Abstract:
A method of implanting an injection port using the step of providing an injection port having a housing having a body, a fluid reservoir, a needle penetrable septum, and at least one stabilizing element mounted to the housing comprising a member having an undeployed position and a deployed position, wherein the stability element extends radially from the body. The method further involves the step of creating a surgical incision through the skin and subcutaneous fat layers of the patient to expose the fascia, and placing the injection port between the subcutaneous fat layer and the fascia tissue. The method even further involves the step of deploying the stability element.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates generally to the field of medicine, and more specifically to medical devices that are surgically implanted in a patient, and is particularly relevant to implantable injection or infusion ports such as used for chemotherapy and adjustable gastric band procedures.  
       BACKGROUND OF THE INVENTION  
       [0002]     Surgeons routinely implant subcutaneous injection ports in patients requiring periodic fluid injections such as for chemotherapy and gastric band adjustments. The injection port connects to a flexible tube catheter to transport the fluid to the affected area (subclavian vein, etc.) or the gastric band. Current injection ports comprise a rigid metal or plastic housing, which is about 25 mm in diameter and 15 mm tall. A thick, silicone septum captured within the rigid housing covers an inner chamber that fluidly communicates with the catheter. The surgeon uses a hypodermic needle to inject fluid into the chamber through the silicone septum.  
         [0003]     Such injection ports are commonly use in conjunction with adjustable gastric bands to treat morbid obesity. Examples of an adjustable gastric band can be found in U.S. Pat. No. 4,592,339 issued to Kuzmak; RE 36176 issued to Kuzmak; U.S. Pat. No. 5,226,429 issued to Kuzmak; U.S. Pat. No. 6,102,922 issued to Jacobson and U.S. Pat. No. 5,601,604 issued to Vincent, all of which are hereby incorporated herein by reference. In accordance with current practice, a gastric band is operatively placed to encircle the stomach. This divides the stomach into two parts with a stoma in-between. An upper portion, or a pouch, which is relatively small, and a lower portion which is relatively large. The small partitioned portion of the stomach effectively becomes the patient&#39;s new stomach, requiring very little food to make the patient feel full.  
         [0004]     Once positioned around the stomach, the ends of the gastric band are fastened to one another and the band is held securely in place by folding a portion of the gastric wall over the band and closing the folded tissue with sutures placed therethrough thereby preventing the band from slipping and the encircled stoma from expanding. Gastric bands typically include a flexible substantially non-extensible portion having an expandable, inflatable portion attached thereto. The inflatable portion is in fluid communication with such an injection site, or port. Injection or removal of an inflation fluid into or from the interior of the inflatable portion is used to adjust the size of the stoma either during or following implantation. By enlarging the stoma, the patient can eat more food without feeling as full, but will not lose weight as fast. By reducing the size of the stoma, the opposite happens. Physicians regularly adjust the size of stoma to adjust the rate of weight loss.  
         [0005]     Most commercially available injection ports have holes spaced around the perimeter of the housing for suturing the port to the tissue. Attaching the port to tissue helps to prevent the port from flipping over and/or migrating in the body. When implanting the injection port for a gastric band, the surgeon typically fastens the injection port with four sutures to the fascia covering the abdominal musculature and beneath the fat layer, which may be several centimeters thick for obese patients. Since for most commercially available ports the septum is accessible from only one side of the injection port, flipping over may require interventional surgery to right the port for subsequent injections.  
         [0006]     Currently many surgeons implant the gastric band and catheter using a laparoscopic procedure to minimize patient pain, cost, and recovery time. However, once the surgeon has implanted the gastric band and catheter, the surgeon may externalize the proximal end of the catheter through a peritoneal incision, fluidly connect the catheter to the injection port, and then use an open procedure to attach the injection port to the fascia over the abdominal musculature. Placement of the band around the stomach is a difficult and important part of the surgical procedure. Implantation of the injection port is no less critical to the overall success of the gastric band, but many surgeons regard this part of the procedure as routine and are anxious to complete it. In addition, suturing the injection port to tissue requires a large enough surgical incision for accessing the suturing site with dissecting instruments and needle graspers. The associated wound and tissue trauma may result in significant post-operative pain and recovery time for the patient. What is needed, therefore, is a subcutaneously implantable injection port that does not require suture attachment to tissue to prevent migration of the port and/or flipping over. It is important that such an injection port be positionable into soft tissue with minimal trauma to surrounding tissue. The port should allow quick healing of the surrounding wound and be comfortable and cosmetically acceptable to the patient.  
