Pneumoperitoneum Caused by Transhepatic Air Leak After Metallic Biliary Stent Placement Jei Hee Lee, 1,2 Deok Hee Lee, 1,3 Jeong-Sik Yu, 1,2 Se Joon Lee, 4 Woo-Cheol Kwon, 1,2 Ki Whang Kim 1,2 1 Department of Diagnostic Radiology, Yonsei University College of Medicine, YongDong Severance Hospital, 146-92 Dokok-Dong, Kangnam-Ku, Seoul 135-270, South Korea 2 Research Institute of Radiological Science, Yonsei University, 134 Shinchon-Dong, Seodaemun-Ku, Seoul 120-752, South Korea 3 Department of Diagnostic Radiology, Asan Kangnung Hospital 415 Bandong-Ri, Sacheon-Myon, Kangnung-Si, Kangwon-Do, 210-711, South Korea 4 Department of Internal Medicine, Yonsei University College of Medicine, YongDong Severance Hospital, 146-92 Dokok-Dong, Kangnam-Ku, Seoul 135-270, South Korea Abstract A self-expanding metallic biliary stent was placed for palliation of a common bile duct obstruction in a 68-year-old male with unre- sectable pancreatic head cancer 3 days after initial percutaneous right transhepatic catheter decompression. The stent crossed the ampulla of Vater. Three days later, the stent was balloon-dilated and the percutaneous access was removed. At removal, a small contrast leak from the transhepatic tract was seen. Three days later, pneumoperitoneum was found with symptoms of peritoneal irrita- tion and fever. A widely open sphincter of Oddi caused by the metallic stent, accompanied by delayed sealing of the transhepatic tract, may have caused the air and bile leakage into the peritoneal space. This case shows that pneumoperitoneum may occur without ductal tear or bowel injury, with a biliary stent crossing the ampulla of Vater. Key words: Bile ducts, interventional procedure—Stents and pros- theses—Pneumoperitoneum During the last decade, percutaneous transhepatic placement of metallic stents has become popular in the palliation of malignant extrahepatic duct strictures [1– 4]. For common bile duct (CBD) obstruction, stents are placed across the ampulla of Vater. The possible complications caused by sacrificing the function of the sphincter of Oddi have not been well documented. Here we report a case of pneumoperitoneum occurring after transpapillary metallic biliary stent placement. Case Report A 68-year-old male presented with a 1-week history of progressive painless jaundice. Physical examination was unremarkable except for mild jaundice. Abnormal laboratory studies included a serum total bilirubin of 20.6 mg/dl (normal 0.2–1.4 mg/dl) and alkaline phosphatase of 633 U/L (normal 40 –120 U/L). Contrast-enhanced CT of the abdomen revealed an infiltra- tive, low-density mass involving the head of the pancreas and invading the superior mesenteric vein, which proved to be adenocarcinoma by needle- aspiration cytology. For palliation of biliary obstruction, percutaneous bil- iary drainage with an 8.5 Fr drainage catheter was performed via a right transhepatic approach. On the cholangiogram, a severe stricture of the CBD was observed. Three days later, through the preexisting transhepatic tract, a 6-cm  10-mm self-expanding nitinol stent (NITI-S stent; Taewoong Medical, Seoul, Korea) with a 7 Fr introducer was placed across the CBD stricture and the ampulla of Vater. The procedure was uneventful. Balloon dilation was not performed and a waist deformity of the stent remained at the stricture site (Fig. 1). An external drain was left in place for biliary lavage and follow-up cholangiography. At follow-up cholangiography 3 days later, the waist deformity of the stent remained. The stent was dilated with a 4-cm  8-mm angioplasty balloon catheter (Olbert; Medi-tech/Boston Scientific, Watertown, MA, USA) up to 12 atm of pressure. The external biliary drainage tube was removed uneventfully (Fig. 2). Two days later, the patient developed fever and abdominal pain. Upon physical examination, there were signs of peritoneal irritation, a temperature of 38.2 °C and rales on the left-lower-lung field, a WBC of 15,700/mm 3 (neutrophils 88.3%); total bilirubin 7.4 mg/dl; alkaline phosphatase 220 U/L. The next day a chest posterior-anterior radiograph showed subphrenic intraabdominal gas (Fig. 3). The abdomen remained soft. Urgent abdominal CT and endoscopic retrograde cholangiography (ERC) were performed with a suspicion of ampullary injury during stent placement or balloon dilation. On ERC, the ampulla was widely open and the stent was well positioned without evidence of contrast leakage into the peritoneal space. CT demon- strated intrahepatic pneumobilia and a large amount of air in the gall bladder (Fig. 4A); the intra-and extrahepatic bile ducts were decompressed and a fluid collection with multifocal air densities around the liver adjacent to the site of the external drainage tube removal was noted (Fig. 4B). About 10 ml of thin brownish fluid were aspirated from the right subhepatic space. The fluid was sterile. Retrospective review of the cholangiogram obtained immediately after drainage tube removal revealed contrast media leakage into the peritoneal space through the transhepatic tract (Fig. 2). We concluded that the fluid and air had indeed subsequently leaked through the transhepatic tract. A widely open ampulla of Vater might have facilitated the pneumobilia. The patient was placed on intravenous antibiotics and the symptoms subsided without secondary intervention. Discussion A number of complications of percutaneous transhepatic insertion of biliary stents have been reported: bile leakage, seeding of ma- lignant cells along the percutaneous tract, stent clogging, tumor ingrowth or overgrowth, and the complications of transpapillary placement of metallic stents. These include gastrointestinal hemor- rhage due to duodenal erosion, repeated cholangitis, duodenal ob- struction, or duodenocolic fistula due to stent migration [5– 8]. Bar-Meir et al. [9] reported a case of pneumoperitoneum fol- lowing endoscopy-guided, transpapillary insertion of a plastic stent. In their case, duodenal air passed into the CBD through the stent and leaked through a preexisting defect of the CBD into the peritoneal cavity. Thus, perforation of the bile duct, an intra- peritoneal structure, produces pneumoperitoneum. Duodenal in- Correspondence to: J.-S. Yu, M.D.; e-mail: yjsrad97@yumc.yonsei.ac.kr DOI: 10.1007/s002700010111 Cardio V ascular and Interventional Radiology © Springer-Verlag New York, Inc. 2000 Cardiovasc Intervent Radiol (2000) 23:482– 484 DOI: 10.1007/s002700010111