Abstract:
An implantable surgical device including an elongated flexible inflatable portion, an elongated flexible and substantially inextensible band portion. The band portion has a distal end, a proximal end and a longitudinal axis therebetween. The band portion is attached to the inflatable portion along an inner face thereof. The band portion and/or the inflatable portion is at least partially coated with an anti-microbial coating.

Description:
FIELD OF THE INVENTION  
       [0001]    The invention relates to a gastric bands, methods of implanting gastric bands, including the use of robotic assisted surgery, and related accessories. 
       BACKGROUND OF THE INVENTION  
       [0002]    Morbid obesity is a serious medical condition. In fact, morbid obesity has become highly pervasive in the United States, as well as other countries, and the trend appears to be heading in a negative direction. Complications associated with morbid obesity include hypertension, diabetes, coronary artery disease, stroke, congestive heart failure, multiple orthopedic problems and pulmonary insufficiency with markedly decreased life expectancy. With this in mind, and as those skilled in the art will certainly appreciate, the monetary and physical costs associated with morbid obesity are substantial. In fact, it is estimated the costs relating to obesity are in excess of one hundred billion dollars in the United States alone. 
         [0003]    A variety of surgical procedures have been developed to treat obesity. The most common currently performed procedure is Roux-en-Y gastric bypass (RYGB). This procedure is highly complex and is commonly utilized to treat people exhibiting morbid obesity. Other forms of bariatric surgery include Fobi pouch, bilio-pancreatic diversion, and gastroplastic or “stomach stapling”. In addition, implantable devices are known which limit the passage of food through the stomach and affect satiety. 
         [0004]    In view of the highly invasive nature of many of these procedures, efforts have been made to develop less traumatic and less invasive procedures. Gastric-banding is one of these methods. Gastric-banding is a type of gastric reduction surgery attempting to limit food intake by reducing the size of the stomach. In contrast to RYGB and other stomach reduction procedures, gastric-banding does not require the alteration of the anatomy of the digestive tract in the duodenum or jejunum. 
         [0005]    Since the early 1980&#39;s, gastric bands have provided an effective alternative to gastric bypass and other irreversible surgical weight loss treatments for the morbidly obese. Several alternate procedures are performed under the heading of gastric-banding. Some banding techniques employ a gastric ring, others use a band, some use stomach staples and still other procedures use a combination of rings, bands and staples. Among the procedures most commonly performed are vertical banded gastroplasty (VBG), silastic ring gastroplasty (SRG) and adjustable silastic gastric banding (AGB). 
         [0006]    In general, the gastric band is wrapped around an upper portion of the patient&#39;s stomach, forming a stoma that is less than the normal interior diameter of the stomach. This restricts food passing from an upper portion to a lower digestive portion of the stomach. When the stoma is of an appropriate size, food held in the upper portion of the stomach provides a feeling of fullness that discourages over eating. 
         [0007]    However, when items such as adjustable gastric bands and their inflation ports are implanted into the body cavity, the incision point becomes a possible avenue for micro-organisms such as bacteria and virus to enter the body thereby resulting in infection. If the sterility of the materials being implanted is compromised, bacteria may also colonize the implanted device and cause infection. 
       SUMMARY OF THE INVENTION  
       [0008]    An implantable surgical device including an elongated flexible inflatable portion, an elongated flexible and substantially inextensible band portion. The band portion has a distal end, a proximal end and a longitudinal axis therebetween. The band portion is attached to the inflatable portion along an inner face thereof. The band portion and/or the inflatable portion is at least partially coated with an anti-microbial coating. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of the suture tab extender secured to a gastric band. 
           [0010]      FIG. 2  is a perspective view of the removable suture tab extender. 
           [0011]      FIG. 3  is a perspective view of the gastric band secured about the stomach. 
           [0012]      FIGS. 4 ,  5  and  5   a  are various perspective views of a gastric band in accordance with the present invention. 
           [0013]      FIGS. 6 ,  7  and  8  show the various steps in the attachment of the gastric band using the present suture tab extender. 
           [0014]      FIG. 9  is a perspective view of a suture tab extender in accordance with a further embodiment. 
           [0015]      FIG. 10  is a perspective view of a suture tab extender in accordance with an alternate embodiment. 
           [0016]      FIGS. 11 ,  12 ,  13  and  14  respectively show a perspective view of a balloon, a perspective view of a belt, a cross sectional view of a gastric band and a perspective view of the gastric band in accordance with another embodiment of the present invention. 
           [0017]      FIGS. 15 and 16  respectively show a perspective view of a gastric band and a cross sectional view of the gastric band in accordance with an alternate embodiment of the present invention. 
           [0018]      FIG. 17  is a cross sectional view of a gastric band in accordance with another embodiment of the present invention. 
           [0019]      FIGS. 18 ,  19 ,  20  and  21  respectively show a perspective view of a belt, a perspective view of a balloon, a cross sectional view of a gastric band and a perspective view of the gastric band in accordance with yet another embodiment of the present invention. 
           [0020]      FIGS. 22 to 31  show various embodiments of a balloon type gastric band with differing supply tube locations. 
           [0021]      FIGS. 32 to 43  show various embodiments of suture tab extenders with differing attachment structures. 
       
    
    
     DETAILED DESCRIPTION  
       [0022]    The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as the basis for the claims and for teaching one skilled in the art how to make and/or use the invention. 
         [0023]    With reference to  FIGS. 1 and 2 , a removable suture tab extender  100  for use in conjunction with a gastric band  10  is disclosed. The extender  100  is designed to enhance usage of gastric bands  10  and aid with the use of the gastric band latching mechanism  20 . In particular, the extender  100  provides a mechanism for assisting in the passage of the first latching member  22  of the latching mechanism  20  through the second latching member  26  of the latching mechanism  20  by either threading or pushing the first latching member  22  through the second latching member  26  or by inserting a grasper through the second latching member  26 , grasping the tip of the extender  112 , and pulling it back through the second latching member  26  to lock. 
