Incomplete resection of colorectal polyps predisposes to local recurrence and technical difficulty in subsequent interventions. Prior resection attempts create fibrosis in the submucosal space, limiting lifting and snare capture, and may necessitate advanced techniques. Real-world data comparing outcomes for incompletely resected versus naive lesions are limited, particularly within an “all-comers” unselected referral population. Our aim was to compare procedural success, safety, and recurrence between previously incompletely resected and naive complex colorectal lesions, and to describe the efficacy of advanced resection and adjunctive techniques for previously resected lesions.

All consecutive patients who underwent resection of complex colorectal polyps at St. Michael’s Hospital, Toronto, Canada, between 2019 and 2025 were included. Prior resection was defined as any lesion with a prior incomplete resection (not including biopsy or tattoo) attempt identified endoscopically and/or through referral chart review. 

Among 1,546 lesions, 1,359 had no prior resection and 187 had prior incomplete resection. In the no prior resection group, 86.5% were treated with EMR, 2.7% with hybrid EMR and 10.8% with ESD, whereas in the prior incomplete resection group 69.5% underwent EMR, 11.8% hybrid EMR and 18.7% with ESD. When EMR was performed in the no prior resection group, en-bloc EMR was performed 10.1% of the time, hot-snare piecemeal EMR in 65.3%, cold-snare piecemeal EMR in 11.0%,, compared with 3.2%, 57.8%, and 8.6% respectively in the prior incomplete resection group (p<0.0001). Adjunctive methods were required more in the prior incomplete resection group. CAST was used in 31.0% vs 43.9% (p=0.0004), hot avulsion in 5.8% vs 20.3% (p<0.0001), and submucosal release in 8.0% vs 40.1% (p<0.0001). Technical success was achieved in 95.8% vs 97.9% (p=0.18) in the no prior resection versus prior incomplete resection groups. For adverse events, intra-procedural perforation occurred in 0.8% vs 1.1% (p=0.38), delayed bleeding in 2.2% vs 1.6% (p=0.59), and delayed perforation in 0.4% vs 0% (p=0.36) in the no prior resection versus prior incomplete resection groups. Recurrence at first surveillance was 9.2% vs 13.1% in the no prior resection versus prior incomplete resection groups (p=0.25).

Lesions with prior incomplete resection were associated with markedly greater technical complexity, reflected by increased use of advanced and adjunctive techniques. Despite this, technical success, curative resection, adverse events, and early recurrence were similar between groups. In contrast to prior literature [1], when adjunctive therapy consisted almost exclusively of CAST/hot avulsion and outcomes for previously attempted lesions were inferior, a more nuanced and deliberately aggressive adjunctive strategy can largely overcome the historical disadvantage of previously manipulated, fibrotic colorectal lesions.