       SUMMARY OF THE INVENTION  
       [0007]     In accordance with the present invention, there is provided a method of implanting an injection port using the step of providing an injection port having a housing having a body, a fluid reservoir, a needle penetrable septum, and at least one stabilizing element mounted to the housing comprising a member having an undeployed position and a deployed position, wherein the stability element extends radially from the body. The method further involves the step of creating a surgical incision through the skin and subcutaneous fat layers of the patient to expose the fascia, and placing the injection port between the subcutaneous fat layer and the fascia tissue. The method even further involves the step of deploying the stability element. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0008]     We present the specific, novel features of this invention in the appended claims. The reader may best understand, however, the organization and methods of operation of this invention by referring to the detailed description and the following drawings:  
         [0009]      FIG. 1  is a side view of an injection port  2  of the prior art;  
         [0010]      FIG. 2  is a top view of injection port  2  of the prior art;  
         [0011]      FIG. 3  is a perspective view of injection port  2 , a connector  16 , a ferrule  18 , and a catheter  20 , in general alignment for assembly and implantation through a bodily incision  24 ;  
         [0012]      FIG. 4  is a perspective view of injection port  2  assembled to catheter  20  and attached to a tissue layer  26 ;  
         [0013]      FIG. 5  is a side view of a first embodiment of an injection port  100  with radially extendable, stabilizing elements  102 , shown in a deployed position;  
         [0014]      FIG. 6  is a top view of injection port  100  in the deployed position;  
         [0015]      FIG. 7  is a side view of injection port  100 , shown in an undeployed position;  
         [0016]      FIG. 8  is a top view of injection port  100 , shown in the undeployed position;  
         [0017]      FIG. 9  is a perspective, exploded view of the components of injection port  100 ;  
         [0018]      FIG. 10  is a side view of a second embodiment of an injection port  200 , shown in a deployed position;  
         [0019]      FIG. 11  is a top view of injection port  200  in the deployed position;  
         [0020]      FIG. 12  is a side view of injection port  200 , shown in an undeployed position;  
         [0021]      FIG. 13  is a top view of injection port  200  in the undeployed position;  
         [0022]      FIG. 14  is a perspective, exploded view of injection port  200 ;  
         [0023]      FIG. 15  is a side view of a third embodiment of an injection port  300 , shown in a deployed position;  
         [0024]      FIG. 16  is a top view of injection port  300  in the deployed position;  
         [0025]      FIG. 17  is a top view of injection port  300  in an undeployed position;  
         [0026]      FIG. 18  is a side view of injection port  300  in the undeployed position;  
         [0027]      FIG. 19  is a perspective, exploded view of injection port  300 ;  
         [0028]      FIG. 20  is a top view of a fourth embodiment of an injection port  400 ; shown in a deployed position;  
         [0029]      FIG. 21  is a side view of injection port  400  in the deployed position;  
         [0030]      FIG. 22  is a top view of a fifth embodiment of an injection port  500 ;  
         [0031]      FIG. 23  is a side view of injection port  500 ;  
         [0032]      FIG. 24  is a top view of a sixth embodiment of an injection port  600 ;  
         [0033]      FIG. 25  is a side view of injection port  600 ;  
         [0034]      FIG. 26  is a top view of a seventh embodiment of an injection port  700 ;  
         [0035]      FIG. 27  is a side view of injection port  700 ;  
         [0036]      FIG. 28  is a side view of an eighth embodiment of an injection port  800 ; and  
         [0037]      FIG. 29  is a top view of injection port  800 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0038]     Referring now to the drawings,  FIGS. 1 and 2  show an injection port  2  of the prior art. Injection port  2  generally may have a truncated, conical configuration, and comprises a housing  14 , a septum  4 , and a catheter support  8 . Injection port  2  further comprises a body  7  having a bottom surface, also called a distal closed end  13 , and an open proximal end  5 , which retains septum  4 . Housing  14  is typically made of a biocompatible, corrosion resistant metal. Septum  4  may be made of an elastomeric material such as silicone rubber, which is easily penetrable by a hypodermic needle. Housing  14  and septum  4  define a fluid reservoir  12  in injection port  2  for receiving and containing a fluid. Catheter support  8  extends through housing  14  to provide fluidic communication between fluid reservoir  20  and the exterior of injection port  2 . A flange  6  extends from housing  14  and contains a plurality of holes  10  for suturing injection port  2  to the tissue of a patient.  
