Total mesorectal excision for rectal cancer patients: a comparative triple arm study of surgical results in open vs laparoscopic vs robotic-assisted surgery

Abstract

Introduction: The curative intent surgery for rectal cancer is centered around the removal of the tumour-bearing segment with adequately clear margins and en bloc excision of the mesentery containing blood vessels and regional lymphatics. This was traditionally achieved by open surgery which later on was transformed by the introduction of minimally invasive surgery in the form of laparoscopic or the robotic approaches. In this study we aimed to analyse the surgical results in terms of completion of total mesorectal excision (TME), short-term surgical outcomes and hospital stay in open, laparoscopic and robotic-assisted rectal resections. Methods: A retrospective review of a prospectively maintained database of patients operated for carcinoma rectum between January 2013 to August 2018 was included in the study. Data of patients with local invasion (T2-3), with or without node involvement (N0-1), without metastases (M0), who underwent neo-adjuvant chemo/chemo-radiotherapy were included in the study. The neoadjuvant protocol included 50.4Gy-dose EBRT given in 28 fractions over 5.5 weeks, along with systemic 5-fluorouracil-based chemotherapy, followed by surgery 6–8 weeks later. The surgical parameters like completion of total TME, proximal, distal and circumferential resection margins, number of nodes retrieved, and total postoperative hospital stay were analysed in the open, laparoscopic-assisted and robotic-assisted groups. Results: A total of 100 patients were included in the study consisting of 25, 25 and 50 patients each in the open, laparoscopic, and robotic arms, respectively. The conversion rate was 8% (2 of 25) in the laparoscopic-assisted group and 2% (1/50) in the robotic-assisted group. The average postoperative hospital stay was 7.4, 7.36, and 6 days in the open, laparoscopic, and robotic-assisted groups (P = .01). The total number of lymph nodes harvested, circumferential resection margins obtained, and the postoperative hospital stay is summarized in Table 1. When the intactness of TME as reported on the final histopathology was compared, it was seen that there were two patients in the open arm and one patient each in the laparoscopic and robotic arms who had an incomplete TME, but this difference was not statistically significant (P = .45). The proximal and distal margins were negative in all 100 patients. On analysis of the subgroup of patients with low rectal tumours who underwent LAR(n = 28), the mean distal resection margins were 3.14 + 1.5, 4 + 2.8 and 4.7 + 0.8 in the open, laparoscopic, and robotic arms, respectively(P = .21). The CRM obtained in the robotic arm patients was higher than that of the other two groups (P= .005). The mesorectum was reported to be intact in 98% of patients in the robotic arm compared with 96% in laparoscopic and 92% in the open group (P = .38). Conclusion: Robotic rectal resections are associated with better surgical results in the form of improved circumferential resection margins, completeness of TME, and lower conversion rates.