EP3509502A1

EP3509502A1 - Surgical retractor

Info

Publication number: EP3509502A1
Application number: EP17767888.5A
Authority: EP
Inventors: McNulty ALAN
Original assignee: Sheffmed Trade Services Ltd
Current assignee: Sheffmed Trade Services Ltd
Priority date: 2016-09-06
Filing date: 2017-09-06
Publication date: 2019-07-17
Also published as: GB201615116D0; GB2553372A; WO2018046916A1

Abstract

Embodiments of the present invention provide a surgical retractor system (10) for holding tissue out of the way of a surgeon during a surgical procedure. The retractor system is operable to apply forces to tissue in a continuous range of directions and comprises a handle (12), a retaining member (14) that is connectable to the handle such that the retaining member is operable to articulate relative to the handle, and a retractor stem (16). The retaining member comprises a spherical seat (22) and the retractor stem comprises a plurality of spherical stoppers (26) that are arranged to engage the spherical seats.

Description

Surgical Retractor

TECHNICAL FIELD

The present invention relates to a surgical retractor for maintaining access to a surgical site by holding surrounding tissue away from an area on which a surgeon wishes to operate.

BACKGROUND

During surgical procedures the tissue surrounding a surgical site is often retracted by an assistant who holds the tissue using a surgical hook. Retractor apparatuses configured to retain one or more hooks have also been developed. However, a drawback of such apparatuses is that they are often only operable to apply tension in a limited range of directions, so there may be procedures that they are not suitable for.

Another drawback of existing apparatuses is that there is typically limited scope to reconfigure the geometry of the apparatus to suit a particular procedure being performed on a given individual. Accordingly, there may be procedures that prior art surgical retractors are unsuitable or ill adapted for.

It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.

SUMMARY OF THE INVENTION

According to an aspect of the invention for which protection is sought there is provided a surgical retractor system comprising:

a handle;

a retaining member being connectable to the handle such that the retaining member is able to articulate relative to the handle; and

a retractor stem, said retractor stem comprising an elongate member having a tissue engaging portion at an end thereof and a plurality of spherical stoppers spaced apart along a length of the elongate member,

wherein:

said retaining member comprises a plurality of recesses, each recess defining a spherical seat and being arranged to allow a portion of the retractor stem to pass through the retaining member; and the spherical seats are operable to engage the spherical stoppers, thereby limiting movement of the retractor stem through the retaining member. Such a surgical retractor system may be held in place in the vicinity of a surgical site using an articulated arm. The surgical retractor system can then be used to hold tissue out of the way of a surgeon who requires access to the surgical site by engaging the tissue with the tissue engaging portion of the retractor stem and then fixing the retractor stem to the retaining member by inserting the retractor stem into one of the recesses and allowing a spherical stopper of the retractor stem to engage the spherical seat.

The retaining member may be connectable to the handle via a bolt. The retaining member may be operable to rotate relative to the handle when the bolt is partially loosened and may be substantially fixed relative to the handle when the bolt is tightened.

Providing a spherical stopper on the retractor stem and a spherical seat on the retaining member allows the retractor stem to apply a force to tissue in a continuous range of directions, as the retractor stem is operable to rotate relative to the retaining member about three mutually perpendicular axes.

In an embodiment the surgical retractor system further comprises a clamp, said clamp being attachable to the retaining member, wherein:

the clamp comprises a clamp recess defining a clamp spherical seat;

the clamp recess is arranged such that a portion of the retractor stem is able to pass through the clamp at the clamp recess; and

the clamp spherical seat is operable to engage said spherical stoppers, thereby limiting movement of the retractor stem through the clamp. Providing such a clamp may improve the flexibility of the system as it allows the retractor stem to be attached to the retaining member indirectly and from a location that is somewhat distant from the retaining member.

Optionally, at each of said recesses said retractor stem is operable to pass through said retaining member in a direction perpendicular to a first surface, said first surface being a surface of the retaining member;

at said clamp recess said retractor stem is operable to pass through said clamp in a direction perpendicular to a second surface, said second surface being a surface of the clamp; and when said clamp is attached to said retaining member said first surface is inclined relative to said second surface. Allowing the retractor to pass through the clamp recess in a direction that is inclined relative to the direction in which it can pass through the recess on the retaining member increases the range of directions in which the retractor system can be used to apply forces to tissue.

Further optionally, said first surface may be substantially perpendicular to said second surface when said clamp is attached to said retaining member. In an embodiment said plurality of recesses may comprise a first recess and a second recess, wherein:

at said first recess said retractor stem is configured to pass through the retaining member in a direction perpendicular to a first surface of the retaining member;

at said second recess said retractor stem is configured to pass through said retaining member in a direction perpendicular to a second surface of the retaining member; and

said first surface is inclined relative to said second surface. Optionally, said retaining member is arcuate. This may allow the retaining member to be positioned such that a plurality of recesses are positioned near to the surgical site, and each of the recesses may be operable to secure a retractor stem in position from a different direction. The surgical retractor system may comprise a plurality of said retaining members. Two of said retaining members may be simultaneously connectable to the handle. Further optionally, each of the retaining members may comprise a connecting portion, wherein each of said retaining members may be connected to said handle or another of said retaining members at said connecting portions. Each of said retaining members may comprises a plurality of connecting portions. Providing a plurality of retaining members with connecting portions may allow the system to be customised to the requirements of particular surgical procedures.

In an embodiment said plurality of retaining members comprises at least a first retaining member having a first number of recesses and a second retaining member having a second number of recesses, said second number being greater than said first number. Providing different retaining members with different numbers of recesses may allow the system to be customised for the requirements of a particular surgical procedure.

