Abstract:
A cannula and trocar assembly, including a septum seal assembly is provided. The septum seal assembly includes a shield and a septum seal for creating a gas-tight seal around a surgical instrument that is inserted into and through the cannula assembly without causing damage to the seal assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This claims the benefit of U.S. Provisional Application No. 61/939,459, filed Feb. 13, 2014. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to medical apparatus seal assemblies, and more particularly to medical and surgical trocar seal assemblies. 
         [0003]    Laparoscopy is a common surgical procedure which uses one or more small incisions and involves carbon dioxide gas being pumped into a patient to expand the abdomen, the process of which is referred to as insufflation. Insufflation allows the surgeon a better view of the internal organs and other internal body parts. A laparoscope is inserted through an incision to look at the internal organs, often times during the surgical procedure, to allow the surgeon to have a precise view of the surgical space. 
         [0004]    It is necessary to retain as much insufflation gas in the abdominal cavity as possible and to maintain a constant gas pressure, while allowing access by instruments. Thus the seal(s) must allow easy access of the instruments through the cannula while retaining as much insufflation gas in the surgical space as reasonably possible in order to maintain the insufflation gas pressure. 
         [0005]    To achieve this function, many different designs of seals have been employed. However, the seal assembly must not only provide a gas-tight or nearly gas-tight seal around an instrument when the instrument is extended into the cannula and into the surgical space, but also preferably allow for some lateral movement or angled movement of the instrument, allow easy insertion and withdrawal of the instrument without damaging the seal, and also employ protection against being damaged by a sharp instrument as it is inserted through the seal assembly. 
         [0006]    The trocar assembly and cannula seal assembly disclosed herein perform all of these functions, while being cost effective to manufacture. One embodiment of the inventive trocar assembly comprises a housing with an opening and a unitary monolithic septum seal having an outer projection attached to the housing. The septum seal has an outer seal wall depending from the outer projection, and an inner seal wall connected to the outer seal wall and positioned inwardly with respect to the outer seal wall, defining a space between the outer seal wall and the inner seal wall. A sealing member extends inwardly from the inner seal wall and has an aperture substantially aligned with the housing opening. The inner seal wall and the sealing member together define an interior seal space. A shield for the protection of the septum seal from being perforated by a surgical instrument resides at least partially within the interior seal space and is expandable to allow different sized instruments to pass through it. 
         [0007]    Another embodiment is a trocar assembly comprising a cannula assembly having a distal tubular portion and a proximal hub portion, a valve at least partially disposed within the cannula proximal hub portion, the valve having an opening to allow entry of an instrument into the distal tubular portion of the cannula, and a seal housing attached to the cannula proximal hub portion. The seal housing has a proximal opening sized to allow a surgical instrument therethrough and has at least one wall defining a seal housing interior. The trocar assembly of this embodiment also includes a unitary monolithic septum seal at least partially disposed within the seal housing interior and which has an outer member attached to the seal housing. The seal has a support member which is attached to the outer member of the septum seal, and a sealing portion is attached to the support member. The sealing portion is substantially cylindrically shaped and has a first end that is open and a second end that is substantially closed by a sealing member which has an aperture therein for receiving an instrument. 
         [0008]    Yet another embodiment is a universal seal assembly for a trocar which includes a housing having an interior and a seal member at least partially disposed within the interior of the housing. The seal member has a proximal lip extending annularly and is engaged with the housing. The lip comprises an inner circumferential portion. A first seal wall extends distally from the inner circumferential portion of the proximal lip and has a distal edge. A second seal wall extends from the distal edge of the first seal wall, with the first seal wall and the second seal wall together defining an outer support member. A third seal wall extends from the second seal wall and a sealing member extends inwardly from the third seal wall, the sealing member having an aperture in it. The third seal wall and the sealing member together define an interior seal space, and the first seal wall, the second seal wall, and the third seal wall are positioned with respect to one another to create an s-shaped structure for allowance for off-axis movement of instruments received by the seal member. 
