Patent Publication Number: US-2018035995-A1

Title: Instrument access device

Description:
INTRODUCTION 
     Accessing the abdominal cavity while preserving the abdominal wall as much as possible is the aim of any surgical or exploratory procedure. Retraction devices have been used to this end. A retractor can help to expose an operative site and minimise the incision required to carry out the operation. 
     Minimally invasive surgery is an evolving surgical method that similarly attempts to reduce the size of incisions required, in many cases dramatically. By using a so-called “keyhole” or cannula, the surgeon can gain access with instruments into the abdominal cavity to carry out an operation through a very small series of holes in the abdominal wall. Unlike in the case of “open surgery”, primary retraction then must be accomplished by lifting the abdominal wall away from the abdominal viscera. This is most often accomplished with the use of gas in a technique known as insufflation. 
     The use of a cannula to gain access as a means to see inside the abdomen or introduce surgical instruments has existed since the late 19 th  century. A cannula comprises a rigid tube, which is inserted through the abdominal wall and is held in place by the tension of the abdominal wall itself around the inserted cannula. The tube must accommodate various thicknesses of abdominal wall and extend significantly both inside and outside the abdomen to avoid slipping out of the incision, and thereby causing gas pressure to escape. 
     The basic construction of a cannula, however, presents significant limitations in carrying out a surgical procedure. Some of these limitations are as follows.
         1. A cannula is held in place, and thus prevents the escape of gas, by tissue tension. This tension can vary depending on the way the cannula is introduced or weaken during the operation under normal surgical manipulation.   2. A cannula extends significantly into the abdominal cavity taking up precious space and interfering with other instruments.   3. A cannula restricts the movement of instruments as they are rigid structures.   4. A rigid cannula presents significant limitations on the design of the instrument which must be passed through the cannula.   5. A cannula takes up a significant space outside of the abdomen, shortening the effective length, and therefore reach, of the surgical instrument.       

     This invention is directed towards providing an instrument access device which will address at least some of these problems. 
     STATEMENTS OF INVENTION 
     According to the invention there is provided an instrument access device comprising:
         a distal anchoring member for insertion into a wound interior;   an elongate member extending proximally from the distal anchoring member to retract laterally the sides of a wound opening; and   an instrument working channel through which an instrument may extend to access the wound interior.       

     In one embodiment of the invention the device comprises a proximal member for location externally of a wound opening. The proximal member may comprise a ring member. The proximal member may comprise a proximal inner element and a proximal outer element. The elongate member may be led between the proximal inner element and the proximal outer element. The proximal inner element and/or the proximal outer element may comprise a ring element. The proximal outer element may be mounted to the proximal inner element. The proximal outer element may be demountable from the proximal inner element. 
     In one case the proximal outer element comprises an engagement surface for resting upon the proximal inner element to mount the proximal outer element to the proximal inner element. The engagement surface may comprise a curved surface. The engagement surface may extend in cross-section for substantially a quarter-revolution. The engagement surface may be configured to engage a proximal side of the proximal inner element. 
     In another case the device comprises a clamp for clamping the instrument working channel in position. The clamp may be configured to clamp the elongate member to the instrument working channel. The clamp may comprise a proximal clamp. The clamp may be defined by the proximal outer element and the proximal inner element. The proximal outer element may comprise a proximal outer ring. The proximal inner element may comprise a proximal inner ring. The proximal inner element may be defined by a portion of the instrument working channel. 
     In another embodiment the device comprises at least one instrument seal or valve. The seal or valve may comprise a gelatinous elastomeric material. The seal or valve may comprise at least one opening extending therethrough through which an instrument may be extended. The opening may be biased towards a closed configuration. The opening may comprise a pinhole opening. 
     In one case the seal or valve is piercable to create at least one opening extending therethrough through which an instrument may be extended. The seal or valve may be piercable by an instrument to create an opening extending therethrough. 
     In another case the seal or valve comprises an insufflation lumen extending therethrough. The longitudinal axis of the insufflation lumen may be substantially parallel to the longitudinal axis of the device. 
     In another embodiment the device comprises a housing for an instrument seal or valve. The housing may comprise a reception space for receiving an instrument seal or valve. The reception space may have an inlet through which an instrument seal or valve may be located in the reception space. The inlet may face proximally. 
     In one case the housing comprises a retainer to retain an instrument seal or valve in the reception space. The retainer may comprise a cap for at least partially closing the inlet. The retainer may comprise an opening to facilitate access to an instrument seal or valve in the reception space. The retainer may be substantially annular in shape. 
     In another case the housing comprises a locator to assist in locating a seal or valve in the reception space. The locator may comprise at least one male member for co-operative association with at least one corresponding female member. 
     In one embodiment the housing comprises an insufflation lumen extending therethrough. The longitudinal axis of the insufflation lumen may be substantially parallel to the longitudinal axis of the device. The housing insufflation lumen may be aligned with an insufflation lumen of an instrument seal or valve. The device may comprise an insufflation seal or valve for the insufflation lumen. The insufflation seal or valve may be provided at a proximal end of the insufflation lumen. The insufflation seal or valve may be pierceable by an insufflation tube. 
     In one case the access device comprises an intermediate connector to connect the insufflation lumen in communication with an insufflation tube. The intermediate connector may be configured to connect an insufflation tube in communication with the insufflation lumen with the longitudinal axis of the insufflation tube at a distal end of the insufflation tube inclined relative to the longitudinal axis of the insufflation lumen. The intermediate connector may be configured to connect an insufflation tube in communication with the insufflation lumen with the longitudinal axis of the insufflation tube at a distal end of the insufflation tube substantially perpendicular to the longitudinal axis of the insufflation lumen. 
     In a further case the housing is mounted to the proximal member. The housing may be mounted to the proximal inner element. The housing may extend distally of the proximal inner element. The housing may be located radially inwardly of the proximal inner element. The housing may be demountable from the proximal inner element. 
     In one case the device comprises a seal across the proximal inner element. The seal may be piercable by the housing and/or by the instrument working channel upon mounting of the housing to the proximal inner element. 
     In a further embodiment the housing is formed integrally with the proximal inner element. 
     The housing may define the proximal inner element. 
     In one case the device comprises a sleeve extending from the proximal inner element to the housing. The sleeve may be formed integrally with the elongate member. 
     In one embodiment the housing at least in part defines the instrument working channel. The instrument working channel may be mounted to the housing. The instrument working channel may be demountable from the housing. In one case the instrument working channel is formed integrally with the housing. 
     In one embodiment the instrument working channel is defined by a tubular member. The tubular member may be substantially rigid over at least part of its length. The tubular member may define a lumen extending therethrough through which an instrument may be extended. The tubular member may have a distal opening at a distal end of the tubular member. The distal opening may be inclined relative to the longitudinal axis of the tubular member. The plane of the distal opening may be inclined relative to the longitudinal axis of the tubular member. The tubular member may have a low-profile leading end. The leading end may be tapered. The leading end may be tapered to a point. The distal end of the tubular member may be skived. 
     In another embodiment the instrument working channel is mounted to the proximal member. The instrument working channel may be mounted for controlled movement relative to the proximal member. The device may comprise a sleeve extending between the instrument working channel and the proximal member to mount the instrument working channel to the proximal member. 
     In one case the elongate member comprises a sleeve. At least a portion of the sleeve may comprise two material layers. The sleeve may be wrapped around the distal anchoring member. The sleeve may be slidably movable relative to the distal anchoring member. The sleeve may comprise a single material layer. An end of the sleeve may be fixed to the distal anchoring member. 
     In a further case the elongate member extends from the distal anchoring member to at least the proximal member. The elongate member may be slidably movable over at least a portion of the proximal member. The elongate member may be slidably movable over the proximal inner element. An end of the elongate member may be fixed to the proximal member. An end of the elongate member may be fixed to the housing. The elongate member may be fixed to the proximal member at one end, the elongate member may extend from the proximal member to the distal anchoring member to define an inner material layer, and the elongate member may extend from the distal ring anchoring member to the proximal member to define an outer material layer. 
     In one case the distal anchoring member comprises a distal ring. The distal ring may be formed from an elastomeric material. 
     The device may comprise at least one proximal handle for manipulating the device, in situ. 
     In another aspect of the invention there is provided an instrument access device comprising:
         a distal ring;   a proximal ring;   a sleeve having a portion between the distal ring and the proximal ring that includes two material layers; and   an instrument seal or valve mounted to the proximal ring.       

