Long-Term Weight Loss and Comorbidity Resolution of Laparoscopic Sleeve Gastrectomy and Laparoscopic Roux-en-Y Gastric Bypass and the Impact of Preoperative Weight Loss on Overall Outcome

Background: The impact of preoperative weight loss on long-term weight loss outcomes and comorbidity resolution in both laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) are poorly reported. Understanding this relationship is necessary to guide surgeons toward appropriate procedure and patient selection. The present study investigates long-term weight loss outcomes and comorbidity resolution following LSG and LRYGB and investigates the effect of preoperative variables on long-term outcomes. Methods: All patients who underwent LSG and LRYGB (2008-2022) in a tertiary referral centre were followed up prospectively. From 2010, a 12-week intensive preoperative information course (IPIC) became standard practice to optimize preoperative weight loss. Excess weight loss outcomes (EWL≥50% and ≥70%) were compared between LSG and LRYGB using multivariate logistic regression and the effect of preoperative weight loss on weight loss and comorbidity resolution, improvement, and exacerbation were reported. Results: A total of 319 patients (median age: 49 y; M:F, 75:244) were included (158 LSG: 161 LRYGB). During follow-up, 260 (81.5%) and 163 patients (51.1%) achieved EWL≥50% and ≥70%, respectively. Those with sustained EWL≥50% and EWL≥70% at the end of follow-up were more likely to have underwent a LRYGB versus a LSG (59.6% vs. 40.4%, P =0.002; 61.7% vs. 38.3%, P <0.001). IPIC and higher preoperative weight loss (HR: 2.59 to 3.72, P <0.001) increased rates of EWL≥50% and EWL70% for both procedures. Improvement or resolution of type-2 diabetes were significant (72.7%), but up to 27.3% of patients developed or suffered an exacerbation of a psychiatric illness. Conclusions: Excess weight loss outcomes are similar for LSG and LRYGB but LRYGB results in higher rates of sustained excess weight loss during long-term follow-up. Preoperative weight loss improves long-term weight loss. Comorbidity resolution is significant but rates of psychiatric illness exacerbation are high following metabolic and bariatric surgery.