Trans-anal total mesorectal excision - reflections on the introduction of a new procedure

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

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.

Short-term outcomes of pure transvaginal laparoscopic right colectomy: A novel surgery approach based on an Idea, Development, Exploration, Assessment, Long-term framework stage IIa study

BACKGROUND AND OBJECTIVES

The application of pure natural orifice translumenal endoscopic surgery (NOTES) to intra-abdominal visceral resections remains limited due to the complexity of the dissection. This study aimed to assess the safety and feasibility of laparoscopic right colectomy using a purely transvaginal approach.

METHODS

The data of 12 continuous patients with colon neoplasia who underwent transvaginal right colectomy from November 2018 to July 2020 were prospectively collected, and their perioperative events were recorded.

RESULTS

The patients' median age was 70.4 years. Four were diagnosed with colon adenoma and eight with adenocarcinoma. The median operative time was 185 min, with a median blood loss of 25 ml. The median time to gas passing was 32.5 h after surgery. The median postoperative hospital stay was 6 days. One operation was converted to hybrid NOTES due to difficulty with the anastomosis, and one was converted to laparoscopic surgery because of vascular injury. Three cases were grades I, II, and III according to the Clavien-Dindo classification.

CONCLUSION

Pure NOTES right colectomy using the transvaginal approach is feasible and safe with good short-term outcomes. We recommend this novel technique for highly-selected patients with no more than a D2 dissection performed by experienced colorectal surgeons.