Value of US in selecting patients for carotid angioplasty and stent placement

Editor: I read with interest the article entitled “Carotid Angioplasty and Stent Placement: Comparison of Transcranial Doppler US Data and Clinical Outcome with and without Filtering Cerebral Protection Devices in 509 Patients” by Dr Vos and colleagues in the February 2005 issue of Radiology (1). In the study by these authors, there was a demonstration of an association between the volume of microemboli and macroemboli in association with protection devices for patients who underwent angioplasty and stent placement. The article is of great importance, but it did not include the considerable work that has been done regarding plaque characterization, plaque instability, and the presence of intraplaque hemorrhage within plaque. With ultrasonography (US), plaque has been successfully classified as heterogeneous or homogeneous, with heterogeneous plaque being associated with intraplaque hemorrhage and instability (2–10). It would have been interesting for the authors to have classified the plaque prior to angioplasty and stent placement to determine if there was a higher incidence of microor macroemboli in heterogeneous plaque when angioplasty and stent placement were performed. It would seem that in combining the work by these authors and the information in the literature on US there would be a safe subgroup of patients who have homogeneous plaque, who should undergo angioplasty and stent placement. This is the majority of patients.