CAROTID-ARTERY STENTS - EARLY AND INTERMEDIATE FOLLOW-UP WITH DOPPLERUS

PURPOSE: To determine whether ultrasound (US) is a sensitive follow-up method after placement of a carotid artery stent for the detection of significant stenosis, occlusion, and other complications at early and intermediate follow-up.MATERIALS AND METHODS: Doppler US examinations were performed after stent placement in 170 carotid arteries in 119 p atients with angiographic correlation. Prospective diagnostic US crite ria for stenosis were peak-systolic velocity greater than 1.25 m/sec, internal carotid artery (TCA) to common carotid artery (CCA) peak-syst olic velocity ratio of greater than or equal to 3:1, and intrastent do ubling of peak-systolic velocity. Retrospective criteria for stenosis were also applied: peak-systolic velocity greater than 1.7 m/sec, ICA end-diastolic velocity greater than 0.4 m/sec, ICA/CCA peak-systolic v elocity ratio greater than 2.0, and ICA/CCA end-diastolic velocity rat io greater than 2.4. RESULTS: Eighty-seven immediate and 83 intermedia te (average, 7.3 months) follow-up US examinations were performed. Two stent occlusions were detected. One or more prospective US criteria w ere abnormal in 26 arteries with a stent. One or more retrospective cr iteria were positive in 47 arteries. Angiography showed corresponding findings, with only one significant stenosis (63%) in the ICA stents. Moderate collapse of a CCA stent was depicted at US. CONCLUSION: Only one significant recurrent stenosis was detected, and no significant st enoses were missed at US. US successfully depicted carotid artery sten t occlusion and a moderate stent collapse. Sensitivity in the detectio n of intrastent stenosis is promising. Further study to refine US crit eria in a study with longer term follow-up is needed owing to the lack of significant recurrent stenosis in the intermediate follow-up group .