     In one embodiment the sleeve is fixed to the proximal ring at one end, the sleeve extends from the proximal ring to the distal ring to define an inner material layer, and the sleeve extends from the distal ring to the proximal ring to define an outer material layer. The sleeve may be slidingly received over a portion of the proximal ring. 
     In one case the proximal ring comprises an inner proximal ring member and an outer proximal ring member between which the sleeve is led. 
     The instrument also provides in another aspect an instrument access device comprising:
         a distal ring;   a proximal ring;   a sleeve having a portion between the distal ring and the proximal ring; and   an instrument seal or valve comprising a gelatinous elastomeric material for receiving an instrument.       

     The gelatinous elastomeric material may have a pinhole to receive an instrument. 
     In a further aspect, the invention provides an instrument access device comprising:
         a distal anchoring member for insertion into a wound interior;   a proximal member for location externally of a wound opening;   a sleeve extending in two layers at least between the distal anchoring member and the proximal member; and   an instrument seal or valve comprising a gelatinous elastomeric material for receiving an instrument.       

     The invention also provides in another aspect an instrument access device comprising:
         a distal anchoring member for insertion into a wound interior;   a proximal member for location externally of a wound opening;   an elongate member extending at least between the distal anchoring member and the proximal member;   the proximal member comprising a proximal inner element and a proximal outer element between which the elongate member is led; and   an instrument seal or valve mounted to the proximal inner element.       

     According to another aspect of the invention there is provided a method of accessing a wound interior with an instrument, the method comprising the steps of:
         inserting a distal anchoring member through an incision, the distal anchoring member having an elongate member attached thereto;   presenting an instrument working channel member to the incision;   pulling the elongate member upwardly relative to the instrument working channel member to at least partially insert the instrument working channel member into the incision; and   inserting an instrument through the incision.       

     In one embodiment the elongate member lies at least in part between the instrument working channel member and the walls of the incision. 
     In one case the incision is a laparoscopic incision. The sides of the incision may be retracted to a diameter of less than 40 mm. The sides of the incision may be retracted to a diameter of between 3 mm and 35 mm. The sides of the incision may be retracted to a diameter of between 5 mm and 12 mm. 
     In another case the sides of the incision are retracted to a diameter substantially equal to a diameter of the instrument working channel member. 
     The sides of the incision may be at least partially retracted by insertion of the instrument working channel member into the incision. The sides of the incision may be at least partially retracted by pulling of the elongate member upwardly relative to the instrument working channel member. 
     In one case the instrument is a laparoscopic instrument. The instrument may have a diameter of less than 40 mm. The instrument may have a diameter of between 3 mm and 35 mm. The instrument may have a diameter of between 5 mm and 12 mm. 
     In one case after insertion of the instrument working channel member into the incision, the distal end of the instrument working channel member is located within the wound interior distally of the incision. In another case after insertion of the instrument working channel member into the incision, the distal end of the instrument working channel member is located within the incision proximally of the wound interior. 
     In one embodiment the leading end of the instrument working channel member is guided into the incision. The instrument working channel member may be configured to automatically guide the leading end into the incision. 
     The method may comprise the step of sealing the incision. The method may comprise the steps of insufflating the wound interior. The wound interior may be insufflated after insertion of the instrument working channel member into the incision. 
     In another aspect the invention provides a method of retracting a wound opening, the method comprising the steps of:
         inserting a distal anchoring member through a wound opening into a wound interior;   locating a proximal member externally of the wound opening with an elongate member extending at least between the distal anchoring member and the proximal member;   locating a guide member externally of the wound opening;   moving the guide member and the proximal member relative to the elongate member to retract laterally the sides of the wound opening; and   removing the guide member while the distal anchoring member, the proximal member and the elongate member remain in position retracting the wound opening.       

