Patent Publication Number: US-11638810-B2

Title: Radiopaque and septum-based indicators for a multi-lumen implantable port

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/139,852, filed Sep. 24, 2018, now U.S. Pat. No. 10,792,485, which is a division of U.S. patent application Ser. No. 15/442,371, filed Feb. 24, 2017, now U.S. Pat. No. 10,086,186, which is a division of U.S. patent application Ser. No. 12/267,160, filed Nov. 7, 2008, now U.S. Pat. No. 9,579,496, which claims the benefit of priority to U.S. Provisional Application No. 60/986,246, filed Nov. 7, 2007, U.S. Provisional Application No. 60/986,247, filed Nov. 7, 2007, and U.S. Provisional Application No. 61/110,507, filed Oct. 31, 2008, each of which is incorporated by reference in its entirety into this application. 
    
    
     BRIEF SUMMARY 
     Briefly summarized, embodiments of the present invention are directed to an implantable multi-lumen access port including indicators for ascertaining characteristics of the port. In one example embodiment, the access port comprises a housing that defines a first reservoir and a second reservoir. A first septum and second septum are respectively coupled with the housing to provide selective access to the first and second reservoirs. 
     Each septum includes a plurality of protrusions defined about a periphery thereof that are palpable after implantation of the port in a patient to determine a relative position of the first septum with respect to the second septum. 
     A radiographically observable indicator is also included on a base of the housing, so as to provide information relating to a characteristic of the dual-lumen port, such as suitability for power injection of fluids. The indicator in one embodiment includes a substantially rigid radiopaque component. In another embodiment, the indicator is defined as a recess in a port including a radiopaque material, such as titanium, for example. 
     These and other features of embodiments of the present invention will become more fully apparent from the following description and appended claims as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To further clarify embodiments of the disclosure, a more particular description will be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG.  1    is a perspective view of an example embodiment of an implantable port including a first septum and a second septum; 
         FIG.  2    is a schematic illustration of an embodiment of an implantable port including palpation features arranged in one example septum identification pattern; 
         FIG.  3    is a schematic illustration of an embodiment of an implantable port including palpation features arranged in another septum identification pattern; 
         FIG.  4    is a perspective view of another embodiment of an implantable port that includes a first septum and a second septum, and further includes a ridge between the first and second septa; 
         FIG.  5    is a top view of an implantable port that includes a first septum and a second septum, a ridge between the first and second septa, and a housing contour configured according to one embodiment; 
         FIG.  6    is a schematic illustration of an implantable port including palpation features arranged according to one embodiment; 
         FIG.  7    is a schematic illustration of an implantable port including palpation features arranged according to one embodiment; 
         FIG.  8    is a schematic illustration of an implantable port including palpation features arranged according to one embodiment; 
         FIG.  9    is a schematic illustration of an implantable port including palpation features arranged according to one embodiment; 
         FIG.  10    is a top view of an implantable port that includes a first septum and a second septum, a housing contour, and a plurality of protrusions disposed in proximate relation to the first and second septa, according to one embodiment; 
         FIG.  11    is a bottom view of the implantable port of  FIG.  1   , depicting features of a radiopaque indicator according to one example embodiment; 
         FIG.  12 A  is an exploded view of the implantable port of  FIG.  1   ; 
         FIG.  12 B  is an assembled bottom perspective view of the implantable port of  FIG.  1   ; 
         FIG.  13    is a bottom perspective view of an implantable port including a radiopaque indicator according to one embodiment; 
         FIG.  14    is a schematic illustration an image of the implantable port of  FIG.  13    that can be obtained by imaging techniques; 
         FIG.  15    is a schematic illustration, such as that of  FIG.  14   , of another embodiment of an implantable port; 
         FIG.  16    is a bottom view of another embodiment of an implantable port; 
         FIG.  17    is a bottom view of another embodiment of an implantable port; 
         FIG.  18    is a bottom view of another embodiment of an implantable port; 
         FIG.  19    is a top view of a radiographic indicator configured in accordance with one embodiment; 
         FIG.  20    is a top view of a radiographic indicator configured in accordance with one embodiment; 
         FIG.  21    is a top view of a radiographic indicator configured in accordance with one embodiment; 
         FIG.  22    is a top view of a radiographic indicator configured in accordance with yet another embodiment; 
         FIG.  23    is a bottom perspective view of an implantable port including an indicator according to one embodiment; and 
         FIGS.  24 A and  24 B  are cross sectional views of an edge of an indicator, such as the indicator shown in  FIG.  12 A . 
