DOP14 Proctocolectomy is associated with improved transplant-free survival in patients with primary sclerosing cholangitis: results from a pooled collaborative international study

Abstract

Abstract Background It is hypothesized that the gut-liver axis plays a pivotal role in the aetiology of primary sclerosing cholangitis (PSC). Colectomy before liver transplantation is associated with decreased rates of recurrent PSC.1 We previously observed that proctocolectomy with permanent ileostomy is associated with better transplant-free survival in a population-based Dutch cohort.2 The aim of the present study is to confirm the effect of colectomy on PSC disease course in an international context. Methods We conducted a retrospective analysis on the International PSC Registry (IPSCR), comprising patients from Finland, Norway, Sweden, and the Netherlands. Endpoints were defined as liver transplantation (LT) and PSC-related death (excluding colorectal carcinoma) and were censored in the first year after colectomy to allow for a delayed protective effect. Cox proportional hazards regression was performed, with correction for the following known risk factors; sex, age at diagnosis, large or small duct PSC, features of auto-immune hepatitis, and inflammatory bowel disease (IBD) status (i.e. ulcerative colitis, Crohn’s disease or IBD unspecified). IBD status and colectomy status were included as time-dependent exposure variables, the latter stratified for extent and indication for colectomy. Results A total of 2595 patients were included, of which 1341 from the Netherlands, 560 from Finland, 528 from Norway, and 166 from Sweden. Of all patients 1900(73%) were diagnosed with IBD and 346(15%) had undergone a colectomy; 34(9%) hemi-, 91(26%) subtotal, and 172(50%) proctocolectomy with pouch and 65(19%) with ileostomy. During a total follow-up of 28,282 patient years, 848(33%) patients reached the endpoint LT or PSC-related death. Hazard ratio (HR) of reaching LT or PSC-related death was significantly decreased in patients with proctocolectomy (0.70(0.52-0.93)) compared to patients without colectomy with variation per country (Netherlands 0.82(0.56-1.19), Finland 0.52(0.24-1.13), Norway 0.59(0.31-1.03), Sweden 0.28(0.06-1.24)). This effect was less pronounced in case of a hemi- or subtotal colectomy (HR 0.84(059-1.20)). The effect was most pronounced in the proctocolectomy with permanent ileostomy group (HR 0.55(0.30-0.99)). Of the known risk factors only a concurrent IBD diagnosis had no significant effect on transplant-free survival. Conclusion Our extended data confirm that colectomy is associated with a decreased risk of liver transplantation and PSC-related death. An incremental effect was seen with the extent of the colectomy, with the most pronounced effect in the proctocolectomy group with permanent ileostomy. Our data support the putative role of the gut-liver axis in the disease course of PSC.