Abstract:
A cannula assembly includes a cannula and an obturator. The cannula includes an elongated shaft dimensioned to access tissue. The elongated shaft has a lumen extending therethrough. The elongated shaft includes a first shaft segment having a first pre-determined configuration and a second shaft segment having a second pre-determined configuration different from the first pre-determined configuration. The obturator includes an elongated body adapted for insertion through the lumen of the elongated shaft. The elongated body includes a first body segment having a configuration in general accordance with the first pre-determined configuration of the first shaft segment and a second body segment selectively adaptable to conform to the second pre-determined configuration of the second shaft segment upon insertion through the lumen of the elongated shaft.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/768,568, filed Feb. 25, 2013, the entire disclosure of which is incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to surgical instruments and, more particularly, to access assemblies for providing access to internal body cavities, tissues and organs. 
     2. Background of Related Art 
     Laparoscopic surgical procedures are minimally invasive procedures in which operations are carried out within the body by means of elongated instruments inserted through small incisions in the body. Laparoscopic procedures are desirable in that they improve patient recovery time and minimize hospital stays as compared to open surgical procedures. Laparoscopic procedures also leave minimal scarring (both internally and externally) and reduce patient discomfort during the recovery period. 
     During a typical laparoscopic, or minimally invasive procedure, surgical objects, such as surgical access devices, e.g., trocar and cannula assemblies, or endoscopes, are inserted into the patient&#39;s body through the incision in tissue. In general, prior to the introduction of the surgical object into the patient&#39;s body, insufflation gasses are used to enlarge the area surrounding the target surgical site to create a larger, more accessible work area. Accordingly, the maintenance of a substantially fluid-tight seal is desirable so as to prevent the escape of the insufflation gases and the deflation or collapse of the enlarged surgical site. 
     Due to the relatively small interior dimensions of the cannulas and/or access ports used in laparoscopic procedures, only elongated, small diametered instrumentation may be used to access the internal body cavities and organs. The manipulation of such instruments within the internal body is similarly limited by both spatial constraints and the need to maintain the body cavity in an insufflated state. 
     SUMMARY 
     In accordance with the present disclosure, a cannula assembly is provided. The cannula assembly includes a cannula and an obturator. The cannula includes an elongated shaft dimensioned to access tissue. The elongated shaft has a lumen extending therethrough, defines a longitudinal axis and has proximal and distal ends. The elongated shaft further includes a first shaft segment having a first pre-determined configuration and a second shaft segment having a second pre-determined configuration that is different from the first pre-determined configuration. The obturator includes an elongated body adapted for insertion through the lumen of the elongated shaft. The elongated body has proximal and distal ends. The elongated body further includes a first body segment having a configuration in general accordance with the first pre-determined configuration of the first shaft segment and a second body segment selectively adaptable to conform to the second pre-determined configuration of the second shaft segment upon insertion through the lumen of the elongated shaft. 
     In one embodiment, the first pre-determined configuration of the first shaft segment defines a general linear segment and the first body segment of the elongated body defines a generally corresponding linear segment. 
     In another embodiment, the second pre-determined configuration of the second shaft segment defines a general arcuate segment. Upon insertion of the elongated body through the lumen of the elongated shaft, the second body portion of the elongated body is positioned in the second pre-determined configuration having a generally corresponding arcuate segment. 
     In yet another embodiment, the second shaft segment of the elongated shaft is disposed adjacent the distal end of the elongated shaft. Alternatively, the second shaft segment of the elongated shaft may be disposed intermediate the proximal and distal ends of the elongated shaft. 
     In still another embodiment, the distal end of the elongated body defines a conical-shaped configuration to facilitate advancement through tissue. 
     In still yet another embodiment, the elongated body of the obturator defines a longitudinal axis. The second body segment of the elongated body is initially positioned in general alignment with the longitudinal axis. However, upon insertion of the elongated body through the lumen of the elongated shaft, the second body segment is positioned in general oblique relation with the longitudinal axis in general accordance with the second pre-determined configuration of the second shaft segment. 
     A surgical access system is also provided in accordance with the present disclosure. The surgical access system includes an anchor member and a cannula assembly. The anchor member is positionable within a passage in tissue. The anchor member includes a compressible material and defines a proximal end, a distal end and an intermediate portion. The anchor member is adapted to transition between an at least partially compressed condition to facilitate introduction within the passage in tissue and an at least partially expanded condition to substantially anchor the anchor member relative to the tissue. The anchor member further includes one or more ports extending therethrough. The cannula assembly includes a cannula defining a longitudinal axis and a lumen extending therethrough. The cannula includes a cannula segment offset with respect to the longitudinal axis. 
