DES surface changes during balloon expansion reported in Journal of American Medical Association research letter
Published date : 05 June 2012
Article date : 05 June 2012
In a research letter published in the May 23/30, 2012 issue of the Journal of the American Medical Association (JAMA), it has been hypothesised that the polymer surface of drug-eluting stents (DES) may become damaged during delivery balloon expansion, and that microparticles may detach. DES surface damage ranging from deformation (ridging, cracking, peeling, or webbing) to complete delamination could lead to potential DES-associated complications, including thrombosis, restenosis, and microvascular and endothelial dysfunction.
In a preliminary study of 4 FDA approved DESs (the Abbott Laboratories Xience V, the Boston Scientific Taxus Liberté, the Cordis Cypher, and Medtronic's Endeavor), a sample of 5 stents from each manufacturer were tested in a vacuum filtration system containing a filtered test medium. A bare metal stent was also used for control purposes. Although each stent was expanded unconstrained, the study was otherwise conducted under conditions mimicking those required for regulatory submission and across the range of conditions required to mirror the variability encountered in clinical practice. Results were pooled across conditions, as no significant differences were noted between the various expansion conditions for each particular DES.
Results of this preliminary study reveal that the median proportion of total surface damage occurring during balloon expansion was associated with polymer type and involved both adluminal and abluminal surfaces. The dimensions of damage and of detached microparticles ranged from 2 to 350 μm. and the extent of damage differed by manufacturer.
The study concludes that further research would be useful to confirm these findings and to further investigate the physiological and clinical consequences of polymer damage and microparticle detachment.
For a full account of this study, read the JAMA research letter 'Changes to Polymer Surface of Drug-Eluting Stents During Balloon Expansion' by J Scott et al.
