Abstract:
A surgical access assembly for receiving instruments of various diameters is disclosed. The access assembly includes a housing defining a longitudinal axis and having a longitudinal opening for passage of a surgical instrument. The access assembly may also include a mechanism disposed within the housing and having a passageway for reception and passage of the surgical instrument in substantial sealed relation therewith. The mechanism may be adapted for reciprocal longitudinal movement within the housing between a first position corresponding to a first dimension of the passageway and a second position corresponding to a second dimension of the passageway. The mechanism may include a single seal element or first and second seal elements. The seal elements may be adapted for lateral movement during longitudinal movement of the seal. The first and second seal elements may be in at least partial overlapping relation when in the first position of the seal. The access assembly may include a lock or latch for preventing movement of the seal elements.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/019,908 filed on Jan. 9, 2008, entitled “ACCESS ASSEMBLY WITH ADJUSTABLE SEAL MEMBER”, the entire contents of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to systems for accessing the body, and more particularly, to trocar systems configured for sealably receiving endoscopic instruments of various diameters. 
     2. Background of Related Art 
     Trocars and other access assemblies are used by surgeons to operate on a patient without having to create large incisions that may become infected and may cause major scaring. Access assemblies are known in the art, as are the instruments inserted therethrough for operating within the body cavity. Typically an access assembly comprises two major components, a sleeve including a housing and a cannula, and an obturator. 
     Accessing the body cavity using an access assembly is a multi-step process. An incision is initially made in the skin using a scalpel or other cutting instrument. Some access assemblies may include a cutting blade or sharpened distal end for performing this function. The obturator, having been inserted into the sleeve of the cannula, is directed through the incision in the skin. By applying pressure against the proximal end of the obturator, the sharpened point of the obturator is forced through the skin until it enters the body cavity. The cannula is inserted through the perforation made by the obturator and the obturator is withdrawn, leaving the trocar cannula as an access way to the body cavity. 
     In order to provide a greater space in which a surgeon may operate and to increase visibility of the tissue being operated on, the body cavity is generally insufflated. To avoid gas leakage from within the cavity prior to or during insertion of an instrument through the cannula, and as instruments are being removed and replace, various seal members have been developed. Conventional access systems generally include one or more seals configured for use with endoscopic instruments of the same or similar diameters. In this manner, all of the instruments inserted through the access assembly must be of substantially similar diameter, otherwise a proper seal will not form between the instrument and the housing. An improper seal may result in leakage of the insufflation gas. 
     However, not all endoscopic instruments have similar diameters. An instrument for performing one procedure may have a different diameter from a second instrument for performing the same procedure, just as instruments for performing various procedures may have different diameters from one another. Successful completion of a procedure may require the use of various instruments throughout the procedure. Thus, completing a procedure using multiple endoscopic instruments may require the use of more than one access assembly each of a different size. 
     Therefore, it would be beneficial to have an access assembly that is configured to receive endoscopic instruments of differing diameters. 
     SUMMARY 
     According to an aspect of the present disclosure, a surgical access assembly is provided. The surgical access assembly includes a housing defining a longitudinal axis and having a longitudinal opening for passage of a surgical instrument, and defining proximal and distal ends. The access assembly further includes a seal disposed within the housing and having a passageway for reception and passage of the surgical instrument in substantial sealed relation therewith. The seal may be adapted for reciprocal longitudinal movement within the housing between a first position corresponding to a first dimension of the passageway and a second position corresponding to a second dimension of the passageway. 
     The first position of the seal may correspond to a proximal position while the second position of the seal corresponds to a distal position. The first dimension of the passageway may be less than the second dimension of the passageway. 
     The seal may include a single seal element or first and second seal elements. The seal elements may be adapted for lateral movement during longitudinal movement of the seal. The seal elements may further be adapted for lateral movement during longitudinal movement of the seal between the first and second positions thereof. The first and second seal elements may be adapted to move laterally outwardly upon movement of the seal from the first position to the second position. The first and second seal elements may be in at least partial overlapping relation when in the first position of the seal. A base may be mounted to each seal element. 
     The surgical access assembly may include a latch for preventing the movement of the first base member. The latch is pivotally mounted across the passageway and is configured to engage the first base member, thereby preventing movement thereof. The latch may include a notch, groove, tab, cam or hook configured to engage the first base member. Rotation of the latch causes disengagement thereof with the first base member, thereby permitting movement of the first and second base members. 
