Patent Publication Number: US-2006015089-A1

Title: Catheter and method of fluid removal from a body cavity

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application is a divisional application claiming the benefit under 35 U.S.C. §§ 120 and 121 of U.S. application Ser. No. 10/172,160 filed on Jun. 14, 2002, which claims domestic priority under 35 U.S.C. § 119(e) to provisional Patent Application No. 60/370,558 filed Apr. 4, 2002, all of which are hereby incorporated by reference. 
    
    
     BACKGROUND  
      The present invention relates to devices that permit repeated access to the peritoneal or thoracic cavities. More particularly, the invention relates to a peritoneal and thoracic cavity port catheter.  
      Certain medical conditions (e.g., ovarian cancer) are treated by infusing a body cavity with a fluid medical preparation through a catheter with one or more infusion holes at a distal end thereof and with an access port or other such device at a proximal end thereof.  
      In the case of ovarian cancer, the radioactive isotope P 32  is administered in a fluid medium infused into the peritoneal cavity, in which the patient&#39;s ovaries are located. When ovarian cancer metastasizes or spreads from the ovaries, the cancer cells simply fall off of the ovaries and spread around the peritoneal cavity, but generally do not enter the blood stream. Therefore, a therapy, which floods the peritoneal cavity with P 32 , is effective, without unnecessarily exposing the patient to radioactivity in undesired areas. However, ovarian cancer cells, having somewhat defective cell membranes, leak fluids, called ascites, into the peritoneal cavity. Treatment of ovarian cancer includes removal of this fluid. The procedure for doing so typically uses the same catheter through which the infusion is performed, and takes about four hours, requiring hospitalization, and is performed about once a week.  
      Because conventional infusion catheters are optimized for infusion, they can only be used to remove fluids from the peritoneal cavity very slowly, resulting in the long, periodic hospitalization for ovarian cancer patients.  
      There are similar needs under some circumstances to have access to the thoracic cavity or other body cavities, and current devices for obtaining such are similarly limited.  
     SUMMARY OF THE INVENTION  
      In accordance with aspects of an embodiment of the invention, there may be provided a catheter, comprising a catheter body having a wall defining a lumen therein and having plural holes defined through the wall in a pattern which prevents loculation, migration and blockage of a fluid flow through the lumen, the catheter body having a tissue-puncture resistant shape; and a port having a reservoir capable of multiple needle accesses. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      In the figures, in which like reference designations indicate like elements:  
       FIG. 1  is a top view of a catheter and port embodying aspects of the invention;  
       FIG. 2  is a cross sectional detail view of the catheter of  FIG. 1 , taken along line  1 - 1 ;  
       FIG. 3  is a perspective view of the catheter of  FIG. 1 ;  
       FIG. 4  is a top view of an alternate port configuration embodying aspects of the invention;  
       FIG. 5  is a top view of an alternate catheter configuration embodying aspects of the invention;  
       FIG. 6  is a top view of yet another alternate catheter configuration embodying aspects of the invention;  
       FIG. 7  is a top view of an alternate catheter and port configuration embodying aspects of the invention;  
       FIG. 8  is an end view of the catheter of  FIG. 7 ;  
       FIG. 9  is a top view of the catheter of  FIGS. 7-8 , extended by a pusher rod shown in phantom;  
       FIG. 10  shows a cross section of a patient&#39;s peritoneal cavity, into whose wall another configuration of port and catheter has been implanted;  
       FIG. 11  is a side view of the distal end of the catheter body of  FIG. 10 ;  
       FIG. 12  is an end view of the catheter body of  FIG. 10 ;  
       FIG. 13  is a perspective view of the port and catheter connection of the embodiment of  FIG. 10 ;  
       FIG. 14  is a cross-sectional side view of a removable core access needle used in various embodiments;  
       FIG. 15  is a side view of a catheterless plug;  
       FIGS. 16, 17  and  18  are side, top and front views, respectively, of an alternate port design;  
       FIG. 19  is a side view of a combined catheter shape;  
       FIGS. 20 and 21  are end and side views, respectively, of an alternate combined catheter shape; and  
       FIGS. 22 and 23  are side and top views, respectively, of a port design having a right-angle outlet. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
      In accordance with some embodiments of the present invention, a method and apparatus is provided for removal of fluids from a patient&#39;s body, for example draining fluids from a body cavity between multiple drug infusion operations (e.g., during the entire duration of treatment).  
