Abstract:
A surgical access system includes a tubular member defining a longitudinal axis and having an axial lumen. The tubular member includes a braided material adapted to expand from a first initial condition having a first cross-sectional dimension to a second expanded condition having a second-cross sectional dimension greater than the first cross-sectional dimension. The tubular member defines an oblique end surface. An access housing is mounted to the tubular member. The access housing is dimensioned for engagement by the user. A process for manufacturing a surgical access device is also disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 60/512,548, filed on Oct. 17, 2003, the entire disclosure of which is hereby incorporated by reference herein. 
     
    
       [0002]    BACKGROUND 
         [0003]    1. Field of the Disclosure 
         [0004]    The present disclosure relates generally to an apparatus and method for providing percutaneous access to an internal operative site during a surgical procedure. More particularly, the present invention relates to an access system which can be percutaneously introduced in a narrow diameter configuration and thereafter radially expanded to accommodate passage of larger diameter surgical instruments. The present disclosure is further related to a process of manufacture of the access system. 
         [0005]    2. Description of the Prior Art 
         [0006]    Minimally invasive surgical procedures involve percutaneously accessing an internal surgical site with small-diameter access tubes (typically 5 to 12 mm), usually referred to as trocars, which penetrate the skin and permit access to the desired surgical site. A viewing scope is introduced through one such trocar, and the surgeon operates using instruments introduced through other appropriately placed trocars while viewing the operative site on a video monitor connected to the viewing scope. The surgeon is thus able to perform a wide variety of surgical procedures requiring only several 5 to 12 mm punctures at the surgical site. Patient trauma and recovery time are thus greatly reduced. 
         [0007]    Minimally invasive surgical procedures include laparoscopic procedures which involve the insufflation of the patient&#39;s abdominal region to raise the abdominal wall and create sufficient operating space to perform a desired procedure. The trocars used in laparoscopic procedures incorporate a valve to permit passage of the scope or surgical instruments while inhibiting leakage of the insufflating gas. It has also been proposed to perform laparoscopic procedures by mechanically expanding the abdomen rather than using insufflation. 
         [0008]    Other minimally invasive surgical procedures include thoracoscopic procedures performed in the region of the chest, arthroscopic procedures performed in body joints, particularly the knee, gynecological laparoscopic procedures, and endoscopic surgical procedures performed in various regions of the body, typically with a flexible scope. These latter procedures do not normally employ pressurization and the trocars used generally do not include pressure valves at their proximal ends. 
         [0009]    The design of suitable trocars must fulfill many requirements, particularly for those used in laparoscopic procedures in a pressurized environment. Trocars should be introducible within the patient with minimum trauma and with minimum risk of injury to internal organs. The trocars used in laparoscopic procedures should be readily sealable to inhibit the leakage of gas from the abdomen, and, in particular, should be designed to inhibit leakage in the region surrounding the external periphery of the trocar which passes through the abdominal wall. It is further desirable that trocars incorporate structure for anchoring within the percutaneous passage, and it would be particularly desirable if a single trocar could accommodate instruments having a wide variety of cross-sectional shapes and sizes. 
         [0010]    Commonly assigned U.S. Pat. No. 5,431,676 to Dubrul et al., the contents of which are incorporated herein by reference in its entirety, discloses in certain embodiments an access system incorporating an elongate dilation member and an expansion member receivable within an axial lumen of the trocar. The dilation member includes a tubular braid which is radially expandable from a small diameter configuration to a large diameter configuration. A removable sheath may cover the braid. In use, the dilation member is percutaneously introduced to a target site within a patient&#39;s body, e.g., within the abdomen of the patient. The expansion member is thereafter introduced within the dilation member to break the sheath and radially expand the tubular braid to provide a desired diameter access lumen. The device disclosed in Dubrul &#39;676 has proven to be highly effective in conjunction with laparoscopic and other minimally invasive surgical procedures. However, it would be desirable to include features facilitating the insertion of the expansion member and for facilitating insertion of the dilation member into the body. In addition, efficient and effective methods of manufacturing the process system are desirable. 
       SUMMARY 
       [0011]    Accordingly, the present disclosure relates to an improved apparatus, system and method for forming and enlarging percutaneous penetrations into target locations within a patient&#39;s body. In one preferred embodiment, a surgical access system includes a tubular member defining a longitudinal axis and having an axial lumen. The tubular member comprises a braided material adapted to expand from a first initial condition having a first cross-sectional dimension to a second expanded condition having a second-cross sectional dimension greater than the first cross-sectional dimension. The tubular member defines an oblique end surface. An access housing is mounted to the tubular braid and is dimensioned for engagement by the user. 
