[Efficacy comparison between robot-assisted and laparoscopic surgery for mid-low rectal cancer: a prospective randomized controlled trial].

Objective: To compare the short- and long-term outcomes of robot-assisted and laparoscopic radical resection for mid-low rectal cancer. Methods: A prospective randomized controlled trial was conducted. A total of 130 patients with mid-low rectal cancer (inclusion criteria: age > 18 or ≤80 years old; pathological diagnosis of rectal adenocarcinoma by colonoscopy; distance from tumor to the anal verge ≤12 cm; no distant metastasis; cT1-3N0-1 or ycT1-3 after neoadjuvant radiotherapy and chemotherapy; suitable for laparoscopic and robotic surgery) at the Department of Colorectal Surgery of the First Affiliated Hospital of Nanchang University from October 2016 to September 2018 were prospectively enrolled. According to computer-generated random number method, patients were randomly divided into the robot group (n=66) and laparoscopy group (n=64), and underwent robot-assisted surgery or laparoscopic surgery respectively. Clinicopathological data of all the patients were collected and analyzed. The demographic parameters, short- and long-term outcomes were compared between two groups. Results: One patient in robot group whose postoperative sample was diagnosed as rectal adenoma by pathology was excluded. There were no statistically significant differences in age, sex, BMI, ASA classification, distance from tumor to the anal verge, serum CEA level, CA199 level between two groups (all P>0.05). Operations were successfully performed in all the patients without conversion to open operation. Robotic surgery was found to be associated with less intraoperative blood loss than laparoscopic surgery [(73.4±49.7) ml vs. (119.1±65.7) ml, t=-4.461, P<0.001], while there were no statistically significant differences in surgical procedures, operation time, time to first flatus, time to first liquid intake, time to removal of catheter or postoperative hospital stay between two groups (all P>0.05). Besides, there was no significant difference in the morbidity of postoperative complication between two groups [10.8% (7/65) vs. 12.5 (8/64), χ(2)=4.342, P=0.720]. The median number of harvested lymph node in the robot group and the laparoscopy group was 15.7±6.2 and 13.8±6.1 (t=1.724, P=0.087). There were no significant differences between two groups in tumor sample length, distance between proximal and distal resection margin, integrity grade of TME specimen, number of positive lymph nodes, postoperative pathological stage and tumor differentiation (all P>0.05). The distal resection margin of samples in two groups was all negative. One case in the robot group was found to have positive circumferential resection margin. The median follow up was 24 (9 to 31) months. In the robot group and the laparoscopy group, the 2-year overall survival rate was 95.4% and 90.6% respectively; the 2-year disease-free survival rate was 90.8% and 85.9% respectively, whose differences were not significant (both P>0.05). Conclusion: Robot-assisted radical resection for mid-low rectal cancer can achieve similar short-term and long-term outcomes of laparoscopic resection, while robot-assisted surgery can decrease blood loss during operation, leading to more precise practice in minimally invasive surgery.目的： 比较达芬奇机器人辅助中低位直肠癌根治术与腹腔镜手术的短期和中长期疗效。 方法： 采用前瞻性随机对照研究方法，前瞻性纳入2016年10月至2018年10月期间在南昌大学第一附属医院结直肠外科拟行根治性手术的130例中低位直肠腺癌患者（入组标准：年龄>18岁，≤80岁；结肠镜活检病理确诊为直肠腺癌；肿瘤距离肛缘≤12 cm；无远处转移；经检查为cT(1~3)N(0~1)或新辅助放化疗后ycT(1~3)；适合接受腹腔镜和机器人手术），根据计算机产生随机数字的方法将纳入患者随机分为机器人手术组（66例）和腹腔镜手术组（64例），分别接受机器人手术和腹腔镜手术，收集所有患者临床及病理资料并进行随访，观察并比较两组患者术后短期和中长期疗效。总生存率和无病生存率采用Kaplan-Meier法并绘制生存曲线，组间差异比较采用log-rank检验。 结果： 机器人手术组1例患者术后病理结果证实为直肠腺瘤后被剔除。两组患者基线资料比较，差异均无统计学意义（均P>0.05）。两组均顺利完成手术，无中转开腹手术患者。两组手术方式、预防性造口、手术时间、首次排气时间、首次进食流质时间、拔除导尿管时间、住院天数比较，差异无统计学意义（均P>0.05）。与腹腔镜手术组相比，机器人手术组术中出血量更少，差异有统计学意义[（73.4±49.7） ml比（119.1±65.7）ml，t=-4.461，P<0.001]；两组术后并发症发生率差异无统计学意义[10.8%（7/65）比12.5%（8/64），χ(2)=4.342，P=0.720]。机器人手术组和腹腔镜手术组淋巴结清扫数目分别为（15.7±6.2）枚和（13.8±6.1）枚，两者比较，差异无统计学意义（t=1.724，P=0.087）。两组患者术后标本肿瘤长径、肿瘤上下切缘距离、全直肠系膜切除完整性分级、阳性淋巴结数目、术后病理分期以及肿瘤分化程度比较，差异均无统计学意义（均P>0.05）；两组术后标本远侧切缘均为阴性，机器人手术组有1例患者环周切缘为阳性。两组患者术后中位随访24（9~31）个月，机器人手术组2年总生存率和2年无病生存率分别为95.4%和90.8%，腹腔镜手术组分别为90.6%和85.9%，两组比较，差异均无统计学意义（均P>0.05）。 结论： 机器人辅助中低位直肠癌根治术疗效与腹腔镜手术相当，但机器人手术能减少术中出血量，更好地实现精准微创。.