         [0024]    To attach the extender  100  to the gastric band  10 , the tether strap  108  of the extender  100  is threaded through an aperture  38  in the tip of the latching mechanism  20 . This tether strap  108  is then glued to the rest of the extender  100  inside a coupling indent  110 . In accordance with an alternate embodiment, and with reference to  FIG. 10 , the extender  300  may be provided with a pocket  311  positioned at the end of the coupling indent  310  in which the tether strap  308  may be glued. 
         [0025]    The extender  100  is easily removed or cut apart from the gastric band  10  once the gastric band  10  is properly positioned and secured about the stomach, thereby minimizing the risk of “sharp” band edges if the band itself was cut. To remove the extender  100 , the tether strap  108  is cut between the aperture  38  in the tip  36  of the gastric band  20  and the coupling indent  110  containing the glued tether strap  108 . This allows the extender  100  to be removed in one piece, leaving the gastric band  100  completely intact without any “sharp” band edges. 
         [0026]    The extender  100  may further be provided with a recess  109  (see  FIG. 2 ) on the extender  100  for inserting scissors between the tip  36  of the gastric band  20  and the tether strap  108  to better facilitate cutting off the extender  100 . The extender  100  is completely removed from the body after it has been cut off of the gastric band  10 . The extender  100  also allows for the creation of an interim lock permitting adjustment around the stomach before final locking of the latching mechanism  20 . Although a preferred embodiment has the extender cut off for one piece removal from the gastric band body, an alternate embodiment would entail leaving the extender in place on the gastric band and utilizing the interim lock (that is, the retention member  114 ,  214  that is described below in greater detail) as an additional permanent locking position for use with varying stomach sizes. 
         [0027]    In practice, and with reference to  FIG. 3 , the present suture tab extender  100  is secured to the first end  14  of the gastric band  10  adjacent the first latching member  22  to form a single band/extender functional unit. Thereafter, the gastric band  10 , with the extender  100  secured thereto, is inserted behind the stomach. The first latching member  22  of the latching mechanism  20 , as well as the extender  100 , are then pushed or pulled through the second latching member  26  of the latching mechanism  20 . The addition of the present suture tab extender  100  provides a longer region for grasping and manipulation of the first latching member  22  as it is passed about the stomach and through the second latching member  26 . 
         [0028]    In accordance with a preferred embodiment, and as will be discussed below in greater detail, the suture tab extender  100  is an elongated, elastomeric component that attaches to the first end  14  of the gastric band  10  to assist in mating and locking the first latching member  22  with the second latching member  26 . The extender  100  is preferably attached to a tab  24  at the first end  14  of the gastric band  10  to hold the extender  100  in place. The extender  100  is removable with one cut through the tether strap  108  on the extender  100  and incorporates a recess or an open recess, for example, a cuplike feature,  106  for coupling the first end  14  of gastric band  10  and extender  100  close together so as to move as an integral unit. 
         [0029]    More specifically, and as will be greater appreciated based upon the following disclosure, the tab  24  of the gastric band  10  is positioned within the recess  106  of the extender  100  and is safely and securely coupled thereto using a tether strap  108 . In addition, and in accordance with the preferred embodiment, the second end of the extender may include a suture loop  105  for compatibility with a Goldfinger-like device  150 . As those skilled in the art will certainly appreciate, the Goldfinger-like device  150  assists in passing the gastric band  20  through the retro-gastric tunnel. Alternately, for surgeons who use other devices for passing the gastric band  20  through the retro-gastric tunnel, the gripping section, or flat tip,  112  of the extender  100  is compatible with these band-passing devices as well. In general a Goldfinger instrument is an articulating band passing device used to perform blunt dissection behind the stomach before passing the gastric band. It is articulated and fed behind the stomach. In the tip of the Goldfinger instrument there is a notch that a suture loop can catch on. Once the suture is caught, the Goldfinger instrument is pulled out of the retro-gastric tunnel and the suture loop pulls the band with it. Alternately, to facilitate use with these other band passing-devices, a length of the extender may be round (like tubing) behind the flat tip so that the extender is easier to orient. 
         [0030]    The removable extender  100  is designed for use with a variety of gastric bands. By way of example, the extender is designed for use with gastric bands as disclosed in commonly owned U.S. patent application Ser. No. 11/182,072, filed Jul. 15, 2005, entitled “LATCHING DEVICE FOR GASTRIC BAND”, which is incorporated herein by reference. 
         [0031]    In general, and with reference to  FIGS. 4 ,  5  and  5   a,  the gastric band  10  includes a band body  12  having a first end  14  and a second opposite end  16 . The band body  12  and latching mechanism  20  are preferably manufactured from silicone. Although, and as will be discussed below in greater detail, the gastric band is a balloon type gastric band, the present latching mechanism may be used in conjunction with a variety of band structures without departing from the spirit of the present invention. 
         [0032]    As briefly mentioned above, the gastric band  10  is shaped and dimensioned to circumscribe the stomach at a predetermined location reducing the size of the stomach. The gastric band  10  employs a flexible latching mechanism  20  capable of locking and unlocking without destruction of the latching mechanism  20  or significant reduction in retention capabilities after re-locking. The first and second ends  14 ,  16  respectively act as both male and female members depending on the direction of motion and intent to lock or unlock the latching mechanism  20  of the present gastric band  10 . 
         [0033]    The first end  14  includes a shell member, or first latching member,  22  generally composed of a hollow, half-moon shaped shell with a tab  24  for gripping and pulling through a collar member, or second latching member,  26  composed of a semi-circular shaped aperture  30  on the second end  16 . The half-moon shell of the first latching member  22  collapses as it is pulled or pushed through the collar member  26  by a grasper. The collar member  26  includes a tongue  28  such that the shell member  22  slides through the semi-circular shaped aperture  30  and under the tongue  28  during latching. Once the shell member  22  passes the tongue  28 , the roles change. The first end  14  functions as a female component when the shell member  22  resiliently returns to its original shape and is allowed to slide back onto the second end  16  (now a male component) and over the tongue  28 . As such, the shell member  22  functions as both a male component and female component during operation of the latching mechanism  20  and the collar member  26  functions as both a male component and female component during operation of the latching mechanism  20 ; that is, the shell member  22  functions as a male component during insertion through the collar member  26  and a female component thereafter when the tongue  28  is seated therein. Unlocking is achieved by employing graspers to pull the first end  14  forward away from the second end  16  removing the tongue from the shell member  22 . The M-shape of the shell member  22  permits it to collapse and move under the tongue  28  and through the collar member  26 . 
