Abstract:
A catheter tip for an infusion catheter has a hollow tubular shaped base member with a pair of annular shaped inflation balloons positioned in parallel on the base member. A plurality of microfibers are mounted on the cylindrical surface section between the balloons. The microfibers are in fluid communication with the lumen of the catheter tip. In operation, the catheter tip is advanced into the vasculature of a patient and to a site in a small vein that is near the target tissue for infusion. The balloons are then inflated to anchor the catheter tip, and fluid medicament is infused through the microfibers. In an alternate embodiment, the microfibers can be replaced with at least one orifice.

Description:
[0001]    This application is a continuation-in-part of application Ser. No. 12/113,742, filed May 1, 2008, which is currently pending. The contents of application Ser. No. 12/113,742 are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention pertains generally to systems and methods for infusing fluid medicaments into tissue in the vasculature of a patient. More particularly, the present invention pertains to in-dwelling catheters. The present invention is particularly, but not exclusively, useful as a system and its method of use wherein the catheter tip is anchored in a small vessel (e.g. vein) of the vasculature to infuse a fluid medicament from the lumen of the vessel, and through the wall of the vessel, into target tissue surrounding the vessel. 
       BACKGROUND OF THE INVENTION 
       [0003]    Heretofore, when organs inside the body have required therapeutic treatment, the typical practice has been to orally or intravenously administer medicaments. Typically, these medicaments (i.e. drugs) transit to and from the target organ through the body&#39;s blood stream. In many instances, however, this unnecessarily exposes the entire body to the effect. And, it can be quite problematic due to the fact an efficacious concentration of the fluid medicament in one area of the body can be toxic in others. 
         [0004]    Not infrequently, it happens that only a portion of an organ&#39;s tissue requires therapeutic treatment. Moreover, it may be desirable, and indeed necessary, to treat this portion of organ tissue with relatively high concentrations of a fluid medicament for an extended period of time. An effective way to do this is by infusing a fluid medicament directly into extracellular fluid in the target tissue. Fortunately, with such infusions the effect can remain somewhat localized as the medicament diffuses down its concentration gradient from the site of application to more distant sites in the tissue. Further, the effect may even be limited to only the particular organ and, thus, effectively isolated from the blood stream. Nevertheless, under such circumstances it is necessary that the administration of the fluid medicament be properly controlled. 
         [0005]    Various types of catheter systems are commercially available for use in the vasculature of a patient. Typically, each catheter system is specially designed to perform a particular function, or functions, for a specific application. Of particular interest for the present invention are indwelling catheters that can remain in situ in the venous system of a patient&#39;s vasculature for extended periods of time. 
         [0006]    It is also known that a fluid medicament, when confined to a particular space (volume) within a vessel of the vasculature, will infuse through the vessel wall and into the surrounding tissue. Preferably, the space will be relatively small, and can be established to not adversely affect blood flow through the vasculature. In the event, there are several such locations in the vasculature where a relatively small vein (e.g. left atrial) is adjacent to, or is surrounded by, target tissue that will benefit from the infusion of a fluid medicament. 
         [0007]    In light of the above, it is an object of the present invention to provide a transvenous soaker catheter, and its method of use, that is able to selectively deliver substances (i.e. fluid medicaments) at adjustable concentrations into the extracellular fluid, at a particular location in a target organ. Another object of the present invention is to provide a transvenous soaker catheter that effectively limits the exposure of an administered fluid medicament to targeted organ tissue. Still another object of the present invention is to provide a transvenous soaker catheter, and its method of use, that minimizes system toxicity while allowing the local administration of much higher concentrations of a drug (i.e. fluid medicament) in a predetermined area. It is an object of the present invention to provide a device that will create a space within the vasculature of a patient where a fluid medicament can be introduced for subsequent infusion into target tissue surrounding the space. Another object of the present invention is to provide a fluid flow device that will effectively allow a fluid medicament to be infused into target tissue from inside a vessel in the vasculature of a patient. Still another object of the present invention is to provide a catheter tip for an infusion catheter that is easy to use, is relatively simple to manufacture, and is comparatively cost effective. 
       SUMMARY OF THE INVENTION 
       [0008]    In accordance with the present invention, a system for infusing a fluid medicament into a volume of tissue includes a catheter having a proximal end and a distal end. A source of the fluid medicament is attached in fluid communication with the proximal end of the catheter, and a controller is provided to establish a predetermined fluid flow rate for the flow of the fluid medicament from the source to the catheter. Also, the controller includes a timer that allows control over the time duration of the fluid medicament flow from the source to the catheter. 
