Evaluation of laparoscopic-assisted transanal total mesorectal excision(ta-TME) for locally advanced, distal rectal cancer in men with difficult pelvic conditions after neoadjuvant chemoradiation therapy

Abstract

BackgroundTo evaluate the use of laparoscopic-assisted transanal, total mesorectal excision (ta-TME) in men with difficult pelvic anatomy in an attempt to optimize anal sphincteric preservation, determine the completeness of TME, and determine postoperative morbidity and mortality.MethodsTwenty male patients（laparoscopic-assisted transanal total mesorectal excision, A group）with difficult pelvic anatomy (narrow pelvis) who were diagnosed as rectal cancer underwent a Ta-TME surgery from January 2017 to January 2018 at Peking University Cancer Hospital. We matched these 20 patients with 2 other groups of patients who underwent either a laparoscopic transabdominal TME （LA group）or an open transabdominal TME（OP group）according to age, sex, BMI, distance of tumor from the anal verge, and diameter of the tumor. All 3 groups of patients had undergone preoperative neoadjuvant chemoradiation therapy. The efficacy and safety of Ta-TME were evaluated according to operative time, blood loss, postoperative hospital stay, and postoperative complications. Outcomes of Ta-TME were evaluated by comparing the rate of a positive circumferential resection margin, the integrity of the TME, and the rate of sphincter preservation among the 3 groups. We also analyzed whether operative time could be shortened using a laparoscopically assisted Ta-TME through optimizing the surgical procedure.ResultsWhen comparing Ta-TME（TA group）, laparoscopic transabdominal TME(LA group), and open transabdominal TME（OP group, the respective mean blood loss(100mL, 100mL, 100mL, p=0.335),postoperative hospital stay(9 days,9 days,7 days),number of harvested lymph nodes(7, 6, 7,), positive circumferential resection margin rate(0%, 0%, 5%), rate of pathologic complete response(5%,10%,10%,), and integrity of TME showed no statistical differences across groups (p>0.5 for all). In contrast, there were significant differences in operation time(302 min, 253 min, 135 min),rate preservation of the anal sphincter(100%, 30%, 45%,), and the creation of a protective diverting ileostomy(100%, 30%, 45%, p<0.05 for all).ConclusionThe rate of anal sphincter preservation in the Ta-TME group was considerably greater than the other groups, but the safety of the operation did not differ among the 3 groups. The Ta-TME required a diverting ileostomy in all cases, and the total operation time for Ta-TME was greater than that of laparoscopic and open transabdominal TME. We believe that experience and appropriate procedure of the steps of the Ta-TME may lead to a decrease in the operation time.