Recurrent colorectal neoplasia at anastomotic sites after colorectal surgery poses a significant risk for subsequent cancer and is challenging to treat endoscopically due to severe fibrosis. Evidence on the feasibility of endoscopic submucosal dissection (ESD) in this setting remains limited. This study aimed to assess clinical and procedural outcomes of ESD for colorectal anastomotic-site lesions.

A retrospective analysis was conducted on 17 patients who underwent ESD for anastomotic-site lesions at two high-volume western referral centers between January 2018 and June 2025. Tumor characteristics (location, morphology, size, histology, invasion depth) and procedural outcomes (technical success, en bloc and R0 resection rates, procedure time, and adverse events) were evaluated.

Mean patient age was 62 years (range 41–84); six patients had hereditary syndromes (Lynch n=3; FAP n=3). Lesions occurred at ileocolic (n=1), colocolic (n=3), colorectal (n=8), coloanal (n=1) anastomoses, and in the ileal pouch (n=4). Median tumor size was 38 mm. Morphology included three protruded lesions, nine granular, and five non-granular LSTs. Technical success was 82% (14/17): two procedures were aborted due to severe fibrosis (both in the ileal pouch), and one lesion in the rectal cul-de-sac was inaccessible. Histology showed adenomas (LGD n=4; HGD n=7) and invasive cancer (n=3). Median procedure time was 75 minutes. En bloc and R0 resection rates were 85.7% and 71.4%, respectively. One perforation occurred during one of the aborted procedure.

ESD for colorectal anastomotic-site lesions is feasible, achieving high en bloc resection rates with acceptable safety despite technical difficulty from dense fibrosis. Ileal pouch lesions represent the most challenging subgroup. ESD may serve as an effective organ-preserving alternative to repeat surgery in selected patients.