Patent Publication Number: US-2010114311-A1

Title: Multi-Lumen Breast Prothesis and Improved Valve Assembly Therefor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 61/111,440, filed Nov. 5, 2008, entitled “Multi-Lumen Breast Prosthesis and Improved Valve Assembly Therefrom”. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a multi-lumen breast prosthesis and improved valve and seal assembly for such prosthesis and more particularly to a multi-lumen breast prosthesis of the type having an outer lumen, a mass of gel disposed in the outer lumen and an inner lumen and a mass of saline disposed in the inner lumen. The invention also relates to an improved valve and seal assembly which includes means for preventing a plug valve from being dislodged and moving inwardly toward the interior of a lumen. 
     BACKGROUND FOR THE INVENTION 
     Dual lumen breast implants for insertion into a human body are well known and have been in use for a number of years. For example, one of my earlier U.S. Pat. No. 6,183,514 defines a self-positioning breast implant. As described, a dual lumen gravity oriented breast prosthesis or implant for surgical implantation includes inner and outer lumens which are defined by inner and outer closed envelopes of a medical grade elastamer. The outer closed envelope or lumen defines a generally oval or tear shape with upper and lower portions. The outer envelope also contains a quantity of fluid material as for example a silicone gel having a first density. The prosthesis also includes a second or inner lumen defined by a second closed envelope of medical grade elastamer which is disposed in and fixed in the lower portion of the outer closed envelope. The inner lumen may be of various shapes such as generally spherical or preferably crescent shape. The second lumen is filled with a saline solution which has a density which is greater than the density of the silicone gel. The inner lumen with its greater density maintains or returns the prosthesis to its predetermined orientation on an individual in whom the prosthesis is implanted when the individual is in a standing or sitting position. 
     A more recent development in mammary prosthesis is disclosed in my more recent Patent on An Adjustable Gel Filled Mammary Prosthesis, U.S. Pat. No. 7,081,136. As disclosed therein, an adjustable gel filled mammary implant includes inner and outer envelopes with the outer envelopment containing about 95% of its volume filled with a silicone gel or the like. The inner envelope is attached to a bottom portion of the outer envelope and defines a volume of about 5% to 10% of the volume of the outer envelope and is filled with saline. The implant also includes a self-sealing valve, filling tube and reservoir for adjusting the size of the implant. 
     For a more natural appearing beast, it is desirable to have the two lumens move independently of each other. This is particularly important in implants having a predominant amount of gel in an outer lumen with a relatively small lumen that can be filled to 10 to 20% (preferably) of the volume of the outer lumen with a saline solution. The small saline inner lumen which is free floating will move naturally within the breast. Further, as the breast is naturally pear shaped, the filled saline chamber will give the implant an anatomical or pear shape to simulate a natural breast. 
     Due to prior difficulties in manufacturing, the smaller inner lumen and outer lumen are adhered together with a single valve allowing saline to be added to the inner lumen. Although functional, the result in shape is not optimal. One and probably the best approach to overcome this problem was to use a filling tube and seal construction in accordance with my earlier U.S. Pat. No. 5,507,808. As described therein an inflatable implant for use in human breast reconstruction includes a chamber which is defined by a flexible membrane. The implant also includes a valve and a flexible filling tube which passes through the valve and into the chamber. 
     The valve comprises a short semi-riged tube that surrounds an opening in the membrane and extends inwardly of the membrane and into the chamber. The semi-riged tube defines a passageway extending therethrough and also defines a relatively small reservoir which opens into the passageway. A filling tube comprises a soft and flexible length of tubing and a solid portion that has an outer diameter which is slightly larger than the inner diameter of the semi-riged tube and is stretchable longitudinally to reduce its outer diameter to facilitate passage through the semi-riged tube and the solid portion is adapted to sealingly engage the semi-riged tube upon relaxation thereof. There are two problems with this approach when making a multi-lumen implant wherein the inner lumen is free floating within the outer lumen. The problems are that the filling tube and sealed construction that includes a small reservoir for a better seal are relatively large and expensive to manufacture. Second, the plug portion of the valve occasionally dislodges and moves backwardly into the inner lumen allowing a leak in the inner lumen. 
     Therefore it is presently believed that there is a need for and potential commercial market for an improved multi-lumen implant with an improved filling tube and seal construction in accordance with the present invention. There should be a market for such implants because the use of a smaller valve allows for a smaller inner lumen as well as a significant reduction in cost. Further, it is presently believed that the new valve and seal will reduce if not eliminate problems of the plug valve becoming dislodged. 
