Patent Publication Number: US-2007123826-A1

Title: Guide wire torque device

Description:
CROSS REFERENCE TO RELATED APPLICATION  
      This application claims the benefit of U.S. Utility application Ser. No. 10/444,773, filed May 24, 2003, the contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION  
      This invention relates to a device for gripping a guide wire in a manner such that torque and/or force can be applied to the guide wire to direct it during a medical procedure.  
     BACKGROUND OF THE INVENTION  
      Certain medical procedures include the use of a guide wire that is passed through one or more tubular vessels in the body, such as blood vessels. Among these procedures are (a) percutaneous transluminal coronary angioplasty (PCTA), wherein a balloon catheter is steered through a blood vessel to a given location and inflated in order to dilate a coronary artery, (b) stent or stent graft insertion, (c) blood vessel stripping, (d) blood vessel harvesting, (e) angiography, and (f) percutaneous transluminal angioplasty.  
      For procedures involving a blood vessel the guide wire is typically introduced into a vessel via an opening made by a surgeon. For example, a guide wire may be introduced through a small needle hole made in the femoral artery in the groin area. The guide wire may then be maneuvered through the femoral artery and aorta and into branches of the vascular system until it reaches the desired location in the desired vessel. Maneuvering the guide wire requires the surgeon to apply torque to the end of the wire outside of the body (the “proximal end”) to twist or rotate the wire, thereby changing the position of the end of the wire inside the body (the “distal end”) to guide it into openings to branch vessels.  
      Guide wires often have a slippery, hydrophilic coating to provide high lubricity thus allowing the wire to pass easily through an organ, such as a blood vessel. However, such guide wires may be so slippery that sufficient torque cannot be applied by simply rolling or twisting the proximal end of the guide wire between a thumb and forefinger. Consequently, a torque device is needed to grip the guide. wire for adequate torque to be applied.  
      Traditional torque devices are comprised of a small tube, or body portion, having an opening therethrough. At one end of the tube is a structure, such as a collet having four fingers that can be pressed together, to grip the guide wire. A screw cap having a hole for the passage of the guide wire therethrough is secured to the tube, is positioned over the collet and has a tightened position and a loosened position. As the cap is moved to the tightened position, the fingers are compressed radially inward, gripping the guide wire positioned between them. The guide wire can then be manipulated by turning or twisting the torque device.  
      A drawback of known torque devices is that the guide wire can only be threaded from one end, i.e., through the cap positioned at one end of the torque device, which may make the device difficult to thread in the operating room. Additionally, known torque devices grip a guide wire at just one location, which does not always sufficiently secure the guide wire to allow the application of adequate torque and/or force for steering or to pull the guide wire taut during certain procedures, such as vein harvesting (during which, additional longitudinal displacement forces may be encountered). Additionally, with known torque devices the guide wire must be advanced or retracted by holding the guide wire in one hand, which can be awkward.  
      In addition, guide wires are packaged for shipping. A commonly-used guide wire package is a tubular plastic sheath into which the guide wire is placed. Typically, when packaged, an end of the guide wire extends outside of an end of the package and a guide wire director is positioned on the exposed end of the guide wire. The guide wire director has a first end that includes an opening dimensioned to receive the end of the guide wire package, thus securing the director and guide wire during shipping and handling, and a second end that includes an elongated snout, which is used to introduce the guide wire into a lumen, such as the lumen of a vein or catheter. It would be advantageous to provide a torque device that could be preapplied to the guide wire (rather than being applied in the operating room) and that could be positioned on an end of a guide wire package so it remained positioned thereon during shipping. It would also be advantageous if a torque device included a snout to assist in introducing a guide wire into a lumen.  
     SUMMARY OF THE INVENTION  
      One device according to the invention is a guide wire torque device for gripping a guide wire at more than one location on the wire. The torque device has an opening extending therethrough, an open position and a closed position. When the torque device is in the open position the guide wire may be passed through the opening. When the device is in the closed position the guide wire is gripped at more than one location thereby allowing torque and/or force to be applied to the guide wire.  
