Drug delivery shock wave balloon catheter system
A catheter comprises an elongated carrier and a balloon carried by the carrier in sealed relation thereto. The balloon has an outer surface and is arranged to receive a fluid therein that inflates the balloon. The catheter further comprises a shock wave generator within the balloon that forms mechanical shock waves within the balloon, and a medicinal agent carried on the outer surface of the balloon. The medicinal agent is releasable from the balloon either before or in response to the shock wave.
1. A method for treating calcified lesions in a blood vessel comprising:
providing a catheter having an elongated carrier, a balloon carried by the elongated carrier in sealed relation thereto, a shock wave generator within the balloon, and a medicinal agent applied to the outer surface of the balloon in a manner such that the medicinal agent is at least partially released when the balloon is inflated into contact with the wall of a blood vessel;
inserting the catheter into a blood vessel to be treated;
inflating the balloon with a liquid to a pressure sufficient to create contact between the outer surface of the balloon and the wall of the blood vessel causing the release of a portion of the medicinal agent from the balloon without the generation of shock waves;
generating a shock wave within the balloon to crack calcified lesions in the blood vessel with the balloon remaining sealed both during and after the creation of the shock wave; and
after the generating step, further inflating the balloon with the liquid to further release the medicinal agent.
2. The method of claim 1 , wherein during the initial inflating step, the balloon is pressurized to between 1 and 4 atmospheres.
3. The method of claim 1 wherein the shock wave is generated by supplying a high voltage pulse to a pair of electrodes located within the balloon to produce a plasma arc which in turn creates a mechanical shock wave within the balloon.
4. The method of claim 1 wherein the medicinal agent is in the form of a drug coated on the outer surface of the balloon wall.
5. The method of claim 1 wherein the medicinal agent is coated on the outer surface of the balloon with an excipient.
6. The method of claim 1 , wherein the medicinal agent is contained within a plurality of microspheres.
7. The method of claim 1 , wherein the medicinal agent is a drug contained within a plurality of microcapsules, wherein the drug is releasable from the plurality of microcapsules in response to the shock wave.