         [0034]    More particularly, the shell member  22  at the first end  14  of the gastric band  10  is generally a half-moon shaped shell with an open, wide end  32  tapering toward a narrow end  34  adjacent the tip  36  of the first end  14 . The shell member  22  is substantially hollow and is formed from a material, for example, silicone, which permits compression and expansion thereof. 
         [0035]    Referring to  FIG. 5   a,  the shell member  22  is formed with a substantially M-shaped outer surface  23   a  when viewed from the wide end  32  thereof. That is, the outer surface of the shell member  22  has a substantially M-shaped profile, while the inner surface  23   b  of the shell member  22  adjacent the wide end  32  has a substantially smooth semi-circular profile. The single M-shaped profile has been found to improve flexibility and control as the shell member  22  is passed through the collar member  26 . In addition, the inclusion of the M-shape in the wide end  32  of the shell member  22  permits ease of unlocking as it will be easier and more controllable for one to compress the shell member  22 . 
         [0036]    The shell member  22  is slid through the collar member  26  as discussed above. Thereafter, the center  54  of the M-shaped wide end  32  returns to its original shape and fits over the tongue  28 . When the gastric band  10  is unlatched, the shell member  22  is pulled forward away from the collar member  26  and the M-shaped shell member  22  permits it to move under the tongue  28  and through the collar member  26 . The preformed shape of the shell member  22  not only acts as a guiding feature for the tongue  28  to slide over the shell member  22  during unlocking, but will also allow the shell member  22  to more easily slide back through the aperture  30  of the collar member  26 . 
         [0037]    An aperture  38  is formed within the tab  24  adjacent the tip  36  of the first end  14  and the narrow end  34  of the shell member  22 . The aperture  38  is shaped and dimensioned for receipt of a suture or grasper commonly used in the installation of gastric bands. In addition, the tab  24  is formed with protrusions  39  assisting in grabbing the tab  24  during locking and unlocking. 
         [0038]    Also at the first end  14 , but on the opposite side of the shell member  22  from the aperture  38  and adjacent the wide end  32  of the shell member  22  is a rearwardly extending gripping member  51 . The gripping member  51  is shaped and dimensioned to permit dual directional access for locking and unlocking of the latching mechanism  20 . More particularly, the gripping member  51  includes protrusions  56  along the top and bottom surfaces  53 ,  55  thereof. These protrusions facilitate gripping thereof along a first directional orientation. The gripping member  51  is further formed with an “hour glass” shape having a reinforced central section  57 . The reinforced central section  57  allows for gripping in a second directional orientation. 
         [0039]    Secure fastening of the shell member  22  with the collar member  26  is achieved by ensuring that after the shell member  22  compresses while passing through the collar member  26 , the shell member  22  returns to its original shape and the wide end  32  of the shell member  22  abuts with the first edge  46  of the collar member  26 . 
         [0040]    Latching is further enhanced by providing the collar member  26  with a tongue  28  extending from the collar member  26  away from the tip  50  of the second end  16 . The tongue  28  is shaped and dimensioned to seat within the wide end  32  of the shell member  22  after the shell member  22  has passed through the collar member  26  and the gastric band  10  is tensioned as the first and second ends  14 ,  16  are drawn toward each other with the shell member  22  straining to move back through the collar member  26  toward an unlatched positioned. With this in mind, the tongue  28  may be downwardly oriented such that it slides with the shell member  22  in a convenient and reliable manner. The tongue  28  may be distinctly colored to provided an indication as to whether the latching mechanism  20  is properly locked. 
         [0041]    Gripping of the second end  16  is further enhanced through the provision of a forward facing gripping member  58 , that is, a gripping member facing the tip  50  of the second end  16 . The forward facing gripping member  58  is shaped and dimensioned to permit dual directional access for locking and unlocking of the latching mechanism  20 . More particularly, the gripping member  58  includes protrusions  59  along the top and bottom surfaces  62 ,  64  thereof. These protrusions  59  facilitate gripping thereof along a first directional orientation. The gripping member  58  is further formed with an “hour glass” shape having a reinforced central section  60 . The reinforced central section  60  allows for gripping in a second directional orientation. 
         [0042]    The gripping member  58  is shaped and dimensioned to receive and center the shell member  22  as it passes through the collar member  26 . The gripping member  58  also assists in compressing the shell member  22  as it passes through the collar member  26 . 
         [0043]    In accordance with a preferred embodiment of the present invention, the gastric band is a balloon-type gastric band as shown in  FIGS. 11 to 16 . With this in mind, the gastric band  410  is generally composed of a substantially inextensible band portion or reinforcing belt  412  to which an elongated inflatable portion or balloon  414  is secured. The belt  412  includes a first end  416  and a second end  418  to which the first and second latching members  422 ,  426  are respectively secured. The belt  412  further includes an inner surface  428  and an outer surface  430 . The outer surface  430  is substantially smooth and forms a substantial portion of the outer surface  431  of the gastric band  410  when it is secured about a patient&#39;s stomach. The inner surface  428  of the belt  412  is shaped and dimensioned for attachment to the outer surface  438  of the balloon  414 . 
         [0044]    With regard to the balloon  414 , it also includes a first end  432 , a second end  434 , an inner surface  436  and an outer surface  438 . The inner surface  436  is substantially smooth and is shaped and dimensioned for engaging the patient&#39;s stomach when the gastric band  410  is secured thereto. The outer surface  438  of the balloon  414  is shaped and dimensioned for coupling with the inner surface  428  of the belt  412 . 
