title: Low rates of complications for carotid artery stenting are associated with a high clinician volume of carotid artery stenting and aortic endografting but not with a high volume of percutaneous coronary interventions.
abstract: OBJECTIVE
  Prior studies have demonstrated improved clinical outcomes for surgeons with a high-volume experience with certain open vascular operations. A high-volume experience with carotid artery stenting (CAS) improves clinical outcomes. Moreover, it is not known whether experience with other endovascular procedures, including percutaneous coronary interventions (PCIs), is an adequate substitute for experience with CAS. The goal of this study was to quantify the effect of increasing clinician volume of CAS, endovascular aneurysm repair (EVAR), and thoracic endovascular aortic aneurysm repair (TEVAR), and PCI on the outcomes for CAS.
  
  
  METHODS
  The Nationwide Inpatient Sample was analyzed to identify patients undergoing CAS for the years 2005 to 2009. Clinicians were stratified into tertiles of low-volume, medium-volume, and high-volume groups by annual volume of CAS, EVAR/TEVAR, and PCI. Multiple logistic regression analyses were used to examine the relationship between clinician volume and a composite outcome of the in-hospital stroke and death rate after CAS.
  
  
  RESULTS
  Between 2005 and 2009, 56,374 elective CAS procedures were performed nationwide, with a crude in-hospital stroke and death rate of 3.22%. A median of nine CAS procedures (interquartile range, 3-20) were performed annually per clinician. As expected, stroke and death rates for CAS decreased with increasing volume of CAS performed by a clinician (low-volume vs medium-volume vs high-volume: 4.43% vs 2.89% vs 2.27%; P = .0001). Similar patterns were noted between clinicians' volume of EVAR/TEVAR (low-volume vs medium-volume vs high-volume: 4.58% vs 3.18% vs 2.16%; P = .0023). In contrast, increasing PCI volume was not associated with decreased stroke and death rates after CAS (low-volume vs medium-volume vs high-volume: 2.99% vs 3.18% vs 3.55%; P = .35). After adjusting for patient and hospital characteristics, clinician volume of CAS (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.74-0.94; P = .003) and EVAR/TEVAR (OR, 0.85; 95% CI, 0.75-0.97; P = .020) remained significant predictors of stroke and death after CAS, whereas increasing clinician volume of PCI was associated with significantly increasing likelihood of stroke or death after CAS (OR, 1.025; 95% CI, 1.004-1.047; P = .019).
  
  
  CONCLUSIONS
  The stroke and death rate for CAS to treat carotid stenosis is inversely affected by the number of CAS and EVAR/TEVAR procedures performed by a clinician. In contrast, a high-volume experience with PCI is not associated with improved outcomes after CAS.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex. Electronic address: greg.modrall@utsouthwestern.edu.
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Modrall
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Jayer
authors.initials: J
authors.lastname: Chung
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Melissa L
authors.initials: ML
authors.lastname: Kirkwood
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex; Dallas Veterans Affairs Medical Center, Dallas, Tex.
authors.forename: M Shadman
authors.initials: MS
authors.lastname: Baig
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex; Dallas Veterans Affairs Medical Center, Dallas, Tex.
authors.forename: Shirling X
authors.initials: SX
authors.lastname: Tsai
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Timaran
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: R James
authors.initials: RJ
authors.lastname: Valentine
authors.affiliation: Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, Tex.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rosero
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000706:statistics & numerical data*; D016893:Carotid Stenosis / Q000401:mortality / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D002983:Clinical Competence / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000706:statistics & numerical data*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015607:Stents / Q000009:adverse effects* / Q000706:statistics & numerical data*; D020521:Stroke / Q000453:epidemiology / Q000209:etiology; D014481:United States / Q000453:epidemiology; D058017:Vascular Grafting / Q000706:statistics & numerical data*; D055815:Young Adult