Optionally, said tissue engaging portion comprises a surgical hook. Alternatively, said tissue engaging portion could comprise a retractor. The retractor may be provided with a flat blade for engaging tissue.

The surgical retractor system may further comprise an articulated arm having a holding portion operable to hold said handle. Such an articulated arm may be used to position the surgical retractor system in the vicinity of a surgical site.

According to another aspect of the invention for which protection is sought there is provided a surgical retractor frame comprising at least one malleable rod and at least one connector, wherein:

the malleable rod comprises a plastically deformable stiffening portion and a plastics material surrounding the stiffening portion; and

the connector comprises two connector clamps rotatably mounted on a connector bar, each connector clamp being arranged to receive and secure a portion of the malleable rod. Advantageously, such a frame may be operable to provide fixing locations for elastic stays for use in surgery arranged in substantially any desired shape around a surgical site.

In an embodiment the plastics material comprises a natural or synthetic rubber, for example silicone rubber.

In an embodiment, the stiffening portion comprises a metal wire. Such a wire may provide an appropriate balance of stiffness, ductility and malleability. The stiffening portion may comprise a coil of metal wire, optionally a plurality of coils of metal wire. In an embodiment the metal wire comprises SAE 304 stainless steel. This material provides suitable ductility and malleability for making a malleable rod for use in a surgical retractor frame.

It will be understood that the precise configuration of the stiffening portion will be determined by the skilled person according to the required mechanical characteristics of the rod. In an embodiment the plastics material is moulded over the stiffening portion. Advantageously, this provides good attachment between the plastics material and the metal core. In another embodiment at least the end portions of the malleable rod are cylindrical and wherein the each of the connector clamps has an annular portion arranged to receive at least an end portion of the malleable rod, the annular portion being switchable from an open state in which the annular portion has a minimum internal diameter greater than the diameter of the end portions of the malleable rod and a closed state in which the annular portion has a minimum internal diameter less or equal to than the diameter of the end portions of the malleable rod. Optionally, the connector clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to the external diameter of the end portions of the malleable rod to a value less than the external diameter of the end portions of the malleable rod. Accordingly, rotation of the cam may cause the connector clamp to switch from the open position to the closed position. A lever may be connected to the cam to facilitate rotation of the cam.

According to another aspect of the invention for which protection is sought there is provided a surgical retractor system comprising a surgical retractor frame as described above and one or more stay clamps, each of the stay clamps being arranged to be secured to a portion of the malleable rod and defining at least one recess arranged to receive a portion of an elastic stay. Advantageously, the stay clamps may be positioned on the malleable rod to provide locations for fixing elastic stays around a surgical site.

In an embodiment the stay clamp comprises at least two of said recesses.

Optionally, the stay clamp may have an annular portion arranged to receive at least a portion of the malleable rod, the annular portion being switchable from an open state in which the annular portion has an internal diameter greater than the diameter of the portion of the malleable rod and a closed state in which the annular portion has an internal diameter less than or equal to the diameter of portion of the malleable rod. Further optionally, the stay clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to the external diameter of the portion of the malleable rod to a value less than the external diameter of the portion of the malleable rod.

In an embodiment the stay clamp comprises a lever, the lever being operable to switch the stay clamp between the open state and the closed state. Advantageously, this allows easy switching of the clamp between the closed and open states during a surgical procedure. This may allow the stay clamps to be easily repositioned.

In an embodiment the surgical retractor system further comprises at least one elastic stay. Optionally, the elastic stay comprises an elongate stem having a tissue engaging portion at an end thereof and a plurality of spherical stoppers spaced apart along a length of the elongate member. Further optionally, wherein the tissue engaging portion is provided on an end piece of the elastic stay, the end piece being detachable from the elongate stem. Advantageously, this allows different end pieces with different tissue engaging portions to be provided, and a surgeon may select one or more end pieces with an appropriate tissue engaging portion for a particular type of tissue or surgery. Optionally, the system comprises a plurality of interchangeable end pieces.

According to a further aspect of the invention for which protection is sought there is provided a clamp for a surgical retractor system comprising an annular portion being switchable from an open state in which the annular portion has a first internal diameter to a closed state in which the annular portion has a second internal diameter less than the first internal diameter,

the clamp further comprising a recess arranged to receive a portion of an elastic stay. Advantageously, such a clamp may be connected to a frame comprising a malleable rod to provide an appropriate location for holding an elastic stay during a surgical procedure.

In an embodiment, the clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to a first value to a value less than the first value. According to a further aspect of the invention for which protection is sought there is provided a connecting portion for a surgical retractor system comprising two connector clamps rotatably mounted on a connector bar, each connector clamp being arranged to receive and secure a portion of a cylindrical malleable rod. Optionally, the connector clamps may be clamps as described above. Advantageously, the rotatable mounting of the connector clamps on the connector bar allows the connector to receive end portions of malleable rods from substantially any angle. BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described by way of example only, with reference to the accompanying figures, in which:

Figure 1 shows a surgical retractor system in an embodiment of the present invention;

Figure 2 shows another view of the surgical retractor system shown in figure

1 ;

Figure 3 shows a handle of a surgical retractor system in an embodiment of the present invention;

Figure 4 shows a retaining member of a surgical retractor system in an embodiment of the present invention;

Figure 5 shows a clamp for attaching to a retaining member in an embodiment of the present invention;

Figure 6 shows a cross section through a retaining member and an attached clamp in an embodiment of the present invention;

Figures 7a and 7b show cross sections at different locations along the length of a retaining member in another embodiment of the present invention

Figure 8 shows a surgical retractor system in an embodiment of the present invention;

Figures 9A and 9B show cross sectional views of a malleable rod for use in a surgical retractor frame in an embodiment of the present invention;

Figures 10A and 10B show a clamp part of a connector for use in a surgical retractor frame in an embodiment of the present invention;

Figure 11 shows a connector bar for use in a surgical retractor frame in an embodiment of the present invention;

Figure 12 shows a stay clamp in an embodiment of the present invention; Figure 13 shows a lever with an integrated cam for attaching a stay clamp or a connector clamp to a malleable rod; and

Figures 14A and 14B show a pin for fixing the lever shown in figure 13 to a stay clamp or a connector clamp.