         [0012]    The tubular member includes a mounting element mounted therewithin. The mounting element facilitates attachment of the tubular member to the access housing. The mounting element is dimensioned to frictionally engage an internal wall portion of the tubular member. The access housing may include a base and a cover mountable to the base. The base is adapted to receive a proximal end of the tubular member and the mounting element is engageable with a locking shelf of the base. The access housing may further include a seal element mounted within the base and defining an aperture for sealed reception of an elongate object. 
         [0013]    The surgical access system may further include a dilator member. The dilator member is adapted for insertion within the tubular braid to expand the tubular braid between the first and second conditions. The dilator member is preferably a cannula. 
         [0014]    A process for manufacturing a surgical access device, includes the steps of:
       providing a tubular braid, the braid defining a longitudinal axis and having an axial lumen, the tubular braid adapted to expand from a first initial condition having a first cross-sectional dimension to a second expanded condition having a second-cross sectional dimension greater than the first cross-sectional dimension;   positioning an elastomer layer over at least a portion of the tubular braid; subjecting the elastomer layer and the tubular braid to heat to thereby form an elastomer-braid subassembly;   creating a flared end portion of the elastomer-braid subassembly; inserting the elastomer-braid subassembly within an access housing base; and   securing an access housing hub to the access housing base whereby at least the flared end portion of the elastomer-braid subassembly is secured within the access housing hub and the access housing base.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    Preferred embodiments of the present disclosure will be better appreciated by reference to the drawings wherein: 
           [0020]      FIG. 1  is an elevational view of the access apparatus in accordance with an embodiment of the present disclosure; 
           [0021]      FIG. 2  is a an exploded perspective view of the access apparatus in accordance with the embodiment of  FIG. 1  with parts separated; 
           [0022]      FIG. 3  is a cross-sectional view of the access apparatus in accordance with the embodiment of  FIGS. 1-2 ; 
           [0023]      FIG. 4  is an enlarged cross-sectional view of the proximal end of the access apparatus in accordance with the embodiment of  FIGS. 1-3 ; 
           [0024]      FIG. 5  is a flow chart depicting a preferred method of manufacture of the access apparatus in accordance with the further embodiment of the invention; 
           [0025]      FIG. 6  is a view illustrating the elastomer cover of the access apparatus; 
           [0026]      FIG. 7  is a view illustrating a building mandrel utilized for assembly of the access apparatus in accordance with the embodiment of  FIG. 5 ; 
           [0027]      FIG. 8  is a view of PTFE tubing which is mounted over the access apparatus in accordance with the embodiment of  FIGS. 1-4 ; 
           [0028]      FIG. 9  is a view illustrating the distal end of the access apparatus with a needle positioned therein; 
           [0029]      FIG. 10  is a cross-sectional view illustrating use of the access apparatus in accordance with the embodiment of  FIGS. 1-4  to access a tissue site; 
           [0030]      FIG. 11  is a cross-sectional view of a dilator for the access apparatus in accordance with the embodiment of  FIGS. 1-4  and  7 - 8 ; and 
           [0031]      FIG. 12  is a cross-sectional view illustrating the use of the access apparatus in accordance with the embodiment of  FIGS. 1-4  and  7 - 9 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    The principles of the present disclosure are applicable to a variety of surgical access devices adapted for permitting percutaneous access to a target site. These access devices include, but are not limited to, trocars and/or cannulas, catheters, hand access devices, scopes, etc. The present disclosure is contemplated for use in various surgical procedures including, e.g., laparoscopic, arthroscopic, thoracic, etc. 
         [0033]    The following discussion will initially focus on the structure and components of the novel access device followed by a preferred method of manufacture thereof A method of use of the apparatus will be subsequently discussed. 
         [0034]    In the following description, as is traditional, the term “proximal” will refer to the portion of the instrument closest to the operator while the term “distal” refers to the portion of the instrument most remote from the operator. 
         [0035]    Referring now to the drawings wherein like reference numerals identify similar or like elements throughout the several views,  FIGS. 1-4  illustrate the novel access apparatus in accordance with the principles of the present disclosure. Access device  10  generally includes housing  12  and elongate member  14  extending from the housing  12 . Housing  12  and elongate member  14  define a longitudinal axis “a” which extends through and along the length of the device  10 . 
