Abstract:
A method for implanting surgical injection port. The injection port is of the type having a housing with a closed distal end, an open proximal end and a fluid reservoir therebetween. The housing further includes a needle penetrable septum attached to the housing about the opening, and at least one attachment mechanism mounted to the housing for initially attaching the port to tissue. The attachment mechanism is made from a bioabsorbable material. The method further includes the steps of making an incision in the skin of a patient to expose fascia, attaching the port to the fascia by deploying the attachment mechanism, closing the incision, and removing the attachment mechanism through bioapsorbtion.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention has application in conventional endoscopic and open surgical instrumentation as well as application in robotic-assisted surgery. The present invention has even further relation to adjustable surgically implantable bands, such as gastric bands for the treatment of obesity.  
       BACKGROUND OF THE INVENTION  
       [0002]     The percentage of the world&#39;s population suffering from morbid obesity is steadily increasing. Severely obese persons are susceptible to increased risk of heart disease, stroke, diabetes, pulmonary disease, and accidents. Because of the effect of morbid obesity to the life of the patient, methods of treating morbid obesity are being researched.  
         [0003]     Numerous non-operative therapies for morbid obesity have been tried with virtually no permanent success. Dietary counseling, behavior modification, wiring a patient&#39;s jaws shut, and pharmacological methods have all been tried, and failed to correct the condition. Mechanical apparatuses for insertion into the body through non-surgical means, such as the use of gastric balloons to fill the stomach have also been employed in the treatment of the condition. Such devices cannot be employed over a long term, however, as they often cause severe irritation, necessitating their periodic removal and hence interruption of treatment. Thus, the medical community has evolved surgical approaches for treatment of morbid obesity.  
         [0004]     Most surgical procedures for treatment of morbid obesity may generally be classified as either being directed toward the prevention of absorption of food (malabsorption), or restriction of stomach to make the patient feel full (gastric restriction) The most common malabsorption and gastric restriction technique is the gastric bypass. In variations of this technique, the stomach is horizontally divided into two isolated pouches, with the upper pouch having a small food capacity. The upper pouch is connected to the small intestine, or jejunum, through a small stoma, which restricts the processing of food by the greatly reduced useable stomach. Since food bypass much of the intestines, the amount of absorption of food is greatly reduced.  
         [0005]     There are many disadvantages to the above procedure. Typically the above mentioned procedure is performed in an open surgical environment. Current minimally invasive techniques are difficult for surgeons to master, and have many additional drawbacks. Also, there is a high level of patient uneasiness with the idea of such a drastic procedure which is not easily reversible. In addition, all malabsorption techniques carry ongoing risks and side effects to the patient, including malnutrition and dumping syndrome.  
         [0006]     Consequently, many patients and physicians prefer to undergo a gastric restriction procedure for the treatment of morbid obesity. One of the most common procedures involves the implantation of an adjustable gastric band. 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 patients new stomach, requiring very little food to make the patient feel full.  
         [0007]     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 a remote 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.  
         [0008]     For most fluid injection ports for the above described bands are attached underneath the skin to the fascia of a patient. Such ports are often provided with suture holes and the port is sutured to the tissue. However, alternative means of attaching the port to the patient, such as using integral hooks, can be used as well. Such other means for attaching the port to a patient are described in commonly assigned and co-pending U.S. patent application Ser. No. 10/741,785 filed Dec. 19, 2003; Ser. No. 60/478,763 filed Dec. 19, 2003; Ser. No. 10/741,868 filed Dec. 30, 2003; all of which are hereby incorporated herein by reference.  
         [0009]     However, many of the prior art fasteners could cause patient discomfort, including pain. It is well known that once the port is placed a fibrotic capsule begins to grow over the port until it is completely encapsulated. The rate at which the fibrotic capsule grows varies from patient to patient, but generally surgeons agree that the port is fully encapsulated after 2 months. Once the port has been captured by the fibrotic capsule, there is no longer a need for the port to be fastened with sutures or other types of fasteners. In fact, it would be desirable if these additional fastening means were no longer part of the port system so as to not cause patient discomfort.  
       SUMMARY OF THE INVENTION  
       [0010]     In accordance with the present invention, there is provided a method for implanting surgical injection port. The injection port is of the type having a housing with a closed distal end, an open proximal end and a fluid reservoir therebetween. The housing further includes a needle penetrable septum attached to the housing about the opening, and at least one attachment mechanism mounted to the housing for initially attaching the port to tissue. The attachment mechanism is made from a bioabsorbable material. The method further includes the steps of making an incision in the skin of a patient to expose fascia, attaching the port to the fascia by deploying the attachment mechanism, closing the incision, and removing the attachment mechanism through bioapsorbtion. 
     
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       [0011]     The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:  
         [0012]      FIG. 1  is a perspective view of a surgically implantable fluid port made in accordance with the present invention, showing the port attached to an adjustable gastric band.  
         [0013]      FIG. 2  is a perspective view of a surgically implantable fluid port made in accordance with the present invention.  
         [0014]      FIG. 3  is a cross section of the port shown in  FIGS. 1 and 2 , taken along line  3 - 3  in  FIG. 1 .  