     
    
    
     DETAILED DESCRIPTION OF SELECTED EMBODIMENTS 
     Reference will now be made to figures wherein like structures will be provided with like reference designations. It is understood that the drawings are diagrammatic and schematic representations of exemplary embodiments of the invention, and are not limiting of the present invention nor are they necessarily drawn to scale. 
       FIGS.  1 - 22    depict various features of embodiments of the present invention, which are generally directed to ports, also referred to herein as access ports, for implantation into the body of a patient. In some situations, it can be desirable to facilitate access to the vasculature of a patient for purposes of blood withdrawal and/or infusions, such as when the patient is ill and may repeatedly undergo such procedures. In some instances, a catheter is situated within a blood vessel of the patient and a port is placed in fluid communication with the catheter. Accordingly, infusions and blood withdrawals may be made via the port, rather than directly through the wall of a blood vessel. In some situations, it can be advantageous to implant the port within the patient. 
     Reference is first made to  FIG.  1   , wherein an implantable port  10  is disclosed as configured in accordance with one example embodiment. As shown, the port  10  includes a housing  20  that defines a first reservoir  31  and a second reservoir  32 . A stem  35 , which extends from the housing  20 , is configured for coupling with a dual lumen catheter  36 . The stem  35  defines a first fluid passageway  41  configured to couple with a first lumen  37  of the catheter and a second fluid passageway  42  configured to couple with a second lumen  38  of the catheter. The first and second fluid passageways  41 ,  42  are in fluid communication with the first and second reservoir  31 ,  32 , respectively. 
     In the present embodiments, the port  10  includes a first septum  51  and a second septum  52 . The first septum  51  is coupled with the housing  20  and is configured to provide selective communication with the first reservoir  31 . For example, the first septum  51  includes an elastomeric material capable of being punctured by a needle, for example, a Huber needle, and substantially resealing upon removal of the needle. Similarly, the second septum  52  provides selective communication with the second reservoir  32 . 
     According to the present embodiment, the first septum  51  defines a plurality of palpation features, such as protrusions  71 A,  71 B,  71 C. Similarly, the second septum  52  defines a plurality of protrusions  72 A,  72 B,  72 C. In the illustrated embodiment, the protrusions  71 A,  71 B,  71 C define end points, or vertices, of a triangle, for example, an equilateral triangle, and are spaced at approximately regular intervals around the periphery of the first septum  51 . Similarly, the protrusions  72 A,  72 B,  72 C define end points, or vertices, of a triangle, for example, an equilateral triangle, and are spaced at approximately regular intervals around the periphery of the second septum  52 . The protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C extend outward from the septum surface such that the protrusions define a portion of top profile of the port  10  from the perspective of the port as shown in  FIG.  1   . 
     The port  10  is configured to be implanted subcutaneously within a patient. Accordingly, when the catheter  36  is coupled with the stem  35  and inserted in a blood vessel of the patient, fluid communication can be established with the blood vessel via one of the first and second reservoirs  31 ,  32 , such as by an infusion needle inserted through a corresponding one of the septa  51 ,  52 . 
     As seen in  FIG.  1   , each protrusion  71 A,  71 B,  71 C and  72 A,  72 B,  72 C is shaped to define a substantially hemispherical shape to provide a smooth surface and to avoid irritating body tissue proximate the port implanted location. In other embodiments, though, the shape, size, number, and placement of the palpation features can be modified from what is explicitly shown and described herein in order to suit a particular need. For instance, the protrusions can define a geometric or oval shape in one example. In one embodiment, the protrusions extend a distance of about 0.1 inch above the surface of the corresponding septum  51 ,  52 , though other size dimensions are of course possible. The protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C are integrally formed with the corresponding septum  51  or  52 , in one embodiment. 
