Abstract:
An obturator assembly is presented including an obturator housing, an obturator shaft operably connected to the obturator housing and defining a longitudinal axis, and proximal and distal ends, and a penetrating member adjacent the distal end of the obturator shaft. The obturator assembly also includes an instrument retention mechanism mounted on a top portion of the obturator housing and adapted for securing and stabilizing surgical instruments, e.g., endoscopes, inserted into the obturator, thereby permitting visualization of tissue as the tissue is being penetrated by the penetrating member.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/660,866, filed on Jun. 18, 2012, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to an obturator assembly. More particularly, the present disclosure relates to a bladeless optical obturator assembly having an instrument retention mechanism mounted on an obturator housing. 
         [0004]    2. Background of Related Art 
         [0005]    Minimally invasive procedures are continually increasing in number and variation. Forming a relatively small diameter, temporary pathway to the surgical site is a key feature of most minimally invasive surgical procedures. The most common method of providing such a pathway is by inserting a trocar assembly through the skin. Common trocar assemblies generally include an obturator assembly for penetrating the skin and a cannula assembly for providing a sealed passageway for insertion of surgical instruments into a body cavity. In many procedures, the trocar assembly is inserted into a body cavity of a patient and the body cavity is insufflated to provide a working space. Upon removal of the obturator assembly, the cannula assembly is utilized to provide the necessary pathway to the surgical site while minimizing leakage of insufflation gases. The obturator assembly may include a safety shield which protects against unintentional puncturing by a sharpened tip of the obturator assembly. 
         [0006]    During certain particularly delicate operations, care is required to prevent underlying organs from being punctured by the sharpened tip of the obturator assembly. Therefore, it is desirable to provide an obturator assembly which includes safety mechanisms to prevent engagement of the sharpened tip of the obturator assembly with the underlying organs. It is further desirable to provide an obturator assembly having an obturator member and a bladeless penetrating member. 
       SUMMARY 
       [0007]    The present invention, according to various embodiments thereof, is directed to an obturator assembly for penetrating tissue and being at least partially positionable within a cannula assembly. The obturator assembly includes an obturator housing, an obturator shaft operably connected to the obturator housing and defining a longitudinal axis, and proximal and distal ends, and a penetrating member, e.g., which may be bladeless or sharp, adjacent the distal end of the obturator shaft. Additionally, the obturator assembly includes an instrument retention mechanism mounted on a top portion of the obturator housing and adapted for securing and stabilizing surgical instruments, e.g., endoscopes, inserted therethrough. 
         [0008]    In further embodiments, the instrument retention mechanism may include an inner portion constructed from a first material having a first hardness value and an outer portion constructed from a second material having a second hardness value, the second hardness value being greater than the first hardness value. The inner portion of the instrument retention mechanism may include at least one ribbed protrusion configured to secure and stabilize the instrument retention mechanism to the top portion of the obturator housing. 
         [0009]    In yet another embodiment, the instrument retention mechanism may include a pair of opposed extensions configured to facilitate securement of the instrument retention mechanism to the top portion of the obturator housing. The pair of opposed extensions may each include a rib member extending thereon. 
         [0010]    Additionally, the instrument retention mechanism may include a centrally disposed opening for receiving the surgical instruments inserted therethrough, the opening including at least one pair of opposed slits adjacent to or in communication with the opening. 
         [0011]    In yet another embodiment, the obturator shaft may include a plurality of equally spaced apart openings extending thereon. 
         [0012]    Moreover, the bladeless penetrating member may define, from leading to trailing, a cylindrical element having a generally arcuate leading surface and a generally planar dissecting element extending from the cylindrical element. Alternatively, the penetrating member may define a dolphin-nose shape, e.g., having opposed concave surfaces circumferentially spaced between opposed convex surfaces. 
         [0013]    In addition, the present invention, in various embodiments thereof, is directed to a trocar assembly for penetrating tissue. The trocar assembly includes a cannula assembly including a cannula housing and a cannula sleeve extending distally from the cannula housing and an obturator assembly, which may be an optical obturator assembly, at least partially positionable within the cannula assembly and being adapted to pass through tissue, the obturator assembly being removable from the cannula assembly subsequent to accessing an underlying tissue site. The obturator assembly may include an obturator housing, an obturator shaft connected to the obturator housing and defining a longitudinal axis, and proximal and distal ends, and a penetrating member, e.g., bladeless, adjacent the distal end of the obturator shaft. Additionally, the obturator assembly includes an instrument retention mechanism mounted on a top, e.g., proximal, portion of the obturator housing and adapted for securing and stabilizing surgical instruments inserted therethrough. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: 
           [0015]      FIG. 1  is a perspective view of a trocar assembly including an obturator assembly and a cannula assembly, in accordance with the present disclosure; 
           [0016]      FIG. 2  is a perspective view of the trocar assembly of  FIG. 1  illustrating the obturator assembly separated from the cannula assembly, in accordance with the present disclosure; 
           [0017]      FIG. 3  is a perspective view of the obturator assembly, in accordance with the present disclosure; 
           [0018]      FIG. 4A  is a top, perspective view of the obturator assembly illustrating the instrument retention mechanism, in accordance with the present disclosure; 
           [0019]      FIG. 4B  is a top, perspective view of the instrument retention mechanism, in accordance with the present disclosure; 
           [0020]      FIG. 4C  is a bottom, perspective view of the instrument retention mechanism, in accordance with the present disclosure; 
           [0021]      FIG. 5  is a side, cross-sectional view of a top portion of the obturator assembly, in accordance with the present disclosure; 
           [0022]      FIG. 6  is a side, cross-sectional view of a top portion of the obturator assembly illustrating the pair of opposed extensions, in accordance with the present disclosure; and 
           [0023]      FIG. 7  is a perspective view of a distal end of the obturator assembly illustrating the bladeless penetrating member, in accordance with the present disclosure. 
