Gallstone ileus
💡 Clinical Pearl: Always consider gallstone ileus in an elderly woman with SBO but no previous abdominal surgery. The classic triad on AXR is diagnostic but only seen in ~30–50% of cases. CT is the investigation of choice.
💡 About
- Gallstone ileus is a rare but important cause of small bowel obstruction, accounting for 1–4% of SBO cases (higher in the elderly).
- Occurs when a cholecysto-duodenal fistula forms between the gallbladder fundus and the adjacent duodenum due to chronic inflammation.
- A large gallstone (>2.5 cm) passes into the bowel lumen, most often lodging in the terminal ileum where the lumen narrows, causing mechanical obstruction.
- Predominantly affects elderly women with long-standing gallstone disease.
⚠️ Symptoms and Signs
- ⏳ Subacute or intermittent obstruction - "tumbling obstruction" as the stone moves along the bowel before lodging.
- 😣 Colicky abdominal pain, distension, constipation/obstipation.
- 🤢 Vomiting (may be bilious initially, later faeculent in advanced obstruction).
- 📜 Past history of gallstones or flatulent dyspepsia often present.
- 👵 Seen most commonly in elderly females with no prior abdominal surgery (important clue as adhesions are the leading SBO cause in younger patients).
🧪 Investigations
- 📸 Abdominal X-ray (AXR): May demonstrate Rigler’s triad:
- Dilated small bowel loops (SBO).
- Air in the biliary tree (pneumobilia).
- Aberrant gallstone within the intestinal lumen.
- 🧲 CT Scan (gold standard): More sensitive in detecting pneumobilia, transition point, and the ectopic stone.
- 🔬 Bloods: May show dehydration, electrolyte disturbance, or raised inflammatory markers if secondary infection present.
🛠️ Treatment
- 🚑 Resuscitation first: IV fluids, correction of electrolytes, NG tube for decompression.
- 🔪 Laparotomy with enterolithotomy: Removal of the obstructing gallstone via enterotomy. Sometimes the stone can be ‘milked’ into the caecum and removed without enterotomy.
- ⚖️ One-stage vs two-stage surgery:
- One-stage: Enterolithotomy + cholecystectomy + fistula repair (rarely done in acutely unwell elderly due to high risk).
- Two-stage (common): Enterolithotomy to relieve obstruction, with delayed cholecystectomy if gallbladder symptoms persist.
- 📉 Mortality remains high (~15–20%) due to elderly, frail patient population and late presentation.
