Abstract:
The invention relates to a guidewire advancer having a roller wheel to facilitate the advancement of the guidewire from the guidewire advancer and into a patient&#39;s blood vessel. If desired the roller wheel can have a roughened or slotted circumferential surface.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The subject invention relates to a device that allows the controlled insertion of a guidewire into a blood vessel. Such a device is referred to generally as a guidewire advancer. More particularly, the subject invention relates to a guidewire advancer having a roller wheel to facilitate the advancement of the guidewire from the guidewire advancer and into a patient&#39;s blood vessel.  
           [0002]    Guidewires are well known in the art. They are typically made from a tightly wound surgical grade stainless steel wire of small diameter so as to be highly flexible yet stiff and resilient. These characteristics allow guidewires to be inserted into a patient&#39;s vasculature or body cavity and accurately positioned therein. Although guidewires may be employed in a number of different ways, they are generally used to introduce a catheter into a blood vessel.  
           [0003]    For example, catheters such as midline catheters, central catheters and peripherally inserted central catheters may be used for certain types of IV therapy. Specifically these catheters are used when certain harsh medicaments must be infused into the patient and must be diluted quickly in a large vein to prevent adverse reaction by the patient. In such a situation, it is important for the distal tip of the catheter to be located in the auxiliary, subclavian or brachiocephalic vein or in the superior vena cava. Midline catheters, central catheters and peripherally inserted central catheters, which can be on the order of several inches long or longer, fill this need.  
           [0004]    For these longer catheters, guidewires can be used to facilitate the introduction and proper placement of the catheter into a patient. One method of inserting guidewires and catheters into a patient is by the modified Seldinger technique. With this technique, the clinician first inserts a hypodermic needle via a syringe into the patient&#39;s blood vessel. Vascular access is confirmed by pulling a small amount of blood through the hypodermic needle into the syringe. Thereafter, the syringe is removed leaving the hypodermic needle in place. The clinician then inserts a guidewire through the hypodermic needle into the patient and advances the guidewire until the distal end of the guidewire reaches the target site. Thereafter, the catheter is inserted into the patient over the guidewire, which acts as a track to facilitate the proper placement of the catheter in the patient. Alternatively, an introducer can be inserted into the patient&#39;s vasculature instead of the hypodermic needle and the guidewire can be advanced into the patient through the introducer.  
           [0005]    Because of the tortuous path of a patient&#39;s vasculature, a long guidewire is needed to ensure that the distal end of the guidewire is adjacent to the target site and a suitable length of the guidewire extends outside of the patient&#39;s body. A length of guidewire must extend outside of the patient&#39;s body to allow the clinician to be able to handle the guidewire and thread the catheter onto the proximal end of the guidewire without losing control of the guidewire placement within the patient&#39;s body. Thus, guidewires can be many feet in length. However, such a length makes the initial insertion of the guidewire into a patient awkward and difficult. Previously, an assistant would control the proximal portion of the guidewire as the clinician inserted the guidewire into the patient. In these cost conscious times, the employment of an assistant during guidewire placement is unacceptable.  
           [0006]    Devices currently on the market have been developed to avoid the need for an assistant during guidewire placement. Such devices known as guidewire advancers include a hollow coiled plastic tube that houses the guidewire and makes it easier for the clinician to handle the guidewire. In addition, the tube may include an aperture adjacent to one end of the tube to allow the clinician to access the guidewire. In this way, the clinician could place a finger through the aperture, contact the guidewire and, with the friction between the clinician&#39;s finger and the guidewire, advance the guidewire from the tube and into the patient.  
           [0007]    Although these devices work generally for their intended purpose they could be improved. For example, during such medical procedures, the clinician&#39;s hands will become covered with blood and other body fluids making the clinician&#39;s hands slippery. In addition, the guidewire and the guidewire advancer will become covered with blood and other body fluids. This will make it difficult for the clinician to properly grip the guidewire to advance it from the guidewire advancer into the patient&#39;s blood vessel. In addition, because the guidewire will feel slippery, it will be difficult for the clinician to accurately gauge how much of the guidewire has actually been advanced from the guidewire advancer into the patient. In addition, these previous devices may have a flat surface under the aperture against which the clinician manipulates the guidewire. Such a flat surface exacerbates the problem of poor frictional contact between the clinician&#39;s finger and the guidewire and gives the clinician a poorer feel of the guidewire as discussed above. Previous designs also could be improved ergonomically.  
         SUMMARY OF THE INVENTION  
         [0008]    It is therefore an object of this invention to provide a guidewire advancer that allows the clinician to securely grip the guidewire so that the guidewire can be easily advanced from the guidewire advancer and into a patient.  
           [0009]    It is another object of this invention to provide a guidewire advancer that allows the clinician to accurately gauge how much of the guidewire has been advanced from the guidewire advancer into the patient.  