     The palpation features, i.e., protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C, of the first and second septa  51 ,  52  can permit a clinician to properly identify the number of septa  51 ,  52  included in the port  10 , as well as the location and orientation of the desired septa, both generally and with respect to one another, in preparation for a given procedure (e.g., insertion of an infusion needle into a particular septum). For example, in many embodiments, when the port  10  is implanted subcutaneously in a patient, the clinician cannot visually distinguish the location of the first septum  51  from that of the second septum  52 , especially for ports made from radio-translucent materials, which are not sufficiently imaged radiographically. The clinician can instead feel or palpate the protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C through the skin to determine the general orientation of the port  10 , the location the septa  51 ,  52 , and/or to distinguish the location of one septum from that of the other. In one embodiment, the palpation protrusions further indicate suitability of the port for high fluid flow rate and/or high fluid pressure flow therethrough, such as power injection. These and other characteristics of the port can be indicated by the e protrusions described herein. 
     In many instances, a clinician has a need to properly identify the desired septum  51 ,  52 . For example, in some instances, it can be undesirable for the clinician to mistakenly puncture the same septum twice when the clinician&#39;s intent is to use each septum separately. It can also be undesirable for the clinician to mistakenly fail to puncture either septum and miss the port entirely. Accordingly, the protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C are arranged in present embodiments in an identification pattern to reduce the likelihood of clinician confusion and/or error when identifying the location and/or orientation of the septa  51 ,  52 . 
       FIG.  2    is a schematic illustration of an embodiment of the port  10  having protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C arranged in a first septum identification pattern  100 . In the illustrated embodiment, the identification pattern  100  includes a plurality of sub-patterns  105 A,  105 B,  105 C. Each sub-pattern  105 A,  105 B,  105 C substantially defines a triangular shape. Each set of protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C separately defines one of the sub-patterns  105 A,  105 B, respectively, and the protrusions  71 A of the first septum  51  and the protrusions  72 B,  72 C of the second septum  52  cooperate to define a third sub-pattern  105 C. 
       FIG.  3    is a schematic illustration of an embodiment of the port  10  having protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C arranged in a second septum identification pattern  110 . In detail, the protrusions  71 A,  71 B,  71 C define an equilateral triangle sub-pattern  115 A bisected by a long axis  90  of the port  10  (see also  FIG.  1   ). Similarly, the protrusions  72 A,  72 B,  72 C define an equilateral triangle sub-pattern  115 B oppositely positioned with respect to the triangle defined by the protrusions  71 A,  71 B,  71 C and which is also bisected by the port long axis  90 . 
     A perimeter or outline of the pattern  110  defines a pattern that can readily assist a clinician to determine a characteristic of the septa  51 ,  52  with respect to the one another. In particular, the pattern can assist a clinician in distinguishing the relative locations of the septa  51 ,  52 . For example, the opposing edges, defined by the protrusions  71 A,  71 B and  72 B,  72 C, respectively, of the pattern  110  can help a clinician to determine that more of the surface areas of the septa are between the opposing edges of the pattern than outside of the opposing edges. In addition, the pattern  110  does not include any sub-patterns that are confusingly similar to the triangular sub-patterns  115 A,  115 B. In another implementation, the pattern  110  can assist a clinician in determining a general orientation of the port  10  as implanted within the patient. 
       FIG.  4    depicts another embodiment wherein palpation features are included on an implantable port. In particular, a port  210  includes a housing  20  that defines a ridge  220  between the septa  51 ,  52 . As before, the first septum  51  defines a plurality of palpation features including protrusions  71 A,  71 B,  71 C, while the second septum  52  defines a plurality of palpation features including protrusions  72 A,  72 B,  72 C. The protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C are arranged as opposing equilateral triangles in mirror-image to one another, similar to the pattern  110  shown in  FIG.  3   . The ridge  220  can further aid in distinguishing the locations of the septa  51 ,  52 . 
       FIG.  5    depicts another embodiment wherein palpation features are included on an implantable port. In particular, a port  310  includes a housing  20  that defines a ridge  325  between the septa  51 ,  52 . As before, the first septum  51  defines a plurality of palpation features including protrusions  71 , while the second septum  52  defines a plurality of palpation features including protrusions  72 . The protrusions  71  and  72  are arranged as opposing equilateral triangles, similar to the pattern  110  shown in  FIG.  3   . The ridge  325  can further aid in distinguishing the locations of the septa  51 ,  52 . Note that the housing defines a relatively more contoured outline than in the embodiments shown in  FIGS.  1  and  4   . 
       FIGS.  6 - 9    depict further examples of palpation feature configurations for the implantable port, according to example embodiments.  FIG.  6    shows two oppositely positioned protrusions  171 A,  171 B included on the periphery of the septum  51 , and two similarly positioned protrusions  172 A,  172 B included on the periphery of the septum  52 . The protrusions  171 A,  171 B and  172 A,  172 B are positioned at about 0 and 180 degree “compass” positions on their respective septa  51 ,  52 , though it is appreciated that the respective positions of the protrusions can be modified from what is shown here. 
