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.
经括约肌间切除术（ISR）是低位直肠癌极限保肛手术。为促进ISR手术的规范实施，本文追溯ISR的发展历程，并参照最新发布的《低位直肠癌经括约肌间切除术中国专家共识（2023版）》讨论制定过程中的投票情况，对ISR在临床应用中的诸多重要议题进行论述。直肠肛门的ISR相关局部解剖学问题方面，肛尾韧带和裂孔韧带并非同义词；直肠纵肌发出直肠尿道肌的移行处，可观察到神经血管束（NVB）的分支分布。ISR适应证及禁忌证方面，Ⅰ期不适合局部切除的低位直肠早癌和Ⅱ~Ⅲ期低位直肠癌新辅助治疗后，肛提肌裂孔以上的肿瘤降期为ycT3NxM0以下、肛提肌裂孔以下降期为ycT2NxM0以下者，可行ISR。低位直肠印戒细胞癌、黏液腺癌和未分化癌为ISR手术禁忌。对于局部进展期低位直肠癌（特别是前壁肿瘤），应规范地行新辅助治疗，同时亦应认识到新辅助放化疗是ISR术后肛门功能不良的危险因素。经肛、经腹以及经腹经肛混合3种ISR入路方式的选择应基于根治性和功能性，在保证切缘阴性的前提下，尽量多保留远端健康肠管。应重视围手术期并发症，特别是吻合口并发症的诊治。超过40%的ISR术后患者遭受不同程度的低位前切除综合征，但常为临床医师所忽视，应重视其术后随访和康复锻炼。.