      Embodiments of aspects of the invention may include a catheter or a catheterless plug having a catheter body and an access port, and a method of extracting fluid from a body cavity. As explained more fully below, the catheterless plug has a body resembling a catheter body, but which can comprise a fully integrated unit. References below to the catheter body apply to the body of the catheterless plug, as well, except where differences are explicitly mentioned.  
      The catheter body should preferably have a shape that is unlikely to undesirably puncture or injure tissue or organs encountered in or about the body cavity to be drained. The shape of the catheter body, together with the placement of one or more fluid extraction holes in a wall of the catheter body should preferably be such as to avoid the formation of pockets (referred to by those skilled in this art as loculation) and/or to avoid creating a fluid flow that would cause migration of the catheter body, or of tissue or debris, that could block the extraction holes. For example, the extraction holes can be positioned in a protected region of the catheter body, as described below.  
      The catheter port should preferably be implantable subcutaneously, and/or capable of sufficient extraction needle passages to complete a course of treatment without replacement.  
      The invention is now illustrated in further detail with reference to some embodiments thereof. In the following description the illustrative example of extracting fluid from the peritoneal cavity is used. However, it should be understood that the invention may be employed in connection with treatments requiring the extraction of fluid from the thoracic cavity or another body cavity.  
      One aspect of the invention is illustrated in connection with a catheter  10  including a catheter body  100  ( FIGS. 1-3 ) having a lumen ( FIG. 2, 200 ) that may be closed off at the distal end  101 , i.e., having no end hole. This embodiment includes plural holes  102  covering a combined surface area suitable for withdrawing fluid, substantially without clogging. Thus, when the catheter  10  is used to extract fluid from the peritoneal cavity, there is no large suction through a dominant single point which could attract occluding masses to migrate to the dominant single point or could attract the catheter itself to migrate into a position where a dominant single point is occluded. Optionally, in another embodiment, an end hole can be provided at the distal end  101  of catheter body  100 , together with one or more other holes  102 , provided neither a hole  102  nor the optional end hole contributes such a surface area, and consequently large fluid flow, as to induce loculation or migration of the catheter body  100 .  
      In order to provide more room for holes  102 , the catheter body  100  of this embodiment is quite long. One danger inherent in implanting a catheter  10  in many body cavities is the risk of perforating or puncturing an organ, membrane, or other tissue unintentionally. The risk is especially large when a long catheter body  100  is implanted into a closed cavity such as the peritoneal cavity, with the expectation that the catheter will bunch up like spaghetti.  
      In the embodiment of  FIGS. 1-3 , the catheter body  100  is a self-coiling type to facilitate insertion of such a relatively long catheter into the body. This may be achieved by means known to the skilled practitioner such as molding the catheter body  100  in a desired coil configuration, molding the catheter body  100  on a coiled strength member such as a wire, etc. The coil may be flat, a straight-sided helix, a conical helix, etc.  
      The embodiment of  FIGS. 1-3  employs a flat coil pigtail configuration, although other coil configurations, as well as configurations that avoid perforation or puncture using other shapes, as explained below, are possible.  
      As stated above, the holes  102  should be positioned to avoid contact with adjacent tissues or occluding masses. The holes  102  of this embodiment are positioned on the inner curve  107  of the coil so as to avoid contact between the holes  102  and adjacent tissues. The outer curve  108  and the sides  109  can be devoid of holes. Thus, the holes  102  are in a protected region of the catheter body. As used herein, “inner curve” refers to that part of the surface of a coil-shaped catheter body  100  facing a central axis of the coil of the catheter body  100 . Also as used herein, “outer curve” is that part of the surface of the coil-shaped catheter body  100  facing away from a central axis of the coil of the catheter body  100 . Finally as used herein, “sides” are surfaces of the coil-shaped catheter body  100  adjacent to both the inner curve  107  and outer curve  108  and joining them.  