         [0045]    Referring to  FIGS. 11 to 16 , the belt  412  and balloon  414  may be respectively coupled by either overmolding or separate molding with subsequent adhesive bonding (similar numerals are used for the different embodiments). Regardless of the manufacturing technique, the outer surface  438  of the balloon  414  is formed with a groove  439  shaped and dimensioned for receiving the belt  412 . Referring to  FIGS. 15 and 16 , wherein the belt  412  is adhesively bound to the balloon  414 , the groove  439  is formed with a glue gap  439   a  shaped and dimensioned for receipt of a small amount of adhesive without adversely affecting the position of the belt  412  within the groove  439 . 
         [0046]    In accordance with an alternate embodiment, and with reference to  FIG. 17 , it is contemplated the balloon  414 ′ and the belt  412 ′ may be coupled by adding a layer of uncured material  413 ′ (similar in composition to components) between the balloon  414 ′ and belt  412 ′, and curing them together. In addition, a layer of reinforcing structure  415 ′ (mesh, dissimilar material, or higher durometer silicone material) is contained within the layer of uncured material  413 ′. This reinforcing structure  415 ′ is encapsulated within the device upon assembly and curing, and provide additional structure or different mechanical properties to the product. 
         [0047]    In addition, and with reference to  FIGS. 18 to 21 , yet a further gastric band  410 ″ construction is contemplated in accordance with the present invention. In accordance with this embodiment, the belt  412 ″ is secured along an internal surface  417 ″ of the balloon  414 ″, with the outer surface  428 ″ of the balloon  414 ″ forming the exposed outer surface  430 ″ of the gastric band  410 ″. As with the embodiments disclosed above, the internal surface  417 ″ is formed with a groove  439 ″ shaped and dimensioned for receiving the belt  412 ″. Secure positioning of the belt  412 ″ within the groove  439 ″ is achieved through provision of a glue gap  439   a ″ along the groove  439 ″ and a retaining snap  439   b ″ along the length of the groove  439 ″. The glue gap  439   a ″ is substantially similar to that employed in accordance with the embodiment disclosed with reference to  FIGS. 16 and 17 . 
         [0048]    As to the retaining snap  439   b ″, the groove  439 ″ is constructed with opposed, inwardly directed protrusions  439   c ″ shaped and dimensioned to engage the belt  412 ″, and temporarily retain the belt  412 ″ within the groove  439 ″, while the glue used to couple the belt  412 ″ and balloon  414 ″ cures during the gluing operation. More particularly, the inwardly directed protrusions  439   c ″ are shaped and dimensioned to wrap about the belt  412 ″ in a manner holding it within the groove  439   c″.    
         [0049]    In accordance with a preferred embodiment, the belt  412 ″ is positioned within the balloon  414 ″ in the following manner. The belt  412 ″ is threaded through one of the balloon openings  433 ″,  435 ″ on either end  432 ″,  434 ″ of the balloon  414 ″. The retaining snap  439   b,  specifically protrusions  439   c ″, on the groove  439  of the balloon  414 ″ temporarily hold the components together while they are being glued via a long needle inserted between the balloon  414 ″ and the belt  412 ″. Alternately, it is contemplated the balloon can be overmolded onto the belt. 
         [0050]    In accordance with preferred embodiments, and as briefly discussed above, the balloon and belt may be secured together by either adhesive bonding, comolding, overmolding or mechanical connection (for example, coupling sleeves), which secures the balloon and belt in a manner resulting in the coupling of these distinct gastric band components. Where the belt and balloon are overmolded, a plug  415  would be used to close the core outlet in the balloon for the overmold and the plug  415  would be integral to the gastric band structure (see  FIGS. 14 &amp; 15 ). As those skilled in the art will certainly appreciate, co-molding is essentially the same procedure as overmolding, but materials of different properties are shot in the mold at the same time. As with overmolding, comolding requires a plug to close the core outlet in the balloon. 
         [0051]    Regardless of how the product is molded or assembled together, the belt and balloon components may consist of the same materials or different materials (material durometer, fillers such as BaSO 4 , TiO 2 , colorants, etc.). In addition, features within the same component (i.e. the locking features or end caps) may vary in composition. These features may be adhered to the rest of the product with adhesive, mechanical fastening (i.e., snap fits), welding, co-molding, or overmolding. Although the belt is disclosed as being secured to an outer surface of the balloon, it is contemplated the belt may be internal or external to the balloon surface or integrated into the balloon, without departing from the spirit of the present invention. 
         [0052]    For assembly methods allowing the adherence of different components (that is, adhesive bonding, mechanical connection, overmolding), unique belt and balloon components may be combined to provide variable configurations. For example, belts with different locking mechanisms may be interchanged with balloons of different lengths to provide the possibility of multiple combinations of products. 
         [0053]    The balloon  414  is constructed to enhance contact with the stomach wall when applied thereto. With this in mind, and as will be discussed below in greater detail, the balloon  414  is constructed as a precurved, low pressure, high volume balloon. The balloon  414  is constructed to maintain a soft and flexible surface (low pressure) when applied to the stomach tissue. The balloon  414  is also constructed to provide 360 degree coverage to prevent tissue pinching or discontinuities in stomach shape, and, as such, may employ the balloon construction disclosed in commonly owned U.S. patent application Ser. No. 11/182,070, entitled “GASTRIC BAND WITH MATING END PROFILES”, filed Jul. 15, 2005, which is incorporated herein by reference. The balloon  414  is further constructed such that it reaches it fully inflated and encircling configuration with minimal “folds”. In addition, the balloon  414  is constructed to exhibit no folds or creases (single axis, not dual axis) when all fluid is evacuated therefrom. 