     The access system may include an obturator having an elongated obturator body adapted for insertion through the lumen of the cannula. The obturator body has a flexible body segment adapted to follow the path defined by the offset cannula segment. The elongated body has an end dimensioned to extend beyond the cannula and configured to facilitate advancement of the obturator and cannula through the one or more ports of the anchor member with the internal surfaces defining the at least one port of the anchor member establishing a substantial seal about the cannula. 
     In embodiments, the cannula assembly may be configured according to any of the embodiments of the cannula assembly discussed above. 
     In another embodiment, a surgical instrument having a flexible shaft segment and an end effector adapted to perform a surgical task is dimensioned for advancement through the lumen of the cannula in the absence of the obturator whereby the flexible shaft segment follows the path defined by the offset cannula segment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the subject instrument are described herein with reference to the drawings wherein: 
         FIG. 1  is a side, cross-sectional view of one embodiment of a pre-bent access instrument in accordance with the present disclosure; 
         FIG. 2  is a side plan view of a partially-bendable obturator for use with the pre-bent access instrument of  FIG. 1 ; 
         FIG. 3  is a side, cross-sectional view showing the obturator of  FIG. 2  inserted through the pre-bent access instrument of  FIG. 1 ; 
         FIG. 4A  is an exploded, perspective view of another embodiment of a pre-bent access instrument in accordance with the present disclosure; 
         FIG. 4B  is a perspective view of the pre-bent access instrument of  FIG. 4A  illustrating an obturator inserted therethrough; 
         FIG. 5  is a side view of a compressible port anchor in accordance with the present disclosure configured for insertion into an incision in tissue; 
         FIG. 6  is a side view of the compressible port anchor of  FIG. 5  shown inserted through the incision in tissue and having a pre-bent access instrument inserted through a port thereof; and 
         FIG. 7  is a side view of the compressible port anchor of  FIG. 5  shown inserted through the incision in tissue with a pre-bent access instrument inserted through a port thereof and a flexible surgical grasper inserted through the pre-bent access instrument. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the presently disclosed surgical instruments will now be described in detail with reference to the drawing figures wherein like reference numerals identify similar or identical structural elements. As shown in the drawings and described throughout the following description, as is traditional when referring to relative positioning on a surgical instrument, the term “proximal” or “trailing” refers to the end of the apparatus which is closer to the user and the term “distal” or “leading” refers to the end of the apparatus which is further away from the user. 
     Turning now to  FIG. 1 , a surgical instrument according to the present disclosure is shown generally indentified by reference numeral  10 . Access instrument  10  includes an elongated shaft  12  having a proximal end  14 , a distal end  16  and defining a lumen, or passageway  20  therethrough. Access instrument  10  may be configured as an access portal, e.g., a trocar or a cannula, for providing access to internal body cavities and organs. More specifically, surgical instruments, fluids and/or medicaments may be inserted through lumen  20  of access instrument  10  for use at an internal surgical site. Further, a seal member  30  may be disposed at proximal end  14  of shaft  12  for sealingly engaging an instrument (or instruments), e.g., an obturator  50  (see  FIG. 2 ), inserted through lumen  20 . 
     Elongated shaft  12  of access instrument  10  includes a linear portion  17  and an arcuate, or curved portion  18 . Linear portion  17  is disposed about longitudinal axis “X,” while curved portion  18  bends, curves off, or is obliquely arranged with respect to longitudinal axis “X.” Although a specific configuration of curved portion  18  is shown in  FIG. 1 , it is envisioned that curved portion  18  may define various curved, angled, or other bent configurations. Elongated shaft  12  may be formed from any suitable rigid, or semi-rigid medical grade material, e.g., stainless steel, or other suitable bio-compatible materials, e.g., polymeric materials. It is also envisioned that elongated shaft  12  may be formed at least partially from a shape memory material which undergoes a shape-transformation when subject to body temperatures, thereby shaping the surgical instrument, e.g., access instrument  10 , to a desired pre-bent, or curved configuration. 