      As mentioned, other shapes can also avoid puncturing adjacent tissues, organs and membranes, while distributing holes  102  to prevent loculation, migration or occlusion. As shown in  FIG. 5 , an alternate embodiment of a catheter  500  has a catheter body  501  with a shape such as a simple helix or corkscrew, that avoids punctures. Holes  102  are disposed on the inner curve  502  of the catheter body  501  to avoid contact between the holes  102  and adjacent tissues. Again, the holes  102  are located in a protected region of the catheter body. This catheter  500  and the catheter  10  of  FIGS. 1-3  can optionally include an end hole (not shown) at the distal end  503  provided the area of the end hole is properly balanced against the areas of the holes  102 .  
      Another catheter body shape possessing desirable characteristics of avoiding punctures, loculation, migration and occlusion is shown in  FIG. 6 . In this example, catheter body  600  has a T-bar shape. The terminuses  601  may be closed or may optionally include end holes (not shown) at the terminuses  601 .  
      Yet another suitable catheter body shape is shown in  FIGS. 7-9 . This catheter body  700  has what is referred to as a “tulip” shape. The surfaces of the tulip “petals”  701  can be opened into holes  702 . The center  703  of the tulip may be a closed end nipple  704 , which captures a pusher rod  705  by which the catheter body  700  is advanced during implantation. When the pusher rod  705  is extended, the end of the catheter body  700  stretches, collapsing the tulip petals  701  as shown in  FIG. 9 . When the pusher rod  705  is withdrawn, after implantation, the tulip petals  701  expand as shown in  FIGS. 7 and 8 . This configuration can be shorter then those of  FIGS. 1-3  and  5 - 6  because the shape of petals  701  permits holes  702  to have a large surface area compared to holes  102 .  
      Another suitable arrangement for the catheter body that prevents blockage, puncture or loculation is shown in  FIGS. 10-12 . This embodiment has a short body  1001  terminating in one or more fluid extraction holes  1002 . The fluid extraction holes  1002  are surrounded by a spherical cage  1003  that prevents organs, e.g. the bowels  1004 , or debris from blocking the extraction holes  1002 . The cage  1003  may have other shapes, but a spherical cage  1003  presents no sharp edges or steps that are likely to cause problems during implantation or removal. Because the cage  1003  surrounds the fluid extraction holes  1002 , the extraction holes  1002  are in a protected region of the catheter body.  
      The spherical cage  1003  of this embodiment can be formed of plastic, metal, or any other suitable material. If formed of plastic, the cage  1003  can be molded integrally with the body  1001  of the catheter, in the expanded spherical shape shown in  FIGS. 10-12 . If formed of metal, the cage  1003  can be preformed, also in the expanded spherical shape shown in  FIGS. 10-12 . The metal can be Nitinol or another so-called “memory metal” which can be alternately stowed or deployed, for example by alternate application of room ambient temperature and of the patient&#39;s own body heat. A metal spherical cage  1003  would also be formed integrally with and molded into the plastic of catheter body  1001 . In an alternative method of stowing and deploying the device, as in the case of the tulip design described above in connection with  FIGS. 7-9 , the spherical shape can be collapsed by a pusher rod engaging an end tab  1005  during insertion and extraction. The pusher rod is withdrawn completely from the catheter body while the catheter is in situ in a patient&#39;s body.  
      The catheter body ( FIG. 1, 100 ;  FIG. 5, 501 ;  FIG. 6, 600 ,  FIG. 7, 700 ,  FIG. 10, 1001 ) may be constructed of any suitable materials, using any suitable methods. Holes  102 ,  702 , where applicable, may be molded into the catheter or formed by any other suitable technique, e.g., laser drilling, which can produce holes suitable for rapid fluid extraction. The size, shape and location of the holes should be selected to be suitable for fluid extraction, as explained above. However, infusion can also be performed through the holes. Without limitation, suitable materials include plastics and elastomers such as silicone, polyurethane and polyethylene and the like.  
      Ports usable in connection with the catheter bodies described above are now described.  
