Abstract:
A catheter and guide wire exchange system including a catheter having a guide wire lumen with a guide way extending along the length of a stiffened proximal shaft portion, and a guide member slidably disposed about the proximal shaft for directing a guide wire into or out of the guide way and the guide wire lumen. The proximal shaft may be slid through the guide member so that the guide wire is contained within the guide wire lumen distal to the guide member and with the guide wire and catheter being separated proximal of the guide member. The guide member has a decoupled body, that allows it to be rotated without affecting the guidewire direction through the guidemember.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to catheters used in the vascular system and more particularly to a system for facilitating exchange of such catheters and guide wires, and for using such catheters and guide wires to access selected sites within a patient.  
         BACKGROUND OF THE INVENTION  
         [0002]    Catheters are inserted to various locations within a patient for a wide variety of purposes and medical procedures. For example only, one type of catheter is used in percutaneous catheter intervention (PCI) for the treatment of a vascular constriction termed a stenosis. In this instance, the catheter has a distally mounted balloon that can be placed, in a deflated condition, within the stenosis, and then inflated to dilate the narrowed lumen of the blood vessel. Such balloon dilation therapy is generally named percutaneous transluminal angioplasty (PTA). The designation PTCA, for percutaneous transluminal coronary angioplasty, is used when the treatment is more specifically employed in vessels of the heart. PTCA is used to open coronary arteries that have been occluded by a build-up of cholesterol fats or atherosclerotic plaque. The balloon at the distal end of the catheter is inflated, causing the site of the stenosis to widen.  
           [0003]    The dilation of the occlusion, however, can form flaps, fissures and dissections, which may result in reclosure of the dilated vessel or even perforations in the vessel wall. Implantation of a stent can provide support for such flaps and dissections and thereby prevent reclosure of the vessel or provide a patch repair for a perforated vessel wall until corrective surgery can be performed. A stent is typically a cylindrically shaped device formed from wire(s) or a metal tube and is intended to act as a permanent prosthesis. A stent is deployed in a body lumen from a radially compressed configuration into a radially expanded configuration that allows it to contact and support a body lumen. A stent can be implanted during an angioplasty procedure by using a balloon catheter bearing a compressed stent that has been loaded onto the balloon. The stent radially expands as the balloon is inflated, forcing the stent into contact with the body lumen, thereby forming a supporting relationship with the lumen walls. Alternatively, self-expanding stents may be deployed with a sheath-based delivery catheter. Deployment is effected after the stent has been introduced percutaneously, transported transluminally and positioned at a desired location by the delivery catheter. In addition to angioplasty and stenting procedures, other therapeutic procedures require use of a delivery catheter, such as drug delivery, filters, occlusion devices, diagnostic devices and radiation treatment.  
           [0004]    Typically, the placement of such therapeutic delivery catheters involves the use of a guide wire, which may be inserted into the patient&#39;s vasculature through the skin, and advanced to the location of the treatment site. The delivery catheter, which has a lumen adapted to receive the guide wire, then is advanced over the guide wire. Alternatively, the guide wire and the delivery catheter may be advanced together, with the guide wire protruding from the distal end of the delivery catheter. In either case, the guide wire serves to guide the delivery catheter to the location to be treated.  
           [0005]    There are four general types of catheters: “over-the-wire” (OTW) catheters, Multi-Exchange catheters (MX) such as disclosed in U.S. Pat. No. 4,998,356 (Crittenden, et al.) and co-pending applications U.S. Ser. No. 10/116,234, Ser. No. 10/251,578, filed Sep. 20, 2003 and Ser. No. 10/251,477, filed Sep. 20, 2003, which are incorporated in their entirety herein by reference “rapid exchange” catheters and “fixed wire” or “a balloon on a wire” catheters. OTW and rapid exchange catheters require use of a guide wire separate from the catheter while a fixed wire or balloon on a wire catheter has an integral guide wire. An OTW catheter comprises a guide wire lumen that extends the entire length of the catheter. The guide wire is disposed entirely within the catheter guide wire lumen except for distal and proximal portions of the guide wire, which extend beyond the distal and proximal ends of the catheter respectively. An MX catheter has an over-the-wire configuration while the catheter is within the patient&#39;s body. Thus, the guide wire is disposed entirely within the catheter guide wire lumen, except for the distal and proximal portion of the guide wire, which extend beyond the distal and proximal ends of the catheter respectively when it is fully inserted into the patient.  
