Duplex–assisted internal carotid artery balloon angioplasty and stent placement: A novel approach to minimize or eliminate the use of contrast material

Abstract

Carotid artery balloon angioplasty and stenting (CBAS) is emerging as an acceptable alternative to carotid endarterectomy in selected high-risk patients. Conversely, patients with pre-existing renal impairment, diabetes, or both may be harmed by the nephrotoxic contrast agents required during CBAS. We attempted to limit or eliminate the use of contrast material during CBAS. Eighteen patients with severe carotid stenoses (>70%) underwent CBAS at our institution over the last 12 months with duplex scan-assisted CBAS. Of these, 12 were primary procedures, and 6 were performed for carotid re-stenosis. Fourteen patients (78%) were neurologically asymptomatic. The average age of these patients was 75 +/- 11 years (range, 44-92 years). Hypertension, chronic renal insufficiency (serum creatinine level > or =1.5 mg/dL), coronary artery disease, diabetes, and smoking were present in 89%, 67%, 59%, 33%, and 28% of patients, respectively. Preoperative duplex carotid mapping was performed in all cases. All procedures were performed with patients under local anesthesia and light sedation. An ATL HDI 5000 scanner with the SonoCT feature was used. The common femoral artery was cannulated with a single-entry needle under direct ultrasound visualization. Fluoroscopy was used to assist passage of the guidewire into the aorta and the common carotid artery. In only four cases (22%) was an aortic arch angiogram obtained. Selective catheterization of the internal and external carotid arteries was performed under ultrasound guidance. The distal cerebral protection device (17 cases) was placed under fluoroscopic guidance. Balloon width and length were chosen according to ultrasound measurements. Balloon and stent deployment were successfully achieved with ultrasound guidance alone in all cases. Appropriate stent apposition and resolution of the stenosis was confirmed by duplex scanning in all cases. Five patients (28%) were noted to have low (<100 mL/min) internal carotid artery volume flow after stent deployment (range, 20-88 mL/min; mean +/- SD, 50 +/- 25 mL/min). The internal carotid artery volume flow increased immediately after Filterwire retrieval in all cases and ranged from 136 to 400 mL/min (mean, 245 +/- 107 mL/min). This increase was statistically significant ( P < .02). No ipsilateral strokes or deaths occurred during follow-up from 1 to 12 months (mean follow-up, 5 months). Duplex scan-assisted CBAS is feasible and may reduce the need for intra-arterial contrast injection in selected patients deemed at high risk for renal failure from nephrotoxic contrast material. Additional advantages include direct visualization of the puncture site, precise position of the balloon and stent, and B-mode and hemodynamic confirmation of the adequacy of the technique.