Attainment of local drug delivery with paclitaxel-eluting balloon in porcine coronary arteries

Objective Our purpose was to confirm the local drug delivery of a paclitaxel-eluting balloon by percutaneous intervention of single arterial segments or bifurcations of porcine coronary arteries. Methods Eight domestic pigs were subjected to 2×30 s Dior balloon dilatation of the mid left anterior descending, left circumflex and proximal right coronary arteries. Bifurcation intervention was performed in six arteries. The dilated, and the distal and proximal reference segments were prepared for tissue paclitaxel concentration measurement. Tissue samples were harvested at mean 1.5, 12, 24 and 48 h after balloon dilatation and plasma samples were taken at various time points. Results The tissue paclitaxel concentration of the single dilated segment was at 1.5 h postdilatation 1.82±1.60 μmol/l, which decreased significantly to 0.73±0.27 (P=0.032), 0.62±0.34 and 0.44±0.31 μmol/l at 12, 24 and 48 h. The bifurcation intervention resulted in 5.10±1.80 μmol/l tissue paclitaxel amount in the main branch, which at 12 h had diminished to 1.41±1.23 μmol/l (P=0.004). The bifurcation side contained 7.00±4.80 μmol/l paclitaxel at 1.5 h postdilatation, which lowered to 2.72±0.40 μmol/l (P=0.034). The mean paclitaxel concentration of the reference segments decreased gradually from 0.84±0.99 to 0.34±0.36 μmol/l (P=0.09), 0.28±0.16 and 0.19±0.18 μmol/l tissue at 1.5, 12, 24 and 48 h postdilatation, respectively. No paclitaxel was found in the peripheral blood at any time point. Conclusion Short exposure of the coronary artery to paclitaxel with a coated balloon is sufficient for the attainment of an adequate tissue concentration of paclitaxel, which is known to be efficient in inhibiting neointimal growth.