Correlation of Duplex Ultrasound Velocities and Arteriography Following Carotid Artery Angioplasty and Stenting

Santiago Chahwan, MD, Todd Miller, MD, John P. Pigott, MD, Dennis Wojnarowski and Anthony J. Comerota, MD
Jobst Vascular Center, The Toledo Hospital, Toledo, OH

Objectives: Correlation between carotid duplex ultrasound (DUS) flow velocities and carotid artery stenosis in the post-carotid endarterectomy patient is well established. Now, with the evolution toward catheter-based technologies, carotid stenosis is being treated with angioplasty and stenting (CAS). CAS changes vessel wall compliance and blood flow within the stented portion of the artery. Differing opinions exist as to whether DUS is a reliable tool to assess post-intervention technical outcome after CAS. The purpose of this study is to evaluate the immediate and early correlation between DUS flow velocities and arteriographic technical outcome after CAS.
Methods: Data from 66 carotid arteries in 59 patients treated with CAS at a single center from November 2000 to January 2006 were retrospectively reviewed. Pre-intervention and post-intervention DUS and carotid arteriogram data were evaluated for each patient. Peak systolic velocity (PSV) and end diastolic velocity (EDV) were analyzed for clinical correlation with the post-intervention arteriogram and subsequent arteriography.
Results: Average pre-intervention PSV was 390 cm/sec (+/- 110), with a range 216-691, and average EDV was 134 cm/sec (+/- 51), with a range 35-271. Post-intervention DUS was obtained a mean of 5 days post CAS (range 1-30). The average post-intervention PSV was 102 cm/sec (+/- 41), with a range of 30-184, and average EDV was 29 cm/sec (+/-18), with a range 16-50. In 57 carotid arteries (86%), DUS obtained after CAS demonstrated normal velocities, which corresponded with post-intervention arteriography. Nine carotid arteries (14%) demonstrated velocity criteria consistent with a 50% stenosis, which also correlated with residual stenoses found on the completion arteriogram. Two patients (3 arteries) developed recurrent stenoses requiring re-intervention during follow-up. The restenoses detected by DUS were confirmed by arteriography in each patient. Post re-intervention DUS velocities were normal, as were the completion arteriograms.
Conclusions: DUS flow velocities following CAS correlate well with arteriographic results and can be used reliably to assess immediate technical outcomes of CAS, follow patients for recurrent stenosis, and identify patients who might require further intervention. DUS criteria do not need to be modified to identify stenosis following CAS.