Clinical features and management of painless biliary type sphincter of Oddi dysfunction

OBJECTIVE: The objective of this study was to clarify the characteristics and management of painless biliary type sphincter of Oddi dysfunction (SOD). METHODS: From June 2002 to July 2018, 12 patients who had recurrent liver dysfunction with a dilated bile duct or acute cholestasis of unknown cause without biliary pain (painless SOD) were included in this study. These patients’ characteristics were compared with those of 36 patients with biliary type SOD based on the conventional definition (criteria-based SOD). RESULTS: Patients with painless SOD had significantly more prominent bile duct dilation than patients with criteria-based SOD (13.9 vs. 12.2 mm, respectively). Prophylactic biliary drainage was performed significantly more often in patients with painless SOD than criteria-based SOD (67% vs. 11%, respectively). The short-term effectiveness rate of endoscopic sphincterotomy, the symptom recurrence rate, and the incidence of adverse events were not significantly different between the two groups. CONCLUSIONS: Painless SOD is a specific subtype of biliary SOD that causes recurring liver dysfunction or acute cholestasis without biliary pain. Endoscopic sphincterotomy was effective in the present study, but the relapse rate was as high as that in typical SOD.