Use of Preoperative Hypoalbuminemia as Independent Predictor of Post-Conversion and Revisional Bariatric Surgery Outcomes: MBSAQIP Registry Analysis.

Abstract

Anastomotic conversions and revisions remain crucial in addressing complications or suboptimal outcomes after primary bariatric procedures. Preoperative malnutrition, proxied by hypoalbuminemia, has traditionally been considered a risk factor for postoperative morbidity. This study investigates the validity of this association in revisional and conversion metabolic and bariatric surgery (MBS). A retrospective cohort analysis was performed on 58,327 MBS revisions and anastomotic conversions from the 2020 to 2022 MBSAQIP registry. Approximately all cases studied were performed laparoscopically (98.8%). A preoperative albumin level of 3.5 g/dL was used as a threshold to identify patients with hypoalbuminemia. We used descriptive statistics, univariate and multivariable logistic regression, and 1:1 nearest-neighbor matching in complete-case analyses to explore the relationship between albumin levels and postoperative outcomes. Although univariate analyses illustrate an association between hypoalbuminemia and postoperative morbidity, multivariable regression and 1:1 matched analysis showed hypoalbuminemia is not an independently significant driver of 30-day overall postoperative complications (including leaks), reoperation, or reintervention. However, 1:1 matched analysis demonstrated significantly increased odds of 30-day postoperative superficial surgical site infection (odd ratio 8.138, p = 0.049) and readmission (odd ratio 1.75, p = 0.045) associated with albumin levels lower than 3.5 g/dL. After adjustment for confounding patient factors, hypoalbuminemia alone did not arise as an independent predictive factor for the 30-day major complications, such as leak, reoperation, or reintervention after revisional and anastomotic conversion MBS, although there may be an increase in surgical site infection and readmission rates.