WO2003017847A1

WO2003017847A1 - Surgical retractor

Info

Publication number: WO2003017847A1
Application number: PCT/EP2002/009524
Authority: WO
Inventors: Maged Hussien
Original assignee: Maged Hussien
Priority date: 2001-08-23
Filing date: 2002-08-23
Publication date: 2003-03-06
Also published as: GB0120410D0

Abstract

The present invention relates to an axillary clearance surgical device (10) which comprises a self retaining element (14), preferably having a pair of pivotal arms (48) which are moveable relative to one another, the arms (48) being adapted to hold apart the sides of a surgical incision, the surgical device (10) further comprising a substantially L shaped retractor (12) which is releasably mountable to the self retaining element (14), the retractor (12) operable to retract muscle and/or tissue during axillary clearance surgery, the surgical device (10) further being mountable to a support arm (16) which is itself secured to the operating table during the procedure, in order to maintain the surgical device (10) in the desired position.

Description

SURGICAL RETRACTOR

The present invention relates to an axillary clearance surgical device for use in axillary clearance surgery following complete mastectomy or breast conserving surgery.

Breast cancer is the most common cancer in women with an annual incidence of 20,000 new patients per year in the UK and an estimated worldwide incidence of a million new patients per year. Despite the fall in mortality in recent years, the incidence of the disease is rising and remains an important cause of death in women.

Breast cancer may be treated with a variety of surgical options, including removing the whole breast (complete mastectomy) or removing only the tumour and an area of normal tissue around it (breast-conserving surgery). Types of breast-conserving surgery include wide local excision or partial mastectomy, in which a small amount of surrounding normal tissue is removed, and quadrantectomy, in which a quarter of the breast is removed.

For patients with operable breast cancer, the main aim of surgery is to eradicate local disease, prevent local recurrence and determine the prognostic category so that subsequent adjuvant treatment can be tailored to maximize the chances of cure. The major prognostic factors are the tumour size, histological grade and axillary lymph node status, which is the single 'gold standard' against which all other factors should be compared. The lymph nodes drain lymph from the breast, and may be invaded by cancer cells in cases of breast cancer. Clinical examination of the axilla is unreliable, correlates badly with the true histological nodal status with both false-positive and false-negative results in up to one-third of cases. Therefore axillary surgery is required. The options for surgical treatment of the axilla range from sampling and limited axillary dissection to formal clearance and more recently sentinel node biopsy, which is still under trial. Although this subject remains a matter of intense debate, axillary node clearance is the accepted option by most breast surgeons and is the standard practice in most breast surgery units. It allows assessment of the number of histologically involved lymph nodes which help to stage the disease, predict prognosis, plan adjuvant treatment, eradicate local axillary disease and minimize the uncontrollable local recurrence in the axilla. It has also been suggested that the level of axillary metastases correlate with prognosis. Level 1 axillary clearance comprises removal of the fat containing the lymph nodes up to the level of the pectoralis minor muscle. Level 2 axillary clearance comprises level 1 clearance plus removal of the fat behind the pectoralis minor muscle. Level 3 clearance comprises level 1 and level 2 clearance plus removal of the fat above the pectoralis minor muscle up to the clavicle bone. Axillary clearance is an essential step in the treatment of breast cancer, as the number of involved lymph nodes can tell the prognosis of the disease, and whether patients need other forms of treatment. Such other forms of treatment include radiation therapy, chemotherapy, and hormonal therapy.

Data from the Memorial Sloan-Kettering study found that survival at 5 and 10 years was significantly poorer in patients with histologically positive nodes at level II or III than in patients with negative nodes or positive nodes at only level 1. Other series showed that once the total number of involved nodes is taken into consideration, the level of axillary involvement is not of independent prognostic significance. Few patients (3-5%) have lymph nodes involved at level II or III in the absence of level I involvement. Therefore level III clearance carries the best chance to cure and prevent any further local recurrence in the axilla.

Generally, axillary clearance is done at the same time as performing a total mastectomy or breast-conserving surgery. For axillary clearance to be complete, it has to be up to level 3 as hereinbefore described. Levels 2 and 3 of the axilla are in positions difficult for a surgeon to reach. The axilla is a potential pyramidal space consisting of four walls, an apex and a base. The anterior wall is formed by pectoralis major and minor muscles, the posterior wall by subscapularis and latissimus dorsi muscles, the medial wall by serratus anterior muscle and the lateral wall by the humerus and brachialis muscle. The base is formed by the axillary fascia deep to the skin of the axilla.