         [0054]    With the foregoing in mind, the balloon  414  employed in accordance with a preferred embodiment of the present application is constructed of an elastomeric material. Due to the design of this balloon, it does not inflate or expand in a manner causing high strain in balloon when filled during gastric band adjustment. Rather, the balloon  414  is adapted to receive a large volume of fluid under a relatively low pressure. In this way, the balloon  414  receives fluid during application, but does not inflate or expand in a traditional manner creating strain along the walls of the balloon  414 . In other words, when the balloon  414  is filled up to the volume recommended to achieve maximum stomach restriction, there is no expansion of the balloon material. Instead, the balloon  414  fills to some percentage of its total theoretical volume (that is, maximum fill volume). Since the balloon  414  is not filled even close to its maximum fill volume, it remains low pressure, allowing the balloon  414  to conform to the stomach rather than the stomach to a rigid balloon. 
         [0055]    In accordance with a preferred embodiment of the present invention, the balloon  414  is designed with a maximum capacity of between approximately 10 cc and approximately 18 cc, and preferably 18 cc, although it will be fully filled for functioning in accordance with the present invention to achieve the smallest stoma size with approximately 9 cc to approximately 12 cc, and preferably 9 cc. By providing a balloon  414 , which is not at its capacity when properly filled for functioning, the softness and conformance of the balloon is improved. While specific volumes are disclosed in accordance with a preferred embodiment of the present invention, those skilled in the art will appreciate the filling volumes may be varied without departing from the spirit of the present invention. 
         [0056]    In addition, the balloon  414  is fabricated such that it exhibits a curved configuration when unstressed. Although a variety of curvatures are possible within the spirit of the present invention, the curved configuration is designed to offer a radius of curvature of approximately 0.5 inches to approximately 1.5 inches. In addition, it is contemplated the balloon may have a varying radius as it extends about its length. In general, the balloon curvature is designed to approximate the curvature required to bring the first and second latching members  422 ,  426  into approximation or contact when the balloon  414  is unbiased and left to assume a relaxed configuration. By fabricating the balloon  414  with an inherent curvature, folds created upon the application of fluid are substantially decreased. With this in mind, the belt is similarly pre-curved to reduce folds and approximate the first and second latching members  422 ,  426 . 
         [0057]    As those skilled in the art will certainly appreciate, the belt  412  is constructed to have a curvature approximately the same that of the balloon  414  such that undesirable tension between the belt  412  and balloon  414  is reduced. In addition, and in consideration of the precurved nature of the belt  412 , the belt  412  readily conforms to the outer surface of the stomach and the belt  412 . 
         [0058]    Contact with the stomach tissue is further enhanced by providing the balloon  414  with a concave cross-section along the balloons inner surface  436 . This cross sectional configuration helps to facilitate evacuation and straightening thereof. 
         [0059]    By implementing the structural criteria outlined above, the balloon  414  deflates with no creases or bulges forming on the inner surface  436  of the balloon  414 , a low pressure and pre-curved balloon  414  is achieved and the balloon  414  changes shape when it is filling (zip-lock bag filling up). As to the change in shape, the balloon  414  is constructed such that it has a relatively wider and flatter cross section prior to filling along a cross section transverse to the longitudinal axis of the balloon  414 . When the balloon  414  is subsequently filled during application to the stomach of a patient, the transverse cross sectional shape of the balloon  414  changes to that of a rounder balloon exhibiting a narrower cross section with a greater distance between the inner and outer surfaces  436 ,  430  thereof. With this in mind, it is further contemplated that the balloon cross section may be molded in a rounded rectangular shape, wherein the “corners” provide support, distribute the change in shape and reduce folds. By providing a balloon which is wide and flat prior to filling, the distance between the inner surface of the balloon and the belt is reduced. This reduces the ultimate profile of the gastric band and improves the ability of the gastric band to be readily delivered for deployment. 
         [0060]    As those skilled in the art will certainly appreciate, a supply tube is used to connect the internal cavity of the balloon of the gastric band with a pressurized fluid source. The utilization of the tube with a remote fluid source allows for controlled inflation and deflation of the balloon in a predetermined manner. The exact position of the tube is important in that the surgeon does not want tubing to be a visual obstruction during locking and/or other manipulation of the gastric band. In addition, once placement of the gastric band is complete, the tube should not cause irritation to surrounding tissue (for example, sticking directly into the liver or spleen). Surgeons also do not want to pull the tube through a retro-gastric tunnel, since they cannot easily see if the tissue is being damaged. The tube should also be able to act as a safe grasping location for manipulation of the gastric band, the tube must not kink at the junction to the gastric band and prevent fluid flow, and the tube location should facilitate passage of the band through a small trocar. 
         [0061]    With this in mind, and in accordance with various preferred embodiments of the present invention, different tube placements are shown with reference to  FIGS. 22 to 31 . As each these various embodiments show, the tube is positioned at an end of the gastric band. By positioning the tube at an end of the gastric band it has been found that forces upon the tube, gastric band, and, ultimately the stomach, are reduced. This positioning also enhances the ability of the tube and gastric band to flex for insertion and expand to its original shape upon deployment. 
         [0062]    Referring to  FIG. 22 , the tube  540  is oriented to exit the gastric band  510  from the outer surface thereof. In accordance with a preferred embodiment of this design, the tube  540  is positioned such that is comes out the outer surface  531  of the gastric band  510  just below a longitudinally extending midline  542  of the gastric band  510 . The tube  540  is positioned so that is placed clear of the latching mechanism  520  and obliquely angled relative to the longitudinal axis (in accordance with a preferred embodiment at an angle of approximately 34°) of the gastric band  510  to allow easy insertion through a trocar. 
         [0063]    Referring to  FIG. 23 , the tube  640  is molded on the second end  634  of the balloon  614 . In particular, the tube  640  is molded at the very end of the balloon  614 , and is integrated into the balloon shape. As with the prior embodiment, the tube  640  is obliquely oriented relative to the longitudinally axis of the gastric band  610  and is similarly positioned below a longitudinally extending midline of the gastric band  610 . The offset allows for the balloon ends  632 ,  634  to meet without interference from the tube  640 . 
