Additional preparation program for bariatric surgery: Two-year results of a large cohort study.

Background: Multidisciplinary screening of bariatric surgery candidates is recommended, and some centers provide an additional preparation program (APP) to optimize patients preoperatively.

Objective: To compare patients with APP to standard care 2 years after primary bariatric surgery regarding postoperative weight loss and resolution of obesity-related comorbidities.

Methods: A retrospective cohort study was conducted for patients undergoing primary Roux-en-Y gastric bypass and sleeve gastrectomy between September 2017 and March 2019. The first 12 months patients received an APP, after September 2018, the APP was no longer part of the weight loss trajectory. A multivariable linear regression model was built.

Results: Of the 384 patients receiving an APP advice, 50 were lost to follow up. In total, 192 (57%) received the APP and 142 (43%) received standard care. Percentage total weight loss after 2 years was significantly different, 28.8% for the APP group versus 32% for the standard group (p = 0.001). Postoperative weight loss after 2 years was increased in patients who had a gastric bypass, a higher baseline body mass index, and female gender in multivariable analysis. An APP was predictive for decreased postoperative weight. Diabetes mellitus was in remission significantly more often in the preparation group (84.1% of the cases) compared with the standard group (61.9%, p = 0.028).

Conclusion: A weight loss trajectory is at least as effective without additional preparation in terms of 2 years postoperative %TWL for primary gastric bypass and sleeve procedures. For comorbidities, diabetes mellitus was in remission more often in the APP group.