         [0009]    An infusion member is affixed to the distal end of the catheter. Preferably, the infusion member is an elongated needle like structure that extends in a distal direction from the distal end of the catheter. For one embodiment of the infusion member, it is formed with at least one laser pin hole. In another embodiment, at least one biodegradable fiber extends from the infusion member. For either embodiment, after the fluid medicament has been pumped through the catheter, the fluid medicament leaves the infusion member though the pin hole(s) or the biodegradable fiber(s). 
         [0010]    As envisioned for the present invention, the infusion member can be associated with a stabilizing element at the distal end of the catheter. For example, a helical wire (i.e. cork-screw shaped wire) can be attached to the distal end of the catheter to surround the infusion member. As another example, the infusion member itself can be helical shaped. 
         [0011]    In the operation of the present invention, the intravenous soaker catheter is maneuvered through the venous system until the infusion member is positioned at an intended target site. The infusion member is then embedded into tissue at the target site, and stabilized. In many instances, the length of the infusion member will be sufficient to stabilize it at the target site. On the other hand, as indicated above, stabilization can also be accomplished by screwing a helical stabilization wire that is mounted on the catheter, into tissue at the target site. The infusion member itself may also be helical shaped and, thus, it can be similarly screwed into tissue at the target site for stabilization. 
         [0012]    Once the catheter has been properly positioned, and the infusion member properly stabilized, the controller can be activated. Specifically, in accordance with instructions from the controller, the fluid pump can be operated to infuse fluid medicament from the fluid source into extracellular fluid in the target volume of fluid. This can be done at a predetermined fluid flow rate, for a predetermined time duration. As envisioned for the present invention, the infusion of fluid medicament can be continuously, or periodically, accomplished over extended periods of time (e.g. greater than five minutes). 
         [0013]    In accordance with another aspect of the present invention, an infusion catheter includes a tip that can be anchored in the vasculature of a patient. Preferably, the tip is anchored in a small vein of the vasculature (e.g. left atrial), and a fluid medicament is released from the fluid delivery device located at the tip. Once released, the fluid medicament is then infused into target tissue in the proximity of the catheter tip. 
         [0014]    Structurally, the catheter tip of the infusion catheter for the present invention has a hollow, tubular shaped base member. Also, there is an annular shaped, inflatable balloon that is mounted on the outer surface of the base member at its distal end. Likewise, an annular shaped, inflatable balloon is mounted on the outer surface of the base member at its proximal end. The two mounted balloons are separated from each other by a distance “d” to establish a cylindrical surface section between them. With this configuration, the proximal end of the base member (i.e. catheter tip) is affixed to the distal end of the infusion catheter, to place their respective lumens in fluid communication with each other. 
         [0015]    For a preferred embodiment of the fluid delivery device for the present invention, a plurality of microfibers are mounted on the cylindrical surface section of the base member (catheter tip) for fluid communication with its inner lumen. For this embodiment (i.e. microfibers), the distal end of the base member may either be closed or patent, as desired. In an alternate embodiment of the fluid delivery device for the present invention, microfibers need not be used. Instead, an orifice can be formed at the distal end of the base member through which the fluid medicament can enter the lumen of the vessel where the base member is anchored. 
         [0016]    Extracorporeal components for use with the catheter system of the present invention include a source of the fluid medicament that is to be infused into the patient. Also included is an infusion pump for pumping the fluid medicament from the source, through the infusion catheter, and out of the fluid delivery device at the catheter tip. Further, such a system may include a controller that is electronically connected to the infusion pump for establishing a fluid flow rate for the fluid medicament through the system. Additionally, a selector can be incorporated with the controller to selectively change the fluid flow rate between a steady chronic flow rate and a pulsed flow rate. 
