Sigmoid diverticulum perforation induced by gallstone impaction post-sphincterotomy

Clinical History

93-year-old woman presented with right subchondral colic pain and was subjected to MRCP that manifested choledocholithiasis. The patient was subsequently subjected to ERCP-sphincterotomy, and presented eight days thereafter with acute onset rebound tenderness and fever. She underwent laparotomy, which revealed sigmoid diverticulum perforation secondary to gallstone impaction within a diverticulum.

Imaging Findings

Initial MRCP manifested 3 filling defects within the common bile duct, as well as intrahepatic bile duct dilatation.
The abdominal CT of second hospital admission revealed free intraperitoneal air, intrahepatic duct air, possibly due to prior sphincterotomy procedure, two calcified multifaceted structures within the sigmoid and within the peritoneal cavity respectively and sigmoid diverticulosis. The findings were in keeping with intra-and extraluminal gallstones. The intraperitoneal gallstone could have been expelled to the peritoneal cavity via perforation of a diverticulum. The bowel loops appeared with normal caliber without evidence of fluid-air levels.

Discussion

Background: Commonest complications of sphincterotomy and stone extraction occur in 10% of cases that include bleeding (2%), duodenal perforation (1%), cholangitis (2%), pancreatitis (2%), bile duct injury (<1%) and the usual complications with upper GI endoscopy (2%)[1].
Clinical Perspective: Reported complications of gallstone presence within the gastrointestinal tract include mechanical obstruction (gallstone ileus -15% of patients with biliary-enteric fistula)[2], and rare manifestations such as Bouveret syndrome (gastric outlet obstruction due to gallstone impaction within the duodenum in elderly women). The commonest sites of gallstone impaction are the ileocecal valve, distal ileum, jejunum, ligament of Treitz, duodenum, stomach, colon and any gastrointestinal stricture [3]. One case of gallstone-induced perforation of the terminal ileum with abscess formation has been reported [4].
Imaging Perspective: Preoperative diagnosis is made from a combination of plain X-ray and computed tomography (CT) scans.
Outcome: Management of gallstone ileus must be individualised. One-stage procedure should be offered only to highly selected patients with good cardiorespiratory reserve and with absolute indications for biliary surgery at the time of presentation.

Differential Diagnosis List

Final Diagnosis

Sigmoid diverticulum perforation induced by gallstone impaction post-sphincterotomy

URL:	https://www.eurorad.org/case/9028
DOI:	10.1594/EURORAD/CASE.9028
ISSN:	1563-4086