DETAILED DESCRIPTION

Figure 1 shows a surgical retractor system 10 comprising a handle 12 having a holding portion 34 and being connected to two retaining members 14 at connecting portions 18. Each of the retaining members 14 comprises an arcuate member having a plurality of recesses 20, each recess having an opening 24 and a spherical seat 22. The retractor system 10 also comprises a plurality of retractor stems 16 (of which only one is shown). Each retractor stem comprises an elongate member having a plurality of spherical stoppers 26 disposed along its length, such that a plurality of narrow, cylindrical regions 28 are disposed between adjacent spherical stoppers 26. The retractor stems also comprise a tissue engaging portion 30 at an end thereof. In the illustrated embodiment the tissue engaging portion is a surgical hook, but it will be understood that any type of surgical hook or surgical retractor would be suitable. For example, the tissue engaging portion may comprise Langenbeck retractor, a two pronged retractor or a three pronged retractor.

The surgical retractor system 10 shown in figure 1 can be used to hold tissue surrounding a surgical site out of the way of a surgeon who requires access to the site. The handle 12 and the retaining members 14 connected to the handle are arranged to be held in position near to the surgical site by an articulated arm (not shown) that is arranged to grip the handle 12 at holding portion 34. A suitable articulated arm is produced by GEOMED Medizintechnik GmbH under the trade name ASSISTO®. Tissue surrounding the surgical site may then be retracted by engaging the tissue with the hook 30 of a retractor stem 16 and then fixing the hook and tissue in a desired position by placing the retractor stem into one of the recesses 20 by passing a cylindrical portion of the retractor stem 16 through an opening 24 of one of the recesses 20 and moving the retractor stem through the recess in an axial direction (i.e. along axis C as shown in figure 6) until the spherical stopper 26 above the cylindrical portion engages the spherical seat 22 of the recess 20. It will be understood that it is advantageous for the retractor stem 16 to be in tension when it is fixed relative to the retaining member 14, as this causes the spherical stopper to firmly engage the spherical seat and retains the hook in engagement with the tissue. This substantially prevents further relative movement between the tissue, the retractor stem 16 and the retaining member 14. Tension in the retractor stem is typically maintained by the reaction force of the retracted tissue against the hook 30.

A particular advantage of providing spherical stoppers 26 that are arranged to engage spherical seats 22 is that this allows significant flexibility in the angle at which a force can be applied to tissue by a retractor stem that is held in tension between the tissue and the retaining member 14. This is because the spherical stoppers and spherical seats are able to fix the position of a point on the retractor stem relative to the retaining member whilst allowing significant flexibility in the angular orientation of the retractor stem relative to the retaining member.

Another advantage of the surgical retractor system 10 of embodiments of the present invention is that it allows the location at which the retractor stems 16 are fixed to be varied without repositioning the entire system 10. This is achieved by allowing the retaining members 14 to articulate relative to the handle 14. Figures 3 and 4 show, respectively, a handle 12^' and a corresponding retaining member 14\ which can be used in embodiments of the present invention. Retaining member 14^' can be connected to handle 12^' in a manner that permits articulation of the retaining member 14^' relative to the handle 12^' by inserting raised portion 40 of the retaining member 14^' into one of the apertures 44 from the underside of the handle 12^' (i.e. in the direction indicated by arrow A). Raised portion 40 is sized so as to produce a clearance fit within the apertures 44. The connection is then completed by inserting a bolt (not shown) having a head that is larger in diameter than the apertures 44 into threaded hole 42. When the bolt is tightened the head of the bolt engages surface 46, and friction between the head of the bolt and surface 46 substantially prevents articulation of the retaining member 14^' relative to the handle 12\ If the bolt is loosened then the friction between the head and surface 46 is reduced, and rotation of the retaining member 14^' relative to the handle 12^' about a central axis of the aperture 44 can be performed. Preferably, the head of the bolt is sufficiently large that it hand tightening can be sufficient to secure the retaining member 14^' relative to the handle 12\ and the bolt can be loosened by hand to allow articulation of the retaining member 14^' relative to the handle 12\

Allowing the retaining member 14^' to rotate relative to the handle 12^' provides additional flexibility in the direction from which the surgical retractor system can apply a force to tissue. A surgeon wishing to use the retractor system of the present invention to move a portion of tissue in a particular direction may loosen the bolt holding a retaining member 14^' to the handle 12^' so that the retaining member can be rotated relative to the handle. The surgeon may then rotate the retaining member until one of the spherical seats 22 lies along or close to a line that starts from the portion of tissue that the surgeon wishes to apply a force to and that is defined in the direction of the required force. The surgeon can then engage the tissue with the tissue engaging portion (e.g. a hook 30) of a retractor stem 16, and then fix the retractor stem in place by inserting one of the spherical stoppers 26 into the aligned spherical seat 22, ensuring that the retractor stem remains in tension when the spherical stopper is inserted into the spherical seat. If the surgeon wishes to vary the magnitude of the force applied to the tissue then they may change the spherical stopper that is inserted into the aligned spherical seat 22. As will be readily understood by the skilled person changing to a spherical stopper that is located closer to the tissue engaging portion without moving the retaining portion 14^' will cause the force applied to the tissue to be increased, whereas changing to a spherical stopper that is located further away from the tissue engaging portion without moving the retaining portion 14^' will cause the force applied to the tissue to be decreased.

