Angioplasty and Stent Placement in Symptomatic Internal Carotid Occlusion

Abstract

Conclusion: Carotid artery angioplasty and stenting can be successfully performed in patients with internal carotid artery pseudo-occlusion or string sign. Summary: This report focuses on carotid angioplasty and stenting in a series of patients in whom the internal carotid artery (ICA) was thought occluded by conventional ultrasound but who actually had string signs. The authors treated 16 patients. Contrast computed tomography (CT) showed a patent distal ICA in 14 of the 16 patients treated. Contrast-enhanced ultrasound imaging also showed patent distal ICAs in 13 cases. This is actually a series of very high-grade ICA stenosis and/or string signs treated with angioplasty and stenting. The authors performed the angioplasty and stent placement under cerebral protection. Duplex imaging was performed at 14 days, 3 months, and every 6 months thereafter. CT scans were obtained at 2 to 9 months, and the mean follow-up period was 9.9 months. Most patients had nonhemispheric symptoms as the indication for treatment. Patients were treated with clopidogrel and aspirin before the procedure and were maintained on clopidogrel 90 days after treatment and on aspirin indefinitely. A 6F sheath was placed in the common carotid artery and the ICA accessed with a 5F diagnostic vertebral catheter. A 0.035-inch hydrophilic guide wire was then passed into the ICA, followed by the catheter. An interceptor filter (Medtronic, Minneapolis, MN) was passed through the catheter and opened in the lumen, and then the catheter was withdrawn. Predilation was performed with a 3-mm balloon through the filter wire, and then a self-expanding stent was placed in the proximal ICA and dilated with a 5-mm balloon. If necessary, a second distal stent was placed. Stent placement was successful in 13 of 16 patients. There were no deaths, conversions, or cardiac complications. One patient had paresis in the upper limb with recovery in 3 months. At follow-up, all 13 patients remained with patent arterial lumens and were symptom free. After 2 to 9 months, so-called string signs had calibers close or equal to those of normal arteries. Comment: The title of this article is misleading. Although conventional duplex ultrasound imaging showed the patients had occluded ICAs, all in fact had patent distal ICAs either by contrast-enhanced ultrasound or contrast CT scanning. The authors of the article, the Journal of Vascular and Interventional Radiology reviewers, and the editors should be ashamed for permitting such a misleading title. What the authors have shown us is that in their institution, conventional duplex ultrasound imaging is likely below standard in distinguishing high-grade carotid stenosis from occlusion. They have shown us that CT angiography and contrast-enhanced ultrasound imaging can detect carotid string signs, something we already knew. They have also shown us that if you can get a wire across a high-grade stenosis, then you can perform angioplasty and stenting, again something we already knew. They have demonstrated that such procedures can be performed, but whether they should be performed is an entirely different question.