Transanal Total Mesorectal Excision Versus Robotic Total Mesorectal Excision

Transanal Total Mesorectal Excision Versus Robotic Total Mesorectal Excision for Mid and Low Rectal Cancer: A Prospective Randomized Controlled Trial

Background: Laparoscopic total mesorectal excision (TME) for rectal cancer is technically challenging because of the confined space within the pelvis. The robotic surgical system is recently introduced to overcome the limitations of laparoscopy in terms of visualization and maneuverability, but robotic surgery is expensive. Transanal total mesorectal excision (TaTME) is an emerging surgical approach that allows dissection of the most difficult part of the TME plane deep down in the pelvis using a less costly transanal platform. To date, no randomized controlled trial can be found in the literature comparing TaTME and robotic TME.

Objectives: To compare the pathologic outcomes, functional outcomes, and costs between TaTME and robotic TME for mid or low rectal cancer.

Design: Prospective, randomized, controlled, superiority trial.

Subjects: One hundred and eight consecutive patients who are clinically diagnosed with cT1-3, N0-2, M0 rectal cancer located within 12 cm of the anal verge who do not require abdominoperineal resection will be recruited.

Interventions: Patients will be randomly allocated to undergo either TaTME or robotic TME.

Outcome measures: Primary outcome: composite pathologic endpoint (complete TME, clear circumferential and distal resection margins). Secondary outcomes: conversion rate, postoperative recovery, morbidity, health-related quality of life, urosexual function, and costs.

Hypothesis: Results of the present study can provide evidence-based clarification of the efficacy and safety of TaTME for patients with mid and low rectal cancer. The results of this proposed project may have a significant impact on the future treatment strategy for mid and low rectal cancer.

Inclusion Criteria:

• Consecutive patients who are diagnosed with mid or low rectal adenocarcinoma, of which the lowest margin of the tumor is located at or within 12 cm of the anal verge as determined by rigid sigmoidoscopy
• Those with clinically diagnosed cT1-3, N0-2, M0 disease based on preoperative staging with pelvic magnetic resonance imaging, computed tomography, and/or positron emission tomography
• Age of patients greater than or equal to 18 years
• Those with American Society of Anesthesiologists (ASA) grading I-III,
• Informed consent available

Exclusion Criteria:

• Patients with locally advanced cancer not amenable to curative surgery (e.g. involved mesorectal fascia on pelvic magnetic imaging despite neoadjuvant chemoradiotherapy)
• Those with locally advanced T4 cancer requiring en bloc multivisceral resection
• Those with very low rectal tumor requiring abdominoperineal resection
• Those with synchronous colorectal tumors requiring multisegment resection
• Those undergoing emergency surgery
• Those with previous history of abdominal surgery precluding the robotic or laparoscopic approach;
• Those with severe cardiopulmonary disease rendering pneumoperitoneum hazardous
• Those with psychiatric disease
• Those who are pregnant