Detachable multidiameter vasoocclusive coil
A vasoocclusive helical coil having a proximal end that carries a coupling member for attaching the coil to the distal end of a wire and a proximal winding that has a smaller diameter than adjacent windings whereby the proximal end of the coil is positioned radially inwardly of the main body of the coil.
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This invention is in the field of vasoocclusion devices. More particularly it relates to a helical vasoocclusion coil one end of which is adapted to be detachably connected to a wire and in which the helix winding at that end has a smaller diameter than the adjacent windings.
BACKGROUNDVasoocclusion devices are surgical instruments that are placed within vessels, typically via a catheter, to block the vessel or to fill a vascular cavity such as an aneurysm. One type of vasoocclusion device is in the form of a helical wire coil. See U.S. Pat. No. 4,994,069. The coil may be placed at the desired site in several ways. One involves loading the coil into the lumen of a catheter whose distal end is located at the site. The coil is then advanced through the catheter lumen using a pusher and expelled from the distal end of the catheter. Another involves detachably coupling the coil to the distal end of a wire, advancing the assembly to the site using a catheter, and uncoupling the coil from the wire at the site. U.S. Pat. Nos. 5,234,437; 5,250,071; 5,261,916; 5,304,195; 5,312,415; and 5,350,397 describe coils that are detachably coupled to a wire.
Detachable coils carry a member on their proximal end that detachably engages or interlocks with a member on the distal end of the wire. A problem experienced with such coils is that the member carried on the coil is oriented tangentially to the helical diameter of the coil. As such, when the coil is decoupled, the member extends tangentially outwardly from the helix diameter and may engage the vessel wall. (See
A principal object of this invention is to provide a detachable helical vasoocclusive coil in which the member that attaches to the wire is not oriented tangentially to the diameter of the coil. Accordingly, the coils of this invention are less likely to injure the vessel wall.
DISCLOSURE OF THE INVENTIONOne aspect of the invention is a helical vasoocclusion coil for use with a wire having a distal end, said coil having: (a) a proximal end adapted to detachably couple to the distal end of the wire; (b) a distal end; (c) a first diameter intermediate (a) and (b); and (d) a second diameter smaller than said first diameter at said proximal end whereby said proximal end is positioned radially inwardly of said first diameter.
Another object of the invention is an assembly for use in occluding a vessel or a cavity within a vessel comprising: a wire having a distal end that carries a first coupling member; and a helical vasoocclusion coil having: (i) a proximal end that carries a second coupling member that is detachably coupled to the first coupling member; (ii) a distal end; (iii) a first diameter intermediate (i) and (ii); and (iv) a second diameter smaller than said first diameter at said proximal end whereby the first coupling member is positioned radially inwardly of said first diameter.
BRIEF DESCRIPTION OF THE DRAWINGSIn the drawings, which are not to scale:
Coil 10 is composed of a multiplicity of windings 11 and has a distal end 12 and a proximal end 13. The windings of coil 10 will typically be made of a metal such as platinum, gold, rhodium, rhenium, palladium, tungsten and the like or alloys of such metals. These metals have significant radiopacity and their alloys may be tailored to provide desired degrees of stiffness and flexibility. The windings may be made of other suitable biocompatible materials such as polymers or composites of metals and polymers.
While the cross-section of the windings of the coil 10 is circular, windings having other cross-sectional shapes, e.g. elliptical, trapezoidal, rhombic, rectangular, and square, may be used. Circular cross-sectional windings will typically have a diameter of about 0.01 to about 0.50 mm. Correspondingly, the diameter of the helix, D (
As shown in
While not shown in the drawings, the coil may have fibers attached to it to facilitate embolization. See U.S. Pat. Nos. 5,304,194; 5,476,472 and 5,382,259, the relevant disclosures of which are incorporated herein by reference. Other modifications of the above described modes for carrying out the invention that are considered obvious or equivalent by those of skill in the medical device art and related arts are intended to be within the scope of the following claims.
Claims
1. A helical vasoocclusion coil for use with a wire having a distal end, said coil having:
- (a) a proximal end adapted to detachably couple to the distal end of the wire;
- (b) a distal end;
- (c) a first diameter intermediate (a) and (b); and
- (d) a second diameter smaller than said first diameter at said proximal end whereby said proximal end is positioned radially inwardly of said first diameter.
2. The coil of claim 1 wherein the second diameter is also at the distal end of the coil whereby the distal end of the coil is also positioned radially inwardly of said first diameter.
3. The coil of claim 1 wherein said proximal end has a coupling member that detachably interlocks with the distal end of the wire.
4. An assembly for use in occluding a vessel or a cavity within a vessel comprising:
- (a) an elongated wire having a distal end that carries a first coupling member; and
- (b) a helical vasoocclusion coil having: (i) a proximal end that carries a second coupling member that is detachably coupled to the first coupling member; (ii) a distal end; (iii) a first diameter intermediate (i) and (ii); and (iv) a second diameter smaller than said first diameter at said proximal end whereby the first coupling member is positioned radially inwardly of said first diameter.
5. The assembly of claim 4 wherein the second diameter is also at the distal end of the coil whereby the distal end of the coil is also positioned radially inwardly of said first diameter.
Type: Application
Filed: Aug 31, 2004
Publication Date: Feb 10, 2005
Applicant: Target Therapeutics, Inc. (Fremont, CA)
Inventors: Christopher Ken (San Mateo, CA), Abhijit Acharya (Saratoga, CA)
Application Number: 10/931,517