           [0010]    It is still another object of this invention to provide a guidewire advancer that has an improved ergonomic design to provide the clinician with a proper feel of the guidewire.  
           [0011]    The guidewire advancer of this invention comprises an elongate tube having a first outlet at a first end and a second outlet at a second end, a body member having a proximal portion, a central portion and a distal portion, wherein the proximal portion of the body member is connected to the first outlet of the elongate tube, and a roller wheel rotatably connected to the body member adjacent to the central portion thereof. Both the proximal portion and the distal portion of the body member define a passage therein for allowing a guidewire to extend therethrough. Preferably, the passage of the proximal portion of the body member is radially offset from the passage of the distal portion of the body member such that the passage of the proximal portion of the body member is above the passage of the distal portion of the body member.  
           [0012]    The roller wheel defines a circumferential surface that is rough and is preferably serrated where the peaks are radiused and extend across the width of the circumferential surface. Alternatively, the circumferential surface could be formed with some other configuration that results in a rough surface having a high coefficient of friction as compared to a smooth surface. For example, the circumferential surface could be formed with a plurality of protrusions or recesses, such as pits or cross hatched score lines formed therein. In addition, the roller wheel could be formed such that the circumferential surface is formed as a channel or slot with sidewalls. The axis about which the roller wheel rotates is preferably radially offset from the passage of the proximal portion of the body member such that the axis is below the passage of the proximal portion of the body member. Even more preferably, the circumferential surface of the roller wheel is below the passage of the proximal portion of the body member.  
           [0013]    If desired, an end cap may be placed over the second outlet of the elongate tube to prevent the guidewire from slipping out the back of the guidewire advancer. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The preferred embodiments are illustrated in the drawings in which like reference numerals refer to like elements and in which:  
         [0015]    [0015]FIG. 1 is an exploded perspective view of the roller wheel assisted guidewire advancer of this invention;  
         [0016]    [0016]FIG. 2 is a perspective view of the roller wheel assisted guidewire advancer of this invention;  
         [0017]    [0017]FIG. 3 is a side elevation view of the roller wheel assisted guidewire advancer of this invention showing a clinician&#39;s hand in phantom to demonstrate how the roller assisted guidewire advancer of this invention is used;  
         [0018]    [0018]FIG. 4 is an enlarged cross sectional view of the body member of the roller wheel assisted guidewire advancer of this invention incorporating the roller wheel;  
         [0019]    [0019]FIG. 5 is an enlarged perspective view of one embodiment of the roller wheel used in the roller wheel assisted guidewire advancer of this invention;  
         [0020]    [0020]FIG. 6 is an enlarged perspective view of a second embodiment of the roller wheel used in the roller wheel assisted guidewire advancer of this invention;  
         [0021]    [0021]FIG. 7 is an enlarged perspective view of a third embodiment of the roller wheel used in the roller wheel assisted guidewire advancer of this invention;  
         [0022]    [0022]FIG. 8 is an enlarged perspective view of a fourth embodiment of the roller wheel used in the roller wheel assisted guidewire advancer of this invention; and  
         [0023]    [0023]FIG. 9 is an enlarged perspective view of a fifth embodiment of the roller wheel used in the roller wheel assisted guidewire advancer of this invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    As used herein, the term “proximal” refers to a location on the device that is closest to the clinician using the device and farthest from the patient in connection with whom the device is used when the device is used in its normal operation. Conversely, the term “distal” refers to a location on the device that is farthest from the clinician using the device and closest to the patient in connection with whom the device is used when the device is used in its normal operation.  
         [0025]    As used herein, the term “top”, “up”, “above” or “upwardly” refers to a location with respect to the device that, during normal use, is radially away from the longitudinal axis of the device and away from the patient&#39;s skin. Conversely, as used herein, the term “bottom”, down”, “below” or “downwardly” refers to a location with respect to the device that, during normal use, is radially away from the longitudinal axis of the device and toward the patient&#39;s skin.  
         [0026]    As used herein, the term “in” or “inwardly” refers to a location with respect to the device that, during normal use, is toward the inside of the device. Conversely, as used herein, the term “out” or “outwardly” refers to a location with respect to the device that, during normal use, is toward the outside of the device.  
