GI System Clinical Topics

Question 1

Esophageal Atresia

Answer 1

blind ended esophagus due to abnormal development of laryngotracheal tube; results in polyhydramnios -> umbilical prolapse into vagina or rupture of amniotic membrane

Question 2

Pyloric stenosis

Answer 2

hypertrophic pyloric sphincter; symptoms are projectile vomiting and electrolyte imbalance (stomach acid loss); 2-6 weeks after birth; multifactorial inheritance w/ male predominance

Question 3

Duodenal atresia or stenosis

Answer 3

insufficient re-canalization of the duodenum at week 8; more likely in Down syndrome

Question 4

Biliary atresia

Answer 4

incomplete connection of bile duct to bile canaliculi; symptom is direct hyperbilirubinemia (glucuronic bilirubin)

Question 5

Annular pancreas

Answer 5

superior pancreatic bud forms anteriorly to the duodenum (instead of posterior) -> constriction of the duodenum

Question 6

omphalocele

Answer 6

persistent umbilical hernia; common in many syndromes, not common otherwise

Question 7

umbilical hernia

Answer 7

herniation after the usual retraction; incarceration of abdominal contents is rare, usually just made up of connective tissue

Question 8

gastroschisis

Answer 8

protrusion of the abdominal contents through the abdominal wall usually due to vascularization; minimal genetic predisposition

Question 9

malrotation

Answer 9

rotation of less than 270 degrees usually resulting in a volvulus = twisting of the small intestine around the superior mesenteric artery

Question 10

nonrotation

Answer 10

no secondary midgut rotation -> small intestinal contents entirely on the right side and the large intestine is on the left

Question 11

ileal (Meckel) diverticulum

Answer 11

persistent omphaloenteric duct (2-4%) may develop ulcers or bleeding in later life

Question 12

Aganglionic megacolon (Hirschsprung disease)

Answer 12

descending colon stenosis caused by incomplete innervation of the smooth peristaltic muscles; male predominant, multifactorial disease (up to 10 genes involved)

Question 13

Membranous anal atresia

Answer 13

persistent anal membrane; will look blue due to meconium

Question 14

Anorectal agenesis

Answer 14

defects resulting from faulty development of the urorectal septum; characterized as “high” or “low” can include fistulas at any level; symptoms of severe agensis is distended abdomen; less severe is ribbon stool