Inter-fascial dissection in laparoscopic colorectal cancer surgery: principles of retraction and exposure and techniques in fascial separation / 中华胃肠外科杂志

Colorectal surgery for malignancies has evolved into an era of careful and precise dissection along mesorectal or mesocolic fascia to achieve the so-called total mesorectal excision or complete mesocolic excision. The wide use of laparoscopic technique prompted more anatomical, histological, and embryological studies. This leads to a deeper and more precise understanding of fascial anatomy concerning colorectal surgery, though controversies exist. The complicated anatomy of multilayer parietal fasciae and dense adhesion between fasciae at specific sites still represent a major hindrance to perform a precise inter-fascial dissection. Colorectal surgeons should be familiar with the onion-like arrangement of the visceral and parietal fasciae. The dedicated assistants should provide three-directional traction and adjust the direction of forces timely in a manner that the resultant forces are always in a direction perpendicular to the fasciae that are to be dissected. The fixation of the mesorectum and the mesocolon to the pelvic and abdominal wall can also be exploited as a natural counter-retraction. To separate loosely attached visceral and parietal fasciae, the application of splitting forces on opposite fasciae or sliding the forceps along the interface will provide quick separation and maintenance of the integrity of the fasciae. In summary, careful attention to the direction and strength of three directional retractions on parietal and visceral fasciae will help stretch and open up the areolar surgical tissue plane, skillful maneuver in separation and dividing of the attachment of two fasciae will ensure a precise inter-fascial dissection and help achieve total mesorectal excision or complete mesocolic excision, reducing the risk of the residual of the mesentery and inadvertent injuries to adjacent tissues and autonomic nerves.

Perirectal fascial anatomy and pelvic autonomic nerve preservation during the transanal total mesorectal excision / 中华胃肠外科杂志

The difficulty of transanal total mesorectal excision (TME) is to find the correct dissection plane of perirectal space. As a complex new surgical procedure, the fascial anatomic landmarks of transanal approach operation are more likely to be ignored. It is often found that dissection plane is false after the secondary injury occurs during the operation, which results in the damage of pelvic autonomic nerves. Meanwhile, the mesorectum is easily damaged if the dissection plane is too close to the rectum. Thus, the safety of oncologic outcomes could be limited by difficulty achieving adequate TME quality. The promotion and development of the theory of perirectal fascial anatomy provides a new thought for researchers to design a precise approach for transanal endoscopic surgery. Transanal total mesorectal excision based on fascial anatomy offers a solution to identify the transanal anatomic landmarks precisely and achieves pelvic autonomic nerve preservation. In this paper, the authors focus on the surgical experience of transanal total mesorectal excision based on the theory of perirectal fascial anatomy, and discuss the feature of perirectal fascial anatomy dissection and technique of pelvic autonomic nerve preservation during transanal approach operation.

Significance of the intact of the fascia propria in protection of pelvic plexus during total mesorectal excision / 中华胃肠外科杂志

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.