Transanal NOTES total mesorectal excision (TME) in patients with rectal cancer: Is anatomy better preserved?

Natural orifice transluminal endoscopic surgery (NOTES) and single-incision laparoscopy are spreading worldwide. Total mesorectal excision (TME), the standard treatment for patients with distal rectal tumors, is usually performed in an “up-to-down” approach, either laparoscopically (_LAPTME) or as an open procedure. We have already reported a NOTES-inspired, transanal, “down-to-up” variant of TME (_NOTESTME). The main aim of this study was to assess the quality of the resected specimen in patients who had undergone either _NOTESTME or _LAPTME.

All patients with distal rectal neoplasia presenting between January 2011 and December 2014 were considered for the study. Additional inclusion criteria comprised American Society of Anesthesiologists score ≤ III and the absence of previous open surgery. Assignment to either group was sequential and based on the rank of inclusion in the study. The primary endpoint was the macroscopic quality of the specimen. Secondary endpoints included nerve visualization, tumor perforation, operating time, status of margins, and number of retrieved nodes.

Eighteen patients (6 men, 12 women) were in the _NOTESTME group and 15 (7 men, 8 women) in the _LAPTME group, respectively. The TME specimen was considered complete or mainly regular in 16 patients who had undergone _NOTESTME (88.9 %) and in 11 patients who had undergone _LAPTME (73.3 %), (p > 0.05). During the procedure, we visually identified the neurovascular bundles of Walsh in 14 patients in the _NOTESTME group (77.8 %) and in only 5 patients in the _LAPTME group (33.3 %), (p < 0.05). Mean operative time was 245 min (range 155–440 min) in the _NOTESTME group and 275 min (range 180–400 min) in the _LAPTME group (p > 0.05). A median of 11 nodes per specimen (range 8–22 nodes) was retrieved in the _NOTESTME group and 12 nodes (range 6–41 nodes) in the _LAPTME group, respectively (p > 0.05). Distal and radial margins were comparable in both groups.

Compared to the _LAPTME, the _NOTESTME seems to be associated with a more frequent intraoperative identification of the sacral nerves. However, the difference in overall quality of the retrieved specimen, although favoring _NOTESTME, did not reach statistical significance in this small series.