If required, an additional, similar, retaining member may be connected to the retaining member 14^' by inserting an upstanding connecting portion 40 into bore 48, and then securing the retaining members together using a bolt similar to the one used to secure the retaining member 14^' to the handle 12\ This may allow a surgeon to extend the area in which the retractor system is able to perform tissue retraction. Furthermore, the additional retaining member may be articulated relative to the retaining member that is connected to the handle 12\ This may allow the retractor system to perform tissue retraction for large surgical sites in which covered by a single retaining member could not provide enough spherical seats to provide adequate retraction. The retaining member 14 shown in figure 4 is provided with eight recesses 20. However, it will be understood that this is merely exemplary, and in some embodiments a different number of recesses may be provided. Indeed, in some embodiments a retractor system may be provided with a plurality of retaining members having different numbers of recesses, thereby allowing a surgeon to select the most appropriate size of retaining member for a particular surgical procedure. This may also allow a surgeon to connect retaining members of different sizes together to produce a retaining member having the required number of recesses, or to produce a retaining member that is articulable at a location where articulation is likely to be advantageous. In some embodiments, different retaining members may have different radii of curvature to each other. This may improve the flexibility of the system.

It will be understood that a retractor stem 16 that has been inserted into one of the recesses 20 so that one of the spherical stoppers of the retractor stem engages one of the spherical seats 22 will be rotatable about three mutually perpendicular axes. The retractor stem will be operable to rotate freely about its longitudinal axis, which allows the direction of the hook 30 to be changed after the spherical stopper is inserted into the spherical seat. The retractor stem 16 will also be operable to rotate about two additional axes that are perpendicular to each other and the longitudinal axis of the retractor stem, although the rotation about the additional axes will be limited to rotation within a particular arc, as the cylindrical regions 28 that are adjacent to the spherical stopper 26 that has been inserted into the retractor stem will engage the retaining member at a certain point in the rotation of the retractor stem 16 about each of the additional axes, thereby preventing further rotation.

Figure 5 shows a clamp 50 that may be connected to a retaining member 14, 14^' of a system according to the present invention so as to provide a recess and spherical seat that is perpendicular to the recesses and spherical seats on the retaining member. The clamp 50 comprises a recess 52 that defines a cylindrical seat 54. The recess and cylindrical seat are substantially the same size as the recesses 20 and cylindrical seats 22 that are provided on the retaining members 14, 14^' shown in figures 1 , 2 and 4. Accordingly, a similar retractor stem 16 may be retained in the clamp 50 by inserting a cylindrical portion 28 of the retractor stem into the recess 52 and then moving the retractor stem through the clamp 50 in an axial direction (i.e. along axis B as shown in figure 6) until the spherical stopper adjacent to the inserted cylindrical portion engages the cylindrical seat 54.

The clamp 50 may be connected to the retaining member 14 by either sliding the retaining member into the partially enclosed region 62 defined between the side walls 58A, 58B, the flanges 56A, 56B and the connecting wall 64, or by inserting the retaining member through the gap between the flanges 56A, 56B. If the retaining member is to be inserted through the gap between the flanges then the side walls 58A, 58B and the connecting wall 64 may be deformed so as to move the flanges 56A, 56B out of the way of the retaining member 14. Once the retaining member 14 is fully inserted into the partially enclosed region 62 the side walls and the connecting wall return to their undeformed positions.

Once the retaining member has been inserted into the partially enclosed region 62 it is held in place within the partially enclosed region by friction between the clamp and the retaining member.

Clamp 50 is also provided with a threaded bore 60, which may be used to screw an extension arm (not shown) onto the clamp.

A cross sectional view showing the clamp 50 attached to the retaining member 14 is shown in figure 6. The inner surfaces of the partially enclosed region 62 engage the outer surfaces of the retaining member 14, so as to produce a friction fit. As shown in figure 6, the recess 52 and the spherical seat 54 of the clamp 50 are substantially perpendicular to the recess 20 and spherical seat 22 of the retaining member 14. This can allow a surgeon to apply forces to tissue in directions that would not be possible using a retractor stem inserted into the recess 20 on the retaining member 14, as the arc through which a retractor stem inserted into the recess 52 (i.e. the recess on the clamp 50) may be rotated in the plane shown in figure 6 is inclined by 90 degrees to the arc through which a retractor stem inserted into the recess 20 could be rotated in the plane shown in figure 6. In some embodiments, a retractor stem inserted into the recess 52 may be rotatable within an arc of at least 90 degrees in the plane shown in figure 6, and a retractor stem inserted into the recess 20 may also be rotatable through an angle of at least 90 degrees in the plane shown in figure 6. This allows the possibility of applying forces in a substantially continuous range of directions, as the directions in which forces can be applied using the a retractor stem inserted into recess 20 at least partially overlap the directions in which forces can be applied by a retractor stem inserted into recess 52. It will be understood that whilst the clamp 50 is shown in a position that covers one of the recesses 20 in the retaining member 14 in figure 6, it would also be possible to position the clamp in a region between recesses 20 on the retaining member, so that none of the recesses in the retaining member 14 are blocked by the clamp 50. Furthermore, although only one clamp is shown, it will be understood that a plurality of clamps 50 may be attached to a single retaining member 14 depending on the requirements of a particular surgical procedure. The recesses 20 on the retaining member and the recess 52 on the clamp are provided with frusto-conical surfaces 57, 52 opposing the spherical seats 22, 54. The frusto-conical surfaces 57, 52 allow a retractor stem having a spherical surface engaging one of the spherical seats 22, 54 to articulate relative to the retaining member or the clamp, such that the articulation is only limited when the cylindrical portion of the retractor stem adjacent to the spherical surface comes into contact with the frusto-conical surface. In some embodiments the apex angle defined by the frusto-conical surface may be approximately 120 degrees. This may allow a retractor stem having a spherical surface engaging one of the spherical seats 22, 54 and having its longitudinal axis aligned with the central axis B, C of the spherical seat to rotate through up to 60 degrees about two axes that are perpendicular to each other and the central axis of the spherical seat.

