Neointima reduction with IVUS and rapamycin microbubbles: In Vivo swine model results

An intravascular ultrasound (IVUS) catheter, optimized for microbubble-enhanced drug delivery, was used to reduce neointima formation in a swine model of balloon injury. In order to minimize neointima formation following balloon injury, rapamycin-loaded microbubbles were infused into the region of injury. During microbubble infusion, arteries were treated with, or without, IVUS catheter insonation. Twenty eight days after treatment, injured arteries were excised, sectioned, and imaged. A reduction in neointima formation of 65% was measured in arteries treated with IVUS and rapamycin-loaded microbubbles as compared to arteries treated with rapamycin-loaded microbubbles alone (no ultrasound). These results indicate that IVUS, paired with drug-loaded microbubbles, may be a viable approach for achieving localized delivery of intravascular antiproliferative therapies.