Apparatus and methods for dilating vasospasm of small intracranial arteries

• US 20050059938A1
• Filed: 09/15/2004
• Published: 03/17/2005
• Est. Priority Date: 09/16/2003
• Status: Active Grant

• Current Assignee: Board of Trustees of The University of Illinois
• Original Assignee: Board of Trustees of The University of Illinois
• Inventors: Malisch, Timothy Wayne
• Granted Patent: US 7,651,488 B2
• Time in Patent Office: Days
• US Class Current: 604/265
• CPC Class Codes: A61M 2025/0042 Microcatheters, cannula or the like having outside diameters around 1 mm or less
• CPC Class Codes: A61M 2025/0046 Coatings for improving slidability
• CPC Class Codes: A61M 2025/0057 Catheters delivering medicament other than through a conventional lumen, e.g. porous walls or hydrogel coatings
• CPC Class Codes: A61M 25/0023 by the form of the lumen, e.g. cross-section, variable diameter
• CPC Class Codes: A61M 25/0068 Static characteristics of the catheter tip, e.g. shape, atraumatic tip, curved tip or tip structure
• CPC Class Codes: A61M 25/0074 Dynamic characteristics of the catheter tip, e.g. openable, closable, expandable or deformable
• CPC Class Codes: A61M 25/008 Strength or flexibility characteristics of the catheter tip
• CPC Class Codes: A61M 25/0082 Catheter tip comprising a tool
• CPC Class Codes: A61M 25/104 used for angioplasty
• CPC Class Codes: A61M 29/00 Dilators with or without means for introducing media, e.g. remedies instruments for performing visual medical inspections of cavities or tubes of the body A61B1/00

Abstract

A device and method for treatment of intracranial vasospasm is provided. The device is a microcatheter having a steeply tapered end and is thicker walled, and in a preferred embodiment is braided to provide greater pushability. In order to achieve a thicker walled catheter, in one embodiment, the inner lumen diameter can be reduced, leaving the outer diameter the same while in another embodiment the catheter is larger in outer diameter. In one embodiment, the microcatheter is coated with performance enhancing lubricant, such as a hydrophilic coating. Further, the microcatheter can also be coated with drugs and serve as a drug delivery device, drugs being embedded into vessel intima. In the use of the method of treatment, the device is fed into the smaller arterial vessels in the brain simultaneously dilating arteries of various caliber along the path of the catheter to relieve vasospasm; pharmacological agents can then be delivered by the microcatheter to further effect treatment.

Claims

1. A microcatheter for dilating vasospasm of small intracranial arteries in a skull comprising:

an elongated, steeply tapered, flexible element, the element having a length and an outer diameter sufficiently small and the element being sufficiently flexible to permit insertion into a larger artery at a base of the skull and directing the microcatheter into distal first, second and third order branches for simultaneous dilatation and improvement in caliber of at least two of the branches.

2. The microcatheter in accordance with claim 1 wherein the microcatheter is formed having an internal lumen having an internal diameter and defining a wall thickness.

3. The microcatheter in accordance with claim 2 wherein the internal diameter remains substantially constant along the length of the microcatheter.

4. The microcatheter in accordance with claim 1 wherein the microcatheter is formed as a braided element.

5. The microcatheter in accordance with claim 1 wherein the catheter has a coating thereon.

6. The microcatheter in accordance with claim 5 wherein the coating is a lubricant.

7. The microcatheter in accordance with claim 6 wherein the coating is a pharmacological agent.

8. The microcatheter in accordance with claim 7 wherein the pharmacological agent is an anticoagulant, an anti-platelet or a vasoactive agent.

9. The microcatheter in accordance with claim 1 wherein the length of the microcatheter is about 120 cm to about 150 cm.

10. The microcatheter in accordance with claim 9 wherein the length is about 120 cm.

11. The microcatheter in accordance with claim 2 wherein the diameter of the lumen is about 14 mils to about 22 mils.

12. The microcatheter in accordance with claim 9 including a lead wire and wherein the lead wire has a diameter of about 10 mils to about 18 mils.

13. The microcatheter in accordance with claim 9 wherein the taper occurs at about the distal most 20 cm to 30 cm of the flexible element.

14. The microcatheter in accordance with claim 13 wherein the taper is from an initial diameter of about 3 mm to a tapered end diameter of less than about 1 mm.

15. The microcatheter in accordance with claim 14 wherein the tapered end diameter is about 0.67 mm.

17. The method in accordance with claim 15 including the step of administering a pharmacological agent to the larger artery, the first, second or third order arteries.

19. The method in accordance with claim 15 including the step of introducing a lead wire to the first, second, or third order artery and moving the microcatheter along the lead wire to introduce the microcatheter to the first, second, or third order arteries.

16. A method for dilating vasospasm of intracranial arteries comprising the steps of:

introducing a microcatheter having an elongated steeply tapered, flexible element, the element having a length and an outer surface defining an outer diameter into a larger artery at a base of a skull;

manipulating the microcatheter through the larger artery;

directing the microcatheter toward distal first, second and third order branches;

urging the microcatheter toward the distal first, second and third order branches; and

dilating and improving caliber simultaneously of at least two of the branches.

18. The method in accordance with claim 16 wherein the pharmacological agent is administered by contact of the microcatheter with the larger artery, first, second or third order arteries.