Abstract:
A percutaneous port comprises a port body defining a cavity and a first catheter channel adapted to allow passage of a catheter thereinto a shuttle removably received within the cavity, the shuttle including a first flow conduit which, when the shuttle is received within the cavity, extends to the first catheter channel and a sealing mechanism sealing the first flow conduit when a fluid pressure applied thereto is less than a threshold value and opening to permit flow therethrough when the fluid pressure applied thereto is at least the threshold value a cover releasably attachable to the port body to enclose the cavity.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Treatments for chronic diseases often require repeated and prolonged access to the vascular system to, for example, provide therapeutic agents thereto and/or remove fluids therefrom. However, complications are associated with most of the various methods for providing this access.  
       SUMMARY OF THE INVENTION  
       [0002]     The present invention is directed to a percutaneous port comprising a port body defining a cavity and a first catheter channel adapted to allow passage of a catheter thereinto and a shuttle removably received within the cavity, the shuttle including a first flow conduit which, when the shuttle is received within the cavity, extends to the first catheter channel in combination with a sealing mechanism sealing the first flow conduit when a fluid pressure applied thereto is less than a threshold value and opening to permit flow therethrough when the fluid pressure applied thereto is at least the threshold value and a cover releasably attachable to the port body to enclose the cavity. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0003]      FIG. 1  is a cross sectional view showing an embodiment of a percutaneous access port according to the invention;  
         [0004]      FIG. 2  is a perspective view of a shuttle of the percutaneous access port shown in  FIG. 1 ;  
         [0005]      FIG. 3  is a perspective view showing a cross section of the port body of the percutaneous access port shown in  FIG. 1 ;  
         [0006]      FIG. 4  is a perspective view of the shuttle in place within the port body shown in  FIGS. 2 and 3 ;  
         [0007]      FIG. 5  is a perspective view of a second embodiment of the percutaneous access port according to the invention;  
         [0008]      FIG. 6  is a perspective view of a third embodiment of the percutaneous access port according to the invention;  
         [0009]      FIG. 7  is a perspective view of an embodiment of a locking lid for a percutaneous access port according to the invention;  
         [0010]      FIG. 8  is a perspective view of another embodiment of a locking lid for a percutaneous access port according to the invention;  
         [0011]      FIG. 9  is a perspective view of a different embodiment of a locking lid for a percutaneous access port according to the invention;  
         [0012]      FIG. 10  is a top elevation view showing a different embodiment of a suture flange according to the invention; and  
         [0013]      FIG. 11  is a top elevation view showing an embodiment of a dual lumen port according to the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0014]     The present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The invention relates to devices for accessing the body and, more specifically, devices for accessing the vascular system to add fluids thereto and/or remove fluids therefrom. On exemplary use of a device according to the invention is for treatments such as antibiotic therapies, hemodialysis access, chemotherapy regimens, etc. These treatments may last for a month or longer, and in some cases access to the body may be required for years.  
         [0015]     Such long term access is often provided via a subcutaneous access port which is pierced by a needle which enters a reservoir of the port to introduce or withdraw fluids therefrom. The multiple punctures of the skin may cause patient discomfort and, in the long run, damage the skin causing the site of the port to become unusable. The large diameter needles used in procedures such as dialysis and chemotherapy may exacerbate these problems. In addition, the access port&#39;s reservoir may collect debris from the substances injected, coagulating blood or other sources, which may lead to an infection. Replacement or repair of the components of such a port and of the catheter(s) extending therefrom, requires a surgical procedure.  
         [0016]     The various embodiments of the invention enhance the comfort, safety and convenience of the known systems for long term access of the vascular system. In one embodiment according to the invention, a percutaneous access port is provided, comprising a one way valve selectively sealing the port and an improved cover that securely locks in place to close an opening of the port. An additional feature of the exemplary port according to the invention is the ability to replace catheters extending therefrom without surgical intervention and without disturbing the port.  
         [0017]      FIG. 1  shows an exemplary percutaneous port  100  according to the present invention which provides access to internal portions of the body, while minimizing the risk of infection, reducing patient discomfort and facilitating the replacement of catheters extending from the port  100 . The exemplary port  100  comprises a port body  102  which is implanted with a majority of the port body  102  below a surface of the skin  146  and a bottom surface  140  of the port body  102  resting against tissue at the bottom of a surgically formed cavity.  