         [0015]      FIG. 4  is a view similar to that of  FIG. 3  but showing the fluid port implanted within a patient. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     Referring now to the drawings wherein like numerals indicate the same elements throughout the views, as stated above there is shown in  FIG. 1  an adjustable gastric band  1  of the type described in the above mentioned incorporated references. Band  1  is implanted within a body of a patient to surround the stomach  12 . The inflatable portion of the band is in fluid communication with injection port  10  via a catheter tube  52 . Tube  52  has a proximal end  53  attached to the port  10  and a distal end  55  attached to adjustable gastric band  1 . Port  10  can be used for a wide range of devices in the medical field and not only for gastric bands. For example the port can also used for vascular access for drug delivery.  
         [0017]     As seen from  FIGS. 2 and 3 , surgically implantable injection port  10  includes a housing  12 . Housing  12  can be made from any number of materials including stainless steel, titanium, or polymeric materials. Housing  12  has a distal back portion or closed distal end  14  and a perimeter wall portion  16  extending proximally from the back portion  14  at an angle. Wall portion  16  defines a proximal opening or open proximal end  18 , and a fluid reservoir  20  between opening  18  and back portion  14 . The port includes a needle penetrable septum  22  attached to the housing about the opening  18  so as to cover the opening and seal the reservoir  20 . Septum  22  can be made from any number of materials including silicone. Septum  22  is preferably placed in a proximal enough position such that the depth of the reservoir  20  is sufficient enough to expose the open tip of a needle, such as a Huber needle, so that fluid transfer can take place. Septum  22  is preferably arranged so that it will self seal after being punctured by a needle and the needle is withdrawn. In one embodiment, the septum is made from silicone which is under compression when attached to the housing. Port  10  further includes a catheter tube connection member  30 , in fluid communication with reservoir  20 .  
         [0018]     Port  10  is implanted into a patient and attached to the fascia just below the skin of the patient, so that fluid can be inserted and withdrawn from the inflatable portion with a syringe. As seen from the figures, port  1  includes one or more attachment mechanisms  70 , taking the form of an arcuate hook. However, for purposes of this invention, the attachment mechanism could take the form of alternative means such as using suture. Some of these other means for attaching the port to a patient are described in commonly assigned and co-pending U.S. patent application Ser. No. 10/741,785 filed Dec. 19, 2003; Ser. No. 60/478,763 filed Dec. 19, 2003; Ser. No. 10/741,868 filed Dec. 30, 2003; all of which are hereby incorporated herein by reference.  
         [0019]     As seen from the figures, port  1  includes one or more attachment mechanisms  70 . The figures herein show three attachment mechanisms all substantially identical and equally spaced from each other. Attachment mechanisms  70  are mounted to the housing  12  at a pivot point  80  along an outer periphery  13  of the housing  12 . As seen from the figures, attachment mechanisms  70  are arcuate hooks pivotable with respect to the housing. Attachment mechanisms  70  have an arcuate length L extending substantially greater than 90°, and preferably at least 180° about the pivot point. Implantable surgical injection port  10  has an undeployed position, shown as a solid line in  FIG. 3 , and a deployed position, shown as the phantom line in  FIG. 3  and in  FIG. 4 , wherein the port is attached to tissue. Attachment mechanisms  70  is preferably made from a bioabsorbable material including, but not limited to, one or more of the following either alone or in combination: iron, polydioxanone, polyglactin and/or poliglecaprone.  
         [0020]     Attachment mechanism  70  has a fixed end  72  pivotally attached to the housing  12  at pivot point  80 . The design allows a surgeon to use forceps and drive the fastener through the tissue until the free end  74  rests against the flat  75 . In this way the patient is protected from the sharp end of the tip. Attachment mechanism  70  also includes a free end  74  which has a sharp or pointed configuration. Housing  12  further includes at least one recessed portion  15  along its distal end  14 . Recessed portion  15  is designed to receive the free end  74  of attachment mechanisms  70  when the port  1  is in its deployed position. This design prevents any exposure of the sharp free end to tissue after the port has been implanted.  
         [0021]     The above described 180° hook or attachment mechanisms provide advantages over prior 90° or less hooks. As seen from  FIG. 4 , the above described attachment mechanism allows the hook to engage a greater area of tissue, and allows for two locking points, entry into and then out of the fascia. This provides for better sacrament of the port to the tissue. Further no “sharp” is exposed to the patient. A further advantage of the fastener configuration is that the fastener follows a constant radius when pushing through the tissue. By maintaining a constant radius the fastener never induces a compressive force onto the fascia. This should minimize pain because the fastener is not “compressing or squeezing” nerves.  
         [0022]     In practice, the physician would create an incision in the skin  110  of a patient to expose the fascia according to well known surgical techniques. Thereafter, as seen from  FIG. 4 , the port  1  could be placed against the fascia  100  of the patient with the port in its undeployed position. Thereafter, the physician could rotate, manually or otherwise, the attachment mechanism substantially greater than 90° and preferably at least 180° so that the hook enters and then exits the fascia. The design allows a surgeon to use forceps and drive the fastener through the tissue until the free end  74  rests against the flat  75 . In this way the patient is protected from the sharp end of the tip. This could be done for each attachment mechanism on the device. Thereafter, the catheter tube  52  would be connected to connection member  30 , and the patient is sewn up.  
         [0023]     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 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 2003/0114729 which is hereby incorporated herein by reference.  
         [0024]     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.