         [0064]    A further embodiment is shown with reference to  FIG. 24 , wherein the tube  740  exits the balloon  714  off a lateral side  744 , that is, a very bottom surface, of the balloon  714  as it is positioned within the patient. The tube  740  entry point is substantially aligned with the second latching member  726  relative to the longitudinal axis of the gastric band  710 . As with the prior embodiments, the tube  740  is obliquely oriented relative to the longitudinally axis of the gastric band  710 . 
         [0065]    As shown in  FIGS. 25 and 26 , the tube  840  connection is integrated into one of the sides of the latching members. In accordance with the disclosed embodiment, it is integrated into the second latching member  826 , although it is contemplated it could be integrated with the first latching member  822  without departing from the spirit of the present invention. The tube  840  enters the second latching member  826  and extends therethrough into the body of the balloon  814 . Once the tube  840  is inside the body of the balloon  814 , it angles to the centerline (or midline  842 ) of the balloon  814  for even filling of saline. The tube  840  is also obliquely oriented relative to the longitudinally axis of the gastric band  810  and is similarly positioned below a longitudinally extending midline  842  of the gastric band  810 . The offset allows for the balloon ends  832 ,  834  to meet without interference from the tube  840 . 
         [0066]    Yet other embodiments are shown respectively with reference to  FIGS. 27 and 28 . In accordance with one embodiment as shown in  FIG. 27 , the tube  940  is molded into the plug  946  used to cap the core portion of the balloon  914 . In accordance with the other embodiment as shown in  FIG. 28 , the tube  1040  is molded as an integral portion of the second latching member  1026 . The fluid passageway, therefore, extends through the tube  1040 , into passageways  1048  formed in the second latching member  1026  and ultimately into the balloon  1014 . More particularly, once the tube  1040  enters into a bridge of the second latching member  1026  (that is, where the second latching member  1026  defines the aperture), it splits into a bifurcated tube  1052  that goes into the balloon  1014  via both walls  1054  of the aperture  1030  of the second latching member  1026 . 
         [0067]    Still another embodiment is shown in  FIGS. 29 and 30 , wherein the tube  1140  is integrated into one of the sides of the latching mechanism  1120 , preferably, the second latching member  1126 . The tube  1140  then runs through a gusset  1156  from the back of the second latching member  1126  to allow for a low entry angle into the balloon  1114 . 
         [0068]    Referring to  FIG. 31 , the tube  1240  entry is integrated into the belt  1212  (and more particularly, the second latching member  1226 ) to allow for separate molding of the belt  1212  and balloon  1214 . By being attached to the second latching member  1226 , the tube  1240  could be used to find the location of the latching mechanism  1220  once the implant has been encapsulated into the fibrous tissue. As with the prior embodiments, the tube  1240  is obliquely oriented relative to the longitudinally axis of the gastric band  1210  and is similarly positioned below a longitudinally extending midline  1242  of the gastric band  1210 . The offset allows for the balloon ends  1234  to meet without interference from the tube  1240 . 
         [0069]    In addition, any of the tubing configurations disclosed with reference to  FIGS. 22 through 31  could incorporate some type of strain relief member to reduce fatigue as the tubing flexes back and forth in the body. Such strain relief would be achieved by positioning a length of thicker material at the tubing entry point into the balloon (see for example  1156  on  FIG. 29 , similarly shown but not called out in  FIG. 31 ). The length of thicker material allows the tubing to take a larger curve as it is bent away from the joint between the tube and the balloon. In other words, this length of material that has been thickened increases the stiffness of the tubing in this region to allow the tubing to flex without kinking and moves the point of flexing further away from the vulnerable joint between the band, balloon, and tubing. The strain relief member would be made preferably of silicone, but other materials (plastics, metals, etc.) could also be used. Also, in all of these embodiments, the tubing to could be connected to either the belt or the balloon by any one of multiple manufacturing methods, such as overmolding or assembling and gluing. 
         [0070]    Although the present invention is described for use in conjunction with gastric bands, those skilled in the art will appreciate 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. Bands can also be used to treat urinary incontinence. One such band is described in U.S. Patent Application Publication No. 2003/0105385. 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. Bands can also be used to treat impotence. One such band is described in U.S. Patent Application Publication No. 2003/0114729. 
         [0071]    Referring to  FIGS. 1 and 2 , the extender  100  includes an elongated body member having a first end  102  and second end  104 . The first end  102  includes an open recess  106  shaped and dimensioned to receive the tab  24  of the first latching member  22  at the first end  14  of the gastric band  10 . The first end  102  of the extender  100  is further provided with a tether strap  108 . The tether strap  108  is shaped and dimensioned for passage through the aperture  38  formed in the tab  24  and ultimate attachment within a coupling indent  110  formed in the outer surface of the first end  102  of the extender  100 . In this way, the tether strap  108  extending from the extender  100  loops through the tab  24  readily coupling the first end  102  of the extender  100  the first latching member  22  for selective attachment and detachment. 
         [0072]    The second end  104  of the extender  100  includes a gripping section  112  shaped and dimensioned to facilitate gripping thereof as the extender  100  is passed through the collar member  26  and the gastric band  10  is applied around a patient&#39;s stomach. In addition, there is a suture loop  105  for compatibility with Goldfinger instruments  150  as discussed above and the gripping section, or flat end,  112  of the extender  100  is compatible with other band passing devices. Between the first end  102  and the second end  104  of the extender  100  is formed a laterally extending retention member  114 . The retention member  114  is semi-circular when viewed along a planar, transverse cross section. The retention member  114  tapers to widen as it extends toward the first end  102  of the extender  100  in a manner creating a surface over which the collar member  26  may slide during latching for interim attachment of the extender  100  to the collar member  26 . The taper creates an engagement surface  118  which holds the collar member  26  between the enlarged first end  102  of the extender  100  and the retention member  114  when the first end  102  of the extender  100  is temporarily latched to the collar member  26 . 
