Chi P, Wang X J
Department of Colorectal Surgery, Union Hospital, Fujian Medical University, Fuzhou 350001, China.
Zhonghua Wei Chang Wai Ke Za Zhi. 2023 Jun 25;26(6):548-556. doi: 10.3760/cma.j.cn441530-20230228-00056.
Intersphincteric resection (ISR) is the ultimate sphincter-preserving surgical technique for low rectal cancer. To promote the standardized implementation of ISR, this review discusses the important issues regarding the clinical application of ISR with reference to the latest Chinese expert consensus on ISR. In terms of ISR-related pelvic anatomy of the rectum/anal canal, hiatal ligament is not identical with the anococcygeal ligament. At the level where the rectourethralis muscle continuously extends to the posteroinferior area of the membranous urethra from the rectum, the neurovascular bundle is identified between the posterior edge of rectourethralis muscle and the anterior edge of the longitudinal muscle of the rectum. This knowledge is crucial to detect the anterior dissection plane during ISR at the levator hiatus level. The indication criteria for ISR included: (1) stage I early low rectal cancer; (2) stage II-III low rectal cancer undergoing neoadjuvant treatment, and supra-anal tumors and juxta-anal tumors of stage ycT3NxM0, or intra-anal tumors of stage ycT2NxM0. However, signet ring cell carcinoma, mucinous adenocarcinoma and undifferentiated carcinoma should be contraindicated to ISR. For locally advanced low rectal cancer (especially anteriorly located tumor), neoadjuvant treatment should be carried out in a standardized manner. However, it should be recognized that neoadjuvant chemoradiotherapy was a risk factor for poor anal function after ISR. For surgical approaches for ISR, including transanal, transabdominal, and transanal transabdominal approaches, the choice should be based on oncological safety and functional consequences. While ensuring the negative margin, maximal preservation of rectal walls and anal canal contributs to better postoperative anorectal function. Careful attention must be paid to complications regarding ISR, with special focus on the anastomotic complications. The incidence of low anterior resection syndrome (LARS) was higher than 40%. However, this issue is often neglected by clinicians. Thus, management and rehabilitation strategies for LARS with longer follow-ups were required.
括约肌间切除术（ISR）是低位直肠癌保肛手术的终极技术。为促进ISR的规范化实施，本综述参考最新的中国ISR专家共识，探讨ISR临床应用中的重要问题。在直肠/肛管与ISR相关的盆腔解剖方面，耻骨直肠肌裂隙韧带与肛尾韧带并不相同。在直肠尿道肌从直肠持续延伸至膜性尿道后下区域的层面，神经血管束位于直肠尿道肌后缘与直肠纵肌前缘之间。这一知识对于在提肌裂孔水平进行ISR时确定前方解剖平面至关重要。ISR的适应证标准包括：（1）Ⅰ期早期低位直肠癌；（2）接受新辅助治疗的Ⅱ-Ⅲ期低位直肠癌，ycT3NxM0的肛管上肿瘤和近肛管肿瘤，或ycT2NxM0的肛管内肿瘤。然而，印戒细胞癌、黏液腺癌和未分化癌应禁忌行ISR。对于局部进展期低位直肠癌（尤其是位于前方的肿瘤），应规范进行新辅助治疗。然而，应认识到新辅助放化疗是ISR后肛门功能不良的一个危险因素。对于ISR的手术入路，包括经肛门、经腹和经肛门经腹入路，选择应基于肿瘤学安全性和功能后果。在确保切缘阴性的同时，最大程度保留直肠壁和肛管有助于术后更好的肛肠功能。必须密切关注ISR相关的并发症，尤其要关注吻合口并发症。低位前切除综合征（LARS）的发生率高于40%。然而，这一问题常被临床医生忽视。因此，需要对LARS进行长期随访的管理和康复策略。
