Efficacies of transanal total mesorectal excision and laparoscopic total mesorectal excision for rectal cancer

Objective To compare the clinical efficacies of transanal total mesorectal excision(TaTME) and laparoscopic total mesorectal excision (LapTME)for rectal cancer (RC). Methods The case-control matching method and retrospective cohort study were conducted. The clinicopathological data of 100 RC patients who were admitted to the Sixth Affiliated Hospital of Sun Yat-sen University between July 2014 and January 2016 were collected. Of 100 patients, 50 undergoing TaTME and 50 undergoing LapTME were respectively allocated into the TaTME and LapTME groups by case-control matching method. Observation indicators: (1) operation situations: operation time, volume of intraoperative blood loss, cases with intraoperative complications and preventive stoma; (2) postoperative recovery: time for diet intake, time for out-of-bed activity, occurrence of complications within 30 days postoperatively and duration of hospital stay; (3) postoperative pathological examinations: postoperative pathological specimen length, number of lymph node harvest, distance from lower boundary of tumor to distant margin and cases with positive circumferential margin; (4) follow-up. Follow-up using outpatient examination and network tracing was performed to detect local tumor recurrence and distant metastasis up to December 2016. Measurement data with normal distribution were represented as ±s and comparison between groups was analyzed using the paired-samples t test. Measurement data with skewed distribution were represented as M (range). Comparisons of count data were analyzed using the chi-square test. Comparisons of measurement data with skewed distribution and ranked data were done by the nonparametric test. Results (1) Operation situations: operation time, volume of intraoperative blood loss, cases with intraoperative complications and preventive stoma were (259±111)minutes, 100 mL (range, 20-2 000 mL), 2, 28 in the TaTME group and (220±80)minutes, 50 mL (range, 20-1 000 mL), 1, 33 in the LapTME group, respectively, with no statistically significant difference (t=1.90, Z=-0.30, χ2=0.34, 0.01, P>0.05). (2) Postoperative recovery: time for diet intake and time for out-of-bed activity were (1.6±0.5)days, (2.6±0.6)days in the TaTME group and (2.4±0.5)days, (3.5±0.6)days in the LapTME group, respectively, with statistically significant differences (t=8.90, 11.30, P 0.05). Cases with urinary retention within 30 days postoperatively were 3 and 0 in the TaTME and LapTME groups, respectively, with a statistically significant difference (χ2=3.00, P 0.05). (3) Postoperative pathological examinations: postoperative pathological specimen length, number of lymph node harvest, distance from lower boundary of tumor to distant margin and cases with positive circumferential margin were (11±3)cm, 13±5, (1.3±0.7)cm, 0 in the TaTME group and (12±3)cm, 13±5, (1.3±0.7)cm, 1 in the LapTME group, respectively, with no statistically significant difference (t=0.50, 0.20, 0.10, χ2=1.00, P>0.05). (4) Follow-up: 100 patients were followed up for 9-27 months, with an average time of 18 months. During the follow-up, distant metastasis and local tumor recurrence were detected in 2, 3 patients of TaTME group and in 2, 2 patients of LapTME group, respectively, with no statistically significant difference (χ2=0.00, 0.20, P>0.05). Conclusions TaTME for RC is safe and feasible. Compared with LapTME, TaTME not only achieves identical pathological quality without increasing intra- and post-operative complications, but also benefits postoperative recovery of patients. Key words: Rectal neoplasms; Total mesorectal excision; Transanal; Laparoscopy