Risk factors for complications after carotid endarterectomy--a population-based study.

OBJECTIVES

The overall benefit of carotid endarterectomy (CEA) is dependent on the outcome from the procedure. However, many reports are from selected centres and not population-based. The aim of this study was to assess the 30-day complication rate for a whole country and also to determine independent risk factors for serious complications.

MATERIALS AND METHODS

One thousand five hundred and eighteen CEA were retrospectively reviewed, covering principally all the CEAs in Sweden, during a three year period. Indications for surgery were; minor stroke 34%, TIA 34%, amaurosis fugax 18%, asymptomatic 11% and others 3%. Data were collected from the Swedish Vascular Registry (Swedvasc). Combined cohort and case-control methodology was used.

RESULTS

Registered complications were; 43 permanent strokes, 32 transient strokes (<30 days), 18 TIA/amaurosis fugax and 22 deaths (seven fatal stokes). In the cohort study, the 30-day permanent stroke and death rate were 4.3% (65/1518). Significant risk factors in multivariate analyses were the indication for surgery (minor stroke vs. other indications) (p=0.02, RR=1.38), diabetes (p=0.02, RR=1.41), cardiac disease (p<0.01, RR 1.43) and operation at a university hospital (p=0.02, RR=1.39). In the case-control study comparing the 65 cases of permanent stroke and/or death with 130 matched controls the only significant risk factor was contralateral occlusion (p<0.01, OR=5.27). One patient (1/130) with a permanent stroke was wrongly reported as a local neurological complication (facial paresis).

CONCLUSION

This national audit demonstrated population-based data on complication rates after CEA well comparable with previous randomised trials. The validity of the Swedvasc data was confirmed. Combined cohort and case-control methodology was useful in analysing risk factors for serious perioperative complications.