Background: Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) have an increased risk of colorectal neoplasia compared to patients with IBD alone. Data on risk of pouch-related dysplasia following total proctocolectomy with ileo-anal anastomosis (IPAA) in this high-risk group are scarce. Nevertheless, some authors recommend yearly surveillance pouchoscopies. Our aim was to describe the incidence of pouch dysplasia in IBD-PSC patients after IPAA.
Methods: This is a retrospective analysis of all IBD-PSC patients who underwent IPAA with subsequent surveillance pouchoscopies between 2005–2015 at a single tertiary IBD referral center. Patient demographics, indication for IPAA, as well as gross and histologic findings on pouchoscopy were recorded.
Results: Among 156 patients with IBD-PSC, 18 (16 with ulcerative colitis and 2 with Crohn's disease) underwent IPAA, with a mean follow-up of 3 years. Mean ages for IBD and PSC diagnosis were 25±11 and 34±13 years, respectively; 89% were men. Sixty-seven percent of patients had exposure to ursodeoxycholic acid (UDCA). Indications for IPAA included: refractory colitis (61%, n=11), advanced colorectal neoplasia (aCRN: high-grade dysplasia or cancer) (22%, n=4), and low-grade dysplasia (17%, n=3). Median number of pouchoscopies per patient was 2 (range 1–10). Histologic evidence of chronic pouchitis was present in all cases. During follow-up 11% of patients (n=2) developed dysplasia: 1 case of unifocal indefinite dysplasia of the pouch and 1 case of multifocal high-grade dysplasia of the pouch and rectal cuff. Median time between IPAA and dysplasia development was 7 years (range 1–13). Both patients had undergone IPAA for aCRN, had persistent chronic pouchitis and UDCA exposure. Having aCRN as the indication for IPAA was significantly associated with development of pouch dysplasia (p=0.04). The cumulative incidence of pouch dysplasia was 5.6% at 1 year and 30% at 13 years after IPAA overall, while the cumulative incidence of pouch dysplasia in patients undergoing IPAA for any aCRN was 25% at 1 year and 63% at 13 years (p=0.049 log-rank test; vs other indications for IPAA).
Conclusions: In this relatively small single-center cohort there seems to be a high risk of pouch dysplasia in IBD-PSC patients following IPAA, especially if the indication for IPAA was aCRN. As we await validation of our findings for this high-risk subset of patients, pouch surveillance appears to be justifiable. Larger, multi-center prospective studies with longer follow-up are needed.