To examine the association between operator or hospital volume and procedural outcomes of carotid revascularization.
Operator and hospital volume have been proposed as determinants of outcome after carotid endarterectomy (CEA) or carotid artery stenting (CAS). The magnitude and clinical relevance of this relationship are debated.
We systematically searched PubMed and EMBASE until August 21, 2017. The primary outcome was procedural (30 days, in-hospital, or perioperative) death or stroke. Obtained or estimated risk estimates were pooled with a generic inverse variance random-effects model.
We included 87 studies. A decreased risk of death or stroke following CEA was found for high compared to low operator volume with a pooled adjusted odds ratio (OR) of 0.50 (95% confidence interval [CI] 0.28–0.87; 3 cohorts), and a pooled unadjusted relative risk (RR) of 0.59 (95% CI 0.42–0.83; 9 cohorts); for high compared to low hospital volume with a pooled adjusted OR of 0.62 (95% CI 0.42–0.90; 5 cohorts), and a pooled unadjusted RR of 0.68 (95% CI 0.51–0.92; 9 cohorts). A decreased risk of death or stroke after CAS was found for high compared to low operator volume with an adjusted OR of 0.43 (95% CI 0.20–0.95; 1 cohort), and an unadjusted RR of 0.50 (95% CI 0.32–0.79; 1 cohort); for high compared to low hospital volume with an adjusted OR of 0.46 (95% CI 0.26–0.80; 1 cohort), and no significant decreased risk in a pooled unadjusted RR of 0.72 (95% CI 0.49–1.06; 2 cohorts).
We found a decreased risk of procedural death and stroke after CEA and CAS for high operator and high hospital volume, indicating that aiming for a high volume may help to reduce procedural complications.
This systematic review has been registered in the international prospective registry of systematic reviews (PROSPERO): CRD42017051491.
*Department of Vascular Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
†Nuffield Department of Surgical Sciences, Level 6 John Radcliffe Hospital, University of Oxford, Oxford, UK
‡Medical Research Council Population Health Research Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
§Clinical Trial Service Unit and Epidemiological Studies Unit, Nuffield Department of Population Health, University of Oxford, Oxford, UK
¶Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
Reprints: Gert J. de Borst, MD, PhD, Department of Vascular Surgery, University Medical Center, Room G04.129, PO Box 85500, 3508 GA Utrecht, The Netherlands. E-mail: G.J.deBorstfirstname.lastname@example.org.
M.H.F.P. and E.C.B. contributed equally to this article and share first authorship.
Funding: Professor Halliday's research is funded by the UK Health Research (NIHR) Oxford Biomedical Research Centre (BRC). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health.
The authors declare no conflict of interests.
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