Deadly Gallstone!

Abstract

Purpose: Introduction: Colonic obstruction due to gallstone is an uncommon event. It is mainly seen in elderly women with significant comorbidities and therefore with high mortality rate. We report a case of 77-year-old woman presented with large bowel obstruction due to gallstone which turned out to be a lethal for her. Case: A 77-year-old woman presented with right lower abdominal pain, vomiting and constipation for 6 days. Physical examination showed tachycardia and tender right lower abdomen with hyperperistalsis. Labs reveled leucocytosis (WBC 13.5) and normal chemistry. CT scan of abdomen showed 3 cm hyperdense lesion at junction of sigmoid colon and rectum causing obstruction. Exploratory laparotomy discovered the migration of a large gallstone into the colon by a cholecystocolic fistula, blocking the sigmoid colon. Resection of sigmoid colon with intraluminal obstructing gallstone, extended right hemicolectomy with takedown of cholecystocolic fistula, cholecystectomy, primary anastomosis of descending colon to rectum and ileum to transverse colon with diverting ileostomy was performed. Her post-operative course was complicated with respiratory failure and stool leakage from the distal anastomosis. Patient underwent another colostomy. However despite all these efforts, her respiratory status continued to worsen and patient died on post-operative day 17. Discussion: Intestinal obstruction (IO) by gallstone (Gallstone ileus), although an uncommon etiology of mechanical IO, accounts for 1% to 4% of all cases of IO, mostly found in the elderly female (F:M = 4:1). Distal ileum is the most common location (50-75%), while colon is a more rare location (2-8%). Large gallstone (>2.5 cm) enters to intestine through fistula, a rare complication of cholelithiasis (1-3%). Fistula forms when gallbladder ruptures into adherent viscera or when a large gallstone causes pressure necrosis of the gall bladder wall, leading to perforation. Fistula mostly involves the duodenum (60-75%) followed by colon (15%), jejunum and stomach. Abdominal CT demonstrates pneumobilia (75%), bowel obstruction and an impacted gallstone (Rigler's triad). Gallstone ileus requires emergency enterolithotomy to relieve obstruction. However, parallel surgery for fistula is discouraged. Recurrent obstruction occurs in 3% to 5% cases, prompting consideration of single stage surgery but relief of obstruction should be primary goal. Definitive fistula surgery should be deferred to elective setting where morbidity must be weighed against surgical complications. Although a rare occurrence, gallstone ileus should be kept in mind in IO, especially in elderly patients. A minimal approach is suggested as mortality rate is very high (15-20%).