Pouch excision, dysplasia and polypectomy in familial adenomatous polyposis ileal pouch anal anastomosis: a retrospective analysis.

[INTRODUCTION] Familial adenomatous polyposis (FAP) is a rare autosomal dominant syndrome that, if untreated, carries a 100% lifetime risk of developing colorectal cancer. Proctocolectomy with ileal pouch-anal anastomosis (IPAA) is a surgical approach for FAP management, but data on long-term outcomes remain limited. This study aimed to assess IPAA-associated pouch excision, dysplasia, polyp management and pouchitis in patients with FAP post IPAA.

[METHODS] Single-centre retrospective review of patients with FAP with IPAA at a tertiary referral centre. Data on demographics, pouch excision, endoscopic and histopathological records were collected. Statistical analysis was performed using Excel and GraphPad.

[RESULTS] Forty patients with FAP with IPAA were included. The median age was 48 years (IQR 33-58.5), with a median age of 22 years at pouch formation (IQR 18-30.5) and a median pouch age of 217 months (IQR 143-279). A total of 230 lower gastrointestinal endoscopies were assessed. Low-grade dysplasia was identified in 70 endoscopies, and polyps in 82, with the pouch being the most common site. One case of rectal adenocarcinoma was identified, with no cases of high-grade dysplasia. There were 35 episodes involving polypectomy, with cold snare being the most common method (50%). Endoscopic management had a lower complication rate than surgical management (p=0.0474). Eight (20%) patients underwent pouch excision, with poor function being as common as pouch-related complications (37.5%), with a median pouch age at excision of 167 months (IQR 115.5-286.5). Endoscopic pouchitis was significantly more common in those who underwent pouch excision (p=0.0231).

[CONCLUSION] Patients with FAP and IPAA require surveillance due to a high incidence of dysplasia and polyp formation, although malignancy remains rare. There is a significant rate of pouch excision, for which pouchitis appears to be a risk factor. Early and aggressive endoscopic management of polyps is recommended to prevent advanced disease and minimise complications associated with surgical approaches.