Background

Demand for conversion bariatric surgery is increasing. However, contemporary analysis of primary versus conversion Roux-en-Y gastric bypass (RNYGB) is lacking. This study compares clinical outcomes following primary RNYGB, conversion RNYGB from gastric band, and conversion RNYGB from sleeve gastrectomy.

Methods

The 2020 MBSAQIP databank was queried for patients who underwent primary RNYGB, conversion RNYGB from gastric band, or conversion RNYGB from sleeve gastrectomy. Multivariable regression analyses examined the association of surgery type and clinical outcomes while controlling for patient characteristics.

Results

Overall, 46,042 patients were included: primary RNYGB 38,781 (84%), conversion RNYGB from gastric band 2,136 (5%), and conversion RNYGB from sleeve gastrectomy 5,125 (11%). The median age was 45 years, and 7,541 (16.4%) patients were male. Multivariable logistic regression showed that conversion RNYGB from gastric band (odds ratio [OR] 1.793, p=0.032) and conversion RNYGB from sleeve gastrectomy (OR 1.636, p=0.016) were associated with higher rates of anastomotic leak compared to primary RNYGB. Conversion RNYGB from sleeve gastrectomy was associated with higher rates of readmission (OR 1.229, p=0.002) and reintervention (OR 1.366, p=0.006) compared to primary RNYGB. However, conversion RNYGB from gastric band was not significantly associated with differences in readmission (OR 0.807, p=0.061) or reintervention (OR 0.785, p=0.265) compared to primary RNYGB. Reoperation rates did not significantly differ between the three surgeries.

Conclusions

Although leak rates are higher after conversion compared to primary RNYGB, only conversion from sleeve gastrectomy was associated with higher rates of readmission and reintervention. These differences warrant discussion prior to any index bariatric surgery.