       FIG.  7    shows four equally spaced protrusions  271 A,  271 B,  271 C,  271 D included on the periphery of the septum  51 , and four equally spaced protrusions  272 A,  272 B,  272 C,  272 D included on the periphery of the septum  52 . The protrusions  271 A,  271 B,  271 C,  271 D and  272 A,  272 B,  272 C,  272 D are positioned at about 0, 90, 180, and 270 degree compass positions on their respective septa  51 ,  52 , though it is appreciated that the respective positions of the protrusions can be modified from what is shown here. 
       FIG.  8    shows four equally spaced protrusions  371 A,  371 B,  371 C,  371 D included on the periphery of the septum  51 , and two equally spaced protrusions  372 A,  372 B included on the periphery of the septum  52 . The protrusions  371 A,  371 B,  371 C,  371 D are positioned at about 0, 90, 180, and 270 degree compass positions on the septum  51 , while the protrusions  372 A,  372 B are positioned at about 90 and 180 degree compass positions on the septum  52 , though it is appreciated that the respective positions of the protrusions can be modified from what is shown here. 
       FIG.  9    shows three equally spaced protrusions  471 A,  471 B,  471 C included on the periphery of the septum  51 , and three equally spaced protrusions  472 A,  472 B,  472 C included on the periphery of the septum  52 . The protrusions  471 A,  471 B,  471 C and  472 A,  472 B,  472 C are positioned to define vertices of imaginary equilateral triangles on their respective septa  51 ,  52  such that the bases of each triangle face one another to define a septum identification pattern  480 . 
       FIG.  10    depicts yet another embodiment wherein palpation features are included on an implantable port. In particular, a port  510  includes a housing  20  defining two apertures into which the septa  51 ,  52  are inserted, as before. A plurality of protrusions  571  are included on and defined by the port housing  20  proximately adjacent the periphery of the septa  51 ,  52 . The protrusions  71  and  72  define vertices of opposing equilateral triangles, similar to the pattern  110  shown in  FIG.  3   . Thus it is noted that the palpation features can be included on either areas of the port in addition to the septa. Note further that the housing defines a relatively more contoured outline than in the embodiments shown in  FIGS.  1  and  4   , thus illustrating that the shape of the housing  20  can vary from what is described herein. 
     As the embodiments above make clear, the number, size, position, and shape of the palpation features can be modified while residing within the scope of embodiments of the present invention. In addition to the above embodiments, it is appreciated, for example, that the protrusions can define sub-patterns other than equilateral triangles, including acute triangles, obtuse triangles, etc. Additionally, one or more, two or more, three or more, four or more, five or more, etc. protrusions could be used, and need not be arranged about the periphery of the septa. In various embodiments, the port comprises two or more septa with protrusions extending therefrom. The protrusions can define a variety of different shapes, and may be sized differently. Thus, the foregoing examples are merely illustrative in nature. 
     Reference is now generally made to  FIGS.  11 - 22    in describing various details regarding further embodiments of the present invention. As has been described, in many implementations, it can be desirable to determine information regarding an access port subsequent to implantation in the body of a patient. For example, in some embodiments, it can be desirable to determine whether the port has flipped within the body such that the septa thereof undesirably face away from the skin at the implantation site. 
     Additionally, it can be desirable to determine the number of septa included in an implanted port, and/or the relative orientation of the septa. For example, it is generally desirable to determine whether a port provides fluid access to multiple lumens of a catheter operably connected thereto, and if so, to determine the relative orientations of septa associated with the lumens. 
     In further instances, it can be desirable to determine a functional characteristic of the implanted port. For example, some embodiments of the port are configured to withstand relatively high pressure and flow rates typically associated with power injection of fluids through the port during relatively demanding procedures (e.g., computed tomography, or “CT,” scans), in which contrast media is rapidly infused through the port and connected catheter and into a vascular system. “Power injection” is defined herein to include fluid infusion under relatively high flow rates and/or relatively high pressures. For instance, in one embodiment power injection includes fluid infusion by a power injection machine producing fluid pressures of up to about 325 psi, resulting in fluid pressures in the port  10  between about 50 and about 90 psi and fluid flow through the port at a rate between about two and about five milliliters per second. 