In other embodiments the apex angle defined by the frusto-conical surface may, for example, be between 100 and 140 degrees. It will be understood that the apex angle defined by a frusto-conical surface is the angle that would be defined at the apex of a conical surface extended from the frusto-conical surface.

Figures 7a and 7b show cross sections through a retaining member 14^" in another embodiment of the present invention. At the location shown in figure 7a the retaining member has an integrally formed upstanding portion 70 in which a recess 52^' defining a spherical seat 54^' is defined. Recess 52^' allows a retractor stem to pass through the retaining member 14^" along a generally horizontal axis. At the location shown in figure 7b the retaining member does not have an upstanding portion. A recess 20^' defining a spherical seat 22^' is provided in the retaining member 14^" at the location shown in figure 7b. The recess 20^' allows a retractor stem to pass through the retaining member along a generally vertical axis. A retaining member 14^" may alternate between regions having recesses 20^' and regions having upstanding portions 70 and recesses 52\ This may allow the possibility of applying forces in a substantially continuous range of directions, as the directions in which forces can be applied using the a retractor stem inserted into recesses 20^' at least partially overlap the directions in which forces can be applied by a retractor stem inserted into recesses 52\ The term "spherical" when used herein to describe stoppers and seats is not intended to require that the stoppers and seats have surfaces that are precisely spherical. Instead, the term "spherical" is merely intended to mean that the surfaces sufficiently close to spherical that the seat and the stopper can be maintained in contact with one another without preventing relative rotation of the seat and the stopper about three mutually perpendicular axes. It will also be understood that the seat and the stopper will typically have surfaces define part spheres, not entire spheres.

Figure 8 shows a surgical retractor system 1 100 comprising a frame 1 102 having a plurality of stay clamps 1104 attached thereto. The frame comprises two malleable rods 1108A, 1108B connected to each other at their respective ends by connectors 1 1 10. Each of the stay clamps has two recesses formed therein which are each arranged to receive a portion of an elastic stay 1 106 thereby to limit movement of the elastic stay.

Figure 9A shows a schematic representation of a cross section taken along a longitudinal plane through one of the malleable rods 1108A, 1 108B shown in figure 8 and figure 9B shows a cross section taken on a plane perpendicular to the longitudinal axis of one of the malleable rods 1108A, 1108B. The malleable rod 1 108 comprises a coil of metal wire 1 1 16 to provide stiffness and a silicone rubber cylinder moulded around the coil. The metal coil 11 16 can be made from any appropriate plastically deformable alloy. In the illustrated embodiment the coil is made from SAE 304 stainless steel. The wire that the coil is made from may have a diameter of approximately 1-3mm and the overall diameter D of the turns of the coil may be between approximately 5-10mm. The pitch P between adjacent turns of the coil can be between 3-15mm. In an embodiment, the diameter of the wire may be 2mm, the overall diameter D of the turns of the coil may be 7mm and the pitch P between adjacent turns may be 5mm. It will be understood that the precise configuration of the coil can be determined by the skilled person according to the required mechanical characteristics of the malleable rods 1108A, B.

It will be understood that any other metal that displays appropriate malleability and ductility may be used in place of SAE 304 stainless steel, and that any type of silicone rubber, or another plastics material, may be used to make the cylinder, providing such materials are compatible with the required sterilising methods and display appropriate mechanical properties. In use, the malleable rods 1108A, B are able to be plastically deformed into a desired shape for use in a particular type of surgery and for the needs of a particular patient geometry. Accordingly, it will be understood that although the cross section shown in figure 9A is through a malleable rod when it is substantially straight, the same malleable rod 1 108 may be relatively easily deformed to a curved shape similar to those shown in figure 9C and figure 8. Furthermore, although the rods 1108A, 1108B will be referred to herein as "malleable", it will be understood that they may be both malleable and ductile so that they can be appropriately plastically deformed.

The coil is surrounded by a cylindrical silicone rubber outer portion 11 14, which is moulded over the coil 11 16. The use of silicone rubber to make the outer portion 1 114 allows the malleable rod 1 108 to be sterilised by conventional methods including autoclaving or exposure to gases such as Ethylene Oxide. Furthermore, the outer portion is sufficiently flexible to allow the malleable rod to be plastically deformed in use and provides a convenient surface to which the stay clamps 1 104 and the clamps 1 1 12 of the connectors 11 10 may be attached, as will be described in more detail below.