     In an alternate embodiment, the surgical access assembly may further include a lock mounted to the housing for selectively securing the seal at the first position or the second position thereof. The lock may include a lever intersecting the longitudinal opening of the housing and operatively connected to the seal. The lever may be positioned to engage the surgical instrument during passage through the housing to thereby facilitate movement of the seal from the first position to the second position thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing summary, as well as the following detailed description will be better understood when read in conjunction with the appended figures. For the purpose of illustrating the present disclosure, a preferred embodiment is shown. It is understood, however, that the present disclosure is not limited to the precise arrangement and instrumentalities shown. 
         FIG. 1  is a side perspective view of a trocar assembly according an embodiment of the present disclosure; 
         FIG. 2  is a front perspective view of the trocar assembly of  FIG. 1 ; 
         FIG. 3  is a cross-sectional side view of the trocar assembly of  FIGS. 1 and 2 , in a first position; 
         FIG. 4  is a cross-sectional side view of the trocar assembly of  FIGS. 1-3 , in a second position; 
         FIG. 5  is a cross-sectional top view of the trocar assembly of  FIG. 3 , in the first position, taken along line  5 - 5 ; 
         FIG. 6  is a cross-sectional top view of the trocar assembly of  FIG. 4 , in the second position, taken along line  6 - 6 ; 
         FIG. 7  is a cross-sectional side view of the trocar assembly of  FIGS. 1-6 , in the first position; 
         FIG. 8  is a cross-sectional side view of the trocar assembly of  FIGS. 1-7 , in the second position; 
         FIG. 9  is a top view of a first base member of the trocar assembly of  FIGS. 1-8 ; 
         FIG. 10  is an end view of the first base member of  FIG. 9   
         FIG. 11  is a cross-sectional side view of an alternate embodiment of a trocar assembly, in a first position; 
         FIG. 12  is a cross-sectional side view of the trocar assembly of  FIG. 11 , in a second position; 
         FIG. 13  is a cross-sectional top view of the trocar assembly of  FIGS. 11 and 12  in the first position; 
         FIG. 14  is a cross-sectional top view of the trocar assembly of  FIGS. 11-13 , in the second position; 
         FIG. 15  is a cross-sectional side view of the trocar assembly of  FIGS. 11-14 , in the first position; 
         FIG. 16  is a cross-sectional side view of the trocar assembly of  FIGS. 11-15 , in the second position; 
         FIG. 17  is a cross-sectional top view of another embodiment of a trocar assembly, in a first position; and 
         FIG. 18  is a cross-sectional top view of the trocar assembly of  FIG. 17 , in a second position. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein like reference numerals illustrate similar components throughout the several views. As shown in the drawings and as described throughout the following description, as is traditional when referring to relative positioning on an object, the term “proximal” refers to the end of the apparatus which is closer to the user and the term “distal” refers to the end of the apparatus which is further from the user. 
       FIGS. 1-8  illustrate an access assembly  100  in accordance with the principles of the present disclosure. Referring initially to  FIGS. 1 and 2 , access assembly  100  includes a housing  102  and a cannula  104  extending distally therefrom. Access assembly  100  may be configured for use with any known endoscopic or laparoscopic instrument. Cannula  104  is configured to be inserted through the skin into a body cavity with the aid of an obturator (not shown). Cannula  104  may instead include a blade or piercing tip for penetrating through the skin and into a body cavity. Cannula  104  may be integral formed with housing  102 . Alternatively, cannula  104  may be configured for selectable engagement with trocar housing  102 . 
     Cannula  104  forms a substantially tubular member having proximal and distal ends  104   a ,  104   b . Cannula  104  may be composed of plastic, metal, polymers or other suitable material. Cannula  104  may be disposable, or in the alternative, reusable. Cannula  104  may be rigid, or alternatively, cannula  104  may be flexible. Distal end  104   b  of cannula  104  may be open. Distal end  104   b  may instead be configured to include one or more seal members  104 ′ for receiving an instrument therethrough. Cannula  104  may be of any configuration and of any length or diameter. Thus, it is appreciated that the embodiments of the present disclosure are not limited by the configuration of cannula  104  and may be configured for use with any conceivable cannula configuration. 
     Referring now to  FIGS. 3 and 4 , housing  102  of access assembly  100  defines longitudinal axis “k” and has a longitudinal passageway  101  therethrough configured for selectively receiving endoscopic instruments of various diameters. Housing  102  may form a generally rectangular cross-sectional shape, as shown, however, alternate configurations are also envisioned, including but not limited to, circular, square and triangular. Housing  102  defines a first annular portion  103 , a slanted middle portion  105 , and a second annular portion  107 . First annular portion  103  is of a larger diameter than second annular portion  107 , and preferably includes a diameter substantially similar to the diameter of cannula  104 . Slanted middle portion  105  connects first and second annular portions  103 ,  107 . As will be discussed below, slanted middle portion  105  defines substantially T-shaped grooves  105   a  extending between first and second annular portions  105 ,  107 . 
