GI Disorders of the Young Flashcards
List the common congenital gastrointestinal anomalies found in infants and children.
Abdominal wall defects (incidence in U.S. = 1/2000) o Omphalocele o Gastroschisis o Umbilical hernia o Diaphragmatic hernia Diagnose: • Prenatal ultrasound • Maternal serum alpha-fetoprotein = elevated
Other anomalies of GI tracts: Atresia (interruption of lumen) • Esophageal atresia • Duodenal atresia Stenosis (narrowing of lumen) • Duodenal stenosis • Pyloric stenosis Duplication (incomplete recanalization resulting in parallel lumen)
Omphalocele
Developmental defect of abdominal wall at umbilicus
o Covered by membranous sac
Frequently associated with other congenital anomalies:
• 35% have other GI defects
• 20% have congenital heart disease
• 10% have Beckwith-Wiedemann syndrome (gigantism, visceromegaly, macroglossia, hypoglycemia)
• Can be associated with Trisomy 13, 14, 18, 21
- More common than gastroschisis
- Associated with lower gestational age
Treatment:
o Fluid resuscitation after delivery
o Orogastric intubation with continuous low suction (prevent organs from getting distended)
o Infant placed in lateral position
o Exposed viscera to be covered with warm saline-soaked gauze and plastic wrap
o Prevention of bowel angulation to prevent compromising vascular supply
o Surgical consultation
o Recovery = faster; enteral feeding can be started after 2-3 days
o Complications: obstruction, necrotizing enterocolitis
Gastroschisis
Defect separate from umbilicus (laterally) with NO covering sac
o Usually to the right side of umbilicus (for unknown reasons)
o 14% have associated jejunoileal malformation
o ~4% have extraintestinal anomaly
o 50-60% are premature
- Incidence inversely related to maternal age
- Associated with lower gestational age (infants usually smaller)
Treatment
o Fluid resuscitation after delivery
o Orogastric intubation with continuous low suction (prevent organs from getting distended)
o Infant placed in lateral position
o Exposed viscera to be covered with warm saline-soaked gauze and plastic wrap
o Prevention of bowel angulation to prevent compromising vascular supply
o Surgical consultation
o Recovery = slower; may need IV parenteral nutrition initially
o Complications: obstruction, necrotizing enterocolitis
Omphalocele vs. Gastroschisis
Omphalocele:
- Covered in membrane
- Umbilical defect
- Often associated with other congenital issues
Gastroschisis
- No membrane sack
- Defect lateral to umbilicus
- Less often associated with other congenital issues
Umbilical hernia
Incomplete closure of umbilical ring
o Defects greater than 1.5 cm at 2 years may need surgical closure
o Ring less than 1.5 cm will close by 4 years
- More common in premature infants
- Found in ~40% of black infants
Diaphragmatic hernia
Defect when intrabdominal organs are displaced into thorax through posterolateral diaphragmatic opening (usually on left)
o Hinders lung development → lung hypoplasia
o Usually some degree of malrotation of intestines
Prevalence: 1/4,000 births
o No gender or racial differences
• Diagnosed by prenatal ultrasound
Clinical presentation: hollow abdomen, respiratory distress, displaced heart sounds
Esophageal atresia and Tracheoesophageal fistula (TEF)
o Occurs: 1/3000-4000 live births
5 anatomical variants:
• A: most common (85%) = blind upper esophageal pouch with fistula between lower esophageal segment and lower part of trachea
• B: Complete Atresia (8%) 2 blind pouches without presence of TEF
• C: “H-type” = (4%) a fistula exists between intact esophagus and trachea
Risk factors:
• 0.5-2% risk recurrence in siblings
• Estrogen/progesterone during pregnancy = possible teratogens
• Polyhydramnios (too much amniotic fluid) present in 50% of mothers
Associated with:
• VACTERL (vertebral, anal, cardiac, tracheoesophageal, renal, limb anomalies)
• Others anomalies: hypospadias, undescended testis, duodenal atresia, hydrocephalus secondary to aqueductal stenosis
Presentation:
• Absence of fetal stomach after 20 weeks gestation = suggests EA but NOT diagnostic
• EA: frothing saliva, respiratory distress that worsens with feedings
• Type H TEF: chronic respiratory problems and bronchospasm with recurrent infections
Treatment
• Goal = maintain airway and prevent aspiration
• Intubation should be avoided
• Surgical TEF ligation and end to end anastomosis of esophagus if gap is short
• Long gap: gastrostomy with suction at upper pouch, colonic interposition required
Pyloric Stenosis
6-8/1000 live births • 2.5x more common in Caucasians • More common in 1st born males • Subsequent siblings and offspring at increased risk • Etiology unknown
Clinical features:
• Progressive vomiting at 3 to 6 weeks of age
• 20% are symptomatic at birth
• Infant is hungry and irritable, becomes malnourished
• Gastric peristalsis may be visible
