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Publication numberWO1999058183 A2
Publication typeApplication
Application numberPCT/US1999/010673
Publication date18 Nov 1999
Filing date13 May 1999
Priority date14 May 1998
Also published asCA2331000A1, CA2331000C, DE69936643D1, DE69936643T2, DE69941274D1, EP1077738A2, EP1077738B1, EP1803482A1, EP1803482B1, US6306105, US7470239, US7946999, US7955272, US20020019599, US20090149777, WO1999058183A3
Publication numberPCT/1999/10673, PCT/US/1999/010673, PCT/US/1999/10673, PCT/US/99/010673, PCT/US/99/10673, PCT/US1999/010673, PCT/US1999/10673, PCT/US1999010673, PCT/US199910673, PCT/US99/010673, PCT/US99/10673, PCT/US99010673, PCT/US9910673, WO 1999/058183 A2, WO 1999058183 A2, WO 1999058183A2, WO 9958183 A2, WO 9958183A2, WO-A2-1999058183, WO-A2-9958183, WO1999/058183A2, WO1999058183 A2, WO1999058183A2, WO9958183 A2, WO9958183A2
InventorsMaura Rooney, Joseph Richard, Andy Kapravy, Clifford M. Liu, Michael S. H. Chu, Tom Mirarchi
ApplicantScimed Life Systems, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: Patentscope, Espacenet
High performance coil wire
WO 1999058183 A2
Abstract
A high performance coil over-core guide wire. The guide wire incorporates a nickel-titanium core with a stainless steel coil to provide a wire with improved kink resistance and good pushability.
Claims  (OCR text may contain errors)
We claim:
1. A guide wire comprising:
an elongate core composed of a nickel-titanium alloy; and
a coil composed of a second material and surrounding a substantial portion
of the core.
2. The guide wire of claim 1 wherein the nickel-titanium alloy comprises a super-
elastic metal.
3. The guide wire of claim 1 wherein the nickel-titanium alloy comprises a linear-
elastic metal.
4. The guide wire of claim 1 wherein the second material comprises a nickel-
titanium alloy.
5. The guide wire of claim 4 wherein the nickel-titanium alloy comprises a super-
elastic metal.
6. The guide wire of claim 4 wherein the nickel-titanium alloy comprises a linear-
elastic metal.
7. The guide wire of claim 1 wherein the second material comprises stainless steel.
8. The guide wire of claim 1 wherein the second material comprises a precipitation
hardenable alloy.
9. The guide wire of claim 1 further comprising:
a polymer tip surrounding a distal portion of the core wire.
10. The guide wire of claim 9 wherein the polymer tip comprises a radio-opaque filler
whereby a distal tip of the guide wire may be more readily visible under fluoroscopy.
11. The guide wire of claim 1 wherein the coil comprises a single strand of wire.
12. The guide wire of claim 1 wherein the coil comprises a multi-filar strand.
13. The guide wire of claim 11 wherein the wire further comprises a rectangular cross-section.
14. The guide wire of claim 11 wherein the wire further comprises a circular cross- section.
15. The guide wire of claim 1 wherein the coil further comprises a pitch which varies
along the length of the coil.
16. The guide wire of claim 15 wherein the pitch of the coil varies such that a distal
end of the coil is more flexible then a proximal end of the coil.
17. The guide wire of claim 1 further comprising: a hypotube, joined to the core and bonded to the coil.
18. The guide wire of claim 1 wherein a bond is formed between the coil and the core.
19. The guide wire of claim 18 wherein the bond comprises a weld bond.
20. The guide wire of claim 18 wherein the bond comprises an adhesive bond.
21. A floppy-tipped guide wire comprising:
a core;
a coil surrounding at least a distal portion of the core, a distal end of the
coil extending distal of the distal portion of the core,
a tip bonded to the distal end of the coil; and a polymeric safety ribbon bonding the distal portion of the core to the tip.
Description  (OCR text may contain errors)

High Performance Coil Wire

Field of the Invention

The present invention generally relates to guide wires and their methods of

manufacture. Specifically, the present invention relates to guides wires made with a solid

core and surrounded by a coil. Those skilled in the art will recognize the benefits of

applying the present invention to similar fields not discussed herein.

