Carotid artery tandem lesions: frequency of angiographic detection and consequences for endarterectomy.

BACKGROUND AND PURPOSE Several prospective trials have shown that ischemic stroke can be prevented by performing an endarterectomy in patients with high-grade carotid stenosis. Our purpose was to ascertain the frequency of carotid artery tandem lesions and to determine whether their presence alters the surgeon's decision to perform an endarterectomy. METHODS We retrospectively reviewed the cerebral angiograms obtained between January 1994 and June 1996 in 853 patients with carotid occlusive disease. Studies were analyzed for the presence of internal carotid artery (ICA) stenosis as well as for tandem lesions (defined as > or = 50% diameter stenosis) within the common carotid artery, carotid siphon, or proximal intracranial arteries. The frequency of intracranial saccular aneurysms was determined. RESULTS Six hundred seventy-two of the 853 patients had a carotid bifurcation stenosis of 70% or greater or underwent an endarterectomy. Of these, a carotid siphon stenosis of 50% or greater was noted in 65 patients (9.7%) and was ipsilateral to an ICA stenosis in 37 patients (5.5%). A common carotid stenosis was present in 29 patients (4.3%), ipsilateral to an ICA stenosis in 14 patients (2.1%). A stenosis of 50% or greater within the proximal intracranial circulation was present in 28 patients (4.2%), ipsilateral to an ICA stenosis in 15 patients (2.2 %). Four patients had tandem stenoses at more than one site. Tandem stenoses in the siphon or intracranial segments were noted in 13.5% with a bifurcation stenosis and in 8.8% of those with no bifurcation stenosis. Endarterectomy was performed in 48 of the 66 patients with tandem stenotic lesions. CONCLUSION The presence of a tandem lesion infrequently alters the surgeon's decision to perform an endarterectomy. However, the importance of detecting tandem stenoses cannot be underestimated, since they may have important implications for long-term medical management in symptomatic patients.