title: Carotid stenting: is there an operator effect? A pooled analysis from the carotid stenting trialists' collaboration.
abstract: OBJECTIVE
  Randomized clinical trials show higher 30-day risk of stroke or death after carotid artery stenting compared with surgery. We examined whether operator experience is associated with 30-day risk of stroke or death in the Carotid Stenting Trialists' Collaboration database.
  
  
  METHODS
  The Carotid Stenting Trialists' Collaboration is a pooled individual patient database including all patients recruited in 3 randomized trials of stenting versus endarterectomy for symptomatic carotid stenosis (Endarterectomy Versus Angioplasty in patients with Symptomatic Severe Carotid Stenosis trial, Stent-Protected Angioplasty versus Carotid Endarterectomy trial, and International Carotid Stenting Study). Lifetime carotid artery stenting experience, lifetime experience in stenting procedures excluding the carotid, and annual number of procedures performed within the trial (in-trial volume), divided into tertiles, were used to measure operator experience. The outcome event was the occurrence of any stroke or death within 30 days of the procedure. The analysis was done per protocol.
  
  
  RESULTS
  Among 1546 patients who underwent carotid artery stenting, 120 (7.8%) had a stroke or death within 30 days of the procedure. The 30-day risk of stroke or death did not differ according to operator lifetime carotid artery stenting experience (P=0.8) or operator lifetime stenting experience excluding the carotid (P=0.7). In contrast, the 30-day risk of stroke or death was significantly higher in patients treated by operators with low (mean ≤3.2 procedures/y; risk 10.1%; adjusted risk ratio=2.30 [1.36-3.87]) and intermediate annual in-trial volumes (3.2-5.6 procedures/y; 8.4%; adjusted risk ratio=1.93 [1.14-3.27]) compared with patients treated by high annual in-trial volume operators (>5.6 procedures/y; 5.1%).
  
  
  CONCLUSIONS
  Carotid stenting should only be performed by operators with annual procedure volume ≥6 cases per year.
authors.affiliation: From the Department of Neurology, Hôpital Sainte-Anne, Université Paris Descartes, INSERM UMR894, Paris, France (D.C., J.-L.M.); Department of Neurology and Julius Centre for Health Sciences and Patient Care (A.A.) and Department of Radiology (W.P.M.), University Medical Centre Utrecht, Utrecht, The Netherlands; Department of Vascular Surgery, University Hospital Henri Mondor, Creteil, France (J.-P.B.); Department of Neurology and Stroke Unit, University Hospital Basel, Basel, Switzerland (L.H.B.); Department of Brain Repair and Rehabilitation, Institute of Neurology, University College London, London, United Kingdom (L.H.B., M.M.B.); Medical Statistics Unit, Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom (J.D.); Department of Vascular Surgery, Medical University, Innsbruck, Austria (G.F.); Department of Neuroradiology, Schleswig-Holstein University Hospital, Kiel, Germany (O.J.); Department of Neurology, University Hospital Heidelberg, Heidelberg, Germany (P.A.R.); and Clinical Research Unit, Hôpital Européen Georges Pompidou, Université René Descartes, Paris, France (G.C.).
authors.forename: David
authors.initials: D
authors.lastname: Calvet
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Mas
authors.forename: Ale
authors.initials: A
authors.lastname: Algra
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Becquemin
authors.forename: Leo H
authors.initials: LH
authors.lastname: Bonati
authors.forename: Joanna
authors.initials: J
authors.lastname: Dobson
authors.forename: Gustav
authors.initials: G
authors.lastname: Fraedrich
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
authors.forename: Willem P
authors.initials: WP
authors.lastname: Mali
authors.forename: Peter A
authors.initials: PA
authors.lastname: Ringleb
authors.forename: Gilles
authors.initials: G
authors.lastname: Chatellier
authors.forename: Martin M
authors.initials: MM
authors.lastname: Brown
authors.forename: D
authors.initials: D
authors.lastname: Calvet
authors.forename: J L
authors.initials: JL
authors.lastname: Mas
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: J P
authors.initials: JP
authors.lastname: Becquemin
authors.forename: L H
authors.initials: LH
authors.lastname: Bonati
authors.forename: J
authors.initials: J
authors.lastname: Dobson
authors.forename: G
authors.initials: G
authors.lastname: Fraedrich
authors.forename: O
authors.initials: O
authors.lastname: Jansen
authors.forename: W P
authors.initials: WP
authors.lastname: Mali
authors.forename: P A
authors.initials: PA
authors.lastname: Ringleb
authors.forename: G
authors.initials: G
authors.lastname: Chatellier
authors.forename: M M
authors.initials: MM
authors.lastname: Brown
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: J P
authors.initials: JP
authors.lastname: Becquemin
authors.forename: G
authors.initials: G
authors.lastname: Chatellier
authors.forename: J L
authors.initials: JL
authors.lastname: Mas
authors.forename: G
authors.initials: G
authors.lastname: Fraedrich
authors.forename: P A
authors.initials: PA
authors.lastname: Ringleb
authors.forename: O
authors.initials: O
authors.lastname: Jansen
authors.forename: M M
authors.initials: MM
authors.lastname: Brown
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty; D016893:Carotid Stenosis / Q000150:complications / Q000401:mortality / Q000601:surgery*; D002985:Clinical Protocols; D016208:Databases, Factual; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012306:Risk; D012307:Risk Factors; D015607:Stents; D020521:Stroke / Q000401:mortality / Q000517:prevention & control; D016896:Treatment Outcome
keywords: carotid stenosis; carotid stenting; prevention