     Still referring to  FIGS. 3 and 4 , housing  102 , includes an adjustable seal mechanism  110 . As will be described below, adjustable seal mechanism  110  is configured-to receive instruments of differing diameters therethrough. Seal mechanism  110  may be configured to establish a substantial sealed relation with the instruments inserted therethrough. Alternatively, seal mechanism  110  may be configured to restrict or limit the movement of an instrument inserted therethrough. In this manner, a seal member ( 203 ′,  104 ′) positioned proximal ( FIG. 11 ) or distal ( FIG. 3 ) of seal mechanism  110  may maintain a seal about the instrument inserted therethrough while seal mechanism  110  may operate to prevent excess movement of the instrument which may compromise the integrity of the seal. 
     Seal mechanism  110  includes a first base member  112  and a second base member  114 . First and second base members  112 ,  114  define substantially planar members configured to be received within passageway  101  of housing  102 . First and second base member  112 ,  114  are adapted to slide in a general longitudinal direction with respect to the longitudinal axis “k” and in a lateral direction. First and second base members  112 ,  114  include seal members  113 ,  115 , respectively, extending therefrom. As will be discussed below, first and second base members  112 ,  114  and corresponding seal members  113 ,  115 , cooperate to receive instruments of different diameters. 
     Turning now to  FIGS. 9 and 10 , because first and second seal members  112 ,  114  are substantial identical, base members  112 ,  114  will be described as relates to first base member  112 . First base member  112  defines a substantially C-shaped member defining an opening including seal member  113  extending therefrom. First base member  112  may be constructed of plastic, metal, polymer or other like material. Seal member  113  may be constructed of rubber, plastic, polymer or other suitable material. Seal member  113  defines a semi-circular opening  116   a  configured to corresponding with a semi-circular opening  118   a  ( FIG. 6 ) defined by seal member  115  extending from second base member  114  for receiving an endoscopic instrument E 1  (FIGS.  3  and  5 )having a first diameter. Seal member  113  defines an increasingly wider opening  116   b  extending from first base member  112 . As will be described below, seal members  113 ,  115  of first and second base members  112 ,  114 , respectively, are configured such that as first base member  112  moves relative to second base member  114 , corresponding openings  116   b ,  118   b  formed in the respective seal members  113 ,  115  adjust in size to accommodate instruments of different diameters. 
     Still referring to  FIGS. 9 and 10 , first base member  112  includes a pair of outwardly extending tabs  112   a . Tabs  112   a  are configured to be received within grooves  105   a  ( FIGS. 3 and 4 ) defined in slanted portion  105  of housing  102  and may slide within groove  105   a . Tabs  112   a  may be substantially T-shaped as shown, or may instead include any other suitable configuration. Tabs  112   a  are configured to permit first base member  112  to slide within grooves  105   a. Preferably, tabs  112   a  and corresponding tabs  114   a  ( FIGS. 5 and 6 ) formed on second base member  114  are configured to maintain first and second base members  112 ,  114  in a horizontal relationship with one another. 
     It is envisioned that base members  112 ,  114  may include any number of tabs. Although grooves  105   a  are shown as only being defined on two opposing sides of housing  102 , it is envisioned that additional grooves may be formed on the other two opposing sides of housing  102 . In this manner, corresponding tabs formed on first and/or second base members  112 ,  114  could be received in the grooves, thereby more securely retaining first and/or second base members  112 ,  114  within housing  102 . In an alternate embodiment, it is envisioned that slanted portion  105  of housing  102  may instead define the elongated tabs or protrusions for being received in a corresponding groove defined by the first and second base members. In this manner, the base members would be slidingly received about the tabs formed in the housing. 
     With particular reference now to  FIG. 10 , first base portion  112  defines slots  112   b  for receiving portions of seal member  115 . Although not shown, second base member  114  includes slots for receiving corresponding portions of seal member  113  ( FIGS. 5 and 6 ). As will be discussed below, as first and second base members  112 ,  114  move toward one another, seal member  115  of second base member  114  is received within slots  112   b  defined by first base member  112 . At the same time, seal member  113  of first base member  112  is received within the slots defined by second base member  112 . 
     It is envisioned that adjustable seal mechanism  110  may include more than two base members appropriately configured for selectively receiving instruments of differing diameters. It is further envisioned that each of the base members may include more than one seal member. By providing more than one seal member per base member the seal members may be overlapped to increase the integrity of the seal. In an alternate embodiment, it is envisioned that the seal mechanism may include single seal member. In this manner, the seal member would stretch radially during longitudinal motion thereof. 