         [0009]    Other advantages, objects and/or purposes of the invention will be apparent to persons familiar with constructions of this general type upon reading the following specification and inspecting the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a perspective view of a laparoscopic trocar assembly including a cannula assembly, an optical obturator assembly, and a laparoscope. 
           [0011]      FIG. 2  is a perspective view of the cannula assembly of  FIG. 1  with the seal housing removed from the remainder of the cannula assembly. 
           [0012]      FIG. 3  is a bottom plan view of the cannula assembly of  FIG. 1 . 
           [0013]      FIG. 4  is a cross-sectional view of the cannula assembly of  FIG. 1 , taken along lines IV-IV in  FIG. 3 . 
           [0014]      FIG. 5  is a perspective exploded view of the seal housing, seal assembly, and retainer ring of the cannula assembly of  FIG. 1 . 
           [0015]      FIG. 6  is a perspective exploded view of the seal assembly of  FIG. 5 . 
           [0016]      FIG. 7  is a top plan view of the septum seal of the seal assembly of  FIG. 5 . 
           [0017]      FIG. 8  is a cross-sectional view of the septum seal of  FIG. 7 , taken along the lines VIII-VIII in  FIG. 7 . 
           [0018]      FIG. 9  is an enlarged section view of the proximal outer lip of the septum seal of  FIG. 8 . 
           [0019]      FIG. 10  is a top plan of the shield of the seal assembly of  FIG. 6 . 
           [0020]      FIG. 11  is a cross-sectional view of the shield of  FIG. 10 , taken along the line XI-XI in  FIG. 10 . 
           [0021]      FIG. 12  is a perspective view of a second embodiment of a shield of the seal assembly. 
           [0022]      FIG. 13  is a cross-sectional view of the shield of  FIG. 12 , taken along line XIII-XIII in  FIG. 12 . 
           [0023]      FIG. 14  is a perspective view of a third embodiment of a shield of the seal assembly. 
           [0024]      FIG. 15  is a cross-sectional view of the shield of  FIG. 14 , taken along line XV-XV in  FIG. 14 . 
           [0025]      FIG. 16  is a perspective view of a fourth embodiment of a shield of the seal assembly. 
           [0026]      FIG. 17  is a cross-sectional view of the shield of  FIG. 16 , taken along line XVII-XVII in  FIG. 16 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    Certain terminology will be used in this description for convenience and reference only, and will not be limiting. For example, the words “upwardly,” “downwardly,” “rightwardly,” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. The words “forwardly” and “distally” will refer to the direction toward the end of the arrangement which is closest to the patient, and the words “rearwardly” and “proximally” will refer to the direction toward the end of the arrangement which is furthest from the patient. This terminology will include the words specifically mentioned, derivatives thereof, and words of similar import. 
         [0028]    The preferred embodiment is a laparascopic trocar assembly  10  that includes a cannula assembly  12 , an obturator assembly  14 , and a laparoscope  16 , as shown in  FIG. 1 . 
         [0029]    The obturator assembly  14  preferably includes an obturator hub  18  which is connected to a tubular shaft  20  which has an optically clear tip  22  attached at its distal end. The shaft  20  is hollow, and made of a rigid metal, although it is contemplated that the shaft  20  could be made of other materials, and the hub  18  has an opening  24  which opens to a passageway through the hub  18  and which communicates with the interior of the shaft  20 . 
         [0030]    Accordingly, the laparoscope  16  may be inserted through the opening  24 , through the interior of the hub  18 , through the shaft  20 , and into the optically clear tip  22 . The hub includes a lock assembly  26  for locking the laparoscope  16  in place with respect to the obturator assembly  14  during use, and an engagement and disengagement system that includes hooks  28  which may engage with openings or grooves in a housing of the cannula assembly  12  to secure the obturator assembly  14  to the cannula assembly  12 . Pads  30  may be moved by pressing them inwardly to disengage the hooks  28  from the housing of the cannula assembly  12 . 
         [0031]    As shown in  FIGS. 1-4 , the cannula assembly generally includes a cannula  32 , a hub  34 , a seal housing  36 , and a gas valve  38 . The cannula  32  has a hollow interior  33  and extends along a longitudinal axis  35  (see  FIG. 4 ). 
