Multiple pancreaticobiliary fistulas combined with acute necrotizing pancreatitis: a rare complication of pancreatic extracorporeal shock wave lithotripsy

A 54-year-old woman with a history of chronic pancreatitis and cholecystectomy 4 years prior presented with intermittent abdominal pain. Computed tomography (CT) revealed large pancreatic calcifications, main pancreatic duct (MPD) dilation, and pneumatosis in the bile and pancreatic ducts ([Fig. 1]). She underwent pancreatic extracorporeal shock wave lithotripsy (ESWL) first, during which small stone fragments were expelled ([Fig. 2]). However, her abdominal pain worsened, with low grade fever post-procedure. Laboratory tests and CT revealed acute necrotizing pancreatitis, extensive exudation and peripancreatic fluid collection, and impacted stones in the pancreatic head ([Fig. 3]). Abdominal pain control proved difficult without analgesics. Enhanced CT suspected a connection between the MPD and the common bile duct (CBD) ([Fig. 3], arrow). Further endoscopic retrograde cholangiopancreatography found two fistula openings near the major papilla, which proved to be bile and pancreatic duodenal fistulas. Pancreatography confirmed the presence of a pancreaticobiliary fistula, linking the distal CBD to the MPD ([Fig. 4], [Video 1]). After clearing fragments, a 7-Fr × 9-cm single-pigtail plastic stent was placed and significantly improved her symptoms.