High viscosity embolizing compositions

• US 6,962,689 B2
• Filed: 10/11/2001
• Issued: 11/08/2005
• Est. Priority Date: 05/21/1999
• Status: Expired due to Term

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Micro Therapeutics, Inc. (Medtronic Plc)
• Inventors: Greff, Richard J., Tran, Chinh N., Whalen, Thomas J., Roth, Noah M.
• Primary Examiner(s): Padmanabhan, Sreeni
• Assistant Examiner(s): SHARAREH, SHAHNAM J
• Application Number:
  US09/973,951
• Publication Number:
  US 20020090339A1
• Time in Patent Office: 1,489 Days
• Field of Search: 424/9.45, 424/9.4, 424/9.455, 514/708, 604/264, 604/49
• US Class Current: 424/9.45
• CPC Class Codes: A61K 49/0002 General or multifunctional contrast agents, e.g. chelated agents
• CPC Class Codes: A61K 49/0409 Physical forms of mixtures of two different X-ray contrast-enhancing agents, containing at least one X-ray contrast-enhancing agent which is not a halogenated organic compound
• CPC Class Codes: A61L 24/001 Use of materials characterised by their function or physical properties
• CPC Class Codes: A61L 24/02 containing inorganic materials
• CPC Class Codes: A61L 24/046 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043 takes precedence
• CPC Class Codes: A61L 24/06 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043, A61L24/046 take precedence
• CPC Class Codes: A61L 24/08 Polysaccharides A61L24/043 takes precedence
• 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 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body

Abstract

Disclosed are novel compositions for embolizing blood vessels which are particularly suited for treating vascular lesions via catheter deliver.

Claims

1. A method for enhancing the formation of a solid, non-migratory coherent mass at a selected vascular site of a mammal which method comprises:

(a) placing a delivery device having an ejection port at a selected vascular site in a mammal;

(b) delivering through the ejection port of the delivery device a composition capable of embolizing an aneurysm at a vascular site comprising;

a. a biocompatible polymer at a concentration of from about 12 to about 50 weight percent based on the total weight of the composition;

b. a biocompatible contrast agent wherein a sufficient amount of said contrast agent is employed in said composition to effect visualization in vivo; and

c. a biocompatible solvent which solubilizes said biocompatible polymer;

wherein sufficient amounts of said polymer are employed in said composition such that upon delivery to said vascular site a polymer precipitate forms which embolizes said vascular site;

and further wherein the biocompatible polymer has a molecular weight and/or concentration sufficient to impart to the composition a viscosity of at least about 150 cSt at 40°

C.

3. The method according to claim 1 or claim 2 wherein, prior to (b) above, a blood flow attenuation device is inserted immediately upstream the ejection port of said catheter.

4. The method according to claim 3 wherein, said blood flow attenuation device is an inflatable microballoon which permits both normal and attenuated blood flow depending upon whether the microballoon is deflated or inflated.

5. The method according to claim 1 or claim 2 wherein said composition has a viscosity of at least about 200 cSt at 40 0°

C.

6. The method according to claim 5 wherein said composition has a viscosity of at least about 500 cSt at 40°

C.

7. The method according to claim 6 wherein said composition has a viscosity of from about 500 to 5,000 cSt at 40°

C.

8. The method according to claim 1 or claim 2 wherein said composition has a migration distance from the point of injection of less than 25 mm.

9. The method according to claim 1 or claim 2 wherein said biocompatible solvent is selected from the group consisting of ethyl lactate, dimethylsulfoxide, ethanol and acetone.

10. The method according to claim 9 wherein said biocompatible solvent is dimethylsulfoxide.

11. The method according to claim 1 or claim 2 wherein said contrast agent is a water insoluble contrast agent.

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

13. The method according to claim 12 wherein said contrast agent is tantalum.

14. The method according to claim 1 or claim 2 wherein said contrast agent is a water soluble contrast agent.

15. The method according to claim 1 or claim 2 wherein said biocompatible polymer is a non-biodegradable, biocompatible polymer.

16. The method according to claim 15 wherein said non-biodegradable, biocompatible polymer is selected from the group consisting of cellulose acetates, ethylene vinyl alcohol copolymers, hydrogels, polyacrylonitrile, polyvinylacetate, cellulose acetate butyrate, nitrocellulose, copolymers of urethane/carbonate, copolymers of styrene/maleic acid, and mixtures thereof.

17. The method according to claim 16 wherein said biocompatible polymer is an ethylene and vinyl alcohol copolymer.

18. The method according to claim 1 or claim 2 wherein said biocompatible polymer is a biodegradable, biocompatible polymer.

2. A method for enhancing the formation of a solid, non-migratory coherent mass at a selected vascular site of a mammal which method comprises:

(a) placing a delivery device having an ejection port at a selected vascular site in a mammal;

(b) delivering through the ejection port of the delivery device a composition capable of embolizing an aneurysm at a vascular site comprising;

a) a biocompatible polymer at a concentration of from about 12 to about 50 weight percent;

b) a biocompatible contrast agent at a concentration of from about 10 to about 40 weight percent; and

c) a biocompatible solvent from about 10 to 88 weight percent;

wherein the weight percents of the biocompatible polymer, contrast agent, and biocompatible solvent are based on the total weight of the composition;

and further wherein the biocompatible polymer has a molecular weight and/or concentration sufficient to impart to the composition a viscosity of at least about 150 cSt at 40°

C.