           [0006]    OTW and MX catheters have many advantages traceable to the presence of the full length guide wire lumen, such as good stiffness and pushabilty for readily advancing the catheter through the tortuous vasculature and across tight stenosis. The full-length guide wire lumen permits removal and replacement of a guide wire in an indwelling catheter, as may be required to alter the shape of the guide wire tip. It is also sometimes desirable to exchange one guide wire for another guide wire having a different stiffness. For example, a relatively soft, or flexible guide wire may prove to be suitable for guiding a PTCA catheter through a particular tortuous anatomy, whereas following up with a stent delivery catheter through the same vasculature region may require a guide wire that is relatively stiffer.  
           [0007]    Traditional over-the-wire catheters do suffer some shortcomings, however. For example, it often becomes necessary, in the performance of a PCI, to exchange one indwelling catheter for another catheter. In order to maintain a guide wire in position while withdrawing the catheter, the guide wire must be gripped at its proximal end to prevent it from being pulled out of the blood vessel with the catheter. For example, a PTCA catheter, which may typically be on the order of 135 centimeters long, is longer than the proximal portion of the standard guide wire that protrudes out of patient. Therefore, exchanging an over-the-wire PTCA catheter requires an exchange guide wire of about 300 centimeters long, whereas a standard guide wire is about 165 centimeters long.  
           [0008]    In one type of over-the-wire catheter exchange, the standard length guide wire first is removed from the lumen of the indwelling catheter. Then, the longer exchange guide wire is passed through the catheter to replace the original wire. Next, while holding the exchange guide wire by its proximal end to control its position in the patient, the catheter is withdrawn proximally from the blood vessel over the exchange guide wire. After the first catheter has been removed, the next OTW catheter is threaded onto the proximal end of the exchange guide wire and is advanced along the exchange guide wire, through the guiding catheter, and into the patient&#39;s blood vessels until the distal end of the catheter is at the desired location. The exchange guide wire may be left in place or it may be exchanged for a shorter, conventional-length guide wire. In an alternative type of catheter exchange procedure, the length of the initial guide wire may be extended by way of a guide wire extension apparatus. Regardless of which exchange process is used, the very long exchange guide wire is awkward to handle, thus requiring at least two operators to perform the procedure.  
           [0009]    A balloon catheter capable of both very fast exchange and simple guidewire and catheter exchange is particularly advantageous. A catheter designed to address this need sold by Medtronic Vascular of Santa Rosa, Calif. under the trademarks MULTI-EXCHANGE, ZIPPER MX, ZIPPER and/or MX is disclosed in U.S. Pat. No. 4,988,356 (Crittenden et al.) and pending U.S. application Ser. No. 10/116,234 filed Apr. 4, 2003; Ser. No. 10/251,578, filed Sep. 20, 2003 and Ser. No. 10/251,477, filed Sep. 20, 2003, which are incorporated in their entirety herein by reference. A MX catheter includes a catheter shaft having a cut that extends longitudinally between the proximal end and the distal end of the catheter and that extends radially from the catheter shaft outer surface to the guide wire lumen. A guide member coupled to the catheter shaft functions to temporarily open the cut such that the guide wire may extend transversely into or out of the cut at any location along its length. By moving the proximal shaft through the guide member, the effective over-the-wire length of the MX catheter is adjustable.  
           [0010]    When using the MX catheter, the guide wire is maneuvered through the patient&#39;s vascular system such that the distal end of the guide wire is positioned across the treatment site. With the guide member positioned near the distal end of the catheter, the proximal end of the guide wire is threaded into the guide wire lumen opening at the distal end of the catheter and through the guide member such that the proximal end of the guide wire protrudes out the proximal end of the guide member. By securing the guide member and the proximal end of the guide wire in a fixed position, the catheter may then be delivered over the guide wire by advancing the catheter toward the guide member. In doing so, the catheter advances through the guide member such that the guide wire lumen envelops the guide wire as the catheter is advanced into the patient&#39;s vasculature. In a PTCA embodiment, the MX catheter may be advanced over the guide wire in this manner until the distal end of the catheter having the dilatation balloon is positioned within the stenosis and essentially the entire length of the guide wire is encompassed within the guide wire lumen.  
