Double gallbladder malformation with duodenal ulcer stricture leading to common bile duct dilation: a case report.

Anatomical variants of the biliary system, such as a double gallbladder, are rare congenital anomalies. Although benign strictures of the duodenal bulb are common, their role as a long-term, subtle cause of biliary obstruction leading to complex pathological changes is rarely reported. This case report presents a complicated case in which a duodenal ulcer-related stricture caused chronic biliary obstruction, leading to cholestasis, dilation of the common bile duct (choledochectasia), and gallstone formation. These processes were further complicated by the presence of a double gallbladder anomaly, eventually requiring surgery. A 56-year-old male was admitted for abdominal pain. His medical history included right-sided nephrectomy, a duodenal ulcer, and previous embolization for duodenal hemorrhage. Imaging studies revealed gastric retention, significant dilation of intrahepatic and extrahepatic bile ducts accompanied by pneumobilia, and an incidental finding of a double gallbladder anomaly. One gallbladder exhibited evidence of cholestasis, while the other was impacted with stones. Gastroscopy confirmed a sever narrowing of the duodenal bulb. After failed conservative management, a multidisciplinary team performed a distal gastrectomy (Billroth II), double cholecystectomy, and choledochotomy with T-tube drainage. Surgical exploration confirmed a fibrotic duodenal stricture and sludge-filled gallbladders. The patient recovered uneventfully. This case illustrates that benign duodenal strictures can lead to chronic biliary obstruction, a process significantly aggravated by anatomical variants. This report emphasizes that unexplained biliary dilation accompanied by cholestatic laboratory findings should include proximal obstructive lesions, particularly duodenal bulb strictures, in the differential diagnosis. When such lesions coexist with rare anatomical variants like a double gallbladder, a complex pathological loop forms. Multidisciplinary, definitive surgery is often the solution when conservative therapy fails, offering new insights into the interaction between the upper and biliary digestive systems.