Journal of Obesity & Eating Disorders

Description

Over recent decades, obesity rates have surged globally, particularly in industrialized nations. Bariatric surgeries, notably sleeve gastrectomy and Roux-en-Y Gastric Bypass (RYGB), have emerged as effective interventions for sustained weight loss in obese patients. While RYGB generally yields significant weight loss, about 25% of patients experience inadequate results, termed surgical nonresponse. Moreover, many patients harbor unrealistic weight loss expectations despite preoperative counseling, with up to 60% overestimating postoperative outcomes. Personalized predictive models offer promise in setting realistic expectations and aiding clinical management. The Seyssel model, leveraging preoperative parameters like weight, age, height, and gender, has shown promise in predicting postoperative BMI changes. This retrospective study aimed to assess the Seyssel model's efficacy in promptly identifying surgical nonresponse during a 2-year follow-up post- RYGB.

Weight changes

Analyzing weight and BMI changes, deviations from predicted outcomes were scrutinized, defining surgical nonresponse as actual weight exceeding predicted weight by +1 standard deviation. Additionally, the impact of patients' desired weight on observed outcomes was evaluated. The study encompassed primary RYGB patients between 2016 and 2019, excluding those with incomplete follow-up, pregnancy, or revisional surgery. With preoperative preparation by a multidisciplinary team, laparoscopic RYGB was uniformly performed. Findings aimed to validate the Seyssel model's utility in predicting postoperative outcomes and its role in early detection of surgical nonresponse. Post-bariatric surgery weight loss is crucial for patient and physician concerns, with early outcomes often indicating longterm success. Various personalized models have emerged to predict postoperative weight loss, but detecting nonresponse in the early postoperative period remains challenging due to the absence of reference values. Unlike other models, the Seyssel model offers graphical weight predictions and incorporates Standard Deviation (SD) values, aiding in early nonresponse detection. Our study revealed that a significant proportion of patients exhibiting surgical nonresponse at 24 months already showed deviation from predicted weight at 3 and 12 months, using a threshold of +1 SD. This underscores the Seyssel model's potential for early detection. While no clear definition of surgical nonresponse exists, our chosen threshold aligns with previous studies defining nonresponse as <25% total weight loss. Physicians should closely monitor patients showing early deviation from predicted weight, providing interventions to bolster weight loss and avert nonresponse. Conversely, patients achieving adequate weight loss within the first postoperative year are likely to maintain success at 24 months, as indicated by the model's high negative predictive value.

Psychological factors

The Seyssel model's graphical representation facilitates differentiation between patient groups, aiding in effective clinical management and patient motivation. Despite comprehensive preoperative counseling, many patients hold unrealistic weight loss expectations, with overestimation observed in a significant portion. However, patients aiming for lower weights than predicted by the model achieved higher weight loss, suggesting the potential impact of managing expectations on outcomes. Nevertheless, our study has limitations, including the lack of assessment of socioeconomic and psychological factors, potential bias due to loss to follow-up, and a small, homogeneous sample size. Further research addressing these limitations could enhance our understanding of post-bariatric surgery outcomes and refine predictive models for improved clinical utility.