FR2593399A1 - DEVICE FOR EXTENDING A GUIDE WIRE USED IN CATHETERIZATION TECHNIQUES OF VESSELS, AND METHOD AND TOOL FOR ITS IMPLEMENTATION - Google Patents

Abstract

A device for extending a guide wire used in vessel catheterization techniques, and a method and tool for its implementation. System characterized in that it comprises a guide wire 12 provided with a near end and a remote end, this guide wire being longer than the catheter 10; an extension wire 24 provided with a near end and a far end; and connecting means making it possible to establish the connection between the end close to the guide wire and the end remote from the extension wire, so as to extend the effective length of the guide wire 12. The invention relates to a device for an extension of a guide wire used in vessel catheterization techniques, and a method and tool for its implementation. (CF DRAWING IN BOPI)

Description

DEVICE FOR EXTENDING A GUIDE WIRE USED IN

  TECHNIQUES OF CATHETERIZATION OF VESSELS, AND

  METHOD AND TOOL FOR ITS IMPLEMENTATION

The invention relates to

  guidewires used in catheterization processes

  vascular techniques and techniques for

kill catheter exchanges.

  In vascular catheterization procedures, it is often necessary for the physician to use different catheters for the diagnosis or treatment of a particular blood vessel. For example, when performing a coronary angiography study, the physician commonly uses a series of catheters to be introduced into the patient. Each catheter has a different shape, size or configuration

  adapted to a particular application.

  Angiographic studies typically require the use of at least three cardiac catheters including a right coronary artery catheter, a left coronary artery catheter, and a twisted catheter. The three catheters each have different shapes and configurations at their far ends. The right and left coronary artery catheters are shaped to facilitate placement of their far-out ends at the respective entrances of the right and left coronary arteries. The twisted catheter has a special twisted shape to reduce trauma when the catheter is pushed through the patient's tricuspid valve into the

  ventricle to perform ventricular studies.

  Other examples of other types of catheters may include dilatation catheters for placement in the stenotic portion of an artery and then inflating under pressure to dilate the lumen of the artery to improve the flow of blood through this artery. In some dilation processes, it may be desirable to use a series of dilatation catheters having sizes or configurations

different balloon.

  It has long been common practice, in the placement of catheters, to use a guide wire placed in the artery of the

  patient and coming to lodge in the catheter lumen.

  When a guidewire has been put in place, a catheter can be advanced on the guidewire by

  thus guiding it to the desired vascular point.

  The guidewire is used to center the catheter inside

  of the blood vessel, and to reduce the risk of

  of this blood vessel when the catheter is advanced. The use of a guidewire reduces the risk that the sliding end of the catheter will catch on the inner surface of the lumen of the blood vessel. The use of a guidewire also allows the catheter to be advanced relatively quickly into the blood vessel, reducing the

  time necessary for the implementation of the method.

  A standard guidewire is typically slightly longer than the catheter with which it is to be used. For example, for an angiographic catheter of the order of 130 cm long, the guidewire can typically be of the order of 175 cm long. When the catheter is in place on the guidewire, a relatively short portion of the guidewire protrudes from the near end of the catheter. This allows, if desired, to manipulate the

  guide wire by its projecting close end.

  In this regard, it will be appreciated that the guidewire can be embodied as a steerable construction in which a curvature is formed at the far end, and the orientation of the curvature of this end can be controlled by turn the guide wire by its near end. For example, the guidewire may be of the type described in U.S.A. Patent Application filed September 22, 1982 under nO

series 421 315.

  When it is necessary to change the catheter, it is generally preferable to withdraw the catheter in a manner that allows the guidewire to remain in place in the blood vessel so that the next catheter used in the process can be introduced. inside the blood vessel, passing it over the guide wire so that it is guided to the desired point within the blood vessel. To hold the guidewire in place, when removing the catheter, the guidewire must be blocked at its proximal end to prevent it from being removed from the blood vessel at the same time as the catheter. However, the catheter is longer than the near portion of the guide wire protruding outside the patient. Thus, before being completely withdrawn, the catheter completely covers the projecting proximal end of the guidewire. As a result, there is no way to keep a standard guidewire in place to prevent it from being removed at the same time as the catheter. If, as is often the case, it is desired to place the next catheter by advancing it over a guide wire, a new, longer guide wire must be inserted into the blood vessel and pushed into place.

  to obtain guidance of the next catheter.

