eP503 - Comparative Analysis of Surgical Approaches for Rectal Cancer: Assessing Short-Term and Pathologic Outcomes in Open, Laparoscopic, and Robot-assisted Procedures

Purpose/Background: In rectal cancer surgery, with the evolution of treatment paradigms through advancement in surgical techniques, there remains an ongoing controversy concerning the advantage of employing minimally invasive techniques over open surgery. This is an observational cohort study that aims to assess the short-term outcomes and pathologic outcomes of patients who underwent rectal cancer resection surgery by open, laparoscopic, and robot-assisted approach at St. Luke’s Medical Center Quezon City and Global City, Metro Manila, Philippines.Methods/Interventions: Patients diagnosed with rectal adenocarcinoma cT1-3NxM0 who underwent surgical resection between July 2018 and June 2023 were identified from medical records. They were categorized based on their scheduled surgical approach: open, laparoscopic, or robot-assisted. The primary outcomes focused on severe post-operative morbidity, as indicated by the Clavien Dindo Classification (CDC) III and IV, and the positive circumferential resection margin (CRM). Secondary short-term outcomes encompassed conversion to open procedure, operative time, 30-day unscheduled re-operations, 30-day post-operative mortality, length of hospital stay, and pathologic outcomes like positive distal resection margin and adequate lymph node yield.Results/Outcomes: The study included a total of 158 patients over five years: 69 (44%) underwent open surgery, 63 (40%) underwent laparoscopic surgery, and 26 (16%) had robot-assisted surgery. Severe post-operative morbidity rates were 8.7%, 11.11%, and 7.69% for open, laparoscopic, and robot-assisted surgeries respectively, with no significant differences (p=0.106). Positive CRM rates were comparable across all groups: 14.49% in open, 7.94% in laparoscopic, and 7.69% in robot-assisted surgeries (p=0.456). Most secondary short-term and pathologic outcomes were consistent across groups. However, laparoscopic and robot-assisted surgeries resulted in a one-day shorter hospital stay compared to the open approach.Conclusion/

Discussion: Robot-assisted rectal cancer surgery offers short-term and pathologic outcomes that are comparable to both open and laparoscopic surgery.Postoperative Short-Term OutcomesTable 3 details the short-term outcomes across the treatment groups. Severe post- operative events, classified as CDC III and IV, were observed to be similar among all groups (8.7% for open surgery, 11.11% for laparoscopic, and 7.69% for robot-assisted, p = 0.11). The 30-day post-operative complications—comprising conditions like ileus, anastomotic leak, sepsis, etc.—as well as 30-day unscheduled reoperations and 30-day postoperative mortality rates, were consistent across all three surgical modalities. Notably, only one mortality was recorded, and this occurred in the open surgery group. In terms of length of hospital stay, patients who underwent minimally invasive procedures (both laparoscopic and robot-assisted) had a median hospital stay that was one day shorter than those who underwent open surgery (6 days for both minimally invasive methods vs. 7 days for open surgery, p = 0.047).