In a recent presentation at the EVES meeting in Prague, Dr Marc Bosiers, AZ St-Blasius in Dendermonde, Belgium, discussed whether the characteristics of a device affects outcomes in carotid artery stenting. He began by stating that carotid endarterectomy is effective as the procedure removes the plaque from the body (‘garbage removal’) thereby removing the embolisation risk, where as carotid stenting is about plaque containment (‘garbage compactor’). However, he added that not all stents contain the same characteristics (closed cell/open cell) and therefore hypothesised that their ability (performance) to contain plaque could be different.
As a result, he presented data from the Belgian Italian Carotid (BIC) study, a carotid artery stenting database consisting of 3,179 consecutive patients from four ‘highly-experienced’ European centres. The distribution of neurological complications were analysed for association with the different stent types and designs and vents were subdivided into procedural and postprocedural events (30-day rates for stroke, death and TIA).
Stenting with an embolic protection device (EPD) was performed in 3,049 patients (95.9%): distal filtrations systems were used in 2,831 (92.9%) cases (FilterWire – Boston Scientific, Angioguard – Cordis, Accunet – Guidant, Emboshield – Abbott Vascular, Rubicon Filter – Rubicon Medical, Spider – ev3, Trap – ev3, Interceptor – Medtronic), proximal occlusion in 192 (6.4%) cases (Mo.Ma – Invatec, Parodi Anti Emboli System – Gore) and distal occlusion in 26 (0.8%) cases (Percusurge – Medtronic) patients. In addition, closed cell stents (all stent-struts are interconnected: Carotid Wallstent – Boston Scientific; X-act – Abbott Vascular Devices; NexStent – Endotex) were used in 2,242 (70.5%) cases and open cell stent (Precise – Cordis; Exponent – Medtronic Vascular; Protege – ev3; Acculink – Guidant) implantation was performed in 937 (29.5%) procedures.
The overall combined rate of TIA, stroke and death was 2.8% at 30 days (late events 1.9%) and the post-procedural event rate analysed for differences stents varied from 1.2% (Wallstent) to 5.9% (Exponent). The results showed that by comparing stents by cell types (open vs. closed) there was, in the in the symptomatic patient population, a 3.9 times lower risk of post-procedural events for the closed cell group.
Bosiers concluded that after carotid stenting, complication rates vary according to stent type, free cell area and cell design. In the symptomatic population (and also in the total population), post-procedural complication rates are highest for the open cell. He recommended that prospective randomised trials are required to further investigate the importance of free cell area. In the meantime, stents with a small free cell area should be used in symptomatic patients.
The study has been accepted for publication in the European Journal of Vascular and Endovascular Surgery.