  It is generally recognized that it is undesirable to introduce, advance and remove a series of guidewires into the blood vessels of a patient. Such operations greatly increase the risk of trauma and perforation for the patient, while also increasing the duration of the process. This also requires exposing the patient to additional radiation, due to the additional fluoroscopy required for

  set up the successive guide wires.

  To reduce the risk of perforation or trauma, it has become common practice for a long time

  exchange when performing catheter exchanges.

  The exchange wire is typically about 300 cm in length, i.e. much longer than a typical standard guidewire. The structure of a standard wire and an exchange wire is typically the same except for the length. The additional length of the exchange wire makes it possible to obtain, at the near end, a portion protruding a greater length than the catheter to be removed. When a catheter is withdrawn, a certain length of the portion protruding at the near end of the exchange wire remains always clear so that the exchange wire can be grasped and maintained in the blood vessel. The use of the exchange wire reduces the risk of trauma to the patient because it is placed while the first

  catheter remains in place in the patient.

  Thus, the method initially involves removing the standard guidewire from the catheter while the catheter remains in place in the patient. Next, the exchange wire is advanced into the catheter to replace the initial guidewire. Because the exchange wire is guided into the patient's blood vessel by the first catheter, this exchange wire is unlikely to come into contact with the lumen of the blood vessel except, possibly, in a small portion protruding from the blood vessel. the distant end of the first catheter. The initial catheter is then removed by sliding it over the exchange wire which remains in place in the blood vessel. The next catheter can then be inserted into the

  patient passing on the exchange wire.

  The above system and technique of using a long exchange wire have been conventional practice for many years. The use of an exchange wire during the exchange of the catheter is however not free of difficulties. The end near the exchange wire is very long and can not be handled easily if one

  wish to manipulate the distant end of the exchange wire.

  In addition, placement of the exchange wire should be done under fluoroscopy to ensure that the exchange wire is properly placed in the patient's blood vessel. The use of an exchange wire

  also increases the duration and complexity of the process.

  Despite these difficulties, the use of wire exchange has remained common practice for

catheter exchanges.

  It is an object of the invention to provide an improved guidewire system and technique for performing catheter exchange without using a separate exchange wire, and in a manner that avoids difficulties.

  and the above disadvantages of the prior art.

  To this end, the invention relates to a guidewire device for guiding an elongate and flexible catheter within a patient, characterized in that it comprises a guidewire having a proximal end and a a remote end, this guide wire being longer than the catheter; an extension wire having a near end and a far end; and link means for establishing the connection between the near end of the guide wire and the far end of the extension wire, so as to extend the length

effective guide wire.

  The invention thus makes it possible to perform a catheter exchange without requiring any exchange of guidewires. According to the invention, the guide wire extension is attached to the near end of the guide wire while the guide wire remains in place in the patient. The guidewire extension effectively increases the length of the guidewire. When the extension is attached to the guide wire, the catheter can be removed by sliding on the guidewire and its extension. The increase in length makes it possible at all times to release the near end of the combined assembly of the guidewire and its extension, so that its position can be maintained during the extraction of the catheter. When the first catheter has been removed, the new catheter can be inserted on the combined guidewire assembly

and its extension.

  This technique considerably reduces the process time because the extension can be attached to the near end of the guide wire much faster than the operation of performing a guide wire exchange.

  classic. In addition, an additional reduction

  avoid the risk of perforation of the blood vessel.

  In addition, exposure to fluoroscopic radiation is less important than the exposure required to predict

  each time a guidewire is introduced.

According to the invention, the

  The proximal thread of the guide wire includes a connector device which may be in the form of a tubular socket. The socket allows to receive a corresponding tip formed at the far end of the extension wire. When the extension wire and the guide wire are nested, the seal is fixed, for example by crimping by means of a special crimping tool. In the preferred embodiment, the crimp is trapezoidal in shape and has a low profile so as not to hinder the advancement of the catheters on the crimped seal. When successful catheter exchange, the joint can be broken to separate the extension and allow manipulation

  Easy guide wire by its near end.

  The invention thus makes it possible to obtain a new and improved technique for

  perform the exchange of catheters.

The invention also

  to create a guide wire system

  kill the exchange of catheters without the use of a

exchange wire.

  The invention still makes it possible to create a rapid catheter exchange technique

  not requiring fluoroscopic exposure.

