Image of the Month—Diagnosis

The computed tomogram revealed evidence of pneumoperitoneum and distal migration of the straight biliary stent, which had protruded through a small-bowel loop (Figure 2). The presence of stent migration on the scout radiograph is suggested by the abnormal orientation of its distal end, which does not take the course of a native duodenum, as well as the unusually low position of its proximal end in relation to the visualized gas in the biliary tree.

The patient underwent an urgent laparotomy and retrieval of the stent, which had perforated a jejunal diverticulum. There was no sign of the pigtail stent. The involved segment of jejunum was resected, and the patient made an uneventful recovery. He underwent a further ERCP, with placement of a metal biliary stent followed by endovascular repair of the abdominal aortic aneurysm.

Migration of biliary endoprostheses can be early (developing during endoscopic insertion) or delayed (manifesting days to several months thereafter). Migration may be further classified as proximal (into the biliary system) or distal (into the duodenum or elsewhere in the bowel). Although delayed stent migration is not uncommon, distal impaction and secondary bowel perforation are rare, particularly beyond the ligament of Treitz.¹ Risk factors for bowel perforation include the use of straight or plastic stents, placement of a stent to manage benign biliary disease (particularly papillary stenosis), omission of sphincterotomy, and presence of abdominal wall hernias, bowel adhesions, or colonic diverticula.^2-4 To our knowledge, this is the first description of jejunal diverticular perforation secondary to migration of a plastic biliary stent. Whether the presence of a large abdominal aortic aneurysm also contributed in this case to recurrent stent dislocation and/or impaction is unclear. In cases of intraperitoneal perforation of the bowel, a laparotomy is usually required, although endoscopic, percutaneous, and laparoscopic approaches have been described.¹ To reduce the risk of distal stent migration, the use of stents with multiple intraductal flanges has been advocated.⁵

The development of unexplained abdominal pain in any patient with a history of biliary endoprosthesis, however distant, should always prompt consideration of this rare, but potentially lethal, complication.

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Correspondence: Muhammad F. Dawwas, MRCP, Cambridge Hepatobiliary Service, Box 210, Addenbrooke's Hospital, Hills Rd, Cambridge CB2 0QQ, United Kingdom (drdawwas@gmail.com).

Accepted for Publication: December 7, 2009.

Author Contributions:Study concept and design: Dawwas and Jah. Acquisition of data: Dawwas, Griffiths, Winterbottom, Huguet, and Gimson. Analysis and interpretation of data: Dawwas, Griffiths, Winterbottom, Huguet, and Gimson. Drafting of the manuscript: Dawwas, Jah, and Huguet. Critical revision of the manuscript for important intellectual content: Dawwas, Jah, Griffiths, Winterbottom, Huguet, and Gimson. Administrative, technical, and material support: Dawwas, Jah, and Huguet. Study supervision: Jah, Huguet, and Gimson.

Financial Disclosure: None reported.