What is the diagnosis and treatment for a newborn with suspected jejunal atresia presenting with bilious vomiting, abdominal distension, and failure to pass meconium?

Jejunal Atresia: Diagnosis and Management

For a newborn presenting with bilious vomiting, abdominal distension, and failure to pass meconium, begin with plain abdominal radiographs to identify the pattern of bowel obstruction, followed by contrast enema if distal obstruction is suspected, and proceed to surgical correction with bowel resection and anastomosis once the diagnosis is confirmed. 1, 2

Diagnostic Approach

Initial Imaging

• Plain abdominal radiographs are the first-line imaging study for all suspected bowel obstruction, demonstrating dilated bowel loops, air-fluid levels, and the presence or absence of distal gas 3
• Look for multiple dilated loops with variable amounts of distal gas, which distinguishes jejunal atresia from more proximal obstructions like duodenal atresia (which shows the classic "double bubble" sign) 1, 4

Differentiating Jejunal Atresia from Other Causes

If radiographs show few distended bowel loops or a nonclassic pattern:

• Upper GI series is the reference standard to rule out malrotation with midgut volvulus, which is a surgical emergency requiring urgent intervention 1, 3
• The UGI series identifies abnormal position of the duodenojejunal junction (ligament of Treitz) with 96% sensitivity for malrotation 1
• Critical pitfall: Malrotation with incomplete obstruction may have a normal bowel gas pattern, so maintain high suspicion in bilious vomiting within the first 2 days of life 1

If radiographs suggest distal obstruction:

• Contrast enema is the diagnostic procedure of choice, as it differentiates between meconium plug, ileal atresia, meconium ileus, and Hirschsprung disease 2, 3
• Contrast enema may show microcolon (due to lack of contents moving through the bowel) and helps identify the transition zone 2, 3
• Avoid the pitfall of assuming Hirschsprung disease and proceeding directly to rectal biopsy without contrast enema, as multiple conditions present identically 2

Ultrasound Has No Role

• The American College of Radiology states ultrasound has no role in evaluating neonates with suspected distal obstruction like jejunal atresia 2
• Exception: Ultrasound may detect the "whirlpool sign" if midgut volvulus is present, which can help substantiate an equivocal UGI study 1

Surgical Management

Definitive Treatment

• Surgical excision of the involved bowel with end-to-end anastomosis is the definitive treatment for jejunal atresia 5
• The procedure involves small bowel tapering or excision of the dilated proximal segment and anastomosis to the distal bowel 6

Surgical Technique Options

Standard approach:

• Circumumbilical incision provides adequate access to jejunal atresia with superior cosmesis compared to classical transverse laparotomy 6
• The small bowel is easily accessible through this minimal access approach in the vast majority of cases 6

For complex jejunal atresia (Type 2-4):

• Bishop-Koop anastomosis with early enteral nutrition significantly improves outcomes compared to primary anastomosis, with mortality reduction from 71.4% to 45.5% in low-resource settings 7
• This approach is particularly valuable when dealing with severe bowel length discrepancy or multiple atresias 7

Alternative technique:

• Intestinal plication of the dilated proximal bowel with end-to-oblique anastomosis preserves mucosal absorptive surface and allows earlier return of function than resection or tapering 8

Postoperative Management

• Postoperative hypoperistaltic bowel is a common complication that can be minimized by adding oral prokinetics in a controlled manner once enteral feeding begins 5
• Anastomotic strictures occur in approximately 12-15% of cases and may require revision through the same incision 6
• Early enteral nutrition is critical for improving outcomes, particularly in complex cases 7

Key Clinical Distinctions

Jejunal vs. Duodenal Atresia

• Jejunal atresia results from intrauterine mesenteric vascular accidents, not failure of recanalization like duodenal atresia 4
• Jejunal atresia presents with multiple dilated loops rather than the isolated "double bubble" sign of duodenal atresia 4, 3
• Meconium passage is typically absent in both conditions, but the radiographic pattern differs 4

Timing and Urgency

• Most congenital intestinal atresias present within the first 2 days of life 1
• The most critical diagnosis to exclude is midgut volvulus, which requires urgent surgery and can present with similar symptoms 1, 3
• Bilious vomiting in a neonate is a surgical emergency until proven otherwise 1