The invention still allows

  to create a process and apparatus to fix a

  long on the near end of the guidewire while keeping this guidewire in place, thereby facilitating the exchange of catheters

  on the combination of guidewire and extension.

  The invention finally makes it possible to create a device in which the extension wire can be separated from the guide wire after having been carried out.

catheter exchange.

  The invention will be described in detail with reference to the accompanying drawings in which: - Figure 1 is a schematic representation of a patient on which

  performs a catheterization by introducing a catheter-

  percutaneously in the femoral artery, the figure schematically showing the catheter and the guide wire protruding at the near end, and also showing, in broken lines, the relative length of an exchange wire; FIG. 2 is a fragmented and partially sectional composite representation, without scale, of the end near a conventional length guide wire according to the invention and of the extension of this guide wire, the FIG. away from the extension aligned with the near end of the guide wire ready to be nested; - Figure 3 is a scale-less representation of the near and far ends of the guide wire and the extension wire according to the invention, these ends being nested but not yet crimped; - Figure 4 is a scale-less representation of the crimped connection of the guide wire to the extension wire; - Figure 5 is a partially fragmented representation and partially in section, the crimping tool; Figure 6 is a side elevational view of the jaw end of the crimping tool with the jaws in a locked position on a wire; Fig. 7 is a sectional view taken along the line 7-7 of Fig. 6, showing the jaws blocking the near end of the guide wire ready to receive the guide wire extension; - Figure 8 is a representation similar to that of Figure 7, wherein the extension wire and the guide wire are connected to each other, the jaws of the crimping tool being in crimping position; and FIG. 9 is a side view, in elevation, of the jaws of the crimping tool in crimping position, the view being

  performed along the line 9-9 of Figure 8.

  FIG. 1 represents, in very schematic form, the catheter 10 and the guidewire 12 which were introduced into the femoral artery of the patient and were pushed into the patient's heart zone, where the desired method must be implemented. The guidewire 12 and the catheter 10 have been introduced and placed in the artery according to

well known conventional processes.

  When it is desired to exchange the catheter for replacement with another, it is important that the guidewire be held within the patient's artery so that it can quickly and effectively guide the next catheter to desired point of the vascular system of the patient. Typically, the clearances between the guidewire 12 and the inner lumen of the catheter 10, associated with the curvatures that the catheter and the guidewire 12 must follow along the patient's vasculature, are such that the extraction of the catheter 10 tends to occur. to drive the guide wire 12

  to get it out with the catheter 10.

  To hold the guidewire 12 in place when removing the catheter 10, it is necessary to hold the guide wire 12 by its near end 16 while the catheter 10 is being withdrawn by sliding it on the guidewire 12 Since the proximal end 16 of a conventional guidewire protrudes from the proximal end 18 of the catheter only by a length substantially less than that of the catheter 10, there is no means for retaining the guidewire. classic 12 in place while we

remove the catheter 10.

  To perform a catheter exchange, it has been common practice for many years to use a wire exchange. The exchange wire is significantly longer than the conventional guide wire 12 and may have a length of the order of 300 cm. The additional effective length of the exchange wire, as compared to the length of a conventional guidewire 12, is represented by the dashed line 20 of FIG. 1. The length of the exchange wire is such that its end, represented by the reference 22, is separated from the proximal end 18 of the catheter by a distance greater than the length

of the catheter 10.

  When exchanging, the guidewire 12 is withdrawn from the catheter 10 while the catheter remains in place in the patient. The exchange wire is introduced and then advanced along the catheter 10 until its far end reaches the point within the vascular system of the patient. The additional length of the exchange wire protruding from the proximal end 18 of the catheter 10 provides a means of sufficient length to be able to catch the exchange wire so as to hold it in place in the patient while removes the catheter 10. Thus, the catheter 10 can be removed by passing over the exchange wire, and the following catheter can be placed in the patient by advancing it on the exchange wire along the same . When the new catheter has been put in place, it may be desirable to remove the exchange wire

  and replace it with another long-term guide wire

  standard, depending on the type of catheter

  to carry out. For example, if the process requires the use of a steerable guidewire to be handled by its near end, this guidewire must be replaced by the exchange wire.

  after the catheter exchange has been performed.