     In one case the elongate member is led between the proximal member and the guide member. 
     The elongate member may extend in two layers between the proximal member and the distal anchoring member. 
     In another case the proximal member is moved by pushing the guide member which engages the proximal member. 
     The invention also provides in a further aspect a method of retracting a wound opening, the method comprising the steps of:
         inserting a distal anchoring member through a wound opening into a wound interior;   locating a proximal member externally of the wound opening with an elongate member extending at least between the distal anchoring member and the proximal member;   moving the proximal member relative to the elongate member to retract laterally the sides of the wound opening; and   mounting a first seal or valve to the proximal member.       

     In one embodiment the first seal or valve is mounted to the proximal member after retraction of the wound opening. The first seal or valve may be mounted to the proximal member before retraction of the wound opening. 
     In one case the method comprises the step of piercing a second seal. The second seal may be pierced upon mounting of the first seal or valve to the proximal member. 
     In a further aspect of the invention there is provided a method of retracting a wound opening, the method comprising the steps of:
         inserting a distal anchoring member through a wound opening into a wound interior;   locating a proximal member externally of the wound opening with an elongate member extending at least between the distal anchoring member and the proximal member; and   by means of a single actuation step, moving the proximal member relative to the elongate member to retract laterally the sides of the wound opening.       

     In one embodiment the entire circumference of the proximal member is moved together relative to the entire circumference of the elongate member. 
     The proximal member may be pushed distally relative to the elongate member. The elongate member may be pulled proximally relative to the proximal member. The proximal member may be moved relative to the elongate member in a single direction. The proximal member may be moved relative to the elongate member in a direction substantially parallel to the longitudinal axis of the wound opening. 
     In one case the method comprises the step of gripping the proximal member. The proximal member may be gripped by a single hand of a user. Opposite sides of the proximal member may be gripped by a single hand of a user. The method may comprise the step of gripping the elongate member. The elongate member may be gripped by a single hand of a user. The entire circumference of the elongate member may be gripped by a single hand of a user. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:
           FIG. 1  is a perspective view of a liner part of an instrument access device of the invention;     FIG. 2  is a cross sectional, side view of the liner part of  FIG. 1  inserted in an incision;     FIG. 3  is a perspective view of a tubular member defining an instrument working channel of the access device;     FIG. 4  is a cross sectional, side view of the access device in place in an incision;     FIG. 5  is a cross-sectional, side view similar to  FIG. 4  illustrating clamping or anchoring of the tubular member;     FIGS. 6 and 7  are views similar to  FIGS. 1 and 2  of an alternative liner part with a proximal valve or seal;     FIGS. 8 and 9  are views similar to  FIGS. 4 and 5  with the liner part of  FIGS. 6 and 7 , in use;     FIGS. 10 and 11  are views similar to  FIGS. 4 and 5  of an alternative tubular member with a proximal valve or seal, in use;     FIG. 12  is a cross sectional, side view of an instrument access device of the invention; in use;     FIG. 13  is a cross sectional, side view of another instrument access device of the invention, in use;     FIGS. 14 to 16  are cross sectional, side views of a further instrument access device of the invention, in use;     FIGS. 17 to 19  are cross sectional, side views of alternative instrument access devices of the invention, with different tubular members;     FIG. 20  is a perspective view of one of the tubular members of  FIGS. 17 to 19 ;       

         FIG. 21  is a cross sectional, perspective view of the tubular member of  FIG. 20 ;
           FIG. 22  is a perspective view of a housing part of the access device of the invention;     FIG. 23  is a cross sectional, perspective view of the housing part of  FIG. 22 ;     FIGS. 24 and 25  are exploded, perspective views of an outer proximal ring and housing part assembly of the access device of the invention;     FIGS. 26 to 28  are cross sectional, side views of another instrument access device of the invention, in use;     FIGS. 29 and 30  are cross sectional, side views of a further instrument access device of the invention, in use;     FIGS. 31 and 32  are cross sectional, side views of another instrument access device of the invention;     FIGS. 33 to 37  are cross-sectional, side views of a further instrument access device of the invention;     FIGS. 38 and 39  are cross sectional, side views of a still further instrument access device of the invention;     FIGS. 40 to 42  are cross sectional, side views of another instrument access device of the invention;     FIG. 43  is a cross sectional, side view of a further instrument access device of the invention;     FIGS. 44 to 46  are cross sectional, side views of another instrument access device of the invention;     FIGS. 47 to 49  are cross sectional, side views of a further instrument access device of the invention;     FIGS. 50 to 55  are views of another instrument access device of the invention;     FIGS. 56 to 58  are cross sectional, side views of a further instrument access device of the invention;     FIG. 58( a )( i )  is a cut-away, perspective view of another instrument access device according to the invention;     FIG. 58( a ) ( ii ) is an exploded, perspective view of a part of the device of  FIG. 58( a )( i ) ;     FIG. 58( b )  is an assembled, perspective view of the part of the instrument access device of  FIG. 58( a ) ( ii );     FIG. 58( c )( i )  is a cut-away, perspective view of the part of the instrument access device of  FIG. 58  (a)(ii);     FIGS. 58( c ) ( ii ) and  58 ( c )( iii ) are cross-sectional, side views of the device of  FIG. 58( a )( i ) , in use;     FIGS. 58( d ) and 58( e )  are views similar to  FIGS. 58( a ) ( ii ) and  58 ( c )( i ) of part of another instrument access device according to the invention;     FIGS. 58( f ) and 58( g )  are partially cross-sectional, side views of another instrument access device according to the invention, in use;     FIGS. 58( h ) and 58( i )  are partially cross-sectional, side views of a further instrument access device according to the invention, in use;     FIGS. 59 to 61  are cross sectional, side views of another instrument access device of the invention;     FIGS. 62 to 64  are cross sectional, side views of a further instrument access device of the invention;     FIG. 65  is a cross sectional, side view of another instrument access device according to the invention;     FIG. 66  is a cut-away, perspective view of a part of the device of  FIG. 65 ;  FIG. 67  is an end view of the part of  FIG. 66 ;     FIGS. 68 to 70  are cross-sectional, side views of the device of  FIG. 65 , in use;     FIGS. 70( a ) to 70( f )  are cross-sectional, side views of another instrument access device according to the invention, in use;     FIGS. 70( g ) to 70( i )  are cross-sectional, side views of another instrument access device according to the invention, in use; and     FIGS. 71 to 73  are cross-sectional, side views of a further instrument access device according to the invention, in use.       

