Patent Publication Number: US-2005131352-A1

Title: Subcutaneous injection port for applied fasteners

Description:
RELATED APPLICATIONS  
      This application claims the priority of provisional patent application Ser. No. 60/478,763, titled Fluid Injection Port For Adjustable Gastric Band, filed on Jun. 16, 2003, the disclosure of which is incorporated herein by reference. This application also incorporates by reference the following co-pending United States patent applications filed of even date herewith: application Ser. No. ______ (Subcutaneous Self Attaching Injection Port With Integral Fasteners, inventors: Conlon and Kolata); and application Ser. No. ______; (Subcutaneous Self Attaching Injection Port With Integral Moveable Retention Members, inventors: Conlon, Byrum, Hunt, Nuchols and Schulze). 
    
    
     TECHNICAL FIELD  
      The present invention relates in general to surgically implantable fluid injection ports, and is particularly directed to fasteners and methods for fastening subcutaneous peripherally attached ports. The invention will be specifically disclosed in connection with injection ports used with adjustable gastric bands, although the fasteners of the present invention may be used with many different subcutaneuosly attached devices, including injection ports used for vascular access such as the infusion of medications and blood draws.  
     BACKGROUND OF THE INVENTION  
      Injection ports are placed beneath the skin of a body for injecting fluids into the body, such as for infusing medication, blood draws, and many other applications, including adjustable gastric bands. Since the early 1980s, adjustable gastric bands have provided an effective alternative to gastric bypass and other irreversible surgical weight loss treatments for the morbidly obese. The gastric band is wrapped around an upper portion of the patient&#39;s stomach, forming a stoma that restricts food passing from an upper portion to a lower portion of the stomach. When the stoma is of the appropriate size, food held in the upper portion of the stomach provides a feeling of fullness that discourages overeating. However, initial maladjustment or a change in the stomach over time may lead to a stoma of an inappropriate size, warranting an adjustment of the gastric band. Otherwise, the patient may suffer vomiting attacks and discomfort when the stoma is too small to reasonably pass food. At the other extreme, the stoma may be too large and thus fail to slow food moving from the upper portion of the stomach, defeating the purpose altogether for the gastric band.  
      In addition to a latched position to set the outer diameter of the gastric band, adjustability of gastric bands is generally achieved with an inwardly directed inflatable balloon, similar to a blood pressure cuff, into which fluid, such as saline, is injected through a fluid injection port to achieve a desired diameter. Since adjustable gastric bands may remain in the patient for long periods of time, the fluid injection port is typically installed subcutaneously to avoid infection, for instance in front of the sternum. Adjusting the amount of fluid in the adjustable gastric band is achieved by inserting a Huber needle through the skin into a silicon septum of the injection port. Once the needle is removed, the septum seals against the hole by virtue of compressive load generated by the septum. A flexible conduit communicates between the injection port and the adjustable gastric band.  
      While a custom stapler for an injection port may have advantages over suturing, such as the time required to accomplish the attachment, it is believed that other approaches to attaching an injection port may have additional advantages or features not provided by traditional suturing or a stapler using bent wire staples.  
      Consequently, a significant need exists for a fluid injection port suitable for subcutaneous attachment that is quickly attachable yet is secure over a long period of time.  
     BRIEF SUMMARY OF THE INVENTION  
      As described herein, there is provided an injection port for injecting fluids into a body. The port includes a housing for placement beneath the skin of the body, and means for receiving a needle. Means integrally attached and fixed relative to the port are provided for receiving at least one fastener and aligning the fastener in its proper position for deployment in tissue adjacent said housing. According to another aspect of the present invention, the injection port includes a guidance configuration adapted to receive and guide a delivery end of a device for implanting fasteners in a position to retain the housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:  
       FIG. 1  is a diagrammatic drawing showing an injection port constructed in accordance with the present invention, connected to an adjustable gastric band wrapped around an upper part of a stomach.  
       FIG. 2  is a perspective view of the injection port shown in  FIG. 1 .  
       FIG. 2A  is a fragmentary, enlarged side view taken along line  2 A- 2 A of  FIG. 2 .  
       FIG. 3  is a perspective view of the injection port of  FIG. 1  during attachment to a fascia layer using an existing surgical instrument.  
       FIG. 4  is a fragmentary, enlarged side view of the injection port and surgical instrument as shown in  FIG. 3 .  
       FIG. 5  is a perspective view showing a fastener securing an injection port in place.  
       FIG. 6  is a side view of the fastener shown in  FIG. 5 .  
       FIG. 7  is a cross sectional drawing of the transfer tube of the surgical instrument with fasteners. 
    
