Associates In Surgery, PA  -  Conway South Carolina

Asymptomatic Carotid Stenosis

Four recent trials concerning carotid endarterectomy have been completed. The first three including, the Carotid Artery Stenosis with Asymptomatic Narrowing Operation Versus Aspirin (CASANOVA) Study, the Mayo Asymptomatic Carotid Endarterectomy Trial (MACE), and the Veterans Administration (VA) Cooperative Trial on Asymptomatic Carotid Stenosis, yielded inconclusive results.

Asymptomatic carotid stenosis >60% medical versus surgical therapy aggregate risk of ipsilateral (same side) stroke.

The largest trial concerning the management of asymptomatic carotid stenosis (ACAS), however, reached a stopping rule, and the data were released to coinvestigators in September of 1994. One thousand six hundred sixty two patients were entered in the ACAS trial at 39 centers. All patients had greater than 60% stenosis of the carotid artery and were randomized to either medical treatment with 325 mg of aspirin daily, or aspirin plus carotid endarterectomy. The primary endpoints of this study were stroke ipsilateral to the carotid stenosis or death within thirty days of randomization. The aggregate risk for the primary outcome in the medical group was 10.6% versus 4.8% in the surgical group. Carotid endarterectomy provided a statistically significant benefit with an absolute risk reduction of 5.8%, and a relative risk reduction of 55% in the risk of the primary endpoint of stroke within five years. The benefit was greater in men, with a 69% relative risk reduction compared to a 16% risk reduction in women. These positive results were dependent on the operation being performed in medical centers where the surgeon had a documented perioperative morbidity and mortality of 3%.

A Multidisciplinary Consensus Statement from the American Heart Association concluded that carotid endarterectomy, performed in medical centers with documented combined perioperative morbidity and mortality for asymptomatic endarterectomy of less than 3%, in conjunction with aggressive modifiable risk factor management is beneficial for patients who have an asymptomatic stenosis exceeding 60% diameter reduction confirmed by angiography.

Carotid endarterectomy asymptomatic stenosis >60% relative risk reduction