       
    
    
       [0024]    The figures depict preferred embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the present disclosure described herein. 
       DETAILED DESCRIPTION 
       [0025]    Embodiments of the presently disclosed apparatus will now be described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views. As used herein, the term “distal” refers to that portion of the tool, or component thereof, which is further from the user while the term “proximal” refers to that portion of the tool or component thereof which is closer to the user. 
         [0026]    Referring to  FIGS. 1 and 2 , there is disclosed a trocar assembly  10  including a cannula assembly  12  and an obturator assembly  14  positioned through cannula assembly  12 . Cannula assembly  12  provides an access port for various surgical instruments into the body as well as a conduit for a source of insufflation fluid to insufflate the body to create a working cavity. 
         [0027]    With reference to  FIG. 2 , cannula assembly  12  includes a cannula housing  16  and elongate cannula sleeve  18  extending distally from cannula housing  16 . Cannula housing  16  and cannula sleeve  18  define a throughbore  20 , which extends from a proximal end  22  of cannula housing  16  to a distal end  24  of cannula sleeve  18 . A valve  26  is provided on cannula housing  16  to receive a source of insufflation fluid for passage into the body of a patient. The cannula sleeve  18  may also include a plurality of ribs  36 . The plurality of ribs  36  may be a plurality of protrusions or a plurality of recesses. 
         [0028]    With reference to  FIG. 2 , obturator assembly  14  generally includes an obturator housing  38  and an elongate member  40  extending distally from, and movably mounted within, obturator housing  38 . Obturator assembly  14  is additionally provided with a pair of wings  32  to facilitate securing cannula assembly  12  to the body of a patient. Obturator assembly  14  also includes an instrument retention mechanism  30 , which is preferably releasably mounted to obturator housing  38 . The instrument retention mechanism  30  is mounted on a top portion of the obturator housing  38  and adapted for securing and stabilizing surgical instruments, e.g., an endoscope, inserted therethrough. Methodologies for releasably connecting instrument retention mechanism  30  to obturator housing  38  may include a bayonet coupling, threaded connection, latch, friction fit, tongue and groove arrangements, snap-fit, etc. Preferably, obturator housing  38  is configured and dimensioned to functionally cooperate with cannulas that range in size, e.g., from about 5 mm to about 15 mm in diameter. 
         [0029]    With reference to  FIG. 3 , a side view of the obturator assembly  14 , in accordance with the present disclosure is presented. For sake of clarity, similar elements described with reference to  FIGS. 1 and 2  will not be described with reference to  FIG. 3 . The side view of the obturator assembly  14  illustrates a plurality of openings  50  disposed across the length of the elongate member  40 . The plurality of openings  50  may be formed by core support pins to prevent deflection of a core pin (not shown) during the manufacturing of the obturator assembly  14 , as is well known in the art. 
         [0030]    With reference to  FIG. 4A , a perspective view of a top, perspective view of the obturator assembly  14  illustrating the instrument retention mechanism  30 , in accordance with the present disclosure is presented. With reference to  FIG. 4B , a top, perspective view of the instrument retention mechanism  30 , in accordance with the present disclosure is presented. The instrument retention mechanism  30  includes an opening  60  having at least one pair of opposed slits  61 . The opening  60  is configured to receive, for example, a surgical instrument therethrough. The opening  60 , in conjunction with the slits  61 , is dimensioned and adapted to releasably secure the one or more surgical instruments inserted therethrough. 
         [0031]    With reference to  FIG. 4C , a bottom, perspective view of the instrument retention mechanism  30 , in accordance with the present disclosure is presented. The bottom view illustrates that the wings  32  include at least one rib member  33  extending thereon. Additionally, the inner portion of the instrument retention mechanism  30  includes at least one ribbed protrusion  70  (or clocking rib) configured to secure and stabilize the instrument retention mechanism  30  to the top portion of the obturator housing  38 . One skilled in the art may contemplate a plurality of ribbed protrusions  70  extending in an equally spaced apart manner across the inner surface of the instrument retention mechanism  30 . 
