Cavitation catheter

Patent metadata

Field	Value
Publication number	US-10543007-B2
Application number	US-201715475203-A
Country	US
Kind code	B2
Filing date	Mar 31, 2017
Priority date	Mar 31, 2017
Publication date	Jan 28, 2020
Grant date	Jan 28, 2020

Abstract

In some examples, a catheter includes an elongated body configured for navigation through vasculature of a patient, the elongated body having an inner wall that defines a lumen extending from a proximal portion to a distal portion. The elongated body is configured to pass a fluid through the lumen and out a distal end of the elongated body. At the distal portion, the inner wall defines a convergent-divergent region such that a diameter of the lumen while moving distally within the elongated body converges from a first lumen diameter to a second lumen diameter and then diverges from the second lumen diameter to a third lumen diameter. The convergent-divergent region is configured to cause a fluid flowing through the lumen to cavitate as the fluid flows through the convergent-divergent region.

First claim

What is claimed is:

1. A catheter comprising:
an elongated body configured for navigation through vasculature of a patient, the elongated body comprising an inner wall that defines a lumen extending from a proximal portion to a distal portion, the elongated body configured to pass a fluid through the lumen and out an ejection port at a distalmost end of the catheter,
wherein at the distal portion of the elongated body, the inner wall defines a convergent-divergent region such that a diameter of the lumen while moving distally within the elongated body converges from a first lumen diameter to a second lumen diameter and then diverges from the second lumen diameter to a third lumen diameter, wherein the ejection port at the distalmost end of the catheter has a fourth lumen diameter that is greater than the second lumen diameter, wherein the convergent-divergent region is configured to cause the fluid flowing through the lumen at a target flow rate to cavitate and produce a pressure shockwave as the fluid flows through the convergent-divergent region, wherein the catheter is configured such that the fluid flowing out of the ejection port at the distalmost end of the catheter is unimpeded, and wherein the catheter is configured such that the pressure shockwave emerges from the ejection port at the distalmost end of the catheter.

2. The catheter of claim 1 , wherein the convergent-divergent region comprises a cavitation region defined by the inner wall, the cavitation region having a length of about 0.5 millimeters (mm) to about 3 mm, wherein the length of cavitation region is an axial distance from a point where the second lumen diameter begins to diverge to the third lumen diameter to the distal end of the elongated body.

3. The catheter of claim 2 , wherein the cavitation region comprises at least one radiopaque marker.

4. The catheter of claim 1 , wherein a ratio of the third lumen diameter to the second lumen diameter is at least about 2.5:1.

5. The catheter of claim 1 , wherein the elongated body defines a substantially continuous outer diameter along the convergent-divergent region.

6. The catheter of claim 1 , wherein the elongated body defines an outer diameter along the convergent-divergent region having an hour-glass shape.

7. The catheter of claim 1 , further comprising a balloon connected to the elongated body proximal to the convergent-divergent region.

8. The catheter of claim 1 , wherein the elongated body further comprises a structural support element at the convergent-divergent region, the structural support element comprises at least one of a wire braid or a coil.

9. The catheter of claim 8 , wherein the convergent-divergent region comprises a neck section defined by the second lumen diameter, wherein the structural support element surrounds the inner wall of the convergent-divergent region at the neck section.

10. The catheter of claim 1 , further comprising an outer casing positioned over the inner wall, wherein the outer casing defines a substantially continuous outer diameter of the catheter along the convergent-divergent region.

11. The catheter of claim 10 , wherein the convergent-divergent region comprises a neck section defined by the second lumen diameter, wherein a region between the inner wall at the neck section and the outer casing comprises an elastic or inelastic fill material.

12. The catheter of claim 1 , wherein the elongated body comprises at least one protuberance extending into the lumen within the convergent-divergent region, wherein the at least one protuberance is configured to agitate the flow of the fluid that passes through the lumen.

13. The catheter of claim 12 , wherein the at least one protuberance comprises a ridge, a fin, a divot, a bump, or a ripple in the inner wall.

14. The catheter of claim 1 , wherein the fourth lumen diameter is approximately equal to the third lumen diameter.

15. The catheter of claim 14 , wherein the diameter of the lumen between the third lumen diameter and the ejection port at the distalmost end of the catheter is substantially constant.

16. The catheter of claim 1 , wherein the diameter of the lumen between the third lumen diameter and the ejection port at the distalmost end of the catheter does not converge.

17. The catheter of claim 1 , wherein the convergent-divergent region is configured to cause a velocity of the fluid at a given flow rate to decrease and increase a hydrostatic pressure of the fluid as the fluid transitions within the lumen from a first portion of the lumen having the second lumen diameter to a second portion of the lumen having the third lumen diameter, and wherein the increase in the hydrostatic pressure of the fluid causes gaseous bubbles to implode within the lumen to release energy in the form of the pressure shockwave.

18. The catheter of claim 1 , wherein, when the ejection port if positioned proximate to a calcified lesion, the pressure shockwave is configured to break up at least a part of the calcified lesion.

19. The catheter of claim 1 , further comprising an outer casing positioned over the inner wall, wherein the outer casing does not extend distally beyond a distalmost end of the elongate body.

20. The catheter of claim 1 , wherein the diameter of the lumen, while moving distally within the elongated body, converges from the first lumen diameter to the second lumen diameter non-linearly.

21. The catheter of claim 1 , wherein the catheter is configured such that the pressure shockwave emerges from the ejection port at the distalmost end of the catheter to impact a lesion adjacent the ejection port.

22. An assembly comprising:
a catheter comprising an outer casing and an elongated body configured for navigation through vasculature of a patient, the elongated body comprising an inner wall that defines a lumen extending from a proximal portion to a distal portion, the elongated body configured to pass a fluid through the lumen and out an ejection port at a distalmost end of the catheter, wherein at the distal portion of the elongated body, the inner wall defines a convergent-divergent region such that a diameter of the lumen while moving distally within the elongated body converges from a first lumen diameter to a second lumen diameter and then diverges from the second lumen diameter to a third lumen diameter, wherein the ejection port at the distalmost end of the catheter has a fourth lumen diameter that is greater than the second lumen diameter, wherein outer casing positioned over the inner wall, and wherein the outer casing does not extend distally beyond a distalmost end of the elongate body; and
a pump assembly connected to the proximal portion of the elongated body of the catheter and configured to pump a fluid at a target flow rate through the lumen of the elongated body and out the ejection port, wherein the convergent-divergent region of the elongated body is configured to cause the fluid flowing through the lumen at the target flow rate to cavitate and produce a pressure shockwave as the fluid flows through the convergent-divergent region, and wherein the catheter is configured such that the pressure shockwave emerges from the ejection port at the distalmost end of the catheter.

23. The assembly of claim 22 , further comprising the fluid, wherein the fluid comprises saline.

24. The assembly of claim 22 , the convergent-divergent region of the elongated body is configured to cause the fluid flowing at the target flow rate of about 1 cub

Assignees

• Medtronic Vascular Inc

Inventors

• Donegan Michael

Classifications

• A61B2017/22065

  Functions of balloons · CPC title

• A61M2025/0073

  Tip designed for influencing the flow or the flow velocity of the fluid, e.g. inserts for twisted or vortex flow · CPC title

• A61M25/0045

  multi-layered, e.g. coated (coating materials A61L29/08) · CPC title

• A61M25/0032

  characterized by at least one unconventionally shaped lumen, e.g. polygons, ellipsoids, wedges or shapes comprising concave and convex parts · CPC title

• A61B2017/22025

  applying a shock wave (A61B2017/22091 takes precedence) · CPC title