Primary Evidence-based Study Of Davinci Robotic-assisted Rectal Cancer Surgery

Objective:1.To compare perioperative safety and long-term outcomes of robot-assisted surgery with laparoscopic surgery for patients with rectal cancer.2.To evaluate the postoperative complications within 30 days of robotic and laparoscopic rectal cancer surgery.3.To evaluate the learning curves of postoperative complications of robotic-assisted laparoscopic surgery for rectal cancer.Methods:1.Patients with middle and low rectal cancer who were treated in the Department of gastrointestinal surgery from October 2016 to August 2020 were prospectively included.Patients were randomized 1:1to either robot-assisted or laparoscopic surgery.The primary end points were the incidence of postoperative complications and 3-year disease-free survival rate.The secondary end points were short-term outcomes,pathological results,urogenital function,rectal function,quality of life and long-term oncological outcomes.2.Randomized controlled trials（until January 2022）that compared robotic and laparoscopic rectal cancer surgery were searched through Pub Med,EMBASE,and the Cochrane Library.Data regarding demographic characteristics and postoperative complications within 30 days et al were extracted.Meta-analysis and Trial Sequential Analysis of the outcomes were performed using Rev Man v5.3 and TSA 0.9.5.10 Beta,GRADE pro3.6 was used to grade the quality of evidence.3.Clinical data on consecutive patients who underwent robotic-assisted total mesorectal excision for rectal cancer by a single surgeon between January 2015 and December 2018 in the Department of gastrointestinal surgery were retrospectively collected.The cumulative sum（CUSUM）and risk-adjusted cumulative sum（RA-CUSUM）were used to visualize the learning curve of operation time and postoperative complications（CD≥grade II）.Comparisons of clinical outcomes at different phases analyzed by RA-CUSUM were performed after propensity score matching.Results:1.A total of 164 patients were randomized,according to the withdrawal criteria,157 patients were eligible for analyses（79 vs.78 respectively）.The basic characteristics were no significant difference between two groups（P>0.05）.The incidence of postoperative complications and 3-year disease-free survival were no significant difference between two groups（17.7%vs.20.5%,P=0.657;88.5%vs.84.4%,P=0.462）.Patient in robotic group lost less blood and achieved more harvested lymph nodes than laparoscopic group（74.0±45.6ml vs.114.9±62.6ml,P=0.000;15.3±6.2 vs.13.1±6.0,P=0.027）than laparoscopic group（74.0±45.6ml vs.114.9±62.6ml,P=0.000）,and the anal preserving rate in robotic group was higher than that in laparoscopic group（83.5%vs.67.9%,P=0.023）,the time to first flatus,time to first liquid intake,time to remove catheter and postoperative hospital stays were no significant difference between two groups（P>0.05）,TME integrity,tumor size,distance to proximal resection margin,distance to distal resection margin,tumor differentiation,number of harvested positive lymph nodes,positive distal resection margins,positive circumferential resection margins and TNM stage were no significant between two groups（P>0.05）.The IPSS of male patients was lower in robotic group than in laparoscopic group at 6 and 12 months after surgery（7.8±2.4 vs.9.8±3.2,P=0.004;7.7±2.8 vs 9.0±2.8,P=0.048）and the IIEF-5 score was higher in robotic group than in laparoscopic group at 6 months after surgery（19.4±3.6 vs.17.3±3.3,P=0.037）;the female IPSS and FSFI score were no significant difference between at different time points（P>0.05）.The results of EORTC QLQ-C30 questionnaire showed that the emotional function was better in robotic group than in laparoscopic group at 6 months after surgery（81.7±6.6 vs.75.5±6.3,P=0.000）,and the scores of economic difficulty in robotic group was higher than laparoscopic group（12.1±6.8 vs.8.2±7.5,P=0.035）,other symptoms and functional scores were no significant at different time points（P>0.05）.The 3-years and 5-years overall survival rate,local recurrence rate and distant metastasis rate were no significant difference between two group（P>0.05）.The total hospital charge and surgery cost were higher in robotic group than in laparoscopic group（63448.7±7596.3 yuan vs.49382.9±7570.8yuan,P=0.000;42161.9±6257.1yuan vs.24161.9±6278.8yuan,P=0.000）.2.Seven randomized controlled trials that included 521 robotic and 530laparoscopic rectal cancer surgery cases were included.Meta-analysis showed that the overall postoperative complications within 30 days,severe postoperative complications,anastomotic leakage,surgical site infection,bleeding,ileus,urinary complications,respiratory complications,conversion to open surgery,unscheduled reoperation,perioperative mortality and pathological outcomes were similar between robotic and laparoscopic rectal surgery（P>0.05）.The Trial Sequential Analysis demonstrated that the overall postoperative complications within 30 days was subject to the risk of type2 errors.3.A total of 389 consecutive patients were included in the analysis.The numbers of patients needed to overcome the learning curves of operation time and postoperative complications of robotic-assisted surgery for rectal cancer were 34 and 36,respectively.The learning process was divided into 2 phases based on RA-CUSUM:the learning phase(1^st-36^th cases)and the mastery phase(37^th-389^th cases).Before matching,the mastery phase had more patients with older age,lower tumor location and neoadjuvant therapy.After matching,the two phases exhibited similar characteristics.The mastery phase had more patients who underwent NOSES than the learning phase.The operation time,intraoperative blood loss,postoperative hospital stay and postoperative complications in the mastery phase were reduced compared to learning phase,with a median follow-up of 35 months,and the long-term oncologic outcomes were not significantly different between the two phases.Conclusion:1.Robotic surgery can reduce intraoperative blood lose,increase the number of harvested lymph nodes and anal preserving rate,improve male urogenital function and emotional function and can achieve similar incidence of postoperative complications and long-term survival compared to laparoscopic surgery.2.Moderate-quality evidence suggested that robotic surgery for rectal cancer was comparable to laparoscopic surgery with respect to postoperative complications within30 days,Future high-quality randomized controlled trials are needed to prove it.3.An experienced laparoscopic surgeon initially implements robotic-assisted total mesorectal excision for rectal cancer,surgical outcomes improved after 36 cases,and the learning curve did not have an obvious impact on long-term oncologic outcomes.