     BRIEF SUMMARY OF THE INVENTION 
     In essence, the present invention contemplates an improved filling tube and seal construction for a multi-lumen breast prosthesis of the type having an outer lumen or chamber and a mass of gel disposed within the outer lumen. The prosthesis also includes an inner lumen or chamber and a mass of saline disposed within the inner lumen. The outer lumen is defined by a flexible membrane with an inlet opening and a first semi-riged tube surrounded by the inlet opening and extending inwardly into the outer chamber. The first semi-riged tube defines a longitudinally extending passageway with a near end adjacent to, abutting and sealed to the inlet opening to close the inlet opening except for the longitudinally extending passageway. The far end of the first semi-riged tube extends into the outer lumen or chamber. 
     A filling tube comprising a soft and flexible length of tubing with a solid portion and a T-shaped flange at its distal end. The solid portion of the filling tube is slightly longer than the length of semi-riged tube while the remaining portion of the filling tube defines a second hollow passageway with an opening for connecting the interior of the filling tube with the interior of the chamber for inflation of the chamber. The filling tube has an outer dimension that is slightly larger than the inner dimension of the semi-riged tube and is stretchable longitudinally to reduce the outer diameter to facilitate passage through the passageway in the semi-riged tube. The solid portion of the filling tube sealingly engages the semi-riged tube upon relaxation thereof but can be stretched longitudinally and moved outwardly through the semi-riged tube by pulling on the proximal portion until the T-shaped flange engages the top of the semi-riged tube. A key element in the present invention resides in means such as a plurality of reverse barbs for preventing a plug valve from being dislodged or moved inwardly into the interior of the inner lumen. These barbs are typically disposed between the solid portions of the filling tube and the semi-riged tube. For example, a plurality of rearwardly directed needle like elements or the like disposed in the solid portion of the filling tube allow the filling tube to move into a constricted area of the semi-riged tube but once pulled into place prevent the remaining plug valve from rearward movement. In effect the solid plug is blocked from movement by the barbs in one direction and by the T-shaped flange in the other direction. 
     In a preferred embodiment of the invention the improved filling tube and seal construction are used for the inner chamber that is filled with saline while a second conventional flap valve is used to close the outer chamber that contains a more viscose silicone gel. This gel is less likely to leak in view of its higher viscosity. Nevertheless, it is contemplated that the improved sealing tube and seal construction may be used for both the interior and outer chambers. 
     The invention will now be described in connection with the accompanying drawings wherein like reference numerals have been used to define like parts. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a single lumen inflatable prosthesis embodying a filling tube and seal construction as shown in  FIGS. 2-6  and shown with a filling tube and an attached injection dome in place for inflating the prosthesis; 
         FIG. 2  is an enlarged view of a portion of  FIG. 1  showing the filling tube in position for inflating the prosthesis; 
         FIG. 3  is an enlarged view of a portion of  FIG. 1  showing a closed filling tube; 
         FIG. 4  is an enlarged view of the filling tube and sealing construction according to one embodiment of the invention; 
         FIG. 5  is a perspective view of a plug seal in accordance with a preferred embodiment of the present invention; 
         FIG. 6  is a cross-section view of a plug seal in accordance with a further embodiment of the invention; 
         FIG. 7  is a schematic cross-sectional view of a breast with a dual lumen mammory prosthesis implanted therein with a dual valve in accordance with one embodiment of the invention; 
         FIG. 8  is a schematic illustration of the dual valve arrangement in an inner and outer lumen wherein the valve is shown as partially closed and a second plug is shown near closure; 
         FIG. 9  is a schematic illustration of a dual lumen implant with inner and outer plug valves in accordance with the invention; 
         FIG. 10  is a schematic illustration of a dual lumen implant with a plug valve, a leaf valve and a filling tube in accordance with the invention; 
         FIG. 11  is schematic illustration of a dual lumen implant as shown in  FIG. 10  but with the filling tube removed; 
         FIG. 12  is a schematic illustration of a dual lumen implant in accordance with a further embodiment of the invention wherein a thin tube connects the inner lumen to the exterior of the outer lumen and wherein a single plug valves acts as a seal for the inner and outer lumen; 
         FIG. 13  is a schematic illustration of the dual lumen implant shown in  FIG. 12  but with the filling tube removed; and 
         FIG. 14  is a schematic illustration of the further embodiment of the invention shown in  FIGS. 12 and 13  within a human breast that illustrates the connection between the inner lumen and the outer lumen and that allows limited movement of the inner lumen while providing for a more natural shape. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     References will now be made in detail to the embodiments of the invention, examples of which are illustrated in the accompanying drawings. A preferred embodiment i.e. best mode of the filling tube and seal construction is shown in  FIGS. 1-3 . In accordance with the invention a filling tube and seal construction is embodied in an inflatable device such as an inflatable implant  13  which includes at least one flexible membrane or lumen  15 . The flexible membrane or lumen  15  defines an inflation chamber  16  which is adapted for filling with a fluid to thereby inflate the implant  13 . The lumen  15  also defines an inlet opening  17  to which an inflating fluid is delivered (See  FIG. 2 ). 