Axillary node clearance involves the removal of axillary tissue contained within the space between the axillary vein superiorly, latissimus dorsi muscle laterally and serratous anterior muscle medially. There are a number of important structures within the axilla which need to be identified and protected during the procedure. A number of anatomical variations in the axilla have been described and can be up to 29% of cases. Identification of the anatomy of the axilla is essential to avoid damage of these important structures. This requires a perfectly stable and properly lighted surgical field during the whole procedure.

In the prior art, it is known to use a retractor to retract the pectoral muscles, more particularly, the pectoralis minor muscle, so that level 2 and 3 axillary clearance can be completed. However, more than one assistant is generally required to hold the retractor in the desired position for a prolonged period of time. The assistants are necessary to (a) retract the skin edges around the operating area and (b) retract the pectoral muscles.

In the prior art, it is also known to use a Golligher retractor comprising a hook and chain. However, the hook employed is generally too short to retract the pectoral muscles effectively and the chain does not allow for adjustment of the hook. The hook and chain combination of the Golligher retractor can only show up to level 1 of the axilla. Therefore, the conventional method of reaching the level 2 and 3 axillae is to cut and divide the pectoralis minor muscle followed by retraction thereof by one or more assistants. This cutting and retraction then exposes the level 2 lymph nodes behind the pectoralis minor muscle and also exposes the level 3 axilla.

It is therefore an object of the present invention to mitigate one or more of the problems associated with performing axillary clearance surgery.

It is also an object of this invention to provide an improved surgical device for use in axillary clearance surgery.

It is a further object of the present invention to provide an axillary clearance surgical device which obviates the need for assistants to be present during axillary clearance surgery.

It is a still further object of the present invention to provide an axillary clearance surgical device which is adapted to aid in the training of junior doctors or the like in said axillary clearance surgery.

The present invention therefore provides an axillary clearance surgical device comprising a retaining element having a pair of arms movable relative to one another and adapted to hold apart the sides of a surgical incision; and a substantially L shaped retractor mountable to the retaining element, wherein the surgical device is, in turn, mountable to any suitable support.

Preferably, the retractor comprises an arm and a blade, the blade being elongate and substantially perpendicular to the arm.

Preferably, the free end of the blade terminates in a lip.

Preferably, the lip curves upwardly away from the blade. Preferably, the lip is disposed at an obtuse angle to the blade, preferably at an angle of between 120° and 150°, most preferably at an angle of 135°.

Preferably, the retractor comprises at least one light output.

Preferably, the retractor comprises two light outputs, a first output located along the blade, proximal the junction of the arm and the blade, and a second output located along the blade between the first output and the free end of the blade.

Preferably, the first output is arranged to radiate light at an angle away from the blade of the retractor.

Preferably, the first and second light outputs comprise optical fibre.

Preferably, the optical fibre is located internally of at least the arm of the retractor.

Preferably, the retaining element is a self retaining element adapted to hold the pair of arms in a given position following articulation of the arms into said position.

Preferably, the retaining element comprises a coupling for releasably mounting the retractor thereto.

Preferably, the self retaining element comprises a selectively operable locking means adapted to maintain a desired spacing between the pair of arms.

Preferably, the locking means comprises a pawl and ratchet provided with a release mechanism.

Preferably, each arm of the retaining element comprises a first section, and a second section hingedly mounted to the first section. Preferably, each second section is permitted to hinge, relative to the respective first section, in a plane generally orthogonal to the plane in which the pair of arms move relative to one another.

Preferably, each arm of the retaining element is provided with a foot mounted to the respective second section.

Preferably, at least the blade of the retractor is comprised of an electrically insulating material, or an electrically conductive material provided with a coating of electrically insulating material.

Preferably, a fibre optic camera may be provided in operative association with the retractor in order to permit the display or recording of a surgical procedure performed with the surgical device.

As used herein, the term "axillary" is intended to mean of or relating to the axilla, namely the cavity beneath the junction of the shoulder and the arm, which cavity contains the axillary vein and artery, a portion of the brachial plexus of nerves, a large number of lymph nodes, and fat and areolar tissue.

