Small-duct primary sclerosing cholangitis: a long-term follow-up study.

Some patients with inflammatory bowel disease (IBD) have chronic cholestasis and hepatic histology compatible with primary sclerosing cholangitis (PSC) but normal findings on cholangiography. These patients with small-duct PSC have remained largely unstudied. Our aim was to determine the prevalence and long-term outcomes of patients with small-duct PSC. Eighteen patients with small-duct PSC (7 female and 11 male patients; mean age, 39.9 +/- 15.3 years [range, 13-68 years]) seen over a 4-year period were matched blindly by age and sex to 36 patients with classic PSC and followed up for 32.5 years. Small-duct PSC represented 5.8% of patients (18 of 309) with sclerosing cholangitis. Subsequent endoscopic retrograde cholangiography (ERC) performed in 5 patients with small-duct PSC showed progression to typical PSC in 3 patients at 4, 5.5, and 21 years of follow-up. None of the patients with small-duct PSC but 4 of the patients with classic PSC developed hepatobiliary malignancy. There were 3 deaths (17%) or liver transplantations in patients with small-duct PSC (2 after progressing to classic PSC) and 15 (42%) in the classic PSC group. Survival free of liver transplantation was significantly greater in the small-duct than in the classic PSC group (P =.04). Compared with the general U.S. population, survival in patients with small-duct PSC was similar (P =.4) but significantly lower in patients with classic PSC (P <.001). In conclusion, small-duct PSC may represent an earlier stage of PSC associated with a significantly better long-term prognosis. Some patients, however, progress to classic PSC and/or end-stage liver disease with the consequent necessity of liver transplantation.