WO1997016113A1

WO1997016113A1 - Guide wire extension assembly and components thereof

Info

Publication number: WO1997016113A1
Application number: PCT/US1996/014701
Authority: WO
Inventors: Dignah B. Quiachon; Dennis L. Brooks; Deepak R. Gandhi; Mir A. Imran
Original assignee: Intella Interventional Systems, Inc.
Priority date: 1995-11-03
Filing date: 1996-09-13
Publication date: 1997-05-09
Also published as: AU6976496A

Abstract

This invention is a guide wire assembly for use in a vascular system of a patient in a medical procedure comprising a guide wire adapted to extend into a patient's vascular system. The guide wire has a proximal extremity (12) extending out of the patient. A guide wire extension (13) is provided which has a distal extremity. A connector (36) is provided for forming a repetitive connection between the proximal extremity of the guide wire (12) and the distal extremity of the guide wire extension. The connector is formed of a male (31) and female (16) parts. At least one of the male and female parts is formed of a super-elastic memory material.

Description

GUIDE WIRE EXTENSION ASSEMBLY AND COMPONENTS THEREOF

This invention relates to a guide wire extension assembly and components thereof.

Extendable guide wire systems have heretofore been provided as for example as disclosed in U.S. Letters Patent 4,827,941. However, such extendable guide wire assemblies have not provided capabilities for electrical functions. In addition, the guide wires utilized in the guide wire assemblies in U.S. Letters Patent 4,827,941 have proximal extremities which have been treated by grinding or coining. This treatment has been found to be an expensive and time consuming procedure, particularly when it is realized that only approximately 30% of such guide wires are utilized in procedures in which extension capabilities are required. There is therefore need for new and improved guide wire extension assembly which overcomes these deficiencies. In general, it is an object of the present invention to provide a guide wire extension assembly and components thereof to eliminate the necessity for providing expensive treatment of the proximal extremities of the guide wires. Another object of the invention is to provide a guide wire extension assembly of the above character in which additional post processing steps are not required on the proximal extremity of the guide wire.

Another object of the invention is to provide a guide wire extension assembly of the above character having a connector assembly providing the extension capability in which a shape memory material is utilized in the connector assembly.

Another object of the invention is to provide a guide wire extension assembly of the above character in which it is unnecessary to increase the overall diameter of the assembly to accommodate the extension capabilities.

Another object of the invention is to provide a guide wire extension assembly of the above character which can be readily and economically manufactured. Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in detail in conjunction with the accompanying drawings.

Figure 1 is a partial side elevational view of a guide wire assembly incorporating the present invention with the guide wire and the guide wire extension being separated from each other and including the mating male and female parts comprising the connector assembly providing the extension capability. Figure 2 is a side elevational view similar to that shown in Figure 1 but with the guide wire and the extension guide wire being mated to each other.

Figure 3 is a cross sectional view taken along the line 3-3 of Figure 2.

Figure 4 is a partial side elevational view showing an alternative shape for the superelastic sleeve or female part utilized in the extension guide wire shown in Figure 1.

Figure 5 is a side elevational view similar to Figure 1 but showing the superelastic characteristics of the mating connector assembly being provided in the proximal extremity of the guide wire.

Figure 6 is a cross sectional view similar to Figure 2 but showing the parts shown in Figure 5 mated to each other.

In general, the guide wire extension assembly of the present invention which is for use in a patient's vascular system in a medical procedure is comprised of a guide wire adapted to extend into the patient's vascular system. The guide wire has a proximal extremity extending out of the patient. The guide wire extension assembly also includes an extension guide wire having a distal extremity. Connection means is provided for forming repetitive connections between the proximal extremity of the guide wire and the distal extremity of the extension guide wire. The connection means is formed of male and female parts, at least one of which is formed of a superelastic shape memory material.

More in particular as shown in drawings, the guide wire extension assembly 11 which is comprised of a guide wire 12 and a guide wire extension 13 which are provided with a connector assembly 16 forming repetitive connection means by use of two separate parts 17 and 18 in which one of the parts 17 is a male part and the other part 18 is a female part which are adapted to mate with each other to permit repeated connection and disconnection of the guide wire extension from the guide wire 12 .

