastinal mass in children?

Answer 124

Germ cell tumor [UpToDate: The anterior compartment lies between the back of the sternum and the anterior aspect of the great vessels and pericardium. The anterior compartment normally contains the thymus, internal mammary arteries, lymph nodes, connective tissue, and fat. The most common lesions occurring in the anterior mediastinum are often referred to as the “terrible T’s”: thymoma, teratoma/germ cell tumor, (terrible) lymphoma, and thyroid tissue.]

Question 125

What is the treatment for congenital umbilical hernia?

Answer 125

Surgery if not closed by age 5, if patient has a VP shunt, or if complicated by incarceration [UpToDate: Because the natural course of the umbilical ring is eventual closure, most umbilical hernias will spontaneously resolve. In general, asymptomatic children with an umbilical ring that continues to decrease can be observed. Surgical intervention is required only in a minority of patients. Incarcerated umbilical hernia in children is an absolute indication for surgical repair to avoid strangulation. Children with large, proboscoid (trunk-like) hernias without any decrease in the size of the umbilical ring defect over the first two years of life, generally require surgery, because their hernias will fail to close spontaneously. Other relative indications for surgical repair include defects that cease decreasing in size, are symptomatic, or create significant behavioral problems.]