Abstract:
A gastric restrictor assembly for positioning within the digestive tract, e.g., stomach, of a patient to treat obesity is disclosed. The gastric restrictor assembly includes an attachment mechanism for attaching the assembly within a body lumen and a valve assembly for adjusting the diameter of a throughbore defined by valve assembly. The gastric restrictor includes first and second actuators which can be actuated transorally for operating the attachment mechanism and the valve assembly.

Description:
BACKGROUND  
       [0001]     1. Technical Field  
         [0002]     The present disclosure relates to a surgical implant for treating obesity in a patient. More particularly, the present disclosure relates to a surgical implant for constricting the stomach of a patient to treat obesity in a patient.  
         [0003]     2. Background of Related Art  
         [0004]     A variety of different approaches are known for the treatment of obesity in a patient. These approaches can be of the non-surgical variety, e.g., dieting, or of the surgical variety, e.g., gastric bypass, small bowel bypass etc. Where non-invasive non-surgical procedures such as dieting rely on the will power of a patient and may not be effective, invasive surgical procedures such as bypass surgery can be risky and have undesirable side effects. As such, less invasive surgical devices for constricting or reducing the capacity of the digestive tract, e.g., the stomach have been developed. These devices include gastric bands which are positioned about the stomach to constrict the stomach and devices such as inflatable balloons for reducing the reservoir capacity of the stomach. Each of these types of devices produce a sense of satiety in a patient to reduce the patient&#39;s desire to ingest food.  
         [0005]     Although the above-identified devices have had some success, improvements to these devices would be desirable.  
       SUMMARY  
       [0006]     In accordance with the present disclosure, a gastric restrictor assembly is provided which includes a housing, a valve assembly and an attachment mechanism. In one embodiment, the valve assembly is supported within the housing and includes a first member, a second member and a plurality of vanes which define a throughbore. The plurality of vanes are pivotally supported about a pivot member on the first member and the first member is fixedly secured within the housing. The second member is rotatably secured to the first member and includes a plurality of cam members. Each of the cam members is positioned within a slot formed in one of the plurality of vanes. The second member is movable in relation to the first member to move the cam members within the slots to effect pivoting of the vanes about the pivot members. The second member is movable between a first position and a second position to move the vanes between a first position defining a minimum throughbore diameter and a second position defining a maximum throughbore diameter.  
         [0007]     In one embodiment, the first member includes a first ring or annular member and the second member includes a second ring or annular member. The second ring member includes gear teeth positioned at least partially about its periphery. An actuator is rotatably supported on the housing and includes gear teeth positioned to mesh with the gear teeth of the second ring member to move the second ring member between its first and second positions.  
         [0008]     In one embodiment, the attachment mechanism includes a plurality of arcuate fastening members or hoops and a drive ring. Each hoop can include a pointed or sharpened tip and an arcuate body having a plurality of threads formed thereon. The drive ring includes an inner surface having a plurality of gear teeth and an outer surface having a helical thread. The fastening members are positioned at least partially within the housing such that each fastening member extends through or is positioned to extend through an opening in the housing. The helical thread of the drive ring is positioned to engage the plurality of the threads on the arcuate body of each fastening member such that upon movement of the drive ring in relation to the fastening member, each fastening member is moved between a retracted position and a deployed or advanced position.  
         [0009]     In one embodiment, the inner surface of the drive ring includes gear teeth which are positioned to mesh with the gear teeth of a drive ring actuator. The drive ring actuator is actuable to effect rotation of the drive ring in relation to the plurality of fastening members.  