The guide wire 12 is of the type described in copending application Serial No. 08/331,216, filed October 28, 1994, and as described therein is formed of a suitable material such as stainless steel and has a diameter ranging from .010" to .018" and preferably a diameter of approximately .012". The core wire 21 is provided with a proximal extremity 21a which as shown is generally cylindrical and is provided with a rounded end surface 22. The portion 21a of the core wire 21 is bare and preferably has a diameter .012" and a suitable length as for example 11 millimeters. A polyimide insulating layer 26 is provided on the core wire 21 and extends distally beyond the bare portion 21a. A conductive layer 27 formed of a suitable material such as a silver ink is provided on the exterior surface of the polyimide layer 26 and serves as a second electrical conductor with the core wire 21 serving as a first electrical conductor as described in said copending application Serial No. 08/331,216, filed October 28, 1994. The conductive layer 27 is disposed distally on the insulating layer 26 by a suitable distance as for example 1.5 millimeters. The guide wire 12 can have a suitable length as for example 175 centimeters. The guide wire extension 13 is comprised of a wire

31 which is circular in cross section and has a suitable length as for example 125 to 175 centimeters. It is formed of a suitable material such as stainless steel having a diameter ranging from .010" to .018" and preferably a diameter of .012". In the embodiment of the invention shown in Figures 1 and 2, the connector assembly 16 takes the form of a male part 17 which is the proximal extremity 21a of the core wire 21 and a female part 18 of the guide wire extension 13. The female part 18 consists of a sleeve or tubular member 36 formed of a suitable superelastic shape memory material such as Nitinol.

As can be seen from Figure 1, the sleeve or tubular member 36 has proximal and distal extremities 37 and 38 and is provided with at least one bend and as shown is provided with first and second spaced apart bends or undulations 41 and 42 disposed between the proximal and distal extremities 37 and 38. The bends 41 and 42 can be formed in a suitable manner in the sleeve 36. The sleeve 36 is selected to have the desired dimensions. Thus for example for use with extension wire 31 having an outside diameter of .012". The sleeve 36 is provided with a bore 46 having a corresponding diameter of .012". The sleeve can have an outside diameter of .015" to provide a wall thickness of 0.015". If desired, the exterior diameter can be reduced to 0.014" to provide a wall thickness of 0.001") . It should be appreciated that the extension wire 31 can have any suitable diameter as for example ranging from .010" to .018" and greater if desired. The sleeve 36 is correspondingly dimensioned. The sleeve 36 can have a suitable length as for example 10-50 millimeters and preferably a length of approximately 25 millimeters.

In forming the first and second bends 41 and 42, it has been found that it is desirable to utilize a temporary core or mandrel (not shown) of a slightly smaller diameter than the diameter of the bore 46 as for example .009". After the temporary core or mandrel has been placed in the bore 46 of the sleeve 36 the sleeve can then be fastened in a suitable jig or fixture (not shown) as or example a stainless steel plate of 1/2" in thickness and having upstanding pins (not shown) protruding therefrom defining the desired wavy or undulating pattern for the sleeve. The sleeve 36 with the temporary core therein is placed between the pins so that it is forced to assume the desired undulating pattern as for example a pattern having the two bends shown in Figure 1. After this has been accomplished, the assembly of the fixture with the tubular member or sleeve 36 thereon is placed in an oven so that the deformation which has been provided in the sleeve 36 at room temperature can be placed in a shape memory incorporated into the tubular member or sleeve 36. This can be accomplished in a suitable manner such as by treating the assembly at a temperature of 500°C for approximately 5 minutes. However, it should be appreciated that temperatures from 450-500°C can be utilized with appropriate adjustments in time with approximately 15 minutes at 450°C or a few seconds as for example 30 seconds at 550°C centigrade.

After the sleeve 36 has been subjected to this temperature, for the desired amount of time, it can be withdrawn from the oven and permitted to cool to room temperature after which it can be removed from the fixture. The fixture with the sleeve 36 therein can be cooled more rapidly by placing it under a running tap water or alternatively dipping the same in a bucket or container of cool water to bring it down close to room temperature so that it can be handled by hand. Thereafter the cylindrical mandrel can be withdrawn from the sleeve 36. The sleeve 36, because of its flexibility, will permit this withdrawal. As soon as the mandrel has been withdrawn, the sleeve will return to the memorized shape of its shape memory incorporated in the mandrel and forming undulations provided by the first and second bends 41 and 42.

After the sleeve 36 has been treated as hereinbefore described to impart into it the desired wavy or undulating shape with one or more bends therein into its shape memory, the proximal extremity 37 of the sleeve can be secured to the distal extremity 31b of the extension wire 31 in a suitable manner such as by friction fit or alternatively by the use of solder or other adhesive (not shown) .

