Methods for embolizing blood vessels

• US 6,335,384 B1
• Filed: 10/10/2000
• Issued: 01/01/2002
• Est. Priority Date: 01/31/1996
• Status: Expired due to Term

• Current Assignee: Micro Therapeutics, Inc. (Medtronic Plc)
• Original Assignee: Micro Therapeutics, Inc. (Medtronic Plc)
• Inventors: Greff, Richard, Perl, John II, Evans, Scott
• Primary Examiner(s): Szekely, Peter
• Application Number:
  US09/680,944
• Time in Patent Office: 448 Days
• Field of Search: 604/49, 604/53, 424/9.1, 424/9.411, 424/9.42, 424/423, 424/649, 523/105, 523/113, 523/222, 524/173, 524/408
• US Class Current: 523/113
• CPC Class Codes: A61L 2300/418 Agents promoting blood coagulation, blood-clotting agents, embolising agents
• CPC Class Codes: A61L 2300/44 Radioisotopes, radionuclides
• CPC Class Codes: A61L 24/001 Use of materials characterised by their function or physical properties
• CPC Class Codes: A61L 24/0015 Medicaments; Biocides
• CPC Class Codes: A61L 24/02 containing inorganic materials
• CPC Class Codes: A61L 24/04 containing macromolecular materials
• CPC Class Codes: A61L 2430/36 for embolization or occlusion, e.g. vaso-occlusive compositions or devices artificial blood vessels A61L27/507
• CPC Class Codes: A61L 31/02 Inorganic materials
• CPC Class Codes: A61P 13/02 of urine or of the urinary tract, e.g. urine acidifiers
• CPC Class Codes: A61P 15/00 Drugs for genital or sexual disorders for disorders of sex hormones A61P5/24; Contraceptives
• CPC Class Codes: A61P 43/00 Drugs for specific purposes, not provided for in groups A61P1/00-A61P41/00
• CPC Class Codes: A61P 9/14 Vasoprotectives; Antihaemorrhoidals; Drugs for varicose therapy; Capillary stabilisers

Abstract

Disclosed are methods useful for treating vascular lesions wherein a non-particulate agent such as a metal coil is introduced into a vascular site (e.g., an aneurysm cavity) in conjunction with an embolizing composition comprising a biocompatible polymer and a biocompatible solvent.

The biocompatible solvent is miscible or soluble in blood and also solubilizes the polymer during delivery. The biocompatible polymer is selected to be soluble in the biocompatible solvent but insoluble in blood. Upon contact with the blood, the biocompatible solvent dissipates from the embolic composition whereupon the biocompatible polymer precipitates. Precipitation of the polymer in the presence of the non-particular agent permits the agent to act as a structural lattice for the growing polymer precipitate.

In another embodiment, the biocompatible polymer composition can be replaced with a biocompatible prepolymer composition containing a biocompatible prepolymer.

Claims

1. A method for embolizing a vascular site in a patient'"'"'s blood vessel which method comprises

(a) introducing, via a catheter, at the vascular site to be embolized a non-particulate agent or a plurality of said agents;

(b) delivering, via a catheter, to said vascular site a polymer composition comprising a biocompatible polymer, dimethyl sulfoxide and a water insoluble contrast agent

wherein said delivery is conducted under conditions wherein a polymer precipitate forms in situ at said vascular site thereby embolizing the blood vessel and further wherein said non-particulate agent acts as a structural lattice for precipitate growth.

2. The method according to claim 1 wherein said water insoluble contrast agent is selected from the group consisting of tantalum, tantalum oxide, tungsten and barium sulfate.

3. A method for embolizing an aneurysm in a mammalian patient which method comprises

(a) introducing, via a catheter, into the aneurysm cavity a metallic coil or a plurality of metallic coils;

(b) delivering, via a catheter, to said cavity a polymer composition comprising ethylene vinyl alcohol copolymer, dimethyl sulfoxide and a water insoluble contrast agent selected from the group consisting of tantalum, tantalum oxide, tungsten and barium sulfate

wherein said delivery is conducted under conditions wherein a polymer precipitate forms in situ in the aneurysm cavity thereby blocking the aneurysm and further wherein said metallic coil acts as a structural lattice for precipitate growth.