         [0073]    Although an extender with a recess and retention member in accordance with a preferred embodiment is disclosed above, the extender may take other forms without departing from the spirit of the present invention. For example, and in accordance with another preferred embodiment shown with reference to  FIG. 9 , the extension member  200  includes an elongated body member having a first end  202  and second end  204 . The first end  202  includes an enclosed, pocket recess, more particularly a pocket,  206  shaped and dimensioned to fully receive the tab  24  of the first latching member  22  at the first end  14  of the gastric band  10 . The first end  202  of the extension member  200  is further provided with a tether strap  208 . The tether strap  208  is shaped and dimensioned for passage through the aperture  38  formed in the tab  24  and ultimate attachment within a coupling indent  210  formed in the outer surface of the first end  202  of the extension member  200 . In this way, the first end  202  of the extension member  200  may be readily and selectively secured and detached from the first latching member  22 . 
         [0074]    The second end  204  of the extension member  200  includes a series of protrusions  212  shaped and dimensioned to facilitate gripping thereof as the extension member  200  is passed through the collar member  26  and the gastric band  10  is applied around a patient&#39;s stomach. The second end  204  also includes a suture loop  205  extending therefrom. Between the first end  202  and the second end  204  of the extension member  200  is formed a laterally extending retention member  214 . The retention member  214  includes first and second engagement members  216 ,  218 . The engagement members  216 ,  218  are tapered to widen as they extend toward the first end  202  of the extension member  200  in a manner creating a surface over which the collar member  26  may slide during latching for interim attachment of the extension member  200  to the collar member  26  prior to complete latching of the gastric band  10  latching mechanism  20  (after which the extension member  200  is detached from the gastric band  10 ). The taper creates opposed engagement surfaces  220 ,  222  which hold the collar member  26  between the enlarged first end  202  of the extension member  200  and the engagement members  216 ,  218  when the first end  202  of the extension member  200  is temporarily latched to the collar member  26 . 
         [0075]    Regardless of the extender construction utilized in accordance with a gastric band, it is important the extender be readily accessed for removal with little possibility for error. The two key issues in removal of an extender revolve around a surgeon&#39;s ability to identify the extender, in particular, that part of the extender requiring manipulation for removal thereof, and proceed to remove the extending in accordance with the removal mechanism employed. With this in mind, various embodiments for ensuring clear visualization and convenient cutting have been developed. Any of the embodiments described below can incorporate a visual indicator such as color (on either the entire extender, the tether strap, or the only the region to be cut) or a visible suture to indicate to the surgeons that this is a separate component from the gastric band that should be removed. In addition, these embodiments also provide various means in which the extender may be attached to the gastric band (tether strap, suture, etc.). 
         [0076]    More particularly, and with reference to  FIGS. 32 ,  33   35  and  36 , the extender  1300  adjacent the first end  1302  thereof or the tether strap  1508 ,  1608  of the extender  1500 ,  1600  is provided with one or more bumps or ramps  1330 ,  1530 ,  1630  at a location adjacent the open coupling indent, or pocket,  1310  into which the tether strap  1308 ,  1508 ,  1608  of the extender  1300 ,  1500 ,  1600  is to be positioned. By providing a bump or ramp  1330 ,  1530 ,  1630  at this position (on either the first end of the extender or on the tether strap), the tether strap  1308 ,  1508 ,  1608  is held above the first end  1302  and the surgeon is able to readily visualize the location of the tether strap  1308 ,  1508 ,  1608 . The bump or ramp  1330 ,  1530 ,  1630  location is at a position adjacent the point at which the tether strap  1308 ,  1508 ,  1608  is to be cut for removal of the extender  1300 ,  1500 ,  1600  and, therefore, provides the surgeon a visual indicator as to the cut location. In accordance the embodiment shown with reference to  FIG. 35 , two bumps  1530   a,    1530   b  wrap completely around the tether strap  1508  and define an area at which a surgeon should cut the tether strap  1508 . 
         [0077]    In addition to improving visualization of the tether strap, in each embodiment the bumps or ramp raise the tether slightly above the gastric band, increasing the space between the tether and the gastric band to provide an improved passageway for position scissors therein for cutting of the tether and ultimate removal of the extender. Visualization of the cutting location in accordance with this embodiment is enhanced by providing a gap or a notch  1332 ,  1432 ,  1532  along the tether strap  1308 ,  1408 ,  1508  (see  FIGS. 32 ,  33 ,  34  and  35 ). In particular and with reference to  FIGS. 32 ,  33  and  43 , the suture loop at the second end of the extender  1300 ,  2200  is continued throughout the body of the extender  1300 ,  2200  with the suture  1334 ,  2234  extending through the tether strap  1308 ,  2208  and functioning as a reinforcing member. However, a portion of the suture  1334 ,  2234  is exposed along the tether strap  1308 ,  2208  at a predetermined location such that when the tether strap  1308 ,  2208  is passed through aperture  38  of the gastric band tab  24  and wrapped about the gastric band  10  to secure the two components together, the gap  1332 ,  2232  is positioned at the desired location for cutting. 
         [0078]    Similarly, and as is seen if  FIGS. 34 and 35 , the tether strap  1408 ,  1508  may have a localized region that is smaller than the remainder of the tether strap  1408 ,  1508  allowing for cutting in a single step. More particularly, the localized region is preferably a notch  1432 ,  1532  formed along the tether strap  1408 ,  1508 . In addition, because the gap or notch  1432 ,  1532  is readily differentiated based upon its physical appearance from the remainder of the tether  1408 ,  1508 , a surgeon may easily identify the location requiring cutting. It is contemplated either the notch or gap design could be used in conjunction with the bump described above with reference to  FIGS. 32 ,  33 ,  36 ,  42  and  43 , although these designs could certainly be employed without the bump where certain design considerations dictate. 
