Pediatrics: Gastrointestinal, Luminal Flashcards
Frontal chest radiograph with an NG tube stopped in the upper neck…
Think tracheoesophageal fistula/esophageal atresia
What is the most common subtype of esophageal atresia/tracheoesophageal fistula?
N-type fistula (85%)
Note: This is a blind ending upper esophagus with the lower esophagus communicating with the trachea.
H-type esophageal atresia
When the entire esophagus is present, but there is also a tracheoesophageal fistula
How do you diagnose esophageal atresia/tracheoesophageal fistula?
Fluoroscopic swallow study
Esophageal atresia/tracheoesophageal fistula is associated with…
VACTERL:
- Vertebral anomalies
- Anus, imperforate
- Cardiac anomalies
- Tracheoesophageal fistula/Esophageal atresia
- Renal anomalies
- Limb anomalies
Excessive air in the stomach in a newborn…
Think tracheoesophageal fistula (classically H-type, but also seen with N-type)
What are the major subtypes of tracheoesophageal fistula?
- N-type (blind ending upper esophagus; lower esophagus connects to the trachea)
- Esophageal atresia (blind-ending upper esophagus without any connection to the trachea)
- H-type (full esophagus with additional tracheoesophageal fistula)
No air in the stomach of a newborn…
Think esophageal atresia
What imaging finding should be mentioned (if present) prior to repair of a tracheoesophageal fistula?
Right aortic arch (changes surgical approach)
VACTERL
A collection of congenital anomalies that are highly associated:
- Vertebral anomalies (37%)
- Anus, imperforate (63%)
- Cardiac anomalies (77%)
- Tracheoesophageal fistula/Esophageal atresia (40%)
- Renal anomalies (72%)
- Limb anomalies (58%)
Diagnosis of VACTERL
When 3 or more of the VACTERL anomalies are found in a pt
Which of the VACTERL anomalies are the most common to find?
- Cardiac (77%)
- Renal (72%)
Major complication of esophageal atresia repair
Focal anastomotic stricture (occurs in 30% of cases)
A coin is present at the level of the thoracic inlet and appears linear (not round) on a frontal chest radiograph. Where is it?
Trachea, the flexible posterior membrane causes coins to orient in the sagittal plane
Note: If it appears round on frontal radiograph, it is more likely in the esophagus.
Why are pennies minted after 1982 a more problematic foreign body than other coins?
Pennies minted after 1982 are mostly made of zinc, which can cause gastric ulcerations when exposed to stomach acid
Note: Pennies minted before 1982 were made of copper, which is relatively safe.
Management of ingested AA or AAA batteries
Serial plain films and extraction if they stay in the stomach for more than 2 days
Management of ingested disc battery
Emergency removal if in esophagus (within 2 hours)
Urgent/emergent removal from stomach (within 12 hours)
Name the vascular impression
Pulmonary sling (the only variant that goes between the esophagus and the trachea)
Name the vascular impression
Double aortic arch
Name the vascular impression
Innominate artery compression
Name the vascular impression
Left arch with aberrant right subclavian
OR
Right arch with aberrant left subclavian
Pulmonary sling has a high risk of…
Tracheal stenosis
Note: The pulmonary sling is when the left pulmonary artery arises from the right pulmonary artery and then runs between the trachea and esophagus.
Treatment of pulmonary sling
Surgical repositioning of the malpositioned left pulmonary artery (to avoid tracheal stenosis)
What is the most common symptomatic vascular ring?
Double aortic arch
Diverticulum of Kommerell
A pouch like aneurysmal dilatation of the origin of an aberrant right subclavian artery
Dysphagia lusoria
Dysphagia secondary to an aberrant right subclavian artery
Differential for high bowel obstruction in the neonate
- Midgut volvulus/malrotation
- Duodenal atresia
- Duodenal web
- Annular pancreas
- Jejunal atresia
Differential for low bowel obstruction in the neonate
- Hirschprung disease
- Meconium plug syndrome
- Ileal atresia
- Meconium ileus
- Anal atresia/colonic atresia
Neonatal radiograph demonstrates absent bowel gas except for a single bubble in the left upper quadrant…
Think gastric (astral or pyloric) atresia
Neonatal radiograph demonstrates absent bowel gas except for a double bubble in the left upper quadrant…
Duodenal atresia
Note: The “double bubble” sign without any distal gas is highly specific for duodenal atresia. Any distal gas excludes duodenal atresia.
Jejunal atresias are associated with…
Other atresias (e.g. colonic atresia)
Note: Jejunal atresia is usually due to a vascular insult during development that causes multiple atresias.