     An obturator  50  for use with access instrument  10  is shown in  FIG. 2 . Obturator  50  includes a shaft  52  having a proximal end  54  and a distal end  56  and is configured for insertion through lumen  20  of access instrument  10 . A hub  55  is disposed at proximal end  54  of shaft  52 , while distal end  56  of shaft  52  includes a pointed distal tip  57 . 
     Shaft  52  of obturator  50  includes a relatively rigid portion  58  and a less-rigid, or flexible portion  59 . Rigid portion  58  of shaft  52  may be formed from any suitable medical grade material, e.g., stainless steel, or other suitable rigid bio-compatible material, e.g., polymeric materials. As shown in  FIG. 2 , flexible portion  59  of shaft  52  may be formed from a spring coil  60  or, alternatively, flexible portion  59  of shaft  52  may be formed from bio-compatible flexible tubing (not shown) or any other suitable resiliently flexible material. Further, flexible portion  59  may define a length that is equal to, or greater than a length of curved portion  18  of access instrument  10 , such that as, shown in  FIG. 3 , obturator  50  is positionable within lumen  20  of access instrument  10  to conform to the configuration, or shape of access instrument  10 . 
     With continued reference to  FIG. 2 , rigid portion  58  of shaft  52  is coaxially disposed about longitudinal axis “X,” and provides structural support to shaft  52 , while flexible portion  59  is capable of being bent or angulated relative to the longitudinal axis “X” of shaft  52  in any radial direction to conform obturator  50  to a desired configuration, e.g., the pre-bent configuration of shaft  12  of cannula or access instrument  10 . However, although flexible portion  59  is radially deflectable, it is envisioned that flexible portion  59  of shaft  52  may be substantially rigid, in the axial direction. 
       FIG. 3  illustrates obturator  50  inserted through and positioned within lumen  20  of access instrument  10 . As shown, pointed distal tip  57  of obturator  50  extends distally from distal end  16  of access instrument  10 , while hub  55  of obturator  50  extends proximally from proximal end  14  of access instrument  10 . More particularly, pointed distal tip  57  allows for penetration, or dissection through tissue. Flexible portion  59  of obturator  50  is deflected off axis or angulated relative to longitudinal axis “X” to conform to the curved configuration of curved portion  18  of shaft  12  of access instrument  10 . However, due to the axial stiffness, or rigidity of flexible portion  59  of shaft  52 , the shaft  52  is not compressed upon distal advancement of access instrument and obturator  10  and  50 , respectively, through tissue. Accordingly, with obturator  50  positioned within access instrument  10 , the access assembly may be advanced distally, lead by pointed distal tip  57  of obturator  50 , through tissue to an internal surgical site. Obturator  50  may then be removed from access instrument  10  such that lumen  20  provides an access port, or cannula, for performing a minimally-invasive surgical procedure at the internal surgical site. 
     Turning now to  FIG. 4A , in one embodiment, trocar, or access instrument  100  includes respective proximal and distal ends  102 ,  104 , a shaft or elongate member  106  disposed therebetween and seal housing  108 . Access instrument  100  is similar to access instrument  10  discussed above. 
     Elongate member  106  of access instrument  100  includes a straight, or linear portion  107   a  and a curved, or bent portion  107   b  extending along at least a portion of the length thereof. Elongate member  106  further defines an opening  110  extending longitudinally therethrough that is dimensioned to permit the passage of surgical instrumentation therethrough, such as obturator  500  ( FIG. 4B ). As in the previous embodiment, obturator  500  includes a flexible portion  509  ( FIG. 4B ) configured to conform to curved portion  107   b  of access instrument  100  when inserted therethrough and a rigid portion  508  to provide structural support to obturator  500 . Obturator  500  is similar to obturator  50  ( FIG. 2 ). 
     Access instrument  100  includes seal housing  108  which is associated with or mounted to housing  103  of the access instrument  100 . Seal housing  108  includes an instrument seal  112  that is adapted to receive surgical instrumentation inserted into longitudinal opening  110  so as to form a substantially fluid-tight seal therewith. Access instrument  100  may further includes a closure valve  114  within seal housing  108  or cannula housing  103  that is biased toward a closed position, but is adapted to open upon the introduction of the surgical instrumentation inserted into longitudinal opening  110  to allow the surgical instrumentation to pass therethrough. In the closed position, i.e., in the absence of surgical instrumentation, closure valve  114  creates a fluid-tight seal to, for example, inhibit insufflation gas for escaping through longitudinal opening  110  of access instrument  100 . 
