Abstract
Aims: The safety and efficacy of drug-coated balloon angioplasty (DCBA), compared to plain old balloon angioplasty (POBA) for peripheral artery in-stent restenosis (ISR), have been examined in clinical trials. However, little is known about the pathological response after DCBA for ISR. We compared the intravascular imaging findings and tissue responses of in-stent neointima in iliac arteries after DCBA and POBA using atherosclerotic porcine peripheral arteries.
Methods: Bare metal stents (BMSs) were implanted in the iliac arteries of microminipigs fed high-cholesterol chow. Four weeks after BMS implantation, stented regions were assessed by optical coherence tomography (OCT), followed by either DCBA or POBA. The adherence of the drugs delivered was observed by OCT and angioscopy, performed immediately after DCBA, and then confirmed with scanning electron microscopy. Four weeks after balloon angioplasty, the stented regions were investigated by OCT followed by pathological examination.
Results: Neointimal volume after DCBA was significantly reduced, while that after POBA showed minimal change. Histological assessments revealed decreases in cell number and the α-smooth muscle actin (SMA)-positive area, while the aniline blue-positive area and the alcian blue-positive area in the neointima was increased, after DCBA as compared to after POBA.
Conclusions: The neointima after DCBA in the BMS-implanted region showed fewer smooth muscle cells and more mature extracellular matrix than that after POBA. These results confirmed the clinical benefits of DCBA with ISR for lower extremity arterial disease.
