INTRODUCTION: The increase in obesity prevalence and longer life expectancy has led to more candidates over 60 pursuing bariatric surgery. While multiple studies have investigated outcomes of sleeve gastrectomy and Roux-en-Y gastric bypass in this age group, the outcomes of duodenal switch (DS) require further investigation. This study assessed the safety and effectiveness of DS in patients over 60 compared to those under 60. METHODS: A retrospective review was conducted for patients from two tertiary referral centers who underwent either biliopancreatic diversion with duodenal switch or single-anastomosis duodeno-ileostomy with sleeve from January 2008 to December 2023. Propensity score matching was used to evaluate the effect of age on outcomes, with 51 patients over 60 in group 1 (G1) compared to 153 patients under 60 in group 2 (G2). RESULTS: At 24 months (follow-up rate of 61% in G1 and 25.5% in G2), G1 had a mean total body weight loss of 41% vs. 35% for G2 (p = 0.437) and mean excess BMI loss of 78% vs. 69% (p = 0.122). G1 had higher complication >
30-day rates (33.3% vs. 13.7%, p = 0.002), reinterventions (19.6% vs. 8.4%, p = 0.030), reoperations (29.4% vs. 13.7%, p = 0.011), and readmissions >
30 days (39% vs. 18.9%, p = 0.003). Most reoperations in G1 were for ventral hernias (46.7%), while in G2, 28.6% were revisions/conversions. Long-term mortality occurred only in G1 (7.8% vs. 0%, p ≤ 0.001), with causes unrelated to bariatric surgery. CONCLUSION: DS procedures offer comparable weight loss for older patients but have higher complication rates, warranting careful consideration and follow-up.