           [0011]    Furthermore, the indwelling MX catheter may be exchanged with another catheter by reversing the operation described above. To this end, the indwelling catheter may be removed by withdrawing the proximal end of the catheter from the patient while holding the proximal end of the guide wire and the guide member in a fixed position. When the catheter has been withdrawn to the point where the distal end of the cut has reached the guide member, the distal portion of the catheter over the guide wire is of a sufficiently short length that the catheter may be drawn over the proximal end of the guide wire without releasing control of the guide wire or disturbing its position within the patient. After the catheter has been removed, another MX catheter may be threaded onto the guide wire and advanced over the guide wire in the same manner described above with regard to the MX catheter. The MX catheter not only permits catheter exchange without the use of the very long exchange guide wire and without requiring withdrawal of the initially placed guide wire, but it also overcomes many of the other difficulties discussed in association with rapid exchange catheters described below.  
           [0012]    Rapid exchange catheters developed in an attempt to eliminate the need for a guide wire extension or exchange wires. Catheters of this type are formed so that the guide wire is located outside of the catheter except for a short guide wire lumen that extends within only a comparatively short distal segment of the catheter. The rapid exchange catheter&#39;s proximal exit port for the guide wire is typically located about 5 cm (2.0 in) to 30 cm (11.8 in) proximal to the catheter&#39;s distal end. In use, the guide wire is placed initially in the patient&#39;s vascular system. The distal segment of the rapid exchange catheter then is threaded onto the wire. The catheter can be advanced alongside the guide wire with its distal segment being attached to and guided along the guide wire. The rapid exchange catheter can be removed and exchanged for another rapid exchange catheter without the use of a very long exchange guide wire and without requiring withdrawal of the initially placed guide wire.  
           [0013]    A difficulty associated with rapid exchange catheters is that it is not possible to exchange guide wires in an indwelling rapid exchange catheter, as can be done advantageously with OTW catheters. A guide wire can be withdrawn, sometimes unintentionally, from the proximal guide wire port, thus derailing an indwelling rapid exchange catheter. However, neither the first guide wire, nor a replacement guide wire, can be directed back into the catheter&#39;s proximal guide wire port, which is hidden remotely in the guiding catheter within the patient.  
           [0014]    Guide wires are commonly back loaded into the delivery catheter. In this operation, the guide wire proximal end is inserted into the distal tip of the catheter. It is pushed through the catheter until it extends out of the proximal guide wire exit. In a traditional over-the-wire catheter the proximal guide wire exit is the proximal end of the catheter through its inflation luer. The rapid exchange proximal guide wire exit is the termination of the short guide wire tube a few centimeters or typically 25 centimeters beyond the distal tip of the catheter. In the MX catheter, the proximal guide wire exit is through the guide member positioned on the proximal shaft of the catheter. As an alternative to back loading a guide wire into the delivery system, a guide wire may also be front-loaded. In a front-loading operation, the distal tip of the guide wire is inserted into the guide wire lumen on the proximal shaft and pushed through until it exits the distal tip of the delivery catheter. A front-loading operation is possible with OTW and MX catheters if the guide wire will be exchanged during procedures. A front loading operation is not used with a rapid exchange catheter since the guide wire cannot be exchanged while the catheter is inserted into the patient. With a rapid exchange catheter, the insertion of the distal tip into the proximal end of the guide wire lumen is pure chance due to the fact that the proximal end is typically 125 centimeters from the exit location of the catheter from the patient at the femoral artery in the groin.  
           [0015]    The guide member of the MX catheter is used for both advancement of the catheter into the patient and for exchanging the guide wire during the procedure without removing the catheter. In order to further optimize handling of the catheter, it is desirable to permit the user the flexibility to rotate the proximal shaft without affecting its placement with respect to the guide member and entry of the guidewire into the proximal shaft. In current MX catheters, the practitioner must ensure that the proximal shaft remains aligned with the guide member passageway. Severe torquing of the proximal shaft may result in increased force necessary to introduce the proximal shaft through the guide member passageway to engage the keel. Thus, the present invention is directed towards various embodiments of the guide member that optimize the versatility of the dual function of the guide member while permitting the user more flexibility in handling. Additionally it is desirable to decrease the profile of the MX catheter to allow for more room in guide catheter to enable more access to distal sites and allow a greater amount of dye to be flushed down the guide catheter for visualization. Thus there is a need for a smaller keel and smaller profile.  