     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings there are illustrated various instrument access devices of the invention for an incision  1 , for example in an abdominal wall  2 . The construction of the various components and their attributes will be explained in detail below. In some cases, the instrument access device is used as a substitute for a conventional rigid tubular cannula. The instrument access devices of the invention may be used to provide access to the abdominal cavity by an instrument  3 , which in this case has an operating element  4 , such as a surgical stapler, mounted at the distal end of a flexible shaft  5 . 
     It will be noted that the devices have a very low profile, especially with respect to the inside of the incision  1 . The devices are positively retained in the incision  1  against pull-out forces. Because of the low profile the shaft  5  of the instrument  3  can begin bending immediately after entering the abdominal cavity. The amount of free space required to manipulate the instrument  3  is minimised. This is in contrast to a conventional cannula, in which the rigid tube of the cannula must be extended significantly into the abdomen to ensure that it remains anchored in the abdomen, otherwise gas pressure may cause it to become dislodged. In conventional systems, because of the cannula length extending into the abdomen, the shaft  5  of the instrument  3  cannot be steered until the steerable section has exited the cannula. Thus, there are severe limitations on the use of such instruments using a conventional cannula. These problems are overcome at least in part using the instrument access devices of the invention. 
     Referring initially to  FIGS. 1 and 2  there is illustrated a liner part  10  of the access device. The liner part  10  comprises a distal anchoring member  11  and an elongate member  12  extending proximally of the distal anchoring member  11 . 
     In this case, the elongate member is provided in the form of a sleeve  12  of flexible, polymeric film material which lines the sides of the wound opening  13 , in use. The distal anchoring member  11  in this case comprises a resilient O-ring. 
     An instrument working channel is in this case defined by a tubular member  15  which may be substantially rigid along at least portion of the length thereof. 
     In use, a relatively small incision  1  is made in an abdominal wall  2  to form the wound opening  13 . A typical length for the incision  1  is in the range of from 12 mm to 30 mm. The resilient distal O-ring  11  is then manipulated into an elongate, oblong shape by squeezing the distal O-ring  11  to facilitate insertion of the distal O-ring  11  through the wound opening  13 , until the distal O-ring  11  is fully located within the abdominal cavity and the sleeve  12  lines the wound opening  13 . The tubular member  15  is then presented to the wound opening  13  inside the sleeve  12 . The sleeve  12  is then pulled upwardly relative to the tubular member  15  to cause the tubular member  15  to enter the wound opening  13  and to cause the distal O-ring  11  to engage with the internal surface of the abdominal wall. 
     The tubular member  15  is clamped or anchored to the sleeve  12  by a suitable clamp such as a proximal clamp  17 . 
     The use of the tubular member  15  provides an enhanced instrument working channel through the wound opening  13 . It assists in preventing collapse of the sides of the wound opening  13 . There is less friction as the instrument  3  is inserted and manipulated. Importantly, the tubular member  15  assists in providing a device that has a very low profile with the consequent advantages of maximising the surgeon&#39;s freedom of movement. 
     Any suitable valve or seal or combinations of valves and/or seals may be provided for an instrument. Such valve or valves are generically indicated by an X and by the reference numeral  20  in the drawings. In one arrangement ( FIGS. 6 to 9 ) a valve  20  is provided at a proximal end of the sleeve  12 . In another arrangement a valve  20  is provided at a proximal end of the tubular member  15  ( FIGS. 10 and 11 ). Indeed valves  20  may be provided both on the sleeve  2  and on the tubular member  15 . 
     The sleeve  12  may be a single layer sleeve or may have two layers at least in the section which lines the wound opening  13 . One such arrangement is illustrated in  FIG. 12  in which the sleeve  12  is wrapped around the distal ring  11  and has an outer layer  22  which lines the wound opening  13  and an inner layer  23 . A clamp is in this case a proximal clamp comprising an outer proximal ring member  24  and an inner proximal ring member  25  between which the sleeve  12  extends. In this case the inner proximal clamp is mounted to or provided by part of a housing  27  for a valve  20 . The sleeve  12  is mounted at one end to the ring member  25  or housing  27  and extends to form the inner layer  23 , is wrapped around the distal ring  11  and extends to form the outer layer  22 . The sleeve  12  is slidable on at least portion of the inner proximal clamp ring  25  and the sleeve  12  is slidable relative to the distal ring  11 .. On pulling of the sleeve  12  upwardly the wound opening  13  is retracted. Because of the sleeve pathway a free end of the sleeve  12  is external of the valve  20  and can be readily removed, if desired. In this case the proximal ring member  25  is formed integrally with the housing  27 . 
     Referring now to  FIGS. 13 to 16  there is illustrated an instrument access device having a valve housing  27  and an instrument working channel defined by a tubular member or stub  40  which extends into the wound opening  13  from the valve housing  27 . The tubular member  40  need not necessarily extend fully into the wound opening. In the arrangement of  FIG. 13  it is shown extending only partially through the wound opening whilst in  FIGS. 14 to 16  the tubular member  40  extends fully the thickness of the abdomen. The valve housing  27  in this case also has an insufflation port  42 . In this case the tubular member  40  is formed integrally with the housing  27 . 
     The tubular member  40  may be detachably mounted to the valve housing  27  as illustrated particularly in  FIGS. 17 to 25 . In this way the access device may be adapted for different situations such as different sized abdomens or depending on the degree of access required by the surgeon. The tubular members  40  may be of varying lengths, as illustrated. Any suitable mounting may be provided between the tubular member  40  and the valve housing  27  such as adhesive, an interference fit, a spigot and socket, screw threaded, or bayonet type fitting. 
     Referring to  FIGS. 24 and 25  the outer proximal clamp ring member may be split into sections  24   a ,  24   b  for ease of assembly, disassembly. The ring sections  24   a ,  24   b  can be assembled and fixed using any suitable means such as adhesive or the like. 
     Referring to  FIGS. 26 to 28  there is illustrated a further instrument access device according to the invention. In this case a seal in the form of a sheet  50  of film material is extended across the inner proximal ring  25  to maintain pneumoperitoneum. The tubular member  40  has a tapered distal end  55  for ease of breaking through the film  50  as illustrated in  FIG. 27 . The valve housing  27  in this case is configured at  56  to snap fit over an outer proximal ring  24  for assembly of the valve housing  27  to the retractor base. The access device is illustrated in use in  FIG. 28 . 
     Referring to  FIGS. 29 and 30  the access device in this case has a gripper or handle provided by an anchor eye  57  and a lifting wire  58 . On pulling of the lifting wire  58  upwardly as indicated by the arrow in  FIG. 30  the device can be easily tilted providing easier access to more areas of the abdomen. The force on the lifting wire  58  can be varied to increase or decrease the angle alpha to provide further desired access. 