         [0039]      FIG. 3  shows injection port  2  of the prior art as it may be assembled to a catheter  20  during a surgical procedure. When using injection port  2  in a laparoscopic procedure such as implantation of a gastric band, it may be necessary for the surgeon to assemble injection port  2  to catheter  20  during the laparoscopic procedure. This may be because injection port  2  may be too large to pass through a standard size (12 mm diameter) laparoscopic port, which may be used for access to the stomach inside the abdominal fluid reservoir. The surgeon may introduce the gastric band and catheter  20  into the abdominal fluid reservoir without injection port  2  attached to the free end of catheter  20 . Once the surgeon has secured the gastric band around the stomach, the surgeon externalizes the free end of catheter  20  through the abdominal muscle and fascia layers, subcutaneous fat layer, and the skin to assemble injection port  20  to the free end of catheter  20 . Then the surgeon implants the injection port subcutaneously at the desired location on the patient&#39;s abdomen. As shown in  FIG. 3 , a catheter element  16  fits over catheter  20  and locks catheter  20  tightly over catheter support  8  of injection port  2 . A catheter protector  18  also fits over catheter  20  and helps to prevent accidental puncture of catheter  20  when the surgeon accesses injection port  2  with a hypodermic needle during later injections of fluid. Once catheter  20  is fluidly connected to injection port  2 , the surgeon attaches injection port  2  with a plurality of sutures  22  to the fascia  26  covering the muscular layer of tissue. Typically the surgeon spends several minutes to suture injection port  2  to fascia  26 , working with limited access through an incision  24  in the patient.  FIG. 4  shows injection port  2  attached to fascia  26  with four sutures  22  prior to closure of incision  24 .  
         [0040]     The below embodiments describe an injection port that may be configurable into a collapsed or an undeployed position to facilitate placement into the tissue of the patient, and may be configurable, once positioned in the tissue of the patient, into an extended or a deployed position for long-term stability. The injection port resists “flipping” over, thereby allowing needle access to the septum for adding or withdrawing fluid, and provides sites for tissue in-growth for securing the injection port in the tissue of the patient. Furthermore, these embodiments eliminate the need to suture the injection port to tissue, thereby reducing surgery time and the tissue trauma associated with suturing.  
         [0041]      FIGS. 5, 6 ,  7 ,  8 , and  9  show a first embodiment of an injection port  100 , which includes a housing  104  having a body  107  made of a rigid material such as titanium, stainless steel, or a biocompatible polymer. Housing  104  may be of a similar design as housing  14  of the prior art shown in  FIG. 1 , but without flange  6 . A plurality of stability elements  102  attach to housing  104 . Each of stability elements  102  include a member  103  that may be made of coiled, metallic wire, preferably a non-corroding, stainless steel or titanium alloy spring wire such as used for the manufacture of coiled springs. Each of stability elements  102  have a torsion spring  105  that attaches member  103  to housing  104  such that stability elements  102  tend to spring from the undeployed position to the deployed position when not sufficiently restrained.  FIG. 5  is a side view and  FIG. 6  is a top view of injection port  100  while stability elements  102  are in a deployed position.  FIG. 7  is a side view and  FIG. 8  is a bottom view of injection port  100  while stability elements  102  are in an undeployed position. The surgeon may hold stability elements  102  in the undeployed position with a surgical grasper or gloved hand and then place injection port  100  into the incision of the patient. Once the surgeon has placed injection port  100  in the desired implant location of the patient, the surgeon may release injection port  100  so that stability elements  102  move to the deployed position. The surgeon may use conventional surgical tools to dissect tissue around injection port  100  and facilitate the full extension of stability elements  102 .  