     Turning now to  FIG. 4B , access instrument  100  is shown with obturator  500  inserted therethrough. More specifically, pointed distal tip  507  of obturator  500  extends distally from distal end  104  of access instrument  100 , while hub  505  of obturator  500  extends proximally from proximal end  102  of access instrument  100 . Further, flexible portion  507  of obturator  500  is bent, or conformed to pre-bent curved portion  107   b  of access instrument  100 . From this position shown in  FIG. 4B , the access assembly may be inserted through tissue or, as will be described below, may be inserted through an access portal, e.g., access portal  1000  ( FIG. 5 ). 
     With reference now to  FIGS. 5-6 , a seal anchor member  1000  for use during a minimally-invasive surgical procedure is shown. Seal anchor member  1000  defines a longitudinal axis “X” and has a proximal end  1020 , a distal end  1040 , and an intermediate portion  1060  that is disposed between the proximal and distal ends  1020 ,  1040 , respectively. Seal anchor member  1000  further includes one or more ports  1080  that extend longitudinally therethrough between proximal and distal ends  1020 ,  1040 , respectively, thereof. 
     Seal anchor member  1000  may be formed from a suitable foam material, e.g., a polyisoprene foam, having sufficient compliance to form a seal about one or more surgical instruments, e.g., access instrument  100 , inserted through one of ports  1080  and also to establish a sealing relation with surrounding tissue. It is envisioned that seal anchor member  1000  be sufficiently compliant to accommodate off axis motion of surgical instrumentation, e.g., access instrument  100 , inserted therethrough. Seal anchor  1000  may be the port anchor disclosed in commonly assigned U.S. patent application Ser. No. 12/244,024, filed Oct. 2, 2008, the entire contents of such disclosure being incorporated herein. 
     As shown in  FIGS. 5-6 , proximal and distal ends  1020 ,  1040  of seal anchor member  1000  define substantially planar surfaces, although it is envisioned that either or both of proximal and distal ends  1020 ,  1040 , respectively, of seal anchor member  1000  may define surfaces that are substantially arcuate to assist in the insertion of seal anchor member  1000  through an incision “I” in tissue “T.” 
     Intermediate portion  1060  of seal anchor member  1000  extends longitudinally between proximal and distal ends  1020 ,  1040 , respectively, of seal anchor member  1000 . Intermediate portion  1006  varies in diameter along a length thereof. Accordingly, seal anchor member  1000  defines a cross-sectional dimension that varies along a length thereof to facilitate the anchoring of seal anchor member  1000  within an incision in tissue. In one embodiment, seal anchor member  1000  defines an “hour-glass” shape or configuration to assist in anchoring seal anchor member  1000  within an incision in tissue. In cross-section, intermediate portion  1060  may exhibit any suitable configuration, e.g., substantially circular, oval or oblong. 
     Each port  108  extending through anchor seal member  1000  is configured to removably receive a surgical instrument (e.g., access instrument  10 ) therethrough. Prior to the insertion of surgical instrumentation, each of ports  1080  is disposed in a first state wherein each of ports  1080  defines a first or initial dimension D 1  ( FIG. 6 ). Initial dimension D 1  ( FIG. 6 ) may be about 0 mm such that the escape of insufflation gas (not shown) through ports  1080  of seal anchor member  1000  in the absence of a surgical instrument inserted therethrough is substantially inhibited. For example, each port  1080  may be configured as a slit extending longitudinal through seal anchor member  1000 . Upon the introduction of surgical instrumentation through one (or more) of ports  1080 , port  1080  transitions to a second state in which port  1080  defines a second, larger dimension D 2  ( FIG. 6 ) that substantially approximates the diameter of the surgical instrument disposed therethrough such that a substantially fluid-tight seal is formed therearound and such that the escape of insufflation gas (not shown) through port  1080  of seal anchor member  1000  is substantially inhibited. 
     The use and function of access instrument  100  in conjunction with seal anchor member  1000  will be discussed during the course of a typical minimally invasive procedure with reference to  FIGS. 4A-7 . However, it is envisioned that the cannula assembly, i.e., access instrument  100  and obturator  500 , may be configured for use independently of seal anchor member  1000  and/or in conjunction with any other suitable seal member (not shown). 
