Initial Experience of Transanal Total Mesorectal Excision with Rigid or Flexible Transanal Platforms in Cadavers

Background: Transanal total mesorectal excision (taTME) is expected to provide benefits in the removal of the complete mesorectum for low rectal lesions, and several clinical studies regarding this technique have been reported. However, a transanal platform has not yet been standardized, and diverse transanal endoluminal surgery access devices have been used, based on individual surgeon preferences. In the present study, we performed laparoscopy-assisted taTME in cadavers and compared the characteristics of four different platforms.

Methods: Between January 2013 and April 2015, laparoscopy-assisted taTME was performed on six fresh cadavers. Flexible [SILS™ Port (Covidien), GelPOINT(®) Path Transanal Access Platform (Applied Medical)] and rigid [TEO(®) (Karl Storz Endoskope), TEM (Richard Wolf)] transanal access platforms were used on three cadavers each.

Results: All cadavers were male, with a mean age of 69.2 (range 57-86) years. The mean operation time was 146.3 (range 140-155) min with flexible platforms and 206.7 (range 150-260) min with rigid platforms. The mean specimen length was 23 (range 18-26) cm. Complete or nearly complete mesorectal specimens were obtained in all cases, except for one case using the TEM platform. Flexible platforms (SILS and GelPOINT) provided a short set-up time, relatively atraumatic retraction, and easy application of familiar laparoscopic instruments; a narrow operative field was its limitation. The rigid platforms (TEO and TEM) enabled larger and more stable operative fields and space than did the SILS platform, but they were limited by a narrow view, prolonged set-up time, rigidity, and long channels relative to the short distance from the anus to the rectal closure site.

Conclusion: In this preliminary study, laparoscopy-assisted taTME was a feasible and safe procedure using both rigid and soft platforms, despite some limitations of each platform.