The endorectal incision level of transanal total mesorectal excision (taTME): An emphasis on the distance from the anterior vs. posterior mesorectal ends to the anal verge - 30/09/22

Doi : 10.1016/j.jviscsurg.2022.08.001

W.M. Ghareeb ^a,^b,^{^{1
Authors are equally contributed.}}, X. Wang ^a,^{^{1
Authors are equally contributed.}}, X. Zhao ^c, S.H. Emile, MD, FACS ^d,^f, S. Shawki ^e,⁎ , P. Chi ^a,⁎
^a Colorectal surgery department, Union Hospital, Fujian Medical University, Fuzhou city, China
^b General and Gastrointestinal surgery department, Suez Canal University, Ismailia, Egypt
^c Laboratory of clinical applied anatomy, Fujian Medical University, Fuzhou city, China
^d Department of Colorectal surgery, Cleveland Clinic Florida, Weston, Florida, USA
^e Department of colon and rectal surgery, Mayo Rochester MN, USA
^f Colorectal Surgery Unit, Mansoura University Hospital, Mansoura, Egypt

^⁎Corresponding author.

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Friday 30 September 2022
Cet article a été publié dans un numéro de la revue, cliquez ici pour y accéder

Résumé

Key points

•	The anterior end of the mesorectum is quite far from the anal verge than the posterior end.
•	In certain individuals with significant distance difference, the endorectal incision level may not meet the mesorectal end during taTME.
•	Aligning the endorectal incision along with the levator hiatus may minimize the potential risk of missing mesorectal tissue posteriorly.

Le texte complet de cet article est disponible en PDF.

Summary

Background

There is no intraluminal guidance to ensure complete inclusion of the mesorectum in transanal total mesorectal excision (taTME). This study aimed to assess the distance difference between the anterior and posterior mesorectal terminal ends and the anal verge as a potential risk for residual mesorectum after resection.

Methods

Forty-four surgical specimens of extra-levator abdominoperineal excision (ELAPE) and 28 mid-sagittal cadaveric specimens were included to this study. The distance between the mesorectum terminal end (T) and the endoluminal landmarks (dentate line (D)/anal verge (A)) was measured and compared between men and women. Furthermore, 66 MRI images from The Cancer Imaging Archive (TCIA) were used to validate the same concept in a non-Asian population.

Results

The mesorectal terminal end was found to be aligned along with the levator hiatus. From the midsagittal view, the ELAPE specimens showed that the distance between T and A anteriorly was significantly longer than the same distance posteriorly (34.74±7.79mm vs 23.74±4.24mm, P<0.001). Similarly, the distance measured in the cadaveric specimens was significantly longer anteriorly than posteriorly (P<0.001). The validation cohort of non-Asian MRI image has confirmed the same (56.68±14.17mm vs. 38.18 ±10.42mm, P<0.001(. There was no significant difference between men and women.

Conclusions

Because of the remarkable distance difference between the anterior and posterior mesorectal terminal ends away from the anal verge, the taTME proctectomy level may not meet the required mesorectal end. Thus, if TME is planned, aligning the proctectomy level around the levator hiatus would be the best place that can ensure complete TME.

Le texte complet de cet article est disponible en PDF.

Keywords : Total mesorectal excision, Transanal Endoscopic Surgery, taTME, TAMIS, Rectal cancer, Surgical anatomy