Gallstone ileus: a review
Executive Summary
Gallstone ileus is a rare but critical complication of cholelithiasis, occurring when a gallstone enters the intestinal tract—typically via a cholecystoenteric fistula—and causes mechanical obstruction. While surgical intervention is the standard treatment, the medical community remains divided on the optimal approach: a one-stage operation (simultaneous stone extraction and fistula repair) or a two-stage operation (initial stone extraction followed by delayed fistula repair).
This document synthesizes findings from clinical reviews to provide a comprehensive overview of the disease's epidemiology, pathogenesis, and diagnostic criteria. The central conclusion is that surgical strategy must be tailored to the specific site of stone impaction. One-stage surgery is recommended for duodenal and colonic impactions, while a two-stage approach is generally preferred for obstructions in the small intestine to minimize perioperative mortality.
1. Overview and Epidemiology
Gallstone ileus represents a small fraction of gallbladder-related complications and general intestinal obstructions.
Incidence: The condition occurs in approximately 0.15% to 1.5% of cholelithiasis cases.
Total Ileus Contribution: It accounts for less than 0.1% of all mechanical ileus cases.
Demographics: The disease predominantly affects elderly patients, often those with significant comorbidities. In reported cases, female patients outnumber male patients significantly (e.g., a 1.86 ratio in Bouveret syndrome and nearly 3.0 in sigmoid cases).
Recurrence: The risk of recurrence is estimated between 5% and 8%.
2. Pathogenesis and Impaction Dynamics
The condition is initiated by the formation of an internal biliary fistula, usually resulting from chronic inflammation or vascular insufficiency caused by large calculi pressing against the gallbladder wall.
Common Fistula Routes
The majority of gallstones (75%–83%) enter the digestive tract through a fistula between the gallbladder and the duodenum. Rare routes include the stomach, the colon, or passage through the common bile duct.
Impaction Sites and Stone Characteristics
Stones prone to impaction are typically ≥ 2.5 cm in diameter, with the average size around 4 cm. They are primarily of the cholesterol type.
3. Diagnosis and Clinical Presentation
Gallstone ileus lacks highly distinctive symptoms, often leading to delayed diagnosis. A characteristic feature is "tumbling gallstone" advancement, where the patient experiences alternating periods of aggravation and resolution as the stone moves through the tract.
Clinical Symptoms
Common presentations across various studies include:
Abdominal Pain: 71% to 91.5% of patients.
Vomiting/Nausea: 50% to 87% of patients.
Abdominal Distension: 26% to 84.7% of patients.
Other: Constipation (61% in sigmoid cases), fever (40.9%), and occasionally haematemesis or weight loss.
Diagnostic Imaging
Plain Radiography: Historically uses "Rigler’s triad" (pneumobilia, intestinal dilatation, and ectopic calculus), though all three signs appear in less than 50% of cases.
Computed Tomography (CT): The gold standard. Contrast-enhanced CT offers a sensitivity of 93%, specificity of 100%, and accuracy of 99%. It is significantly more effective than X-rays at identifying ectopic gallstones (81% vs. 33%).
Endoscopy/Ultrasound: Useful for visualizing the fistula or impacted calculus in the upper gastrointestinal tract.
4. Surgical Management Paradigms
The primary debate in treatment is the trade-off between the invasiveness of the procedure and the long-term risks of a persistent fistula.
One-Stage vs. Two-Stage Procedures
Risks of Persistent Cholecystoenteric Fistulas
Failure to close the fistula carries significant long-term risks:
Recurrence: Recurrent ileus usually manifests within 6 months.
Cholangitis: Occurs in 11% of cholecystoduodenal fistulas and 60% of cholecystocolonic fistulas.
Carcinogenesis: Approximately 15% of cases with persistent fistulas are complicated by gallbladder cancer.
5. Site-Specific Treatment Recommendations
The review concludes that the surgical approach should be dictated by the site of impaction to optimize patient outcomes.
Duodenal Impaction (Bouveret Syndrome)
Recommendation: One-stage surgery is the treatment of choice.
Rationale: The fistula and the stone are in the same surgical field. Lithotomy can be performed through the resection site of the fistula, making the procedure technically simpler and providing favorable outcomes.
Small Intestinal Impaction
Recommendation: Two-stage surgery (enterolithotomy alone) is the standard.
Rationale: Patients often present in poor general condition. Simple lithotomy releases the obstruction quickly with lower mortality. Natural closure of the fistula occurs in 61.5% of cases; if the fistula remains patent after 3–6 months, radical surgery can then be performed.
Colonic Impaction
Recommendation: One-stage surgery is the treatment of choice.
Rationale: Unlike the small intestine, natural closure of a cholecystocolonic fistula is rare (approx. 10%). There is an exceptionally high risk of reflux cholangitis and sepsis due to the backflow of fecal fluid through the fistula.
6. Alternative and Minimally Invasive Approaches
Laparoscopy: Laparoscopically assisted enterolithotomy is associated with shorter hospital stays compared to open laparotomy. It is highly recommended for two-stage procedures in the small intestine.
Endoscopic Lithotripsy: Methods include mechanical, electrohydraulic, laser (YAG), or extracorporeal shock wave lithotripsy (ESWL).
Limitations: These are less reliable than surgery; fragments may re-impact further down the tract.
Application: Reserved for elderly patients who cannot withstand general surgery.
7. Conclusion
Treatment for gallstone ileus must be individualized based on the site of impaction and the patient's physiological reserves. While two-stage surgery is safer for the majority of small intestine cases, the unique anatomical and infectious risks associated with duodenal and colonic impactions necessitate a more definitive one-stage surgical intervention when the patient's condition permits.
