Randomized trial of predilation versus direct stenting for treatment of carotid artery stenosis

Abstract

Background

A controversial aspect of carotid artery stenting (CAS) is the placement of a stent with or without predilation. The study was designed to test the hypothesis that direct stenting (DS) was not inferior to CAS with predilation.

Methods

Elective CAS with filter protection was performed in 205 consecutive, unselected patients with carotid artery stenosis (> 50% if symptomatic and ≥ 75% if asymptomatic by Doppler assessment) who were randomly assigned to CAS with predilation (n = 100) or direct stenting (DS, n = 105). Filter and stent selection were left to the operator's discretion. The study end-point was the angiographic success, defined as ≤ 30% angiographic residual stenosis after CAS without abnormal angiographic findings in cerebral circulation and without cross-over to predilation in the DS group.

Results

At baseline, patient clinical characteristics and stenosis anatomic features did not differ between groups. Angiographic success was 99% and 97%, p = 0.33, in predilation and DS, respectively. No cross-over to predilation occurred in the DS group. Procedural time was shorter in DS as compared to predilation (24.3 ± 7% versus 19.9 ± 6%, p = 0.001) and visible debris were more frequently captured in predilation as compared to DS (50% versus 36%, p = 0.003). No peri-procedural and 30-day death or major stroke occurred in both groups. Minor stroke and TIA rates were similar in either group (2% versus 0% and 8% versus 5.7%, p = ns, respectively).

Conclusion

In an unselected, consecutive series of patients submitted to CAS, DS is a feasible technique and is not inferior to CAS with predilation.

Introduction

Carotid artery stenting (CAS) is gaining scientific support as an alternative treatment to carotid endarterectomy for the prevention of stroke caused by extra-cranial carotid artery stenosis. Standard endovascular procedure includes distal embolic protection device positioning first, followed by lesion predilation, stent deployment and overexpansion and, finally, embolic protection device retrieval [1], [2]. While most of CAS steps are well established, the role of systematic predilation is still a matter of debate. Overall, the frequency of predilation has been reported to range between 30% and 70% [1], [2], [3], [4], [5]. In clinical practice, predilation is usually preferred in sub-occlusive and/or severely calcified vessels. In these anatomical settings, the larger lumen induced by predilation may facilitate stent crossing and positioning as well as uniform stent deployment and expansion.

Direct stenting (DS) is the alternative to lesion predilation. The rationale of DS in CAS is to achieve early plaque debris entrapment between the stent struts and the arterial wall, reducing the risk of cerebral embolization. Additional advantages may include a reduced amount of contrast medium injected into the cerebral circulation, less artery wall injury that may translate in reduced neointimal hyperplasia and in-stent restenosis rate, lower cost and shorter fluoroscopy and procedural time.

However, no scientific evidence has been produced supporting the superiority (i.e. feasibility, safety and efficacy) of one technique over the other in CAS. Thus, this randomized trial was primarily designed to assess the feasibility of DS as compared to predilation in a consecutive series of patients submitted to CAS for treatment of significant extra-cranial carotid artery stenosis.