Objectives: To determine whether there is any evidence of a systematic reduction in the operative risk of carotid endarterectomy (CEA) for symptomatic stenosis in recent years.
Methods: We performed a systematic review of all studies published between 2000 and 2008 inclusive that reported the risks of stroke and death for symptomatic carotid stenosis. We compared the reported risks with our previous review of studies published prior to 2001 and between studies that were reported by surgeons alone and studies that included neurologists or stroke physicians as assessors/authors, with particular reference to the proportion of operative strokes to operative deaths.
Results: Of 494 studies, only 53 reported operative risks for patients with symptomatic stenosis separately. In keeping with the findings of our previous review, the pooled operative risk of stroke and death reported in studies published by surgeons alone (3.9%, 95% confidence interval (CI): 3.4-4.3) was significantly lower (p<0.001) than that reported in studies that involved neurologists (5.6%, 95% CI: 5.1-6.2). The pooled ratio of operative stroke:operative death was 4.0 (range: 3.6-4.5) in studies involving neurologists or stroke physicians and 2.7 (range: 2.1-3.9) in studies involving only surgeons (p=0.002). We found no evidence of a reduction in published risks of death or stroke and death due to CEA for symptomatic carotid stenosis between 1985 and 2008. Indeed, the 1.4% (range: 1.2-1.6%) pooled operative mortality in studies published during 2001-2008 was significantly higher than that reported in ECST and NASCET (1.0%, 95% CI: 0.9-1.1%). However, the average age of patients having CEA has continued to increase during this period.
Conclusions: There is no evidence of a systematic reduction over the last decade in the published risks due to CEA for symptomatic stenosis. The lower proportion of non-fatal operative strokes in surgeon-only studies suggests that some minor operative strokes have been missed.