     Referring to  FIGS. 31 and 32  there is illustrated another instrument access device which is similar to those described above and like parts are assigned the same reference numerals. In this case the tubular member  40  is detachable and a suitable tubular member  40  is attached to the valve housing  27  prior to deployment in a patient. 
     Referring to  FIGS. 33 to 37  there is illustrated the method of using a device such as the device of  FIGS. 31 and 32 . The surgeon first selects the detachable tubular member  40  of desired length, for example based on the abdominal wall thickness. The tubular member  40  is attached ( FIG. 34 ) so that the device is ready for deployment. The distal ring  11  is deployed in the abdomen as described above. The sleeve  12  is pulled upwardly in the direction of the arrow A whilst pushing down on the proximal ring  24  in the direction of the arrow B. Retraction of the incision  1  commences and the tubular member  40  begins to enter the margin of the incision  1  ( FIG. 36 ). As the pulling and pushing action is continued the tubular member  40  is fully deployed creating an instrument working channel in the wound opening  13  ( FIG. 37 ). The device is extremely low profile, easy to deploy, and creates an excellent working channel which provides maximum flexibility in instrument manipulation. 
     Referring to  FIGS. 38 and 39  there is illustrated another instrument access device which is similar to those described above and like parts are assigned the same reference numerals. In this case the valve housing  27  is connected to the inner proximal ring  25  by a suitable connection such as a flexible sleeve or corrugated tube  60 . In use, the tubular member  40  is flexible relative to the proximal anchor which may be beneficial in reducing drag/friction. 
     Another access device of the invention is illustrated in  FIG. 40 . In this case, the free end of the sleeve  12  is external of a valve such as a lipseal valve  70  which is connected to the inner proximal ring  25  by means of a flexible connecting sleeve  75 . 
     The retractor is easily deployed as the free end of the sleeve  12  which is pulled on for deployment is readily accessible. The operation of this device is illustrated in  FIGS. 41 and 42 . It will be noted that in view of the flexible connection  75  tilting of the instrument does not cause a leak path. This arrangement may be used with any suitable valve(s) and/or seal(s)  20 , as illustrated in  FIG. 43 . 
     Another access device similar to that of  FIGS. 40 to 42  is illustrated in  FIGS. 44 to 46 . In this case the flexible connection is provided by a corrugated tube  80 . 
     A further access device of the invention is illustrated in  FIGS. 47 to 49 . It will be noted that in this case a proximal inner ring  85  is undersized with respect to the receiver of an outer proximal ring  86 . As illustrated in  FIG. 49  when the instrument  3  is tilted off its vertical axis, the valve housing  27  can move due to this clearance without compromising the seal between the lipseal  70  and the instrument  3 . Thus, off-axis movement is accommodated without compromising the seal to the instrument  3 . 
     Referring to  FIGS. 50 to 55  a self locking retractor of the type described above has a valve/seal provided by a body of gelatinous elastomeric material  90  which in this case is simply illustrated as extending across the inner proximal ring  25 . The gelatinous elastomeric body  90  may have a pin hole  91  for ease of insertion of an instrument  3 . The gel  90  deforms as the instrument  3  is inserted. If there is a pre-made pinhole  91 , this facilitates entry. If there is no pinhole, the leading edge of the instrument  3  will eventually pierce the material. In use the gel  90  seals around the instrument shaft  5 . Upon withdrawal of the instrument  3 , the hole  91  in the gel  90  self-seals closed. 
       FIGS. 56 to 58  illustrate the use of a gelatinous elastomeric seal/valve  95  as described above with reference to  FIGS. 50 to 55  with a valve housing  96  of the type described above. 
     Referring to  FIGS. 58( a )( i ) to 58( c ) ( iii ) there is illustrated another instrument access device  500  according to the invention, which is similar to the instrument access device of  FIGS. 56 to 58 , and similar elements in  FIGS. 58( a )( i ) to 58( c ) ( iii ) are assigned the same reference numerals. 
     In this case the seal/valve housing of the device  500  comprises a housing body  300  and a housing cap  301 . 
     The housing body  300  comprises a reception space  305  for receiving the gelatinous elastomeric seal  302  with the pinhole opening  303  extending therethrough. As illustrated in  FIG. 58( a ) ( ii ), the reception space  305  has an open proximal end which acts as an inlet through which the seal  302  may be located in the reception space  305 . The housing body  300  comprises a plurality of upstanding male pins  304  which may be co-operatively associated with corresponding female openings  306  in the seal  302  to control location of the seal  302  in the reception space  305 . 
     In this case the seal  302  is formed separately to the housing body  300 . For example, the seal  302  may be formed by casting. 
     The housing body  300  is mounted to the proximal ring member  25  in a snap-fit arrangement ( FIG. 58( c )( i ) ). When mounted to the proximal ring member  25 , the distal end of the housing body  300  extends distally of the proximal ring member  25  and the housing body  300  is located radially inwardly of the proximal ring member  25 . 
     The housing cap  301  is mounted to the housing body  300  in a snap-fit arrangement to partially close the proximal end inlet of the reception space  305 . In this manner the housing cap  301  retains the seal  302  in position in the reception space  305 . The housing cap  301  is substantially annular in shape with a central opening to facilitate access to the seal  302  in the reception space  305 . 
     The housing body  300  may be mounted to the proximal ring member  25  before or after retraction of a wound opening. 
     In use, a wound opening  13  is made in the abdominal wall  2  and the distal O-ring  11  is inserted through the wound opening  13  into the wound interior. The seal housing and the proximal ring members  24 ,  25  are located externally of the wound opening  13  ( FIG. 58( c ) ( ii )). The seal housing may be mounted to the inner proximal ring member  25  before or after insertion of the distal O-ring  11  through the wound opening  13 . 
     To retract laterally the sides of the wound opening  13 , the outer proximal ring member  24  is pushed distally, which causes the inner proximal ring member  25  and the seal housing to move distally, while the free, proximal end of the sleeve  12  is pulled proximally ( FIG. 58( c ) ( iii )). An instrument may then be inserted through the pinhole opening  303  of the seal  302  to access the wound interior in a sealed manner. 
     The excess proximal portion of the sleeve  12  may be removed, for example by cutting away, after retraction of the wound opening  13 , as illustrated in  FIG. 58( c ) ( iii ). 
     Alternatively the excess proximal portion of the sleeve  12  may be sealed to the outer proximal ring member  24  or to the housing body  300 , for example using a clamp, to enhance the sealing effect of the instrument access device  500 . 
     As noted previously, the instrument access device  500  is particularly suitable for retracting relatively small wound openings, for example wound openings having a diameter of less than 40 mm, such as between 3 mm and 35 mm, typically between 5 mm and 12 mm. The instrument access device  500  is thus suitable to facilitate access of relatively small laparoscopic instruments, for example instruments having a diameter of less than 40 mm, such as between 3 mm and 35 mm, typically between 5 mm and 12 mm. 