     In accordance with the invention, the filling tube and seal construction includes a semi-rigid tube  18  which has a relatively thick wall with respect to the thickness of the membrane and which surrounds the opening  17 . The semi-riged tube  18  extends inwardly of the lumen  15 , and has a passage  23  therethrough which opens inside of the lumen  15 . 
     The lumen  15  is constructed of a suitable material or membrane such as a medical grade silicone elastomer or similar material which does not react with human tissue, as will be understood by those skilled in the art. And, the short semi-rigid tube  18  may be formed of the same or of a different material but is preferably formed as an integral part of the membrane and derives its semi-rigid characteristic from the thickness of its wall section. It may also be desirable to form a thicker portion  19  of the lumen  15  as illustrated to further support the tube  18 . This thickened portion  19  surrounds the opening  17  and reduces the likelihood of any breaking or tearing of the membrane. The semi-rigid tube  18  also defines an inner passageway or passage  23   
     A filling tube  27  constructed of silicone tubing or the like is adapted to pass through the passage  23  which is defined by the relatively short, semi-rigid tube  18 . The filling tube  27  also includes a solid distal portion  28 , which is preferably slightly longer than the length of the semi-rigid tube  18 , and a proximal portion  29  which defines a hollow passageway  30  and an opening  32 . The opening  32  connects the passageway  30  with the interior of the chamber  16  and operatively connects the interior of the chamber  16  to an injection dome or reservoir  34 . 
     The filling tube  27  is relatively soft so as not to puncture or damage the tube  18  or the lumen  15 . This filling tube  27  has an outer diameter which is slightly larger than the inside diameter of the passageway  23  and is stretchable in the longitudinal direction to reduce its outside diameter. Reduction of the outside diameter facilitates the passage of the filling tube  27  through the semirigid tube  18 . And the solid portion  28  of the filling tube is adapted to sealingly engage the passageway  23  in the semi-rigid tube  18  upon relaxation from a stretched condition. 
     In practice, the filling tube may be forced through the passageway  23  by means of a rigid member (not shown) or could be molded into place by having the lumen and semi-rigid tube molded around the filling tube. In the latter case, the filling tube would include an area of reduced diameter so that the inside diameter of the tube  18  would be smaller than the outside diameter of at least the solid portion  28  of the filling tube  27 . 
     The proximal end  27 ′ of the tube  27  is adapted for connection to a fluid source such as the reservoir  34 . Fluid such as a saline solution is then forced from the reservoir  34  by means of a hypodermic needle inserted therein (not shown) through the passageway  30  and opening  17  and into the chamber  16 . When the chamber  16  is sufficiently filled, the filling tube is stretched longitudinally by pulling and passes through the passageway  23  until the solid distal portion  28  is encompassed by the semi-rigid tube  18 . When the pressure or longitudinal extension is released, the solid distal portion returns to its original outside diameter sealingly engages the semi-rigid tube  18 . 
     In a preferred embodiment of the invention, the solid distal portion  28  includes a generally radially extending flange  35  having a generally T-shaped cross section for engaging a seat  36  on the semi-rigid tube  18 . This radially extending flange acts as a stop means and prevents the filling tube  27  from being pulled through the semi-rigid tube  18  and contributes to the reliability of the seal. 
     Various factors must be considered in constructing the filling tube and seal or valve, such as the thickness of the semi-rigid tube, the stiffness of the materials, the lengths of the semi-rigid tube and the filling tube, their diameters including the nature and/or viscosity of the fluids contained within the implant, of the sealant in the reservoir, the pressure of the fluid, etc. Those skilled in the art will appreciate that the seal must not leak and must not cause discomfort to the patient. 
