Background: Conventional carotid artery stenting (CAS) with administration of contrast media carries a risk of adverse reactions such as contrast media-induced nephropathy or an allergic reaction.
Objective We aimed to present a novel technique, that is, duplex-assisted CAS without administration of contrast media and validate its safety and feasibility.
Methods: Fifteen patients with severe carotid stenosis (≥70 %) associated with chronic kidney disease (CKD) (stage ≥3) or allergy to contrast media underwent duplex-assisted CAS without administration of contrast media. The embolic protection device (EPD) placed in the common carotid artery (CCA) was clearly visible on the longitudinal section (Fig. A) and was then advanced into the internal carotid artery (ICA) by duplex-guidance (Fig. B). When starting the delivery of the stent, the position of the distal stent end is confirmed by duplex monitoring (Fig. C). Postdilatation was performed after the stent (Fig. D arrowheads) deployment if enough expansion of the carotid artery was not achieved. Adequate stent position (Fig. E arrowheads) and technical success was confirmed by duplex images and intravascular ultrasound (Fig. F). Conventional CAS was also performed in 165 patients and used as the control group.
Results: The technical success rate was 100 % in duplex-assisted CAS group. Combined stroke or death rates during the post-procedural period did not differ significantly between the duplex assisted CAS group (0/15, 0 %) and conventional CAS group (4/165, 2.4 %). None of the 14 patients with CKD in the duplex-assisted CAS group experienced further deterioration of renal function.
Conclusion: This method seemed to be a safe and effective treatment for patients with CKD or an allergy to contrast media. The most important factor for the indication of duplex-assisted CAS was to obtain the clear visualization of the luminal narrowing with minimal calcification on the longitudinal section of the duplex ultrasonography.