     Because of the relatively small size of the instrument access device  500 , the wound opening  13  may be retracted by moving the sleeve  12  relative to the proximal ring members  24 ,  25  in a single actuation step. In particular the entire circumference of the sleeve  12  may be gripped by a single hand of a user, and opposite sides of the outer proximal ring member  24  may be gripped by the other hand of the user. The sleeve  12  may then be pulled proximally while the outer proximal ring member  24  is pushed distally to retract the wound opening  13  in a single actuation step. 
     It will be appreciated that more than one opening may be provided extending through the seal  302 . For example, two pinhole openings may be provided, spaced-apart from one another, extending through the seal  302 . In this case access may be gained to the wound interior with more than one instrument by extending an instrument through each opening in the seal  302 . 
       FIGS. 58( d ) and 58( e )  illustrate a seal/valve housing of another instrument access device according to the invention, which is similar to the seal/valve housing of  FIGS. 58( a )( i ) to 58( c ) , and similar elements in  FIGS. 58( d ) and 58( e )  are assigned the same reference numerals. 
     In this case, the housing body  300  has an insufflation lumen  313  extending therethrough, the seal  302  has an insufflation lumen  312  extending therethrough, and the housing cap  301  has an insufflation lumen  311  extending therethrough. As illustrated in  FIG. 58( e ) , the three insufflation lumena  313 ,  312 ,  311  are in alignment, and the longitudinal axis of each insufflation lumen  313 ,  312 ,  311  is parallel to the longitudinal axis of the instrument access device. An insufflation tube  310  may be inserted into the insufflation lumen  311  of the housing cap  301  to insufflate a wound interior ( FIG. 58( e ) ). 
     In  FIGS. 58( f ) and 58( g )  there is illustrated another instrument access device  320  according to the invention comprising a seal/valve housing, which is similar to the seal/valve housing of  FIGS. 58( d ) and 58( e ) , and similar elements in  FIGS. 58( f ) and 58( g )  are assigned the same reference numerals. 
     In this case the instrument access device  320  comprises a temporary insufflation seal  321  fixed to the housing cap  301  at the proximal end of the housing cap insufflation lumen  311 . The seal  321  seals the insufflation lumena  311 ,  312 ,  313  to prevent discharge of gas from the insufflated wound interior. The seal  321  may be pierced by a pointed distal end of the insufflation tube  310 , for example if it is required to further insufflate the wound interior. 
     Once the access device  320  has been fired, and the excess sleeve  12  removed, the insufflation tube  310  can be connected by piercing the temporary seal  321  which maintains pneumoperitoneum. 
     The distal ring  11  of the device  320  is configured to be sufficiently flexible for ease of insertion of the distal ring  11  through the wound opening  13  prior to retraction. The distal ring  11  is also configured to be sufficiently rigid to anchor the device  320  in position in the wound opening  13  during retraction of the wound opening  13 . The sleeve  12  has sufficient strength to facilitate transmission of the retraction force required to retract the wound opening  13 . 
     It will be appreciated that the distal ring may be provided in any suitable configuration for ease of insertion through the wound opening  13  prior to retraction. For example at least part of the distal ring  11  may be provided in the form of a shape-memory material, such as Nitinol. 
     Referring to  FIGS. 58( h ) and 58( i )  there is illustrated a further instrument access device  330  according to the invention, which is similar to the instrument access device  320  of  FIGS. 58( f ) and 58( g ) , and similar elements in  FIGS. 58( h ) and 58( i )  are assigned the same reference numerals. 
     In this case the instrument access device  330  comprises an intermediate connector  331  to connect the insufflation tube  310  in communication with the insufflation lumena  311 ,  312 ,  313 . As illustrated the intermediate connector  331  is substantially “L”-shaped. In this manner the insufflation tube  310  may be connected in communication with the insufflation lumena  311 ,  312 ,  313  with the longitudinal axis A-A of the insufflation tube  310  at the distal end of the insufflation tube  310  substantially perpendicular to the longitudinal axes B-B of the insufflation lumena  311 ,  312 ,  313 . 
     The access device  330  has an alternative insufflation connection means in the form of a tube  331  with an angle and a valve connector. The valve connector may be closed when not connected to the insufflation supply  310  ( FIG. 58( h ) ). 
       FIGS. 59 to 61  illustrate a still further instrument access device of the invention which in this case has a sheet of film material  100  extending across the inner proximal ring  25 . A valve housing  101  is mounted to an outer proximal ring  104 , for example by snap fitting and a gelatinous elastomeric seal  102  seals to an instrument  3  which in use pierces through the gel  102  and through the proximal film  104 . 
     Referring to  FIGS. 62 to 64  there is illustrated another instrument access device with valve(s)  20 . Again, as in some previous embodiments the sleeve  13  is pulled upwardly on deployment, leaving the valve  20  free of sleeve material. 
     Referring to  FIGS. 65 to 70  there is illustrated another instrument access device  200  according to the invention, which is similar to the devices of  FIGS. 13 to 16  and  FIGS. 56 to 58 , and similar elements in  FIGS. 65 to 70  are assigned the same reference numerals. 
     In this case the sleeve  12  is fixedly attached at one end to the inner proximal ring  25 , extends distally in a first layer to the distal ring  11 , is looped around the distal ring  11 , extends proximally in a second layer to the proximal rings  25 ,  24 , and passes proximally between the inner proximal ring  25  and the outer proximal ring  24 . 
     The tubular member  40  is integrally formed with the housing  27 , and the housing  27  is mounted to the inner proximal ring  25 . 
     The seal/valve  95  is provided in the form of a gelatinous elastomeric material which is mounted to the housing  27 . The seal/valve  95  has a pinhole opening  196  extending therethrough through which an instrument  3  may be extended. The opening  196  is biased towards a closed configuration. 
     A lumen  150  extends through the tubular member  40  through which an instrument  3  may be extended. The tubular member  40  has a distal opening  142  at a distal end  141  of the tubular member  40 . 
     The tubular member  40  has a skived distal end  141 , in this case. In particular the plane of the distal opening  142  is inclined relative to the longitudinal axis of the tubular member  40 , for example inclined at an angle of 45°. This configuration results in a low-profile, tapered leading end for the tubular member  40  which tapers to a point  143 . 
     The benefit of having the truncated/skived tubular member is that the point  143  on the leading edge of the truncated member  40  more easily finds the narrow, unretracted hole of the incision  1 . As it advances downwards, the taper  141  gradually spreads the incision  1  open. 
     The distal end  141  of the tubular member  40  is truncated, e.g. at an angle of 45°. This yields a narrow leading edge  143  on the tubular member  40  which more easily locates the incision  1 , through which the distal ring  11  and the sleeve  12  have already been passed. Furthermore the taper will aid the retraction of the incision  1  as it advances downwards. 
     The length of the tubular member  40  relative to the abdominal wall thickness may vary. 