Another embodiment of an undulating shape for the sleeve 36 is shown in Figure 4 in which a sleeve 51 has been provided of superelastic Nitinol having proximal and distal extremities 52 and 53 and having a bore 54 therein. As shown, it is provided with a single bend or undulation 56 which is arcuate in shape. This bend 56 can be formed in the same matter as hereinbefore described by utilizing a mandrel having the desired shape and then heat treating the sleeve 51 in the manner hereinbefore described to impart therein a shape memory of the desired shape of the mandrel within the sleeve. Operation and use of the guide wire 12 and the guide wire extension 13 may now be briefly described as follows. Let it be assumed that an angioplasty procedure is being performed utilizing the guide wire 12 which has been introduced into the vascular system of the patient as for example into a femoral artery by the use of a guiding catheter (not shown) . The guide wire 12 has its distal extremity advanced beyond the stenosis to be treated. A balloon catheter (not shown) which is to be utilized in the angioplasty procedure is advanced over the guide wire until the balloon is in registration with the stenosis after which the balloon can be inflated one or more times to enlarge the blood flow passage through the stenosis.

Let it be assumed that it is desired to utilize another balloon catheter which has a larger balloon thereon to increase the size of the passage through the stenosis. This necessitates an exchange cf balloon catheters. This can be readily accomplished by use of the guide wire extension 13 of the present invention and the proximal extremity 21a of the guide wire 12 which forms the male part 17. The guide wire 12 can be held by one hand while the sleeve 36 of the guide wire extension 13 is grasped by the other hand and serving as the female part 18. The male and female parts 17 and 18 are mated by pushing the male part 17 into the female part 18 to frictionally engage the same. As the sleeve 36 is receiving the part 17, the undulations in the sleeve 36 will be straightened out as shown in Figure 2 to provide the guide wire extension assembly 11 which has a generally smooth outer cylindrical surface free of undulations. Because of the shape memory characteristics of the Nitinol, the Nitinol material will remember the bends which have been placed therein and will thus increase the frictional forces between the male and female parts 17 and 18 to frictionally retain the guide wire 12 and the guide wire extension 13 in engagement with each other. The connection and separation forces for the connector assembly 16 can range from 50 to 85 grams. The frictional engagement between the male and female parts 17 and 18 should be sufficient so that balloon catheters can be inserted and removed without disturbing the connection between the guide wire 12 and the guide wire extension 13. However the frictional engagement should be that the guide wire 12 and the guide wire extension 13 can be readily connected and disconnected by human being by use of the two hands without the necessity of tools or other devices. It has been found that these frictional forces can be readily obtained even by the sleeve 51 having a single undulation or a bend therein.

As soon as the guide wire extension 13 has been connected to the guide wire 12 as hereinbefore described, the balloon catheter within the patient can be removed while leaving the guide wire in place so that the distal extremity of the guide wire 12 positioned in the stenosis will remain in place. As soon as the balloon catheter has been removed, another balloon catheter, as for example one of a larger size, can be introduced over the guide wire extension 13 and over the guide wire 12 into the desired position in the stenosis after which it can be inflated to increase the size of the opening or passageway through the stenosis. If it is desired to still utilize another larger size balloon catheter, this can be readily accomplished by removing the balloon catheter and inserting another balloon catheter over the guide wire extension 13 in the manner hereinbefore described. After the desired opening or flow passageway through the stenosis has been obtained, the balloon catheter and the guide wire extension 13 and the guide wire 12 can be removed after which the angioplasty procedure can be completed in a conventional manner. In connection with the present invention, it should be appreciated that rather than placing the undulation or bends in the female part 18, that the undulation or bends can alternatively be placed in the male part 17. Such an embodiment of the invention is shown in Figures 5 and 6. When this is the case, the core wire 61 which corresponds to the core wire 21 in the previous embodiment is formed of the Nitinol material rather than the sleeve 36 as in the previous embodiment.