         SUMMARY OF THE INVENTION  
         [0016]    The present invention is a guide member for an MX catheter and guide wire exchange system. The MX catheter and guide wire exchange system comprises an elongate flexible catheter having proximal and distal ends and first and second lumens extending there through. The first lumen is open at the shaft distal end and is sized and shaped to receive a guide wire. The second lumen is sized and shaped to receive inflation fluid therethrough. The catheter has a proximal shaft that may be either bitumen or tri-lumen. The distal shaft is preferably coaxial. The guide member is mounted on the catheter proximal shaft and its keel is received in a guide way formed from a longitudinal cut in a catheter proximal shaft to enable transverse access to the guide wire lumen. The guide way extends along a major portion of the length of the proximal shaft from a location adjacent to the proximal end of the catheter to a location proximal of the proximal shaft distal end. An enlarged stop is located on the exterior of the proximal shaft distal end. The guide member cannot travel distally past the stop. A balloon is mounted about catheter distal segment, with the balloon being in fluid communication with the second lumen.  
           [0017]    The guide member has a catheter passageway that extends longitudinally through the guide member and a guide wire passageway for slidably receiving a guide wire therethrough. The guide member keel cooperates with the guide way to assist in merging the guide wire into the first lumen as the catheter shaft is moved through the catheter passageway. Conversely, the guide member can be used for separating the guide wire and catheter by guiding the guide wire out of the guide wire lumen through the guide way. The guide member contains an outer member that rotates freely around the guide member positioned on the catheter shaft. Rotation of the outer member does not affect the position of the guide member keel with respect to the longitudinal cut. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:  
         [0019]    [0019]FIG. 1 is an illustration of a MX catheter and guide wire in an assembled configuration;  
         [0020]    [0020]FIG. 1A is a cross-section taken along line A-A of FIG. 1;  
         [0021]    [0021]FIG. 1B is a cross-section taken along line B-B of FIG. 1;  
         [0022]    [0022]FIG. 1C is a cross-section taken along line C-C of FIG. 1;  
         [0023]    [0023]FIG. 1D is a cross section taken along line D-D of FIG. 1;  
         [0024]    [0024]FIG. 2 is a longitudinal sectional view of a distal section of a bi-lumen proximal shaft embodiment of the present invention having an oval configuration incorporating an alternative stop embodiment;  
         [0025]    [0025]FIG. 3 is an end view of a bitumen proximal shaft embodiment of the present invention having a circular configuration  
         [0026]    [0026]FIG. 4 is an end view of a tri-lumen proximal shaft embodiment of the present invention having a triangular configuration;  
         [0027]    [0027]FIG. 5 is a perspective end view of a tri-lumen proximal shaft embodiment of the present invention having a shamrock configuration;  
         [0028]    [0028]FIG. 6 is a longitudinal cross section view of the intersection of the guide member and proximal shaft of a MX catheter;  
         [0029]    [0029]FIG. 7 is a perspective elevational view of the guide member of the present invention from the proximal end;  
         [0030]    [0030]FIG. 8 is a perspective elevational view of the guide member of the present invention from the distal end;  
         [0031]    [0031]FIG. 9 is a longitudinal cross section view of the main body of the guide member of the present invention having an alternative clipping mechanism;  
         [0032]    [0032]FIG. 10 is a perspective elevational view of the main body of the guide member of the present invention;  
         [0033]    [0033]FIG. 11 is cross section view of the main body of the present invention;  
         [0034]    [0034]FIG. 12 is a perspective elevational view of an alternative embodiment of the main body of the present invention;  
         [0035]    [0035]FIG. 13 is a perspective elevational view of the keel of the present invention; and  
         [0036]    [0036]FIG. 14 is a cross section view showing the keel engaging the proximal shaft of present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0037]    The present invention is a guide member  10  for MX catheter  12  shown in FIGS. 1 and 1A- 1 D with guide wire  14  illustrated as extending through guide member  10  and catheter  12 . Guide member  10  serves as a juncture in which the catheter  12  and guide wire  14  may be merged or separated so that the portion of guide wire  14  which extends proximally of guide member  10  (to the left as seen in FIG. 1) is separated from catheter  12  and the portion of guide wire  14  which is located distally of guide member  12  (to the right as seen in FIG. 1) is contained and housed within catheter  12  except for distal end  16  of guide wire  14  which may protrude distally out of catheter distal end  18 .  