         [0032]    Best seen in  FIG. 4 , the hub  34  is fixedly attached to the cannula  32  at an annular base  40  at the proximal end of the cannula  32 . The hub  34  includes a distal frustoconical section  42  and a cylindrical section  44  extending proximally from the frustoconical section  42 . The outer diameter of the cylindrical section  44  is less than the diameter of the proximal end of the frustoconical section  42  such that the housing  36  may be slid over the cylindrical section  44  to engage with the frustoconical section  42 . A portion of the valve  38 , which is preferably in the form of a stopcock but may be other configurations, is attached to the frustoconical section  42  and is preferably integrally formed therewith. Extending proximally from the outer edge of the frustoconical section  42  are two opposing hooks  46  (see  FIG. 2 ) for engagement with the housing  36 , which is described in more detail below. At least partially inside the hub  34  resides a lower seal  48 , preferably in the form of a duckbill valve. The lower seal  48  may be fixedly attached or removable from the hub  34 . The lower seal has a central opening  49 , which in the case of a duckbill valve, is a slit. 
         [0033]    As shown best in  FIGS. 2 and 4 , the seal housing has a substantially cylindrical outer wall  50  which depends from a cap  52 . The cap  52  is preferably affixed to, and may be integrally formed with, the cylindrical wall  50 . The cap  52  includes a central frustoconical-shaped port  54  for receiving a surgical instrument and urging the instrument toward the longitudinal axis  35  during entry of the instrument into the housing  36 . The port  54  includes a central opening  56  which allows entry of various-sized instruments into the housing  36  for entry into and through the cannula  32 . The port  54  of the cap  52  also includes a plurality of apertures  58 , in the form of slots, for receiving the engagement hooks  28  of the obturator assembly  14 . 
         [0034]    As part of the cylindrical wall  50  of the seal housing  36 , opposing latches  59  depend from an upper portion of the cylindrical wall  50 . Each latch  59  is slightly movable, but remains biased toward its initial position as part of the cylindrical wall  50 . Thus, when the housing  36  is moved over the cylindrical section  44  and into engagement with the frustoconical section  42  of the hub, the latches  59  engage with hooks  46  and are moved inwardly with respect to the rest of the cylindrical wall  50 . Because the latches  59  are created in such a manner to be biased toward their initial position, after passing a bulge part of the hooks  46 , each latch  59  moves slightly outwardly to engage a hook  46  and hold the housing in place with respect to the hub  34 . Pressing the latches  59  inwardly with respect to the remainder of the cylindrical wall  50  will move the latches past the innermost portion of bulge parts of the hooks  46  to allow removal of the seal housing  36  from the cannula hub  34 . 
         [0035]    At least partially within, and preferably entirely within, the housing  36  is an upper seal assembly  60 . The upper seal assembly  60  generally includes a septum seal  62  and a shield  64 . The upper seal assembly  60  is positioned proximally with respect to the opening  49  in the lower seal  48 . 
         [0036]    The shield  64  is seated within a portion of the septum seal  62  (see  FIG. 4 ). A seal retainer ring  66  engages with an inner portion of the housing  36  to hold the septum seal  62  and shield  64  in place with respect to the housing  36 . Adhesive or other means may be used to assist in affixing the upper seal assembly  60  to the housing  36 . As shown in  FIGS. 5-6 , the shield  64  is inserted into the septum seal  62 , which is in turn inserted and attached to the housing  36 . The seal retainer ring  66  is then inserted and attached to the housing to retain the upper seal assembly  60  in the housing  36 . 