Background of the Invention Guide wires are used in a variety of medical applications including intravascular, gastrointestinal, and urological. A common vascular application is Percutaneous

Transluminal Coronary Angioplasty (PTCA). This procedure can involve inserting a

guide wire through an incision in the femoral artery near the groin, advancing the guide

wire over the aortic arch, into a coronary artery, and across a lesion to be treated in the heart. Similarly, angioplasty performed in other parts of the anatomy is called Percutaneous Transluminal Angioplasty (PTA) and may also involve the use of a guide

wire. Typical vascular guide wires are 50 cm or 300 cm in length, and are 0.010-0.038

inches in diameter depending upon the application.

Common gastrointestinal uses of guide wires include endoscopic procedures in

which an endoscope may be inserted into the mouth and advanced through the esophagus

to the bile duct, the cystic duct, or the pancreatic duct. A guide wire is then threaded

through a lumen in the endoscope and into the bile duct, cystic duct, or pancreatic duct.

Once the distal tip of the guide wire is located in a position desired to be treated, a

catheter having a medical instrument on it distal end is advanced over the guide wire and to the treatment area. The guide wire and the catheter may then be observed through the

endoscope as treatment occurs.

Urological uses of guide wires include the placement of ureteral stents. Ureteral

stenting is required when the normal flow of urine from the kidney into the bladder is

compromised perhaps by tumor growth, stricture, or stones. Generally, the procedure

involves the insertion of a ureteroscope through the urethra and into the bladder. A guide

wire is then advanced through the ureteroscope and into a ureter. The wire is then forced

through the compromised portion of the ureter. Once the guide wire is in place, a ureteral

stent is advanced over the guide wire and into position in the ureter. The guide wire may

then be removed and the stent will maintain the patency of the fluid path between the

kidney and the bladder. The procedures described above are but a few of the known uses

for guide wires.

Pushability, kink resistance, torqueability and bendability are closely related and

important features of a guide wire. It is important that force applied at the proximal end

of a guide wire is completely transferred to the distal end of the guide wire. Very stiff

wires often provide good pushability (axial rigidity) but poor kink resistance. Kink

resistance is measured by the ability of the guide wire to be forced into a relatively tight

bend radius without permanently deforming the wire. A guidewire must exhibit good

bendability. This characteristic is a balance between adequate flexibility to navigate a

tortuous lumen and suitable rigidity to support tracking of another device such as a

catheter. Torqueability is closely related to the torsional rigidity of the wire and is

ultimately demonstrated by how well rotation imparted to the proximal end of the guide

wire is translated to the distal end of the guide wire. Conventional guide wires are made of carbon steel or stainless steel. More

recently, guide wires made of super-elastic alloys have been used. A super-elastic or

pseudoelastic metal guide wire was taught in U.S. Patent 4,925,445 to Sakamoto. In U.S.

Patents 5,238,004 to Sahatjian and 5,230,348 to Ishibe the use of an elastic metal alloy

was taught. Sahatjian '004 further teaches that elastic metals may be heat treated to form

bends in the wire core and that centerless grinding may be used to create certain wire

profiles.

Several different types of guide wires are well known in the art. One type of wire

is characterized by a solid metal core surrounded by a metal coil. Typical metals for the

core may include spring steels and stainless steels. The distal tip of the core may also be

ground to a taper to provide added flexibility near the tip. Coils may be made of the same

variety of metals used as core materials. The coil may be made of round wire or flat wire

and may surround the entire length of the core or only a portion of the core. The coil

usually is formed by helically wrapping the wire around a mandrel, removing the

mandrel, and inserting the core into the coil. The pitch of the wire may be varied along

the length of the coil to vary the stiffness of the coil.

