Abstract:
A surgical retractor system including: a surgical retractor for retracting tissue surrounding an opening; and an attachment member having a linear or non-linear edge along a length; and an accessory device for use with the surgical retractor, the accessory device having a channel in sliding engagement with the edge along the length, the channel being the other of linear and non-linear along a width thereof such that the accessory device is movable along the length of the edge into a desired position upon the application of a moving force and locked in the desired position in the absence of the moving force. Also provided are various mounts for disposing the edge in the channel and a pseudoelastic arm for supporting the accessory device from the attachment member, the arm being capable of articulation into a desired position yet also maintaining the desired position during a surgical procedure.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to surgical devices, and more particularly, to a suction device for surgical applications in which an organ is supported by the suction device for improved access to the organ.  
           [0003]    2. Prior Art  
           [0004]    Surgical retractors are well known in the art. They are used in surgical procedures to maintain an opening in the skin to provide access to a body cavity and/or organ during surgery. Surgical retractors are often used in combination with accessories, such as suction devices for lifting, rotating, and/or supporting an organ. Such supporting is typically referred to as vacuum stabilization. Such suction devices and surgical retractors are particularly suited for cardiac bypass surgery.  
           [0005]    While the suction devices of the prior art have their advantages, they are typically large in stature and accordingly obstruct a surgeon&#39;s view or access to the surgical field. The vacuum used to support the organ can be aggressive and cause tissue damage and tearing due to high vacuum settings (e.g., 400-700 mm HG). Typically, three-way valves are used for control of the vacuum. Therefore, the surgeon requires an assistant to operate (turn on and off) the valves. Furthermore, it becomes challenging to precisely control the vacuum by turning the valve on and off at a given time. Also, the suction cups of the suction devices are either inflexible or utilize an open-cell foam, both of which serve to cause trauma to the heart muscle and interfere with the heart&#39;s hemodynamic equilibrium. High vacuum pressure tends to push the attached tissue against the rim of the suction cup, which can cause damage to the heart tissue.  
         SUMMARY OF THE INVENTION  
         [0006]    Therefore it is an object of the present invention to provide a suction device for surgical procedures that overcomes the problems associated with the prior art.  
           [0007]    Accordingly, a surgical retractor system is provided. The surgical retractor system comprises: a surgical retractor having: means for retracting tissue surrounding an opening; and an attachment member having at least one edge, the at least one edge being one of linear and non-linear along a length thereof; and an accessory device for use with the surgical retractor, the accessory device having a channel in sliding engagement with the at least one edge along the length, the channel being the other of linear and non-linear along a width thereof such that the accessory device is movable along the length of the at least one edge into a desired position upon the application of a moving force and locked in the desired position in the absence of the moving force.  
           [0008]    Preferably, the attachment member is a side rail and the at least one edge comprises first and second edges, each of which are non-linear along the length. The at least one edge of the attachment member preferably comprises first and second edges, each of which are non-linear along the length and wherein the first and second edges are cantilevered from a base of the accessory device. Preferably, the channel is linear along the width.  
           [0009]    Preferably, the accessory device is a suction device for supporting a tissue surface. The accessory device preferably further has a tab for facilitating the application of the moving force.  
           [0010]    Also provided is an accessory device for use with a surgical retractor. The accessory device comprises: a body having a channel in sliding engagement along a length of at least one edge of the surgical retractor, the at least one edge being one of linear or non-linear along the length, the channel being the other of linear and non-linear along a width thereof such that the accessory device is movable along the length of the at least one edge into a desired position upon the application of a moving force and locked in the desired position in the absence of the moving force.  
           [0011]    The at least one edge is preferably non-linear along the length and the channel is linear along the width. Preferably, the accessory device is a suction device for supporting a tissue surface. The body preferably further has a tab for facilitating the application of the moving force.  
           [0012]    Further provided is a surgical retractor system comprising: a surgical retractor having: means for retracting tissue surrounding an opening; and an attachment member having first and second edges cantilevered from a base; and an accessory device for use with the surgical retractor, the accessory device having: a body having a channel in sliding engagement with the first and second edges; and mounting means for disposing the first and second edges in the channel.  
