Short- and Long-Term Outcomes of Minimally Invasive Total Mesorectal Excision in Obese versus Non-Obese Patients With Rectal Cancer: A Propensity Score–Matched Study

Background: Obesity adds technical complexity to colorectal surgery and has been linked to higher rates of perioperative complications and poorer long-term outcomes. Its prevalence is increasing among patients undergoing minimally invasive total mesorectal excision for rectal cancer; however, its impact on perioperative and oncologic outcomes remains controversial. Therefore, the aim of this study was to compare short- and long-term outcomes between obese (BMI ≥27 kg/m²) and non-obese patients undergoing minimally invasive total mesorectal excision. Methods: Retrospective review of rectal cancer patients undergoing laparoscopic, robotic, or transanal TME between January 2015 and December 2022. Propensity score matching (1:1) was performed on baseline characteristics. Primary outcomes included perioperative parameters, postoperative complications, and long-term oncologic outcomes. Results: After matching, 142 patients were included in each group. Obesity was associated with higher conversion rates to open surgery (2.8% vs. 0%, p=0.044) and increased overall complications (40.1% vs. 28.9%, p=0.046), driven mainly by surgical wound infections (9.2% vs. 1.4%, p=0.004). No differences were observed in major complications, anastomotic leakage, hospital stay, margin status, or five-year overall (88% vs. 89.4%, p = 0.409) and disease-free survival (62.7% vs. 72.5%, p = 0.653). Conclusion: Obesity increased conversion and minor complication rates but did not adversely affect short-term outcomes or long-term oncologic outcomes after minimally invasive TME procedures. Tailored perioperative strategies may mitigate obesity-associated risks. Trial registration: Not applicable.