         [0037]    The septum seal  62  is shown in detail in  FIGS. 7-9 . At its proximal end the septum seal  62  has an outwardly radially positioned outer lip  70 , which is described in more detail below. The outer lip  70  engages with the interior of the seal housing  36 , as shown in  FIG. 4 . A first seal wall  72 , in two portions, depends from the outer lip  70 . The first seal wall  72  includes an upper angled portion  74 , which defines a frustoconical portion, extending inwardly toward the longitudinal axis  35  as it extends downwardly from the outer lip  70 , as it is oriented in  FIG. 8 . The upper angled portion  74  is disposed at an angle A with respect to the longitudinal axis  35 , as shown in  FIG. 8 . Angle A is preferably between 40° and 50°, and more preferably about 45°. Depending from the upper angled portion  74  is a lower first wall portion  76 . The lower first wall portion  76  extends substantially parallel to the longitudinal axis  35  and thus is substantially cylindrical in nature. From the bottom of the lower first wall portion  76  extends a u-shaped bottom  78 . 
         [0038]    Extending upwardly from the bottom  78  is a second seal wall  80 , which is substantially parallel to the longitudinal axis  35 . A space  82  exists between the first wall portion  76  and the second seal wall  80 . The spacing and positioning of the first wall portion  76 , the bottom  78 , and the second seal wall  80  create a support member  81  which assists in supporting the structure of the septum seal  62  and assists in biasing an instrument inserted through the septum seal  62  toward the longitudinal axis  35 . Extending from the second wall  80  is a u-shaped upper portion  84 , and extending downwardly from the upper portion  84  is a third wall  86 . The third wall  86  is positioned inwardly with respect to second wall  80 , and the combination of the second wall  80 , the upper portion  84 , and the third wall  86  results in an inner ring  87 , which is spaced inwardly with respect to the first wall lower portion  76 . The walls  76 ,  80 ,  86  upper portion  84 , and bottom  78  together create an s-shaped structure which allows for off-axis entry and movement of instruments. 
         [0039]    To assist in stability, one or more ribs  88  are preferably used. Each rib  88  is attached to both the first wall lower portion  76  and the second wall  80 , and sits within the space  82  between those two walls. In a preferred embodiment, three equally spaced ribs are used, with each rib  88  being spaced 120° from another rib. However, more or less ribs may be used and/or different spacings may be employed. 
         [0040]    Extending inwardly from the third wall  86  is a sealing member  92 . The sealing member is substantially perpendicular to the longitudinal axis  35  and includes an outer narrow portion  94 , an inner ramp portion  96 , and an aperture  98 . The outer narrow portion  94  preferably extends about the entire circumferential distance of the sealing member  92  and extends from the third wall  86  inwardly to the inner ramp portion  96 , creating an annular groove  100 . The annular groove  100  is sized and shaped to receive a portion of the shield  64 . The structure of the lower portion of the septum seal  62  results in the third wall  86  and the sealing member  92  creating a substantially cylindrical space  102  with an upper open portion and a substantially closed bottom portion defined by the sealing member  92 . 
         [0041]    The outer lip  70  of the septum seal  62  has a fin shape with an upper member  104  and a lower member  106 , as shown in  FIG. 9 . A v-shaped notch  108  extends inwardly to define the upper member  104  and lower member  106 , and preferably has two substantially flat surfaces  110 ,  112 . The surfaces  110  and  112  are at an angle B with respect to one another, as shown in  FIG. 9 . Angle B may be any angle which results in a useful outer lip, but is preferably between 80° and 100°, and more preferably is about 90°. The outer lip  70  extends outwardly from the upper angled portion  74  of the first seal wall. A curved portion  114  attaches the upper angled portion  74  of the first seal wall  72  to the outer lip  70 . The radius of the curved portion  114  is designated as Y in  FIG. 9  and is sized and oriented such that the outer lip extends substantially perpendicularly to the longitudinal axis of the septum seal  62  and housing  36 . The radially inward portion of the outer lip  70  has a curved exterior which has a radius designated as Z in  FIG. 9 . Radius Z is preferably between 3 and 4 times that of radius Y, and more preferably is 3.5 times radius Y. 