           [0013]    Preferably, the mounting means comprises an interference between one of the first and second edges of the base and a portion of the body wherein the body is fabricated from a material capable of plastically deforming upon the application of a force to thereby overcome the interference. The mounting means alternatively comprises the body having at least one slotted portion to accommodate a width between the first and second edges different from a channel width. Still another alternative is for the mounting means to comprise the body being fabricated from a deformable material such that a channel width can be varied to accommodate a range of widths between the first and second edges.  
           [0014]    Still further provided is an accessory device for use with a surgical retractor. The accessory device comprising: a working end for interacting with a surgical site during a surgical procedure; a base for mounting to the surgical retractor; and an arm connected at a first end to the base and at a second end to the working end, the arm being fabricated from a pseudoelastic material such that the arm can be articulated into a desired position yet maintain the desired position during the surgical procedure.  
           [0015]    Preferably, the accessory device is a suction device for applying vacuum to a tissue surface, the working end comprises a suction cup connected to a vacuum source, the suction cup having an engagement surface for engaging the tissue surface and wherein the arm maintains the desired position of the suction cup while supporting the tissue surface.  
           [0016]    The pseudoelastic material is preferably type  304  annealed stainless steel. Preferably, the arm is cylindrically shaped and further has at least one undercut formed therein to facilitate its articulation. The accessory device preferably further comprises a pivot joint disposed between the suction cup and the second end of the arm. Preferably, the suction device further comprises a cushion material disposed around at least a portion of the periphery of the arm. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    These and other features, aspects, and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:  
         [0018]    [0018]FIG. 1 illustrates a plan view of a surgical retractor device having a suction device mounted thereon.  
         [0019]    [0019]FIG. 2 illustrates a perspective view of the surgical retractor device of FIG. 1 shown in use for opening the chest wall to provide access to the heart, the suction device shown supporting the heart for improved access thereto.  
         [0020]    [0020]FIG. 3 a  illustrates an isometric view of a preferred implementation of a suction device for use with the surgical retractor device of FIG. 1, only the side rail of the surgical retractor being shown therein for clarity.  
         [0021]    [0021]FIG. 3 b  illustrates a side view of the suction device and side rail of FIG. 3 a.    
         [0022]    [0022]FIG. 4 illustrates a perspective view of a first preferred implementation of a suction cup of the present invention.  
         [0023]    [0023]FIG. 5 illustrates a bottom view for the suction cup of FIG. 4 as seen from view  5 - 5 .  
         [0024]    [0024]FIG. 6 illustrates a sectional view of the suction cup of FIG. 5 as taken along view  6 - 6  of FIG. 5.  
         [0025]    [0025]FIG. 7 illustrates an alternative version of a top portion of the suction cup of FIG. 4, the alternative version having a venting valve integrally formed therein.  
         [0026]    [0026]FIG. 8 a  illustrates a sectional view of the vacuum inlet portion of FIG. 7 as taken along line  8 - 8  of FIG. 7, the vacuum inlet portion being shown with the venting valve in the closed position.  
         [0027]    [0027]FIG. 8 b  illustrates a sectional view of the vacuum inlet portion of FIG. 7 as taken along line  8 - 8  of FIG. 7, the vacuum inlet portion being shown with the venting valve in the open (vented) position.  
         [0028]    [0028]FIG. 9 illustrates an alternative version of the suction cup of FIG. 6, the alternative version having a mesh material inserted in the suction cup portion of the suction cup.  
         [0029]    [0029]FIG. 10 illustrates a perspective view of the mesh material prior to insertion in the suction cup portion.  
         [0030]    [0030]FIG. 11 illustrates a side view of yet another alternative version of the suction cup, the alternative version having a closed cell ring disposed on a lower rim of the suction cup portion of the suction cup.  
         [0031]    [0031]FIG. 12 illustrates a sectional view of the suction cup of FIG. 11 as taken along line  12 - 12  of FIG. 11.  
         [0032]    [0032]FIG. 13 illustrates a plan view of a side rail having a mounting means indicated in phantom lines.  
         [0033]    [0033]FIG. 14 illustrates a sectional view of the side rail and mounting means of FIG. 13 as taken along line  14 - 14  of FIG. 13.  