     Referring back to  FIGS. 3 and 4 , adjustable seal mechanism  110  may further include a locking mechanism for preventing the movement of first and second base members  112 ,  114 . One example of a locking mechanism is shown generally as latch  120 . Latch  120  is a substantially L-shaped member including a base  122  and a locking arm  124 . Base  122  pivotally extends into passageway  101  of housing  102 . Locking arm  124  extends distally within housing  102 . Distal end  124   b  of locking arm  124  may include a notch, groove, tab, cam or hook (not shown) for selectively engaging first base member  112  and preventing movement thereof. Distal end  124   b  of locking arm  124  is configured such that when locking arm  124  is rotated distal end  124   b  disengages first base member  112 . Locking arm  124  may be rotated by pivoting base  122  of latch  120  from across passageway  101  prior to insertion of an instrument E 2 . 
     With reference now to  FIGS. 3-6 , in operation access assembly  100  operates to sealingly receive instruments having a range of different diameters. In a first position ( FIGS. 3 and 5 ), adjustable seal mechanism  110  is in a locked position. First and second base members  112 ,  114  are received within grooves  105   a  defined in slanted middle portion  105  of housing  102 . As shown, instrument E 1  may be received within passageway  101  without encountering latch  120 . In this manner, distal end  124   b  of locking arm  124  remains engaged with first base member  112 , thereby preventing movement of first and second base members  112 ,  114 . As discussed above, when seal mechanism  110  is in a first position, a portion of seal member  113  is received within slot  114   b  formed in second base member  114  and a portion of seal member  115  is received within slot  112   b  formed in first base member  112 . Additionally, first and second base members  112 ,  114  may be configured to engage one another to assist in synchronized movement and/or to reduce deflection upon insertion of an instrument therethrough. For example, first and second base members  112 ,  114  may be operationally connected with one another by rail or other mechanical fastener suitable for permitting lateral movement of first and second base members  112 ,  114  relative to one another. In this first position, seal mechanism  110  operates as a conventional seal member, receiving instrument E 1 . 
     Turning now to  FIGS. 4 and 6 , access assembly  100  may be configured in a second position for receiving instrument E 2  having a larger diameter. Prior to insertion of instrument E 2  into passageway  101 , base  122  of latch  120  is pivoted from within passageway  101 . The pivoting of base  122  causes the rotation of locking arm  124 . The rotation of locking arm  124  cause the disengagement of distal end  124   b  thereof from first base member  112 , thereby permitting the movement of first and second base members  112 ,  114  relative to housing  102 . As instrument E 2  engages seal members  113 ,  115 , first and second base members  112 ,  114  translate distally within housing  102 . Distal translation of first and second base members  112 ,  114  causes first and second base member  112 ,  114  to move in an outward or lateral direction with respect to the longitudinal axis. Distal translation of first and second base members  112 ,  114  continues until an opening large enough to sealingly receive instrument E 2  therethrough is achieved. Housing  102  may include a lip or ridge  102   a  ( FIG. 8 ) to prevent excessive deflection of seal members  113 ,  115  when in this second position as instrument E 2  is inserted therethrough. Once instrument E 2  has been inserted through seal members  113 ,  115 , seal mechanism  110  operates as a conventional seal member, sealingly receiving instrument E 2 . 
     Springs  105   b  may be included in grooves  105   a  for biasing first and second base members  112 ,  114  proximally within housing  102 . In this manner, seal members  113 ,  115  are forced closer together, thereby decreasing the opening formed therebetween and increasing the integrity of the seal formed about instrument E 2 . Springs  105   b  also cause the return of first and second base members  112 ,  114  to a first position upon removal of instrument E 2  from within housing  102 . In this manner, access assembly  100  may be reused. 
     In an alternate embodiment, adjustable seal mechanism  110  may be configured to include predetermined stops or recess formed in housing  102  for forming a seal opening of predetermined sizes. In another embodiment, seal mechanism  110  may be externally adjustable using tabs extending through housing  102 . By pushing distally on the tabs extending through housing  102 , a surgeon may be able to set the seal opening prior to insertion of an instrument into housing  102 . Adjustable seal mechanism  110  may also include visual indicators to indicate the degree of opening of seal members  113 ,  115 . The visual indicators may extend through the housing, or the housing may instead include a clear portion for viewing the position of first and/or second base member  112 ,  114 . Housing  102  may include markings corresponding to the size of the opening formed therein. In yet another embodiment, locking mechanism  120  may be configured to permit selective movement of first and second base members  112 ,  114  within housing  102 . 