         [0036]    With continued reference to  FIGS. 1-4 , housing  12  includes several components, which, when assembled, define a structure advantageously dimensioned to be held by the surgeon. These components include base  16 , hub  18 , seal  20  and cover  22 . Base  16  defines an outer wall  24  having a plurality of spaced recesses  26  therein. Recesses  26  are generally rectangular in configuration as shown. The interior of base  16  has transverse ledge  28  upon which hub  18  rests and locking shelf  30  adjacent the proximal end of the base  16 . Base  16  defines a distal tapered portion  32  which tapers inwardly relative to the longitudinal axis “a”. In the preferred embodiment, tapered portion  32  incorporates a pair of intersecting surfaces  32   a,    32   b  and a transverse shelf  32   c . Tapered portion  32  functions in securing elongate member  14  to base  16  as will be discussed. 
         [0037]    Hub  18  of housing  12  includes disc-shaped portion  34  and annular wall  36  extending distally from the disc-shaped portion  34 . Disc-shaped portion  34  has a plurality of vertical locks  38  extending upwardly from the disc-shaped portion  34 . Vertical locks  38  are received within correspondingly positioned and dimensioned recesses  26  of base  16  in the assembled condition of housing  12 . Vertical locks  38  each have an internal locking shelf  38   a,  which in combination with shelves  30  of the base  16  defines a continuous locking shelf when hub  18  is assembled within the base  16 . Annular wall  36  of hub  18  is generally continuous and defines a diameter which is less than the effective internal diameter of base  16 , and/or the effective diameter of the proximal end of elongate member  14 . Annular wall  36  is received within base  16  and elongate member  14  upon assembly of the device  10 . Hub  18  further includes a resilient seal or o-ring  40  which is accommodated within groove  42  disposed on the underside of the hub  18 . O-ring  40  is adapted to form a gas-tight seal between hub  18  and base  16 . 
         [0038]    With continued reference to  FIGS. 1-4 , seal  20  includes an outer circumferential wall  44  and an inner seal portion  46  extending radially inwardly relative to the longitudinal axis “a”. Inner seal portion  46  defines central aperture  48  which is dimensioned for passage of an object, e.g., a surgical instrument, guide wire, catheter or the hand of a surgeon. Seal  20  may be fabricated from any elastomeric material suitable for its intended purpose. A friction resisting coating may be applied to seal  20 . Other valve types are also contemplated including zero-closure valves, slit valves, septum valves, double-slit valves, inflatable bladders, foam or gel valve arrangements, etc. 
         [0039]    Cover  22  has a general annular shape as shown defining a central opening  50  for permitting passage of the object. Cover  22  includes circumferential recess  52  on its underside or distal end face which accommodates outer circumferential wall  44  of seal  20 . The peripheral area of cover  22  defines a ledge or shelf  54  which, in the assembled condition, engages locking shelf  30  of base  16  and/or locking shelf  38   a  of vertical locks  38  of hub  18  in snap relation therewith to thereby secure the remaining components of housing  12  within the base  16 . Other mechanical arrangements for securing cover  22  to base  16  are also envisioned including, e.g., a screw thread arrangement, bayonet coupling, etc. 
         [0040]    The components of housing  12  may be fabricated from any suitable generally rigid material (notwithstanding seal) including stainless steel, titanium or a rigid polymeric material. The components of housing  12  may be fabricated from any suitable medical grade material. 
         [0041]    Referring still to  FIGS. 1-4 , elongate member  14  will be discussed. Elongate member  14  defines a general tubular shape having proximal end  56  and distal end  58 . Proximal end  56  is flared radially outwardly in a proximal direction and secured to housing  12 . Distal end  58  includes an inclined surface  58   a  obliquely arranged relative to the longitudinal axis. This surface  58   a  facilitates passage of elongate member  14  through the tissue. Tubular elongate member  14  may be fabricated from any material which is capable of receiving the assembly of a cannula, dilator, or surgical instrument and capable of radial expansion of the elongate member  14 . The materials are desirably medical grade materials including polymers and metals. In an exemplary embodiment, elongate member  14  includes a braided material of inelastic filaments covered by an elastomeric membrane of, e.g., urethane, or any elastomeric material or as generally disclosed in commonly assigned U.S. Pat. Nos. 5,431,676 and 6,245,052, the contents of each being incorporated herein by reference. It is also envisioned that a polyethylene sheath may be assembled over elongate member  14 . The elongate member may comprise an elastomeric member or members without the braided material. Embodiments may include a material incorporating filaments, where the filaments may be elastic, inelastic, monofilaments, multifilaments, braided, woven, knitted or non-woven materials. The elongate member may comprise a braided, woven, knitted or non-woven material with or without an elastomeric membrane. 
