Calcific lesions present another anatomic challenge with minimally invasive treatment of many vascular beds especially the carotid territory. The appropriate stent for this lesion must have high radial strength to resist the radial crush and elastic recoil of the calcified carotid vessel.
Nitinol stents are preferred in the presence of calcification because of there increased radial force relative to stainless steel designs. The closed cell design of the X-Act stent provides high radial force compared to other open cell designs and the closed cell design has the theoretical benefit of minimizing the risk of embolization from the calcified plaque by trapping plaque against the blood vessel wall
The ultimate goal of CAS is the prevention of atheroembolism. The peak time period for athero embolism is in the post deployment period. Closed Cell designs offer the theoretic benefit of decreasing the opportunity for atheroma to squeeze between the interstices of the stent.
Stents with a closed-cell design (Carotid Wallstent, NexStent, X-Act) offer the best theoretic embolic protection under circumstances of the calcified lesion
In my opinion, stent design will not have a signifcant impact for the majorit of cases, however 15-20% of cerebrovascular anatomy will pose an anatomic challenge that may be best addressed by careful stent selection based on these known and accepted stent characteristics.
This again underscores the need for precise imaging and interpretation as the primary factor driving the choice of therapeutic intervention
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