To evaluate the defecation function of patients with low rectal cancer after laparoscopic-assisted transanal total mesorectal excision (TaTME), and analyze the influencing factors.

The retrospective case-control study was conducted. The clinicopathological data of 55 patients with low rectal cancer who underwent laparoscopic-assisted TaTME in the First Hospital of Jilin University from May 2017 to December 2018 were collected. There were 39 males and 16 females, aged (60±11)years, with a range from 24 to 80 years. Among the 55 patients, 21 were in TNM stage Ⅰ, 14 were in TNM stage Ⅱ, and 20 were in TNM stage Ⅲ; 24 were in pathological stage T1-2 and 31 were in pathological stage T3. Observation indicators: (1) surgical and postoperative conditions; (2) follow-up; (3) analysis of influencing factors for postoperative defecation function. Follow-up was performed using questionnaires by telephone interview to detect the complications at 3 and 6 months after surgery up to June 2019. The measurement data with normal distribution were expressed as Mean±SD, and comparison between groups was done using the t test. Count data were expressed as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Univariate and multivariate analyses were performed using logistic regression models.

(1) Surgical and postoperative conditions: 55 patients successfully underwent laparoscopic-assisted TaTME without conversion to open surgery. The operation time, volume of intraoperative blood loss, diameter of postoperative pathological specimen, time to urinary catheter removal, distance between the anastomostic stoma and anal verge, and tumor diameter were (246±62)minutes, (69±27)mL, (3.5±0.7) cm, (2.1±0.9)days, (2.4±0.5)cm, and (3.9±1.6)cm, respectively. (2) Follow-up: 55 patients were followed up at 3 months and 6 months after surgery, and the low anterior resection syndrome questionnaires were completed. Among the 55 patients, 35 had low anterior resection syndrome at 3 months after surgery, and 24 had low anterior resection syndrome at 6 months after surgery, showing a significant difference (χ²=4.42, P<0.05). There was no new onset low anterior resection syndrome in 55 patients after 3 months. (3) Analysis of influencing factors for defecation function: univariate analysis showed that the distance between the anastomotic stoma and anal verge and tumor diameter were influencing factors affecting defecation function of patients at 3 months after surgery (χ²=19.075, 8.185, P<0.05). The distance between the anastomotic stoma and anal verge was a influencing factor affecting the defecation function of patients at 6 months after surgery (χ²=9.183, P<0.05). Multivariate analysis showed that the distance between the anastomotic stoma and anal verge < 2 cm, and tumor diameter >5 cm were independent risk factors affecting the defecation function of patients at 3 months after surgery (odds ratio=1.135, 6.057, 95% confidence interval: 1.089-1.323, 1.206-30.435, P<0.05). The distance between the anastomotic stoma and anal verge <2 cm was an independent risk factor affecting the defecation function of patients at 6 months after surgery (odds ratio=2.724, 95% confidence interval: 1.982-3.066, P<0.05).

The incidence of low anterior resection syndrome after laparoscopic-assisted TaTME for low rectal cancer is high. Distance between the anastomotic storna and anal verge and tumor diameter are independent risk factors for the postoperative defecation founction.

Rectal neoplasms; Rectal cancer; Transanal total mesorectal excision; Low anterior resection syndrome; Laparocopy