    
      Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.  
     DETAILED DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION  
      Referring now to the drawings in detail, wherein like numerals indicate the same elements throughout the views,  FIG. 1 , adjustable gastric band  10  is shown wrapped around an upper portion of stomach  12 , kept in place by attaching the two ends together and extending portion  14  of the stomach  12  over adjustable gastric band  10  by suturing portion  14  to the stomach. One end of flexible conduit  16  is in fluid communication with the internal cavity of the balloon (not shown), with the other end being in fluid communication with an internal cavity (not shown) of injection port  18 . At the time adjustable gastric band  10  is implanted around a portion of the stomach, remote injection port  18  is also implanted at a suitable location, usually within the rectus sheaths, for transcutaneous access via a Huber needle.  
      Referring also to  FIGS. 2 and 2 A, injection port  18  includes frustroconical housing  20  having four circumferentially spaced recesses  22  formed therein. Nipple  24  is in fluid communication with the internal cavity defined by housing  20 , to which flexible conduit  16  is attached at some point in the procedure, typically after injection port  18  has been implanted. Fluid is added to or removed from the interior cavity of injection port  18  by inserting a Huber needle percutaneously into silicone septum  26  of the injection port  18 . Although septum  26  is made of silicon, the means of the injection port for receiving a needle includes any structure configured to self seal after puncture with a non-coring needle.  
      Although a specific configuration for injection port  18  is disclosed herein, there are many suitable configurations which may be used in conjunction with the present invention. For example, injection port  18  may include an annular flange about its base instead of recesses  22 , with the fastener openings and guidance configuration formed in the annular flange.  
      Each recess  22  includes side wall  22   a , and base  28  which has upper surface  28   a  which is generally parallel to distal end  20   a  of housing  20  (see  FIG. 4 ). Each base  28  includes a respective fastener opening  30  and includes a device guidance configuration which is adapted to receive and guide the delivery end of a device for implanting fasteners so to deliver fasteners into fastener opening  30  in the proper position and depth. In the depicted embodiment, the device guidance configuration is configured as device guidance bores  32  which is adapted to guide and receive a device having a cylindrical delivery end, and is shown as a counter-bore formed into surface  28   a , axially aligned with fastener opening  30 . In the embodiment depicted, guidance bore  32  includes frustroconical wall  32   a , which has a larger diameter at surface  28   a , leading to a smaller diameter at surface  30   b . The diameter of bore  32  at surface  28   a  is larger than the diameter end which assists to locate initially the delivery end in bore  32 , with wall  32   a  guiding the advancement of the delivery end into the proper position at surface  30   a . The diameter of bore  32  at surface  30   a  maintains the delivery end in the proper position relative to fastener opening  30  providing enough clearance so as not to bind and not to require excessive force to seat the delivery end in bore  32  against surface  30   a . Guidance bore  32  and wall  32   a  are not limited to frustroconical or inclined shapes. Wall  32   a  may, for example, be perpendicular to surface  30   a , adequately dimensioned to allow the delivery end into the proper position for implanting the fastener.  
      Since there are a variety of end configurations for delivery devices, the device guidance configuration may have a variety of configurations, as long as it has a shape which is complementary to and will cooperate with the particular end configuration. A single shape such as device guidance bore  32  as illustrated may cooperate with a variety of end configurations for delivery devices. The device guidance configuration may alternatively include raised portions extending above surface  28   a  to receive and guide the delivery end.  
      Referring to  FIG. 3 , there is shown surgical device  34  which is configured to implant fasteners. A suitable device is described in U.S. Pat. No. 6,447,524, which is incorporated herein by reference. Recesses  22  provide adequate clearance for device  34 , and for the fasteners delivered therefrom. Device  34  includes delivery end  36 , which as shown in  FIG. 3 , has been guided by bore  32  into the proper axially aligned position with fastener opening  30 . When device  34  is actuated, effector  38  extends from delivery end  36  for the placement and release of a fastener, extending through fastener opening  30  and into fascia layer  40 , creating the path for the fastener. The fastener is delivered into fascia layer  40  and engages upper surface  28   a  as effector  38  is withdrawn into device  34  and device  34  is withdrawn from bore  32 .  
      Referring to  FIG. 5 , fastener  42  is shown in its proper deployed position, aligned and positioned by side wall  22   a , base  28  and opening  30 , thereby securing injection port  18  in a deployed/implanted position. Referring also to  FIG. 6 , fastener  42  includes port hold down legs  44 , tissue retention legs or barbs  46 , and continuous body member  48  which connect port hold down legs  44  and retention legs  46  together. Port hold down legs  44  extend in opposite directions and engage upper surface  28   a.    
      Fastener  44  is constructed essentially the same as the fastener of U.S. Pat. No. 6,447,524, except that port hold down legs  44  are generally planar, allowing generally flat engagement with upper surface  28   a , such that retention legs  46  extend further to an appropriate depth into fascia layer  40 . The thickness of base  28  is selected so that retention legs  46  penetrate to a depth that will assure proper fixation of injection port  18 . Legs  44  being flat allows more of fastener  42  to extend below distal end bottom  20   a  than would a fastener of same length if the port hold down legs were arcuate as shown in U.S. Pat. No. 6,447,524. This allows the overall length of fastener  42  to be the same as the fastener shown in U.S. Pat. No. 6,447,524, thereby allowing fastener  42  to work in the surgical disclosed in U.S. Pat. No. 6,447,524, as shown in  FIG. 7 .  
      Practice of the present invention is not limited to the specific delivery device and fastener disclosed herein. Other fastener delivery devices and other fasteners, whether or not currently commercially available, may be used with an injection port constructed in accordance with the present invention, with the guidance configuration adapted to receive and guide the delivery end of such devices, and providing adequate clearance for the device and fastener.  
      For example, guidance configuration  32  may be adapted to receive and guide the delivery end of the stapler described in U.S. Pat. Nos. 5,634,584, 5,829,662, 5,588,581, 5,381,943, the disclosures of which are incorporated herein by reference. For use with such staplers, or any other fastener delivery devices, guidance configuration  32  is shaped complementary to a sufficient number of physical features of the delivery end of the stapler to receive and guide the delivery end adequately. Guidance configuration  32  may orient the staples tangentially, in which two openings in the base per staple are required, or may orient the staples outwardly, such as radially outward, using only a single opening in the base.  
      Thus, although the delivery device guidance configuration of the present invention has been described herein as being part of base  28  adjacent fastener opening  30 , such guidance may be formed in various configurations and locations suited to the particular delivery device utilized.  
      In summary, numerous benefits have been described which result from employing the concepts of the invention. The foregoing description of one or more embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The one or more embodiments were chosen and described in order to best illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.