Background

Conversion of sleeve gastrectomy (SG) to Roux-en-Y Gastric Bypass (RYGB) may promote additional weight loss, but some patients benefit much less than others. Objective: To identify predictors of below-average weight loss following SG to RYGB conversion. <

Methods

Chart review was performed of all patients at our institution who underwent SG to RYGB conversion from 11/1/2013 to 11/1/2020. Primary outcomes were below-average percent excess body weight loss (%EBWL) at one and two years. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for numerous pre-revision demographics to evaluate their relationship to the primary outcomes.

Results

Sixty-two patients underwent SG to RYGB conversion with weight loss as a goal. One-year weight data was available for 47 patients. Average one-year %EBWL was 41.5%. Twenty-six patients had below-average %EBWL at one year. Interval to conversion of < 2 years (OR=4.41, 95%CI [1.28,15.17], p=0.019) and pre-conversion BMI > 40 (OR=4.00, 95%CI [1.17,13.73], p=0.028) were statistically significant predictors of below-average one-year %EBWL. Two-year weight data was available for 36 patients. Average two-year %EBWL was 30.8%. Seventeen patients had below-average %EBWL at two years. Evaluated demographics were not statistically significant predictors of below-average two-year %EBWL. There were two 30-day reoperations and zero 30-day mortalities.

Conclusions

In one of the largest single-center studies of weight loss outcomes after SG to RYGB conversion, we found average %EBWL to be 41.5% at one year and 30.8% at two years. Interval to conversion of < 2 years and pre-conversion BMI > 40 were predictors of below-average one-year weight loss.