Abstract:
Disclosed herein is an applicator that can be advanced over an in-situ guidewire and into the subcutaneous tissue or tract prior to CVC placement or replacement, allowing sterilization of the subcutaneous tissue or tract before CVC introduction. The unique shape of the applicator allows sterilization of the skin surface as well as the subcutaneous tissue or tract of the original CVC that lies beneath the skin, which are difficult to reach and effectively sterilize with other applicators.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Central line associated blood stream infection (CLABSI) is a potentially devastating consequence of indwelling central venous catheters. It is estimated that a single CLABSI costs $35,000 to treat and associated complications (sepsis, endocarditis) can be life threatening. Since 2011, hospitals participating in the Center for Disease Control&#39;s National Healthcare Safety Network have been required to report their incidence of CLABSI. While the rates of CLABSI have declined in recent years with heightened awareness, chlorhexidine skin antiseptic, and antibiotic impregnated catheter use, it remains a vexing problem. 
         [0002]    It had been known for decades that normal skin bacteria inhabit both the skin surface (also known as the stratum corneum) as well as structures that lie in deeper layers of the skin—including hair follicles, sweat glands and ducts and sebaceous glands and ducts. These bacteria are not eradicated by standard antimicrobial skin cleansing and preparation, as these antimicrobials do not reliably penetrate beyond the most superficial skin layer. Recent evidence in the medical literature suggests that these deep bacterial reservoirs often contaminate central venous catheters (CVCs) and may predispose to CLABSI development. Thus a need exists for a device that can effectively and reliably eradicate bacterial reservoirs in the deep layers of the skin prior to CVC placement. 
         [0003]    In addition, patients with CVCs often require the CVCs to be changed during their hospital stay. This can be accomplished in one of two ways: 
         [0004]    1) Placement of a new CVC at a new location (commonly called the ‘fresh stick’ technique); or 
         [0005]    2) Removing the existing CVC over a guidewire and then using the guidewire to direct a new CVC through the skin and into the original CVC site Cover wire&#39; technique). 
         [0006]    Each technique has its advantages and disadvantages. The fresh stick technique carries a significantly lower rate of infection, but a higher rate of mechanical complications as a new central vein must be accessed for placement. On the other hand, the change over wire technique is technically much simpler and carries a lower mechanical complication rate but is associated with a much higher rate of CVC bacterial colonization and CLABSI. 
         [0007]    Despite the fact that practitioners employ sterile technique during both de novo CVC placement as well as over the wire exchange, CLABSI occurs at a much higher rate with the over the wire technique than during de novo CVC placement. It is believed that bacteria colonize the path that the indwelling CVC follows from the skin to the central vein. This subcutaneous tract bacterial colonization (TBC) likely leads to contamination of the new CVC during over the line CVC exchange, accounting for the higher infection rates observed with this technique. Thus, a need clearly exists for a device capable of reducing infections during CVC over the wire exchanges. 
       SUMMARY OF THE INVENTION 
       [0008]    In order to combat subcutaneous CVC, disclosed herein is an applicator that can be advanced over an in-situ guidewire and into the subcutaneous tissue or tract prior to CVC placement or replacement, allowing sterilization of the subcutaneous tissue or tract before CVC introduction. The unique shape of the applicator allows sterilization of the skin surface as well as the subcutaneous tissue or tract of the original CVC that lies beneath the skin, which are difficult to reach and effectively sterilize with other applicators. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a top view of the applicator. 
           [0010]      FIG. 2  is a perspective view of the applicator. 
           [0011]      FIG. 3  is a side view of the applicator. 
           [0012]      FIG. 4  is a front view of the applicator. 
           [0013]      FIG. 4A  is a cut-away view of the applicator. 
           [0014]      FIG. 5  shows a perspective view of the combined dilator/applicator. 
           [0015]      FIG. 6  shows a side view of the combined dilator/applicator. 
           [0016]      FIG. 7  shows a front view of the combined dilator/applicator. 
           [0017]      FIG. 7A  shows a cut-away view of the combined dilator/applicator. 
           [0018]      FIG. 8  shows a top view of a combined dilator/applicator with a medicament delivery device. 
           [0019]      FIG. 9  shows a side view of the dilator/applicator with the medicament delivery device. 
           [0020]      FIG. 10  shows a side view of the dilator/applicator with the medicament delivery device. 
           [0021]      FIG. 11  shows an alternate side view of the dilator/applicator with the medicament delivery device. 
           [0022]      FIG. 12  shows a perspective view of the dilator/applicator with the medicament delivery device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    With reference to  FIGS. 1-4A , shown is applicator  100 , and  FIGS. 5-7A  shown is combined applicator/dilator  100 A which comprises shaft  102  and thumbwheel  104 . Shaft  102  is formed as a cylindrical hollow tube which is sized to advance over a guidewire  106  and fit snugly in the subcutaneous tract. Similarly, thumbwheel  104  is formed as a larger cylinder having a central channel similar in size to that of shaft  102 . The greater diameter of thumbwheel  104  prevents the entirety of applicator  100  from inadvertently entering the subcutaneous tract. 
         [0024]    In some embodiments, shaft  102  may extend the entire length of applicator  100 , through thumbwheel  104 , and form the inner channel of thumbwheel  104 . The inside of thumbwheel  104  may be hollow or solid depending upon the manufacturing method used (e.g., thermoplastic molding) or the desired use of applicator  100 . 