         [0042]    With particular reference to  FIG. 4 , elongate member  14  has a mounting element or ring  60  which is anchored within elongate member  14  adjacent proximal end  56 . Mounting ring  60  is preferably retained within the proximal end  56  of elongate member  14  through a frictional arrangement or relationship created between the proximal end  56  of elongate member  14  and the mounting ring  60  as will be further discussed hereinbelow. Mounting ring  60  assists in securing elongate member  14  to housing  12 . 
       Preferred Process of Manufacture of Access Device 
       [0043]    The preferred process or method of manufacture of access device  10  will now be discussed. Referring now to the flow chart (STEP  200 ) of  FIG. 5 , the first step of the process is to prepare elongate member  14 . As mentioned hereinabove, elongate member  14  is preferably a tubular braid. Tubular braids suitable for use as an access device are commercially available from, e.g., textile manufacturers, and, in particular, textile manufacturers specializing in medical devices. Tubular braid is preferably cut to a desired length as dictated by the desired surgical objective for which device  10  will be used, illustrated as (STEP  210 ). 
         [0044]    With continued reference to  FIG. 5 , an elastomer cover  13 , preferably, a urethane cover is provided and cut to the desired length to correspond to the length of the tubular braid (STEP  220 ).  FIG. 6  depicts a preferred arrangement of urethane cover  13 . 
         [0045]    The urethane cover  13  preferably has a flared proximal portion  15  to define an inner diameter which increases toward the proximal end of the urethane cover  13 . Such flaring of the end of urethane cover  13  may be effectuated by conventional extrusion processes used in forming the urethane cover  13 . Preferably, the thickness of the material of the elastomer cover including the flared portion  15  is constant throughout its length. Thereafter, the tubular braid  17  is positioned within the urethane cover (STEP  230 ) to assemble the unit. 
         [0046]    With elastomer cover  13  appropriately placed over the tubular braid, the assembly is subjected to a heating process (STEP  240 ) by positioning the assembly within an oven. In addition, pressure is applied by applying a vacuum, using a press or mold, so as to press the heated cover  13  into the braid. As a result of the heating process, the elastomer, e.g., urethane, becomes embedded within the fabric of the tubular braid to define a tubular braid/elastomer assembly. The assembly is thereafter cooled for a period of time. 
         [0047]    The components of housing  12  and elongate member  14  are then assembled. In the preferred embodiment, a building or centering mandrel is utilized to assemble the components. A preferred mandrel is depicted in  FIG. 7 . This mandrel  100  includes a frusto-conical head  102  and a general rod-shaped element  104  extending from the head  102 . Initially, mounting ring  60  is placed onto the mandrel  100 . The elongate member  14  (comprising the tubular braid/elastomer assembly) is then slid over the mandrel  100  to a position where mounting ring  60  is received within the flared proximal end of the assembly as depicted in  FIG. 7 . (STEP  250 ) It is envisioned that the proximal end of the elongate member may stretch to an expanded position to receive mounting ring  60 . In this arrangement, mounting ring  60  is preferably frictionally secured within the assembly  14  adjacent the proximal end. The elongate member  14  is then ground or cut at the distal end to the oblique surface  58   a  depicted in  FIG. 1 . 
         [0048]    The elongate member  14  and mounting ring  60  are removed from the mandrel  100 . At this point in the process, an outer plastic tubing, desirably PTFE tubing, may be placed onto the elongate member  14  (STEP  260 ).  FIG. 8  depicts the preferred tubing. The proximal end  66  of the tubing  62  may be partially separated or weakened to facilitate its detachment. Alternatively, the PTFE tubing  62  may be scored along a score line  64  to facilitate detachment during use. The tubing  62  may be secured to the tubular braid/elastomer assembly adjacent its proximal end or mounting ring  60  with an adhesive or glue. Desirably, the tubing  62  extends beyond the oblique surface  58   a,  as shown in  FIG. 9 .  FIG. 9  depicts the distal end of elongate member  14 , with a needle  200  extending out of elongate member  14 . The tubing  62  provides smooth transition from needle  200  and the oblique surface  58   a.  The needle  200  may be provided with the apparatus  10  as part of a kit or system for use during the surgical procedure. 
