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Difficulty: HardGastrointestinal and Abdominal Surgery

A 79-year-old woman is admitted to the surgical ward with a 3-day history of intermittent, severe abdominal cramps and frequent vomiting of green-tinged fluid. She has not had a bowel movement or passed flatus for the past 48 hours. Her past medical history includes essential hypertension, osteoarthritis, and several episodes of self-resolving right upper quadrant pain over the last decade. She has never undergone any surgical procedures. On admission, her temperature is 37.4°C (99.3°F), blood pressure is 105/65 mmHg, and heart rate is 108/min. The abdomen is significantly distended, tympanitic to percussion, and diffusely tender without guarding or rebound. Bowel sounds are hyperactive and high-pitched. Laboratory evaluation shows a leukocyte count of 11,200/mm³ and serum creatinine of 1.6 mg/dL (baseline 0.9 mg/dL). Cross-sectional abdominal imaging with contrast reveals markedly dilated loops of small bowel up to the terminal ileum, where a 3.5-cm radiopaque structure is lodged. There is also air visible within the biliary tree. After initial fluid resuscitation, which of the following is the most appropriate next step in management?

  1. Enterotomy with extraction of the obstructing mass aloneAnswer
  2. B
    Enterotomy with extraction, cholecystectomy, and fistula closure
  3. C
    Continuation of nasogastric decompression and serial clinical observation
  4. D
    Enteral administration of a water-soluble radiopaque contrast agent
  5. E
    Intravenous administration of a gastrointestinal prokinetic agent

Answer

Enterotomy with extraction of the obstructing mass alone
This patient's presentation of a small bowel obstruction (SBO) combined with imaging showing a radiopaque mass in the terminal ileum and pneumobilia represents the classic Rigler triad, which is pathognomonic for gallstone ileus. Gallstone ileus occurs when a large gallstone erodes through the gallbladder wall directly into the adjacent duodenum, creating a cholecystoduodenal fistula. The stone travels down the gastrointestinal tract and typically impacts at the narrowest portion of the small bowel, the terminal ileum, causing a complete mechanical obstruction. The most appropriate management for the vast majority of these patients, who are usually elderly and have multiple medical comorbidities, is a simple longitudinal enterotomy proximal to the site of impaction to extract the stone, followed by primary transverse closure. This straightforward procedure relieves the acute, life-threatening obstruction with the lowest possible morbidity and mortality.

Step-by-Step Solution

1
Analyze the clinical presentation and patient history.
An elderly female with no prior abdominal surgeries presents with clinical signs of a small bowel obstruction (vomiting, distension, absent flatus) and a history suggestive of chronic biliary colic.
Establishing the presence of a bowel obstruction in a 'virgin abdomen' raises suspicion for etiologies other than postoperative adhesions, such as hernias, tumors, or gallstone ileus.
2
Interpret the cross-sectional imaging findings.
Imaging displays the classic Rigler triad: small bowel obstruction, pneumobilia (air in the biliary tree), and an ectopic radiopaque gallstone lodged in the terminal ileum.
These specific radiological signs definitively confirm the diagnosis of gallstone ileus resulting from a cholecystoenteric fistula.
3
Determine the safest and most definitive surgical management.
The best approach is a simple enterolithotomy (enterotomy to extract the stone) without concurrent biliary surgery.
In elderly and often frail patients with significant comorbidities, the primary goal is to resolve the life-threatening obstruction. Adding a cholecystectomy and fistula repair (a one-stage procedure) drastically increases mortality and is generally avoided.

Key Concept

Gallstone ileus is a mechanical small bowel obstruction caused by a large gallstone impacting in the terminal ileum, classically presenting with the Rigler triad (SBO, pneumobilia, ectopic gallstone), and is best managed surgically with an enterolithotomy alone.
Estimated Time:1m 30s
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Topics

Gastrointestinal and Abdominal Surgery

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