Abstract: Abstract: Objective To investigate the clinical efficacy of robot-assisted radical resection for distal sigmoid colon and rectal cancer. Methods The clinical data of 12 patients underwent robot-assisted radical resection for distal sigmoid colon (n=4) and rectal cancer (n=8) at the Tianjin Medical University Cancer Hospital from August 2016 to December 2018 were retrospectively analyzed. The patients included 5 males and 7 females, ranging in age from 27-72 years with a median age of 59.5 years. Surgical, postoperative recovery and postoperative pathological examination were observed. Follow-up was conducted using outpatient examination and telephone interview to detect postoperative survival, recurrence and tumor metastasis of patients. Results All the 12 patients successfully completed operation with robot-assisted radical resection of distal sigmoid and rectal cancer, without conversion to conventional laparoscopic or open surgery. The operation time and intraoperative blood loss were (282.50±90.72) min and (91.67±41.74) mL respectively without intraoperative complications. Among these patients, there were three with postoperative complications, one case with intestinal obstruction, one case with anastomotic leakage and one with acute ischemic stroke. The patient with acute ischemic stroke was transferred to local hospital for further treatment, and the other two patients with intestinal obstruction and the anastomotic leakage improved after conservative treatment. The duration of postoperative hospital stay was (11.25±4.22) d. The number of harvested lymph nodes after operation was (18.50±7.75) in 12 patients. Surgical margins were negative in 12 patients, and the distance of distal surgical resection margin was (2.21±0.88) cm in 8 patients with rectal cancer. Postoperative tumor pathological staging showed that stage ypT0 was detected in 1 case, pT1 in 2 cases, pT2 in 2 cases, pT3 in 5 cases and pT4a in 2 patients. Postoperative pathological N staging showed that stage pN0 was detected in 7 patients, pN1 in 3 patients and pN2 in 2
patients, respectively. Postoperative tumor pathological type showed that 10 patients were diagnosed with moderate
differentiated adenocarcinoma and 2 patients were diagnosed with low differentiated adenocarcinoma respectively. All the 12
patients were followed-up for 1 to 28 months, with a median follow-up period of 18 months. During the follow-up period, 1
patient died of ischemic stroke and the others had disease-free survival, no recurrence, metastasis or death. Conclusion
Robot-assisted radical resection for distal sigmoid colon and rectal cancer is safe and feasible with satisfactory short-term
results.

Key words: rectal neoplasms, sigmoid neoplasms, robotic surgical procedures, laparoscopes, lymph node excision