Abraham Tzafriri, Benny Muraj, Fernando Gacia-Polite, Antonio-Gabino Salazar-Martin, Peter Markham, Anna-Maria Spognardi, Brett Zani, Mazen Albaghdadi, Steve Alston, and Elazer Edelman. Drug-Coated Balloon Contact Pressure Predicts Endoluminal Coating Distribution.
Background: Paclitaxel-coated balloons (PCBs) control iliofemoral atherosclerotic lesions, yet restenosis rates remain high without class effect. We leveraged novel imaging and computational modeling to add insight into the micromorphology dependence of coating transfer and optimize device efficacy.
Methods: We compared PCBs coated with amorphous/flaky (n = 4) or microneedle coatings (n = 8) inflated for 60 s in porcine femoral arteries. Animals were sacrificed at 0.5 h. Coating delivery was quantified by scanning electron microscopy and paclitaxel levels by mass spectrometry. A coupled computational angioplasty tissue microindentation model (Figure A,B insets) predicted micromorphology-dependent contact pressures at the tissue interface (Figure C,D).
Results: PCBs deposit variable drug commensurate with differences in coating delivery as sparse endoluminal patches (Figure A,B). Flaky coated balloons only coated 10.4% of the endolumen, whereas microneedles coated 1.5-fold greater area (16.1%, p = 0.0035), consistent with 1.5-fold higher tissue deposition (1,298 vs. 1,933 μg/g, p = 0.1745). Longitudinal coating gradients by scanning electron microscopy (Figure E,F) tightly tracked (r = 0.9, p < 0.001) predicted contact pressure gradients by the microneedle (Figure C) and flaky coatings (Figure D).
Conclusion: PCBs deposit drug coating onto a small fraction of the endoluminal surface, with microcrystalline coatings conferring an advantage because of amplification of the angioplasty pressure. Tracking of coating deposition with coating−tissue contact pressure can provide new insights not only into coating optimization but also the dependence on procedural parameters and lesion stiffness.