Such a guide wire extension assembly is shown in Figures 5 and 6 in which the guide wire extension assembly 61 shown therein consists of a guide wire 62 and a guide wire extension 63 with a connector assembly 67 having male and female parts 67 and 68. The male part 67 is formed on the core wire 71 with at least the proximal extremity 71a being formed of the superelastic shape memory Nitinol material utilized in the sleeve 36 hereinbefore described. If desired, the entire core wire 71 can be formed of the Nitinol material or alternatively merely the proximal extremity 71a with the mandrel being formed of stainless steel and the tube materials being bonded together by a suitable material such as a weld. At least one bend or undulation is shown in Figure 5 to spaced apart bends or undulations 76 and 77 in the proximal extremity 71a. These bends 76 and 77 can be formed in a suitable matter such as hereinbefore described by the use of a cylindrical mandrel in the form of a sleeve having the desired bends or undulations therein desired to be imparted into the proximal extremity 71a. The mandrel or sleeve having such bends therein can be inserted over the proximal extremity 71a and then mounted on a suitable fixture as for example the stainless steel plate having upstanding pins in the desired pattern therein. This assembly can then be placed in an oven and heat treated in the manner hereinbefore described for the sleeve 36 at the desired temperature for a predetermined period of time after which it can be cooled in the manner hereinbefore described to impart into the proximal extremity 71a, shape memory corresponding to the shape of the sleeve mandrel. If desired, this treatment of the proximal extremity 71a of the core wire 71 can be accomplished prior to fabrication of the guide wire 62. The shape memory can be imparted into the proximal extremity 71a after the guide wire 62 has been fabricated taking care that the only proximal extremity 71a will be heated in the oven during heat treatment to impart the shape memory to the proximal extremity 71a.

When the undulations for frictional engagement being imparted into the male part 67, the female part 6C can be constructed in such a manner that the sleeve 81 forming the female part 68 and having proximal and distal extremities 82 and 83 can be formed of a suitable material such as stainless steel rather than Nitinol as hereinbefore described with the previous embodiment. It can be sized in the same manner as the sleeve 36 and can be secured to the distal extremity 31b of the extension wire 31 by suitable means such as friction fit or by a solder or weld (not shown) . The sleeve 81 is provided with a bore 84 which is sized so that it is adapted to receive frictionally the proximal extremity 71a of the guide wire 62.

In performing a medical procedure as for example an angioplasty procedure of the type hereinbefore described and an extension wire capability if desired, a guide wire extension 63 can be secured to the proximal extremity 71a by grasping the male and female parts 67 and 68 and sliding the male part 67 with the undulations therein into the bore 84 of the female part 68 to cause undulation or bends 76 and 77 in the male part to be straightened out as shown in Figure 6 and to cause frictional engagement between the male part 67 and the female part 68 to frictionally interconnect the guide wire 62 and the guide wire extension 63 into a guide wire extension assembly 61 so that catheters such as balloon catheters can be readily exchanged as hereinbefore described without danger of disconnection of the guide wire extension 63 from the guide wire 62. The guide wire extension assembly of the present invention is advantageous over extension assemblies used in the past in that the guide wire itself can be more readily manufactured because it is unnecessary to treat the proximal extremity by performing grinding operations on the proximal extremity to reduce the diameter of the same. In one embodiment of the invention, it is unnecessary to provide a bend or bends in the proximal extremity. Thus with the present invention, the proximal extremity of the guide wire can remain at the same configuration and size as the core wire utilized. This makes it possible to provide a proximal extremity for the guide wire which has a greater strength and which is less likely to be kinked by the physician handling the guide wire. Also there is less likelihood that the proximal extremity will be kinked when it is mated with the female part provided on the guide wire extension.

Although bends or undulations are provided either on the male or female part in the embodiments disclosed in the present invention, these undulations or bends are straightened out when the male and female parts are mated so that the overall outside diameter of the guide wire extension assembly does not exceed the outside diameter of the guide wire. This ensures that the catheters can be readily inserted and removed over the guide wire extension assembly.

Claims

WHAT IS CLAIMED:

1. A guide wire assembly for use in a vascular system of a patient in a medical procedure comprising a guide wire adapted to extend into the patient's vascular system, said guide wire having a proximal extremity extending out of the patient, a guide wire extension having a distal extremity, connecting means for forming a repetitive connection between the proximal extremity of the guide wire and the distal extremity of the guide wire extension, said connecting means being formed of male and female parts, at least one of said male and female parts being formed of a superelastic material.

2. An assembly as in Claim 1 wherein said part formed of a superelastic material has at least one bend formed therein formed as a shape memory in said superelastic material.

3. An assembly as in Claim 2 wherein at least two spaced-apart bends are provided in said superelastic material.

4. An assembly as in Claim 1 wherein said guide wire is provided with first and second electrical conductors and wherein said proximal extremity of said guide wire is formed of a conducting material.

5. An assembly as in Claim 1 wherein said female part is in the form of a sleeve having a bend therein.

6. An assembly as in Claim 1 wherein said male part has a bend formed therein.