     Upon pulling of the sleeve  12  proximally and pushing of the tubular member  40  distally, the incision  1  is retracted by a combined action of the skived distal end  141  of the tubular member  40  forcing the sides of the incision  1  apart and of the sleeve  12  pulling the sides of the incision  1  laterally, as illustrated in  FIG. 69 . The skived distal end  141  of the tubular member  40  assists in guiding the point  143  of the tubular member  40  to the unretracted incision  1 , for subsequent advancement of the tubular member  40  through the incision  1 . 
     After insertion of the tubular member  40  into the incision  1 , the point  143  of the tubular member  40  is located within the wound interior distally of the incision  1 . However it will be appreciated that the length of the tubular member  40  may be adjusted to suit the particular anatomy of a patient and/or to suit the preferences of a surgeon. In certain cases after insertion of the tubular member  40  into the incision  1 , the distal end of the tubular member  40  may be located within the incision  1  proximally of the wound interior. 
       FIGS. 70( a ) to 70( f )  illustrate another instrument access device  400  according to the invention, which is similar to the instrument access device  200  of  FIGS. 65 to 70 , and similar elements in  FIGS. 70( a ) to 70( f )  are assigned the same reference numerals. 
     In this case the inner proximal ring  25  has a seal  401  extending across the inner proximal ring  25 . The seal  401  prevents gas leakage from the insufflated wound interior when the wound opening has been retracted ( FIG. 70( b ) ). 
     The housing  27  is mountable to and demountable from the inner proximal ring  25  in a snap-fit arrangement ( FIGS. 70( e ) and 70( f ) ). Upon mounting of the housing  27  to the inner proximal ring  25  after the wound opening has been retracted, the pointed tip  143  of the tubular member  40  pierces the seal  401  ( FIGS. 70( d ) and 70( e ) ). 
     Mounting of the housing  27  to the inner proximal ring  25  proceeds in a manner similar to that described previously with reference to  FIGS. 26 to 28 . 
       FIGS. 70( a ) to 70( f )  illustrate a modular instrument access device  400 . The gel valve  95  has been separated from the retractor base  25 . It may be easier to introduce a cannulated gel housing  27  into an incision this way, rather than trying to do it at the same time as the retracting phase.  FIG. 70( a )  illustrates the disc of film  401  mounted in the proximal ‘O’ ring  25  to maintain pneumoperitoneum. When pneumoperitoneum has been established, the film  401  prevents pressure loss.  FIG. 70( d )  illustrates the leading tip  143  of the truncated cannula  40  beginning to pierce the disc of film  401 . In  FIG. 70( e )  the disc of film  401  has been pierced.  FIG. 70( f )  illustrates the snap-fit connection between the gel housing  27  and the proximal ‘O’ ring  25  of the retractor  400 . 
     Referring to  FIGS. 70( g ) to 70( i )  there is illustrated another instrument access device  410  according to the invention, which is similar to the instrument access device  400  of  FIGS. 70( a ) to 70( f ) , and similar elements in  FIGS. 70( g ) to 70( i )  are assigned the same reference numerals. 
     In this case, the sleeve  12  extends distally from the inner proximal ring  25  to the distal ring  11 , loops around the distal ring  11 , extends proximally from the distal ring  11  to the proximal rings  24 ,  25 , extends between the inner proximal ring  25  and the outer proximal ring  24 , and extends proximally to the housing  27  to which the sleeve  12  is fixedly attached. Before the housing  27  is mounted to the inner proximal ring  25 , any gas leakage from the wound interior through the retracted wound opening is contained within the sleeve  12 , and thus pneumoperitoneum is maintained ( FIG. 70( h ) ). No seal is provided, in this case, extending across the inner proximal ring  25 . 
       FIGS. 70( g ) to 70( i )  illustrate another modular instrument access device, the gel housing  27  with the cannula  40  is fixed to the proximal end of the sleeve  12 . A snap fit connection is used to secure the gel housing  27  to the proximal ‘O’ ring  25  of the retractor  410 . 
     In  FIGS. 71 to 73  there is illustrated another instrument access device  340  according to the invention, which is similar to the instrument access device  200  of  FIGS. 65 to 70 , and similar elements in  FIGS. 71 to 73  are assigned the same reference numerals. 
     In this case no tubular member is provided extending distally from the housing  27 . 
     The outer proximal ring  341  is releasably mounted to the inner proximal ring  25 , in this case. In particular the outer proximal ring  341  has a curved engagement surface which extends in cross-section for a quarter-revolution, as illustrated in  FIGS. 71 and 72 . The curved engagement surface rests upon the proximal side of the inner proximal ring  25 , with the sleeve  25  extending between the inner proximal ring  25  and the outer proximal ring  341 , to mount the outer proximal ring  341  to the inner proximal ring  25 . This arrangement enables the outer proximal ring  341  to be removed after retraction of the wound opening ( FIG. 73 ). 
     In use, the distal ring  11  is inserted through the wound opening into the wound interior, and the inner proximal ring  25  is located externally of the wound opening with the sleeve  12  extending from the distal ring  11  to the inner proximal ring  25  in the double-layer arrangement. The outer proximal ring  341  is then mounted to the inner proximal ring  25  with the sleeve  12  extending therebetween ( FIG. 71 ). 
     The sleeve  12  is then pulled proximally while pushing the outer proximal ring  341  distally. The outer proximal ring  341  engages the inner proximal ring  25  and thus the housing  27 , the inner proximal ring  25  and the outer proximal ring  341  all move distally to retract laterally the sides of the wound opening ( FIG. 72 ). 
     After retraction of the wound opening, the outer proximal ring  341  may be removed while the distal ring  11 , the inner proximal ring  25  and the sleeve  12  remain in position retracting the wound opening ( FIG. 73 ). 
     The outer proximal ring  341  acts as a guide to guide movement of the inner proximal ring  25  relate to the sleeve  12 . In this case, the outer proximal ring  341  does not act as a locking mechanism to lock the sleeve  12  with the wound retracted. 
       FIGS. 71 to 73  show how only half an outer proximal ring  341  is needed to provide support when firing the instrument access device  340 . The device  340  functions to retract the wound opening without the outer proximal ring  341  ( FIG. 73 ). 
     The access ports of the invention can be used in a number of ways. In one method the retractor is used as described above, the distal inner ring  11  being inserted into an incision  1 , the outer ring being slid to controllably radially expand the incision  1 . The retractor may then be locked in position. If necessary, the outer ring can be moved further downwardly to create a larger incision. 
     In some arrangements an instrument may be bent manually outside the body and the bent instrument is delivered through the access port to readily access the operative site. 
     In a further embodiment an instrument is inserted into the access port and the surgeon uses the abdominal wall itself to bend the instrument and then insert the bent section further into the abdomen. 
     It will be appreciated that the instrument access device of the invention may have a valve or seal in the form of a gelatinous elastomeric material, or in any other suitable form, for example a lip seal. 
     The access ports of the invention have at least some of the following advantages: 
     Controlled Radial Expansion
     1. Greater access using smaller incision   2. Can vary incision size as need be (e.g. specimen removal during lap coli.)   