         [0034]    [0034]FIGS. 15 a  and  15   b  illustrate sectional views of an alternative version of a mounting means, FIG. 15 a  showing the mounting means before being secured to the side rail and FIG. 15 b  showing the mounting means after being secured to the side rail.  
         [0035]    [0035]FIGS. 16 a  and  16   b  illustrate sectional views of an alternative version of a mounting means secured to side rails of varying width.  
         [0036]    [0036]FIGS. 17 a  and  17   b  illustrate sectional views of yet another alternative version of a mounting means, FIGS. 17 a  and  17   b  showing the mounting means secured to side rails of varying width.  
         [0037]    [0037]FIGS. 18 and 19 illustrate sectional views of first and second variations of an arm for use with the suction devices of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0038]    Although this invention is applicable to numerous and various types of organs and surgical procedures, it has been found particularly useful in the environment of surgical procedures on the heart. Therefore, without limiting the applicability of the invention to surgical procedures on the heart, the invention will be described in such environment.  
         [0039]    Referring now to FIGS. 1 and 2, there is illustrated a surgical retractor, generally referred to by reference numeral  100 . The surgical retractor  100  is useful for retracting the skin to expose a body cavity and/or organ (alternatively referred to herein as “tissue”) for performing a surgical procedure thereon. The surgical retractor generally has one or more attachment members for attachment of accessories, such as a suction device. The attachment members are preferably two side rails  102 . The surgical retractor also has at least one transverse rail  104  upon which at least one of the side rails  102  is movable. One and preferably both side rails  102  have means, described fully below for holding accessories useful for the particular surgical procedure being performed. One such accessory is a suction device  106 , which is useful for supporting an organ, such as the heart (shown in FIG. 3) during the surgical procedure to provide improved access to the organ and/or body cavity.  
         [0040]    Referring now to FIGS. 3 a  and  3   b , the suction device  106  typically has a means  107  for movably engaging the side rail, an arm  108 , and a suction cup  110 . The arm  108  is movable, preferably by being bendable, and typically cantilevers the suction cup  110  away from the side rail  102 . The arm  108  is used to position the suction cup  110  over the organ, after which a suction cup portion  112  engages the organ with an applied vacuum to support the organ in a desired position. A ball joint  109  is provided to allow the suction cup portion  112  to rotate freely into any desired position. The arm  108  is further preferably rotatably disposed relative to the suction cup  110 .  
         [0041]    Referring back to FIG. 2, in a typical surgical procedure involving the heart  114 , after the chest wall  116  is opened, the surgical retractor  100  is placed in the opening with the side rail(s)  102  engaging the opening. The side rails  102  are then slid on the transverse rail  104  to expand the size of the opening. The mounting means  107  is positioned on the side rail  102  and locked thereon to position the suction device  106  such that it will not be an obstruction to the surgical procedure. A vacuum is applied to the suction cup portion  112  by a vacuum source (not shown) and tubing  115 . The arm  108  is positioned such that the suction cup portion  112  engages the heart  114  and applies the vacuum to a surface thereof, such as the apical region of the heart. The arm  108  is then raised to partially lift the heart  114  from the chest cavity and support it in the lifted position. In surgical retractors of the prior art, it is required for the arm  108  to be locked in position to support the heart  114 . However, as will be discussed below, the suction device  106  of the present invention does not require the arm  108  to be locked.  
         [0042]    Referring now to FIGS.  4 - 6 , there is shown a preferred implementation of the suction cup  110  of the present invention. Although the suction cup  110  can be of single piece construction, it preferably comprises a suction cup portion  112  and a vacuum inlet portion  118 . The suction cup portion  112  is preferably fabricated from a flexible material such as an elastomer. The elastomer is preferably polypropylene TPE (thermoplastic elastomer). The flexible suction cup portion material, such as c-flex, allows the heart to contract and torque, which allows the heart to maintain its hemodynamic equilibrium.  
         [0043]    The vacuum inlet portion  118  is preferably a rigid or semi-rigid thermoplastic, such as polypropylene. The vacuum inlet portion  118  has a vacuum fitting  120 , such as a hose barb, for connection to the vacuum tubing  115 . The vacuum fitting  120  has a radial bore  122 , which is in fluid communication with an axial bore  124 . The vacuum inlet portion  118  further has a ball  126  at an end thereof. The ball  126  is rotatably disposed in a distal adapter  128  connected to a distal end of the arm  108  to form the pivot joint  109 .  