      One preferred embodiment of the torque device described above includes a body portion, a first cap secured to a first end of the body portion and a second cap secured to a second end of the body portion. The opening extends through the body portion. A first collet is formed at the first end of the body portion and a second collet is formed at the second end of the body portion. Each collet includes a plurality of compressable fingers for gripping a guide wire, however, any structure(s) for gripping a guide wire may be used. The first cap engages the first collet and may be tightened to the first end of the body portion, preferably by utilizing a threaded connection. When tightened, the first cap compresses the fingers of the first collet so that the fingers grip the guide wire. The second cap engages the second collet and may be tightened to the second end of the body portion, also preferably by utilizing a threaded connection. When tightened, the second cap compresses the fingers of the second collet so the fingers of the second collet grip the guide wire.  
      An alternate torque device according to the invention includes an elongated snout (or simply “snout”), to assist in straightening and/or guiding a guide wire, such as an angled or J-tipped guide wire, into a lumen, such as the lumen of a vein or a cannula, and thus acting as a guide wire director. Such a device is configured to grip a guide wire at one or more locations when in the closed position.  
      Another torque device according to the invention is configured to receive the end of a guide wire package. Such a torque device is preferably mounted to a guide wire extending outside the end of the package and the torque device is positioned so that the end of the guide wire package is received in an opening in the torque device. This secures the torque device to the guide wire package during shipping to help protect the guide wire and the torque device. Such a torque device is configured to grip a guide wire at one or more locations when in the closed position.  
      A torque device according to the invention may also include a structure for securing a body member (such as a blood vessel) or other object to the device, the structure preferably being an annular bump or ridge, wherein the ridge is preferably positioned on an elongated snout of the device.  
      Another torque device according to the invention includes a mechanism, such as a thumb wheel, for advancing or retracting a guide wire. Such a device may further include an elongated snout, a structure for securing a body member or other object thereto, and grips a guide wire at one or more locations when in the closed position. In this embodiment the guide wire may be gripped solely by the mechanism or by the mechanism and other structures on the device.  
      Another device according to the invention includes an opening in the body portion of the device that exposes a guide wire contained therein. The exposed guide wire can then be advanced or retracted utilizing one&#39;s finger or thumb. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      A detailed description of the invention will be made with reference to the accompanying drawings wherein:  
       FIG. 1  is a peripheral, exploded view of a preferred embodiment of one aspect of the present invention.  
       FIG. 2  is a side view of the device shown in  FIG. 1  with the components assembled.  
       FIG. 3  is a cross-sectional view of the device shown in  FIG. 2 .  
       FIG. 4  is a side view of an alternate cap that may be used with a device according to the invention wherein the cap includes a snout and a structure for securing a body member or other object thereto.  
       FIG. 4A  is a cross-sectional view of the cap shown in  FIG. 4 .  
       FIG. 5  is a side view of another alternate cap to be used with a device according to the invention wherein the cap includes a structure for securing a body member or other object thereto.  
       FIG. 5A  is a cross-sectional view of the cap shown in  FIG. 5 .  
       FIG. 6  is a side view of another alternate cap to be used with a device according to the invention wherein the cap includes a snout and an alternate structure for securing a body member or other object thereto.  
       FIG. 6A  is a cross-sectional view of the cap shown in  FIG. 6 .  
       FIG. 7  is a side view of another alternate cap that may be used with a device according to the invention, wherein the cap has an opening dimensioned to receive a guide wire package.  
       FIG. 7A  is a cross-sectional view of the cap shown in  FIG. 7 .  
       FIG. 8  is a top view of an alternate device according to the invention, wherein the device includes a mechanism for advancing or retracting a guide wire.  
       FIG. 9  is a cross-sectional view of the device of  FIG. 8 .  
       FIG. 10  is an end view of the device of  FIG. 8 .  
       FIG. 11  is a side view of an alternate device according to the invention. 
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT  
      Turning now to the drawing where the purpose is to describe preferred embodiments of the invention and not to limit same, a preferred embodiment of one aspect of the invention is device  100 , illustrated in  FIGS. 1-3 . Device  100  is for gripping a guide wire (not shown) used in medical procedures and for allowing a user (typically a surgeon, cardiologist or radiologist) to provide torque and/or force to the guide wire. Device  100  is preferably comprised of plastic such as polypropylene or acetal (including AMILUS acetal, supplied by Southland Polymers Inc., 14030 Gannet St., Santa Fe Springs, Calif. 90670) or other suitable plastic or other material and preferably has a maximum width W of 9 mm or less.  