High performance guide wires usually possess high kink resistance and excellent

wire movement. The basic construction of a high performance wire is a Nitinol core

surrounded by a lubricious coating. Unfortunately, Nitinol guide wires suffer from

diminished pushability because the highly elastic Nitinol absorbs some of the force

imparted to the proximal end of the wire. An improved high performance wire would

provide better pushability to conventional super-elastic wires. Traditional coil over core wires provide good axial stiffness and hence improved

pushability. Traditional coil over core wires also provide dramatically improved kink

resistance over stainless steel wires. However, because the coils tend to wind up on

torque, coil over core wires tend to provide reduced torque transmission. Therefore, it

would be advantageous to provide a coil over core wire with the torque transmission of a

high performance wire.

Summary of the Invention

The present invention overcomes the deficiencies of the prior art by providing a

coil over core guide wire which has the kink resistance and wire movement of a super-

elastic wire and the pushability and torque transmission of a coil over core wire. The

guide wire has a nickel-titanium alloy core with a tapered distal tip. The core may be super-elastic or linear elastic.

A coil surrounds most of the core and may be bonded to the core. The coil may be

stainless steel or nickel-titanium. The coil may be made of flat wire or round wire and

may be made of a single strand or multifilar strands and may be a single coil or cross-

wound coil.

The guide wire may further have a polymer tip which may be loaded with a radio-

opaque material. The wire may also be coated with lubricious coatings. The polymer tip

may also form a floppy tip without a safety ribbon.

Brief Description of the Drawings

Figure 1 is a cross-section of a first embodiment of the guide wire.

Figure 2 is a cross-section of a second embodiment of the guide wire. Detailed Description of the Invention

The following detailed description should be read with reference to the drawings

in which like elements in different drawing are numbered identically. The drawings,

which are not necessarily to scale, depict selected embodiments and are not intended to

limit the scope of the invention.

Examples of constructions, materials, dimensions, and manufacturing processes

are provided for selected elements. All other elements employ that which is known to

those skilled in the field of the invention. Those skilled in the art will recognize that

many of the examples provided have suitable alternatives that may also be used.

Figure 1 shows a first embodiment of the guide wire 10. Core 20 may be 50-450

cm in length and 0.008-0.038 inches in diameter depending on the medical application.

The distal portion 25 of core 20 may be tapered to provide flexibility to guide wire 10.

Preferably the tapered distal portion 25 is formed by grinding 5-20 cm of core 20. The tapered distal portion 25 may be ground into a conical shape with a circular cross-section

or stamped such that it has a rectangular cross-section.

Core 20 may be formed of a super-elastic material such as the alloys of nickel and

titanium, commonly known as Nitinol. While Nitinol is the most common super-elastic

material, any of a variety of other super-elastic materials may be used for core 20. Other

alloys by chemical name include; CuAINi, CuSn, CuZn, InTi, NiAl, FePt, MnCu, and

FeMnSi. A detailed discussion of super-elastic alloys and their processing is presented in

US Patent 4,925,445 to Sakamoto and is herein incorporated by reference.

In addition to super-elastic materials, linear-elastic materials may be used. Linear-

elastic materials are describe in US Patent 5,238,004 to Sahatjian which is also incorporated by reference. In general, linear-elastic materials are composed of the same

alloys above. However, different material processing strategies are used to provide a wire

which has many of the important characteristics of a super-elastic material without some

of the difficulties related to machining, specifically grinding. As such, core 20 may

preferably be formed of a linear-elastic alloy of nickel-titanium.

Surrounding core 20 is coil 30. Coil over core wires are well known in the art and

are described in detail in US Patent 5,147,317 to Shank which is incorporated by

reference. Coil 30 may be made of a variety of metallic materials including super-elastic

or linear-elastic materials such as Nitinol, radio-opaque materials such as gold or

tungsten, precipitation hardenable alloys such as the non-ferrous cobalt-based alloys

MP35N or Elgiloy™ and the ferrous alloys such as K91 from Sanvic Corp. and PH455

from Carpenter, or more conventional stainless steel alloys such as 304. Preferably coil

30 may be 0.001-0.015 inches in diameter, and made of 304 stainless steel.