         [0042]    Preferably, the septum seal  62  is monolithic and unitary, and made of a flexible material. More preferably, the septum seal  62  is made of an elastomer, and most preferably is made out of polyiosoprene. An additive, such as one of lubricating additives sold by Robin Industries, Inc. Of Independence, Ohio particularly model numbers IE-131001, IE-131003, and IE-131004, may be mixed with the polyiosoprene to increase the lubricity of the seal  62 . In addition, the septum seal  62  may be chlorinated using a gaseous chlorine method. Preferably the septum seal  62  chlorination level of between about 600 ppm and about 1200 ppm. Also, the material used for the septum seal  62  preferably has a durometer hardness of between 30 and 35 shore A. The thickness of walls  76 ,  80 , and  86  is preferably on the order of 0.010 inches±0.002 inches, and the overall thicknesses of the seal range between 0.007″ and 0.035″. 
         [0043]      FIGS. 10-11  show the shield  64  in more detail. 
         [0044]    The shield  64  is generally cylindrical in shape and is a unitary, monolithic structure preferably made of a polyether-based thermoplastic polyurethane. An example of such a polyurethane is Texin®, grade Rxt85A, sold by Bayer MaterialScience headquartered in Leverkusun, Germany. The material preferably has a durometer hardness of between 80 shore A and 90 shore A, and more preferably about 85 shore A. 
         [0045]    The shield  64  has multiple indented members  116 . Each indented member  116  extends radially inwardly from an outer base  118  of the shield to an inner aperture  120 , which is centrally located and when in use is aligned with the longitudinal axis  35 . Inner aperture  120  preferably has a width (for example, diameter) less than that of the aperture  98  of the septum seal  62 , resulting in the prevention of tearing or catching of the septum seal  62  by an instrument that is inserted at an angle off of the longitudinal axis. 
         [0046]    Each indented member  116  takes up an equal space and is equally sized and shaped as the other indented members  116 . Each indented member  116  includes an indent  122  which extends from an uppermost position at the outer base  118  downwardly toward the inner aperture  120  to its lower most position. Thus, together, the indents  122  create a series of folded members  124  about the inner aperture  120 . Also, due to the nature of the indents  122 , a series of radially-extending ridges  126  are created, each of which defines an outer circumferential boundary of an indented member  116 . The ridges  126  are each spaced an angle C from one another, and in the embodiment shown in  FIG. 10 , are equally spaced, making C equal to 60°. 
         [0047]    The outer base  118  has an upper area  128  with a first outer diameter and a lower area  130  with a second outer diameter, as shown in  FIG. 11 . As shown, the outer diameter of the lower area  130  is greater than the outer diameter of the upper area  128 , creating a shoulder  132  between the upper area  128  and the lower area  130 . The respective inner diameters of the upper area  128  and the lower area  130  are the same, thus resulting in a thickness of the lower area  130  being greater than that of the upper area  128 . The thickness of the lower area  130  is such that the shield  64  may be seated within the annular groove  100  of the sealing member  92  of the septum seal  62 , while maintaining stability of the shield  64 . The thinner upper area  128  allows for a degree of flexibility of the shield  64 . The thickness of the material of the shield  64  in the area of the centrally-located folded members is between 0.007″ and 0.020″, and more preferably is about 0.014″. 
         [0048]    The reference numeral  64   a  ( FIGS. 12-13 ) generally designates another embodiment of the shield of the present invention. Since the shield  64   a  is similar to the previously described shield  64 , similar parts appearing in FIGS.  6  and  10 - 11  are represented by the same, corresponding reference number, except for the suffix “a” in the numerals of the latter. The shield  64   a  is essentially identical to the shield  64 , except that the shield  64   a  has an upper area  128   a  which includes an upwardly extending upper wall portion  134  that extends above the inner portion of the shield  64   a , generally defined by the indented members  116   a  and ridges  126   a . The upper wall portion  134  has a tapered top  136 . The shape and structure of the upper wall portion  134  provides additional protection of the septum seal  62  from aggressive instruments. 
