Peds GI disease

Question 1

Tracheo-esophageal fistula pathogenesis

Answer 1

failure of normal separation of intestinal and respiratory tracts; The distal esophagus is attached to the trachea. Most cases also have esophageal atresia (esophagus ends in blind pouch)

Question 2

Tracheo-esophageal fistula presentation

Answer 2

Prenatal: polyhydramnios (too much amniotic fluid). Postnatal: choking with feeds, inability to swallow oral secretions; H+P, passage of feeding tube into upper GI tract

Question 3

Tracheo-esophageal fistula treatment

Answer 3

surgery

Question 4

Infantile hypertrophic pyloric stenosis pathogenesis

Answer 4

hypertrophy and hyperplasia of the smooth muscle in the gastric wall at the level of the pylorus that leads to narrowing of the antrum that can cause near complete obstruction. The proximal stomach is typically secondarily dilated.

Question 5

Infantile hypertrophic pyloric stenosis presentation

Answer 5

•non-bilious, projectile vomiting (70%) associated with upper abdominal mass (60-80%); usually presents around 3 wks of life

Question 6

Infantile hypertrophic pyloric stenosis diagnosis and surgery

Answer 6

Diagnosis: H+P; ultrasound. Treatment: surgery – pyloromyotomy

Question 7

Meckel Diverticulum pathogenesis

Answer 7

•abnormal remnant of vitelline (omphalomesenteric) duct (connection between yolk sac and intestine). Results in an outpouching from terminal ileum

Question 8

Meckel Diverticulum presentation

Answer 8

Usually asymptomatic. Obstruction 35% (most common in neonates), Bleeding 40% (usually older children), Inflammation 17%

Question 9

Meckel Diverticulum diagnosis and treatment

Answer 9

Diagnosis: Technetium-99 scan (detects gastric mucosa) or/and other imaging (US/CT). Treatment: surgical resection

Question 10

Meckel Diverticulum histology

Answer 10

contains heterotopic gastric or pancreatic tissue in 50%

Question 11

Omphalocele pathogenesis

Answer 11

•failure of intestines to return to abdomen following normal physiologic herniation at wks 6-10 of development; peritoneal and amniotic covering. Also associated with other congenital anomalies

Question 12

Omphalocele diagnosis and treatment

Answer 12

Diagnosis: often prenatal (ultrasound). Treatment: surgery – return of contents to abdominal cavity and abdominal wall closure (may need to be staged/gradual procedure)

Question 13

Gastroschisis

Answer 13

paraumbilical defect in the abdominal wall leading to protrusion of bowels.

Question 14

Compare omphalocele to gastroschisis

Answer 14

Gastroschisis has no amniotic covering and no associated malformations, while omphalocele has both of these. Both have protrustion of bowels from abdomen

Question 15

Intestinal malrotation pathogenesis

Answer 15

abnormal rotation and fixation of large intestine, typically occurs as intestines are returning to abdominal cavity after 10 weeks gestation. Can occur in isolation or complicate omphalocele, gastroschisis, etc.

Question 16

Intestinal malrotation presentation

Answer 16

Most are asympotomatic, but midgut volvulus and obstruction (bilious vomiting) can occur

Question 17

Intestinal malrotation diagnosis and treatment

Answer 17

Diagnosis: H+P; imaging; surgical exploration. Treatment: surgery

Question 18

Gastrointestinal duplications pathogenesis

Answer 18

•Saccular (cystic) or tubular structures containing all layers of normal bowel wall and gastrointestinal lining, which may or may not communicate with bowel. Most commonly involves small intestine

Question 19

Gastrointestinal duplications presentation

Answer 19

may be found incidental, may cause bowel obstruction.

Question 20

Gastrointestinal duplications diagnosis and treatment

Answer 20

Diagnosis: H+P; imaging; surgical exploration. Treatment: surgery

Question 21

Intestinal atresia pathogenesis

Answer 21

Complete failure of bowel development resulting in blind ending, presumed vascular (ischemic) etiology. Duodenal atresia most common, and many also have Down Syndrome

Question 22

Intestinal atresia presentation

Answer 22

•polyhydramnios, obstructive symptoms (bilious vomiting)

Question 23

Intestinal atresia associations

Answer 23

generally occur along with other malformations as part of a malformation syndrome or in the setting of cystic fibrosis

Question 24

Intestinal Atresia vs stenosis

Answer 24

Stenosis refers to congenital narrowing of the bowel whereas atresia refers to complete failure of development causing a blind ending

Question 25

Imperforate anus/rectal agenesis pathogenesis

Answer 25

spectrum of severity ranging from a thin membrane of tissue covering the anus to the worst disease which is complete agenesis of rectum. up to 50% associated with other anomalies such as fistula formation

Question 26

· Understand the underlying developmental abnormality in Hirschsprung Disease

Answer 26

defect of enteric nervous system (ENS) development resulting in absence of ganglion cells. Usually casued by mutations in RET receptor or ligand that control development of nervous plexi of colon OR mutations in endothelin 3 and endothelin receptor genes leading to failure of bowel nerve plexi (Auerback and Meissner) to form in segment of bowel

Question 27

Hirschsprung disease presentation

Answer 27

aka congenital megacolon- massive dilatation of the intestinal lumen with normal innervation and constriction of bowel lacking ganglion cells. Detected when children fail to pass meconium after birth.

Question 28

Hirschsprung disease treatment

Answer 28

surgical resection of the abnormal segment of bowel

Question 29

Understand the predisposing factors and proposed pathogenesis of Necrotizing Enterocolitis

Answer 29

Abnormal circulation (patent ductus arteriosis) is risk factor. Associated with hypoxemia - ischemic damage to bowel wall leads to invasion by organisms, formation of gas gangrene (pneumatosis intestinalis), perforation and peritonitis.

Question 30

Necrotizing enterocolitis presentation

Answer 30

•feeding intolerance, abdominal distention, bloody stools

Question 31

Necrotizing enterocolitis treatment and complications

Answer 31

treatment: bowel rest, antibiotics, resection. Complications: bowel strictures, short bowel syndrome

Question 32

Compare and contrast allergic and reflux esophagitis: etiology, pH probe

Answer 32

Reflux esophagitis: incompetent gastroesophageal sphincter/ hiatal hernia, pH probe positive. Allergic esophagitis: immunologic reaction to dietary allergen, pH probe negative

Question 33

Compare and contrast allergic and reflux esophagitis histology

Answer 33

reflux: Mild intraepithelial eosinophilic infiltrate, Reactive epithelial changes, Predominantly distal esophageal involvement. Allergic: Marked intraepithelial eosinophilic infiltrate, Reactive epithelial changes, Frequent submucosal inflammation with fibrosis, Distal and proximal esophageal involvement

Question 34

Compare treatment of reflux and allergic esophagitis

Answer 34

reflux: acid blockade. Allergic: dietary modification, steroids.