     Referring now to  FIGS. 11-16 , shown is an alternate embodiment of the present disclosure shown generally as adjustable seal mechanism  210 . Adjustable seal mechanism  210  is substantially similar to seal mechanism  110  and will only be discussed as relates to the differences therebetween. Adjustable seal mechanism  210  includes a locking mechanism  220  for preventing the movement of first and second base members  212 ,  214 . Locking mechanism  120  is maintained with first annular portion  203  of housing  202  and extends within slanted middle portion  205 . Locking mechanism  220  includes a pair of levers  222  extending into passageway  201 . Each of levers  222  are retractably maintained within passageway  201  by a spring or other biasing means (not shown). Levers  222  engage corresponding locking pins  224 . Locking pins  224  are biased proximally within housing  202 . Levers  222  include a notched or cammed surface (not shown) which engage locking pins  224  when levers  222  are in an extended condition, causing locking pins  224  to extend into groove  205   a . Extension of locking pins  224  into grove  205   a  prevents movement of first and second base members  212 ,  214 . 
     Insertion of an instrument into housing  202  large enough to engage levers  222  causes the retraction of levers  222  within housing  202 . Levers  222  are configured such that the retraction thereof causes the retraction of locking pins  224  from within grooves  205   a , thereby permitting the movement of first and second base members  212 ,  214 . Locking mechanism  220  may be configured such that return of levers  222  to the initial, extended position causes the extension of locking pins  224  back into grooves  205   a . In this manner, first and second base members  212 ,  214  may then again be locked into position within housing  202 . 
     Seal mechanism  210  may further include a seal member  203 ′ positioned within first annular portion  203  of housing  202 . Seal member  203 ′ may be configured to receive an instrument E 1  ( FIG. 11 ), E 2  ( FIG. 12 ) therethrough. Seal member  203 ′ may operate in conjunction with seal mechanism  210  to maintain instrument E 1 , E 2  therethrough. In this manner, seal member  203 ′ may operate to form the seal about instrument E 1 , E 2  while seal mechanism  210  prevents excess movement thereof that may compromise the integrity of the seal. 
     Turning now to  FIGS. 17 and 18 , another embodiment of the present disclosure is shown generally seal mechanism  310 . Seal mechanism  310  includes a plurality of base members  312 ,  314 ,  316 ,  318  slideably mounted within housing  302  of trocar assembly  300 . Seal mechanism  310  may include any number of base members. Base members  312 ,  314 ,  316 ,  318  are operably connected to a seal member  315 . Seal member  315  may be composed of rubber, polymer or other suitable material. As will be discussed below, when seal mechanism  310  is in a first position ( FIG. 17 ), seal member  315  defines a first opening  315   a  for receiving an instrument E 1  therethrough. When seal mechanism  310  is in a second position ( FIG. 18 .), seal member  315  is stretched to form a second opening  315   b  for receiving an instrument E 2  having a larger diameter. 
     Base member  312 ,  314 ,  316 ,  318  include spacers  312 ′,  314 ′,  316 ′,  318 ′, respectively, operably positioned therebetween. Spacers  312 ′,  314 ′,  316 ′,  318 ′ are configured to maintain a sealed connection between base members  312 ,  314 ,  316 ,  318  in at least a first position ( FIG. 17 ) and a second position ( FIG. 18 ). Spacers  312 ′,  314 ′,  316 ′,  318 ′ may define an accordion-like configuration, as shown, capable of extending as seal mechanism  310  is moved from the first position to the second position. Alternatively, spacers  312 ′,  314 ′,  316 ′,  318 ′ may define flaps, wedges or other similar structures for maintaining the seal between base members  312 ,  314 ,  316 ,  318  as seal mechanism  310  in at least a first and second position. 
     Referring initially to  FIG. 17 , seal mechanism  310  is shown in a first position. In this first position, seal member  315  of seal mechanism  310  defines an opening  315   a  sized to receive an instrument E 1  ( FIGS. 3 and 11 ) having a first diameter. Spacers  312 ′,  314 ′,  316 ′,  318 ′, operably positioned between base members  312 ,  314 ,  316 ,  318 , respectively, are in a retracted or relaxed condition. In operation, seal mechanism  310  may be moved from the first position to the second position ( FIG. 18 ) as described above with respect to seal mechanisms  110 ,  210 . In a second position, seal member  315  of seal mechanism  310  is stretched or otherwise expanded to define an opening  315   b  sized to receive an instrument E 2  ( FIGS. 4 and 12 ) having a second, larger diameter. 
     It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims append hereto.