         [0044]    The suction cup portion  112  is disposed on the vacuum inlet portion  118 . The suction cup portion  112  has a wall  130  which defines a cavity  132  which is in fluid communication with the axial bore  124 . The vacuum inlet portion  118  and suction cup portion  112  can be fixed together in any manner known in the art. Preferably, the vacuum inlet portion  118  is provided with a channel  134  at an end thereof and the suction cup portion  112  is provided with a corresponding lip  136  which mates with and is fixedly retained in the channel  134 .  
         [0045]    Referring now to FIGS. 7, 8 a , and  8   b , there is shown an alternative configuration of the vacuum inlet portion, referred to by reference numeral  118   a  and in which like numerals denote like features. Vacuum inlet portion  118   a  differs from vacuum inlet portion  118  in that it has an integral vacuum valve  138  disposed therein. In the alternatively configured vacuum inlet portion  118   a  illustrated in FIGS. 7, 8 a , and  8   b , the axial bore, referred to by reference numeral  124   a  extends throughout the axial length of the vacuum inlet portion  118   a . The vacuum inlet portion  118   a  further has a vent hole  140  in fluid communication with the axial bore  124   a . A plunger  142  is slidingly disposed in the axial bore  124   a . The plunger  142  has a button  144  on one end thereof for actuating the valve  138  and a seat  146  on another end. A spring  148  is further disposed in the axial bore  124   a  for biasing the plunger  142  in a closed position illustrated in FIG. 8 a  in which the button  144  fully extends from the ball  126  and the seat  126  is seated and sealed against a corresponding surface  150  of the axial bore  124   a . In the closed position, a vacuum applied to the radial bore  122  is in fluid communication with the cavity  132  of the suction cup portion  112  which can be applied to a surface of the tissue or organ to be supported. When the button  144  is depressed, the valve  138  is switched to an open position, as is illustrated in FIG. 8 b . In the open position, the seat  146  is no longer seated against the corresponding surface  150  of the axial bore  124   a  and the vent hole  140  vents the vacuum applied to the axial bore  124   a  and cavity  132  to thereby turn the vacuum applied to the tissue or organ off.  
         [0046]    Those skilled in the art will appreciate that the valve  138  allows a surgeon to control the applied vacuum independently with his thumb or fingertips and further allows the surgeon to place the suction cup portion  112  at the region where he/she desires and to turn the applied vacuum on or off at will without the need for an assistant. The vacuum valve  138  can be placed at the suction device itself with a button  144  control, as shown, or in another convenient area which permits the surgeon to easily operate the valve without the need for an assistant.  
         [0047]    Referring back to FIGS. 5 and 6, there is shown a preferred implementation of the suction cup portion  112  of the suction cup  110 . The wall  130  of the suction cup portion  112  preferably has a plurality of ribs  152  for adding flexibility to a neck portion  154  of the suction cup portion  112 . The suction cup portion  112  further has a cupped portion  156  which flares outwardly from a central axis A from the neck portion  154  towards a lower rim  158 . The lower rim  158  inverts towards the central axis A and defines an opening  159  into the cavity  132 . The lower rim  158  further provides a sealing surface that engages against the organ/tissue.  
         [0048]    An inner surface  160  of the cupped portion  156  preferably has a plurality of channels  162   a ,  162   b  formed thereon. The channels  162   a ,  162   b  are more preferably formed in both a circumferential and axial direction, the circumferential channels being referred to by reference numeral  162   a  and the axial channels being referred to by reference numeral  162   b . Both the circumferential and axial channels  162   a ,  162   b  are formed at predetermined spacings along the inner surface  160  of the wall  130 . Preferably, the axial channels  162  are interconnected at a common point, such as recessed portion  163 . The circumferential and axial channels  162   a ,  162   b  allow the vacuum to be distributed evenly over the cupped cardiac region and also prevent the possibility of a vacuum line blockage.  
