Customized Denonvilliers' Fascia Excision: An Advanced Total Mesorectal Excision Technique for Anteriorly Located Rectal Cancer

Abstract

Background: The role of Denonvilliers' fascia in achieving a negative circumferential resection margin during anterior total mesorectal excision has been controversial. Opinions on whether to dissect in the anterior or posterior surgical plane varies among researchers.

Impact of innovation: We performed total mesorectal excision with selective en bloc resection of Denonvilliers' fascia based on preoperative MRI staging, preoperative clinical tumor stage, and tumor level in selected patients with anterior rectal tumors adherent to Denonvilliers' fascia.

Technology materials and methods: Between March and August 2021, 5 patients who underwent robotic (n = 4) and laparoscopic (n = 1) total mesorectal excision for anteriorly located low rectal adenocarcinomas after neoadjuvant chemoradiotherapy were enrolled in this study. Transabdominal total mesorectal excision dissection is performed by changing to a plane anterior to Denonvilliers' fascia, with partial or total excision tailored to the tumor level and depth of invasion as a further step in circumferential resection margin clearing. Customized excision of Denonvilliers' fascia was performed by dissecting through the extramesorectal plane. This anterior plane permits resection of Denonvilliers' fascia, exposing the prostate and seminal vesicles.

Preliminary results: Two tumors were located at the seminal vesicle level and 3 were found at the prostate level. The mean distance from the anal verge to the distal margin of the tumor was 4.8 ± 0.9 cm. Denonvilliers' fascia was preserved in 1 patient and partially excised in 4. Customized Denonvilliers' fascia excision was performed in 3 robotic ultralow anterior resections with coloanal anastomosis, 1 laparoscopic ultralow anterior resection with coloanal anastomosis, and 1 robot-assisted abdominoperineal resection. The circumferential resection margins in all patients were negative.

Conclusions and future directions: Anterior dissection in front of Denonvilliers' fascia can be selectively performed during total mesorectal excision based on preoperative planning, tumor location, and clinical tumor stage. Preoperative MRI and magnified operative views in minimally invasive platforms provide access to more precise surgical planes for clear circumferential resection, achieving optimal functional outcomes and oncological safety.