Retroflexion-assisted endoscopic mucosal resection: a useful and safe method for removal of low rectal laterally...

Lesions below or involving the dentate line cannot be removed by standard forward-viewing endoscopic mucosal resection (EMR). Data about retroflexion technique applied during EMR for low rectal laterally spreading tumors (LSTs) are quite limited. Therefore, we aimed to determine the efficacy and safety of retroflexion-assisted EMR (REMR) for the removal of large LSTs from the lower rectum.

EMR employing a complete retroflexion technique was performed in 49 consecutive patients (28 men, 21 women; mean age 51.8 years) with low rectal LSTs that were considered unresectable by conventional forward-viewing EMR due to the narrow and poor endoscopic view. Colonoscopy follow-up data were collected after resection.

The low rectal LSTs had a median size of 51 mm (range 30-85 mm). All the tumors were successfully resected in two sessions (median procedure time 57.4 min, range 29-126 min). Procedure-related early bleeding occurred in 14 patients, and delayed hemorrhage occurred in four patients. Serious complications such as perforation or anal dysfunction were not observed, and any procedure-related bleeding was well controlled. The median follow-up period was 8.4 months (range 3-36 months). Nine patients (nine out of 49, 18.4%) experienced recurrence based on follow-up colonoscopy examinations, and the recurrent lesion was completely eradicated by additional endoscopic treatments.

This is the first pilot study to evaluate the efficacy and safety of REMR for removal of low rectal LSTs. The short-term outcomes observed in this study indicate that REMR is a valuable method for the removal of low rectal LSTs. However, further studies evaluating the long-term efficacy and comparing REMR with other interventional therapies are needed.