The role of peroral video cholangioscopy in patients with IgG4-related sclerosing cholangitis

Background The cholangioscopic features of IgG4-related sclerosing cholangitis (IgG4-SC) remain undefined. The aim of this study was to clarify these endoscopic features using peroral video cholangioscopy (PVCS) in IgG4-SC patients. Methods PVCS was performed in 33 patients: IgG4-SC (n = 13); primary sclerosing cholangitis (PSC; n = 5); and cholangiocarcinoma (n = 15), which included hilar cholangiocarcinoma (HCCA; n = 5) and distal cholangiocarcinoma (DCCA; n = 10). Results The most frequent findings on PVCS in the IgG4- SC patients were dilated (62 %) and tortuous (69 %) vessels, and absence of partially enlarged vessels. The incidence of dilated and tortuous vessels was significantly higher in IgG4-SC patients than in PSC patients (p = 0.015). Scarring and pseudodiverticula were found significantly more often in PSC patients than in IgG4-SC patients (p = 0.001 and p = 0.0007, respectively). The incidence of partially enlarged vessels was significantly higher in DCCA patients than in IgG4-SC patients (p = 0.004). In contrast, the incidence of dilated vessels was significantly higher in IgG4-SC patients than in HCCA patients (p = 0.015). PVCS performed after corticosteroid therapy showed resolution of bile duct stenosis and dilated, tortuous, or partially enlarged vessels, as well as resolution of friability in all patients with IgG4-SC. Conclusion Cholangioscopy was useful in differentiating IgG4-SC from PSC. In addition, monitoring the patterns of proliferative vessels on PVCS may be useful to differentiate IgG4-SC from cholangiocarcinoma.