     Greater Sealing Capabilities
     1. No gas leakage from the wound margins   2. Cannot be inadvertently pulled out of the incision   3. Will seal any incision and never require secondary sealing method (suture, Hassan port, etc.)   

     Eliminate Intra-Abdominal Profile
     1. Gives back more working space in the abdomen (critical in pelvic surgery)   2. Perineal access for operations such as Radical Prostatectomy.   

     Protection of Wound from Infection and Cancer Seeding
     1. Tight seal with no “chimney stack” effect   2. Upon removal all areas of potential contamination are isolated from the incision   

     Reduced Extra-Abdominal Profile
     1. Will increase the effective working length of an instrument   2. Greater working area outside the abdomen   

     Increase the Freedom of Movement of Conventional Laparoscopic Instruments 
     The instrument access device of the invention enables a surgeon to gain access to a wound interior using an instrument while minimising the incision size at the wound interior to minimise the possibility of post-operative herniation. 
     The retractor of the invention may be inserted through the abdominal wall as described below. An initial thin incision may be made in the abdominal wall and an inner distal ring of the retractor may be attached to an insertion tool. The ring is flexible and can be stretched or bent for ease of insertion through the incision. 
     In some cases the ring may be inserted through the incision using a blunted or round-nosed obturator tool. 
     Alternatively the ring may be inserted using an obturator/trocar tool with a leading cutting blade. In this case the tool itself makes an incision in the abdominal wall, allowing the distal ring of the retractor to be delivered and deployed. 
     Further means and methods suitable for introducing the instrument access device of the invention into a wound opening, and suitable for withdrawing the instrument access device of the invention from a wound opening are described in International patent application published under Nos. WO 2004/026153, WO 2004/030547, WO 2004/054456, and WO 2005/009257, the relevant contents of which are incorporated herein by reference. 
     The invention is not limited to the embodiments hereinbefore described, with reference to the accompanying drawings, which may be varied in construction and detail.