         [0038]    Catheter  12  includes an elongate, flexible, cylindrical main body having a distal shaft  20  and a proximal shaft  22 . In the embodiment shown in FIG. 1, catheter  12  is a delivery catheter, such as for PTCA or stent delivery, having balloon  24  mounted around the catheter body near catheter distal end  18 . Balloon  24  may be inflated and deflated through inflation lumen  26  formed through the body of the catheter  12 . Inflation lumen  26  extends from the proximal end of catheter  12 , where it communicates with fitting  28  and extends the length of catheter  12 , terminating in communication with the interior of balloon  24 . Fitting  28  may be connected to a suitable source of pressurized fluid or a partial vacuum (not shown) to inflate or deflate balloon  24 . Catheter  12  includes another lumen, indicated at  30 , which is intended to receive guide wire  14 . Guide wire lumen  30  extends the full length of catheter  12 , terminating at distal end  18  and proximal fitting  28 . A longitudinal cut extends into the guidewire lumen along most of the length of proximal shaft  22  to form guideway  32 . The distal section  34  of proximal shaft does not contain guideway  32  as seen in FIGS. 1 and 1B.  
         [0039]    Proximal shaft  22  preferably contains stop  36  adjacent its distal section  34 . Stop  36  may be an enlarged section of proximal shaft  22  that prevents guide member  10  from being forced onto distal shaft  20 . Stop  36  may be annular or a series of raised areas radially spaced around proximal shaft  22 . Stop  36  may act as a wall against which guide member  10  abuts, as shown in FIG. 1, or an angled ramp  38 , as shown in FIG. 2, against which guide member  10  wedges. Lastly, as shown in FIG. 6, stop  36  may create an interference fit with docking area  42  on guide member  10 . A smaller raised area may also be located on proximal shaft  22  to act as a speed bump as shown in FIG. 2. Like stop  36 , speed bump  44  is an enlarged section of proximal shaft. However, speed bump  44  is small enough to allow proximal shaft to over ride it as proximal shaft  22  passes through guide member  10 . Speed bump  44  is spaced proximally from stop  36  such that guide member  10  is positioned between stop  36  and speed bump  44  when guide member  10  is in its most distal position on proximal shaft  22 . Speed bump  44  will advise the practitioner when stop  36  is near the guide member  10 . It also will hold guide member  10  in its distal position during a backloading operation as will be described in greater detail below.  
         [0040]    Distal shaft  20  is preferably coaxial as shown in FIGS. 1C and 1D and contains inflation lumen  26  and guide wire lumen  30 . Proximal shaft  22  may be a bi-lumen shaft or a tri-lumen shaft. Co-pending patent application titled CATHETER AND GUIDE WIRE EXCHANGE SYSTEM WITH IMPROVED PROXIMAL SHAFT AND TRANSITION SECTION and filed concurrently with this application describes various proximal shaft arrangements for MX catheters and is incorporated herein by reference in its entirety. The bitumen shaft may be oval or circular as shown by proximal shafts  46  and  48  in FIGS. 2 and 3. Proximal shafts  46  and  48  each have guidewire lumens  50  and  52  that are accessible though guideways  54  and  56  located along the proximal shaft length as in the manner shown in FIG. 1. Inflation lumen  58  of proximal shaft  46  runs side by side along the length of proximal shaft  46  with guide wire lumen  50  and is preferably supported by a stiffening member  60 , such as a hypotube. Inflation lumen  62  of shaft  42  is crescent shaped and also contains a stiffening member  64 , such as a crescent shaped hypotube. Stiffening members  60  and  64  provide stiffness for force transmission along the length of the catheter  12 . They may further include a transition section at their distal sections to ease the transition from the stiffer proximal shaft to the flexible distal shaft and avoid shaft kinking at the proximal shaft  22  and distal shaft  20  junction. For example, hypotube  60  may be skived at its distal end, with the skived portion extending into the distal section as shown in FIG. 1C.  