  According to the invention, the catheters can be exchanged without the need to remove the guide wire 12 and without the need to implement the complications associated with the use of an exchange wire. According to the invention, the guidewire 12 is connected by its proximal end to an extension wire 24 while the guide wire 12 and the catheter 10 remain inside the patient. The extension wire 24 is securely attached to the near end of the guide wire 12 and serves to sufficiently extend the effective length of the guidewire 12 so that the catheter 10 can be removed by passing it through

  the guide wire 12 and on the extension 24. -

  As shown in Fig. 2, the guidewire 12 is provided with a hollow tubular branch fitting 26 which is fixed and projecting at the near end of the guidewire 12. In the embodiment illustrated here, the thread Guide 12 has a close end consisting of a solid wire such as the guide wire of the type shown in U.S. Patent Application Serial No. 421,315, supra. However, it is obvious that the general principles of the invention can be applied to any guide wire by modifying the end near this guide wire so that it comprises means for fixing the end near the guide wire. wire of

guidance to an extension wire.

  In the embodiment illustrated here, the end near the guide wire is provided with a projection of reduced diameter 28 which is housed in one end of the tube forming the connection fitting 26. The tube 26 is fixed to the wire of guide 12, for example by brazing as indicated at 30, at the junction of the end of the tube 26 with the shoulder

  32 formed at the point of transition between -

  guidewire 12 and the reduced diameter projection 28. An alternative construction may use a tapered portion to form the transition between the guidewire and the projection 28. The outer diameter of the tube 26 is preferably the same as the outer diameter The tube 26 thus forms an elongate socket 34 for receiving, as described hereinafter, the remote end of the extension wire 24. The tube 26 may be made of stainless steel, as may the wire The tube 26 may be made from a readily available hypodermic pipe. The wall thickness of the tube 26 should be chosen so that it can be crimped easily, as described below, but also so that it is able to provide sufficient rigidity to maintain a solid connection with the extension.

of guidewire 24.

  By way of example of dimensions, for a guidewire of the type described in US Patent Application Serial No. 421,315 above, the proximal end of the guidewire may have an outer diameter of the order of 0.4 mm,

  and the pipe 26 must have the same outside diameter.

  A wall thickness of the pipe of the order of 0.038 mm to 0.076 mm was satisfactory. The length of the tube 26 may be of the order of 10 cm and the depth

  of the socket may be of the order of 7.6 cm.

  The guide wire extension 24 can also be made of stainless steel, and its diameter should preferably be compatible

  with that of the guide wire 12 and the extension 26.

  The remote end of the extension 24 has a reduced diameter end 36 intended to be introduced into the socket 34 of the adapter 26. The guide wire extension 24 may have a conical transition zone 38 between its main body and its end 36. As an example of dimensions in the embodiment illustrated here, the end 36 may have a length of about 4 cm and an outer diameter of about 0.2 to 0.23 mm so The end 36 and the bushing 34 must be sufficiently long for the entire length of the end 36 to penetrate into the bushing 34. FIG.

  way in which the guidewire 12 and the prolongation

  guide wire 24 fit together. The remote end of the extension is simply inserted into the bushing 34 of the adapter 26. The elements thus connected are then deformed, preferably in the configuration shown in FIG. 4, to fasten together the wire 12 and the extension 24. After fixation, the effective length of the wire 12 has been prolonged and the catheter 10 can be removed by passing over the combined length thus prolonged, without

  it is necessary to remove the guide wire 12.

Mechanical fixation is

  obtained preferably by deforming the tube 26 and the ex-

  tremité 36 connected together, by displacement of a segment of these elements in the lateral direction relative to the common axis X of the combination of the guide wire 12 and the extension 24. The amplitude of the lateral displacement is however limited by the flexibility of

  catheters with which the device is to be used.

  The amplitude of the lateral displacement must not be too great or too brutal not to cause a sudden curvature of the catheter may hinder the progressive advancement of the catheter 10 on the seal. According to the invention, it has been found that trapezoidal deformation seems to give the best results, although other non-trapezoidal shapes may

to be used.

