Risk of Rectal Neoplasia after Colectomy and Ileorectal Anastomosis for Ulcerative Colitis.

Background And Aims: Colectomy can be required in the management of ulcerative colitis [UC]. While ileal-pouch anal anastomosis [IPAA] is the recommended reconstruction technique, ileorectal anastomosis [IRA] is still performed and might present some advantages. However, the risk of rectal neoplasia might limit its indication. The aims of our study were to determine the incidence of rectal neoplasias following IRA for UC and to identify risk factors associated with rectal carcinomas.

Methods: We performed a multicenter retrospective study including patients who underwent IRA for UC from 1960 to 2014 in 13 centers. Cox-proportional hazard models were used to determine carcinoma-associated risk factors.

Results: A total of 343 patients were included, with a median follow-up of 10.4 years after IRA. At the end of follow-up, 38 rectal neoplasias (including 19 carcinomas) were diagnosed, and 7 patients [2%] had either died from rectal carcinoma or had a metastatic disease. Incidences of rectal carcinoma after IRA for UC were estimated at 3.2% at 10 years and at 7.3% at 20 years, whereas incidences of neoplasia were estimated at 7.1% and 14% at 10 and 20 years, respectively. In multivariate analysis, age at IRA, IBD duration, primary sclerosing cholangitis [PSC] and history of prior colonic carcinoma were independently associated with the risk of rectal carcinoma following IRA.

Conclusion: The risk of rectal carcinoma in patients with IRA for UC remains, and this justifies long-term endoscopic surveillance. Either IPAA or end ileostomy should be considered in 'high-risk' patients i.e. those with PSC and/or with prior colonic neoplasia.