Neonatal radiograph demonstrates prominent gastric bubble with some distal air in a newborn with bilious vomiting…
Suspicious for midgut volvulus, recommend emergent upper GI study
Neonatal radiograph demonstrates a “double bubble” in the left upper quadrant with scant gas distally…
Think duodenal web, duodenal stenosis, or midgut volvulus and recommend an upper GI series
Note: Any distal gas, even small volumes, excludes duodenal atresia.
Neonatal radiograph demonstrates diffusely dilated loops of bowel…
Think low obstruction (e.g. ileum or large bowel) and recommend a contrast enema (if normal, then get upper GI to exclude atypical midgut volvulus)
Third trimester ultrasound demonstrates “double bubble” appearance in fetal left upper quadrant…
Duodenal atresia
Neonatal upper GI
Corkscrew duodenum, diagnostic of midgut volvulus (surgical emergency)
What should you look for on a neonatal upper GI series?
- Does contrast opacify the entire duodenum (if not, think duodenal obstruction)
- Does the duodenum pass the midline to the left hemiabdomen (if not, think malrotation/volvulus)
- Is there a corkscrew appearance of the duodenum (midgut volvulus)
Malrotation is associated with a high risk of what complications?
Midgut volvulus and internal hernias
Note: They can also get intermittent duodenal obstruction due to compression from Ladd’s bands.
Malrotation is associated with…
- Heterodoxy syndrome
- Omphaloceles
On US or CT, the SMA is to the right of the SMV…
Malrotation
1 month old with non bilious vomiting…
Think hypertrophic pyloric stenosis and recommend an ultrasound
Infant with bilious vomiting…
Think midgut volvulus and recommend emergent upper GI series
Ladd’s bands
Fibrous bands attaching the cecum to the abdominal wall that can cause intermittent obstruction in the setting of malrotation
Ladd’s procedure
Treatment for malrotation (surgical disruption of the Ladd’s bands that predispose to duodenal obstruction and midgut volvulus)
Preduodenal portal vein
An anatomic variant where the portal vein sits anterior to the 2nd part of the duodenum
Note: This is associated with duodenal obstruction 50% of the time secondary to Ladd’s bands, annular pancreas, or other causes of duodenal obstruction.
Causes of partial duodenal obstruction in a neonate
Extrinsic compression (Ladd’s bands in malrotation, annular pancreas)
Intrinsic narrowing (duodenal web, duodenal stenosis)
When does hypertrophic pyloric stenosis occur?
2-12 weeks of age (peak 3-6 weeks)
Note: NOT before 2 weeks and not after 3 months.
Ultrasound criteria for hypertrophic pyloric stenosis
4 mm single wall thickness and length of at least 14 mm
What is the main differential diagnosis for hypertrophic pyloric stenosis on ultrasound?
Pylorospasm (which should relax during the exam; true hypertrophy will not relax)
What is a major cause of false negatives on US for hypertrophic pyloric stenosis?
Gastric over distention (which can displace the gastric antrum/pylorus)
Organoaxial gastric volvulus
The greater curvature flips over the lesser curvature (rotation around the long axis)
Note: This type is mainly seen in older pts with paraesophageal hernias.
Mesenteroaxial gastric volvulus
Twisting of the mesentery so that the gastric antrum flips up over the GE junction (rotation around the short axis)
Note: This type is more common in kids and requires surgical correction.
What are the types of gastric volvulus?
- Organoaxial (usually older pts)
- Mesenteroaxial (usually kids)
Which type of gastric volvulus requires surgical correction?
Mesenteroaxial (twisting of the mesentery can lead to ischemia)
Inability to pass an NG tube, severe epigastric pain, and retching without vomiting…
Borchardt triad, suggestive of gastric volvulus
Do you get bilious or non-bilious vomiting with a duodenal web?
Bilious
Note: The web is distal to the ampulla of Vater.
Duodenal webs are associated with…
- Malrotation
- Downs syndrome
Duodenal obstruction with pancreatic tissue surrounding the duodenum on CT…
Annular pancreas
What are the four major categories of findings on a neonatal barium enema?
- Normal
- Short microcolon
- Long microcolon
- Caliber change
Short microcolon on barium enema…
Think colonic atresia
Long microcolon on barium enema…
- Meconium ileus (contrast reaches ileal loops)
- Distal ileal atresia (no contrast reaches ileal loops)
- Total colonic aganglionosis (rare variant of Hirschsprung disease that affects the entire colon)
Note: Long microcolon is when the entire colon opacifies, but is narrow caliber.
Meconium ileus indicates that the pt has…
Cystic fibrosis (thickened meconium causes the microcolon)
Note: Do not confuse meconium ileus (affects entire colon) with meconium plug syndrome (only affects a distal portion of the colon and is not associated with CF).
