Carotid artery stenting—evolution of a technique to rival carotid endarterectomy

Abstract

t b e o t o t is now nearly 20 years since angioplasty was first performed to treat carotid artery stenosis in the early 1980s. Since then, the technology available for carotid ndovascular treatment (angioplasty or stenting) has adanced considerably. Despite these advances, the use of ngioplasty and stenting to treat carotid stenosis has reained controversial. Part of the reluctance to use endoascular techniques has arisen from anxiety about the isks of stroke resulting from embolization of thrombus r atheromatous debris while the stenosis is being treated. number of experimental studies have established that mbolization of small particles during carotid endovasular procedures is common, whether measured by ranscranial Doppler in the catheter suite or in bench odels (1–3). It has also been shown that microemboliation during carotid angioplasty is considerably more requent than during carotid endarterectomy (2), partly ecause the surgeon protects the brain from embolizaion by clamping the carotid artery during an endarterecomy. However, although embolization of small particuate matter is almost universal in the experimental ituation, it causes symptoms less often. In early case seies of carotid angioplasty and stenting, the rate of stroke ssociated with endovascular treatment was similar to hat recorded in the randomized trials of carotid surgery 4). Moreover, detailed neuropsychological testing did ot show any significant impairment of cognitive funcion in patients treated by endovascular techniques in the bsence of stroke (5). One of the arguments against carotid stenting is that he alternative technique of carotid endarterectomy has een shown to be highly effective in the two large ranomized clinical trials of carotid surgery (6). However, here are several advantages of endovascular techniques ompared with surgery, including a reduction in the rate f myocardial infarction and the avoidance of an incision n the neck, which can cause cranial nerve injury and ound hematoma. Endovascular techniques have the ad-