Transanal total mesorectal excision with triangle rules: a road map to prevent injuries

Abstract

computed tomography scan of the chest and abdomen, pelvic magnetic resonance imaging scan and endorectal ultrasound identified a lesion at 3 cm from the anal verge, T2/T3a, and a lesion at 15 cm, T2N0, with no evidence of distant metastases. A biopsy was taken and histology revealed an adenocarcinoma. After a multidisciplinary oncology consultation, the patient had neoadjuvant chemoradiation followed by surgery.Circumferential rectal dissection was initiated at the level of the anorectal ring and proceeded posteriorly and cranially in the avascular presacral plane, between the fascia propria of the rectum (enveloping the mesorectum and rectum) and presacral fascia (covering the presacral vein over the sacrum). In the beginning, the dissection needs to be in a downward direction, in order to avoid rectal perforation and respect the presacral plane. This posterior dissection can be more difficult because the posterior slope can be quite steep in some patients, so in these cases the sequence of TaTME does not need to be uniform and can be initiated by the anterior dissection. At the third and fourth sacral vertebra, the Waldeyer fascia is dissected, leading to a superior portion of the retrorectal compartment. The failure to recognize and divide it may result in perforation of the rectum or hemorrhage from the presacral venous plexus. In addition, full mobilization of the rectum is not possible unless the rectosacral fascia is divided. At the level of the sacral promontory, the mesorectum becomes a thick envelope mainly in the dorsolateral position containing perirectal fat, the superior rectal vessels, lymphatic tissue and nerve structures. Usually, the rectal fascia surrounding the mesorectum adheres to the inferior hypogastric plexus (IHP). If careful dissection is not performed, the IHP could be injured and this could lead to postoperative autonomic dysfunction [4].The dissection is extended to the right and to the left of the rectum with the section of the lateral ligament and division of the middle rectal artery, if needed. The lateral ligament Transanal total mesorectal excision (TaTME) is presented as a promising new surgical technique for the approach to the distal rectum, providing the ability to perform a highquality resection, with technical advantages over the laparoscopic approach [1]. However, the new surgical anatomy of the TaTME resection complicates surgical understanding and increases the risks of inadvertent injuries to important anatomic structures [2]. Detailed technical reports and stepwise description are necessary, to facilitate the surgeon's familiarization with this new technique and to reduce the learning curve in a safe manner. This video describes, in both sexes, the TaTME approach highlighting the unique anatomic structures and pitfalls, organized into four virtual triangles (anterior, posterior and two laterals) defining a road map of anatomic landmarks [3].We report the case of a 47-year-old woman complaining of blood loss per rectum. A standard workup which included digital rectal ...

The Pattern of Defects in Mesorectal Specimens: Is There a Difference between Transanal and Laparoscopic Approaches?

“…As a very promising method, TaTME has gained huge interest and several technological modifications since the first human case publication in 2010 (24). Method-driven developments included (a) changing the CO 2 insufflator to one that could deliver a stable flow and provides a stable operative field (25), (b) technical tips of how to fashion anastomosis (26), (c) operative tips (27, 28), and (d) methods of navigation in the pelvis (29, 30). The aim of the ongoing efforts to optimize dissection is an improvement in the oncological quality, which is measured by the quality of the removed mesorectum.…”