Response by Mitomo et al to Letter Regarding Article, “Bioresorbable Vascular Scaffolds for the Treatment of Chronic Total Occlusions: An International Multicenter Registry”

In Response:We appreciate the interest and comments of Muntané-Carol et al for our article regarding the feasibility and safety of bioresorbable vascular scaffold (Absorb BVS; Abbott Vascular, Santa Clara, CA) implantation in chronic total occlusions. 1 As reported, malapposed BVS struts are associated with high thrombogenicity and poor endothelization.Underexpanded BVS struts cause flow disturbance with low shear stress.These factors can increase the risk of restenosis and scaffold thrombosis. 2 For these reasons, we performed optimal lesion preparation and postdilatation with intravascular guidance in all cases of our registry to lower the risk of target lesion failure and scaffold thrombosis during the study period (median, 453 days).We should consider that chronic total occlusion lesions generally require implantation of long stents; therefore, BVS are a reasonable alternative to metallic stents, avoiding a permanent cage facilitating additional treatments.As the authors mentioned, if the struts are appropriately embedded at the index procedure, BVS could accommodate future positive remodeling of the vessel.Despite these potential advantages, the decision of BVS implantation for chronic total occlusion needs careful evaluation.Vessel sizing, lesion morphology, and TIMI (Thrombolysis In Myocardial Infarction) flow grade after recanalization are the most important factors to be taken into account to achieve the best possible results.Furthermore, BVS implantation in subintimal space should be taken into account because bioresorption or endothelization have not been sufficiently studied yet.Therefore, we would recommend longer dual antiplatelet therapy after BVS implantation for chronic total occlusion lesion if the patients can tolerate the therapy.Discontinuation of dual antiplatelet therapy has been associated with scaffold thrombosis. 3For all these reasons, operators need to select the suitable patient and lesion for BVS implantation.