Dear Editor-in-Chief:

I wish to congratulate Eric Russell for his conscientious and thought-provoking commentary on the status of carotid stenting. The technique of carotid stenting is about to begin a new phase of additional rigorous scrutiny and investigation. The National Institute of Neurologic Disorders and Stroke (NINDS) recently has approved and funded a large multicenter, multinational, randomized, controlled trial comparing carotid stenting with carotid endarterectomy. The Carotid Revascularization Endarterectomy vs. Stent Trial (CREST) plans to begin training and credentialing interventionalists this summer, and recruitment is expected to begin late this year or in early 2000. The trial will address the relevant efficacy of carotid stenting and carotid endarterectomy in a North American Symptomatic Carotid Endarterectomy Trial (NASCET)-like population of patients with symptomatic high-grade stenoses. We anticipate that 2500 patients will need to be recruited to satisfy the statistical requirements of the study. It is essential that this landmark trial have the full involvement of and commitment from the neuroradiologic community.

This landmark trial is the initiative of a neuroradiologist, Robert Ferguson, Chairman of the Department of Radiology at Queens University Hospital in Kingston, Ontario. After his pivotal work in organizing the North American Cerebral Percutaneous Transluminal Angioplasty Registry (NACPTAR), Dr. Ferguson collaborated with Robert Hobson, Director of Vascular Surgery at the New Jersey Medical School, Newark, New Jersey and the principal investigator of the VA Cooperative Trial of Endarterectomy, as well as with me and others, to form the CREST Trial group. Indeed, neuroradiologists have been instrumental in the rapid development and current success of this technique. Beginning with the pivotal and ongoing work of Jacques Theron in Caen, France and the pioneering contributions of Jiri J. Vitek at the University of Alabama at Birmingham, the technique has now gained wide acceptance. Eric Russell diminishes the rigor of the well-planned IRB-approved clinical trials that were begun at the University of Alabama at Birmingham in 1994 (1). The results of these well-conducted and critically audited prospective registries provided the clinical findings that gained the acceptance of physicians throughout the world and, more importantly, industry support, without which, further device and technique development would have been impossible. Most importantly, study participants were subjected to independent neurologic evaluation 24 hours postprocedurally, a standard to which the NASCET has never been held. The statement that no long-term outcome information is available is incorrect. Late results have been reported, and multiple groups now have confirmed the rarity of neurologic events after stent intervention (2). Similarly, our experience has been analyzed carefully in terms of risk stratification on the basis of clinical symptoms and morphologic characteristics of lesions (3). Similarly, a great deal of information has been promulgated concerning the use of coronary wires and balloons to cross and predilate high-grade lesions. Furthermore, cerebral protection during stent placement is an active area of investigation, and current carotid stent symposia have focussed on a variety of new devices designed to provide cerebral protection. The political, regulatory, and reimbursement ramifications of this technique remain beyond our control. We consider the definition of carotid stenting as a significant-risk procedure to be quite arbitrary. This definition ignores the 6% incidence of death and stroke that occurs with carotid endarterectomy (4). In our most recent experience, we have completed 136 procedures with no deaths, no major strokes, and a 1.6% incidence of minor nondisabling strokes. In our institution, the neurologist would like to consider carotid stenting as the standard of care for their patients, but this technique remains incorrectly labeled as high-risk, federally unapproved, and nonreimbursable.

At least one prospective, randomized, controlled trial has been completed comparing carotid angioplasty (stenting in 1 of 3 of cases), to carotid endarterectomy. This trial compared the learning curve of the radiologists involved against the mature results of experienced vascular surgeons in major regional centers. The results from CAVATAS have been reported and will be published soon. There was no difference between the incidence of minor or major neurologic events in this randomized trial. I am confident that the CREST study will validate the results that have emerged from numerous registries throughout the world. The results of CREST, however, will not be available for at least 6 years. In the meantime, the CREST group will be conducting, with the NINDS and the FDA, industry-supported, rigorous, prospective registry studies in the very large population of patients who will never and can never be studied in prospective, randomized trials. Neuroradiologic involvement in carotid stenting has been pivotal in its development, and will continue to be essential if the procedure is to emerge as it should as a safer, more comfortable, and less invasive alternative to carotid endarterectomy.