  As shown in FIG. 4, the preferred embodiment of the crimping is generally U-shaped and comprises a trapezoidal central segment 40 and a pair of spaced segments 42, with an inclination angle of about 30 with respect to central axis of the guidewire, formed between the ends of the tube 26. Preferably, the crimping is done in a manner leaving a short close segment 44 of the tube 26 remaining in coaxial alignment with the extension wire 24. In the preferred form embodiment, the spaced segments 42 are arranged at an angle A of about 30 relative to the central axis of the guide wire 12 and the extension

  24. The crimped central segment 42 is displaced transversely

  the X axis but is located substantially parallel thereto. Preferably, the central segment 40 may be offset by about 1.52 mm with respect to the common axis X. The total length of the crimping comprising the end segments 42 and

  the central segments, is of the order of 15, 24 mm.

It has been found that such

  liaison could be achieved quickly and easily.

  This bond maintains a sufficient tensile strength, of the order of 0.45 kg to 0.9 kg so as not to separate during use, while not jeopardizing the advancement of the catheter when it just slip on the crimped part. In addition, it will be noted that the connection also maintains a resistance of the order of 0.45 to 0.9 Kg in sufficient compression so that when the catheter advances on the guide wire and on the extension, the connection between the wire guide and guidewire extension does not sag or deform in any other way under the action of compressive force resulting from catheter thrust along the extension

guide wire.

  In addition, the connection can be broken easily and quickly if desired, to separate the guide wire extension 24 from the guide wire 12. The guide wire 12, the adapter 26 and the guide wire extension 24 are preferably all coated with a thin film of anti-friction material such as polytetrafluoroethylene to facilitate sliding of the catheter over the guidewire and over the

extension connected to it.

  Although the principles of the invention can be applied to a wide variety of guidewire and catheter sizes, the configuration of the embodiment illustrated here is very convenient, particularly for small diameter guidewires. intended for use with flexible catheters of relatively small diameters. For example, the form

  6 of embodiment of the invention shown here is parti-

  particularly interesting when using guide wires of the order of 0.63 mm diameter or less, these guide wires being in turn used with

  catheters of the order of 6 French Units or less.

The invention also relates to

  a device intended to facilitate the connection and the

  Said guide wire 12 connected to the extension wire 24. As indicated in FIGS. 5 to 9, the crimping device generally indicated by the reference numeral 50 may be molded in a suitable plastic material such as, for example, Delrin (trademark of the acetal). The crimping device 50

  is substantially in the form of tongs comprising

  both a pair of handle members 52, 54 connected to each other by a pivot rod 56, and a slot 58 integral with the elements 52, 54. The elements 52, 54 can thus pivot one to the other. relative to one another, forming a pair of jaw members 60, 62 which can move closer and apart from each other. The jaws 60, 62 are arranged to: maintain the linkage 26 at the end near the guidewire 12, in a position to receive the end 36 of the extension wire 24. The jaws 62 comprise also a device for guiding the end 56 of the extension wire 24 in the socket 34 of the adapter 26, this device also making it possible to perform the crimping illustrated in FIG. 4 when the extension wire and the adaptation

26 are nested.

  One of the jaw members has an inner face 64. The jaw 60 is molded to include a platform 66 extending from the jaw face 64. The platform is of trapezoidal configuration and includes an upper face 68 parallel to the inner face. 64 of the jaw 60, and a pair of inclined side faces 70. A transverse groove 72 is formed transversely along the upper face 68 of the platform 66. The groove 72 is intended to receive, and maintain the adaptation of 26. The opposing jaw 62 has a trapezoidal cut 74 having

  corresponding surfaces parallel to those of -

  platform 66, including surfaces 70 and 72.

  The jaw member 62 also includes a pair of transverse members 76, 78 having surfaces 80, 82. The surfaces 82 are parallel to the surface 64 of the member 52 when the jaws 60, 62 are coupled. As will be described in more detail below, the adapter 26 can be put into place in the device by placing it along the passage 72 and closing the jaw 62 so that the jaw surfaces 80 and 82 come into position. engage against the adapter 26 to hold it in place ready to receive the end 36 of the extension wire 24. The surface 82 of the jaw member 62 is provided with a transverse groove 84 receiving the end of the adapter 26 in a manner and for a purpose to be described below. The outer end of the groove 84 is formed to have a funnel-shaped passage 86 diverging

  upwards and in the transverse direction.

  The jaw end of the handle member 52 includes an elongated finger 88 integral therewith and separated from the portion

  main part of the jaw member 60 by a slot 90.

  The finger is formed so as to bend and bend relative to the memory 60 and the handle 52. The outer end of the finger 88 is formed to include a platform 92 having an upper surface 94. The platform 92 comprises a transverse groove 96 communicating with a passage

  funnel-shaped 98 opening transversely.

