Global 
Deutschland Colon to Rectum
Gastroenterology. 2026;170(1):161-173
A randomized trial of endoscopic submucosal dissection vs. transanal minimally invasive surgery in early rectal neoplasms: DSETAMIS-2018 study
Background and aims: The optimal approach for the local resection of early rectal neoplasms (ERNs) remains debated, with limited data comparing transanal minimally invasive surgery (TAMIS) and endoscopic submucosal dissection (ESD).
Methods: A multicenter, randomized, open-label, noninferiority trial was conducted in 3 Spanish tertiary centers. Patients with nonpedunculated ERNs > 20 mm and ≤ cT1N0 were randomized to TAMIS or ESD. The primary outcome was 12-month recurrence (noninferiority margin, 10%). Secondary outcomes included technical success, en bloc, R0, and curative resection rates, procedure time, hospital stay, complications, and costs. Analyses followed intention-to-treat and per-protocol (PP) principles.
Results: Of 185 evaluated patients, 73 were randomized (34 TAMIS, 39 ESD) and 66 (90.4%) completed follow-up. Local recurrence occurred in 2 TAMIS patients and none in ESD. The 12-month recurrence risk difference was -6.7% (90% confidence interval [CI]: -14.2 to 0.8) in intention-to-treat and -8.3% (90% CI: -17.6 to 0.9) in PP analysis. ESD demonstrated shorter hospital stays (1 vs. 2 days) and higher technical success (100% vs. 88.9%; PP). No significant differences were observed in overall complications. Estimated overall costs were €11,289.27 for TAMIS vs. €6167.14 for ESD. Of the 112 off-study cases, 108 (96.4%) were successfully treated with ESD.
Conclusions: ESD appears to be noninferior to TAMIS for local resection of ERNs regarding 12-month recurrence. Both show favorable safety profiles. ESD was associated with fewer technical constraints, higher procedural success, shorter hospitalization, lower cost, and greater patient acceptance. These results should be interpreted considering the wide noninferiority margin, limited sample size, and absence of multiplicity adjustment.