经肛全直肠系膜切除术尿道损伤的发生机制及预防措施

Mechanism and prevention of urethral injury during transanal total mesorectal excision

近年来,经肛全直肠系膜切除术(taTME)已成为结直肠外科关注的焦点之一。然而,其仍面临一些争议性的问题尚未解决,在并发症方面,尿道损伤概率升高就是典型。本文分别从泌尿外科和直肠外科的角度,阐述目前关于直肠尿道之间相关解剖的研究进展。从尿道解剖的角度来看,涉及taTME手术发生尿道损伤的主要结构为直肠尿道肌;而从直肠解剖的角度来看,这个所谓的直肠尿道肌就是直肠纵肌的一部分。综合现有的研究结果,笔者提出关键性的解剖结构——Hiatal韧带的全新观点,即Hiatal韧带其实是环绕直肠一周的直肠纵肌的分支,在前、后正中部位最为肥厚,并向1点和11点方向逐渐变薄,其在前方的部分即被泌尿外科命名为直肠尿道肌。在此基础上,进行taTME手术时,建议按照"先两侧、后正中"的分离原则,即先离断两侧薄弱的Hiatal韧带,进入熟悉的间隙,然后离断正中肥厚的部分。必要时可通过直肠指诊和荧光尿管等导航方法,帮助确认尿道和前列腺位置,找到正确平面。本文希望通过介绍taTME手术的相关解剖以及避免尿道损伤的各种方法,以推动taTME手术进一步的开展和普及。

In recent years, transanal total mesorectal excision (taTME) has become one of the focuses of colorectal surgery, but it still faces some controversial problems that have not been solved, such as urethral injury as a typical complication. This paper, from the perspective of urological and rectal surgery respectively, elucidates the current research progress on the anatomy between the rectum and urethra. From the perspective of urethral anatomy, the main structure involving urethral injury in taTME surgery is the rectourethral muscle, which actually is part of the longitudinal muscle of the rectum from the perspective of rectal anatomy. Summarizing existing research results, the authors propose a new perspective about the key anatomical structure of hiatal ligament. As a matter of fact, hiatal ligament is the branch of longitudinal muscle of the rectum which circles the rectum, and the thickest part is at the center of the front and back respectively, then becomes thinner gradually to the 1 o′clock and 11 o′clock position. The front part of the hiatal ligament is just named as rectourethral muscle for urology surgery. On this basis, when taTME surgery is performed, it is recommended to follow the principle of "lateral first, center later", that is, the thin lateral parts of hiatal ligaments is separated first, then the thick central parts after entering the familiar space. If necessary, the position of urethra and prostate can be confirmed through digital rectal examination, fluorescence catheter or other navigating methods. This paper aims to promote further development and popularization of taTME by introducing relevant anatomy of taTME surgery and various methods to avoid urethral injury.