     Initially, the peritoneal cavity (not shown) is insufflated with a suitable biocompatible gas, e.g., CO 2  gas, such that the cavity wall is raised and lifted away from the internal organs and tissue housed therein, providing greater access thereto. The insufflation may be performed with an insufflation needle or similar device, as is conventional in the art. Either prior or subsequent to insufflation, an incision “I” is created in tissue “T”, the dimensions of which may be varied dependent upon the nature of the procedure. 
     Prior to the insertion of seal anchor member  1000  within the incision in tissue, seal anchor member  1000  is in its expanded condition in which the dimensions thereof inhibit the insertion of seal anchor member  1000  into the incision “I” in tissue “T.” To facilitate insertion, the clinician transitions seal anchor member  1000  into the compressed condition by applying a force thereto, e.g., by squeezing seal anchor member  1000 . This applied force acts to reduce the radial dimensions of the proximal and distal ends  1020 ,  1040 , respectively, of anchor seal member  1000  and similarly reduces the radial dimension of intermediate portion  1060  such that seal anchor member  1000  may be inserted into the incision “I” in tissue “T.” Subsequent to insertion, distal end  1040  of seal anchor member  1000  is positioned beneath tissue “T” at which time seal anchor member  1000  may be allowed to transition from the compressed condition back to the expanded condition by removing the force thereon. 
     During the transition from the compressed condition to the expanded condition, the dimensions of seal anchor member  1000  are increased such that intermediate portion  1060  creates an internal biasing force that is directed outwardly and exerted upon surrounding tissue, thereby creating a substantially fluid-tight seal between the seal anchor member  1000  and surrounding tissue, while proximal and distal ends  1020 ,  1040 , respectively, extend radially from the incision “I” in tissue “T” on the respective external and internal surfaces thereof. Thus, once in position, seal anchor member seals, or inhibits the escape of insufflation gas from the internal surgical site. 
     Once seal anchor member  1000  is positioned within the incision “I” in tissue “T,” as described above, one or more surgical instruments may be inserted through ports  1080 . Surgical instrumentation introduced through one of ports  1080  may be any suitable surgical instrument and, accordingly, may vary in size. Suitable surgical instruments may include graspers, forceps, clip-appliers, staplers, etc. Other access instruments such as, for example, access instrument  100 , may also be introduced through seal anchor member  1000  such that additional surgical instrumentation may be inserted through access instrument  100  (once obturator  500  has been removed from lumen  110  of access instrument  100 ) and advanced to the surgical site. 
     More specifically, with obturator  500  inserted trough access instrument  100 , as shown in  FIG. 4B , the access assembly may be inserted, lead by pointed distal tip  507  of obturator  500 , through one of ports  1080 , enlarging port  1080  and thereby transitioning port  1080  into the second state in which port  1080  defines a second dimension D 2  that substantially approximates the diameter of access instrument  100 , creating a substantially fluid tight seal about access instrument  100  and inhibiting the escape of insufflation gas (not shown) through port  1080  of seal anchor member  1000 , as discussed above. Access instrument  100  may then be advanced into position adjacent the internal surgical site. 
     With reference now to  FIG. 7 , once access instrument  100  is disposed through access portal  1000 , as shown in  FIG. 6 , and is positioned as desired for the particular minimally-invasive surgical procedure to be performed at the internal surgical site, obturator  500  may be removed from access instrument  100 . As such, other surgical instrumentation, e.g., surgical grasper “S,” may be inserted through opening  110  of access instrument  100  to perform a minimally-invasive surgical procedure at the internal surgical site. One surgical instrument contemplated will have a flexible section adapted to conform or follow the pre-bent or curved configuration of access instrument  10 . Such instruments with flexible shafts are disclosed in commonly assigned U.S. Pat. Nos. 4,473,077 and 7,546,993 and U.S. Patent Publication No. 2009/0090765, the entire contents of each disclosure being incorporated herein. As mentioned above, instrument seal  112  maintains a fluid-tight seal about surgical grasper “S” when inserted through access instrument  100 . Additionally, the pre-bent, or curved configuration of access instrument  100  helps prevent interference, tangling, or “chop-sticking” of surgical instrumentation inserted through the various ports  1080  of seal anchor member  1000 , particularly where multiple surgical instruments are inserted through seal anchor member  1000  and/or where multiple seal ports, e.g., seal anchor members  1000 , are used. 
     From the foregoing and with reference to the various figure drawings, those skilled in the art will appreciate that certain modifications can also be made to the present disclosure without departing from the scope of the same. While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.