     During power injection, a needle can be inserted in a septum of the port and connected to a power injection machine, which can introduce contrast media through the port at a relatively high flow rate detailed above. Certain ports may not be able to withstand pressures corresponding to high flow rates during power injection. Accordingly, it is often necessary to determine whether an implanted port is compatible for power injection. 
     With reference to  FIG.  11   , in one embodiment, the port  10  includes an indicator  1100  that includes radiopaque material. The indicator  1100  can define a variety of shapes, figures, symbols, or other indicia to convey information regarding a characteristic of the port  10 . In some embodiments, the indicator  1100  is mounted, painted, screened on, or otherwise affixed to a bottom surface  20 A primarily defined by a base  25  of the port housing  20 , as shown in the  FIG.  11   . As depicted in  FIG.  11   , the bottom surface  20 A of the port housing  20  is defined primarily by the base  25 , and partially defined by a cap  27  that is mated with the base during port manufacture to define the complete housing.  FIG.  11    further shows that the indicator  1100  is centered with respect to a raised portion  25 A of the base  25 , though in other embodiments, placement of the indicator can vary from this configuration. Indeed, in other embodiments the indicator can be provided on another surface of the housing. In still other embodiments, at least a portion of the indicator can be incorporated within the housing. 
     In the illustrated embodiment, the indicator  1100  is an insertable piece produced from a radiopaque substance, such as any one or more of suitable metals/metal alloys. In one embodiment, the indicator  1100  is formed from a metallic material including titanium, such as titanium  64 , though many other metals and other radiopaque materials could also be employed, including stainless steel, ceramic, ceramic slurry including ceramic powder intermixed with an epoxy or resin, paintable or injectable substances (including tungsten-filled solution), and silk-screened products, for instance. In one embodiment, the substance from which the indicator piece is formed is biocompatible so as to prevent associated complications after implantation into the patient, is self-oxidizing, and is non-ferromagnetic so as to prevent imaging problems when MRI procedures are employed. In one implementation, for instance, the indicator piece  1100  including titanium is between approximately 0.010 and about 0.020 inch thick, about 0.8 inch long, and about 0.4 inch wide. Of course, other dimensions are possible. In one embodiment, the insertable piece that defines the indicator  1100  is rigid before attachment to the port housing  20 . In another embodiment, the indicator can be initially pliable, then solidify to rigidity either before or after attachment to the port housing. 
     In the illustrated embodiment, the indicator  1100  includes a first portion  1111  and a second portion  1112 . The indicator first and second portions  1111 ,  1112  indicate in the present embodiment that the port  10  is a dual lumen port configured for use with a dual lumen catheter. Because the indicator  1100  is radiopaque, the two portions  1111 ,  1112  will be visible through imaging techniques, such as radiographic (x-ray) imaging. Thus, a clinician viewing a radiographic image taken of the region of the patient in which the port  10  is implanted can see the x-ray shadow of the indicator  1100  on the image and understand that the port, by its inclusion of the two portions  1111  and  1112 , includes two septa  51 ,  52 . 
     In greater detail, the indicator portions  1111  and  1112  define equilateral triangles positioned side-by-side. Indicia  1114  are included on the indicator first and second portions  1111 ,  1112  to convey additional information regarding the port  10 . In the illustrated embodiment, the indicia  1114  include alphanumeric characters, such as “C” and “T,” defined within the triangular portions, which indicate that the port  10  is suitable for use with power injection. The indicia  1114  included in the indicator are reversed, or backwards, when reviewed from below as in  FIG.  11    such that the indicia will appear non-reversed when radiographically imaged from a vantage point above the port  10 . Both the first and second portions  1111 ,  1112  of the indicator  1100  include a plurality of holes  1116  defined therein so as to reduce heat sinking when the indicator is heat bonded to the port base  25 , as explained further below. 
     The exploded view of the port  10  in  FIG.  12 A  shows that the indicator  1100  is sized to fit within a cavity  1120  defined on the port bottom surface  20 A, more specifically the raised portion  25 A of the port base  25 . In one embodiment, the port base and cap  25 ,  27  are composed of an engineering plastic polymer material including Polyoxymethylene (“POM”), also known as an acetyl resin, and the cavity  1120  is defined as part of the molding process that defines the port base  25 . In another embodiment, the cavity  1120  is defined by machining or other suitable process after the port base  25  has been produced. The indicator  1100  in one embodiment is attached to the port base in the cavity  1120  by heat bonding during the same ultrasonic welding process that joins the port base  25  to the port cap  27 . The holes  1116  ( FIG.  11   ) are included in the indicator  1114  to prevent excessive heat sinking during the ultrasonic welding process, thus ensuring an adequate attachment of the indicator to the port base  25 . 