         [0010]     In one embodiment, an attachment mechanism actuation tool is provided to actuate the drive ring actuator and a valve assembly adjustment tool is provided to actuate the second member of the valve assembly. Both the attachment mechanism actuation tool and the valve assembly adjustment tool can be configured and dimensioned for transoral actuation of the attachment mechanism and the valve assembly, respectively. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Various embodiments of the presently disclosed gastric restrictor assembly are disclosed herein with reference to the drawings, wherein:  
         [0012]      FIG. 1  is a top perspective view of one embodiment of the presently disclosed gastric restrictor assembly;  
         [0013]      FIG. 2  is a top perspective, exploded view of the valve assembly and attachment mechanism of the gastric restrictor assembly shown in  FIG. 1 ;  
         [0014]      FIG. 3  is a cross-sectional view taken along section lines  3 - 3  of  FIG. 1 ;  
         [0015]      FIG. 4  is a bottom perspective view of the second member of the valve assembly of the gastric restrictor assembly shown in  FIG. 3 ;  
         [0016]      FIG. 5  is a top cross-section view of the gastric restrictor assembly shown in  FIG. 1  illustrating the throughbore of the assembly in its maximum diameter position;  
         [0017]      FIG. 6  is a top cross-sectional view of the gastric restrictor assembly shown in  FIG. 1  illustrating the throughbore of the valve assembly in its minimum diameter position; and  
         [0018]      FIG. 7  is a side view of the gastric restrictor assembly shown in  FIG. 1  attached to an internal wall of the stomach with a portion of the stomach cutaway. 
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0019]     Embodiments of the presently disclosed gastric restrictor assembly and its method of use will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views.  
         [0020]      FIG. 1  illustrates one embodiment of the presently disclosed gastric restrictor assembly shown generally as  10 . Gastric restrictor assembly  10  includes an annular housing  12  which defines a thoughbore  13  and supports a valve assembly  14  and an attachment mechanism  16 . In one embodiment, housing  12  is formed from half-sections  12   a  and  12   b  which are fastened together to enclose valve assembly  14  and attachment mechanism  16 . Actuators  18  and  20  are positioned on a top surface of housing  12  to facilitate operation of valve assembly  14  and attachment mechanism  16 , respectively, as will be described in further detail below.  
         [0021]     Referring to  FIGS. 2-4 , valve assembly  14  includes actuator  18 , a first member  22 , a second member  24  ( FIG. 3 ) and a multiplicity of vanes  26 . First and second members  22  and  24  may be in the form of first and second rings which define a throughbore  28  which is substantially coaxial with throughbore  13  of housing  12 . First member  22  is rotatably fixed to a bottom inner wall of housing  12  such as by pins  30 . A plurality of pivot members  32  are spaced about first member  22 . Each pivot member  32  is positioned and dimensioned to be received in a hole  34  formed in a respective vane  26  such that vanes  26  are pivotally supported on first member  22 . Each vane  26  includes an elongated slot  36 . It is envisioned that pivot members  32  may be formed integrally with housing  12  and first member  22  can be eliminated from assembly  10 .  
         [0022]     Second member  24  is rotatably mounted to first member  22 . In one embodiment, second member  24  includes first and second half-sections  24   a  and  24   b  which are fastened about first member  22 . First member  22  includes an annular recess  40  which is dimensioned to receive an annular rib  42  formed about an inner wall of second member  24  ( FIG. 3 ). Positioning of rib  42  within annular recess  40  of first member  22  rotatably fastens second member  24  to first member  22 .  
         [0023]     Second member  24  includes a plurality of cam members  44  which are positioned on an inner wall of second member  24 . Cam members  44  are received in respective slots  36  of vanes  26 . Slots  36  of vanes  26  are configured such that rotation of second member  24  in relation to first member  22  effects movement of vanes  26  either into or out from throughbore  28 . Vanes  26  define an iris valve for selectively adjusting the diameter or cross-sectional area of throughbore  28 . Although throughbore  28  is illustrated as being circular, other non-circular configurations are envisioned, e.g., rectangular, square, oblong, etc.  
         [0024]     In one embodiment, the outer periphery of second member  24  includes a series of gear teeth  50 . Actuator  18  also includes a series of gear teeth  52 . Gear teeth  52  are positioned to mesh with gear teeth  50  such that rotation of actuator  18  effects rotation of second member  24  in relation to first member  22 . Alternately, gear teeth  50  may only extend over a portion of the outer periphery of second member  24 . As discussed above, rotation of second member  24  in relation to first member  22  effects movement of vanes  26  to selectively vary the diameter or cross-sectional area of thoughbore  28 . It is envisioned that other types of actuators may be employed to operate valve assembly  14 .  
