Peds GI disease Flashcards
Tracheo-esophageal fistula pathogenesis
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)
Tracheo-esophageal fistula presentation
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
Tracheo-esophageal fistula treatment
surgery
Infantile hypertrophic pyloric stenosis pathogenesis
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.
Infantile hypertrophic pyloric stenosis presentation
•non-bilious, projectile vomiting (70%) associated with upper abdominal mass (60-80%); usually presents around 3 wks of life
Infantile hypertrophic pyloric stenosis diagnosis and surgery
Diagnosis: H+P; ultrasound. Treatment: surgery – pyloromyotomy
Meckel Diverticulum pathogenesis
•abnormal remnant of vitelline (omphalomesenteric) duct (connection between yolk sac and intestine). Results in an outpouching from terminal ileum
Meckel Diverticulum presentation
Usually asymptomatic. Obstruction 35% (most common in neonates), Bleeding 40% (usually older children), Inflammation 17%
Meckel Diverticulum diagnosis and treatment
Diagnosis: Technetium-99 scan (detects gastric mucosa) or/and other imaging (US/CT). Treatment: surgical resection
Meckel Diverticulum histology
contains heterotopic gastric or pancreatic tissue in 50%
Omphalocele pathogenesis
•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
Omphalocele diagnosis and treatment
Diagnosis: often prenatal (ultrasound). Treatment: surgery – return of contents to abdominal cavity and abdominal wall closure (may need to be staged/gradual procedure)
Gastroschisis
paraumbilical defect in the abdominal wall leading to protrusion of bowels.
Compare omphalocele to gastroschisis
Gastroschisis has no amniotic covering and no associated malformations, while omphalocele has both of these. Both have protrustion of bowels from abdomen
Intestinal malrotation pathogenesis
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.
Intestinal malrotation presentation
Most are asympotomatic, but midgut volvulus and obstruction (bilious vomiting) can occur
Intestinal malrotation diagnosis and treatment
Diagnosis: H+P; imaging; surgical exploration. Treatment: surgery
Gastrointestinal duplications pathogenesis
•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
Gastrointestinal duplications presentation
may be found incidental, may cause bowel obstruction.
Gastrointestinal duplications diagnosis and treatment
Diagnosis: H+P; imaging; surgical exploration. Treatment: surgery
Intestinal atresia pathogenesis
Complete failure of bowel development resulting in blind ending, presumed vascular (ischemic) etiology. Duodenal atresia most common, and many also have Down Syndrome
Intestinal atresia presentation
•polyhydramnios, obstructive symptoms (bilious vomiting)
Intestinal atresia associations
generally occur along with other malformations as part of a malformation syndrome or in the setting of cystic fibrosis
Intestinal Atresia vs stenosis
Stenosis refers to congenital narrowing of the bowel whereas atresia refers to complete failure of development causing a blind ending
Imperforate anus/rectal agenesis pathogenesis
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
· Understand the underlying developmental abnormality in Hirschsprung Disease
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
Hirschsprung disease presentation
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.
Hirschsprung disease treatment
surgical resection of the abnormal segment of bowel
Understand the predisposing factors and proposed pathogenesis of Necrotizing Enterocolitis
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.
Necrotizing enterocolitis presentation
•feeding intolerance, abdominal distention, bloody stools
Necrotizing enterocolitis treatment and complications
treatment: bowel rest, antibiotics, resection. Complications: bowel strictures, short bowel syndrome
Compare and contrast allergic and reflux esophagitis: etiology, pH probe
Reflux esophagitis: incompetent gastroesophageal sphincter/ hiatal hernia, pH probe positive. Allergic esophagitis: immunologic reaction to dietary allergen, pH probe negative
Compare and contrast allergic and reflux esophagitis histology
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
Compare treatment of reflux and allergic esophagitis
reflux: acid blockade. Allergic: dietary modification, steroids.