Coil 30 is wrapped around substantially the entire length of core 20. Preferably,

coil 30 is not wrapped around the tapered distal portion 25 of core 20. Coil 30 may be

formed of flat ribbon ranging in dimensions 0.001 - 0.003 inches in thickness by 0.005 to

0.015 inches in width . Coil 30 is wrapped in a helical fashion about core 20 by

conventional winding techniques. The pitch of adjacent turns of coil 30 may be tightly

wrapped so that each turn touches the succeeding turn or the pitch may be set such that

coil 30 is wrapped about core 20 in an open fashion shown at 35. Preferably, the pitch

coil 30 is such that the coils are tightly wrapped over most of the proximal portion of core

20 with the pitch of each turn changing such that coil 30 has an open wrap shown at 35 near the distal end of core 20. Varying the pitch of coil 30 allows guide wire 10 to have a

more flexible distal segment.

Alternatively, coil 30 may be formed of cross-wound multifilar or multifilar single

coil wire. Multifilar cross-wound coils are described in US Patent 4,932,419 to de

Toledo which is herein incorporated by reference. A cross-wound multifilar coil consists

essentially of a first inner coil of multiple coil wires wound in a first helical direction and

a second outer coil of multiple coil wires disposed about the first coil and wound in a

second opposite helical direction. Coil over core wires tend to wind up and store energy

when torqued rather than transmitting the torque. Multifilar coils provides less wind up

and therefore lessen the potential for the distal tip of the wire to whip while the proximal

end is being turned.

Bonding core 20 to coil 30 also improves the torque transmission of guide wire

10. Coil 30 may be bonded to core 20 along the length of core 20 or in discrete sections.

Bonding may be achieved in a variety of ways including using adhesives, brazing,

welding, crimping, and swaging. Welding may be done through any of the techniques

known in the art including spot welding using laser or resistance welding or ball welding

using laser or plasma welding. Soldering may be done through any of the techniques

known in the art and must include the step of preparing the surface of the Nitinol core 20

by plating or etching. Preferably the coil 30 will be bonded to the core 20 by laser spot

welding thereby removing the need for preparing the surface of the core 20. Laser spot

welding is also advantageous because it may be done through coatings.

An alternative method of bonding the coil 30 to the core 20 is to provide a

stainless steel hypotube (not shown) with an inner diameter dimensioned to closely fit about core 20. The stainless steel hypotube may then be crimped onto core 20 and the

coil 30 wound about the hypotube. The hypotube then provides a surface which is much

easier to bound to a stainless steel coil 30 using conventional methods. Metal a foils or

other materials may also be used as an intermediate which facilitates bonding between the

coil 30 and the core 20.

Yet another bonding method utilizes the polymer jacket 40 of the distal tip. The

polymer may be applied in a manner that allows the polymer to flow between the coil and

core. The polymer will provide a high integrity bond which will help to prevent the

polymer jacket from separating from the coil 30 and bond the coil to core 20. In addition

to the these improvements, the polymer coating will make a better transition from the

core 20 to the distal portion 25. A tip bonded in this manor provides a further

improvement by producing coloration differences between the coil wire and polymer.

These differences act as stripes for the detection of guidewire advance in endoscopy

application.

The distal portion 25 of core wire 20 may further include a polymer tip 40.

Polymer tip 40 serves several functions. Polymer tip 40 improves the flexibility of the

distal portion 25 of core wire 20. Choice of polymers for polymer tip 40 will vary the

flexibility of the distal portion 25 of core wire 20. For example, polymers with a low

durometer or hardness will make a very flexible or floppy tip. Conversely, polymers with

a high durometer will make a wire tip which is stiffer.

Polymer tip 40 also provides a more atraumatic tip for guide wire 10. An

atraumatic tip is better suited for passing through fragile body passages. Finally, polymer

tip 40 may act as a binder for radio-opaque materials. Loading polymers with radio- opaque materials is well known in the art for producing a bright image under fluoroscopy

and thereby allowing the user of guide wire 10 a better understanding of where the distal

portion 25 of guide wire 10 is located within a patient's body. Suitable medical grade

radio-opaque materials include tungsten, platinum, and iridium.