Treatment for meconium ileus
Enema (diagnostic and therapeutic)
Treatment for distal ileal atresia
Surgery
Small left colon syndrome
AKA meconium plug syndrome is a transient functional colonic obstruction due to a stuck piece of meconium
Note: Diagnosis and treatment is with an enema.
Risk factors for meconium plug syndrom
- Maternal diabetes
- Mom received magnesium sulfate for eclampsia
Note: Meconium plug syndrome is NOT associated with cystic fibrosis (meconium ileus is).
Epidemiology of Hirschsprung disease
4:1 more common in boys
Hirschprung disease is associated with…
Downs syndrome (10% of cases)
Diagnosis of Hirschsprung disease
Rectal biopsy (showing lack of ganglion cells)
Barium enema demonstrates a recto-sigmoid ratio < 1
Hirschsprung disease
Note: Is the rectum is smaller than the sigmoid, its Hirschsprung.
Barium enema demonstrates a “sawtooth” pattern of the rectum…
Hirschsprung disease
Note: The sawtooth pattern is due to bowel spasm.
Newborn fails to pass stool for > 48 hours after birth and has forceful passage of stool after rectal exam…
Hirschsprung disease
Barium enema demonstrates a long microcolon and also narrowing of the terminal ileum…
Think total colonic aganglionosis (a rare variant of Hirschsprung disease that involves the entire colon and can also involve the distal ileum)
Infant radiograph demonstrates a large eggshell calcified mass in the mid abdomen…
Think meconium peritonitis (sterile peritoneal reaction to an in-utero bowel perforation)
Note: Usually the perforation seals itself off before birth.
Meconium peritonitis
A sterile peritoneal reaction to an in-utero bowel perforation that results in a large mass-like calcification on radiographs
Note: This is often a complication of bowel atresia or meconium ileus.
Peripherally calcifies mass in an infant, suggestive of calcified meconium peritonitis
What should you recommend if you identify an imperforate anus?
Screening ultrasound for tethered spinal cord (these are highly associated)
Imperforate anus is associated with…
- VACTERL anomalies
- Tethered spinal cord
What is a common complication of an imperforate anus?
Enteric fistula formation to the genitourinary tract
What are the major causes of bowel obstruction in over children?
AAIIMM
- Appendicitis
- Adhesions
- Inguinal hernia
- Intussusception
- Midgut volvulus
- Meckels
What is the most common cause of bowel obstruction in children over age 4?
Appendicitis
Which type of inguinal hernia is most common in children?
Indirect inguinal hernias (lateral to the inferior epigastric artery)
What is the most common cause of bowel obstruction in a male 1 month to 1 year old?
Inguinal hernia
What is the normal age range for obstructive intussusception?
Between 3 months and 3 years (90%)
Note: Before 3 months or after 3 years, you should be suspicious about a pathological lead point.
Intussusceptum vs intussuscipiens
The intussusceptum is the proximal bowel that herniates into the lumen of the distal bowel (the intussuscipiens)
Note: In the target sign, the intussuscipiens would be on the outside.
How can you tell between a problematic intussusception and a transient one?
Problematic intussusceptions tend to be larger than 2.5 cm from outer wall to outer wall, usually enterocolic (small bowel-large bowel)
Transient intussusceptions tend to involve only the small bowel (small bowel-small bowel) and are often less than 2.0 cm in diameter
What are common causes of lead points that can cause intussusception?
- Vasculitis (e.g. IgA vasculitis/Henoch-Schonlein purpura)
- Meckle diverticulum
- Enteric duplication cysts
Contraindications to nonoperative reduction of intussusception
- Pneumoperitoneum (check plain film for free air)
- Peritonitis (based on exam)
Is recurrence common following nonoperative reduction of intussusception?
Yes (10% of cases), usually within 72 hours
What is the success rate of pneumatic nonoperative reduction of intussusception?
80-90%
Note: Success rate is lower for pts with IgA vasculitis/Henoch Schonlein purpura.
What is the major risk of nonoperative reduction of intussusception?
Bowel perforation (0.5% of cases)
Why is air used more often than barium for nonoperative reduction of intussusception?
Air causes less peritonitis than barium
Pressure should not exceed ______ during nonoperative reduction of intussusception
120 mmHg
Nest step: nonoperative reduction of intussusception complicated by bowel perforation with development of tension pneumoperitoneum…
Emergent needle decompression
A Meckels diverticulum is a persistent piece of the…
Omphalomesenteric duct
Where are Meckels diverticula located?
Distal ileum (2 feet from the ileocecal valve)
Note: Rule of 2’s.