  The platform 92 is placed relative to the transverse portion 78 of the jaw 62 so that when the jaws 60, 62 are brought closer to each other, the surfaces 82 and 94 abut one against the other, the grooves 84, 96 cooperating to form a guide passage, and the passages e6, 98 cooperating to form a

  funnel terminating in the guide passage.

  As indicated in FIGS. 6 and 7, the link adaptation 26 is maintained between the jaws 60, 62 so that this adaptation 26 comes into contact with the passage 72 of the platform 66 and with the surfaces 80 and the groove 84. The adapter 26 is thus securely held in place and its bushing 34 is aligned with the guiding passage formed by the cooperating grooves 84, 96. The remote end 36 can then be passed through. extension wire 24 in the funnel 86 to penetrate the aligned sleeve 34. The funnel formed by the passages 86, 98 serves to facilitate entry

  end 36 in the socket 34.

  When the remote end 36 of the extension wire has been introduced, through the funnel and the guide passage, into the sleeve 34, the crimping tool is actuated to close the jaws 60, 62 and perform the crimping operation. . During the crimping operation, the finger 88 bends down as

  indicated in Figure 7 so as to maintain the alignment

  axial direction of the guide wire 12 and the extension wire 24 located in the near and remote positions of the crimping. When the crimping is completed, the jaws 60, 62 are opened to release the wires 12, 24 connected to each other. The guidewire 12 has thus been effectively extended so that it can be removed.

  the guide wire 12 and introduce a new exchange wire.

  When the extension has been secured and the catheter removed, the next catheter, the extension and the guide wire, are advanced into the blood vessel.

  of the patient.-Depending on the technique used and the preferences

  doctor can be left attached to or easily separated from the guidewire. Separation can be done by cutting

  the guide wire at a distance from the crimping.

  It will be appreciated from the foregoing that the invention provides a technique and device for performing catheter exchanges in a manner that shortens the time required to implement the method, reducing the exposure time of the catheter. radiation, and further reducing the risk of trauma to the patient.

Claims (19)