         [0017]    In an operation of the present invention, the catheter tip is advanced through the vasculature to a site near the target tissue. The balloons are then inflated to anchor the catheter at the site. Typically, the target tissue will be near a vessel, such as a small vein (e.g. left atrial), and the inflated balloons will urge against the walls of this vessel to anchor the catheter tip at the site. Once the catheter tip has been anchored in the vasculature, the infusion pump can be activated to infuse the fluid medicament into the target tissue. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0019]      FIG. 1  is a schematic view of a system for an indwelling, transvenous soaker catheter in accordance with the present invention; 
           [0020]      FIG. 2  is a cross section view of tissue adjacent a vein in the venous system with a soaker catheter of the present invention operationally embedded into the tissue; 
           [0021]      FIG. 3  is an alternate embodiment of the infusion member for a soaker catheter in accordance with the present invention; 
           [0022]      FIG. 4  is a view of an infusion member with a helical screw for stabilizing the infusion member in the venous system; 
           [0023]      FIG. 5  is another alternate embodiment showing the infusion member formed as a helical screw; 
           [0024]      FIG. 6  is a schematic of an alternate system for an indwelling, transvenous soaker catheter; 
           [0025]      FIG. 7  is a schematic view of the catheter tip of the alternate system shown positioned in the vasculature of a patient; and 
           [0026]      FIG. 8  is a cross-section view of the catheter tip of the alternate system as seen along the line  8 - 8  in  FIG. 7 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Referring initially to  FIG. 1 , a system for a transvenous soaker catheter in accordance with the present invention is shown and is generally designated  10 . As shown, the system  10  includes an indwelling catheter  12  that has a proximal end  14  and a distal end  16 . The system  10  also includes a source  18  of a fluid medicament (i.e. drug), and a pump  20  that can be used to pump the fluid medicament from the source  18  through a fluid line  22 . In order to control the flow of this fluid medicament, the system  10  further includes a controller  24  that is electronically connected to the pump  20 . In this combination, the controller  24  can be preprogrammed to operate the pump  20  according to a predetermined schedule. Specifically, this schedule can include the fluid flow rate of the fluid medicament being pumped by the pump  20 , as well as the time duration of the fluid flow. 
         [0028]    Still referring to  FIG. 1 , it will be seen that the fluid line  22  is connected in fluid communication with the proximal end  14  of the catheter  12 . Thus, fluid medicament from the source  18  can be pumped directly to the catheter  12  in accordance with preprogrammed instructions from the controller  24 .  FIG. 1  also shows that the system  10  includes an infusion member  26  that is affixed to the distal end  16  of the catheter  12 . For the purposes of the present invention, the infusion member  26  is preferably an elongated hollow needle  28  that is formed with a plurality of holes  30 . As shown, the holes  30  are preferably aligned along the axis of the hollow needle  28 . For its use in the system  10 , the hollow needle  28  can be made of stainless steel and the holes  30  can be created using well known laser techniques. 
         [0029]    Turning now to  FIG. 2 , the infusion member  26  is shown in its intended operational environment. Specifically,  FIG. 2  shows the catheter  12  positioned in the lumen  32  of a vein  34 . In this instance, the infusion member  26  of the system  10  has been embedded into the tissue  36  of an organ in the human body (not shown). Further, the tissue  36  in  FIG. 2  is shown to anatomically comprise a plurality of cells  38  that are surrounded by extracellular fluid  40 . As will be appreciated by the skilled artisan, although the discussion here considers the tissue  36  to be organ tissue, it is to be appreciated that other types of tissue (e.g. muscular tissue) may also be the intended target tissue  36  for therapeutic intervention with the system  10 . 
         [0030]    An alternative to the infusion member  26  (shown in  FIGS. 1 and 2 ) is an infusion member  42  as shown in  FIG. 3 . Like the infusion member  26 , infusion member  42  incorporates an elongated hollow needle  28 . Instead of holes  30 , however, the infusion member  42  incorporates biodegradable fibers  44  that are positioned along the length of the needle  28 . For use in the system  10 , the biodegradable fibers  44  need to be permeable to the fluid medicament that is to be used and, thus, they are in fluid communication with the source  18 . 
         [0031]    Additional alternate embodiments of components for use with the system  10  are shown in  FIGS. 4 and 5 . Specifically,  FIG. 4  shows a helical shaped wire  46  that is affixed to the distal end  16  of the catheter  12 . As intended for the system  10 , this helical shaped wire  46  can be screwed into the target tissue  36  to provide additional stabilization for the infusion member  26  during operation of the system  10 . Another alternative is shown in  FIG. 5 . There, an infusion member  26 ′ is shown configured with a substantially helical shape. In this configuration, the infusion member  26 ′ can, itself, be screwed into the target tissue  36  for additional stabilization. 
         [0032]    In the operation of the system  10  of the present invention, a fluid medicament is selected for use and provided as the fluid source  18 . Controller  24  is then programmed for the controlled operation of the pump  20 . Specifically, a fluid flow regimen is established for the pump  20 , with a prescribed fluid flow rate, and scheduled operational time durations (periodic or continuous). Then, with an infusion member  26  affixed to its distal end  16 , the catheter  12  is advanced through the venous system of a patient until the infusion member  26  has been positioned adjacent target tissue  36  at the selected site. The infusion member  26  is then embedded into the target tissue  36  (see  FIG. 2 ), by methods well known in the pertinent art. Lastly, the controller  24  is activated. 
