Volume 36, Issue 3 , Pages 265-266, September 2008
Invited Commentary on “Carotid Stenting versus Carotid Endarterectomy: Evidence Base and Cost Implications
Article Outline
This paper, like others before it, concludes that carotid stenting (CAS) is less cost-effective than carotid endarterectomy (CEA). As a surgeon, this appeals to my own prejudices, but will it stand up to the more critical gaze of enthusiastic stenters?
The authors have developed a cost-effectiveness model based on procedural costs for both CEA and CAS in their own institutions in the Netherlands and clinical outcomes from the ECST,1 a Cochrane Review of randomised controlled trials2 (RCTs) and the Global Carotid Artery Stent Registry (Wholey3). The crucial questions are 1) Do the costs in this paper reflect wider practice? 2) Are the clinical outcomes used by the authors reasonable?
The issue of costs is relatively straightforward. By providing a breakdown of how these were calculated (Table 1), we can all compare and contrast with our own figures. The paper overestimates CEA costs for my own unit as we discharge patients within 48 hours of operation, don't use TCD and in the UK an interventional radiologist costs roughly the same as a surgeon, rather than half as much (though I like the Dutch valuation). We don't run a stenting programme but those that do will no doubt find similar faults with the CAS costs. However, it does seem clear that the kit used for CAS is considerably more expensive than that used for CEA. So, if the benefit of a shorter hospital stay is lost, do the clinical outcomes of CAS justify this additional expense?
This rather polarised debate boils down to which outcomes you choose to believe. For those you don't like you can always invoke the “learning curve”, “evolving techniques” or “my own results”.
By basing their model on results from the ECST (an old trial), Cochrane database (disputed trials) and the Wholey registry (not a trial) the authors will be subjected to familiar criticisms. They have, however, used the best available evidence. By using different scenarios and sources of data they have endeavoured to do this in an even-handed way. The crucial figure (fig. 3) in this paper, comparing costs and QALYs, finds the Cochrane RCTs showing a clear advantage for CEA, with the Wholey database winning the argument for CAS over ECST (in what could be argued was a rather uneven contest). Both sides will draw comfort from this, but how were such conflicting results obtained? The explanation is found in Figure 1, where the confidence intervals for major and minor stroke rates following CAS in the Cochrane trials and the Wholey registry do not even come close to overlapping. The learning curve or selective reporting? You decide.
What this paper contributes is a useful model into which individual centres can put their own figures. Differing local costs and outcomes will make the case for one technique or the other. It is incumbent on manufacturers of stenting equipment to also look long and hard at these figures. In any normal marketplace if an expensive technology has no proven advantage over a cheaper alternative, producers would be forced to cut prices or go out of business. But the healthcare economy is not a normal marketplace and clinicans are rarely swayed by economic arguments. If we were, this paper suggests that we should no longer be debating this subject.
References
- . Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet. 1998;351:1379–1387
- . Percutaneous transluminal angioplasty and stenting for carotid artery stenosis. Cochrane Database Syst Rev. 2007;4:CD000515
- . Updated review of the global carotid artery stent registry. Catheter Cardiovasc Interv. 2003 Oct;60(2):259–266
PII: S1078-5884(08)00337-7
doi:10.1016/j.ejvs.2008.06.014
© 2008 European Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Volume 36, Issue 3 , Pages 265-266, September 2008