         [0049]    Referring now to FIG. 9, there is shown an alternative implementation of the suction cup portion  112  of the suction cup device  110  of the present invention. In the alternative implementation illustrated in FIG. 9, an elastic mesh  164  is disposed in the cavity  132  proximate the lower rim  158 . The elastic mesh  164  material is preferably Merselene or Prolene or other elastic type material. Prolene and Merselene fiber mesh are non-absorbable knitted products that are flexible and compliant yet afford excellent strength, durability, and surgical adaptability. The elastic mesh  164  can be disposed on the suction cup or attached thereto, such as by bonding, heat staking, or by an o-ring support. If bonded, a bonding material such as lactite is preferably used to attach the elastic mesh  164  directly on the inner surface  160 . If heat staked, the suction cup portion  112  material is melted onto a surface of the elastic mesh  164 . Of course, in such a bond, the melting point for the suction cup portion  112  material is lower then the melting point for the elastic mesh  164  material. If supported with an o-ring (not shown), the o-ring of an elastic material is overmolded on the circumferential edge of the elastic mesh  164  and the mesh/o-ring combination is inserted into the cavity  132  without bonding, preferably at the junction between the wall  130  and the lower rim  158 . The o-ring (not shown) retains the elastic mesh  164  in the cavity  132  and behind the lower rim  158  and also allows for added flexibility of the mesh.  
         [0050]    [0050]FIG. 10 illustrates the elastic mesh  164  prior to insertion in the cavity  132  of the suction cup portion  112 . As shown in FIG. 9, the elastic mesh  164  is preferably inserted having a convex shape which engages the tissue or organ that is being supported. To facilitate the manipulation of the elastic mesh  164  into the convex shape, the elastic mesh  164  preferably has a plurality of triangular cut-outs  166  formed at equal spacings along its circumference. Those skilled in the art will appreciate that the elastic mesh  164  supports the tissue or organ as the suction retains the tissue or organ in position. The elastic mesh  164  also prevents tissue damage and minimizes the possibility of vacuum line clogging.  
         [0051]    Referring now to FIGS. 11 and 12, there is shown another alternative embodiment of the suction cup portion  112  of the suction cup  110  of the present invention. In the alternative version illustrated in FIGS. 11 and 12, a closed-cell foam  168  is disposed on the lower rim  158  to engage the organ or tissue to be supported. The closed cell foam  168  is preferably cylindrical and having an opening  170  corresponding with the opening  159  formed by the lower rim  158 . The closed cell foam  168  is preferably a hydrophobic closed cell foam, such as polyethylene Ethyl vinyl acetate. The close cell foam  168  can be attached to the lower rim  158  by any means known in the art, such as by adhering with an epoxy, a solvent weld, or heat weld.  
         [0052]    In a pig study, the hydrophobic close cell foam  168  on the lower rim  158  showed the best tissue/organ attachment compared to hydrophilic close cell foam, rubber, and silicone. In addition, the hydrophobic close cell foam  168  induced the least amount of tissue injury (ecchymosis) and conformed best to cardiac apical and lateral regions. The pig study also showed that the compliant characteristic of the close cell foam  168  was critical in conformability. Thus, the hydrophobic closed cell foam  168  on the lower rim  158  allows cardiac contraction while maintaining vacuum seal, secured attachment while minimizing tissue injury, and conforms to the apical and lateral attachment positions of the heart.  
         [0053]    Although discussed separately, the circumferential and radial channels  162   a ,  162   b , the elastic mesh  164 , and the closed cell foam  168  can be used in any combination in the suction cup  112 , including all such features.  
         [0054]    Referring now to FIGS. 13 and 14, there is shown a preferred mounting means  107  for slidable attachment to the side rail  102 . The mounting means  107  is shown in phantom lines in FIG. 13 to clearly show its relationship with the side rail  102 . In addition to being slidable along the side rail  102  into a desired position, the mounting means  107  must also lock into the desired position to prevent further movement of the suction device  106  during the surgical procedure being performed. The suction device  106  can have any one of the typical mounting means known in the art, such as the screw down mount  107  shown in FIG. 2. The screw down mount  107  typically has a knob  172 , a base  174 , and a key (not shown). The knob  172  threadingly engages the key through the base  174  such that when the knob  172  is tightened, the key urges against a slot (not shown) on the underside of the side rail  102  to lock the suction device  106  in the desired position.  
