Gallstone ileus involves small bowel obstruction following impaction of the stone within the lumen of the small intestine. This most often occurs at the ileocecal valve.
Bouveret's syndrome is rare and involves obstruction in the duodenum.
Other sites of obstruction:
(1) at the orifice to a colonic diverticulum
(2) at a point of luminal constriction (adhesion, tumor, other)
If the gallstone erodes into the peritoneal cavity, strictures caused by the inflammatory response can result in bowel obstruction.
Clinical features:
(1) Most patients are older (> 60 years of age); it is rare before the age of 50. The majority of patients are female.
(2) There may be an episode of acute cholecystitis prior to onset.
(3) The stone is usually >= 2.5 cm in diameter.
(4) Symptoms may be intermittent as the stone passes down then intestines.
(5) Often may not be diagnosed until the time of surgery.
Imaging studies:
(1) Flat abdominal films may show evidence of small bowel obstruction with dilated small bowel proximal to the site of obstruction.
(2) The presence of pneumobilia or a radio-opaque stone at the site of obstruction may be helpful but often may be absent.
(3) Ultrasound or CT scans may demonstrate the stone.
Management:
(1) While a proximal stone may be reached by endoscopy, most cases require surgical exploration with stone removal.
(2) Once one stone has been found, the entire GI tract should be examined for a second stone, especially if the first stone is multifaceted (as opposed to egg shaped).
(3) Cholecystectomy with closure of the fistula is an area of controversy and depends on the clinical status of the patient.
(3a) Often the fistula will resolve by itself.
(3b) Patients often are elderly and poor surgical candidates.
(3c) The surgery may be difficult due to active inflammation.
(3d) Damage to the main bile duct can occur if a cholecystectomy is attempted.