As used herein, the term "blade" is not intended to mean an implement or tool having a sharp or serrated edge suitable for cutting, but rather is intended to mean a substantially flat and thin part or plate which makes contact with muscle and/or tissue to perform a desired action, in particular the support and/or retraction of said muscle or tissue.

The present invention will now be described with reference to the accompanying drawings, in which; Figure 1 illustrates a perspective view of an axillary clearance surgical device according to the present invention, the surgical device being mounted within a support arm which is partially illustrated;

Figure 2 illustrates a schematic view of a torso of a human body, detailing the location of both the pectoralis major and pectoralis minor muscles;

Figure 3 illustrates a perspective view of a retractor forming part of the surgical device illustrated in figure 1 in addition to a perspective view of a portion of the retractor which has been enlarged for illustrative purpoes;

Figure 4 illustrates a perspective view of a self retaining element forming part of the surgical device illustrated in figure 1 ;

Figure 5 illustrates a partial perspective view of the rear of the self retaining element of figure 4, showing a coupling by which the retractor of figure 3 is releasably securable to the self retaining element;

Figure 6 illustrates a cross-section of that portion of the self retaining element shown in figure 5, the retractor of figure 3 being secured within the coupling; and

Figure 7 illustrates a perspective view of the surgical device of the present invention, mounted within the support arm which is itself secured to the side of an operating table, the surgical device being secured to a patient to facilitate axillary clearance surgery.

Referring now to the accompanying drawings, there is illustrated an axillary clearance surgical device, generally indicated as 10, for particular use in aiding a surgeon in performing axillary clearance surgery, which is conventionally a difficult and time consuming procedure, in particular as a result of the requirement for clearance of the lymph nodes in all three levels of axilla. The surgical device 10 essentially comprises a retractor 12 and a self retaining element 14 to which the retractor 12 is preferably releasably engagable, the surgical device 10 being mounted, in use, to a support in the form of a support arm 16 as shown in both figures 1 and 7, the advantages of which will become apparent from the following description of the invention.

Referring to figure 2, there is illustrated a schematic view of a torso of a human body 18, showing, in particular, the position and orientation of a pectoralis minor muscle 20 and a pectoralis major muscle 22, in addition to a clavicle 24, a sternum 26, and a humerus 28 of an arm 30. In conducting axillary clearance surgery, in order to gain access to the relevant areas surrounding the pectoralis minor muscle 20, an incision 32 (shown in figure 7) is cut, through which incision 32 access to the axilla is gained. The surgical device 10 is adapted, as will be described in greater detail hereinafter, to draw and maintain apart sides 34 of the incision 32, and to retract the pectoralis minor muscle 20 and the pectoralis major muscle 22, in order to facilitate axillary clearance.

Referring now to figure 3, the retractor 12, in the preferred embodiment illustrated, comprises an elongate arm 36 mounted to one end of which is a blade 38, both of which are preferably formed from stainless steel, although it will of course be appreciated that any other material having the requisite properties may be used, namely being chemically inert and having sufficient rigidity to perform the necessary retraction, examples of such material being aluminium, carbon fibre, etc. The blade 38 is preferably permanently secured to the arm 36 in order to provide structural rigidity to the retractor 12, although it is also envisaged that the blade 38 could be releasably secured to the arm 36 in order to permit blades (not shown) of varying shape and configuration to be mounted to the arm 36. It will also be appreciated that the arm 36 need not be cylindrical as shown, and could alternatively be substantially flattened in one plane, or of any other suitable shape. In addition, although in the preferred embodiment illustrated, the arm 36 and blade 38 are disposed at approximately 90° to one another, this angle could of course be varied to suit particular surgical conditions.

The blade 38 is also provided with a lip 40 at the free end thereof, which lip 40 forms an obtuse angle with the blade 38, preferably of between 120° and 150°, and most preferably 135°. The lip 40 is intended to provide increased upward retraction, in use, of the pectoralis minor muscle 20 in order to enlarge the operative space generated by the retractor 12 at the free end thereof, in order to increase visibility and thus improve the performance of the surgical device 10. In addition, the blade 38 is preferably relatively narrow, in particular with reference to its length, in order to permit the incision 32 to be reduced in dimension, while still permitting the insertion and operation of the retractor 12, in particular for cosmetic and healing purposes. In a particularly preferred embodiment, the blade 38 is approximately 150mm in length and 25mm in width, although it will of course be appreciated that the invention is not limited to the blade 38 having the above dimensions.

