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Difficulty: Very hardGastrointestinal and Abdominal Surgery

A 54-year-old man presents to the emergency department with a 12-hour history of severe, cramping abdominal pain and frequent vomiting. He has not had a bowel movement or passed flatus since the onset of his symptoms. His surgical history includes an open cholecystectomy performed 15 years ago. Vital signs show a temperature of 37.2°C (99.0°F), pulse of 98/min, respirations of 18/min, and blood pressure of 130/80 mm Hg. On physical examination, the abdomen is moderately distended and tympanic to percussion. Auscultation reveals high-pitched, hyperactive bowel sounds. There is moderate diffuse tenderness on palpation, but no guarding, rigidity, or rebound tenderness is appreciated. Laboratory investigations show a leukocyte count of 9,500/mm³ and a serum lactate level of 1.2 mmol/L. Cross-sectional imaging of the abdomen with intravenous contrast demonstrates multiple dilated small bowel loops measuring up to 4.5 cm in diameter. Furthermore, a cluster of U-shaped, fluid-filled bowel loops is identified in the mid-abdomen, with the associated mesenteric vessels radially converging toward a central focal point. The bowel wall enhancement is uniformly preserved, and there is no evidence of pneumatosis intestinalis or free intraperitoneal air. Which of the following is the most appropriate next step in the management of this patient?

  1. A
    Catheter-directed mesenteric angiography
  2. B
    Flexible endoscopic detorsion and decompression
  3. Urgent operative interventionAnswer
  4. D
    Gastrointestinal decompression with a nasogastric tube and close observation
  5. E
    Enteral administration of hyperosmolar radiopaque contrast

Answer

Urgent operative intervention
Urgent operative intervention is the correct next step because this patient's imaging demonstrates a closed-loop small bowel obstruction. Although his vital signs, physical examination, and laboratory values do not yet show overt signs of ischemia or peritonitis, a closed-loop obstruction (indicated by the U-shaped bowel loops and radially converging mesenteric vessels, known as the whirl sign) carries an exceptionally high risk of rapid progression to bowel strangulation, ischemia, and perforation. Therefore, it requires immediate surgical exploration regardless of the currently reassuring clinical parameters.

Step-by-Step Solution

1
Identify the clinical presentation
The patient has signs and symptoms of a mechanical small bowel obstruction (SBO), including colicky pain, vomiting, obstipation, and a history of prior abdominal surgery.
Establishing the primary clinical syndrome narrows the differential diagnosis to bowel obstruction.
2
Evaluate the clinical and laboratory severity markers
The patient lacks signs of systemic toxicity (normal vitals) and bowel ischemia (normal lactate, absence of peritonitis).
Typically, the absence of peritonitis or elevated lactate allows for a trial of conservative management in SBO. However, imaging must be reviewed to confirm it is uncomplicated.
3
Interpret the specific imaging findings
The CT scan reveals U-shaped bowel loops and radially converging mesenteric vessels (the 'whirl sign').
These findings are pathognomonic for a closed-loop obstruction, a specific type of mechanical obstruction where a segment of bowel is occluded at two points.
4
Determine the appropriate management algorithm
A closed-loop obstruction mandates immediate surgical exploration.
Despite reassuring clinical parameters and preserved wall enhancement, closed-loop obstructions have an exceptionally high risk of rapid progression to strangulation, ischemia, and perforation, making conservative management contraindicated.

Key Concept

Radiographic diagnosis of closed-loop small bowel obstruction and its indication for immediate surgery.
Estimated Time:1m 30s
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Topics

Gastrointestinal and Abdominal Surgery

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