         [0049]    The reference numeral  64   b  ( FIGS. 14-15 ) generally designates yet another embodiment of the shield of the present invention. Since the shield  64   b  is similar to the previously described shield  64 , similar parts appearing in FIGS.  6  and  10 - 11  are represented by the same, corresponding reference number, except for the suffix “b” in the numerals of the latter. The shield  64   b  is essentially identical to shield  64 , with the exception that the shield  64   b  includes an angled upper wall portion  138  which extends outwardly. The upper wall portion  138  increases in diameter moving upwardly, as shown and oriented in  FIG. 15 . The upper wall portion  138  is at an angle D with respect to the horizontal, and angle D is preferably between 40° and 50°, and more preferably 45°. The upper wall portion  138  is configured for engagement with the underside of the port  54  and acts as additional protection to the septum seal  62  from aggressive instruments. 
         [0050]    The reference numeral  64   c  ( FIGS. 16-17 ) generally designates still another embodiment of the shield of the present invention. Since the shield  64   c  is similar to the previously described shield  64 , similar parts appearing in FIGS.  6  and  10 - 11  are represented by the same, corresponding reference number, except for the suffix “c” in the numerals of the latter. The shield  64   c  is essentially identical in all respects to the shield  64 , except that the indented members  116   c  taper toward the bottom of the shield  64   c , as oriented and shown in  FIG. 17 , moving toward the center hole  120   c . Thus, this configuration results in the top of the shield  64   c  having a conical or frusta-conical shape. This shield configuration acts as an extra measure to protect the septum seal  62  from aggressive instruments, while the conical profile of the shield  64   c  guides instruments toward the inner aperture  120   c  and thus toward the septum aperture  98 . 
         [0051]    In operation, the obturator assembly  14  is inserted, tip  22  first, into the port  54  of the housing  36 . The tip  22  is extended through the opening  56  in the port  54 , into and through the inner aperture  120  of the shield  64 , into and through the aperture  98  of the septum seal  62 , beyond the lower end of the housing and through the opening  49  in the lower seal  48 . The tip  22  may then be extended into and through the interior  33  of the cannula  32  with the tip  22  extending beyond the distal edge of the cannula  32 . The obturator assembly  14  is extended until the obturator hub  18  engages with the cap  52  of the housing  36 . The obturator hub  18  is preferably aligned such that the hooks  28  engage with the slots  58  in the cap  52 , temporarily affixing the obturator assembly  14  to the cannula assembly  12 . 
         [0052]    The laparoscope  16  may then be inserted into the obturator assembly  14 . The laparoscope  16  is inserted through the opening  24  of the hub  18 , through the hub  18 , through the shaft  20 , and adjacent to or into the optically clear tip  22 . Once the laparoscope  16  is in the desired position, the locking mechanism  26  may be engaged to temporarily lock the laparoscope  16  in place with respect to the obturator assembly  14 . Alternatively, a bladed obturator or other instrument may be inserted into and, extend out of, the cannula assembly  12 . 
         [0053]    Once the surgical procedure is complete, and/or the laparoscope  16  or obturator assembly  14  is no longer needed for the surgical procedure, the locking mechanism  26  may be disengaged, allowing the laparoscope  16  to be removed from the obturator assembly  14 . The pads  30  of the hub  18  of the obturator assembly  14  may then be engaged to move the hooks  28  inwardly to allow disengagement of the hooks  28  from the slots  58  of the cap  52  of the housing  36 . The obturator assembly  14  can then be removed from the cannula assembly  12 . 
         [0054]    During the surgical procedure, the stopcock valve  38  may be used to allow insufflation gas or to disallow insufflation gas into the surgical area. The lower seal  48  and septum seal  62  allow the retention of insufflation gas in the surgical site area while the obturator assembly  14  or other surgical instrument is inserted into and through the cannula assembly  12 . 
         [0055]    Even if the obturator assembly  14  or other surgical instrument is inserted into the cannula assembly  12  in a direction other than along the longitudinal axis  35 , the combination of the port  54 , the shield  64 , and the septum seal  62  will result in adjustment of the position and/or angle of the instrument to result in the instrument being positioned substantially along the longitudinal axis  35 . The structure and flexibility of the septum seal  62  and shield  64  result in an effective means by which a surgical instrument can be inserted in many different orientations into the cannula assembly  12 , and directed through the interior  33  of the cannula  32  without tearing or breaking the seal assembly  60 . 
         [0056]    Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.