      Device  100  comprises a body portion  102  preferably comprised of a first section  102 A and a second section  102 B that snap fit or pressure fit together, although any method of attachment may be used. Body portion  102  could be comprised of a single section or any number of sections; the preferred embodiment of body portion  102  includes two sections for ease of manufacturing. In the preferred embodiment, section  102 A has a length of about 27 mm and section  102 B has a length of about 34 mm, although any suitably-sized body portion and/or body potion sections may be used.  
      Body portion  102  may include one or more handling surfaces  102 C. Each handling surface  102 C assists in the handling and manipulation of device  100  and may be a raised section on body portion  102 , a series of grooves or depressions formed in body portion  102  or any structure formed on body portion  102  that allows for easier handling and manipulation by a user.  
      Body portion  102  includes a first end  104  that has a collet  106  and a threaded portion  108 . Body portion  102  also includes a second end  110  that has a collet  112  and a threaded portion  114 . Each collet  106 ,  112  includes multiple (four are shown in the drawing) longitudinally-extending and substantially parallel projections or fingers  116 . In the preferred embodiment, each of fingers  116  has a cross-section approximately resembling ¼ of a circle. Although the preferred embodiment shows fingers, any structure(s) on the torque device suitable for performing the gripping function may be used. Further, if fingers are used to grip the guide wire, any number of fingers of any shape can be employed as long as they can grip a guide wire when compressed.  
      As shown in  FIG. 3 , on opening  120  is defined through body portion  102 , and opening  120  comprises interconnected openings  122 ,  124 ,  126 ,  128 ,  130 ,  206  and  134 . Opening  120  is designed to be sufficiently large enough to allow the guide wire (a typical guide wire has a diameter of between 0.010 to 0.038 inches) used with device  100  to be inserted through device  100  when device  100  is in the open position (as described below) and the width or diameter of opening  120  may vary along its length. Openings  126 ,  130  in collets  106 ,  112 , respectively, are preferably substantially the same size. As used herein, substantially the same size means that the collets (or any gripping structure(s) used to practice the invention) have openings and appropriate structure such that they each grip the same guide wire when compressed. In one preferred embodiment each collet  106 ,  112  has an outside diameter of 4.75 mm and openings  126 ,  130  each have a diameter of 0.94 mm when fully open (i.e., when not compressed), although the invention is not limited to these dimensions and an opening through which the guide wire passes need not be cylindrical.  
      In the embodiment shown, body portion  102  includes a projection  129  and a cavity  132 . Projection  129  is received in cavity  132 , preferably in a snap-fit manner, to connect sections  102 A and  102 B.  
      Device  100  also includes a first cap  200  and a second cap  202  that are each preferably secured to body portion  102  to allow for easier handling of device  100  than having the caps completely separate from the body portion, in which case device  100  would comprise multiple, loose pieces. (However, one or more caps used with a device according to the invention could not be secured to the body portion.) Cap  200  is secured to body portion  102  via any suitable means, such as an ultrasonic weld, or a snap-fit (or pressure fit) connection wherein a raised annular ring inside cap  200  is pressed past a raised annular ring on end  104 . This secures cap  200 , but does not tighten it to, body portion  102 . Cap  202  is secured to second end  110  in the same manner.  
      In this embodiment, first cap  200  and second cap  202  have the same structure so only cap  202  shall be described in detail. Cap  202  has an opening  204  leading to a tapered, inner cavity  206  (shown in  FIG. 3 ), and further includes threads in cavity  206 . Cap  202  also includes a tip  210  having an opening  202 A through which the guide wire can pass and cap  200  includes a tip  212  having an opening  200 A through which the guide wire can pass. First cap  200  and/or second cap  202  may also include one or more cap handling surfaces  208  to assist in tightening and loosening each or either of the caps to body portion  102 . Each handling surface  208  can be any structure suitable for this purpose. Cap  200  is tightened to body portion  102  by screwing it onto threaded portion  108 . Cap  202  is tightened to body portion  102  by screwing it onto threaded portion  114 .  
      While caps  200 ,  202  are shown as screw-on caps, other methods of tightening first cap  200  and second cap  202  to body portion  102  may be used as long as the respective cap, when tightened to body portion  102 , compresses the plurality of fingers on the respective collet  106 ,  112  with which the cap is associated to grip a guide wire. For example, one or both caps may snap onto body portion  102 , or the caps may be non-removable screw-on or snap-on chucks that compress the fingers when tightened. Additionally, as previously stated, a device according to the invention may use any suitable structure for gripping a guide wire; it need not use collets and caps.  
