Biliary Stent Migration: A Rare Cause Of Right-Sided Pulmonary Abscess
INTRODUCTION: Biliary stent migration is a well established complication of biliary stent placement, and while approximations vary, most estimate that stent migration occurs in 10% of cases (1). Many of these cases are asymptomatic, but some will go on to develop worsening biliary obstruction, intestinal perforation, and pelvic abscesses. We present a rare complication of biliary stenting with proximal migration through the right diaphragm causing a pulmonary abscess.
CASE PRESENTATION: 73 year old lady with a history of cholangiocarcinoma status post partial right hepatectomy. Her postoperative course was complicated by a bile leak requiring ERCP with sphincterotomy and biliary stent placement. Five months later, this stent developed stricture and an additional stent was placed. A small right exudative pleural effusion was found. CT chest did not show loculation. She was discharged on Augmentin for pus in the biliary tree and suspected pneumonia. Despite this, she returned to the ER seven days later with worsening shortness of breath and sepsis. Repeat chest x-ray showed worsening right sided pleural effusion with "air bubble." CT chest displayed clear migration of the biliary stent through the diaphragm into the right lung with an associated pulmonary abscess surrounding the stent. Patient was started empirically on Zosyn. ERCP was performed with stent retrieval/exchange, and a successful right sided VATS procedure with washout was performed without any additional complications. Blood and fluid cultures were unremarkable.
DISCUSSION: To our knowledge, this is the first case in the literature of proximal biliary stent migration causing a pulmonary abscess. We suspect that the patient's recent right lobe hepatectomy weakened the right diaphragm predisposing to biliary stent migration in this manner. It should be noted that bronchobiliary fistula formation is a known complication following hepatectomy, but no evidence of this was noted on ERCP or CT imaging. Furthermore, this patient did not experience bilioptysis, a hallmark of bronchobiliary fistula formation. The literature suggests risk factors for biliary stent migration include bile duct diameter >10mm, straight plastic stents, benign stricture, and stent duration greater than 1 month. While malignancy is a less common cause of stent migration, cholangiocarcinoma is considered the highest risk malignancy for this complication (3).
CONCLUSIONS: This patient presented with an unusual cause of shortness of breath. Chest x-ray in this case was vital in helping to identify a worsening effusion, but it should be noted that plastic stents will not appear on this imaging modality (2). CT scan remains the gold standard for detection of stent migration, and providers should have a low threshold to order CT imaging in patients with recent biliary procedures and right sided effusion.
Pottmeyer G, Mundell J. Biliary Stent Migration: A Rare Cause Of Right-Sided Pulmonary Abscess. Chest. 2021; 160(4 Suppl.): A327. doi: 10.1016/j.chest.2021.07.330