Background: Local drug delivery at angioplasty treatment sites may improve acute and long-term results after angioplasty. A new dual-purpose balloon angioplasty catheter containing intramural channels and exterior pores ('channeled balloon') was designed to allow local drug delivery at low pressure without jet streams during simultaneous balloon angioplasty.
Methods: Acute feasibility studies were performed in normal ex-vivo and in-vivo arteries (three canine arteries and three rabbits with normal iliac arteries), in which 2 ml of marker agents were locally infused at 2 atm during simultaneous angioplasty at 6 atm with the channeled balloon. Histology, radioactive counting, and autoradiography were performed to determine the intramural localization of the delivered markers. The in-vitro efficiency of acute local drug delivery was estimated in seven normal canine arteries by infusing 3H-heparin and radioactive counting.
Results: Histology revealed the presence of markers in the inner third of the media in all ex-vivo samples, and markers in all in-vivo iliac arteries except for one, whereas control segments had no intramural staining. Autoradiography documented transmural radioactive granules. Radioactive counts were 40- to 263-fold higher in those locally treated with the radioactive marker agent. Efficiency of the acute local delivery was estimated by dividing the actual counts by the expected counts; it ranged from 24 to 48%.
Conclusion: This study demonstrates that the channeled balloon is capable of delivering drugs locally at low pressure in adequate concentrations during simultaneous high-pressure balloon angioplasty in normal arteries.