Preoperative body mass index reduction and 30-day outcomes after metabolic and bariatric surgery: an MBSAQIP 2015-2023 analysis.

BACKGROUND

Preoperative weight loss is often recommended before metabolic and bariatric surgery, although its impact on postoperative outcomes, particularly in high body mass index (BMI) patients (e.g., 50.0-59.9, ≥60), is not fully established.

OBJECTIVE

To test the hypothesis that preoperative body mass index reduction (PBR) is associated with improved postoperative outcomes.

SETTING

Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program, 2015-2023.

METHODS

A total of 1,795,127 records were examined, and primary cases were selected while excluding emergencies, revisions, conversions, cases with incomplete data, and preoperative BMI <30 kg/m2. PBR was expressed as a percentage of the highest preoperative BMI. No BMI loss, <10% loss, and ≥10% loss categories were arbitrarily analyzed. Regression analysis was used to analyze outcomes, including prolonged length of stay (>5 days), serious complications, and readmissions.

RESULTS

Among 1,316,050 cases, close to 83% achieved PBR and 6.5% achieved ≥10% PBR. Across all starting BMI, PBR was associated with a lower risk of prolonged length of stay (>5 days). Additionally, for BMI ≥60, there was a significant reduction in serious complications with <10% PBR. Similar trends persisted for >10% PBR for serious complications and readmissions.

CONCLUSIONS

PBR has selective benefits for high-BMI metabolic and bariatric surgery patients. Although complications overall are uncommon, PBR's effect on the risk of these outcomes varies. Focused studies examining well-controlled groups are needed to better understand the potential differences in PBR across the BMI spectrum.