         [0018]     Formed within the port body  102  are various passages and cavities including a catheter channel  112  for fluidly connecting to the port  102  a catheter (not shown), a distal end of which may be inserted to a target location within the body, for example within a blood vessel or other structure as desired. The catheter channel  112  is sized so that a proximal end of a catheter for use with the port  100  may pass therethrough toward a cavity  114  defined by the port body  102 . Thus, depending on the shape and construction of the catheter, the entire catheter may be drawn through the catheter channel  112  and withdrawn from the body for repair or replacement.  
         [0019]     The port body  102  comprises a flange  144  with perforations which may be employed as anchors for sutures or other fasteners to retain the port  100  in a desired position within the cavity. A removable shuttle  104  including a sealing mechanism (e.g., a PASV valve  110 ) and a guidewire valve bypass  108  is held in a desired position within the cavity  114  of the port body  102  by retaining elements  150 ,  152  which extend into the cavity  114 . The retaining elements  150 ,  152  act on the shuttle  104  by, for example, friction, snap fit or any other suitable method of retaining the shuttle  104  in position. The user may manually release the retaining elements  150 ,  152  when necessary to remove the shuttle  104  from the port body  102 , as will be described in more detail below. The retaining elements  150  and  152  are preferably dimensioned to minimize the size of the port body  102 , while remaining large enough to be easily actuated by a user.  
         [0020]     In a different embodiment, the flange  144  may be made smaller to reduce the overall dimensions of the port. For example, a port  400  shown in  FIG. 10  has a flange  404  extending from a port body  402  thereof only around orifices  406 , instead of completely surrounding the port  400 . In addition, the port may be further reduced in size by reducing the number of orifices  406  to a minimum number necessary to stabilize the port  400 .  
         [0021]     As described above, the shuttle  104  is releasably held in place within the port body  102  by the retaining elements  150 , 152  to provide a passage  120  to the inside of the body (e.g., to the vascular system) when the PASV  110  is open and to seal the passage  120  when the PASV  110  is closed. As would be understood by those skilled in the art, the passage  120  is placed in fluid communication with the vascular system (e.g., a blood vessel) via a catheter inserted into a distal end  160  of the shuttle  104  via the catheter channel  112 . The distal end  160  of the shuttle  104  interfaces with a shuttle seat  162  of the port body  102  to form a fluid seal when the shuttle  104  is in place within the port body  102 .  
         [0022]     The PASV body  110  selectively provides access to the flow passage  120 , and thus to the vascular system when desired and seals that passage when not in use. As would be understood by those skilled in the art, the PASV body  110  may, for example, include a valve membrane  156  sealing the passage at all times that a fluid pressure exerted thereagainst is no greater than a threshold pressure passes therethrough. When the pressure exerted against the valve membrane  156  is greater than the threshold pressure, the valve membrane  156  opens to permit fluid flow therethrough. The shuttle  104  preferably comprises an attachment  163  conforming to a conventional fluid connection used to couple the PASV body  110  to an external flow passage. During use to inject fluids, a fluid connection is made via the attachment  163  and fluid is injected through the connection at a pressure greater than the threshold pressure to open the valve membrane  156  so that the fluid passes through the PASV body  110  into the fluid conduit  120  to reach a target site (e.g., a body lumen into which a distal end of a catheter attached to the conduit  120  is inserted). As would be understood by those skilled in the art, flow through the PASV body  110  may be reversed to remove fluids by applying to the connection a negative pressure greater in magnitude than the threshold pressure.  
         [0023]     As described above, the shuttle  104  preferably also comprises a guidewire valve bypass  108  allowing a guidewire to be inserted into a catheter attached to the catheter channel  112  without damaging the valve  110 . Those skilled in the art will understand that the guidewire may be used to aid in implanting the catheter at a desired location and to otherwise assist in the correct positioning of components of the system within the body. The guidewire valve bypass  108  may also be used to insert a guidewire to the target site during replacement of a defective or damaged catheter to facilitate the positioning of a replacement catheter at the target site as more fully described below. A cap is inserted over the guidewire valve bypass  108  to seal it when not in use to prevent contaminants from reaching the vascular system.  
