894 The Effects of Shockwave Lithotripsy on Drug-Eluting Stents

Abstract

Case series describing use of Shockwave lithotripsy within under-expanded stents are becoming more common in the medical literature. To use electron microscopy (EM) to assess the physical effects of shockwave lithotripsy on the structure of various types of polymer-free and polymer-coated drug-eluting stents. The following stents were deployed ex-vivo to 3mm and baseline EM scans were performed: polymer-free 3mm Cre8; bioabsorbable polymer 3mm Synergy; durable polymer 3mm Resolute Integrity and durable polymer 3mm Xience Alpine. A 3mm Shockwave C2 catheter was inflated to 4atm, and used to deliver 20, 50 and 80 pulses within the stents in a water bath at body temperature. Stent disruption was quantified based on a stent architectural deformation assessment (ADA) grade, which is defined as follows: Grade 0 - no damage; Grade I – presence of cracking, pitting or blister formation with no peeling of polymer or drug; Grade II – presence of partial thickness peeling of polymer or drug; Grade III – presence of full-thickness peeling of polymer with visible underlying metal surface; Grade IV – visible disruption to the metal architecture of the stent. Tabled 1PulsesSynergyResolute IntegrityXience AlpineCre820000050III0080IIIIIII0 Open table in a new tab Lithotripsy pulses lead to disruption of polymer integrity. The polymer-free Cre8 stent appeared to be less susceptible to the damaging effects of lithotripsy. Finally, 20 pulses of lithotripsy did not cause perceptible disruption to the surface architecture of any of the stents tested in this study.