Suitable polymeric materials for polymer tip 40 include urethanes, elastomeric

nylons such as Pebax, silicones, and co-polymers. Polymer tip 40 may be a single

polymer, multiple layers, or a blend of polymers.

Coating (not shown) may also be done to the wire proximal to polymer tip 40.

Hydrophobic coatings such as fluoropolymers provide a dry lubricity which improves

guide wire handling and device exchanges. A second lubricious polymer (not shown)

may coat distal portion 25 of guide wire 10 or the entire wire 10. Lubricious coatings

improve steerability and improve lesion crossing capability. Suitable lubricious polymers

are well known in the art and may include hydrophilic polymers.

Guide wire 10 may further include a colored coating. Colored guide wires are

described in detail in US Patent 5,739,779 to Rowland which is herein incorporated by

reference. In general, colored coatings may improve the visibility of the guide wire when

it is being used in an endoscopic procedure. Striping may also be done. Striping allows

the physician to gauge wire movement and position. Striping may be achieved by spray

coating different colors on the wire 10. Another way to stripe the wire 10 is to coat the

wires of coil 30 prior to winding.

Figure 2 depicts a second embodiment of the high performance coil wire where

like elements are similarly numbered. All design advantages, materials of construction,

and methods of manufacture are similar to those described above unless explicitly modified below. Guide wire 10 is comprised of a solid core 20 surrounded by a coil 30.

The distal portion 25 of core 20 may be tapered as described above or preferably is not

tapered. Similar to the embodiment of Figure 1, the distal portion 35 of coil 30 changes

pitch to provide a softer less traumatic tip.

Guide wire 10 further includes a rounded tip 37. Tip 37 may be polymeric or a

metal tip welded to the distal portion 35 of coil 30. Unlike common spring tipped guide

wires, guide wire 10 does not have a safety ribbon connecting core 20 to tip 37. Instead

guide wire 10 may include a polymer 40 which may be flowed into the space between

coils 35 and the space between the distal portion 25 and tip 37. Suitable polymers are

described above where choice of polymer may control the flexibility of the tip. Polymer

40 may also be loaded with radio-opaque materials. Finally, guide wire 10 may be coated

as described above and may also include various colors or stripes. The distal portion of

guide wire 10 is thereby provided with a very floppy tip which uses polymer 40 as a

safety ribbon instead of a metallic safety ribbon. Guide wire 10 is provided with the

advantage that core 20 does not need to be ground.

While the specification describes the preferred designs, materials, methods of

manufacture and methods of use, those skilled in the art will appreciate the scope and

spirit of the invention with reference to the following claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US49254459 Feb 198915 May 1990Fuji Terumo Co., Ltd.Guide wire for catheter
US51473174 Jun 199015 Sep 1992C.R. Bard, Inc.Low friction varied radiopacity guidewire
US523034811 Oct 199127 Jul 1993Nippon Seisen Co., Ltd.Guide wire for a catheter
US523800430 Sep 199224 Aug 1993Boston Scientific CorporationHigh elongation linear elastic guidewire
US573977920 Aug 199614 Apr 1998Sanyo Electric Co., Ltd.Encoding circuit and decoding circuit
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
WO2002005886A1 *17 Jul 200124 Jan 2002Scimed Life Systems, Inc.Guide wire stiffness transition element
WO2002043798A1 *1 Dec 20006 Jun 2002Micrus CorporationComposite guidewire
US660220719 Jul 20005 Aug 2003Scimed Life Systems, Inc.Guide wire stiffness transition element
US822256615 Feb 200517 Jul 2012Boston Scientific Scimed, Inc.Elongated intracorporal medical device
Classifications
International ClassificationA61M25/09, A61M25/01, A61B5/00
Cooperative ClassificationA61M25/09, A61M2025/09083, A61M2025/09175
European ClassificationA61M25/09
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