Background and Aims: Total mesorectal excision (TME) is a standard technique for treatment of rectal cancer. Compared with open TME, laparoscopic-assisted TME (LaTME) has not only the advantage of minimal invasiveness, but also similar oncological outcomes. However, in obese, narrow-pelvis or male low rectal cancer patients, the pelvic operation of LaTME is still difficult, with increased risk of positive circumferential resection margin (CRM). The advent of laparoscopic-assisted transanal TME (TaTME) provides an innovative and minimally invasive option for low rectal cancer resection and provides new solutions for surgeons. This study was conducted to compare and analyze the clinical efficacy of laparoscopic-assisted TaTME and LaTME in treatment of low rectal cancer. 
Methods: The clinical data of 30 patients with low rectal cancer (the distance between inferior margin of tumor and anal verge ≤5 cm) treated in the Department of Gastrointestinal Surgery, Guangdong Provincial Hospital of Traditional Chinese Medicine from July 2018 to January 2019 were retrospectively analyzed. Of the patients, 12 cases underwent laparoscopic assisted TaTME (TaTME group), and 18 cases underwent LaTME (LaTME group). The main clinical variables were compared between the two groups of patients.
Results: There were no significant differences between the two groups of patients in terms of general data such as age, sex, BMI, ASA grade, oncological stage, distance from the inferior margin of the tumor to the anus, and tumor diameter (all P>0.05). No open conversion required and no early death occurred in both groups. The operative time of TaTME group was significantly shorter and the intraoperative blood loss was significantly less than those of LaTME group (168.5 min vs. 239.33 min, P=0.007; 66.50 mL vs. 160.00 mL, P=0.002), and no significant differences were noted with regard to preventive ileostomy, anus preservation rate, CRM-positive rate and total lymph node dissection (all P>0.05). The length of hospital stay of TaTME group was significantly shortened and the hospitalization cost was significantly reduced in TaTME group compared with LaTME group (6.33 d vs. 10.83 d, P<0.001; 58 963 yuan vs. 81 341 yuan, P<0.001), and the time to postoperative anal gas passage and time to whole liquid diet in TaTME group were all shortened compared with LaTME group, but the differences did not reach statistical significance (both P>0.05). The incidence rates of postoperative complications showed no significant difference between the two groups (P>0.05).
Conclusion: Laparoscopic-assisted TaTME has a similar short-term efficacy as laTME in treatment of low rectal cancer, and also offers advantages in certain respects. It is safe and feasible, and it is worthy of further exploration and application.