Endoscopic mucosal resection vs transanal endoscopic microsurgery for the treatment of large rectal adenomas

Aim Large (> 2 cm) rectal adenomas are currently treated by transanal endoscopic microsurgery (TEM) or piecemeal endoscopic mucosal resection (EMR). The potential lower morbidity of EMR becomes irrelevant if it is less effective. We aimed to compare the safety and effectiveness of EMR and TEM for large rectal adenomas. Method Data from patients undergoing TEM or EMR for a rectal adenoma > 2 cm in eight hospitals were retrospectively collected. Patient‐ and procedure‐related characteristics, complications and recurrences were recorded. As EMR may require several attempts to achieve complete resection, early (after a single intervention) and late (permitting re‐treatment for residual adenoma within 6 months) recurrence rates were determined. Results Two hundred and ninety‐two (292) patients (49% male; mean age 67 years) were included; 219 were treated by TEM and 73 by EMR. Adenomas treated by EMR were smaller (median 30 vs 40 mm; P = 0.007). Perioperative complication rates were 2% for TEM and 6% for EMR (P = 0.171). Postoperative complications occurred in 24% of TEM patients and in 13% of EMR patients (P = 0.038). Median hospitalization after TEM was 3 days vs 0 days after EMR (P < 0.001). Median follow‐up was 12.6 months (0–47 months); Early recurrence rates were 10.2% in TEM patients and 31.0% in EMR patients (P < 0.001); late recurrence rates were 9.6% and 13.8%, respectively (P = 0.386). Conclusion After a single intervention, EMR of large rectal adenomas seems less effective, but safer than TEM. When allowing re‐treatment of residual adenoma within 6 months, EMR and TEM seem equally effective. A prospective randomized comparison seems to be necessary.