26. Congenital defects of the bowel Flashcards
What is the key presentation that can indicate malrotation (medical emergency)?
Bilious emesis (yellow/green)
When in devo does the gut extend out of the abdomen, and how does it rotate?
4th-8th weeks
Twists 90 degrees CCW while hernitated, and an additional 180 decrees CCW when back in the abdomen
What fixes the SI at the duodenal jejunum?
Ligament of Treitz
What are bands that cross the duodenum and can cause obstruction with midgut volvulus?
Ladd’s bands
What will be seen on abdominal x-ray with an NGT in when there is midgut volvulus?
Gasless abdomen
Where should the ligament of Treitz be located on abdominal X-ray?
To the left of the patient’s spine at the duodenojejunal junction
What is the Ladd’s procedure?
Treatment for midgut volvulus
- untwisting of the bowel, removal of the Ladd’s bands, widening of the mesentery
- Put the small bowel on the right and colon on the left
- Appendectomy to prevent future confusion with appendicitis
What is the classic sign for duodenal atresia on a prenatal US?
Double bubble sign, polyhydraminos
What is the pathogenesis of duodenal atresia?
Failure of recanalization–duodenum passes though solid phase but should have reopening of the lumen between weeks 8 and 10
Embryological insult during the recanalization period (weeks 8-10) can result in: (3)
- Duodenal stenosis
- Duodenal web
- Duodenal atresia
What causes the double bubble sign?
Dilated stomach and proximal duodenum resulting from obstruction
What are the two things that should indicate duodenal atresia within a few hours of birth?
Vomiting that is clear or bilious
Double bubble sign on X-ray
What are the two possibilities for level of obstruction with duodenal atresia and which one is more common?
Pre or post-ampullary
80% are post-ampullary, resulting in bilious emesis
What genetic defects/congenital abnormalities is duodenal atresia associated with?
Trisomy 21 ***
Cardiac
Genitourinary
Anorectal
What are the steps for tx of duodenal atresia?
NG tube
R/o other causes with physical exam and echo
Duodenoduodenostomy: anastomosis of proximal to distal duodenum
What is the pathogenesis of jejunoileal atresia?
In utero vascular disruption leads to ischemic necrosis of the fetal intestine
Necrotic intestine is reabsorbed, leaving blind proximal and distal ends, often with a gap in the mesentery
What are risk factors for development of jejunoileal atresia?
- Inherited thrombophilia leading to spontaneous thormbosis
- Maternal use of vasoconstrictive medications may disrupt the mesenteric blood flow: pseudoephedrine, cocaine, and nicotine
- Rare familial inheritance
What causes the low birth weight and prematurity in jejunoileal atresia?
Polyhydraminos
Congenital anomalies associated with jejunoileal atresia?
Unlike duodenal atresia, not commonly associated with extraintestinal anomalies
Treatment of jejunoileal atresia
Surgery: explartory lapartomy, primary anastomosis
**long term issues depending on the intestinal length
What can be used for a child that is hard to get an IV in?
IO line (intraosseous)
What is a congenital disease in intestinal inntervation? More common in what gender?
Hirschsprung’s disease
Males
Hischsprung’s disease is associated with what congenital disorder?
Trisomy 21 (downs syndrome)
What is the MC genetic mutation to be associated with Hirschsprung’s disease?
RET mutations: RET is a receptor tyrosine kinase that transduces differentiation signals in many developing tissues, including neural crest cells