     It will also be appreciated that inflatable prosthesis of this type often have the filling tube inserted in place at the time the prosthesis is manufactured and prior to packaging. Thus, the filling tube remains in place during the entire shelf life of the prosthesis which can be for a considerable length of time. A number of previous valves acquired a “set” during this time so that when the prosthesis was implanted, expanded, and the filling tube removed, leakage occurred at the valve. This problem was remedied by incorporating a kink or curled valve into the system. However, the complexity of manufacture adds to the cost of the device. Furthermore, the curled valve can often be felt by the patient. It is presently thought that because of the small size of the valve and seal according to the present invention will overcome this tendency and as such constitutes an improvement on the valves disclosed in my earlier patent. 
       FIG. 5  is an enlarged view of a plug valve  34  in accordance with a preferred embodiment of the invention. As shown, the plug valve  34  is formed from the distal end of the solid portion  28  of the filling tube  27  and thus has a generally circular cross-section with the outwardly extending valve  35  at the top of the plug valve  34  to provide a T-shaped cross-section. The plug portion of the plug valve  34  also includes a plurality of rearwardly directed barbs  36 . In other words, the barbs  36  in a preferred embodiment of the invention are pointed rearwardly i.e. toward the interior of a chamber and form an acute angle with a longitudinal axis of a semi-riged tube. With the longitudinal axis of the plug valve with this design, the barbs are pressed down into the soft filling tube as the plug is pulled into the semi-riged tube, but spring upwardly and penetrate into the semi-riged tube if the plug is moved backwards. An alternative plug valve  38  includes a flap-like closure  39  on its end that opens up to prevent the plug valve from being forced out of the semi-riged tube. 
     A dual lumen mammary prosthesis in accordance with a preferred embodiment of the invention is shown in  FIG. 7 . As shown, in  FIG. 7 , a mammary prosthesis or breast implant  40  is implanted in the breast tissue  12  of a patient. The implant  40  includes an outer envelope  44  of a medical elastomer such as silicone and a silicone gel is contained within the outer envelope  44 . The silicone gel  16  may be replaced by other suitable material such as polyvinyl pyrralidone, hyaluronic acid, polyacrlimids and polysacckarides. 
     The walls of the lumen i.e. the outer envelope  44  and inner envelope  48  may be made of various soft flexible biocompatible materials such as silicone elastomer. Preferred materials include silicone elastomers such as polydimethylsiloxane or polymethylvinyl siloxane or copolymers thereof with other substances. Other polymers may be substituted as will be apparent to persons of ordinary skill in the art. 
     As illustrated in  FIG. 7 , the outer envelope  44  has an oval or generally tear-shape with a relatively flat rear portion  45  and rounded dome or forward surface  47 . The outer envelope  44  defines an outer lumen which may be of a generally tear-drop shape or other non-symmetrical shape in order to conform to the contours of a human breast. It should be recognized that in certain cases a round shape may be needed. 
     The implant  40  also includes an inner lumen which is defined by an inner envelope  48 . This inner envelope  48  is preferably of the same medical grade elastomer as the outer envelope  44 . The inner envelope  48  may be of a substantially spherical shape and upon filling is preferably free floating within the outer envelope. The inner lumen or inner envelope  48  also contains a fluid  50  such as silicone solution which has a density greater than the density of the gel in the outer lumen. As illustrated, the implant  40  includes a pair of valves  51  and  52 , one valve  51  for the inner envelope  48  and the other valve  52  for the outer envelope  44 . As shown, the valves  51  and  52  are each plug valves with the valve  51  closing the inner envelope and the plug valve  52  attached to a nylon filament that extends from and positions the valve  52  to be drawn into a semi-riged tube  53 . 
       FIGS. 8 and 9  show the positioning of the two valves  51  and  52  as positioned for adjusting the amount of saline  50  in the inner chamber  48  and before the inner envelope  48  is allowed to float or move freely within the outer chamber and with the fill tube removed through the valve  52 . 
     A further embodiment of the invention is illustrated in  FIGS. 10 and 11  wherein a dual lumen implant includes an inner plug valve  51  in accordance with the present invention for sealing the inner lumen and a leaf valve  53  in the outer lumen.  FIG. 10  illustrates the valves and filling tube in place while  FIG. 11  illustrates the valves  51  and  53  in a closed position with the filling tube removed. 
       FIGS. 12 and 13  illustrate a still further embodiment of the invention wherein an outer envelope and an inner envelope are sealed by a single inner valve  51  and cooperates with a connecting member  68  to thereby maintain the fluid  50  within the inner lumen and at the same time close the chamber  16 . 
     While the invention has been disclosed in connection with its preferred embodiments it should be recognized that changes and modifications may be made therein without departing from the scope of the claims.