• Hypokalemic, hypochloremic alkalosis occurs
• Jaundice occurs in 2 to 5%
• “Olive-shaped mass” in upper abdomen
Diagnosis • Ultrasound • Upper GI x-ray Normal values: • length less than 15 mm • Single muscle thickness less than 3 mm (if over 5 = thickened) • Pyloric width less than 7 mm
Treatment
• Surgical plyloromytomy
Duodenal atresia
Obstruction at the ampulla of Vater • Atresia, membrane, stenosis o 1 per 5000 live births o Associated with trisomy 21, congenital heart disease, esophageal atresia, malrotation, anorectal anomalies o Presents as vomiting following birth
Diagnosis:
• Prenatal ultrasound
• Plain abdominal radiograph → characteristic double bubble sign
Treatment
• Gastric decompression
• Surgical duodeno-duodenostomy
Jejunoileal atresia
o Ischemic infarction of a segment of fetal intestine
o Presents as bilious vomiting and abdominal distension
Treatment
• Decompression
• Resection with anastomosis
Patterns of small bowel atresia
• Type 1: in continuity
• Type 2: connecting band and mesenteric defect
• Type 3A: atresia with mesenteric defect
• Type 3B: extensive mesenteric defect and “apple peel” bowel
• Type 4: multiple atresias
Pyloric Stenosis vs Duodenal Atresia
Pyloric stenosis
- more common in white, 1st born males
- most present around 3 weeks
- non-bilious vomiting, hungry
- hypochloremic, hypokalemic, metabolic alkalosis
Duodenal Atresia
- associated with other congenital anomalies
- present within days of birth
- bilious vomiting
Abnormalities of intestinal rotation
Arrest in intestinal rotation in fetal life
• Incidence 1:6000 live births
Clinical presentation:
• May be asymptomatic
• May present at any time with volvulus resulting in intestinal ischemia
o Frequently associated with other anomalies (gastroschisis, omphalocele)
Types: 1) Non-rotation • Most common • Cecum lying on left; small bowel on right of superior mesenteric artery • Result = foreshortened mesentery • Little to no fixation of bowel = more mobile → potential to twist and cut off blood supply 2) Incomplete rotation 3) Paraduodenal hernia 4) Reverse rotation
Midgut malrotation with volvulus = surgical emergency
Abnormal position of the midgut:
• Duodenum lies to right of spine
• Results in narrow mesentery = can twist around the pedicle of the superior mesenteric artery → midgut ischemia
Presents as bilious vomiting, abdominal pain, abdominal pain and tenderness
• Corkscrew appearance on x-ray
Treatment: urgent laparotomy
GI tract duplications
Can occur anywhere in the GI tract
Most common = ileum (50%)
Gastric (5-7%
• Usually in girls
• Usually cystic, located on greater curvature
• Have no communication with stomach
Duodenal (<6%)
• Usually cystic
• Do not communicate with intestinal lumen
• Commonly have symptoms of obstruction
• 10-15% have ectopic gastric mucosa and can present with bleeding
Rare = colon
• May be associated with genitourinary malformation
• Higher incidence of malignant degeneration
• Constipation, obstruction, volvulus occur more commonly
- Located on mesenteric side of bowel
- Share a common blood supply wit adjacent bowel
Common features:
• Attached to normal GI tract
• Well-developed smooth muscle wall (usually of 2 layers)
• Lined with mucosa or epithelium similar to stomach, small intestine or colon
• Generally isolated anomalies
• Located on the mesenteric site of bowel
• Share a common blood supply with adjacent bowel
Symptoms: obstruction, ulceration, pain, bleeding, perforation, fistulae
Treatment: surgical excision
Meckel’s diverticulum
Remnant of omphalomesenteric duct (joining yolk sac to midgut lumen during development) = extra bulge/pouch off small intestine
The rules of two:
• 2% of population
• M:F ratio 2:1
• Located within 2 feet of ileocecal valve
• Measures about 2 inches long and 2 cm in diameter
• 2 types of ectopic mucosa: gastric (80%) and pancreatic (5%)
• Usually symptomatic in 50% of children before 2 years of age
Intussusception
Invagination or telescoping of part of the intestine into itself
• 2/3 of cases occur in 1st year of life (peak incidence at 4-10 months)
• 2nd most common cause of obstruction after pyloric stenosis (incidence of 1-4/1000 births)
o Most are ileo-colic
o Male: female 3:2
o Most cases are idiopathic = NO lead point (anatomic anomaly predisposing to invagination)
• Likely from swollen, hypertrophied Peyer’s patches
Lead points in older children • Meckel diverticulum • Lymphoma or other neoplasm • Hematoma: HSP, hemophilia • Polyps • Duplication • Cystic fibrosis (inspissated stool)
Presentation
• Colicky abdominal pain, frequently associated with vomiting
• Pallor, “currant jelly” stool
Diagnosis
• Ultrasound or contrast enema
• See “sausage” sign on x-ray
Treatment • Fluid resuscitation • Decompression • Air contrast enema or pneumatic reduction • Surgical correction
