Robotic total mesorectal excision for rectal cancer based on the theory of fundamental use of surgical energy

Abstract

Background: Improving oncological curability and preserving urinary function must be established in robotic total mesorectal excision (TME) for rectal cancer. To achieve this, it is important to avoid nerve injury by sharp dissection of the avascular plane by the monopolar device and thermal spread. The aim of this study was to improve the robotic TME quality by focusing on the theory of fundamental use of surgical energy (FUSE) of the monopolar device and investigating the surgical procedure.

Methods: In this single-center retrospective study, 26 consecutive patients who underwent robotic TME for rectal cancer at Tokyo Medical University Hospital between June 2022 and August 2022 were included. All surgeries were performed by FUSE-certified surgeons in accordance with FUSE theory, which was, thermal effect = current density (current/area) squared × tissue resistance × contact time.

Result: The median age of the patients was 64 years (range 40-79 years), and 17 patients were male. The median operative time was 287 min (range 229-430 min); median bleeding volume, 22 ml (range 5-223 ml); and the median number of harvested lymph nodes, 17 (range 4-40). The conversion rate to open surgery was 0%. A breakdown of Clavien-Dindo classification Grade ≥ II post-operative complications was as follows: surgical site infection, one patient (3.8%); ileus, one patient (3.8%); and urinary dysfunction, one patient (3.8%). No surgery-related or in-hospital deaths occurred. The pathological positive resection margin was not observed.

Conclusions: Robotic TME for rectal cancer based on the theory of FUSE can be safely performed, making it a promising surgical procedure. It is suggested that robotic surgeons acquire surgical operation skills with monopolar devices based on the principles of FUSE, which may lead to an increased quality of robotic TME.

Keywords: Fundamental use of surgical energy; Rectal cancer; Robotic surgery; Thermal effect; Total mesorectal excision; Urinary dysfunction.