S51 Prevalence of Undiagnosed Dysplasia in Patients With Ulcerative Colitis Prior to Ileal-Pouch Anal Anastomosis

Abstract

Background: Ileal pouch-anal anastomosis (IPAA) has been the procedure of choice for patients with refractory ulcerative colitis (UC) or those at high-risk for dysplasia. Given that patients with UC are at increased risk for colorectal cancer, detection of dysplasia is essential to determine the best next step regarding treatment. In this study, we aim to assess the prevalence of dysplasia prior to IPAA and compare it to that found in the colectomy specimen in a Puerto Rican cohort. Methods: We retrospectively reviewed pouchoscopy reports and medical records from patients with UC who have had IPAA at a tertiary care center for IBD between 1990 and 2018. Data collected included dates of diagnosis, colectomy and pouch becoming functional, along with the indication for colectomy, surgical specimen pathology, and the type of pouch. Descriptive and bivariate analyses were executed. This study is approved by the UPR-MSC IRB. Results: A total of 93 patients with IPAA were identified, 48 females and 45 males, with a mean age of 40.04±14.29 years. Forty-nine percent were over 40 years old at the time of surgery. All patients had a J-shaped pouch. The ​average time interval from date of diagnosis to colectomy was 7.35 years. When assessing the indication for colectomy, 86% were referred for severe UC, 12% for dysplasia, and 2% for other reasons, such as fulminant colitis. After pathological examination of the surgical specimen, 22% had dysplasia. Of the 20 patients who had dysplasia, 55% had severe UC as indication for colectomy. There was no significant difference in prevalence of dysplasia between patients over 40 and those ages 40 or less (P=0.5761). There was also no significant difference when comparing sex and the presence of dysplasia (P=0.2408). The average time between date of diagnosis to a functioning pouch in 19 patients with dysplasia was 8.42 years, with a range of 1 year to 31 years. Conclusion(s): The majority of patients had IPAA due to severe UC; however, dysplasia was found almost equally in those whose indication for colectomy was due to severe UC without a pre-operative diagnosis of dysplasia. One possible explanation may be the difficulty of diagnosing dysplasia in the presence of inflammation. Additionally, the finding of severe UC in colonoscopy may deter the performance of random surveillance biopsies. If these findings are confirmed, serious consideration of a total colectomy versus continuation of pharmacologic treatment in refractory patients is warranted. Moreover, even though guidelines recommend surveillance colonoscopy starting at 8 years after diagnosis of UC, some of our patients demonstrated dysplasia earlier. Prior undiagnosed UC could be one explanation, but the finding warrants further study.