         [0024]     In a different embodiment, the shuttle  104  may be designed without the guidewire valve bypass  108 . In this embodiment, the valve body  110  allows a guidewire to be passed therethrough without sustaining damage. For example, the membrane of a PASV valve may be reinforced to improve its ability to withstand repeated entry by the guidewire (e.g., when the port  100  and the catheter are implanted). By omitting the guidewire valve bypass it is possible to manufacture a percutaneous port having smaller dimensions, which is easier to implant.  
         [0025]     One advantage of the port  100  according to the invention is that the catheter attached to the catheter channel  112  may be replaced without removing the port and without performing a complex surgical procedure. In case of failure or other damage to the catheter, a guide wire may be inserted through the catheter to the target site via the guide wire valve bypass  108 . The shuttle  104  may then be removed from the port body  102  over the guide wire to allow free access to the proximal end of the catheter via the now empty cavity  114 . The catheter may then be removed through the catheter channel  112  over the guide wire without disturbing the port body  102 . A new catheter may then be reinserted over the guide wire through the catheter channel  112  to the target site. The guide wire may then be removed and the shuttle  104  may be repositioned in the cavity  114  and attached to the proximal end of the catheter to form a fluid tight seal with the shuttle seat  162  and with the catheter. A locking mechanism is preferably provided on the shuttle seat  162  to lock the catheter in place after insertion.  
         [0026]     In the exemplary embodiment shown, the cavity  114  of the port body  102  is sealed by a cover  106  which prevents contaminants from entering the port  100 . For example, the cover  106  is preferably securely locked in place over the port body  102  when not in use to prevent inadvertent removal therefrom. The port body  102  according to this exemplary embodiment comprises a lip  148  cooperating with protrusions  166  of the cover  106  to form a snap or frictional attachment thereto with the lip  148  substantially flush with the skin  146  of the patient, so that an upper surface  142  of the cover  106  protrudes only minimally above a surface if the skin. This feature makes the port  100  more easily tolerated by the patient and less likely to be inadvertently dislodged during normal patient activity. As would be understood, additional internal snaps or ridges  154  may be formed on the port body  102  to better retain the cover  106  in place.  
         [0027]     A relatively large free space is formed between the cavity  114  of the port body  102  and the cover  106 . This free space may preferably be filled with an antibacterial agent residing in the port  100  between uses, to help prevent the establishment of an infection. Thus the cover  106 , which also acts as a fluid seal, and a gasket seal between the cover  106  and port body  102 , act to prevent the antibacterial agent from leaking out of the port  100  and onto the patient. The valve  156  of the PASV valve body  110  and the cap covering the guidewire valve bypass  108  prevent the antibacterial agent from reaching the bloodstream.  
         [0028]      FIGS. 5 and 6  show two additional embodiments of a percutaneous port according to the invention. The port  200  of  FIG. 5  comprises a port body  202  including an opening  208  connected to a catheter channel  204 . In this exemplary embodiment, a catheter enters the port body  202  through the catheter channel  204  so that a fluid connection may be made between the catheter and an external fluid conduit, to infuse and/or remove fluids from the patient. As described above, a removable shuttle including a selective sealing mechanism such as a PASV  206  is removably insertable within the opening  208  to seal the catheter channel  204  when not in use. A seal  212  extends from the distal end of the shuttle which sealingly engages the opening  208  without requiring any additional components.  
         [0029]     The shuttle of the embodiment shown in  FIG. 5  includes a valve  206  which may be easily removed and exchanged for a new one if it becomes damaged or clogged. The PASV valve  206  may be replaced without removing the entire port  200 , and without the need to perform a surgical procedure. The procedure is simplified because the seal  212  is a part of the PASV  206  so that the surgeon does not have to manipulate an additional sealing component to assemble the port  200 . The catheter may still be withdrawn through the opening  208 .  