         [0027]    The guidewire advancer  10  of this invention comprises an elongate tube  20  having a first outlet  21  at its distal end and a second outlet  22  at its proximal end, a body member  30  having a proximal portion  31 , a central portion  32  and a distal portion  33 . First outlet  21  of elongate tube  20  is connected to proximal portion  31 . Tube  20  is preferably coiled to facilitate handling of guidewire advancer  10  by a clinician. If desired, a slot  35  may be formed in body member  30  to allow tube  20  to fit therein and hold tube  20  in a coiled position. In addition, a clip  36  may be used to clip adjacent sections of tube  20  together to hold tube  20  in a coiled position. A roller wheel  40  is rotatably connected to body member  30  adjacent to central portion  32  so that the axis of rotation of roller wheel is transverse to the longitudinal axis of body member  30 . Proximal portion  31  of body member  30  defines a proximal passage  31  a therein to allow a guidewire  100  to extend therethrough. Similarly, distal portion  33  of body member  30  defines a distal passage  33   a  therein to allow guidewire  100  to extend therethrough. When guidewire  100  is located in guidewire advancer  10 , guidewire  100  extends through tube  20 , proximal passage  31   a , over roller wheel  40  and through distal passage  33   a . This configuration allows the clinician to easily access guidewire  100  adjacent to body member  30  in the space between proximal passage  31   a  and distal passage  33   a . Preferably, the clinician&#39;s finger contacts guidewire  100  when guidewire  100  is on roller wheel  40 . In this way, the clinician can securely grip guidewire  100  against roller wheel  40  and thus can easily advance guidewire  100  as roller wheel  40  is rotated in the direction of the desired movement of guidewire  100 . In addition, the clinician can accurately gauge how much of guidewire  100  has been advanced from guidewire advancer  10  into the patient because the clinician will be able to feel or see roller wheel  40  rotate as guidewire  100  is advanced from guidewire advancer  10 .  
         [0028]    Preferably, proximal passage  31   a  is radially offset from distal passage  33   a  such that proximal passage  31   a  is above distal passage  33   a . This radially offset arrangement creates a tortuous path for guidewire  100  as it extends between proximal passage  31   a  and distal passage  33   a . Proximal passage  31   a  and distal passage  33   a  thus gently hold guidewire  100  in place and significantly reduce the tendency for guidewire  100  to drift out of guidewire advancer  10  when it is being shipped, handled or otherwise manipulated. This radially offset arrangement also presents an ergonomically beneficial arrangement for the clinician. Although it is possible for proximal passage  31   a  to be below or axially aligned with distal passage  33   a , such an arrangement is not preferred because it will not supply all of the advantages achieved when proximal passage  31   a  is above distal passage  33   a.    
         [0029]    Roller wheel  40  defines a circumferential surface  41  that is rough and preferably is serrated where the peaks  42  are radiused and the serrations extend across the width of circumferential surface  41 , i.e. parallel to the axis of rotation of roller wheel  40 . See FIGS. 4 and 5. Alternatively, the circumferential surface could be formed with some other configuration that results in a rough surface having a high coefficient of friction as compared to a smooth surface. For example, the circumferential surface could be formed with a plurality of protrusions or recesses, such as pits or cross hatched score lines formed therein. See circumferenatial surfaces  41   b - 41   c  in FIGS.  7 - 9 . In addition, the circumferential surface could include a rubberized surface or otherwise be covered with a material having a high coefficient of friction as compared to a smooth surface.  
         [0030]    Roller wheel  40  should be wide enough to minimize the chances that guidewire  100  will slide off of the side of circumferential surface  41  during use. For example, roller wheel  40  should be at least about 3 millimeters wide when used with a standard guidewire. Alternatively, roller wheel  40  could be formed such that the circumferential surface is formed as a channel or slot with sidewalls to affirmatively hold guidewire  100  therein. See circumferential surface  41  a in FIG. 6. Such a configuration ensures that guidewire  100  will not become disengaged from the surface of roller wheel  40 .  
         [0031]    The axis about which roller wheel  40  rotates is preferably radially offset from proximal passage  31   a  such that the axis is below distal passage  33   a . Preferably this results in the top of roller wheel  40  being slightly above distal passage  33   a  such that it is aligned with or slightly above a line connecting the distal end of proximal passage  31   a  with the proximal end of distal passage  33   a . With this arrangement, and where proximal passage  31   a  is above distal passage  33   a , circumferential surface  41  will extend into the path of guidewire  100  as it extends between proximal passage  31   a  and distal passage  33   a . This will ensure that circumferential surface  41  will frictionally engage guidewire  100  to prevent unwanted movement of guidewire  100  with respect to guidewire advancer  10  and will allow the clinician to easily grip and advance guidewire  100 .  
         [0032]    If desired, an end cap  37  may be placed over the second outlet of elongate tube  20  to prevent guidewire  100  from slipping out the back of guidewire advancer  10 .  
         [0033]    Thus, it is seen that a guidewire advancer is provided that allows the clinician to securely grip the guidewire so that the guidewire can be easily advanced from the guidewire advancer and into a patient, to accurately gauge how much of the guidewire has been advanced from the guidewire advancer into the patient and that has an improved ergonomic design to provide the clinician with a proper feel of the guidewire.