Transanterior obturator nerve gateway: a novel approach to achieving intracorporeal distal rectal transection for ultralow rectal cancer

Abstract
Background Intracorporeal rectal transection at the anorectal junction for ultralow rectal cancer is technically difficult due to pelvic width and limited roticulation, which might require a transanal transection or an oblique transection with multiple firings. These procedures were reported to be associated with the increased risk of morbidity. To address these problems, we presented a novel technique Transanterior Obturator Nerve Gateway (TANG) to transect rectum for ultralow rectal cancer and evaluated its safety and feasibility in this study. Methods A total of 210 consecutive patients who underwent laparoscopic coloanal anastomosis with or without partial intersphincteric resection (CAA/pISR) for rectal cancers between January 2017 and January 2020 were included. Eighty of these patients were analyzed using propensity score matching (PSM). The perioperative characteristics, TANG-related variables, and genitourinary and anal function outcomes were analyzed. Results Among these enrolled patients, 170 patients underwent traditional transection, and 40 underwent TANG transection; the patients were matched to include 40 patients in each group by PSM. After PSM, there were no significant differences in the operating time (p = 0.351) or bleeding volume (p = 0.474) between the two groups. However, the TANG group had fewer cases of conversion to transanal transection (0 vs. 13, p < 0.001). Moreover, the patients in TANG group had a more desirable transection with longer distal resection margin (1.7 vs. 1.1 cm, p < 0.001), shorter stapling line (6.6 vs. 10.3 cm, p < 0.001) and fewer stapler firings (p < 0.001). The overall postoperative complication rates and genitourinary and anal function outcomes were not significantly different between the two groups. Conclusions The TANG approach appears to be a safe, feasible and effective approach for intracorporeal ultralow rectal transection with more distal resection, more vertical transection and fewer stapler firings.