         [0041]    Turning now to FIGS. 4 and 5, trilumen shaft  66  may be generally circular (not shown), triangular or shamrock in its outer configuration, with the lumens preferably arranged in a triangular configuration as shown. Guide wire lumens  68  and  70  are accessible by guideways  72  and  74 . Inflation lumens  76  and  78  preferably contain stiffening members  80  and  82 , which may be hypotubes. Third lumens  84  and  86  contain stiffening wires  88  and  90 . Stiffening wires  88  and  90  preferably taper from stiffer proximal shaft  22  towards more flexible distal shaft  24 . Stiffening wires  88  and  90  preferably extend into distal shaft  20  to help transition catheter  12  from its stiffer proximal shaft  22  to its more flexible distal shaft  20 . A stiffening wire is more resistant to kinking than the hypotube. Stiffening wires  88  and  90  may freely float within their lumens, be bonded at just their proximal end, be bonded at just their distal end or be bonded at their proximal and distal ends. Use of stiffening wires allow use of a thinner and smaller diameter hypotube in the inflation lumen since the tapered wire provides the stiffness and transition previously provided by just the hypotube. Thus the inflation lumen may be optimized for inflation deflation times as opposed to accommodating the hypotube with the appropriate stiffness for the catheter. Alternatively, the third lumen may be a second inflation lumen. In such an arrangement, a second hypotube or thinner stiffening wire may be used within the second inflation lumen.  
         [0042]    Proximal shaft  22  is preferably comprised of polyethylene, but other suitable biomedical grade materials such as cross-linked PE, polyolefins, polyamides, blends of polyamides and polyolefins, fluoropolymers, polyesters, polyketones, polyimides, polysulphones, polyoxymethylens and compatibilisers based on polyolefins, included grafted polyolefins and other comparable materials may be used. A lubrication additive may also be used with any polymer and may include PE micro-powders, fluoropolymers, silicone based oils, fluoro-ether oils, molybdenum disulphide and polyethylene oxide. Additionally a reinforcing additive may be used such as nano-clays, graphite, carbon fibres, glass fibres and polymeric fibres. Distal shaft  20  is preferably made of a suitable polyethylene or polyolefin that readily bonds to proximal shaft  22 .  
         [0043]    Guide member  10  surrounds proximal shaft  22  and has proximal and distal ends  92  and  94  as shown in FIGS. 1 and 6- 12  and  14 . Guide member  10  has an outer tubular member  96  that freely rotates around inner main body  98  and hence is decoupled from the inner main body  98 . A stop consisting of an annular wall  100  extending into distal opening  102  of outer member  96  prevents main body  98  from slipping out of the outer member  96 . A retaining clip mechanism  104  is positioned on proximal portion  92  of guide member  10 . Retaining clip mechanism  104  consists of two arcuate arms  106  and  108  that form a portion of outer member wall  110  as seen in FIGS. 7 and 8. Each arm contains a tab,  112  and  114 , that extends into proximal opening  116  of outer member  96  to prevent main body  98  from slipping out of outer member proximal opening  116 . Arms  106  and  108  are opened up to remove tabs  112  and  114  from extending into proximal opening  116  to permit insertion of main body  98  during the assembly of guide member  10 . While two tabs are shown positioned 180 degrees apart, a different number of tabs may be used, provided they are spaced sufficiently to prevent main body  98  from slipping out of outer member  96 .  
         [0044]    In an alternative retaining clip arrangement as shown in FIG. 9, retaining clip  116  contains tab  118  that extends into the space designated  120  formed by inner walls  122  and  124  of main body  98 . Thus, when retaining clip  116  is in the closed position, tab  118  limits movement of main body  98  since tab  118  is captured between walls  122  and  124 . While multiple tabs may be used, only one is necessary. Outer surface  126  may have a smooth surface as shown in FIG. 9 or a textured surface such as a surface with circumferential bosses designated  128  as shown in FIGS. 6, 7 and  8 , to assist in grasping and manipulating guide member  10  as catheter shaft  22  is advanced through guide member  10 . The inner surface  130  is smooth to facilitate rotation about main body  98 . Furthermore, the materials selected may be chosen for their friction reduction and likewise a coating may be used on the inner surfaces to reduce friction.  
