GRAPEVINE, TEX. — Even for experienced bariatric surgeons operating at recognized centers of excellence, the adverse event rate for Roux-en-Y gastric bypass declines by 10% for every additional 10 cases performed annually.
In a large national study, the inverse relationship between surgeon volume and adverse events was continuous. There was no suggestion of any specific volume cut-point that defined a surgeon as an expert, Dr. Mark D. Smith said at the annual meeting of the American Society for Metabolic and Bariatric Surgery.
Dr. Smith, a bariatric surgeon in Portland, Ore., reported on 3,409 patients who underwent an initial Roux-en-Y gastric bypass with 31 surgeons at 10 centers of excellence participating in the National Institute of Diabetes and Digestive and Kidney Diseases-sponsored, prospective Longitudinal Assessment of Bariatric Surgery-1 (LABS-1) study.
Of the 31 surgeons, 15 averaged fewer than 50 of the procedures per year, 9 performed 50-99 annually, and 7 did 100 or more. Both national bariatric surgery centers of excellence programs require that surgeons perform a minimum of 50 cases per year for accreditation.
The primary, composite 30-day adverse event end point comprised death, venous thromboembolism, reintervention, or hospitalization for the full 30 days. It occurred in 4.0% of patients whose surgeons performed at least 50 Roux-en-Y gastric bypasses annually and 9.1% of patients of lesser-volume surgeons. After adjustment for patients' operative risk, the relative risk of adverse events was 2.2-fold greater with surgeons who averaged fewer than 50 cases per year than with those who did more.
After more detailed analysis, it was apparent that the inverse relationship between surgeon volume and adverse outcomes was continuous, and that for every 10 cases performed annually, the risk of adverse events decreased by 10%. The effect of surgeon volume was greater in higher-risk patients, Dr. Smith said.