P-160 YI Preoperative Anti-TNFα Therapy Is Associated with Increased Incidence and Shorter Interval to De Novo Crohnʼs Disease After Ileal-Pouch Anal Anastomosis (2013)

Crohn’s disease of the pouch (CD) occurs in up to 18% of patients after ileal pouch-anal anastomosis (IPAA). At our institution, we have recently noticed an increased incidence of de novo CD after IPAA. We aimed to determine if preoperative anti-TNFα drug use is associated with increased incidence or shorter interval to development of de novo CD after IPAA. A single institution, prospectively maintained database was examined for patients who underwent IPAA for ulcerative colitis (UC) or inflammatory bowel disease-unclassified (IBDU) over a 20-year period ending February 2013. The development of CD of the pouch, anti-TNFα drug use prior to surgery, demographic and disease characteristics were tabulated. Univariate analysis was performed to evaluate associations between CD of the pouch and potential risk factors. Factors with P < 0.2 were included in our multivariable analysis with P < 0.05 considered statistically significant. The entire cohort was also divided into 3 groups chronologically based on date of stoma closure: Group 1(1993 to 1999); Group 2 (2000 to 2006); Group 3 (2007 to 2013). Patients who developed de novo CD were evaluated for anti-TNFα drug use and time to the diagnosis of de novo CD. The 462 study patients had a mean age (±SD) of 39 ± 16 years and 53% were male. Three hundred eleven (67%) patients underwent surgery for UC and 151 (33%) for IBDU. Over a median follow-up period (IQ range) of 99 (93) months, 74 patients (16%) developed de novo CD (p = NS between Groups 1, 2, and 3). Preoperative anti-TNFα was administered in 34% (157/462) of the patients in the entire study cohort, none of the 90 patients in Group 1, 24% (49/203) of the patients in Group 2 and 64% (108/169) of the patients in Group 3 (P < 0.001). Univariate analysis identified mean age at surgery (P = 0.02), mean age at disease onset (P = 0.02), smoking history (P = 0.18), preoperative disease classification of IBDU (P = 0.009), preoperative anti-TNFα drug use (P = 0.04) and the development of pouchitis (P < 0.001) as potential risk factors for de novo CD. Multivariable analysis identified 2 factors independently associated with de novo CD; anti-TNFα drug use (OR 2.2; (95% CI) 1.3–3.9; P = 0.004) and development of pouchitis (OR 7.8; (95% CI) 4.3–14.3); P < 0.001). Median time to diagnosis of CD (IQR) for patients treated and not treated with anti-TNFα drugs prior to surgery was 6.5 (12) months and 24 (62) months respectively (P < 0.001) (Fig. 1). Median time to CD (IQR) for Group 1 patients was 42 (156) months, for Group 2 patients was 38 (62) months, and for Group 3 patients was 5 months (5); P < 0.001 (Fig. 2). Treatment of patients with UC and IBDU with anti-TNFα drugs prior to IPAA is increasing. Patients treated with anti-TNFα drugs prior to IPAA appear to have an increased risk and shorter time to development of de novo CD after surgery. This may be a reflection of referral center bias, more aggressive disease process in patients treated with anti-TNFα drug preoperatively or the ability of anti-TNFα drugs to mask CD prior to IPAA.