Perioperative safety and volume: outcomes relationships in bariatric surgery: a study of 32,000 patients.

Accreditation of Centers of Excellence in bariatric surgery requires a hospital volume of more than 125 procedures/year. There is no evidence-based rationale for this specific threshold. Our objective was to evaluate the contemporary perioperative safety of bariatric surgery and to characterize the relationship between volume and outcomes.We queried the Nationwide Inpatient Sample 2005-2007 for open and laparoscopic bariatric procedures, complications, and death.Thirty-two thousand five hundred and nine bariatric procedures were identified (21% open bypass [Open], 58% laparoscopic bypass [Lap], 21% laparoscopic gastric band [Band]). Inpatient overall mortality was low (total 0.12%, Open 0.3%, Lap 0.09%, Band 0.02%; p < 0.05 for all comparisons). Inpatient complications were more prevalent (total 3.9%, Open 5.9%, Lap 4%, Band 1.6%, p < 0.01 for all comparisons). For all 3 procedures, using a combined end point of mortality and major complications, a volume-outcomes relationship was evident for hospitals. This relationship appeared linear with no clear point that maximally differentiated high- and low-volume centers.Using a nationwide dataset and bariatric procedure-specific data, we have demonstrated that bariatric surgery mortality and complication rates are very low. A definite volume-outcomes relationship exists when hospital-level data are analyzed, but there is no inflection point to justify selecting a specific volume threshold to determine Centers of Excellence. Low-volume centers with extremely low complication rates can be identified and, conversely, there are high-volume centers with elevated rates of complication.