Volume-outcome relationship in adrenal surgery: A review of existing literature.

The relationship between operative volume and perioperative outcomes after several oncologic operations is well documented. Recent studies on adrenalectomy reveal a robust association between higher surgeon volume and improved patient outcomes. Statistical analyses have demonstrated that outcomes are improved when surgeons perform at least six adrenalectomies annually; based on this threshold definition of a 'high-volume' surgeon, more than 80% of adrenalectomies in the United States are performed by 'low-volume' surgeons. When compared to low-volume surgeons, high-volume surgeons on average achieve lower rates of postoperative complications and mortality, as well as a shorter length of hospital stay, and lower cost of hospitalization. There does not appear to be a similar association between hospital adrenalectomy volume and improved patient outcomes; however, there is evidence of benefit for the subset of patients with adrenocortical carcinoma. Despite limitations of existing literature, evidence is sufficient to recommend the referral of patients with adrenal tumors to high-volume surgeons.