      In the embodiment of  FIG. 1 , the proximal end  103  of the catheter body  100  terminates at and is connected for fluid communication to a subcutaneously implantable port  104 . The port has a membrane (referred to as a septum)  105  for percutaneous access to the port  104  by a suitably sized extraction needle, e.g., a 14-gauge needle. In one embodiment, the septum  105  is durable enough to permit at least 50 or more non-coring, self-healing passages by a 14 gauge or larger needle. In other embodiments, the septum  105  can withstand at least 100 or more, and preferably 200 or more passages.  
      The port  104  is constructed of any suitable materials, using any suitable methods. In one embodiment, the side walls and back wall of the port  104  may be formed of titanium, but other metals or plastics such as acetal homopolymers that are bioinert can be used, for example. The top surface is the septum  105 , which may be formed of silicone or other elastomer or plastic. In embodiments capable of withstanding  200  passages by a 14-gauge needle, the septum  105  of silicone has a surface area of about 1-6 cm 2  and be about 2-4 mm thick. Typically, but without limitation thereto, the septum  105  may have dimensions of about 1-2 cm by 1-3 cm.  
      The walls and septum  105  of the port  104  define a reservoir within that has a low, wide profile to minimize the volume of fluid held in the reservoir, and to maximize the comfort to the patient in whom the port  104  is implanted. The port may, without limitation thereto, have overall dimensions of 2 cm by 4 cm by 1 cm. Such a port  104  can be implanted in a large pocket formed on the patient&#39;s abdominal wall or in another location that avoids interference with patient mobility. The catheter body  100  and port  104  may include any suitable connector feature for connecting one to the other. For example, a conventional hub connection (not shown) can be used.  
       FIG. 4  shows an alternate embodiment of the invention directed to a multi-septum configuration. This multi-septum configuration is useable in combination with any of the catheter body configurations disclosed herein, and any other catheter body configurations. In the embodiment of  FIG. 4 , the port  401  at the proximal end  103  of the catheter  100  has two chambers  402 , each have a septum  403 , allowing two needles to be placed for more rapid drainage. The chambers  402  may be interconnected  404 , and may be connected to a single catheter  100  through a single hub  405 .  
      In the alternative embodiment shown in  FIG. 13 , the port  1301  has a ribbed outlet  1302  to which the catheter body  1303  is attached. A ribbed outlet  1302  such as shown can be used instead of a conventional hub, such as mentioned above. In this embodiment, the port outlet  1302  is disposed opposite the septum  1304 , an arrangement also thought to be advantageous in some cases.  
      Use of a ribbed outlet  1302  simplifies the construction and assembly of the catheter and port. The proximal end  1305  of the catheter body  1303  is simply slipped over the ribbed outlet  1302 , and is held in place by friction between the catheter body  1303  and the ribbed outlet  1302 .  
      Placing the ribbed outlet  1302  opposite the septum  1304  is advantageous at least in that the impedance of the structure to fluid flow is reduced relative to placing the outlet to the side of the port, as in the embodiments of  FIG. 1-7 . Moreover, implantation can be simplified using this arrangement because the entire assembly is inserted straight into the cavity to be drained, rather than at an angle or along a convoluted path. Yet another advantage of this arrangement is that the catheter is less likely to kink than in a configuration where the catheter body has to transition from a position parallel to the abdominal wall to one perpendicular to the abdominal wall.  
      In another alternative embodiment, shown in  FIGS. 22 and 23 , exhibiting advantages similar to those of the embodiment of  FIG. 13 , a right-angle outlet  2201  is employed. Port  2200  is substantially similar in construction and arrangement to port  104  of  FIG. 1 . However, outlet  2201  makes a right-angle bend towards the direction of implantation of a catheter body (not shown), so that kinks or bends are not introduced into the catheter body. Outlet  2201  may terminate in a conventional hub (not shown) or ribbed section (not shown) to grip the catheter body.  
      The port may also include other useful features. For example, the port may include suture loops  1306  by which the port can be secured to tissue in the patient&#39;s body. The port may have funnel shape to further reduce the impedance of the assembly to fluid flow during extraction.  