         [0032]    Moreover, the instrument retention mechanism  30 , as shown in  FIG. 4C , may include an inner portion constructed from a first material having a first hardness value and an outer portion constructed from a second material  35  having a second hardness value, the second hardness value being greater than the first hardness value. Therefore, one skilled in the art may contemplate portions of the instrument retention mechanism  30  being constructed from different materials having different hardness values in order to optimize the stabilization of the instrument retention mechanism  30  onto the obturator housing  38  and to optimize the stabilization of an instrument, e.g., endoscope, that is removably inserted into the instrument retention mechanism  30 . It should also be noted that the hardness of the materials from which the instrument retention mechanism  30  is constructed may simultaneously be chosen so as to enable the instrument retention mechanism  30  to be removably connected onto the obturator housing  38  by a user, if desired. 
         [0033]    With reference to  FIG. 5 , a side, cross-sectional view  500  of a top portion of the obturator assembly  530 , in accordance with the present disclosure is presented. 
         [0034]    The cross-sectional view  500  depicts instrument retention mechanism  530  having a clamping mechanism  532  for being securedly fitted around the top portion of the obturator housing  514 . The obturator housing  514  includes an obturator shaft  540  extending therefrom. The instrument retention mechanism  530  also includes a centrally disposed opening  560  for receiving at least one surgical instrument. The surface  525  of the obturator housing  514  is configured to encourage the instrument retention mechanism  530  to snap into place in the correct orientation. It is contemplated that the clamping mechanism  532  is constructed of a material having a greater hardness than the material used to construct the rest of the instrument retention mechanism  530 . 
         [0035]    With reference to  FIG. 6 , a cross-sectional view  600  of a top portion of the obturator assembly illustrating the pair of opposed extensions  632 , in accordance with the present disclosure is presented. 
         [0036]    The cross-sectional view  600  illustrates the ribbed protrusion  670  (or clocking rib), which prevents internal geometry of the obturator assembly from being distorted or misaligned during the manufacturing process. The ribbed protrusion  670  may releasably cooperate with at least one recess  672  within the inner portions of the obturator assembly. The instrument retention mechanism  630  is also shown having a centrally disposed opening  660  for receiving at least one surgical instrument therethrough. The surface  625  of the obturator housing is configured to encourage the instrument retention mechanism  630  to snap into place in the correct orientation. It is contemplated that the clamping mechanism  632  is constructed of a material having a greater hardness than the material used to construct the rest of the instrument retention mechanism  630 . The clamping mechanism  632  may be a pair of wings utilized to facilitate an assembler (not shown) to stretch and fit the instrument retention mechanism  630  to the obturator housing. 
         [0037]    Moreover, an inner portion of the obturator shaft  641  may be hollow so as to permit the insertion of the one or more surgical instruments, e.g. an endoscope. Also, the obturator shaft  641  may include at least one opening  650 . The opening  650  may be used as a core support to prevent deflection of a core pin (not shown) during the manufacturing of the obturator assembly. 
         [0038]    With reference to  FIG. 7 , a perspective view of a distal end  700  of the obturator assembly illustrating the penetrating member  710 , in accordance with various embodiments of the present disclosure is presented. The penetrating member  710  may be bladeless, so as to provide for dissection through tissue planes/layers. Alternatively, the penetrating member  710  may have sharp edges so as to cut through tissue. 
         [0039]    Penetrating member  710  may be tapered, conical, pyramidal, dolphin-nosed (as explained above), frusto-conical and/or any other configuration suitable for passing through tissue. In various embodiments, penetrating member  710  may, e.g., a dolphin-nose configuration as explained previously, with a rounded distal tip or nub  720  to facilitate initial penetration between tissue layers. 
         [0040]    Penetrating member  710  may be substantially hollow to receive the distal end of, for example, an endoscope (not shown). Penetrating member  710  may be fabricated from any suitable plastic or polymeric material, e.g., polycarbonate, and advantageously is transparent or translucent to enable visualization therethrough. The penetrating member  710  may be either a separate component or integrally formed, e.g., monolithically, with elongate member  740 . Elongate member  740  may be fabricated from the same transparent or translucent material, or alternatively the elongate member  740  may be fabricated from opaque material, such as metal or plastic. 
         [0041]    Various components of the obturator assembly may include any suitable biocompatible metal, such as stainless steel and titanium and its alloys. Alternatively, the optical obturator assembly may include a polymeric material such as polycarbonate, polystyrene. Advantageously, elongate member  740  may be transparent throughout its entire length. Alternatively, only penetrating member  710 , or even certain portions of the penetrating member  710 , may be transparent or translucent. 
         [0042]    Except where noted otherwise, the materials utilized in the components of the presently disclosed trocar assembly generally include materials such as, for example, ABS, polycarbonate, stainless steel, titanium and any other suitable biocompatible metals and/or polymeric materials. A preferred ABS material is CYCOLAC which is available from General Electric. A preferred polycarbonate material is also available from General Electric under the trademark LEXAN. An alternative polycarbonate material which may be utilized is CALIBRE polycarbonate available from Dow Chemical Company. The polycarbonate materials may be partially glass filled for added strength. 
         [0043]    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 particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.