         [0033]    As indicated in  FIG. 2 , operation of the system  10  causes an infused medicament  48  to mix with extracellular fluid  40  in the target tissue  36 . Importantly, the concentration of fluid medicament in source  18 , as well as the rate, and the time duration of fluid flow provided by pump  20  are controllable. Consequently, the concentration gradient of infused medicament  48  in the target tissue  36  is also controllable. 
         [0034]    Referring now to  FIG. 6  an alternate system for an indwelling, transvenous soaker catheter is shown and is generally designated  100 . In detail, the system  100  includes an infusion catheter  102  having a proximal end  104  and a distal end  106 . Further, the system  100  includes a source of fluid medicament  18  that is connected via a pump  20  to the proximal end  104  of the system  100 . As shown, a computer/controller  108  is connected with the pump  20  for selectively operating the pump  20 . Also, the computer/controller  108  is connected with an inflator  110  for selectively operating the inflator  110 . Like the pump  20 , the inflator  110  is connected in fluid communication with the proximal end  104  of the infusion catheter  102 . 
         [0035]    At the distal end  106  of the infusion catheter  102 ,  FIG. 6  shows there is a catheter tip that is generally designated  112 . More specifically, the catheter tip  112  includes a tubular-shaped body member  114  that has a proximal end  116  and a distal end  118 .  FIG. 6  also indicates that the proximal end  116  of the body member  114  is connected in fluid communication with the distal end  106  of the infusion catheter  102 , and that an inflatable balloon  120  is mounted on the proximal end  116  of the catheter tip  112 . Also,  FIG. 6  shows that an inflatable balloon  122  is mounted on the distal end  118  of the catheter tip  112  and aligned substantially parallel to the inflatable balloon  120 . As shown for the system  100 , the proximal inflatable balloon  120  is located on the catheter tip  112  at a distance “d” from the distal inflatable balloon  122 . 
         [0036]      FIG. 7  shows that, for a preferred embodiment of the system  100 , a plurality of microfibers  44  can be mounted on the body member  114 , between the inflatable balloons  120  and  122 . Also,  FIG. 8  shows an alternate embodiment for the system  100  wherein an infusion port  124  is formed at the distal end  118  of the catheter tip  112 . For these embodiments, respectively, the microfibers  44  ( FIG. 7 ) and the infusion port  124  ( FIG. 8 ) are each in fluid communication with the lumen  126  that runs the length of the infusion catheter  102  and the catheter tip  112 . It is to be further appreciated that in another embodiment of the system  100 , the infusion port  124  may be closed. If so, the embodiment of the system  100  that incorporates the microfibers  44  (shown in  FIG. 7 ) will be used. Still referring to  FIG. 8 , it will be seen that an inflation lumen  128  is provided for the proximal inflatable balloon  120 , and that an inflation lumen  130  is provided for the distal inflatable balloon  122 . Both inflation lumen  128  and inflation lumen  130  are connected in fluid communication with the inflator  110 . Accordingly, inflation balloon  120  and inflation balloon  122  can be selectively and individually inflated by the computer/controller  108  as desired by the operator. 
         [0037]    In an operation of the system  100 , the catheter tip  112  is advanced through the vasculature of a patient (not shown) until it has been advanced as far as possible. An example of a typical route for the advancement of the catheter tip  112  in the vasculature begins in the subclavian vein, with a subsequent advancement through the right atrium, the coronary sinus, and into the left atrial vein. This, however, is only exemplary, as the system  100  may be used in any organ, and the catheter tip  112  can be wedged into a suitably sized vein at any desired location. In the event, once the catheter tip  112  has been positioned at a site  132  in the vasculature (e.g. see  FIG. 7 ), the inflatable balloons  120  and  122  can be inflated in accordance with instructions from the computer/controller  108 . Preferably, both of the balloons  120  and  122  are inflated in order to assure a firm anchorage for the catheter tip  112  and to prevent fluid backwash. The present invention, however, also envisions the possible inflation of only one of the balloons  120  or  122 . 
         [0038]    Once the catheter tip  112  has been positioned as desired in the vasculature of a patient, the computer/controller  108  is activated to operate infusion pump  20  for an infusion of medicament from the source  18 . As envisioned for the present invention, this infusion of fluid medicament will be made through either the microfibers  44 , or through the infusion port  124 , or simultaneously through both. Further, in accordance with pre-programmed instructions, the infusion of medicament may be either at a steady chronic rate or it can be pulsed with intermittently high fluid flow rates. 
         [0039]    While the particular Transvenous Soaker Catheter Using Microfibers as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.