      As identified above, the port ( FIG. 1, 104 ) can be accessed through the system  105  by a conventional access needle, for example a 14-gauge needle. Alternatively, a removable core access needle  1400 , such as shown in  FIG. 14 , can be used. Such a needle may include a large bore, e.g., 14 gauge, hollow point  1401 . The point  1401  may be made of metal, perforated on the sides thereof  1402 , and have a beveled entry edge  1403  to prevent occlusion while in use. The point  1401  is affixed to a right-angle end  1404  of a suitable type of tubing  1405  that resists collapse under suction. In order to control access through such a needle, and to prevent coring of the septum ( FIG. 1, 105 ) during insertion, the removable core access needle  1400  has a removable stylete  1406  that resides within the hollow of the point  1401  when not accessing the port, and that is withdrawn when accessing the port. Stylete  1406  removal is facilitated by providing a diaphragm or septum  1407 , through which the stylete  1406  passes and may be inserted or withdrawn.  
      It has been found that no cuff, as is often conventionally provided, is necessary. However, if desired, a bacteriostatic cuff  106  may provided near the proximal end  103  of the catheter body  100 , so as to prevent inward migration of an infection. The cuff  106  promotes fibrous tissue ingrowth. Bacteriostatic cuffs of polyester impregnated with bacteriostatic compounds are suitable.  
      Leaking around the catheter can be prevented by use of a tissue collagen injection at one or more sites around the implanted system. Tissue collagen acts as a kind of biocompatible glue between the catheter body  100  and port  104 , and the surrounding tissues.  
      In yet another embodiment, a fully integrated, catheterless fluid extraction plug  1500  is shown in  FIG. 15 . This embodiment combines several features described above in connection with other embodiments, as now described.  
      The exemplary catheterless drainage plug  1500  has an expanded port section  1501  and an elongated body section  1502 . Any suitable port section shape can be used in combination with any suitable body section shape, including those shown in the other exemplary embodiments.  
      The catheterless plug embodiment is advantageous because of its simplicity. Without joints and rough edges that may be found in other designs, there are fewer locations to harbor potentially infectious matter or irritate the implantation site in the patient. The device is also less expensive and easier to manufacture than designs using multiple components and joints.  
      The devices described herein are all implanted using suitable techniques, including techniques known in the art. One such technique is now described.  
      First an incision is made in the patient&#39;s skin above the location where the device is to be implanted. The incision exposes a small area of the underlying cavity wall. A hollow needle is inserted through the cavity wall until a “fluid flash” is seen, that is an outflow of fluid from within the body cavity. The fluid flash indicates that the needle has been inserted into the desired location. Next, a guide wire is inserted through the needle to provide a defined path for the remainder of the devices employed. The needle is then withdrawn over the guide wire. A sheath and dilator are next inserted, over the guide wire. The dilator enlarges the hole through the cavity wall sufficiently to allow a catheter to be inserted. After the dilator has enlarged the hole, it is removed. The catheter is then slid over the wire and sheath and through the enlarged hole. Finally the sheath, and optionally the wire, is withdrawn, leaving the catheter in place.  
      Various modifications to the port could now be evident to the skilled artisan. For example, the bottom of the port could be curved to follow the curve of the patient&#39;s abdomen, for patient comfort. Alternatively, the port could be “almond-”shaped to leave room for two extraction needles. Preferably, the port shape accommodates a septum large enough to permit rotation of the skin/septum puncture site, so as to avoid skin breakdown as a result of repeated needle punctures. See, for example,  FIGS. 16-18 . The almond shape would allow room for deep needles, for example needles including side holes. Hollow needles with side holes would permit higher extraction flow rates than hollow needles having only an end hole. The eyelets  1306  may be filled with a membrane or not, as desired.  
      According to yet other variations, the shapes and features described above, and others, can be combined, as for example as shown in  FIGS. 19-21 .  FIG. 19  shows a helix  1901  combined with a pigtail  1902 .  FIGS. 20 and 21  show a helix  2001  combined with a straight section  2002 . In each case, the geometry is such that it allows straightening followed by self-coiling or bunching, for implantation.  
      The present invention has now been described in connection with a number of specific embodiments thereof. However, numerous modifications, which are contemplated as falling within the scope of the present invention, should now be apparent to those skilled in the art. Therefore, it is intended that the scope of the present invention be limited only by the scope of the claims appended hereto.