Figure 10A shows a connector clamp 1 112 which is arranged to be releasably connected to a connector bar 1 1 10 as shown in detail in figure 1 1A-B. Connection between the connector bar and the connector clamp is effected by passing resilient fingers 1 120A, 1120B through one of the through apertures 1122 in the connector bar. Insertion of the resilient fingers through the aperture 1 122 causes them to be deformed inwardly as cam surfaces 1126A, 1 126B engage the edges of the aperture 1 122. Once the resilient fingers 1 120A, 1120B have both been fully inserted into the hole 1122 the protruding portions 1 132A, 1132B pass the inner surface of the aperture 1 122 and accordingly the resilient fingers snap back to their neutral position as shown in figure 10A. The connector bar 11 10 is then fixed between surfaces 1 128 and 1130. Disconnection of the clamp connector 1 112 from the connector bar 1 110 may be effected by a user squeezing the protruding portions 1132A, 1132B together such that surfaces 1 130A, B may pass through the aperture 1 122. A particular advantage of connecting the connector clamps to the connector bar in this way is that it once the connection is made rotation of the connector clamps relative to the connector bar is still possible. This allows the connector clamps to receive the ends of the malleable rods 1108A, B from any angle. In use two of the connector clamps are connected to a connector bar as described above, so as to provide a connector having two clamps rotatably mounted to the connector bar 1 110. The malleable rods 1108A, 1 108B each have an external diameter that is slightly less than, or substantially equal to, the inter diameter of the aperture 1 140 in the connector clamps. Accordingly, the malleable rods may be inserted into the apertures 1 140 in an axial direction. Once a malleable rod is inserted into one of the apertures 1 140 the malleable rod may be releasably connected to the connector clamp by moving lever 1 142 in a downward direction to a "closed" position. Movement of the lever 1142 may be limited by engagement with stop 1146. This forces the cam 1 144 connected to the lever 1142 against the outer surface of the malleable rod. Because of the resilience of the silicone outer portion this causes the outer portion to be compressed in the region around the cam 1 144 and therefore prevents further movement of the malleable rod through the aperture 1 140. Once the lever passes a threshold position the pressure angle between the cam 1144 and the outer portion of the malleable rod is such that the force exerted on the cam by the malleable rod acts to hold the cam and associated lever in the closed position rather than the open position. The connection between the connector clamp and the malleable rod may subsequently be released simply by moving the lever 1 142 back to the "open" position shown in figure 10A.

Figures 10B and 10C show front and side views of the main body 1 150 of the connector clamp 1 1 12, which does not have the lever 1142 and associated cam 1 144 attached. It will be understood that the lever 1 142 and cam 1144 may be formed as a single lever part as shown in figure 13, and that this part may have an aperture 1 145 therethrough to receive a shaft 1 148 as shown in figure 14. The lever part may be connected to the main body by aligning the aperture through the lever part with the apertures 1152 in the main body. A shaft 1 148 may then be passed through the aligned apertures and fixed to either the main body or the lever part. In the illustrated embodiment an interference fit is produced between protrusions 1 149 and one of the apertures 1 152 in the main body, and the lever part is able to rotate freely on the shaft 1 148. In alternative embodiments, the aperture through the lever part may have a slightly smaller diameter than the apertures 1 152 in the main body and the shaft may have a diameter that allows it to rotate freely in the apertures 1152 but creates an interference fit between the lever part and the shaft. Alternatively, the aperture in the lever part may have a larger diameter than the apertures 1152 in the main body, and the shaft 1142 may have a diameter that allows the lever part to rotate freely on the shaft but causes an interference fit between the shaft and the inner surfaces of the apertures 1152. As best seen in figures 10A and 10C, connector clamps 11 12 are provided with lobes 1 156 each having a recess 1 158 therein. As will be described in more detail below, the recesses 1158 are sized so as to be able to receive a portion of an elastic stay 1 106 and to limit movement of the elastic stay through the recess.

Figure 12A shows a stay clamp 1104 which may be attached to one of the malleable rods 1 108A, B. Similar to the connector clamps 1112, the stay clamp is provided with an aperture 1160 that has an internal diameter that is substantially equal to or slightly larger than the diameter of the malleable rods 1108A, 1108B. Accordingly, one of the malleable rods may be inserted through the aperture 1 160 in an axial direction so that the stay clamp 1 104 is at a desired position on the malleable rod 1 108. The position of the stay clamp relative to the malleable rod may then be fixed by moving the lever 1142 in a downward direction. It will be understood that the operation and assembly of the lever in the stay clamps is substantially the same as the corresponding operations for the connector clamps. The stay clamp is provided with lobes 1164 each having a recess 1 166 therein. Recesses 1 166 in the stay clamps are similarly sized to the recesses 1158 in the connector clamps. Accordingly recesses 1166 are able to receive a portion of an elastic stay 1 106 and to limit movement of the elastic stay through the recess.

A particular advantage of the stay clamps is that these can be positioned at any required axial location on the malleable rods, and they can easily be repositioned. This provides an operator with flexibility in their choice of where to locate the recesses 1 166 that act as fixing locations for the elastic stays 1 106. Furthermore, the angular position of the stay clamps 1 104 about a central axis of a malleable rod 1 108 to which a stay clamp is attached can also be adjusted by simply moving the lever 1162 from the closed position to the open position, rotating the stay clamp to a desired angular position and then returning the lever to the closed position. Alternatively, an operator may keep the lever 1162 in the closed position and may rotate the stay clamp 1104 on the malleable rod to which it is attached by simply applying a sufficiently large torque to the stay clamp to overcome the friction between the stay clamp and the malleable rod. As will be described in more detail below, this provides a convenient way for a surgeon to make find adjustments in the tension applied by a surgical stay during a surgical procedure.

A surgical retractor system according to the present invention may comprise a plurality of elastic stays 1106 as shown in figure 8. Each of the elastic stays comprises an interchangeable end piece 1174A, 1174B, 1 174C connected to an elastic retractor stem. The end pieces each comprise a tissue engaging portion which may be a sheet metal retractor having three hooked portions 1 176A, two wire hooks 176B or a single wire hook 1 176C. Alternatively, the tissue engaging portion may comprise a Langenbeck retractor, a two pronged retractor or a three pronged retractor. The tissue engaging portion is connected to a wire coil which is embedded in the moulded plastics connecting part 1 178.

The elastic stems 1 168 each comprise a moulded silicone stem having a plurality of spherical stoppers 1170 separated by cylindrical regions 1172. In use an elastic stem may be fixed relative to a stay clamp or a connector clamp by inserting one of the cylindrical regions 1172 into a recess 1158, 1166 of the clamp and then moving the stem through the recess in an axial direction until a spherical stopper 1 170 engages the clamp and prevents further movement of the stem through the recess.