         [0079]    Other embodiments are disclosed with reference to  FIGS. 37 ,  39  and  40 . These embodiments employ a reinforcing member, for example, a suture  1734 ,  1934  to aid in the connection of the extender  1700 ,  1900  to the tip of the gastric band. In one application (see  FIG. 37 ), the suture  1734  holds the tether strap  1708  down upon the body thereof. As such, and rather than cutting the tether strap  1708  itself as disclosed above with reference to the various embodiments, the securing suture  1734  is cut to thereby release the tether strap  1708  for removal of the extender  1700 . Alternately, the suture may be used to tie down the strap and as such, secure the tether to the extender without the assistance of adhesive. Although a suture is disclosed as a reinforcing member in accordance with a preferred embodiment, other reinforcing structures, for example, mesh, may be used within the spirit of the present invention. 
         [0080]    In another related embodiment shown in  FIGS. 39 and 40 , the suture material of the suture loop  1905  is extended to run the length of the extender  1900  such that the suture material  1934 , extends from the first end  1902  of the extender  1900  (substantially replacing the tether of the prior embodiments). This allows the extender  1900  to wrap a suture  1934  through an aperture  38  in the tip of the gastric band  10  and engage a projection  1936  extending from the first end  1902  of the extender  1900 . In addition to securing the gastric band in a reliable and convenient manner, this embodiment provides additional benefits in that the suture  1934  now has a loop at the first end  1902  and the second end  1904  of the extender  1900 . This increases the strength of the extender  1900  because the suture cannot pull out of the extender independent of extender material failure. 
         [0081]    Referring to  FIG. 38 , another embodiment is disclosed. In accordance with this embodiment, the tip  1812  of the gastric band  1810  is seated within the recess  1806  formed in the extender  1800 . However, the recess  1806  and the tip  1812  of the gastric band  1810  include a snap feature providing a semi-mechanical locking mechanism between the gastric band  1810  and the extender  1800 . Such an embodiment would improve the ability of the extender  1800  to lead and guide the tip  1812  of the gastric band  1810  in concert without twisting or flipping. Such a semi-mechanical locking mechanism could be utilized in conjunction with the other tether securing arrangements as a means for providing redundant securing of the extender to the gastric band. It is further contemplated this embodiment may have suture  1811  around the tip  1812  of the gastric band  1810  and the recess  1806  of the extender  1800  (like  FIG. 37 ) to compress the region where the snap fitting tip  1812  fits within the recess  1806  of the extender  1800 . When the surgeon cuts and removes the surrounding suture  1811 , they can then expand the flexible silicone extender  1800  over the snap fitting tip  1812  on the front of the tab to separate the extender  1800  from the gastric band  1810  in one piece. 
         [0082]    Further and with reference to  FIG. 41 , a suture  2034  is similarly utilized in securing the extender  2000  to the gastric band. However, the projection  2036  to which the extender  2000  is secured is designed such that it may be peeled away. As such, when it is desired to remove the extender  2000 , one need only peel away the projection  2036  to release the extender  2000  and thereby no cutting is required. 
         [0083]    Referring to  FIG. 42 , another embodiment is disclosed. In accordance with this embodiment, the tether  2108  of the extender  2100  is lengthened to allow the glue position  2138  to be moved a forward position on the open recess  2106  extender  2100 . This allows the tether  2108  of the extender  2100  to be cut at line  2140  to remove the extender  2100 . More particularly, the open recess  2106  includes a forward and  2106   a  positioned toward the middle of the extender  2100  and a rearward position  2106   b  positioned near the first end  2102  of the extender  2100 . The glue position  2138  is at the forward end  2106   a.  This is still a one-piece removal, only the length of the location for cutting has changed. This embodiment allows the tether  2108  to bow for improved access with scissors or other tools when the front of the extender is flexed upwardly since the tether is only glued at one end  2106   a.    
         [0084]    In accordance with yet another embodiment, and with reference to  FIG. 43 , a flange or stopper  2242  is positioned at a preset point along the length of the tether  2208 . This enables positioning of the gap  2232  in the tether  2208  relative to the position of the extender  2200  where the suture  2234  needs to be cut and to avoid having suturing contact with the gastric band hole during band pulling. The stopper  2242  is positioned to engage the tab surrounding the aperture so as to limit the extent to which the tether  2208  may pass therethrough. The portion of the tether  2208  adjacent the stopper  2242  may be tapered and the section that is positioned inside the aperture of the gastric band can be larger in cross section to provide a snug fit with the hole of the gastric band. As with prior embodiments the tether will includes a gap or notched section for identification and cutting thereof. In addition, the suture loop runs fully through the extender and may be utilized by tying it into a knot that is molded within the enlarged section of the stopper so as to improve the strength of the extender tether. 
         [0085]    When devices such as adjustable gastric bands are implanted into the body cavity, the incision point becomes a possible avenue for micro-organisms such as bacteria and virus to enter the body thereby resulting in infection. If the sterility of the materials being implanted is compromised, bacteria may also colonize the implanted device and cause infection. This can be overcome by coating them with antimicrobial agent. The above described gastric band can be coated with anti-microbials such as silver sulfadiazine and pipericillin. This will drastically reduce the infection rate and the mortality associated with it. The coating is not visible to the naked eye and is therefore not shown explicity in the figures. However, it is contemplated that the outersurfaces of the inextensible band portion or reinforcing belt  412  and the elongated inflatable portion or balloon  414  could be coated as well as the latching members  422 ,  426 . In addition, the supply tube used to connect the internal cavity of the balloon of the gastric band with a pressurized fluid source could be coated as well. 
         [0086]    The standard method of application of these antibiotics is by dipping the device into a solution of antimicrobial agent and allowing it to cover the surface. Other methods are to dissolve the agent into a permeable polymer barrier and dipping the device into the solution. 
         [0087]    Another common antimicrobial agent used for this type of application is chlorhexidine acetate or gluconate. In its basic state, this anti-microbial agent has low solubility in water. When reacted with a weak acid, the salt form is readily soluble in water. Chlorhexidine is applied onto the implantable medical device and then converted into its free-base form so that its release is slow but steady. Implantable bariatric devices such as ports, bands, inflatable balloons, staples and clips that stay in the body for a long time could be coated with anti-microbial agents to reduce bacteria colonization. 
         [0088]    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. 
         [0089]    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.