S3493 Suspected Pneumoperitoneum After an ERCP

Abstract

INTRODUCTION: Endoscopic retrograde cholangiopancreatography (ERCP) continues to evolve as a diagnostic and therapeutic intervention for numerous pancreaticobiliary disorders. The incidence rate of duodenal perforation (DP) is rare (0.5 to 1%) but with high mortality (9-18%). DP is often recognized radiographically with the presence of extrabiliary free air, but it is important to differentiate from pneumobilia, the free air of no clinical significance following an ERCP. CASE DESCRIPTION/METHODS: A 73-year-old female with past medical history of hypertension, hyperlipidemia, and diabetes presented to the emergency department due to fever, weakness, and confusion for which broad spectrum intravenous antibiotics were initiated. Labs demonstrated an ALT predominated transaminitis and hyperbilirubinemia. Computed tomography (CT) scan revealed dilated biliary tree with probable common bile duct stone. Subsequent septic shock led to an emergent ERCP for suspected ascending cholangitis. Sphincterotomy released a large amount of purulent material, a 1 cm stone, and several smaller stones. Post-procedural chest x-ray was concerning for free air. A nasogastric tube was placed and chest radiograph showed signs of pneumoperitoneum re-demonstrated. Finally, abdominal CT confirmed that there was no air under the diaphragm but pneumobilia was visualized. The patient continued to improve without complications and was subsequently discharged. DISCUSSION: ERCP is a safe and effective procedure for treating many diseases of the pancreatobiliary system but is attributed to subsequent morbidity in some cases. The complications of ERCP include hemorrhage, pancreatitis, cholangitis, and duodenal perforation. After an ERCP with sphincterotomy, clinically insignificant air in the biliary tree can be apparent on CT for months or even years.Although rare, perforation of the duodenum or bile duct can occur in about 1% of ERCP and most cases demonstrate pneumoperitoneum or retropneumoperitoneum. Once radiographic imaging shows free air under the diaphragm, CT imaging should be utilized to confirm the diagnosis.If DP is suspected, management should be individualized according to the imaging findings and overall clinical picture. Patients without peritonitis, sepsis, significant contrast leak during ERCP or follow-up upper GI study, and retro- or intraperitoneal fluid collections during CT, can be successfully managed conservatively with nothing by mouth, intravenous hydration, antibiotics and nasogastric tube for decompression.Figure 1.: Apparent free air under the diaphragm.Figure 2.: Pneumobilia on Abdominal CT. No pneumoperitoneum.