         [0025]     Actuator  18  is rotatably mounted about a post  31  ( FIG. 3 ) formed on housing  12  and includes engagement structure  56  for engaging a valve assembly adjustment tool  57 . Engagement structure  56  may include a hexagonal recess. Alternately, other engagement structure including internal and external interlocking configurations may be used.  
         [0026]     Referring again to  FIGS. 2 and 3 , attachment mechanism  16  includes a drive member or ring  60  and a plurality of fastening elements or hoops  62  ( FIG. 3 ) which are spaced about ring  60 . Ring  60  is rotatably mounted on a circular rail  61  formed on housing  12 . Alternately, ring  60  can be rotatably secured to housing  12  using other known fastening techniques. It is envisioned that fastening elements  62  may comprise configurations other than hoops or, alternately, include a single element having one or more attachment surfaces. In one embodiment, ring  60  includes an inner gear surface  64  and an outer surface defining a helical thread  66 . Each hoop  62  includes a tip  62   a  which may be pointed and a series of teeth or worm gear segments  62   b  positioned to engage helical thread  66  of ring  60 .  
         [0027]     Actuator  20  is rotatably mounted about a post  21  formed on an outer surface of housing  12  and includes gear teeth  68  which are positioned to mesh with gear surface  64  of drive ring  60 . When actuator  20  is rotated within housing  12 , drive ring  60  is also driven in rotation by engagement of gear teeth  68  with gear surface  64 . As drive ring  60  rotates, helical threads  66  engage teeth  62   b  ( FIG. 3 ) of each of hoops  62  to advance tips  62   a  of hoops  62  through openings  12   c  of housing  12  along a substantially arcuate path. As will be discussed in further detail below, hoops  62  function to secure gastric restrictor assembly  10  within a body lumen. An attachment mechanism actuation tool  63 , which can be configured for transoral use, is provided to operate actuator  20 .  
         [0028]     Referring to  FIGS. 1 and 5 - 7 , during installation of gastric restrictor assembly  10  into a body lumen, e.g., the stomach  100 , gastric restrictor assembly  10  is positioned within stomach transorally. Alternately, gastric restrictor assembly  10  can be positioned with a body lumen during an open surgical procedure. The outer wall  90  of housing  12  is positioned adjacent an inner wall of stomach  100 . Next, actuator  20  ( FIG. 1 ) is operated to rotate drive ring  60 . As drive ring  60  is rotated within housing  12 , helical threads  66 , which engage teeth  62   b  of hoops  62 , advances each of hoops  62  from within housing  12  along an arc-shaped path through a portion of inner wall  104  of stomach  100 . The arc-shaped path or curvature of hoops  62  should be such as to advance tips  62   a  of hoops  62  through only a portion of inner wall  104  of stomach  100  without fully penetrating wall  104  of stomach  100 . This will prevent gastric fluids from exiting the stomach into the abdominal cavity. It is envisioned that the shape of hoops  62  may be changed to alter the path of travel of hoops  2  to effect full penetration of a wall of a body lumen if desired. Engagement of hoops  62  with wall  104  of stomach  100  secures gastric restrictor assembly  10  to inner wall  104  of stomach  100 . Although a multiplicity of hoops are illustrated in  FIG. 1 , two or more hoops need only be provided to secure assembly  10  within the stomach.  
         [0029]     When gastric restrictor assembly  10  is secured within the stomach, throughbore  28  of valve assembly  14  defines a passage through the stomach. The diameter of throughbore  28  can be selectively intraorally adjusted from a maximum diameter shown in  FIG. 5  to a minimum diameter shown in  FIG. 6  using valve assembly adjustment tool  57 . As discussed above, adjustment tool  57  ( FIG. 2 ) operates actuation member  18  to reposition vanes  26  of valve assembly  14 .  
         [0030]     It will be understood that various modifications may be made to the embodiments disclosed herein. For example, the actuation mechanism for the valve assembly and/or the attachment mechanism not be gear driven but rather may include other types of drive mechanism, e.g., cam mechanism, etc. Further, the gastric restrictor assembly may be positioned at any position in the digestive tract where restriction may be warranted or desired. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.