         [0045]    Guide member main body  98  contains catheter passageway  132  extending longitudinally in a generally straight line from guide member proximal end  92  to guide member distal end  94 . Guide wire passageway  134  extends distally from guide member end  92 , through a passageway  136 , into tube  138  and then into guide wire lumen  30 .  
         [0046]    Passageway  136  is configured to mate with a conventional wire introducer tool and further be tapered to aid in loading a conventional wire introducer tool. The length of tube  138  may vary however, it preferably extends through guide wire lumen  30  past the distal end  94  of guide member  10  as shown in FIG. 6 such that it will extend into distal shaft  20  when guide member  10  is positioned in its most distal position against stop  36 . Any suitable length may be used, but it is preferably that it extends past the junction between proximal shaft  22  and distal shaft  20  to direct guide wire through the junction. Thirty-five millimeters is one such suitable length for distal portion  140  extending past guide member distal end  94 . Apertures or cuts designated  142  may extend along the length of distal portion except for the very distal tip, such as the last 5 mm. The cuts may be a series of short cuts spaced along the length or may be a longer cut of 20-25 mm in length. Catheter passageway  132  is configured to slidingly receive the proximal shaft  22 . Its shape preferably matches the proximal shaft shape and thus for proximal shaft  46  it is oval, for proximal shaft  48  it is circular, for proximal shaft  66  it is triangular or shamrock shaped. Catheter passageway  132  enlarges in a central area designated  144  into which keel  146  and guideway closing aids  148  and  150  extend minimizing frictional forces that may be result as the guideway engages keel  146 . Catheter passageway  132  may further include docking area  42  for receiving stop  36  and shown in FIG. 6.  
         [0047]    Turning now to FIGS. 10, 11 and  12 , main body  98  is constructed from two parts, top  152  and base  154 . Top  152  houses the guidewire passageway  134  along with keel  146 , tube  138  and guideway closing aids  148  and  150 . Base  154  forms a shaft support channel  156 . Clipping mechanisms are used to secure top  152  and base  154 . A snap fit assembly is preferable for ease of assembly while still assuring top  152  and base  154  are aligned when secured. In particular, as seen in FIG. 10 clipping mechanism  158  consists of arcuate arm  160  extending from base  154  that engages arm  162  formed on top  152 . Clipping mechanism  164  operates in the same fashion with its arms  165  and  166 . Four clipping mechanism ensure a secure fit and thus additional clipping mechanisms are located opposite clipping mechanisms  158  and  164 . An alternative clipping arrangement is shown in FIG. 12. In this arrangement top  152  has arms  168 ,  170  and  172  that interlock with arms  174 ,  176  and  178  on base  154 . A fourth clipping mechanism is located opposite interlocking arms  172  and  174 .  
         [0048]    Main body  98  contains arcuate surfaces  180 ,  182 ,  184  and  186  that form rotating surfaces tangent to rotating outer member  96 . Support channel  156  formed along the bottom of catheter passageway  132  holds proximal shaft  22  under keel  146 . Outer surface  190  is also in tangential rotating contact with outer member  96 . Surface  190 , along with surfaces  180 ,  182 ,  184  and  186  are smooth to reduce any frictional forces caused by rotating outer member  96  about main body  98 . A clearance of approximately 0.05 mm exists between the rotating surfaces is preferable.  
         [0049]    Keel  146  is formed preferably as a separate component from main body  98  to allow more flexibility in the keel design. The size, shape and material of keel  146  will not be limited by the manufacture of main body  98 . Keel  146  contains an upper portion  200  that is designed to mate with slot  202  in top  152 . A positive stop, shoulder  204  surrounds upper portion  200  and mates with ledge  206  of slot  202  as shown in FIG. 11. Once mated, keel passageway  208  is in proper alignment with passageway  134  extending through top  152 . Upper portion  200  does not extend to be flush with outer surface  208  of top  152  forming recess  210 . Adhesive channels  212 ,  214  and  216  extend along the sides of upper portion  200  as shown in FIG. 13. A bore  218  extends through upper portion  200  and into passageway  208  that receives tube  138 .  
