Physican and Hospital Volume and Outcomes for Endovascular Treatment of AIOD

With innovations in surgical technology, particularly in vascular surgery, aortoiliac occlusive disease (AIOD) is often treated with endovascular methods, including angioplasty and stenting. These techniques are used even in cases of severe AIOD. Advances in stenting techniques to treat more severe lesions while maintaining acceptable clinical outcomes have, according to researchers, “lowered the threshold for treatment and contributed to the rapid diffusion of this technology for the treatment of AIOD.” As the new treatments become more prevalent, specialists treating lesions with an endovascular approach include cardiologists, interventional radiologists, and vascular surgeons. Studies have demonstrated that patients undergoing certain cardiovascular or cancer procedures at high-volume hospitals have a significantly reduced risk of operative death. For many procedures, associations between hospital volume and operative mortality rates are influenced by surgeon volume; patients can further decrease their risk by choosing a surgeon who performs the particular procedure frequently. As study results have established evidence of an association between surgeon volume and outcomes, the proportion of procedures performed by high-volume surgeons has increased. In light of recent evidence that endovascular aortic aneurysm repair at high-volume hospitals resulted in improved survival, shorter length of stay, and reduced cost, researchers recently conducted a study to evaluate the effects of physician volume and specialty and hospital volume on population-level outcomes of endovascular repair in inpatients with AIOD. They reported study results in Archives of Surgery [2011;146(8):966-971]. The study was a retrospective cross-sectional analysis of patients undergoing endovascular repair of AIOD. The researchers utilized data from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample maintained by the Agency for Healthcare Research and Quality. Data from January 2003 through December 2007 were surveyed for International Classification of Diseases, Ninth Revision codes for diagnosis of AIOD and procedures related to endovascular repair to identify patients ≥18 years of age. The primary outcome measures were in-hospital complications and mortality, length of stay, and cost. The researchers defined physician volume as low (<17 procedures per year) or high (≥17 procedures per year). Physicians who performed at least 1 carotid, aortic, or iliac endarterectomy; open aortic repair; above- or below-knee amputation; or aortoiliac-femoral bypass were defined as surgeons for this study. Hospital volume was defined as low (<116 procedures per year) or high (≥116 procedures per year). The researchers identified 818 patients who met inclusion criteria; mean age was 64 years, 54.9% were female, 80.7% were white, 56.6% had a low Charlson Cormorbidity Index score, 35.4% had a nonelective hospital admission, and 66.4% had a diagnosis of iliac occlusive disease. Of the physicians performing the 818 procedures, 59.0% were high-volume surgeons; 65.0% practiced at a high-volume hospital. Unadjusted analyses found significantly higher rates of complications for surgeries performed by low-volume physicians compared with those performed by high-volume physicians (18.7% vs 12.6%; P=.02). There were no significant differences in rates of complications associated with physician specialty (15.5% for surgeons vs 15.9% for nonsurgeons; P=.88) or hospital volume (17.4% for low-volume hospitals vs 13.9% for high-volume hospitals; P=.16). Length of stay was significantly shorter in high-volume hospitals compared with low-volume hospitals (2.8 vs 2.3 days; P=.001); length of stay was significantly shorter when the procedure was performed by high-volume physicians compared with length of stay for patients undergoing procedures performed by low-volume physicians (2.8 vs 3.3 days; P=.03). Compared with nonsurgeons, length of stay was significantly shorter when the procedure was performed by surgeons (2.9 vs 3.2 days; P=.03). Associated costs were significantly lower when the procedure was performed by surgeons compared with procedures performed by nonsurgeons ($11,692 vs $13,656; P=.004). Results from multivariate analyses found significantly lower rates of complications for high-volume physicians compared with low-volume physicians (P=.04), shorter length of stay in high-volume hospitals compared with low-volume hospitals (P=.002), and higher costs with nonsurgeons compared with surgeons (P=.05). In summary, the researchers said, “Overall, volume at the physician and hospital levels appears to be a robust predictor of patient outcomes after endovascular interventions for AIOD. Surgeons performing endovascular procedures for AIOD have a decreased associated hospital cost compared with nonsurgeons.”