         [0055]    Referring back to FIGS. 13 and 14, a preferred mounting means  107  is shown. As illustrated in FIG. 13, the side rail  102  has at least one edge  176  (referred to hereinafter as a “first edge”), which is non-linear. Preferably, the side rail has a second edge  178  that mimics the curve of the first edge  176 . The non-linearity of the first and second edges  176 ,  178  can be a simple radius (r) as is illustrated in FIG. 13, or it can be have a plurality of curved and/or straight segments. The first and second edges  176 ,  178  preferably are cantilevered from a base  180  of the side rail  102  to form a “t” cross-section. The mounting means  107  preferably has a body  182  having a channel  184  substantially corresponding to the “t” cross-section of the side rail  102 . The channel  184  has a linear width (w) such that it can be wiggled (applying a back and forth motion along direction +/− A while maintaining a force (F) in the +A direction to move the body  182  in the +A direction) along the curved edges  176 ,  178  into a desired position and will stay locked in the desired position absent further wiggling of the body  182 . To facilitate the wiggling of the body  182 , a tab  186  is provided which protrudes from the body  182 , preferably in a direction away from the opening in the body so as not to obstruct a surgeon&#39;s view or access into the body.  
         [0056]    While the side rail  102  is shown by way of example as having non-linear edges  176 ,  178  and the body  182  of the mounting means  107  is shown having a linear channel  184  width, those skilled in the art will appreciate that an opposite configuration will function in the same manner. That is, a side rail  102  having straight edges (not shown) and a mounting means  107  having a body with a curved channel (not shown) will operate similarly to the configuration described above in that the mounting means  107  can be wiggled into a desired position and would remain in the desired position absent further wiggling. Furthermore, while the side rail  102  is described by way of example as having cantilevered edges  176 ,  178 , and the body  182  of the mounting means  107  is described as having a corresponding channel  184 , those skilled in the art will also appreciate that the body  182  of the mounting means  107  can have cantilevered edges (not shown) and the side rail  102  can have a corresponding channel (not shown). Such an alterative configuration would also have the same intended function as the configurations described above in that the body  182  can be wiggled into a desired position and remain there absent further wiggling. Those skilled in the art will appreciate that the preferred mounting means  107 , in any of the configurations discussed above, provides several advantages over the screw down type of mounting means of the prior art. For example, the mounting means  107  described above is less complicated and more economical since it has no moving parts. Furthermore, the preferred mounting means  107  described above requires a single hand for manipulation thereof, thus, eliminating the need for an assistant for placement and locking of the suction device  106  into a desired position.  
         [0057]    Referring now to FIGS. 15 a ,  15   b ,  16   a ,  16   b ,  17   a , and  17   b , there are shown cross-sectional views of three variations of a mounting means  107 . Each of the mounting means  107  has a body  182  having a channel  184  formed therein. The channel  184  may have a straight or curved width and may be utilized with the preferred mounting means as discussed above with regard to FIGS. 13 and 14, or the channel  184  may be used with other mounting means known in the art, such as a screw down type. Each of the channels  184  depicted in the mounting means  107  of FIGS. 15 a ,  15   b ,  16   a ,  16   b ,  17   a , and  17   b , engage a side rail  102  having a base  180  with cantilevered edges  176 ,  178 .  
         [0058]    Referring specifically to FIGS. 15 a  and  15   b , a first variation of the mounting means  107  is shown in which a force F is required in the direction of arrow F to secure the mounting means  107  on the side rail  102 . FIG. 15 a  shows a slight interference between a portion  188  of the body  182  of the mounting means  107  and one of the edges (shown as the second edge  178 ) of the base  180  of the side rail  102 . Such interference exists when the other of the edges (shown as the first edge  176 ) is placed in a corresponding portion of the channel  184  and the interference portion  188  rests on the other edge  178 . A downward force F is applied to the body  182  in the vicinity of the interference portion  188  to force the second edge  178  into a corresponding portion of the channel  184  as shown in FIG. 15 b . This type of fit between mating parts is commonly referred to as a “snap” fit. To facilitate the snap fit between the body  182  of the mounting means  107  and the base  180  of the side rail  102 , at least a portion of the body  182  is preferably fabricated from a material having enough elasticity to plastically deform under the applied force F. Preferably, at least the body  182  of the mounting means  107  corresponding to the channel  184  is made from a thermoplastic, such as polypropylene.  
