Spontaneous Pneumothorax and Pneumoperitoneum Complicating an Endoscopic Retrograde Cholangiopancreatography with Stent Exchange

Abstract

A 51 year old male, heavy smoker, presented for biliary stent removal. Two months earlier, he developed abdominal pain, weight loss and abnormal biochemical profile. A magnetic resonance cholangiopancreatography (MRCP) demonstrated a common hepatic duct stricture. He underwent an ERCP with sphincterotomy, stricture brushings and biliary stent placement. The follow-up ERCP was performed in the same fashion with intravenous propofol, meperidine and midazolam sedation. The patient was maintained in sedation in the prone position while breathing spontaneously using supplemental nasal cannula. The previously placed biliary stent was removed without complication. No sphincterotomy or other therapy was performed. Well into the procedure, the patient developed hypoxia with his O2 saturation decreasing to 60% on 3L/min of oxygen via nasal cannula. The oxygen flow rate was increased to 10L/min, the propofol infusion stopped and the patient's hypoxia improved with a rise in O2 saturation to 93%. The procedure was completed. The patient was found to have a markedly distended abdomen with diffuse tenderness and crepitus extending from his chest to his neck. X-rays revealed extensive subcutaneous emphysema, a large left sided pneumothorax and free air in the abdomen. A chest tube was placed into the patient's left hemithorax, and an upper gastrointestinal series, and computer assisted tomography scan was performed using gastrograffin contrast. Despite the findings of a large amount of pneumoperitoneum, pneumoretroperitoneum, pneumothorax and penumomediastinum, there was no extravastion of contrast material. An emergency laparotomy was performed. Despite the presence of retroperitoneal air, there was no perforation and no evidence of intestinal content leakage. Examination of the lesser sac and the esophagogastric junction was negative. His post-operative course was unremarkable and he was discharged home in the fifth post operative day. Since the laparatomy failed to demonstrate perforation and the patient improved with chest tube insertion, we hypothesize that this heavy smoker developed a pneumothorax during the ERCP as a result of a ruptured sub-pleural bleb. A large amount of air dissected through the mediastinum into the retroperitoneal and peritoneal spaces during endoscopy. Although the risk of pneumothorax is very small and it is a rare cause of pneumoperitoneum, recognizing it may save patients unnecessary surgery.