Methods, systems, and kits for plaque stabilization

• US 20020032394A1
• Filed: 03/07/2001
• Published: 03/14/2002
• Est. Priority Date: 03/08/2000
• Status: Abandoned Application

• Current Assignee: PharmaSonics, Inc.
• Original Assignee: PharmaSonics, Inc.
• Inventors: Zuk, Robert, Brisken, Axel, Moore, Paulina
• Application Number:
  US09/801,571
• Publication Number:
  US 20020032394A1
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 17/2202 the ultrasound transducer being inside patient's body at the distal end of the catheter
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61B 2017/22001 Angioplasty, e.g. PCTA
• CPC Class Codes: A61B 2017/22054 with two balloons
• CPC Class Codes: A61B 2017/22062 to be filled with liquid
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

Atherosclerotic plaque and blood vessels may be stabilized by directing vibrational energy, typically ultrasonic energy, into the adjacent blood vessel wall. Application of the vibrational energy, optionally in combination with growth factors, growth factor genes, or other substances which enhance growth instability of a fibrotic cap over the plaque, will reduce the risk of rupture of unstable plaque and inhibit the conversion of stable plaque into unstable plaque.

Claims

1. A method for promoting endothelial integrity in blood vessels, said method comprising:

exposing a target region within the blood vessel of a patient to vibrational energy at a mechanical index and for a time sufficient to promote endothelial restoration within the target region.

2. A method as in claim 1, further comprising selecting a patient having a blood vessel target region characterized by unstable plaque.

3. A method as in claim 1, further comprising selecting a patient having a blood vessel target region characterized by stable plaque.

4. A method as in claim 2 or 3, further comprising imaging the blood vessel to determine the nature of plaque within the blood vessel.

5. A method as in claim 1, wherein the patient is treated with the vibrational energy prior to plaque rupture.

6. A method as in claim 1, wherein exposing the blood vessel comprises:

positioning an interface surface on or coupled to a vibrational transducer within the blood vessel at the target site; and

driving the transducer to direct vibration energy from the interface surface against the blood vessel wall.

7. A method as in claim 1, wherein exposing the blood vessel comprises:

positioning an interface surface on or coupled to a vibrational transducer against a tissue surface over the target region of the blood vessel; and

driving the transducer to direct vibrational energy from the interface surface against the blood vessel wall.

8. A method as in claim 7, further comprising positioning the interface surface to direct the vibrational energy toward a beacon signal located at the target region within the blood vessel.

9. A method as in claim 1, wherein exposing the blood vessel comprises:

positioning an interface surface on or coupled to a vibrational transducer within a second blood vessel located near the target region of the target blood vessel; and

driving the transducer to direct vibrational energy from the interface surface through tissue between the second blood vessel and the target blood vessel to the target region within the target blood vessel.

10. A method as in claim 1, wherein exposing the blood vessel comprises:

positioning an interface surface coupled on or to a vibrational transducer within a heart chamber, wherein the target blood vessel is a coronary artery positioned over the heart chamber;

driving the transducer to direct vibrational energy outwardly from the heart chamber, through the myocardium, and into the coronary artery.

11. A method as in claim 1, wherein exposing the blood vessel comprises:

surgically opening tissue overlying the target blood vessel;

positioning an interface surface on or coupled to a vibrational transducer over the exposed target blood vessel; and

driving the transducer to direct vibrational energy into the target region of the exposed target vessel.

12. A method as in claim 1, further comprising administering to the target region an amount of biologically active substance (bas) sufficient to promote endothelial restoration within the target region.

13. A method as in claim 12, wherein the bas is administered at least prior to exposing the target region to vibrational energy.

14. A method as in claim 12, wherein the bas is administered at least during exposure of the target region to vibrational energy.

15. A method as in claim 12, wherein the bas is administered at least after exposure of the target region to vibrational energy.

16. A method as in claim 12, wherein the bas is selected from the group consisting of growth factors, growth factor genes, tissue inhibitor metalloproteinase (TIMP), and TIMP gene.

17. A method as in any of claims 1-16, wherein the vibrational energy comprises compression waves which travel to the arterial wall in substantially radial direction.

18. A method as in any of claims 1-16, wherein the vibrational energy does not cause significant cavitation in a wall of the artery.

19. A method as in any of claims 1-16, wherein the vibrational energy causes a temperature rise below 10°

C. in the wall of the artery.

20. A method as in any of claims 1-16, wherein the vibrational energy has a frequency in the range from 100 kHz to 5 MHz.

21. A method as in claim 20, wherein the intensity is in the range from 0.01 W/cm² to 100 W/cm².

22. A method as in claim 21, wherein the frequency and intensity are selected to produce a mechanical index at the neointimal wall in the range from 0.1 to 50.

23. A method as in any of claims 1-16, wherein the vibrational energy is directed against the arterial wall with a pulse repetition frequency (PRF) in the range from 10 Hz to 10 kHz.

24. A method as in any of claims 1-16, wherein the energy is directed against the arterial wall with a duty cycle in the range from 0.1 to 100 percent.

25. A kit comprising:

a catheter having an interface surface; and

instructions for use according to any of claims 1-6, 9, 10, and 12-16.

26. A kit comprising:

an external vibrational source having an interface surface; and

instructions for use according to any of claims 1-5, 8, and 11-16.