         [0059]    Referring now specifically to FIGS. 16 a  and  16   b , there is shown a second variation of the mounting means  107 . In the second variation, the body  182  of the mounting means  107  has a channel  184  with at least one extra slotted portion  190  for accommodating side rails  102  of varying widths w1, w2. FIG. 16 a  shows a side rail  102   a  having a first width w1 between the first and second edges  176 ,  178 . The body  182  of the mounting means  107  is shown secured on the base  180  of the side rail  102   a  such that the first and second edges  176 ,  178  are disposed in the channel  184  and the mounting means  107  is substantially coplanar with the side rail  102   a . FIG. 16 b  shows a side rail  102   b  having a second width w2, greater than the first width w1. However, the same mounting means  107  can accommodate either of the side rails  102   a ,  102   b . As shown in FIG. 16 b , one of the edges (shown as the first edge  176 ) is disposed in a corresponding portion of the channel  184  as discussed above. However, the other of the edges (shown as the second edge  178 ) is disposed in the extra slotted portion  190 . Although in this configuration, the body  182  of the mounting means  107  is slightly inclined with respect to the side rail  102   b , the operation of the suction device  106  is not altered due to the articulation of the arm  108  and the pivoting of the suction cup  110  relative to the arm  108  provided by the pivot  109 .  
         [0060]    Referring now specifically to FIGS. 17 a  and  17   b , there is shown a third version of the mounting means  107 , which like the second version shown in FIGS. 16 a  and  16   b , can accommodate side rails  102  of different widths w1, w2. FIG. 17 a  shows the body  182  of the mounting means  107  secured on the side rail  102   a . Specifically, the first and second edges  176 ,  178  are disposed in corresponding portions of the channel  184 . The body  182  of the mounting means, or at least the portion of the body  182  corresponding to the channel  184  is fabricated from a stretchable material, such as an elastomer, such that it can be stretched in the direction of arrow B. A preferred elastomer is polypropylene. FIG. 17 a  shows the body  182  in a relaxed (unstretched) state secured on a side rail  102   a  having a width w1 between the first and second edges  176 ,  178 . FIG. 17 b  shows the same body  182  stretched in direction B by the application of a force F to fit over a side rail  102   b  having a width w2, greater than width w1. Those skilled in the art will appreciate that unlike the second version shown in FIGS. 16 a  and  16   b , the third version of the mounting means  107  can accommodate side rails  102  having a range of widths.  
         [0061]    Referring now to FIGS. 18 and 19, there is illustrated the arm  108  of the suction device  106 . The arm  108  is shown in FIGS. 18 and 19 apart from its mating portions of the suction device  106 . A first end of the arm  192  is fixed in the mounting means, preferably, by a force fit, braze, or other means known in the art. A second end  194  of the arm  194  is disposed in the distal adaptor  128 , preferably in a rotating fashion. The arm  108  is preferably of a unitary construction having a central undercut portion  196 , or alternatively, a series of undercut portions  198  as shown in FIG. 19. The arm  108  is fabricated from a malleable material which can be deformed into a desired shape yet still be resilient enough to remain in such deformed position to support an organ or tissue cantilevered at the suction cup  110 . Preferably, the malleable material is a type  304  annealed stainless steel.  
         [0062]    The arm  108  can be used in either a straight configuration, as shown in FIGS. 3 a  and  3   b , or in a curved configuration, as shown in FIGS. 1 and 2. A cushion material  200  is preferably disposed around all portions of the arm  108  except the first and second ends  192 ,  194 . The cushion material  200  can be prefabricated and applied on the arm  108  or molded directly onto the arm  108 . The cushion material can be any flexible material, such as c-flex, which aids in the resiliency of the arm. Those skilled in the art will appreciate that the arm  108  of the present invention has many advantages over the arms of the prior art, including, simplicity of design (contains no moving parts), ease of operation (does not have to be actuated into and out of a locked position), and low profile (does not encumber the surgeons view or access to the surgical site.  
         [0063]    While there has been shown and described what are considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.