The retractor 12 is further provided with a light output in the form of a optical fibre 42, which in the preferred embodiment illustrated is located internally of the arm 36, and at the end of the arm 36 secured to the blade 38, is split into a first branch 44 and a second branch 46, as clearly illustrated in figure 3. The location and orientation of both the first and second branches 44, 46 has been carefully chosen to provide the optimum illumination to, in use, the operative space formed by the surgical device 10. The level 1 axilla is located, in use, just beyond the incision 32, and the first branch 44 therefore terminates at or adjacent the junction between the arm 36 and the blade 38, as clearly illustrated in figure 3. In addition, as the level 1 axilla is located, in use, beneath the blade 38, the free end of the first branch 44 is preferably permanently angled downwardly away from the blade 38 as shown in the enlarged portion of the retractor 12 shown in figure 3, such as to radiate light at an angle away from the blade 38 in order to fully illuminate the level 1 axilla. However, as the level 2 and 3 axilla are deep within the operative space produced by the surgical device 10, the second branch 46 extends beneath and parallel to the blade 38, terminating approximately halfway along the length of the blade 38. The free end of the second branch 46 is directly substantially parallel to the blade 38, such as to illuminate the area about and beyond the lip 40. Thus it will be appreciated that the provision of at least two separate light outputs renders visible the entire operative space for the entire duration of the axillary clearance surgery. It will be appreciated that the complete illumination of the operative space during axillary clearance surgery reduces the operating time, and consequently the anestethic time, and in addition will reduce the incidents of trauma to important structures in the axilla, by enabling the immediate identification of same, and thus the avoidance thereof.

Referring now in particular to figures 1, 4 and 7, the self retaining element 14 forms an integral part of the surgical device 10, being used in conjunction with the retractor 12 to simplify axillary clearance surgery. The primary purpose of the self retaining element 14 is to hold open the sides 34 of the incision 32, in order to allow access by the surgeon. The self retaining element 14 is therefore provided with a pair of arms 48 which are preferably pivotally mounted to one another about a pivot 50. Each arm 48 has a ring 58 disposed at one end thereof, for receiving the fingers of the surgeon, and a leg 60 hmgedly mounted at the opposed end thereof. It will therefore be appreciated that in advancing the pair of rings 58 towards one another, the pair of legs 60 will be forced outwardly away from one another, in scissors-like fashion. Each leg 60 includes a foot 64 mounted thereto by means of a pivot 66, each foot 64 engaging, in use, one side 34 of the incision 32, as illustrated in figure 7, in order to hold open said incision 32. Therefore, in order to permit the pair of legs 60 to be forced outwardly away from one another, and maintained in this position, the self retaining element 14 is provided with a pawl 52 and a correspondingly shaped and dimensioned ratchet 54, each of which being located on an opposite leg 48, proximal the pair of rings 58. The configuration and operation of the pawl 52 and the ratchet 54 permit the pair of rings 58 to be advanced towards one another, thereby drawing apart the pair of legs 60, but prevent movement in the return direction, in conventional fashion. Thus, once the sides 34 of the incisions 32 have been opened a sufficient distance for the performance of axillary clearance surgery, the surgeon simply withdraws his fingers from the rings 58, wherein the pawl 52 and the ratchet 54 maintain the pair of legs 60 in position as shown in figure 7.

In the event that the pair of legs 60 require re-positioning, or indeed where the self retaining element 14 is required to be released following the completion of surgery, a release mechanism 56 is provided in operative association with the pawl 52, whereby upon depression of the release mechanism 56 towards the corresponding ring 58, the pawl 52 is lifted out of engagement with the ratchet 54, thereby allowing the pair of arms 48 to close.

In order to provide greater scope for the positioning of the self retaining element 14, each leg 60 is secured to the respective arm 48 by a hinge 62, which therefore allows the position of each leg 60 to be altered relative to the corresponding arm 48, as can be seen in figure 7. However, it will be noted that the orientation of each hinge 62 is such that each leg 60 is only capable of movement within a plane which is generally orthogonal with the plane within which the pair of arms 48 move. Were the pair of legs 60 capable of movement within the same plane as the pair of arms 48, the pair of legs 60 would simply hinge inwardly towards one another as the pair of legs 48 were forced away from one another, thereby preventing the incision 32 from being adequately opened.