         [0049]    With reference to  FIGS. 3-4 , in conjunction with  FIG. 5 , assembly is continued by positioning the elongate member  14  within base  16  of housing  12  such that mounting ring  60  is positioned within the interior of the base  16  (STEP  270 ). The tubular braid, cover  13 , and tubing  62  is desirably folded over the ring  60 , so that the elongate member  14  is captured between more than two surfaces of the housing, as shown in  FIG. 4 . Mounting ring  60  preferably causes tapered portion  32  of base  16  to deflect radially outwardly whereby, subsequent to positioning within the base  16 , the mounting ring  60  engages transverse shelf  32   c  of the base  16 . Thereafter, the assembly of housing  12  is continued (STEP  280 ). Seal  40  is placed in base  16  and hub  18  is assembled within base  16 . In this position, annular wall  36  of hub  18  is received within mounting ring  60  and vertical locks  38  are received within recesses  26  of base  16 . Thereafter, seal  18  is positioned within base  16 , over the hub  18 . Assembly is continued by mounting cover  22  to base  16  whereby shelf  54  of the cover  22  engages locking shelf  30  of base  16  to secure the components together. Outer circumferential wall  44  of seal  18  is accommodated within circumferential recess  52  of cover  22 . Cover  22  secures the remaining components within base  16 . It is envisioned that in the assembled condition mounting ring  60  may be pressed against the proximal end of elongate member  14  to compress the member  14  against tapered portion  32  of base  16 . In addition, mounting ring  60  is prevented from release from base  16  by engagement with internal shelf  32   c  of the base  16 . The elongate member  14  is mechanically secured in the housing  12 , by being captured between the base  16  and hub  18 . 
       Use of the Apparatus 
       [0050]    A method of use of the apparatus  10  will now be discussed. As depicted in  FIG. 10 , device  10  is percutaneously introduced to access a target site beneath the patient&#39;s skin. Preferably a needle or trocar  200  positioned in the device  10  to facilitate entry through the surgical site as discussed in connection with  FIG. 9 . It is noted that oblique end  58   a  of elongate member  14  facilitates passage of access device  10  within the tissue. The needle or trocar is thereafter withdrawn leaving access device  10  within the tissue. Desirably, a pneumoneedle is used for entry through the patient&#39;s skin and underlying layers and then used to introduce insufflation gas, in the case of laparoscopic surgery. 
         [0051]    Referring to  FIG. 11 , a cannula  300  is then introduced within the inner lumen of the expandable elongate member  14  to expand the tubular braid/elastomer assembly to a desired internal diameter. The expansion of the elongate member  14  breaks the PTFE tubing  62 . In the preferred embodiment, cannula  300  includes cannula housing  302  and a cannula sleeve  304  extending from the housing. Cannula sleeve  304  has an external threaded portion  306 . The diameter of cannula sleeve  304  is greater than the internal diameter of elongate member  14 . Cannula  300  is preferably rotated whereby the threaded portion  306  advances the cannula sleeve  304  within elongate member  14  of access device. The housing  12  desirably includes a flange for engaging the threaded portion  306 . In one embodiment, adjacent threads of threaded portion  306  engage surfaces  22   a  of cover  22  and surfaces  18   a  of hub  18  to advance cannula  300  upon rotation of the cannula  300 , i.e., surfaces  18   a,    22   a  function as an internal thread structure which is engaged by threaded portion  306  to advance the cannula  300 . Upon advancement, elongate member  14  expands to a second enlarged diameter shown in  FIG. 11 . The threaded portion enables the advancement of cannula  300  while minimizing the force directed in the distal direction. The threaded portion  306  may additionally be arranged for engaging the tissue. 
         [0052]    It is envisioned that prior to insertion of cannula sleeve  304 , elongate member  14  may be expanded with a dilator (not shown). It is also envisioned that the cannula sleeve  304  may be devoid of threads. Surgical instruments, scopes, etc.  400  may be introduced through the cannula to perform the desired procedure as shown in  FIG. 12 . After the procedure is finished, the cannula  300  is removed which causes tubular braid/elastomer assembly to collapse for subsequent removal. Optionally, other different diameter dilators or cannulas may be advanced within device  10  as desired. 
         [0053]    It will be understood that various modifications may be made to the embodiments disclosed herein. For example, in a further embodiment, the base has a flange arranged for deflecting to receive the mounting ring  60 , in a snap-fit manner so as to fixedly retain the ring  60 . Although the ring depicted in the figures is round, the ring may have polygonal or oval shapes. 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 appended hereto.