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Background Carotid artery stenting (CAS) has been advocated as an alternative to carotid endarterectomy (CEA) in high-risk surgical patients, including stenosis after CEA. This study compared early and midterm clinical outcomes for primary CAS vs CAS for post-CEA stenosis. Methods This study analyzed 180 high-risk surgical patients: 68 had primary CAS (group A), and 112 had CAS for post-CEA stenosis (group B). Patients were followed-up prospectively and had duplex ultrasound imaging at 1 month and every 6 months thereafter. All patients had cerebral protection devices. Kaplan-Meier life-table analysis was used to estimate rates of freedom from stroke, stroke-free survival, ≥50% in-stent stenosis, ≥80% in-stent stenosis, and target vessel reintervention (TVR). Results Patients had comparable demographic and clinical characteristics. Carotid stent locations were similar. Indications for CAS were transient ischemic attacks (TIA) or stroke in 50% for group A and 45% for group B. The mean follow-up was comparable, at 21 (range, 1-73) vs 25 (range, 1-78) months, respectively. The technical success rate was 100%. The perioperative stroke rates and combined stroke/death/myocardial infarction (MI) rates were 7.4% for group A vs 0.9% for group B ( P = .0294). No perioperative MIs occurred in either group. One death was secondary to stroke. The combined early and late stroke rates were 10.8% for group A and 1.8% for group B ( P = .0275). The stroke-free rates at 1, 2, 3, and 4 years for groups A and B were 89%, 89%, 89%, and 89%; and 98%, 98%, 98%, and 98%, respectively ( P = .0105). The rates of freedom from ≥50% carotid in-stent stenosis were 94%, 83%, 83%, and 66% for group A vs 96%, 91%, 83%, and 72% for group B ( P = .4705). Two patients (3%) in group A and seven patients (6.3%) in group B had ≥80% in-stent stenosis (all were asymptomatic except one). The freedom from ≥80% in-stent stenosis at 1, 2, 3, and 4 years for groups A and B were 100%, 98%, 98%, and 78% vs 99%, 96%, 92%, and 87%, respectively ( P = .7005). Freedom from TVR rates at 1, 2, 3, and 4 years for groups A and B were 100%, 100%, 100%, and 100% vs 99%, 97%, 97%, and 92%, respectively ( P = .261). Conclusions CAS for post-CEA stenosis carried a lower risk of early postprocedural neurologic events than primary CAS, with a trend toward a higher restenosis rate during follow-up.

Background The optimal duplex ultrasound (DUS) velocity criteria to determine in-stent carotid restenosis are controversial. We previously reported the optimal DUS velocities for ≥30% in-stent restenosis. This prospective study will further define the optimal velocities in detecting various severities of in-stent restenosis: ≥30%, ≥50%, and 80% to 99%. Methods The analysis included 144 patients who underwent carotid artery stenting as a part of clinical trials. All patients had completion arteriograms and underwent postoperative carotid DUS imaging, which was repeated at 1 month and every 6 months thereafter. Patients with peak systolic velocities (PSVs) of the internal carotid artery (ICA) of ≥130 cm/s underwent carotid computed tomography (CT)/angiogram. The PSVs and end-diastolic velocities of the ICA and common carotid artery (CCA) and the PSV of the ICA/CCA ratios were recorded. Receiver operating characteristic curve (ROC) analysis was used to determine the optimal velocity criteria for the diagnosis of ≥30, ≥50, and ≥80% restenosis. Results The mean follow-up was 20 months (range, 1-78 months). Available for analysis were 215 pairs of imaging (DUS vs CTA/angiography) studies. The accuracy of CTA vs carotid arteriogram was confirmed in a subset of 22 patients (κ = 0.81). The ROC analysis demonstrated that an ICA PSV of ≥154 cm/s was optimal for ≥30% stenosis with a sensitivity of 99%, specificity of 89%, positive-predictive value (PPV) of 96%, negative-predictive value (NPV) of 97%, and overall accuracy (OA) of 96%. An ICA EDV of 42 cm/s had sensitivity, specificity, PPV, NPV, and OA in detecting ≥30% stenosis of 86%, 62%, 87%, 60%, and 80%, respectively. An ICA PSV of ≥224 cm/s was optimal for >50% stenosis with a sensitivity of 99%, specificity of 90%, PPV of 99%, NPV of 90%, and OA of 98%. An ICA EDV of 88 cm/s had sensitivity, specificity, PPV, NPV, and OA in detecting ≥50% stenosis of 96%, 100%, 100%, 100%, 53%, and 96%. An ICA/CCA ratio of 3.439 had sensitivity, specificity, PPV, NPV, and OA in detecting ≥50% stenosis of 96%, 100%, 100%, 100%, 58%, and 96%, respectively. An ICA PSV of ≥325 cm/s was optimal for >80% stenosis with a sensitivity of 100%, specificity of 99%, PPV of 100%, NPV of 88%, and OA of 99%. An ICA EDV of 119 cm/sec had sensitivity, specificity, PPV, NPV, and OA in detecting ≥80% stenosis of 99%, 100%, 100%, 100%, 75%, and 99%, respectively. The PSV of the stented artery was a better predictor for in-stent restenosis than the end-diastolic velocity or ICA/CCA ratio. Conclusion The optimal DUS velocity criteria for in-stent restenosis of ≥30%, ≥50%, and ≥80% were the PSVs of 154, 224, and 325 cm/s, respectively.