Chapter 43. Surgical Disorders

Pathophysiology

• Right-sided defect lateral to the base of the umbilical stalk through which a portion of the GI tract has herniated
• May be secondary to vascular accident with disruption of body wall formation or weakness at the insertion of the umbilical cord after involution of the right umbilical vein
• Exposure to amniotic fluid and partial closure of the defect may result in mesenteric vascular constriction → further bowel injury
• Bowel may be edematous and matted with inflammatory “peel”
• Small bowel with villous atrophy and blunting, muscular hypertrophy, and serosal inflammation

• Developmental arrest of somites in the abdominal wall or failure of midgut to return to the abdominal cavity after herniation into the umbilical stalk
• Central defect; umbilical ring fails to contract and leaves a round defect
• Defect is covered by a translucent mesenchymal membrane that protects the underlying abdominal organs from exposure to amniotic fluid
• The sac usually remains intact but occasionally is ruptured during delivery
• The liver and small intestine usually occupy part of the sac along with variable other abdominal organs

Epidemiology

• Sporadic; 1.5 of 10,000 live births
• Risk factors: Young maternal age; low SES; exposure to vasoconstricting decongestants, NSAIDs, cocaine, cigarette smoking, pesticides
• Can be associated with malrotation; associated with intestinal atresias in 5%–25%
• Not commonly associated with anomalies unrelated to the GI tract

• Sporadic; 2–2.5 of 10,000 live births
• Seen with mothers at extremes of reproductive age
• Associated with maternal obesity and SSRIs
• Associated with other structural or genetic defects in 50%–75%
• Associated syndromes: VACTERL association; Beckwith-Wiedemann syndrome; pentalogy of Cantrell; CHD; pulmonary hypoplasia; congenital malrotation of the colon; EEC syndrome; OEIS complex; trisomies 13, 18, and 21

Presentation and Diagnosis

• Usually diagnosed antenatally on US
• Mother has elevated AFP levels
• Most may still be delivered vaginally without further injury to the bowel

• Most diagnosed prenatally; should have a thorough evaluation for any other anomalies and consider chromosomal analysis
• Mother may or may not have elevated AFP levels

• May be delivered vaginally, but consider cesarean section for giant omphalocele because of concern for rupture

Treatment

• In delivery room, stabilize airway; wrap intestine with warm, sterile saline dressings; place-large bore orogastric tube to continuous suction; and place peripheral IV for fluid management and broad-spectrum antibiotics
• Place the infant in clear plastic bowel bag to minimize heat and water loss
• Inspect bowel for evidence of ischemia, torsion, and atresia
• Place the infant in lateral decubitus position to avoid mesenteric kinking
• Reduce or place the bowel in a sterile silo as soon as possible; delay may lead to bowel swelling and resultant ischemia
• If bowel is forced into abdominal cavity, may cause decreased diaphragmatic excursion, requiring increased ventilator support; may also impair mesenteric, hepatic, and renal perfusion
• During staged closure, parenteral nutrition, gastric decompression, and spontaneous breathing are preferred
• When reduction of silo contents is complete, final closure is performed
• Repair of atresias includes primary anastomosis, or if peel exists, internalization of uncorrected ...