         [0030]      FIG. 6  shows another embodiment of the port according to the invention. In this case, the valve  256  of the percutaneous port  250  does not include an integral sealing element, but instead uses a separate sealing element. For example, a carrying unit  260  fits around the valve  256  to form a fluid tight seal between the valve  256  and the opening  258  leading to the catheter and a catheter channel  254  allows the catheter to partially enter into the port body  252  of the port  250 . The addition of the carrying unit  260  provides a sealing fit with the port body  252  and allows the use of a valve  256  of conventional design. The use of conventional components, in turn, provides a simpler and less expensive port  250 .  
         [0031]     As described above, the cover of the percutaneous port according to the invention is adapted to prevent its inadvertent removal. The locking mechanism for the cover thus is designed to resist detachment due to impact, handling by the patient and/or from movement and forces to which it is exposed during normal patient activity. Various exemplary designs of the cover according to the invention are shown in  FIGS. 7, 8  and  9 .  FIG. 7  shows a percutaneous port  300  comprising a port body  302  closed by a cover  304 . The cover  304  has a mechanical locking mechanism actuated by manually moving a tab  306  about a pivot point  310 . For example, the tab  306  may be linked to prongs  308  that extend into a groove or indentation  312  to lock the cover  304  in place. The tab  306  may be held into the locked position by an overcenter linkage, until raised manually by the user.  
         [0032]     As shown in  FIG. 8 , a port  350  according to another embodiment is shown in  FIG. 8  includes a cover  354  that releasably attachable to the port body  352  by a mechanical latch. For example, the cover  354  includes a sliding lock/release actuator  356  which, when actuated, moves a mechanical linkage that activates locking protrusions  358  to engage slots  360  formed on the port body  352 . The actuator  356  may be thumb operated by the user to slide between locked and unlocked positions.  
         [0033]     As shown in  FIG. 9 , a port  380  according to a further embodiment includes a port cover  384  closing a port body  382 . The port cover  384  has no moving parts, but instead releasably locks on the port body  382  by frictional engagement with grooves  390 . A grasping element  386  may optionally be provided to allow a user to grasp the cover  384  and to exert a force thereto sufficient to overcome the frictional engagement with the grooves  390 . The port cover  384  can be screwed in to the port body  382  as well. The cover  384  of the exemplary port  380  is inexpensive and relatively easy to manufacture because of the absence of moving parts.  
         [0034]     The percutaneous port according to the present invention may also be constructed with dual lumens allowing, for example, for simultaneous inflow and outflow of fluids via a dual lumen catheter. As shown in  FIG. 11 , a dual lumen percutaneous port including a dual lumen shuttle  500  includes inflow and outflow fluid passages  506 ,  508 , respectively, extending therethrough between an  510  inlet and an outlet  512 , respectively, each of which is adapted to sealingly mate in fluid connection with respective catheters. As described above, the shuttle  500  may be connected to a percutaneous port during operation, and may be detached and removed from the percutaneous port to replace one or both catheters, without having to perform a complex surgical procedure.  
         [0035]     In the exemplary embodiment shown, each of the fluid passages  506 ,  508  has a proximal opening into a corresponding one of a pair of valve bodies  514 ,  516  each of which is adapted to seal the catheter when fluids are not being injected or withdrawn therefrom with each of the valve bodies  514 ,  516  comprising, for example, a PASV valve membrane  502 ,  504 , respectively, designed to allow the passage of a guidewire therethrough without sustaining damage. Accordingly, it is not necessary to provide one or more guidewire valve bypass ports and the shuttle  500  may be made smaller and more compact. The side by side orientation of the valve bodies  514  and  516  also promotes a compact size, which results in simpler implantation and use of the port. In other embodiments, a guidewire valve bypass similar to that shown in  FIG. 1  may be included to further reduce damage to the valve membranes  502 ,  504 .  
         [0036]     Furthermore, as would be understood by those skilled in the art a gasket seal (not shown) is included between the port bodies and the covers of the various embodiments to aid in preventing antibacterial agent from leaking from the port bodies.  
         [0037]     The present invention has been described with reference to specific embodiments, and more specifically to a percutaneous vascular access port. However, other embodiments may be devised that are applicable to other medical devices and procedures, such as accessing other body lumens and drainage of fluids from the body. Accordingly, various modifications and changes may be made to the embodiments, particularly with regard to dimensions and materials, without departing from the broadest spirit and scope of the present invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense.