Study protocol for a multicenter prospective controlled and randomized trial of transanal total mesorectal excision versus laparoscopic low anterior resection in rectal cancer.

PURPOSE: Compared with the open approach, laparoscopic total mesorectal excision (TME) achieves faster patient recovery, reduces morbidity rates, and shortens hospital stay. However, in laparoscopic low anterior resection (L-LAR), conversion to open surgery is required in almost 20% of cases. Transanal TME (Ta-TME) combined with laparoscopy, also called hybrid natural orifice transluminal endoscopic surgery (NOTES), is a less invasive procedure that can overcome some of the limitations of laparoscopic rectal surgery. In this study, we aim to determine whether Ta-TME has a lower rate of conversion to open surgery than L-LAR, and thus achieves faster patient recovery without altering the pathological, functional, or oncological results. The main objective is to compare the results for conversion to open surgery between Ta-TME and L-LAR.

METHODS: Multicenter, prospective randomized controlled study of patients diagnosed with rectal adenocarcinoma who will be randomly allocated to Ta-TME or L-LAR groups after the application of inclusion and exclusion criteria. The main endpoint is conversion to open surgery and the secondary endpoints are general morbidity and mortality and hospital stay. Demographic, surgical, and pathological variables will also be studied, along with quality of life and survival. A sample size of 53 patients per group is calculated. With an estimated loss of 10%, the final sample required will be 116 patients.

CONCLUSIONS: Ta-TME achieves a lower conversion rate to open surgery than L-LAR, thus improving patient recovery and reducing overall morbidity.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02550769. Registration no. Ethical and Clinical Research Committee, Parc Taulí University Hospital: ID 2014/064.