Smooth Muscle Distribution Patterns of Choledochal Cysts and Their Implications for Pathogenesis and Postoperative Complications

Abstract Objectives Histopathologic characteristics of choledochal cysts and their clinical implications have not been previously comprehensively studied. Methods Smooth muscle distribution patterns and other histologic findings (inflammation, metaplasia, dysplasia, and heterotopia) in 233 surgically resected choledochal cysts were evaluated. Results Mean patient age was 23.3 ± 19.8 years, with male:female ratio of 0.3. Most cases were Todani type I (175 cases, 75.1%) or IVa (56 cases, 24.1%). Choledochal cysts with thin scattered/no muscle fiber (175 cases, 75.1%) were the predominant pattern and were associated with more frequent postoperative biliary stricture (P = .031), less frequent pyloric metaplasia (P = .016), and mucosal smooth muscle aggregates (P