High polymer gel and vascular lesion embolizing material comprising the same

• US 5,624,685 A
• Filed: 04/03/1995
• Issued: 04/29/1997
• Est. Priority Date: 10/16/1991
• Status: Expired due to Term

• Current Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Original Assignee: Terumo Kabushiki Kaisha (Terumo Corporation)
• Inventors: Takahashi, Toru, Goto, Katsuya, Nakamura, Hideki
• Primary Examiner(s): Webman, Edward J.
• Application Number:
  US08/416,530
• Time in Patent Office: 757 Days
• Field of Search: 424/484, 424/488, 424/9.4, 424/9.5, 424/485, 424/451, 424/455, 252/315.3, 252/315.4, 524/916, 514/944
• US Class Current: 424/488
• CPC Class Codes: A61L 2430/36 for embolization or occlusion, e.g. vaso-occlusive compositions or devices
• CPC Class Codes: A61L 31/042 Polysaccharides
• CPC Class Codes: A61L 31/14 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/145 Hydrogels or hydrocolloids
• CPC Class Codes: A61P 7/04 Antihaemorrhagics; Procoagulants; Haemostatic agents; Antifibrinolytic agents
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: C08L 5/04 Alginic acid; Derivatives thereof

Abstract

The improved vascular lesion embolizing material comprises a high-polymer gel capable of absorbing water in an amount of 10 ml/g and more. The high-polymer gel is preferably such as is produced by first permitting a solution containing a water-soluble high polymer to be precipitated in a solution containing polyvalent cation, said high polymer having a plurality of monovalent anionic functional groups, and then immersing the resulting precipitate in a salt solution. The material will swell upon contact with blood and is capable of embolizing a focal lesion in a blood vessel without causing any adverse effects on the living body. The swell time can be shortened if the embolizing material is made of a high-polymer gel that has been treated with a salt solution after precipitation.

Claims

1. A method for treating a vascular lesion using a vascular lesion-embolizing material, said method comprising the steps of:

applying the vascular lesion-embolizing material in the interior of the vascular lesion to bring said embolizing material into contact with blood flowing through the vascular lesion, said vascular lesion-embolizing material comprising a dried water-absorbent polymer gel capable of absorbing water in an amount of at least 10 ml/g when measured by dipping the dry polymer gel in a physiological saline; and

allowing said embolizing material to swell thereby completing the embolization of the vascular lesion;

said polymer gel being produced by precipitating a solution containing a water-soluble polymer of an alkali metal salt of alginic acid in a solution containing a polyvalent cation, immersing the resulting precipitate in a salt solution, and then drying the precipitate.

2. The method according to claim 1, wherein said embolizing material further comprises an X-ray contrast medium.

3. The method according to claim 1, wherein said polyvalent cation is a calcium ion.

4. The method according to claim 1, wherein said polymer gel is bound with a binder.

5. The method according to claim 1, wherein said vascular lesion is in a cerebrum, spine, abdominal port or limb.

6. A method for treating a vascular lesion using a vascular lesion-embolizing material, said method comprising the steps of:

applying the vascular lesion-embolizing material in the interior of the vascular lesion to bring said embolizing material into contact with blood flowing through the vascular lesion, said vascular lesion-embolizing material comprising a dried water-absorbent polymer gel capable of absorbing water in an amount of at least 10 ml/g when measured by dipping the dry polymer gel in a physiological saline, and a blood coagulating substance; and

allowing said embolizing material to swell thereby completing the embolization of the vascular lesion and, simultaneously, to dissolve said blood coagulating substance thereby coagulating blood absorbed in the swollen embolizing material;

said polymer gel being produced by precipitating a solution containing a water-soluble polymer of an alkali metal salt of alginic acid in a solution containing a polyvalent cation, immersing the resulting precipitate in a salt solution, and then drying the precipitate.

7. The method according to claim 6, wherein said embolizing material further comprises an X-ray contrast medium.

8. The method according to claim 6, wherein said polyvalent cation is a calcium ion.

9. The method according to claim 6, wherein said polymer gel is bound with a binder.

10. The method according to claim 6, wherein said vascular lesion is in a cerebrum, spine, abdominal port or limb.