P115 Chronic pouchitis and Crohn’s disease of the pouch after ileal pouch-anal anastomosis: incidence and risk factors

Abstract

Abstract Background Restorative proctocolectomy with ileal-pouch anal-anastomosis (IPAA) is the operation of choice for patients with ulcerative colitis (UC) or with inflammatory bowel diseases unclassified (IBDU) who had failed medical treatment or with colon dysplasia. The aim of our study was to assess the incidence and risk factors of chronic pouchitis (CP) and Crohn’s disease of the pouch (CDP). Methods We conducted a retrospective study among five tertiary referral hospitals. All patients older than 15 years of age with UC or IBDU who underwent IPAA between January, 2011 and December, 2019, were included. Patients with no ileostomy closure or with a follow-up of less than 2 months after ileostomy closure were excluded. The main outcome was the occurrence of CP or CDP. Patients’ demographic, clinical and endoscopic characteristics were collected from medical records at the time of surgery. We looked for risk factors with multivariable and a least absolute shrinkage and selection operator (LASSO) Cox models. Results 247 patients were included. The median follow-up was 3.1 years (IQR: 1.1–5.7). The incidence rate of CDP was 7.9% (95%CI: 3.9–11.8) two years after IPAA and 18.3% (95%CI: 11.0–25.0), five years after IPAA. The incidence rate of CP was 7.6% (95%CI: 3.8–11.3) two years after IPAA and 19.5% (95%CI: 12.2–26.2), five years after IPAA. The incidence rate of either CP or CDP was 15.6% (95%CI: 10.2–20.7) two years after IPAA and 35.3% (95%CI: 26.2–43.2), five years after IPAA. In multivariable analysis, diagnosis of IBDU (HR 3.18; 95%CI: 1.77–5.70; p<0.001), age of less than 35 years at surgery (HR 2.03; 95%CI: 1.20–3.43; p=0.008) and extra-intestinal manifestations other than articular and primary sclerosing cholangitis (HR 4.37; 95%CI: 2.12–9.02; p<0.001) were associated with higher incidence of either CP or CDP. The LASSO analysis identified these three prognostic factors and also articular manifestations. In patients with two or more prognostic factors, the 5-year cumulative incidence of CP or CDP, was 65.2% (95%CI: 41.8–79.2). It was 18.6% (95%CI: 7.1–28.6) in patients with none. Conclusion Five years after IPAA, approximately one-third of patients had either CP or CDP. Risk factors were IBDU, an age of less than 35 years at surgery, articular manifestations and other extra-intestinal manifestations, excluding primary sclerosing cholangitis. These results suggest that high-risk patients might benefit from scheduled endoscopies of the pouch and/or postoperative medical therapy to limit pouch damages.