ABSTRACT
Paclitaxel is a new cancer chemotherapeutic agent that has been approved for clinical use in patients with a variety of different cancers. Paclitaxel inhibits cell proliferation by an action on microtubules. The aim of this study was to evaluate the safety and efficacy of locally delivered paclitaxel after coronary stent implantation. A novel double-balloon perfusion catheter was used to deliver the drug locally in the pig coronary artery. Twenty-seven domestic pigs underwent stent implantation of the left anterior descending artery. In the treatment group (n = 11), paclitaxel (10 ml; 10 micromol/l) was delivered using the double-balloon perfusion catheter prior to stent implantation. The control group received stent implantation only (n = 16). The animals were sacrificed 4 weeks later. Vessels were perfusion-fixed and morphometric analysis was performed using conventional techniques. In addition, the extent of injury was determined at each stent-strut area. Correlation of local injury and neointimal thickness was evaluated by linear regression. Neointimal thickness (paclitaxel 1.0 +/- 0.4 vs. control 0.7 +/- 0.3 mm), neointimal area (paclitaxel 4.1 +/- 2.2 vs. control 2.4 +/- 1.1 mm(2)), and the lumen area (paclitaxel 2.1 +/- 1.9 vs. control 2.5 +/- 0.9 mm(2)) did not show significant differences between both groups. Medial area (3.3 +/- 2.3 vs. 1.6 +/- 0.4 mm(2)) was larger in the vessels treated with paclitaxel (P < 0.05). Linear regression failed to show any difference in the response to injury between the two groups. Local delivery of paclitaxel with the double-balloon-perfusion catheter did not reduce neointima formation following stent implantation in native pig coronary arteries.
