Pretest_14_PediatricSurgery Flashcards
What is the etiology of imperforate anus?
Failure of descent of the urorectal septum
Imperforate anus can be high or low. When high, it ends where? When low, where?
High: prostatic urethra or vagina
Low: perineal fistula
In females, a high imperforate anus exists with a (closed/open) cloaca.
Open cloaca (when rectum, vagina, and urethra coexist with a single perineal orifice)
There is a greater chance of ultimate fetal continence in (high/low) inperforate anus
low
Hirschsprung disease is congenital absence of ganglion cells in the ________________ (which part of the colon)
rectum or rectosigmoid colon
Hirschspurng disease is definitively diagnosed by
rectal biopsy
What are the findings of Hirschsprung disease on barium enema?
a distal narrow segment of bowel with markedly distended colon proximally
What is the treatment of Hirschsprung disease?
It is initially treated with a colostomy with definitive repair delayed until nutritional status is adequate and the chronically dilated bowel has returned to normal size
Which midline masses in children close around the age of 4?
umbilical hernias; do not need to be repaired
What is a urachal duct? How is it treated?
incomplete closure of embryonal tracts from the bladder. Excision of the tract and closure of the bladder (same for omphalomesenteric ducts and ileum)
What is the difference between gastrochisis and omphalocele? How are they treated?
Gastrochisis and omphalocele = projection of abdominal contents through anterior wall.
Gastrochisis = to right of umbilical ring with intact umbilical cord, no associated congenital anomalies
Omphalocele = through umbilical ring; peritoneum on inside, amnion on outside; karyotype abnormalities and other cogenital malformations 30%
Both require emergent surgical treatment to immediate or staged reduction and abdominal wall closure
What is the VACTERL syndrome?
Vertebral anomalies (lumbosacral) Anal atresia Cardiac defect (VSD) TracheoEsophageal fistula (esophageal atresia) Renal abnomalies (hydronephrosis) Limb defects (radial dysplasia)
What is the basis of jejunoileal atresia?
a mesenteric vascular accident during intrauterine growth
How do you treat obstruction secondary to an annular pancreas?
Duodenoduedenostomy
How does intussusception occur appear on barium enema?
coiled spring
Where in the bowel is intussusception most common?
ileocolic
What is the appropriate initial treatment of intussusception if bloody mucus, peritonitis, or systemic toxicity have not developed?
Hydrostatic reduction by barium enema
T/F: Intussusception is frequently preceded by a GI viral illness
True
This condition is clinically indistinguishable form appendicitis:
an inflamed Meckel diverticulum
A Meckel diverticula is a remnant of the ___________ duct
vitelline
Where are Meckel diverticula usually located? What type of tissue can they contain?
60 cm proximal to the ileocecal valve. Are usually antimesenteric and may contain gastric and pancreatic or only pancreatic tissue
T/F: Hemorrhage or obstruction is a more common presentation of Meckel diverticula than inflammation
True
T/F: Meckel diverticula discovered incidentally are usually not removed.
True! Potential of complications is low, unless has thin neck, palpable heterotopic tissue, or nodularity (all prone to obstruction) or if patient has appendicitis (will have scar in RLQ)
A baby coughing and choking during the first oral feeding along with excessive salivation and a maternal history of polyhydramnios indicates…
esophageal atresia
If gas is present in the GI tract along with an inability to pass an NGT into the stomach, think…
esophageal atresia with tracheoesophageal fistula
What is the next step in evaluating an infant with EA and TEF?
other VACTERL abnormalities! (vertebral anomalies, anal atresia, cardiac defects, TE fistula, renal abnormalities, limb abnormalities)
What is a silastic silo?
allows for gradual reduction of a giant omphalocele for the viscera into the abdominal cavity over several days
The radiographic hallmark of necrotizing enterocolitis is ____________. The single most important predisposing factor is ___________.
radiographic hallmark: pneumatosis intestinalis
most important predisposing factor: prematurity
What is the treatment of NEC?
Medical management successful in 50% of cases: bowel rest, NG tube decompression, fluid-resuscitation, broad spectrum antibiotics. Surgery for patients with decompensation, abdominal wall cellulitis, falling WBC or platelets, intestinal perforation, persistent fixed loop on abdominal films
Meconium ileus is the earliest sign of which disorder?
cystic fibrosis
What is the treatment of meconium ileus?