         [0050]    Keel  146  is preferably secured to top  152  with an adhesive. Keel  146  is inserted into slot  202  until shoulder  204  is firmly seated against ledge  206 . Once seated passageways  208  and  134  are aligned so that tube  140  may be inserted. Accordingly, tube  138  is inserted into passageway  208  of keel and then into passageway  134 . Passageway  134  contains a stop  220  just prior to the area  222  that receives the wire introducer tool. Tube  138  is seated in place once it abuts stop  220 . Adhesive is then placed in channels  212 ,  214  and  216  securing keel  146  to top  152 . Adhesive is also placed in bore  218  that extends down to tube  140 . Any excess adhesive will pool in recess  210  and not interfere with fitting the various components of guide member  10  together.  
         [0051]    The guide member is preferably made of Blends of Polyamides and Polyolefins—preferred, other suitable materials include Polyamides, Liquid Crystal Polymers, Lubrication additives (used in any polymer) including PE micro-powders, Fluoropolymers, silicone based oils, fluoro-ether oils, Molybdenum disulphide, and Polyethylene oxide; Reinforcing additives including nano-clays, graphite, carbon fibres, glass fibres etc., Polyesters, Polyketones, Polyimides, Polysulphones, Polyoxymethylenes, Polyolefins, Cross-linked polyolefins, Compatibilisers based on Polyolefins, including grafted Polyolefins, Ceramics and Metals, for example stainless steel.  
         [0052]    The operation of the device will now be described with reference to FIGS. 1, 2,  6  and  14 . Once guide wire  14  and guide catheter (not shown) are inserted into the patient, the catheter  12  is inserted with a backloading operation. Guidewire  14  is inserted into distal end  18  of catheter  12  and threaded proximally through guide wire lumen  30  until guide wire tube  138  captures proximal end of guidewire  14  and directs it into passageway  134  and then out of guide member  10  as shown in FIG. 1. This procedure is typically accomplished with the guide member  10  adjacent the guide way distal end. The guide member  10  may be positioned between stop  36  and speed bump  44 . This will keep guide member in proper position during the backloading operation as the force of the wire entering the guide member is insufficient to push the guide member proximally over the speed bump  44 . Likewise, if the docking arrangement is used, stop  36  will be adjacent distal end of guide member  10  and will be engaged in docking area  42  to hold guide member  10  in place during the backloading operation. As distal shaft  20  enters the patient, guide member  10  will reach the hemostatic valve (not shown). Guide member  10  is not intended to enter the valve and is seated adjacent the valve. Proximal shaft  22  is then moved though guide member  10  seated against the valve. As proximal shaft  22  is advanced, keel  146  engages guide way  32  as shown in FIG. 14. Guideway closing aids  148  and  150  located on either side of keel assist in biasing guideway  32  to its closed position. Angled edges on closing aids  148  and  150  reduce contact with guideway  32  to keep contact between guideway  32  and proximal shaft  22  at a minimum and ensure prompt closing of guideway  32 .  
         [0053]    Once inserted, the hemostatic valve may be closed down on the catheter shaft distal of guide member  10 . Since tube  138  extends into distal shaft  20  sufficiently the valve clamping forces will be felt on tube  138 . Apertures  142  on tube distal portion  140  help achieve a more effective seal around catheter shaft and guidewire  14 . If a wire change is required, one simply withdraws the guide wire  14  from the guide member  10  as it is seated against the valve and proximal shaft  22  remains in the patient. A new guide wire is then inserted into the catheter through passageway  134  on guide member. If a catheter exchange is required, one simply holds the wire in place and begins moving the proximal shaft  22  proximal though the guide member which is kept at the hemostatic valve. Once stop  36  on proximal shaft  22  is adjacent guide member  10 , the remaining portion of the catheter is removed while the guidewire is still held in place. Another catheter may then be backloaded onto the guide wire and introduced into the patient as described above.  
         [0054]    While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made there in without departing from the spirit and scope of the invention.