Carotid Artery Stenting and Endarterectomy Compared
Abstract & Commentary
By John J. Caronna, MD, Vice-Chairman, Department of Neurology, Cornell University Medical Center, Professor of Clinical Neurology, NewYork-Presbyterian Hospital. Dr. Caronna reports no financial relationship relevant to this field of study.
Synopsis: In this retrospective case-control study, carotid stenting with cerebral protection and carotid endarterectomy were not significantly different in early morbidity and mortality.
Source: Cao P, et al. Outcome of Carotid Stenting Versus Endarterectomy: A Case-Control Study. Stroke. 2006;37:1221-1226.
Carotid artery angioplasty with stenting (CAS) has been accepted by many physicians and most patients as a less invasive alternative to carotid endarterectomy (CEA) for the primary and secondary prevention of stroke related to internal carotid artery (ICA) stenosis. The clinical use of CAS has steadily increased despite initial outcome studies that indicated higher morbidity and mortality rates for CAS than for CEA.1
Cao and colleagues report the perioperative and midterm (up to 36 months of follow-up) results of CAS vs CEA in a retrospective, matched case-control study at a single tertiary care hospital in Italy. The primary criterion for treatment was severe ICA stenosis, either symptomatic or asymptomatic. All patients underwent preoperative duplex ultrasound examinations. All patients undergoing CAS had the presence of ICA stenosis confirmed by angiography during the CAS procedure. Patients undergoing CEA had preoperative angiography or CT angiography. Patients with recurrent ICA stenosis, previous cervical radiation therapy, tracheostomy, or ICA stenosis above the C2 level were excluded from the study.
Of 301 patients who had CAS with cerebral protection, 301 were matched with control patients who had CEA during the same period (2001-2004). Matching was by sex, age, symptoms, and coronary artery disease.
Outcome measures were stroke, death, cardiac events, and local complications. Intraprocedure CAS complications were divided into 3 phases:
1) During the passage of the aortic arch and cannulation of the ICA;
2) The crossing of the lesion phase including placement of the cerebral protection device (CPD); and
3) The stent-ballooning procedure including recovery of the CPD.
There was no evidence of a statistically significant increase in the risk of disabling stroke and death in CAS patients compared with CEA controls (see Table 1). The risk of any stroke, however, favored CEA over CAS. Eight disabling strokes (2 fatal) occurred in the CAS group. Four were due to massive embolization during phase one. The remaining 4 strokes occurred during phase 3. Of 16 nondisabling strokes in CAS patients, one occurred during phase one, one during phase 3, 10 within the first 24 hours after CAS, and 4 after 24 hours. The majority of TIAs (18/19) occurred during phase 3 of CAS. Bradycardia or hypotension occurred during the procedure in 34% of CAS patients, despite the use of atropine.
At a mean follow-up of 18 months (range, 3-48 months), there was no significant difference in the rate of restenoses in the CAS group (n = 4, 1.3%) vs the CEA group (n = 10, 3.3%).
Although the study is a retrospective analysis of a nonrandomized population, Cao et al's observations provide useful insights into the intraprocedural stroke risk for patients undergoing CAS. Notable, too, was the presence of a learning curve for technical expertise in performing CAS. The first 100 CAS patients had a higher stroke rate than later CAS patients. Therefore, if the first 100 CAS patients are excluded from outcome analysis, then the last 201 CAS patients did not have a stroke risk significantly different from the corresponding 201 CEA-matched controls.
At present, it is not possible to exclude a difference favoring one treatment over the other. Nevertheless, given the appropriate technical expertise and experience, an interventionalist performing CAS can expect outcomes identical to those achieved by the surgeon performing CEA.
1. Endovascular versus Surgical Treatment in Patients with Carotid Stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): A Randomised Trial. Lancet. 2001;357:1729-1737.