Rule of 2’s for Meckels diverticula
- 2% of the population
- 2 feet from the IC valve
- 2 inches long
- 2 types of heterotypic mucosa (gastric and pancreatic)
- Usually symptomatic by age 2
Meckel’s scan
A Tc-Pertechnetate nuclear imaging study that visualizes heterotypic gastric mucosa within a Meckels diverticulum
Which Meckel’s diverticula tend to bleed?
Those with heterotypic gastric mucosa
Clinical presentation of Meckel’s diverticulum
Kid with GI bleeding (usually due to heterotypic gastric mucosa in the diverticulum)
Complications of Meckel’s diverticula
- GI bleed
- Meckel’s diverticulitis
- Intussusception (usually the diverticulum will be inverted within the bowel lumen)
- Bowel obstruction
Gastroscisis
Extra-abdominal evisceration of neonatal bowel through a paraumbilical wall defect without a surrounding membrane
Omphalocele
Herniation of neonatal bowel through a midline abdominal wall defect at the base of the umbilical cord with a surrounding membrane (peritoneum)
Gastroschisis always occurs on the…
Right side
Gastroschisis is associated with…
Not much (unlike omphaloceles)
Note: Some association with intestinal atresias.
What specific lab finding is seen in gastroschisis?
Elevated maternal serum AFP (more elevated than in omphalocele)
Is prognosis better with gastroscisis or omphalocele?
Prognosis is better with gastroscisis (due to the syndromes associated with omphalocele)
Major complication of gastroschisis repair
Bad gastroesophageal reflux
Omphalocele is associated with…
- Trisomy 18 (most common associated chromosomal anomaly)
- Cardiac anomalies (50%)
- GI anomalies
- CNS anomalies
- GU anomalies
- Turners syndrome
- Klinefelters
- Beckwith-Wiedemann
- Pentalogy of Cantrell
- Umbilical cord cysts (allantoic cysts)
Pentalogy of Cantrell
- Omphalocele
- Ectopia Cordis (abnormal location of heart)
- Diaphragmatic defect
- Pericardial defect or sternal cleft)
- Cardiovascular malformations
Neonate with bowel herniated through a ventral wall defect that pushes the umbilicus to the left…
Gastroschisis
Note: Omphaloceles have bowel herniating through the umbilicus (you wouldn’t identify a normal umbilicus for omphaloceles).
Which has a midline defect: gastroschisis or omphalocele?
Omphalocele (the defect in gastroschisis is always to the right of midline)
Kid had a bicycle accident and banged against his handlebars…
Think duodenal hematoma
Common causes of duodenal hematoma
- Bicycle handlebar accident
- Child abuse
- Endoscopy
What is the most common location for a duodenal hematoma?
D3
Duodenal hematoma and retroperitoneal gas…
Bowel perforation
Prenatal ultrasound demonstrates a cyst in the fetal abdomen…
- enteric duplication cyst (if it has gut signature)
- Mental cyst (if it does not have gut signature)
In 30% of cases, enteric duplications cysts are associated with…
Vertebral anomalies
What is the most common location for an enteric duplication cyst?
Ileum (40%)
Enteric duplication cyst
A developmental anomaly (failure to canalize) of the GI tract that may or may not communicate with a bowel lumen
Complications of enteric duplication cysts
In utero bowel obstruction/perforation
Gut signature
The alternating hyperechoic and hypo echoic layers that identify a viscus as bowel
Distal intestinal obstruction syndrome
Bowel obstruction in an older child (around 20s) with cystic fibrosis due to poor adherence with pancreatic enzymes resulting in thickened stool in the ileum/ascending colon
Pts with cystic fibrosis who don’t take their pancreatic enzymes may end up with…
Distal intestinal obstruction syndrome (bowel obstruction due to thickened stool in cystic fibrosis)
Cluster of large lymph nodes in the right lower quadrant without any other abnormalities…
Think mesenteric adenitis (diagnosis of exclusion)
Necrotizing enterocolitis
Life-threatening bowel inflammation due to immature bowel allowing fecal pathogens to translocate to the peritoneal cavity
What is the age range for necrotizing enterocolitis?
90% occur within the first 10 days of life (mostly in premature infants)
Risk factors for necrotizing enterocolitis
- Prematurity
- Low birth weight
- Cardiac problems (NEC can even happen in full term infants with heart problems)
- History of perinatal asphyxia
- Hirschsprung kids (usually occurs later, around 1 month of age)
Classic imaging findings of necrotizing enterocolitis
- Pneumatosis/portal venous gas
- Focally dilated bowel (especially in the right lower quadrant)
- Edematous small bowel loops (separated by a lot of space and no valvular conniventes)
- Unchanging bowel gas pattern
