Introduction

​Transanal Minimally Invasive Surgery (TAMIS) and Endoscopic Submucosal Dissection (ESD) are minimally invasive techniques for en bloc resection of large non-pedunculated rectal lesions. While TAMIS has been widely adopted in the Netherlands, ESD uptake has been slower. No randomized trials have compared these methods, leaving the choice of technique dependent on local expertise rather than evidence.

Aims & Methods

This multicenter-randomized non-inferiority trial (NTR7281) aimed at comparing TAMIS and ESD regarding effectiveness, safety, patient burden, and costs. In total, 198 patients with non-pedunculated rectal lesions >2 cm, located ≤15 cm from the anal verge, were included. Patients were randomized in a 1:1 ratio to TAMIS or ESD, with stratification by polyp size (20–40 mm or >40 mm) and distance from the dentate line (<10 mm, 10–99 mm, 100–150 mm), after an expert panel had judged the lesions suitable for inclusion. Exclusion criteria included deep submucosal invasion on endoscopy or imaging (with endoscopy prioritized in case of discordant findings), prior endoscopic resection attempt, and an unfavorable risk-benefit ratio for local treatment (e.g., poor general condition or very short life expectancy). The primary endpoint was cumulative local recurrence at 12 months (non-inferiority margin: 6%). Secondary endpoints included radical (R0) resection rate, complications (AGREE classification), patient burden (COREFO, EQ-5D-5L, QLQ-CR29), and cost-effectiveness. Intention-to-treat analysis was performed.

Results

Of the 198 randomized patients (98 TAMIS, 100 ESD), 5 crossed over from TAMIS to ESD and 1 from ESD to TAMIS. One patient dropped out before treatment as result of non-related metastatic disease. Mean polyp size was 42.0 mm. Mean procedure time was 108.7 minutes for ESD and 78.1 minutes for TAMIS. In total, 156 benign and 41 malignant lesions (39 T1, 2 T2, and 1 T3) were resected. At 12 months, 6 recurrences occurred: 0 (0%) in the ESD group and 6 (6.4%) in the TAMIS group, all benign, with a 6.4% difference favoring ESD (95% CI: -11.8 to -1.5), confirming non-inferiority and also superiority. R0 resection rates were 83% for ESD and 71% for TAMIS (p = 0.047). Overall complication rates were similar (p = 0.33). Colorectal functional outcomes at 12 months were similar and comparable to baseline. Quality-adjusted life years were also similar (0.90 for ESD and 0.91 for TAMIS, p = 0.356). Despite a significant difference in the average initial procedure cost (€2.628 for ESD and €3365 for TAMIS, p < 0.001), the average total cost over 12 months was similar (€7.134 for ESD and €7216 for TAMIS, p = 0.934).

Conclusion

This trial is the first to show that ESD is non-inferior to TAMIS for local recurrence at 12 months in en bloc resection of large non-pedunculated rectal lesions. ESD showed superior radical resection rates and lower initial procedural costs, while both techniques had similar safety profiles, colorectal functional outcomes, quality-adjusted life years, and total 12-month costs.

Disclosure

The TRIASSIC study received funding by ZonMw and Applied medical.
A. Koch received consultancy fees from Microtech, Erbe and Fujifilm