[Treatment of carotid stenosis: carotid surgery or stent? In favor of operation].

BACKGROUND

According to international studies (ACAS, NASCET, ECST, ACST) the discussion concerning the indication for an operative treatment of carotid artery stenosis which lasted over years, may be regarded as completed. The impressive results showed that the operative treatment is of less risk for the patient than the natural history. But is this conclusion also true for carotid artery stenting? Comparative studies are running, but are not completed yet. The treatment of carotid stenosis by operative or interventional means is controversial, since conflicting conclusions have been drawn from the correlation between plaque morphology and the patients' embolic risk. We clearly recommend treatment by carotid endarterectomy and discourage angioplasty and stenting except in controlled and randomized studies.

METHODS AND RESULTS

In a prospective study of patients with carotid artery stenoses, we compared plaque morphology, as examined by ultrasound, with the histological diagnosis. We found that plaque morphology (soft vs. hard plaques) cannot adequately predicted, since in only 80% of cases the noninvasively suspected plaque morphology could be confirmed. In contrast, the accuracy for the estimation of the degree of stenosis was excellent with 98%. In the case of stroke in progression and completed stroke, histological examination found ulcerations in 72% of patients, whereas ultrasound had detected these ulcerations in only 53%. A significantly higher number of transient ischemic attacks and strokes occurred in patients with soft plaques as compared to asymptomatic patients, who tend to present with hard plaques. Patients with soft plaques seem to have a higher risk of postoperative permanent neurological deficit. Dangerous plaque formation with thrombotic or ulcerous material was not accurately detected by ultrasound. Therefore the risk of embolisation cannot be predicted efficiently by means of duplex scanning, which, however, is especially important for carotid stenting. High intensity transient signals (HITS) were detected by transcranial Doppler during carotid endarterectomy and carotid stenting. A significant higher number of HITS was found in dangerous plaque formations like ulcerations or thrombotic formations. The number of HITS during carotid angioplasty and stenting was eight to ten times higher than in the worst group during operation.

CONCLUSION

Due to the insufficient knowledge about the benefit of carotid stenting, these observations are indicating that surgery on the carotid artery is not comparable to interventional treatment and remains the gold standard, until the results of prospective randomized trials will demonstrate an equivalent outcome.