4. The method according to claim 3 wherein said water insoluble contrast agent is tantalum.

5. The method according to claim 3 wherein the polymer composition is injected into the aneurysm at a rate of about 0.05 to 0.3 cc/minute.

6. The method according to claim 3 wherein the polymer composition is injected into the aneurysm at a rate of at least 0.6 cc/minute.

7. A method for embolizing a vascular site in a patient'"'"'s blood vessel which method comprises

(a) introducing, via a catheter, at the vascular site to be embolized a non-particulate agent or a plurality of said agents;

and

(b) delivering, via a catheter, to said vascular site a prepolymer composition comprising a biocompatible prepolymer and a water insoluble contrast agent

wherein said delivery is conducted under conditions wherein said prepolymer polymerizes in situ in said vascular site thereby embolizing the blood vessel and further wherein said non-particulate agent acts as a structural lattice for solid polymer formation.

8. The method according to claim 7 wherein said prepolymer composition further comprises a biocompatible solvent.

9. The method according to claim 8 wherein said biocompatible solvent is selected from the group consisting of dimethylsulfoxide, ethanol, and acetone.

10. A method for embolizing a vascular site in a patient'"'"'s blood vessel which method comprises

(a) introducing, via a catheter, at the vascular site to be embolized a non-particulate agent or a plurality of said agents;

(b) delivering, via a catheter, to said vascular site a polymer composition comprising a biocompatible polymer, dimethyl sulfoxide and a water insoluble contrast agent

wherein said delivery is conducted under conditions wherein a polymer precipitate forms in situ at said vascular site thereby embolizing the blood vessel and further wherein said non-particulate agent becomes fixed against a vascular wall thereby anchoring an embolic site.

11. The method according to claim 10 wherein said water insoluble contrast agent is selected from the group consisting of tantalum, tantalum oxide, tungsten and barium sulfate.

12. The method according to claim 10 wherein said non-particulate agent is a metallic coil or a plurality of metallic coils.

13. The method according to claim 12 wherein said metallic coil is a platinum coil.

14. A method for embolizing an aneurysm in a mammalian patient which method comprises

(a) introducing, via a catheter, into the aneurysm cavity a metallic coil or a plurality of metallic coils;

(b) delivering, via a catheter, to said cavity a polymer composition comprising a ethylene vinyl alcohol copolymer, dimethyl sulfoxide and a water insoluble contrast agent selected from the group consisting of tantalum, tantalum oxide, tungsten and barium sulfate

wherein said delivery is conducted under conditions wherein a polymer precipitate forms in situ in the aneurysm cavity thereby blocking the aneurysm and further wherein said metallic coil becomes fixed against a vascular wall thereby anchoring an embolic site.

15. The method according to claim 14 wherein said water insoluble contrast agent is tantalum.

16. The method according to claim 14 wherein the polymer composition is injected into the aneurysm at a rate of about 0.05 to 0.3 cc/minute.

17. The method according to claim 14 wherein the polymer composition is injected into the aneurysm at a rate of at least 0.6 cc/minute.

18. A method for embolizing a vascular site in a patient'"'"'s blood vessel which method comprises

(a) introducing, via a catheter, at the vascular site to be embolized a non-particulate agent or a plurality of said agents;

and

(b) delivering, via a catheter, at the vascular site a prepolymer composition comprising a biocompatible prepolymer and a water insoluble contrast agent

wherein said delivery is conducted under conditions wherein said prepolymer polymerizes in situ at said vascular site thereby embolizing the blood vessel and further wherein said non-particulate agent becomes fixed against a vascular wall thereby anchoring an embolic site.

19. The method according to claim 18 wherein said prepolymer composition further comprises a biocompatible solvent.

20. The method according to claim 19 wherein said biocompatible solvent is selected from the group consisting of dimethylsulfoxide, ethanol, and acetone.