Apart from endoscopic submucosal dissection (ESD), endoscopic intermuscular dissection (EID) and exposed full-thickness resection (EFTR) extend curative endoscopic resection to the ultra-distal rectum, but multicenter outcome data are scarce. We evaluated oncological adequacy, safety and rectal preservation of a multimodal dissection strategy for malignant rectal lesions.

We analyzed a prospectively maintained database of 275 consecutive advanced endoscopic rectal resections performed in three Greek ESD referral centers (Dec-2021 to Oct-2025). All lesions classified as malignant (pT1a or more) were included. Resections were categorized as ESD or EID±EFTR. R0 required clear lateral and vertical margins. High-risk histology was defined as pT1a lesions with, lymphovascular or perineural invasion, poor differentiation or tumor budding Bd2–3 or pT1b and PT2 lesions. Primary outcomes were en-bloc and R0 resection; secondary outcomes were adverse events (AEs), local recurrence and need for radical rectal surgery (TME). Statistical analysis was performed using R Statistical Software (v4.4.1; R Core Team 2021).

Among 275 rectal resections, 46 (16.7%) malignant lesions were analyzed (ESD 30, EID±EFTR 16). EID±EFTR was mainly used for ultra-distal lesions (median distance from anal verge 10 vs 75 mm for ESD, p=0.044) with higher rates of fibrosis (57% vs 21%) and previous neoadjuvant therapy (31% vs 4.3%). Pathological staging was also more advanced in the EID±EFTR group, with a higher proportion of pT2 cancers (38% vs 6.9%). Despite this selection bias toward technically challenging lesions, en-bloc and R0 resection rates remained high at 96% and 80%, respectively, with similar R0 between ESD and EID±EFTR (86% vs 69%; p>0.2). High-risk histology was present in 31/46 (69%). AEs occurred in 5/46 (11%), all managed non-surgically. Radical surgery was required in 10/46 (22%), yielding a rectal-preservation rate of 78%. A median follow up of 14 months (IQR: 7-32) was available in 18 patients, local recurrence occurred in 3 (17%) with no significant differences in recurrence or survival outcomes between techniques. Full data are provided on Table 1.

Table 1. Baseline characteristics by type of resection

In this three-center cohort, a multimodal dissection strategy combining ESD, EID and EFTR safely extends curative intent to the ultra-distal rectum, with high R0 rates, low morbidity and >75% of rectal preservation despite a substantial burden of high-risk histology. Although the retrospective, observational design introduces expected selection bias between resection methods, these data remain particularly valuable given the scarcity of evidence.