         [0042]      FIG. 9  is an exploded, perspective view of injection port  100 . Each of stability elements  102  comprises member  103  and torsion spring  105  that springably attaches to housing  104  with a pin  108  pressed into a hole  110 . The space inside of member  103  allows the dissected tissue planes to heal together, thus helping to secure injection port  102  in the patient. Since each of stability elements  102  may be flexible and resiliently attached to housing  104 , the patient will not experience significant discomfort while bending/twisting that portion of his or her body. A septum  106  assembles into housing  104  in a similar manner as shown in  FIG. 1  of the prior art. (Each of the embodiments of injection port disclosed herein include a septum, a fluid reservoir, and a catheter support having a basic design and function similar to that of the prior art injection port described for  FIG. 1 .)  
         [0043]      FIGS. 10, 11 ,  12 ,  13 , and  14  show a second embodiment of an injection port  200 .  FIG. 10  is a side view, and  FIG. 11  is a top view of injection port  200  while in a deployed position.  FIG. 12  is a side view, and  FIG. 13  is a top view of injection port  200  while in an undeployed position.  FIG. 14  is an exploded, perspective view of injection port  200 , including a plurality of stability elements  202  made of a metallic wire. Each of stability elements  202  may have a pair of ends  208  that pivotally attach to a housing  204  in holes  210 . A septum  206  assembles into housing  204  in a similar manner as shown in  FIG. 1  of the prior art. In this embodiment, each of stability elements  202  may be D-shaped. Initially, the surgeon may hold housing  204  with a grasper or gloved hand while injection port  202  may be in the undeployed position. As the surgeon pushes injection port  200  into the tissue of the patient, stability elements  202  unfold into the deployed position while simultaneously penetrating into tissue. Therefore, the surgeon dissects the minimal amount of tissue to position injection port  200 , thus facilitating rapid healing and reducing the risk of infection. The subcutaneous fat layer and skin layers cover and hold injection port  200  while tissue heals around stability elements  202 .  
         [0044]      FIGS. 15, 16 ,  17 ,  18 , and  19  show a third embodiment of an injection port  300 .  FIG. 15  is a side view, and  FIG. 16  is a top view, of injection port  300  while in a deployed position.  FIG. 17  is a top view, and  FIG. 18  is a side view of injection port  300  while in an undeployed position.  FIG. 19  is an exploded, perspective view of injection port  300 , including a plurality of stability elements  302  that are made of a spring metal wire. Each of stability elements  302  may have a D-shape as in the previous embodiment, but may be also formed to have torsion springs  314  that attach to a housing  304  with-a pin  312  into holes  310  so that stability element  302  may be in the deployed position when unrestrained. The surgeon may place injection port  302  into the tissue of a patient in a similar manner as described for injection port  200  of  FIG. 14 . A septum  306  assembles into housing  304  as described for the prior art of  FIG. 1 .  
         [0045]      FIG. 20  is a top view and  FIG. 21  is a side view of a fourth embodiment of an injection port  400 , which includes a plurality of stability elements  402  attached to a housing  404 . Stability elements  402  are made of a flexible wire, such as super elastic, nickel-titanium memory metal, also known in the art as Nitinol. The surgeon may hold stability elements in the undeployed position while positioning injection port into the tissue of the patient, and then use a surgical tool or fingertips to gently position stability elements  402  in the deployed position.  FIG. 20  also shows a phantom view of a catheter  420  for fluid transfer to a remote portion of the body.  