The use of a surgical retractor system in an embodiment of the invention for assisting in a surgical procedure will now be described with reference to the accompanying drawings. It will be understood that all of the components of the system 1 100 may be sterilised by conventional methods such as autoclaving or exposure to Ethylene Oxide, and that such sterilisation must be performed prior to using the components in a surgical procedure. However, in some embodiments the components may be supplied sterile in sealed packaging, thereby obviating the need for an end user to sterilise the components before their first use.

Once a site has been prepared for surgery a surgeon may assemble the retractor frame 1 102 such that the site is surrounded by the frame 1 102. A frame of the desired size and shape may be produced by selecting a combination of malleable rods 1 108 having a length sufficient to produce a closed frame of the desired size. The frame 1 102 shown in figure 8 comprises a first malleable rod 1 108A and a second malleable rod 1 108B having a length shorter than that of the first malleable rod 1 108A. The malleable rods are manually bent into the required shape and then connected by connectors 11 10 to form a continuous loop. In the embodiment shown in figure 8 each of the malleable rods has been bent to form an arc approximately defining a portion of the circumference of a circle. However, it will be understood that depending upon the size and shape of the surgical site a surgeon may bend the rods into a different shape. Furthermore, although only two different sizes of malleable rod 1 108A, 1108B are shown in figure 8, it will be understood that several different sizes may be available so as to enable the creation of frames of a wide range of different sizes. Furthermore, the circumference of a closed frame made from a given combination of one or more malleable rods 1 108 and one or more connectors 1110 may be reduced by increasing the length of malleable rod 1 108 that is passed through the aperture 1 140 of the connector clamps 11 12 before the connector clamp 1 1 12 is fixed to the malleable rod. One or more stay clamps may be positioned on each of the malleable rods that are to be used in the frame before the malleable rods 1108 are connected together by the connectors 1 1 10.

Once a frame of the desired shape and size has been constructed and disposed around the intended surgical site the surgeon may begin the procedure. When the surgeon requires a portion of tissue to be retracted he or she may select an elastic stay 1106 having an appropriate tissue engaging portion and they may hold the tissue in a desired position by engaging the tissue with the tissue engaging portion of the elastic stay, placing one of the cylindrical portions 1 172 of the elastic stem 1 168 in a recess 1 158, 1166 of a stay clamp or a connector clamp and then moving the cylindrical portion through the recess in an axial direction until a spherical stopper adjacent to the cylindrical portion engages the clamp and prevents further movement of the elastic stem through the recess. It will be understood that it is advantageous for the elastic stem to be held in tension when it is fixed relative to the frame 1102, as this causes the spherical stopper 1170 to firmly engage with the clamp and retains the tissue engaging portion in contact with the tissue. This substantially prevents further movement of the tissue relative to the elastic stay 1 106 or the frame 1102.

It will be understood that if a surgeon wishes to apply tension to a portion of tissue in a particular direction then one of the stay clamps 1 104 may be moved to an appropriate location to fix a retractor stay applying tension in the required direction in place relative to the frame 1102. This may be done by moving the lever 1 162 of the stay clamp 1 104 from its closed position to its open position, sliding the stay claim 1 104 along the malleable rod 1 108 on which it is located until it reaches the desired position, then returning the lever to the closed position. Once an elastic stay 1106 is in place with a spherical stopper engaging a stay clamp so as to prevent further movement of the elastic stay 1 106 relative to the stay clamp 1 104, a surgeon may perform fine adjustments to the tension in the elastic stay by rotating the stay clamp about the longitudinal axis of the malleable rod on which it is located. This may be performed by simply twisting the stay clamp so as to apply a torque sufficient to overcome the friction between the inner surface of the aperture 1 160 and the outer surface of the malleable rod 1108. Alternatively, the surgeon may move the lever 1 162 of the stay clamp to its open position, rotate the stay clamp 1 104 to the desired angular position on the malleable rod and then move the lever 1 162 back to its closed position. Larger adjustments to the tension in the elastic stay may be performed by removing the elastic stay from the recess and then placing a different one of the cylindrical portions 1172 in the recess. This causes the length of the elastic stay that is between the tissue portion and the stay claim 1 104 to change, thereby changing the tension in the elastic stay 1106.

It will be understood that during a given procedure a surgeon may retract several portions of tissue, and that retractors with different tissue engaging portions may be suitable for different portions of tissue. A particular advantage of the retractor system 1 100 of the present invention is that it provides a surgeon with significant flexibility as to where around a surgical site anchor points for retractor stays may be located. Because the malleable rods 1 108A, 1 108B may be readily reshaped it is possible to produce frames that are particularly well suited to the needs of an individual surgical procedure. Furthermore, as the connector clamps 11 12 are rotatably mounted on the connector bar 1 110, a surgeon producing a frame is not forced to produce a frame with the malleable rod meeting the connector at a specified angle. This significantly improves the flexibility of the system. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.

Claims

1. A surgical retractor system comprising:

a handle;

wherein:

said retaining member comprises a plurality of recesses, each recess defining a spherical seat and being arranged to allow a portion of the retractor stem to pass through the retaining member; and

the spherical seats are operable to engage the spherical stoppers, thereby limiting movement of the retractor stem through the retaining member.

2. A surgical retractor system as claimed in claim 1 and further comprising a clamp, said clamp being attachable to the retaining member, wherein:

the clamp comprises a clamp recess defining a clamp spherical seat;

the clamp spherical seat is operable to engage said spherical stoppers, thereby limiting movement of the retractor stem through the clamp.

