[Significance of the intact of the fascia propria in protection of pelvic plexus during total mesorectal excision].

Total mesorectal excision (TME) is the gold standard of surgical treatment for mid and low rectal cancer. It aims to improve the oncological outcomes as well as preserve anal sphincter, sexual and urinary function. Compared with sympathetic nerve injury alone, pelvic plexus and neurovascular bundle (NVB) injury has significant effect on postoperative sexual dysfunction, especially erectile function. Since the lateral surgical plane of TME is narrow and densely packed, dissecting outside the plane causes pelvic plexus injury, while dissecting inside it results in residual mesorectum. In this commentary, we review the research progress of lateral fascial anatomy of TME, and describe the anatomical characteristics of rectosacral fascia based on our previous research results. The prehypogastric fascia acts as a "fascia barrier" when dissecting the lateral space constantly from posterior to anterior. In addition, the pelvic plexus fuses with the prehypogastric fascia which is considered as the outer side layer of rectosacral fascia laterally. Thus, the rectosacral fascia should be dissected at the level of S4 vertebral body posterior to the rectum in an arc shape and then enter the superior-levator space. Before dissecting the lateral spaces, the anterior space of the rectum should be dissected first. After an "U" shape cutting of the Denonvilliers' fascia, the lateral space should be dissected from anterior to posterior. Finally, the lateral attachment of rectosacral fascia is transected to ensure the integrity of the mesorectum without damaging the pelvic plexus.