         [0046]      FIG. 22  is a top view and  FIG. 23  is a side view of a fifth embodiment of an injection port  500 , that includes a stability element  502  attached to a housing  504 . Stability element  502  comprises a support member  508  that may be made of a flexible metal wire or plastic cord that may be attached to and forms the perimeter of a circular webbing  506 . Webbing  506  may be made of a biocompatible, polymeric mesh material such as Prolene (Trademark, Ethicon, Inc.) that attaches to housing  504  with a biocompatible adhesive. Webbing  506  provides a site for rapid tissue in-growth and healing, and to comfortably secure injection port  500  in the body.  
         [0047]      FIG. 24  is a top view and  FIG. 25  is a side view of a sixth embodiment of an injection port  600 , that includes a plurality of stability elements  602  attached to a housing  604  and normally extending radially. Each of stability elements  602  is made of a flexible metal wire material such as super elastic nickel titanium alloy, and includes a curled end  606 .  
         [0048]      FIG. 26  is a top view and  FIG. 27  is a side view of a seventh embodiment of an injection port  700 , that includes a stability element  702  attached to a housing  704 . Stability element  702  includes a flexible, star-shaped webbing  706  that may be injection molded from a plastic such as polyethylene with a plurality of support members  708  extending radially. An annular groove  705  of housing  704  retains stability element  702 .  
         [0049]      FIG. 28  is a side, sectional view and  FIG. 29  is a top view of an eighth embodiment of an injection port  800 , that includes a stability element  802 . In this embodiment, the surgeon or a medical assistant may assemble injection port  2  of the prior art ( FIG. 1 ) with stability element  802  during the surgical procedure (but prior to placement in the body.) Stability element  802  includes a webbing  806  integrally molded from a flexible, biocompatible plastic such as polyethylene, with a support member  808  that defines the perimeter of stability element  802 . A retaining lip  810 , also molded into stability element  802 , snaps over and retains flange  6  of housing  14 . Therefore it may be possible for a surgeon to use a conventional injection port that comes with a particular medical implant device, together with stability element  802 , to avoid the need to suture the injection port to tissue.  
         [0050]     A surgeon may implant an injection port in accordance with the present invention into the tissue of a surgical patient, without the need for suturing. The surgeon may create a surgical incision through the skin and subcutaneous fat layers of the patient. In the case of a gastric band implant, this incision may be typically made in the abdomen of the patient. The surgeon dissects tissue in the surgical incision to create space for a catheter and the injection port between the subcutaneous fat layer and the fascia tissue. The surgeon may use conventional surgical tools for dissection and/or fingertips. The surgeon connects the injection port to the catheter using components such as described for the prior art in  FIG. 1 . The surgeon holds the injection port in an undeployed position, and then positions the injection port and the catheter through the incision. The surgeon manipulates the injection port into final position upon the fascia tissue while allowing the injection port to change into a deployed position. Finally, the surgeon or medical assistant closes the skin and subcutaneous fat layers over the injection port and the catheter. The method may also include an additional step of suturing the stabilizing elements to the tissue.  
         [0051]     It will become readily apparent to those skilled in the art that the above invention has equally applicability to other types of implantable bands. For example, bands are used for the treatment of fecal incontinence. One such band is described in U.S. Pat. No. 6,461,292 which is hereby incorporated herein by reference. Bands can also be used to treat urinary incontinence. One such band is described in U.S. patent application Ser. No. 2003/0105385 which is hereby incorporated herein by reference. Bands can also be used to treat heartburn and/or acid reflux. One such band is described in U.S. Pat. No. 6,470,892 which is hereby incorporated herein by reference. Bands can also be used to treat impotence. One such band is described in U.S. patent application Ser. No. 2003/0114729 which is hereby incorporated herein by reference.  
         [0052]     While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. For example, as would be apparent to those skilled in the art, the disclosures herein have equal application in robotic-assisted surgery. In addition, it should be understood that every structure described above has a function and such structure can be referred to as a means for performing that function. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.