     In another embodiment, the indicator can be press-fit into the cavity  1120 . In yet another embodiment, a combination of press-fitting and ultrasonic welding can be employed to attach the indicator  1100 . Of course, other suitable attachment methods can also be pursued, including insert molding the indicator into the port base, and other materials may be used to form the port base and cap.  FIG.  12 B  shows the port  10  and indicator  1100  after attachment of the indicator on the bottom surface  20 A is complete. 
     The indicator described herein can indicate various characteristics of the multi-lumen port, including suitability of the port for power injectability (described above), the number or reservoirs included in the port, and the orientation and position of the septa of the port. 
       FIG.  13    shows the indicator  1100  of the port  10  according to another embodiment, wherein each of the indicator first and second portions  1111 ,  1112  includes a substantially circular outline  1165 ,  1166 . The first and second portions  1111 ,  1112  further include rounded inward extensions  1171 A,  1171 B,  1171 C,  1172 A,  1172 B,  1172 C, which are intended to convey that protrusions, such as the protrusions  71 A,  71 B,  71 C and  72 A,  72 B,  72 C are provided on the septa  51 ,  52 , as seen in  FIG.  1   . In one embodiment, the circular outlines  1165 ,  1166  and the inward extensions  1171 A,  1171 B,  1171 C,  1172 A,  1172 B,  1172 C correspond to a normal projection of the outer perimeter of the septa  51 ,  52  onto the port bottom surface  20 A. The first and second portions  1111 ,  1112  further include indicia, such as the flipped or reversed letters “C” and “T,” as shown. 
       FIG.  14    illustrates an image  2160  of the port  10  that can be obtained by imaging techniques, such as radiographic imaging, ultrasound imaging, or other suitable techniques. As shown, the image  2160  includes information conveyed by the various indicator components described above, which can be readily perceived by a clinician observing the image. For example, the indicia letters “C” and “T” indicate to the clinician that the port  10  is power-injection compatible. Further, the non-reversed orientation of the imaged letters indicates that the port  10  is properly positioned, i.e., not flipped within the patient. The images of circular outlines  1165 ,  1166  and of the inward extensions  1171 A,  1171 B,  1171 C,  1172 A,  1172 B,  1172 C can indicate that the port  10  includes two septa  51 ,  52 , and further helps in determining the orientation of the septa. 
       FIG.  15    illustrates an image  2260  that can be obtained from another embodiment of the port  10 , wherein an indicator  2200  is shown, including first portion  2211 , second portion  2212 , and indicia  2214 A indicating the entity producing the port, and  2214 B indicating by the letters “CT” that the port is power injectable. 
       FIG.  16    depicts another embodiment of an indicator  2300 , including a first portion  2311  and a second portion  2312 . In contrast to previous embodiments, the first and second portions  2311 ,  2312  are separate from one another. 
       FIG.  17    depicts another embodiment of an indicator  2400 , including a first portion  2411  and a second portion  2412 . The indicator  2400  is sized in the present embodiment such that the first and second portions  2411 ,  2412  define a plurality of end points  2418 , such as triangular vertices, which extend past the bottom periphery of the base  25  and are received into corresponding recesses  2420  defined in the portion of the bottom surface  20 A defined by the cap  27 . Such a configuration enables the indicator  2400 , as a rigid piece, to be placed by itself within the mold used to form the port base  25  before molding occurs, thus allowing the port base to be molded about the indicator. Note that, though it is shown as exposed on the port bottom surface in the present embodiments, the indicator can be integrated into the port such that it is not seen upon visual inspection. 
       FIG.  18    depicts another embodiment of an indicator  2500  on the port bottom surface  20 A. As shown, the indicator includes a lightning bolt, which can indicate, among other things, that the port  10  includes two septa, each of which is compatible for power injection. As the port  10  is often included in a kit, the kit can include instructions for use relative to the port as well as a guide for interpreting the indicator(s) of the port. 