3. A surgical retractor system as claimed in claim 2, wherein:

at each of said recesses said retractor stem is operable to pass through said retaining member in a direction perpendicular to a first surface, said first surface being a surface of the retaining member;

at said clamp recess said retractor stem is operable to pass through said clamp in a direction perpendicular to a second surface, said second surface being a surface of the clamp; and

when said clamp is attached to said retaining member said first surface is inclined relative to said second surface.

4. A surgical retractor system as claimed in claim 3, wherein said first surface is substantially perpendicular to said second surface when said clamp is attached to said retaining member.

5. A surgical retractor system as claimed in claim 1 , wherein said plurality of recesses comprises a first recess and a second recess, wherein:

said first surface is inclined relative to said second surface.

6. A surgical retractor system as claimed in any preceding claim, wherein said retaining member is arcuate.

7. A surgical retractor system as claimed in any preceding claim and comprising a plurality of said retaining members.

8. A surgical retractor system as claimed in claim 7, wherein each of said retaining members comprises a connecting portion, wherein each of said retaining members may be connected to said handle or another of said retaining members at said connecting portions.

9. A surgical retractor system as claimed in claim 7 or claim 8 wherein said plurality of retaining members comprises at least a first retaining member having a first number of recesses and a second retaining member having a second number of recesses, said second number being greater than said first number.

10. A surgical retractor system as claimed in any preceding claim, wherein said tissue engaging portion comprises a hook.

1 1. A surgical retractor system as claimed in any one of claims 1-9, wherein said tissue engaging portion comprises a retractor.

12. A surgical retractor system as claimed in any preceding claim and further comprising an articulated arm having a holding portion operable to hold said handle.

13. A surgical retractor frame comprising at least one malleable rod and at least one connector, wherein:

the connector comprises two connector clamps rotatably mounted on a connector bar, each connector clamp being arranged to receive and secure a portion of the malleable rod.

14. A surgical retractor frame as claimed in claim 13, wherein the plastics material comprises a natural or synthetic rubber.

15. A surgical retractor frame as claimed in claim 14, wherein the plastics material comprises silicone.

16. A surgical retractor frame as claimed in any preceding claim, wherein the stiffening portion comprises a metal wire.

17. A surgical retractor frame as claimed claim 16, wherein the stiffening portion comprises a coil of metal wire.

18. A surgical retractor frame as claimed in claim 17, wherein the stiffening portion comprises a plurality of coils of metal wire.

19. A surgical retractor frame as claimed in any one of claims 16-18 wherein the metal wire comprises SAE 304 stainless steel.

20. A surgical retractor frame as claimed in any preceding claim, wherein the plastics material is moulded over the stiffening portion.

21. A surgical retractor frame as claimed in any preceding claim, wherein at least the end portions of the malleable rod are cylindrical and wherein the each of the connector clamps has an annular portion arranged to receive at least an end portion of the malleable rod, the annular portion being switchable from an open state in which the annular portion has a minimum internal diameter greater than the diameter of the end portions of the malleable rod and a closed state in which the annular portion has a minimum internal diameter less or equal to than the diameter of the end portions of the malleable rod.

22. A surgical retractor frame as claimed in claim 21 , wherein the connector clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to the external diameter of the end portions of the malleable rod to a value less than the external diameter of the end portions of the malleable rod.

23. A surgical retractor system comprising a surgical retractor frame as claimed in any preceding claim and one or more stay clamps, each of the stay clamps being arranged to be secured to a portion of the malleable rod and defining at least one recess arranged to receive a portion of an elastic stay.

24. A surgical retractor system as claimed in claim 23, wherein the stay clamp comprises at least two of said recesses.

25. A surgical retractor system as claimed in claim 23 or claim 24, wherein the stay clamp has an annular portion arranged to receive at least a portion of the malleable rod, the annular portion being switchable from an open state in which the annular portion has an internal diameter greater than the diameter of the portion of the malleable rod and a closed state in which the annular portion has an internal diameter less than or equal to the diameter of portion of the malleable rod.

26. A surgical retractor system as claimed in claim 25, wherein the stay clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to the external diameter of the portion of the malleable rod to a value less than the external diameter of the portion of the malleable rod.

27. A surgical retractor system as claimed in claim 25 or claim 26, wherein the stay clamp comprises a lever, the lever being operable to switch the stay clamp between the open state and the closed state.

28. A surgical retractor system as claimed in any one of claims 23-27 and further comprising at least one elastic stay.

29. A surgical retractor system as claimed in claim 28, wherein the elastic stay comprises an elongate stem having a tissue engaging portion at an end thereof and a plurality of spherical stoppers spaced apart along a length of the elongate member.

30. A surgical retractor system as claimed in claim 29 wherein the tissue engaging portion is provided on an end piece of the elastic stay, the end piece being detachable from the elongate stem.

31. A surgical retractor system as claimed in claim 30, wherein the system comprises a plurality of interchangeable end pieces.

32. A clamp for a surgical retractor system comprising an annular portion being switchable from an open state in which the annular portion has a first internal diameter to a closed state in which the annular portion has a second internal diameter less than the first internal diameter,

the clamp further comprising a recess arranged to receive a portion of an elastic stay.

33. A clamp claim 32, wherein the clamp comprises a cam rotatable between a first position and a second position, wherein rotation of the cam from the first position to the second position causes the minimum internal diameter of the annular portion to reduce from a value greater than or equal to a first value to a value less than the first value.

34. A connecting portion for a surgical retractor system comprising two connector clamps rotatably mounted on a connector bar, each connector clamp being arranged to receive and secure a portion of a cylindrical malleable rod.

35. A connecting portion as claimed in claim 34, wherein the connector clamp is a clamp as claimed in claim 32 or claim 33.