  A guidewire device for guiding an elongate and flexible catheter within a patient, characterized in that it comprises a guidewire (12) having a near end and a far end. this guidewire being longer than the catheter (10); an extension wire (24) having a near end and a far end; and connecting means for establishing the connection between the proone end of the guide wire and the far end of the extension wire, so as to extend the effective length of the guide wire (12). 2- guide wire device according to claim 1, characterized in that the combined length of the guide wire (12) and the wire of. extension (24) is approximately double the length of the catheter.   3- guide wire device according to claim 1, characterized in that the connecting means are constituted by means for performing a mechanical engagement between the end near the guide wire (12) and the end   away from the extension wire (24).   The guide wire device according to claim 3, further characterized in that the mechanical engagement is constructed and arranged to have sufficient voltage resistance to withstand a separating force. axial of the order of 0.45 kg.   - Guide wire device according to claim 3, characterized in that the mechanical engagement is constituted by a crimped engagement. The guide wire device according to claim 3, further characterized by the fact that the mechanical engagement is constructed; and arranged to have sufficient compressive strength to withstand axial load of the order 0.45 kg.   The guidewire device according to claim 4, further characterized in that the mechanical engagement is constructed and arranged to have sufficient compressive strength to support an axial load of the order 0.45 kg.   8. A guidewire device according to claim 3, characterized in that the mechanical engagement further comprises a tubular sleeve (34) formed at the end near the guide wire, the other end of the extension wire (24). ) being dimensioned so as to be housed in the tubular sleeve (24); this end and the tubular sleeve thus nested being designed to deform transversely in a generally U-shaped configuration. 9- Guide wire device according to claim 8, characterized in that the tubular sleeve (34) is formed at end near the guide wire, and in that the far end of the guide wire is dimensioned so as to   come and stay in this double tubular.   A guidewire device according to claim 9, characterized in that the U-shaped configuration comprises a generally trapezoidal shaped portion having a central segment (40) and a pair of end segments. inclined (42).   A guidewire device according to claim 10, characterized in that the inclined segments (42) have an inclination angle of about 30 with respect to the central axis of the guide wire and the extension wire. 12- A guidewire device according to claim 10, characterized in that the central segment (40) is offset with respect to the axis of the guidewire device by a sufficient amount to hold the guidewire together ( 12) and the extension wire (24) when subjected to force at least 0.45 kg.   13- A guide wire device according to claim 12, characterized in that the central segment (40) is offset by about 1.52 mm   relative to the axis of the guidewire system.   14- A guidewire device according to claim 13, characterized in that   the total length of the crimp is about 15.24 mm.   A guidewire device according to claim 9, further characterized in that the far end of the extension wire (24) is tapered and terminates in an elongated end of substantially uniform diameter for housing.   in the tubular sleeve (34) of the guidewire.   16. A guidewire device according to claim 15, characterized in that   the extension wire (24) is a solid rod.   The guidewire device of claim 9, further characterized in that it comprises a tubular member attached to the proximal end of the guidewire, said tubular member defining a deep socket for receiving the far end of the guidewire. extension wire (12).   The guidewire device of claim 17, further characterized in that the guidewire sleeve is in the form of a thin-walled tube of the order of 10 cm in length, having a thickness wall thickness between about 0.038 and 0.076 mm, the socket   of the tube having a depth of the order of 7.6 cm.   19. The guidewire device as claimed in claim 18, characterized in that the means of elision comprise an elongated tube attached to the end near the wire-shaped element, the tube being intended to receive the other wire, this tube being constructed and arranged to contain the other yarn, the tube and the other yarn being crimpable in a manner to achieve mechanical engagement between the two.   - Method for implementing the device for performing a catheter exchange using a guidewire system according to   any one of claims 1 to 19,   characterized by using a guidewire (12) having a near end (16) and a far end; using a first catheter having a near end and a far end, said first catheter being shorter than the guide wire; placing the guidewire (12) within a blood vessel of a patient so that the proximal end of the guidewire protrudes from the patient's textured; placing the first catheter in a blood vessel of the patient by passing it over the guidewire so that the end of the catheter protrudes out of the patient, and the proximal end of the guide wire protrudes near the proximal end of the catheter; attaching an extension wire (24) to the near end of the guidewire (12); drawing the first catheter through the proximal end by passing it over the guide wire (12) and the extension wire (24) while holding either the guide wire or the extension wire to hold the guidewire in place in the patient's blood vessel so as to remove the first catheter from the patient's blood vessel; placing a second catheter on the proximal end of the exchange wire and advancing the second catheter over the extension wire and over the guidewire into the patient's blood vessel, thereby permitting to perform catheter exchange without   it is necessary to remove the guide wire.   The method of claim 20 further characterized in that it further comprises separating the extension wire (24) guide wire (12).   22- The method of claim 20, characterized in that the step of connecting the extension wire to the guide wire is to use a tubular sleeve (34) placed on the guide wire and to introduce an end of the extension wire, in the socket; then mechanically crimp both parts together nested. 23- Tool for setting   process according to any of the claims   20 to 22, so as to crimp a first wire having a tubular sleeve (34) at one end and a second wire housed in this socket, characterized in that it comprises a pair of jaws (60, 62 ) mounted so as to get closer and move away from each other; these jaws having opposed surfaces shaped to cooperate to perform crimping on an element placed between the jaws when these jaws abut against each other; the jaws having a first position in which they are only clamped to adequately hold a thin tubular member in a substantially straight configuration; the jaws further carrying guide means for aligning and guiding a wire in an open end of the socket of the tubular member, thereby to associate the wire and the socket; and the jaws having a second position in which they are tightened to crimp the combined assembly of the tubular sleeve and the end of the wire,   to mechanically fix the wire to the tube. 24- Tool according to the claim   cation 23, characterized in that the crimping presents   a substantially trapezoidal shape. - Tool according to the   cation 24, further characterized in that a first   jaw presents a platform defining a confi-   gure trapezoidal general shape; the other jaw having a trapezoidal cutout intended to coincide exactly with the trapezoidal platform; in that a transverse groove is formed on the platform to partially receive the tubular element; in that   the other of the jaws has a pair of spa-   transversely, intended to come into contact with the tubular element; and in that the alignment means comprises guide passage forming means on each of the jaws, so as to form a wire passage when the jaws are in the first position, this wire passage being aligned with the transverse groove when the jaws are in the first position.   26- Tool according to claim 25, characterized in that the alignment means are designed and arranged to move in synchronism with the second of the jaws during the movement of the jaws between the first and the second positions.