Congenital Abnormalities Flashcards
What should be done upon discovery of a congenital anomaly in the GI system?
search for anomalies else where as they will frequently be present
VACTERL
Vertebral anomolies, Anorectal malformation, Cardiac defects, Tracheoesophageal fistula, Renal anomalies, Limb deformities
What are atresias and fistulas?
Atresia:
-incomplete development of a portion of the gut tube; a portion remains noncanalized, ending in a blind pouch
Fistula:
- abnormal, patent connection of one portion of the gut tube to some other space/cavity
- most common connections include the esophagus to trachea and bowel to bowel, bladder, or even the skin (opening externally)
What are the most common forms of GI atresia/fistula?
Esophageal (most common site of fistula):
- EA with distal TEF (87%; type C); upper esophagus ends blindly while lower esophagus forms fistula with trachea
- isolated EA (8%; type A); both upper and lower esophagus end in blind pouches
- isolated TEF (4%; type E); both upper and lower esophagus form fistula with trachea (looks like letter H -> H-type) can be asymptomatic
Bowel (most common site of atresia):
-imperforate anus
How do esophageal atresias/fistulas present?
regurgitation if fed in both
Atresia:
-excess secretions/foaming at the mouth
Fistula of proximal esophagus:
- coughing and hypoxia
- aspiration -> and pneumonia
- isolated TEF/H-type can be asymptomatic
What is a congenital diaphragmatic hernia?
incomplete formation/closure of thoracic diaphragm -> abdominal contents herniate into pleural cavity
What is an omphalocele and gastroschisis?
Omphalcele:
-ventral, umbilical herniation of abdominal contents enclosed in a membranous sac
Gastroschisis:
-ventral, paraumbilical herniation of abdominal contents w/ no membranous sac
What is ectopia and how does it present in the GI tract?
certain GI tissues located outside of their normal location
ectopic gastric mucosa (most common):
- esophagus (most common site) -> dysphagia, esophagitis, Barrett
- in the colon -> ulceration w/ occult bleeding
ectopic pancreatic tissue:
- cause inflammation -> damage surrounding tissue
- esophagus or stomach (can appear like cancer)
- if in pylorus -> obstruction
What is a Meckel diverticulum? (appearance/location/epi)
What is special about it (2)?
incomplete obliteration of the viteline duct (connection of yolk sac and alimentary tube; normally obliterated at 6th week)
Rules of 2:
- located in the ileum, 2 feet proximal to the ileocecal valve
- ~2 inches long
- 2% of population
- 4%(2x2) of cases are eversymptomatic
- most commonly presents under the age of 2
- 2:1 male predominance
Special features:
- It is a true diverticulum (contains all layers of the intestinal wall)
- may contain ectopic gastric or pancreatic tissue
How might Meckel diverticulum present?
What complications may occur?
- acid secretion from ectopic gastric tissue -> ulceration -> GI bleed
- appendicitis-like abdominal pain
Complications:
- hemorrhage
- bowel obstruction (intussuseception or volvulus)
- perforation
What is pyloric stenosis?
(epidemiology)
congenital hypertrophy of the pyloric valve
Epi:
- 0.1-0.3% (1 in 300-900) of the population
- 3-5X male predominance
What is the etiology of pyloric stenosis?
What factors are assocaited with increased risk?
-strong genetic (200x) and environmental (20x) associations
Increased risk:
- Turner syndrome (XO)
- Edwards syndrome (tri 18)
- macrolide abx during pregnancy or breast feeding (erythromycin and azithromycin)
How might pyloric stenosis present?
(exam)
onset first 3-6 weeks
Presentation:
- regurgitation
- non-bilious vomiting following feeding
- demands refeeding after vomiting
Exam:
-2cm, non-tender, ovoid mass in epigastrium
What lab findings are associated with pyloric stenosis?
Due to loss of gastric fluids:
- hypochloremia (loss of Cl- from HCl)
- metabolic alkalosis (loss of H+ from HCl)
- hypokalemia (K+/H+ ATPase tries to recover H+ from gastric to compensate for alkalosis by exchanging H+ for K+)
What is Hirschsprung disease?
(epi and diagnositic)
also conginital/aganglionic megacolon
- failed migration of NCC through distal colon to form enteric ganglion cells (migrate from proximal to distal; RECTUM IS ALWAYS INVOLVED)
- results in absence of contractions -> dilation of affected region
Diagnosed by suction biopsy:
-absence of myenteric plexus (Auerbach) and submucosal plexus (meissner) on biopsy in affected portion of colon (rectum most commonly biospied as it is always involved)
How might Hirschsprung disease present?
(complications)
- failure to pass meconium shortly following birth
- eventual obstruction and constipation -> abdominal distension and bilious vomiting
Complications:
- enterocolitis
- fluid/electrolyte imbalance
- perforation