         [0025]    Another possible implementation of applying medication or disinfectant to the outside and/or inside of shaft  102  is to include a reservoir in applicator  100  with a mechanism allowing the release of the medication or disinfectant. This reservoir will likely, but not necessarily, be located within the thumbwheel  104 . 
         [0026]    An outer surface of shaft  102  is covered with a fabric like cover or other medium which is capable of holding or absorbing antiseptic or other medication. A grommet  110  located at an end of shaft  102  may be used to prevent the fabric like cover or other medium from sliding off of applicator  100  during application of the antiseptic or other medication. Preferably, shaft  102  and grommet  110  are tapered for easy passage of applicator  100  into the subcutaneous tract of the patient. The fabric like cover or other medium may be applied to the surface of shaft  102  using any known methods such as adhesives, chemical bonding, etc. 
         [0027]    In some embodiments, an inner surface of shaft  102  may also comprise a fabric like cover or other medium similar to that on the outer surface of shaft  102 . This allows antiseptic or other medication to be applied to the inner surface of shaft  102  to treat/disinfect guidewire  106  as applicator  100  is advanced over guidewire  106 . 
         [0028]    A bottom surface  108  of thumbwheel  104  may also be covered with a fabric like cover or other medium for holding antiseptic or other medication. When applicator  100  is advanced to the skin surface, the bottom surface  108  is used to apply the antiseptic or medication to the skin surface as applicator  100  is rotated. 
         [0029]    In one embodiment, a diameter of thumbwheel  104  is approximately 19 mm wide. The length of shaft  102  may be 16 mm with a diameter of 2.5 mm. These dimensions allow applicator  100  to be used on many different sized guidewires  106 . However, it should be apparent that any dimensions for applicator  100  may be used depending on the desired application. 
         [0030]    Preferably, applicator  100  is packaged in a single-use sterilized package similar to other medical equipment such as needles or syringes. Applicator  100  may come pre-soaked (i.e., with antiseptic/medication already applied) or the antiseptic/medication may be applied separately. For example, in certain situations, specialized medications or different combinations of medications may be desired. 
         [0031]    In a preferred embodiment, the sidewalls of thumbwheel  104  have a textured surface  112  to allow for easy rotation of applicator  100  by use of a practitioner&#39;s thumb after applicator  100  has been advanced into the subcutaneous tract. The textured surface  112  also allows a practitioner to easily grip and advanced applicator  100  over the guidewire. 
         [0032]    In order to use applicator  100  during CVC placement, the operating field (skin) is prepped with antimicrobial solution and sterilely draped. The practitioner accesses the target blood vessel with a needle through which a guidewire  106  is placed into the vessel of interest. The needle is removed, leaving guidewire  106  in-situ. A tissue dilator is then passed over the guidewire  106  to widen the subcutaneous tract. In certain embodiments, applicator  100 A may serve as both an applicator and a tissue dilator simultaneously where tapered end  113  widens the opening as would a tissue dilator: and the tissue dilator step can be skipped. Applicator  100  is then passed over guidewire  106  (with shaft  102 ) first and into the subcutaneous tissue. As applicator  100  is advanced, any antiseptic/medication located on the inside of shaft  102  is passed to the surface of guidewire  106  for sterilization. The practitioner rotates applicator  100  using thumbwheel  104  to apply the antiseptic/medication to the surface of the skin of the patient from bottom surface  108  and the subcutaneous tract from the outer surface of shaft  102 . Applicator  100  is then removed from guidewire  106  and the CVC is placed using guidewire  106 . Guidewire  106  is removed leaving the new CVC in place. With the use of applicator  100 , both the subcutaneous tissue and the guidewire are sterilized prior to CVC introduction, thereby reducing the risk of CVC contamination. 
         [0033]    In order to use applicator  100  during over the wire exchange, the CVC field is prepped with a skin antiseptic and sterilely draped. The practitioner passes guidewire  106  through the CVC and removes it, leaving guidewire  106  in-situ. Applicator  100  is then passed over guidewire  106  (with shaft  102  first) and into the subcutaneous tract. As applicator  100  is advanced, any antiseptic/medication located on the inside of shaft  102  is passed to the surface of guidewire  106  for sterilization. The practitioner rotates applicator  100  using thumbwheel  104  to apply the antiseptic/medication to the surface of the skin of the patient from bottom surface  108  and the subcutaneous tract from the outer surface of shaft  102 . Applicator  100  is then removed from guidewire  106  and a new CVC is placed using guidewire  106 . Guidewire  106  is removed, leaving the new CVC in place. With the use of applicator  100 , patients can benefit from the low risk of mechanical complications associated with the over the wire technique, without an appreciable increase in risk of CLABSI. 
         [0034]    An alternate embodiment of applicator  100  is depicted in  FIGS. 8-12 . As shown, applicator  100  is fashioned of hard plastic with a central lumen  200  to allow applicator  100  to pass over guidewire  106 . Alternative to perforations, central lumen  200  can also be manufactured from a porous material. The multiple perforations in central lumen  200  allow spread of injected antiseptic or medicament to reach subcutaneous tissues as well as guidewire  106 . 
         [0035]    In order to receive the medicament, applicator  100  comprises valve body  201  which has a port  203  allowing connection for a syringe  202  or other medicament delivery system. Port  203  may have a threaded connection for connecting to syringe  202 . Also, port  203  may be provided with a cover when syringe  202  is not attached. Syringe  202  is used to inject medicament which is then dispersed through central lumen  200 , coating its inner and outer surface. This allows for administration of medicament to both guidewire  600  and the subcutaneous tissues.