Rigler's triad

Rigler's Triad

Rigler's triad is a set of three radiographic findings that are indicative of gallstone ileus, a rare form of bowel obstruction. The triad is named after the American radiologist Leo George Rigler, who first described it.

Components of Rigler's Triad

Rigler's triad consists of the following three findings on an abdominal X-ray or CT scan:

1. Pneumobilia: The presence of air within the biliary tree, which is indicative of an abnormal connection between the gastrointestinal tract and the biliary system.
2. Small bowel obstruction: Evidence of obstruction in the small intestine, which can be identified by dilated loops of bowel and air-fluid levels.
3. Ectopic gallstone: The presence of a gallstone outside the gallbladder, typically within the intestinal lumen, which is the cause of the obstruction.

Pathophysiology

Gallstone ileus occurs when a large gallstone erodes through the wall of the gallbladder into the adjacent gastrointestinal tract, usually the duodenum. This creates a cholecystoenteric fistula, allowing the gallstone to pass into the intestines. If the gallstone is large enough, it can become lodged in the small intestine, leading to obstruction.

Diagnosis

The diagnosis of gallstone ileus is often challenging due to its nonspecific symptoms, which can include abdominal pain, nausea, and vomiting. Rigler's triad is a crucial diagnostic tool that can help identify the condition on imaging studies. A high index of suspicion is necessary, especially in elderly patients with a history of gallstones.

Treatment

The treatment of gallstone ileus typically involves surgical intervention to relieve the obstruction. This may include:

• Enterolithotomy: Surgical removal of the gallstone from the intestine.
• Cholecystectomy: Removal of the gallbladder, which may be performed at the same time as the enterolithotomy or as a separate procedure.
• Repair of the cholecystoenteric fistula.

Prognosis

The prognosis of gallstone ileus depends on several factors, including the patient's overall health, the size and location of the gallstone, and the presence of any complications such as peritonitis or sepsis. Early diagnosis and prompt surgical intervention are critical for improving outcomes.

See also

• Gallstone
• Bowel obstruction
• Pneumobilia
• Cholecystoenteric fistula