Initially = water-soluble contrast enema; if enema fails to resolve, operative management (enterotomy for warm water irrigation to manipulate meconium into distal colon or remove through enterotomy)
Infant’s AXR revealing dilated loops of small bowel, absence of air-fluid levels, and a mass of thick tarklike material in right side of abdomen mixed with gas to give a ground-glass appearance:
meconium ileus
T/F: Pyloric stenosis is more common in females than males.
False! More prevalent in male infants at a ratio of 4:1
Why is it important to correct metabolic alkalosis in a patient with pyloric stenosis prior to surgery?
The patient might have compensatory respiratory acidosis following the surgery, leading to postoperative apnea
What is the surgical treatment of pyloric stenosis?
Pyloromyotomy
What is biliary atresia? What are the gross findings? What is the treatment?
Progressive obliteration of the extrahepatic and intrahepatic bile ducts, eventually leading to irreversible hepatic fibrosis if not corrected (with exploratory lap to confirm fibrotic biliary remnants and absent proximal and distal duct patency) Procedure is Kasai hepatoportoenterostomy!
What is the etiology of congenital diaphragmatic hernia? Where are the hernias located (antero/postero/medio/lateral)
Failure of the embryonic diaphragm to fuse. Located posteriolaterally
An anteromedial hernia through the diaphragm is called
hernia of Morgagni (immediately adjacent to xiphoid process)
T/F: A diaphragmatic hernia can lead to pulmonary dysplasia.
True: abdominal organs are space occupying and prevent maturation of the lung. The pulmonary hypoplasia is what results in the primary pulmonary hypertension, not the abdominal organs pressing on the lungs. Should stabilize the respiratory distress (with ECMO or medically) prior to repair
Congenital coarctation of the aorta occurs just (distal/proximal) to the subclavian artery, in the area of the
distal (left); ligamentum arteriosum
Coarctation of the aorta is associated with what classic X ray finding?
notching of the ribs
Coarctation of the aorta is associated with what other cardiac defects?
VSDs, aortic stenosis
T/F: Surgery is not recommended for VSD unless the shunt is leading to pulmonary HTN or the patient is aged 5 or older
True
If biliary atresia is suspected (ie by ultrasound findings, jaundice), what is the next step?
Expeditious ex lap to confirm the diagnosis with demonstration of fibrotic biliary remnants and absent proximal and distal bile duct patency.
The bowel loops in gastrochissis are generally matted together from
chemical peritonitis
Which uses sterile dressing as a cover and which plastic?
omphalocele vs gastrochisis
sterile dressing = omphalocele
plastic = gastrochisis
In anal atresia, supralevator fistulas (above the puborectalis sling) are more common in (boys/girls).
Infralevator fistulas are more common in (boys/girls).
supralevator more common in boys! Connection between rectal pouch and urethra.
Infralevator more common in girls
An infant with a fistula between the rectal pouch and urinary tract leads to which electrolyte abnormality?
Hyperchloremia (chloride excreted by urine is readily absorbed by the colonic mucosa, leading to excretion of bicarb and acidosis).
A biopsy showing Hirschsprung disease will show which plexus: Auerbach or Meissner?
Only Auerbach. (has both SNS and PNS fibers).
Meissner only has PNS fibers.
Even though the PNS fibers are absent, the sympathetic fibers in Auerbach plexus will still pick up the stain
Hirschsprung disease is caused by teh failure of development of
parasympathetic ganglia in the colonic submucosa, without which the muscularis layers cannot retract
What other than being premature is a risk factor for NEC?
formula feeding
The INITIAL evaluation of an infant suspected to have GER is
barium swallow (manometry and pH studies are hard to perform, and endoscopy is better for long standing GERD)
T/F: Most patients with pectus excavatum do not have any comorbidities related to the deformity.
True! Ultimately some may develop restrictive pulmonary disease or easy fatigability.
What is an advantage of the Nuss procedure to elevate the sternum in pectus excavatum vs traditional costal cartilage resection?
The Nuss procedure avoids impairment in chest wall growth
What are other abnormalities that can be associated with Wilms tumor?
aniridia, hypospadias, hemihypertrophy
