Conversion of gastric sleeve to Roux-en-Y gastric bypass: overall outcomes and predictors of below-average weight loss.

Abstract

Conversion of sleeve gastrectomy (SG) to Roux-en-Y gastric bypass (RYGB) has been utilized to promote further weight loss, but results are variable in available literature. To evaluate outcomes of SG to RYGB conversion for weight loss and to identify predictors of below-average weight loss. University-affiliated hospital, United States. Chart review was performed of our patients who underwent SG to RYGB conversion from November 1, 2013, to November 1, 2020. Primary outcomes were below-average percent excess weight loss (%EWL) at 1 and 2 years. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for preconversion demographics to evaluate their relationship to the primary outcome. Sixty-two patients underwent conversion from SG to RYGB with weight loss as a goal. One-year data was available for 47 patients. The average %EWL at 1 year was 41.5%. Twenty-six patients had below-average %EWL at 1 year. Interval to conversion <2 years (OR = 4.41, 95% CI [1.28,15.17], P = .019) and preconversion body mass index (BMI) >40 (OR = 4.00, 95% CI [1.17,13.73], P = .028) were statistically significant predictors of below-average 1-year %EWL. Two-year data was available for 36 patients. The average %EWL at 2 years was 30.8%. Seventeen patients had below-average %EWL at 2 years. Evaluated demographics were not statistically significant predictors of below-average 2-year %EWL. Following SG to RYGB conversion, %EWL outcomes are lower at 1 year (41.5%) and 2 years (30.8%) than reported values for primary RYGB. Interval to conversion <2 years and preconversion BMI >40 are predictors of below-average 1-year weight loss after conversion.