       FIG.  19    depicts an example of an indicator  2600  for use with a port according to one embodiment, including a triangular first portion  2611  and an overlapping triangular second portion  2612 . Alphanumeric indicia  2614 A are included with each portion  2611 ,  2612  to indicate power injection compatibility, as are inward extension indicia  2614 B corresponding to protrusions included on the septa of the port. 
       FIG.  20    depicts another example of an indicator  2700  for use with a port according to one embodiment, including a triangular first portion  2711  and an overlapping triangular second portion  2712 . Alphanumeric indicia  2714 A are included with each portion  2711 ,  2712  to indicate power injection compatibility, as are inward extension indicia  2714 B corresponding to protrusions included on the septa of the port. 
       FIG.  21    depicts another example of an indicator  2800  for use with a port according to one embodiment, including a triangular first portion  2811  and an overlapping triangular second portion  2812 . Alphanumeric indicia  2814 A are included with each portion  2811 ,  2812  to indicate power injection compatibility, as are inward extension indicia  2814 B corresponding to protrusions included on the septa of the port. 
       FIG.  22    depicts another example of an indicator  2900  for use with a port according to one embodiment, including a triangular first portion  2911  and an overlapping triangular second portion  2912 . Alphanumeric indicia  2914 A are included with the indicator  2900  to indicate power injection compatibility. Inward extension indicia  2914 B are included with the first and second portions  2911 ,  2912  corresponding to protrusions included on the septa of the port. A plurality of end point extensions  2918  extend from the end points of the indicator portions  2911 ,  2912 , to enable the indicator  2900 , as a rigid piece, to be placed by itself within the mold used to form the port base before molding occurs, thus allowing the port base to be molded about the indicator. 
       FIG.  23    depicts yet another embodiment of an indicator for the port  10 , wherein an indicator is formed as recess  2920  on the bottom surface  20 A of the port housing  20 . The recess  2920  in  FIG.  23    includes a groove defining a double triangle shape, and a recessed “C” and “T” serving as alphanumeric indicia, though in other embodiments one of a variety of other configurations can be defined in the port. The port housing  20  in this embodiment includes a radiopaque material, such as titanium. Other metallic substances, alloys, or materials can also be employed. The recess  2920  is defined on the port housing bottom surface  20 A by any suitable process, including etching, machining, molding, etc. The depth of the recess  2920  depends on the overall size and thickness of the housing  20 . In one embodiment, the recess  2920  can be filled with a filler material, such as silicone, to provide a smooth port bottom surface  20 A. Note that the recess can be defined in reverse relief to what is shown in  FIG.  23   , in one embodiment. Note also that in one embodiment, the recess  2920  can be filled with a material that is more or less radiopaque than the material that forms the port housing  20  to provide a contrasting radiographic image. In one embodiment, the filler material can include a ceramic slurry, as already mentioned. 
     Because of its formation from a sufficiently thick radiopaque material, the port housing  20  itself is generally radiopaque except for relatively thinned areas of the housing. Definition of the recess  2920  therefore provides a relative difference in the thickness of the port  10  when viewed from above in a radiographic image. In other words, the portions of the recess  2920  provide a relatively thinner obstacle for x-rays to pass through than relatively thicker areas of the port, resulting in less radiopacity for the recess. Thus, the image formed by the recess  2920  will appear relatively lighter on a radiographic image of the port  10 , enabling a clinician to perceive the shape, symbols, indicia, or other elements of the indicator defined by the recess and readily determine an aspect of the port, its reservoirs, and/or its septa. It is therefore appreciated that an indicator as described and contemplated herein, can serve to provide either a greater or lesser radiopacity relative to other portions of the implantable port. 
       FIGS.  24 A and  24 B  show examples of cross sectional views of an edge of an indicator, such as the indicator  1100  shown in  FIG.  12 A , for example. According to example embodiments, the indicator  1100  can be die stamped or chemically etched, e.g., one or two-sided etching, from a metal sheet. In either case, depressions or protrusions, such as the protrusions  1100 A shown in  FIGS.  24 A and  24 B , can be formed as a result. When the indicator  1100  is later attached to the bottom surface of a port via ultrasonic bonding or heat staking, the protrusions  1100 A can interact with the reflowed material immediately adjacent thereto, thus anchoring the indicator to the port housing when the reflowed material has solidified. 
     Embodiments of the present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative, not restrictive. The scope of the present disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.