      Device  100  is in the open position when first cap  200  and second cap  202  are loosened sufficiently (i.e., are each in the loosened position), such that a guide wire may be fed through one of the cap openings  200 A or  202 A, through opening  120  and out the other cap opening  200 A or  202 A. Device  100  is in the closed position when caps  200 ,  202  are tightened, causing the fingers of the first collet  106  and the fingers of the second collet  112  to radially compress such that the collets compress against any guide wire present, thereby applying pressure to and gripping the guide wire at two locations (as used herein, “location” means any separate point or area of contact on a guide wire). First cap  200  and second cap  202  may be tightened or loosened in any order, or may be loosened or tightened simultaneously. As shown in  FIG. 3 , cap  200  is in the tightened position and cap  202  is in the loosened position.  
      When a guide wire is positioned in device  100  and device  100  is in the closed position, device  100  can be manipulated by a surgeon or other user to provide torque and/or force to the guide wire. Handling surfaces  102 C and/or  208 , if used, assist in the manipulation of device  100 . By manipulation of device  100  the guide wire can be steered into and passed through blood vessels or other body structures. Device  100  may also be used to manipulate a guide wire when only gripping the guide wire at one location, but it is preferred that device  100  be used by gripping a guide wire at more than one location in which case greater torque may be applied to the guide wire.  
      Therefore, device  100  can grip a single guide wire at more than one location. By gripping the guide wire at more than one location, the guide wire is held more securely and greater torque (and hence greater or easier manipulation of the guide wire through a blood vessel) or force can be transmitted to the wire. Gripping the wire at more than one location also yields the added benefit of reduced potential to damage the wire&#39;s coating due to load sharing between the multiple locations. Also, in the preferred embodiment of the present invention, having a cap on each side of the device, the guide wire can be easily inserted through either side of the device.  
       FIGS. 4 and 4 A show an alternate cap  300  that can also be used to practice the invention. A cap  300  may be used with body portion  102  in place of cap  200  and/or a cap  300  may be used in place of cap  202 . Cap  300  includes a snout  400  that extends from a base portion  302 . Snout  400  includes a structure  404  for securing a body portion (such as a blood vessel) or other object to cap  300  and a tip  406 . In this embodiment, structure  404  comprises an annular bump and a body portion or other object is preferably attached to cap  300  via a suture ligature between structure  404  and base  302 . In all other respects, a device utilizing body portion  102  and one or two caps  300  is the same as previously described device  100 .  
      The purpose of snout  400  (and snouts  400 ′ (shown in  FIGS. 5 and 5 A) and  400 ″ (shown in  FIGS. 6 and 6 A) described below) is to assist the surgeon in introducing a guide wire into a lumen, such as the lumen of a blood vessel or cannula (particularly the cannula of a luer lock). Any snouts according to the invention must only be sufficiently long and narrow for this purpose. In the. preferred embodiment snout  400  (and all snouts described herein) is preferably between ½″-1¼″ in length from the base (here, base  302 ) to the tip (here, tip  466 ) and is most preferably about ¾″ in length (with one embodiment being 0.754″ in length). The outside diameter of tip  406  (and the tips of all snouts herein) is preferably less than 4.5 mm and most preferably about 0.94″. However, the invention is not limited to these specific dimensions.  
       FIGS. 5 and 5 A show a cap  500  that can be used to practice the invention. A cap  500  may be used with body portion  102  in place of cap  200  and/or a cap  500  may be used in place of cap  202 . Cap  500  has a snout  400 ′ (that as shown has the same configuration as snout  400 ) and includes a structure  502  for securing a blood vessel or other object to cap  500 , preferably with a suture ligature, a base  504  and a tip  506 . As shown, structure  502  is an annular ridge, but may be any suitable structure formed on or attached to cap  500  for securing a body member or other object to cap  500 . In all other respects, a device utilizing body portion  102  and one or two caps  500  is the same as previously described device  100 .  
       FIGS. 6 and 6 A show a cap  600  that can be used to practice the invention. Cap  600  has a snout  400 ″ (that as shown has the same structure as snout  400 ) a structure  602  for securing a blood vessel or other object to cap  600 , a base  604  and a tip  606 . As shown, structure  602  is a bulb formed in snout  400 ″. A cap  600  may be used in place of cap  200  and/or a cap  600  may be used in place of cap  202 . In all other respects, a device utilizing body portion  102  and one or two caps  600  is the same as previously described device  100 .  
      Structure  404 ,  502  or  602  is designed to assist in securing a suture ligature to cap  300 ,  500  or  600 , respectively, in order to secure a body member (such as a blood vessel) or other object to a device according to the invention, particularly to assist in the removal of a blood vessel in a vein or artery harvesting procedure. However, any object may be secured to a device according to the invention for any reason and, as used herein, the expression “secure a body member” includes both body members and other objects. Any suitable structure may be formed on or mounted to a device according to the invention for that purpose. In the vein harvesting procedure, securing a blood vessel to a device according to the invention may be done prior to straightening the blood vessel. Generally, to straighten a blood vessel, the blood vessel is first accessed at two positions, then a guide wire is fed through the blood vessel and is exposed at both positions, which are called proximal and distal positions. When harvesting a blood vessel, a torque device according to the invention is placed on the guide wire at the proximal position outside of the blood vessel and another device according to the invention is placed on the distal position outside of the blood vessel. An intravascular catheter is passed over the guide wire and through the accessed portion of the blood vessel thus supporting the blood vessel. The blood vessel is then secured to a structure  404 ,  502 , or  602  by a suture ligature and the guide wire, catheter and vessel are pulled straight by applying force to a device to which one or more caps  300 ,  500  or  600  are attached.  
       FIGS. 7 and 7 A show another alternative cap  700  that can be used with a device according to the invention, wherein the cap can receive the end of a guide wire package. A cap  700  may be used in place of cap  200  and/or a cap  700  may be used in place of cap  202  on body portion  102 . As known to those skilled in the art, guide wires are typically packaged in tubular plastic sheaths. Cap  700  has a wide, blunt snout  800  and includes a tip  802  having an opening  804  that leads to cavity  806 . Opening  804  and cavity  806  are dimensioned to receive the end of a guide wire package (not shown). Opening  804  and cavity  806  can be of any configuration suitable for receiving the end of a guide wire package so that a torque device utilizing cap  700  remains mounted on the guide wire package during shipping without causing significant damage to the guide wire. This helps to prevent the guide wire or the device from being damaged during shipping or handling. Opening  804  and cavity  806  dimensioned according to the guide wire package they are to receive, but in two embodiments cavity  806  is cylindrical and has diameters of 0.118″ and 0.154″, respectively. In these embodiments, the depth D of cavity  806  is at least as deep as the diameter of cavity  806 , preferably greater than twice as deep as the diameter of cavity  806  and most preferably about 2½ times the diameter of cavity  806 . Furthermore, cap  700  may include a structure for securing a blood vessel or other object thereto. In all other respects, a device utilizing body portion  102  and one or two caps  700  is the same as previously described device  100 .  
      It will be understood that, although a torque device according to the invention could include two caps  300 , or two caps  500 , or two caps  600 , it is preferred that a device according to the invention, if it includes one of these caps, only include one. Since these caps each include a snout for directing a guide wire into a lumen, there likely would only be a need for only one at one end of a torque device. Further, while a torque device according to the invention could include two caps  700 , it is preferred that, if a torque device includes a cap  700 , only one cap  700  be used because only one end of the torque device would be secured to a guide wire package for shipping.  
      Any of caps  300 ,  500 ,  600  or  700  may include one or more of the previously described handling surfaces  208 . Furthermore, if a device according to the invention utilizes a cap  300 ,  500 ,  600  or  700 , it need only include one guide wire gripping structure, such as a single one of the previously described collets or any other suitable structure for gripping a guide wire. In that case, a body portion with which one or more of caps  300 ,  500 ,  600  or  700  is used may still have two caps, but at least one of the caps would not assist in compressing the guide wire. Additionally, a torque device according to the invention, if it includes two caps, may have any combination of caps  200 ,  300 ,  500 ,  600  and  700 . For example, a device may have body portion  102 , a cap  300  and a cap  700 , and one or both of the caps could function with a collet or other structure to grip a guide wire. Moreover, a snout, a structure for securing a body part or other object to a device according to the invention, or an opening or other structure for receiving or connecting to the end of a guide wire package could be formed in the body portion of the device rather than in a cap. In that case, the body portion would still have one or more structures for gripping a guide wire and could still optionally have at least one of the previously described caps. For example, a torque device may have a body portion that includes only a single wire gripping structure, such as a collet, a cap  300  that functions with the collet to grip a guide wire, and an opening formed in the body portion opposite cap  300  wherein the opening is dimensioned to receive an end of a guide wire package.  
      Turning now to  FIGS. 8-10 , an alternate device  900  is shown. Device  900  includes two caps  920  and  922  and a body portion  940 . Body portion  940  may include one or more gripping structures. If included, the gripping structures would assist in the gripping and manipulation of device  900  in the same manner as described with respect to device  100 .  
      Body portion  940  includes a first end  924  that has a collet  926  and a threaded portion  928 , and first end  940  as shown has the same structure and function as previously described first end  104 . Body portion  940  also includes a second end  930  that has a collet  932  and a threaded portion  934 . As shown second end  930  has the same structure and function as previously described second end  11 O.  
      As shown in  FIG. 8 , an opening  950  is defined through body portion  940 , and is designed to be sufficiently large enough to allow the guide wire used with device  900  to be inserted through it when device  900  is in the open position.  
      Body  940  is preferably formed in two pieces,  940 A and  940 B that are pressure fit together, although any method of attachment may be used and body  940  may be formed of any number of pieces. A cavity C is defined within body  940 . A thumb wheel  954  is positioned partially inside cavity C and extends through an opening (shown here as a slot) in the outer surface of body  940 . Drive wheel  954 A is integrally formed with or is attached to thumb wheel  954 . Thumb wheel  954  is mounted on an axle  956  such that it can be rotated. An idler  958  is mounted to or integrally formed as part of section  940 A so that a gap is formed between drive wheel  954 A and idler  958 . The gap is of sufficient distance to allow the guide wire G to pass through it while still providing for a pressure fit between idler  958  and drive wheel  954 A to enable guide wire G to be advanced or retracted by moving thumb wheel  954 , which in turn moves drive wheel  954 A. The purpose of thumb wheel  954 , drive wheel  954 A and idler  958  is to enable a user to move a guide wire positioned inside device  900  without the user having to grip or handle the guide and any structure in or on device  900  suitable for this purpose may be used.  
      Device  900  also includes a first cap  920  and a second cap  922  that are each preferably secured to body portion  940  to allow for easier handling than having multiple, loose pieces. In this embodiment, first cap  920  and second cap  922  each have the same structure and function as previously described cap  202 . Alternatively, body portion  940  may be used with one or two of caps  300 ,  500 ,  600  and/or  700 .  
      A device according to the invention that includes a mechanism for advancing or retracting a guide wire may only include one structure for gripping guide wire G when the device is in the closed position. Alternatively, it may not include any dedicated gripping structures because the pressure between drive wheel  954 A and idler  958  may be sufficient to apply torque to the guide wire and direct it. In that case, the mechanism may have an open position in which the guide wire may be threaded through an opening in the mechanism larger than the guide wire, and a closed position wherein pressure is applied by the mechanism to grip the wire. Alternatively, the mechanism may have a single position and the guide wire may be threaded through the mechanism by advancing it using the mechanism. For example, referring to the mechanism shown as the preferred embodiment, the guide wire may be threaded up to the gap between drive wheel  954 A and idler  958  and then thumb wheel  954  may be turned to advance the guide wire through the gap.  
       FIG. 11  shows an alternate device  1000  according to the invention. As shown, device includes a cap  500  and a cap  700 . Device also includes a body portion  150  that has an opening  152  in which a guide wire G is positioned, a center portion  154  and an opening  156  in center portion  154 . The ends of body portion  150 , which engage the caps and (in the preferred embodiment) include collets for gripping a guide wire in the manner previously described, preferably have the same structure as those on previously described body portion  102 . A bridge  158  is preferably formed in the bottom of opening  156  and is preferably a rounded, smooth ridge that extends substantially the width of opening  156 . Opening  156  exposes guide wire G positioned in cavity  152  and a user can advance or retract guide wire G by applying pressure to the exposed guide wire and pressing it against bridge  158 . Any structure suitable to create a pressure fit between a user&#39;s thumb or finger in order to advance or retract a guide wire may be used in place of bridge  158 , and the pressure fit may simply be made between the user&#39;s finger and the lower surface of opening  156 .  
      Having thus described different embodiments of the invention, other variations and embodiments that do not depart from the spirit of the invention will become readily apparent to those skilled in the art. The scope of the present invention is thus not limited to any one particular embodiment, but is instead set forth in the appended claims and the legal equivalents thereof.