The definitive version is available at: La versione definitiva è disponibile alla URL: http://link.springer.com/article/10.1007%2Fs00464-013-2962 Since clinical application has begun in the absence of any experimental validation, we assessed its feasibility and efficacy ex vivo in a pilot study. Methods In a dedicated trainer box for transanal procedures, 10 surgeons with no experience in transanal surgery were asked to perform a dissection/suture task using both TAMIS and TEM in randomly allocated order. Surgeons were asked to dissect two identically drawn lesions of ~3 cm in larger diameter. Precision of dissection was assessed using a quantitative photographic method, while the time needed for dissection and suturing was considered a measure of quantitative evaluation. Each participant expressed a subjective opinion regarding difficulty with dissection, difficulty with suturing, vision quality, and conflict between instruments on a scale from 1 to 5.
ResultsNo difference was observed between the two techniques regarding the accuracy of dissection as the margin was interrupted along 4.1 % of the circumference in the TEM group compared with 2.48 % in the SILS group (P = 0.271). Dissection and suturing were significantly quicker in the TEM group [04:30 vs. 06:35 min (P = 0.049) and 14:34 versus 19:18 min (P = 0.003)]. In three cases in the SILS group, completing the suture was not considered possible, and the procedures were terminated by TEM. Subjective evaluation revealed a better appreciation of TEM in all proposed comparisons: dissection (2.6 vs. 3.5, P = 0.004), suturing difficulty (3.1 vs. 4.6, P < 0.001), quality of vision (2.3 vs. 2.8, P = 0.18), and instrument conflicts (3.1 vs. 4.0, P = 0.054). Conclusions In the ex vivo setting, both techniques were comparable for achieving a good dissection, although TAMIS failed to prove effective in suturing the rectal wall. Moreover, TEM was significantly quicker despite the small groups and was better appreciated by the surgeons.