It will be appreciated from the foregoing description of the operation of the self retaining element 14 that the intended function thereof is in drawing apart the opposed sides 34 of the incision 32, and maintaining the sides 34 in an opened position. Thus it will be appreciated that the particular configuration of the self retaining element 14 is not of particular importance, once the above function is performed. Therefore, it is not necessary that the pair of arms 48 be pivotally mounted to one another, or indeed that the self retaining element 14 comprise the pair of arms 48. Any other suitable linkage (not shown) or arrangement could also be used, once the function of opening the sides 34 of the incision 32 may be achieved. It must however be borne in mind that it is necessary that the self retaining element 14 provides, in use, clear access through the incision 32.

Turning to figures 5 and 6, it can be seen that the self retaining element 14 is provided with a coupling 68 which, in the preferred embodiment illustrated, is provided as a split ring into which the arm 36 of the retractor 12 is pressed, and gripped, such as to retain the retractor 12 in position relative to the self retaining element 14. It will of course be appreciated that any other suitable means (not shown) could be substituted for the coupling 68, in order to adequately secure the retractor 12 to the self retaining element 14. Alternatively, the retractor 12 could be permanently secured to the self retaining element 14 by any suitable means, although it will of course be appreciated that it is preferable that the retractor 12 be releasably mountable to the self retaining element 14, in order to enable interchangability.

Referring now to figures 1 and 7, and as hereinbefore described, in order to secure the surgical device 10 in position during axillary clearance surgery, the surgical device 10 is adapted to be clamped by the support arm 16, which is itself rigidly secured to an operating table 82 on which the patient is disposed. The support arm 16 comprises a main clamp 70, as clearly seen in figure 1, which main clamp 70 is adapted to engage the arm 36 of the retractor 12, such as to grip the surgical device 10. The main clamp 70 is connected to one end of a first rod 72, an opposed end of which is connected to a central clamp 74, from which extends a second rod 76. The central clamp 74 is operable to alter the angle between the first rod 72 and the second rod 76. The second rod 76 is itself secured to a column 78, which is connected to a table clamp 80 operable to secure the support arm 16 to the operating table 82. Thus the support arm 16 permits the surgical device 10 to be accurately positioned as required, and to then be locked in the desired position for the entire duration of the axillary surgery. Thus it will be appreciated that once the surgical device 10 is positioned in the desired location, the incision 32 adequately opened, and the retractor 12 positioned such as to retract the pectoralis minor muscle 20 and the pectoralis major muscle 22, the surgeon does not require any assistance, thus reducing staffing requirements for this operation, or alternatively any assistant present is kept free to aid the surgeon as required.

The surgical device 10 of the present invention further enables a conventional fibre optic camera (not shown) or the like to be secured to the blade 38, in order to record the entire surgical procedure, with a particular view to training junior doctors or the like.

It is also preferable that at least the blade 38 of the retractor 12, and preferably the entire retractor 12, is provided with a coating of electrically insulating material, in order to permit the use of diathermy during the surgical procedure, while preventing accidental electrocution of the patient. The coating may be of any conventional form, but is preferably a plastic or ceramic coating. As an alternative to the electrically insulating coating, it is also envisaged that the blade 38, or indeed the entire retractor 12, could be formed entirely from an insulating material such as a ceramic or the like.

Therefore, in use, the patient is placed supine with the arm 30 abducted to 90° on a sideboard (not shown), therefore obviating the need to drape the forearm as is generally done in conventional axillary clearance surgery. The incision 32 is then made transversely, which should remain posterior to the lateral edge of the pectoralis major 22. This gives the most acceptable cosmetic outcome, and in conjunction with the use of the retractor 12, provides an adequate exposure. The sides 34 of the incision are then raised to the lateral edge of the pectoralis major 22, which is then freed to allow the use of the retractor 12. The retractor 12 is then used to retract the pectoralis major 22 upwards and medially. The self retaining element 14 is then used to retract the sides 34 and maintain the entry to the operative space during the entire surgical procedure. The fibre optic cable 42 is then connected to a suitable light source (not shown).

The lateral edge of the pectoralis major 22 is now dissected superiorly and inferiorly as much as the incision 32 allows. The interpectoral fat and the contained lymph nodes between the pectoralis major 22 and the pectoralis minor 20 are removed. Damage to the lateral pectoral nerve and vessels should be avoided during this step. The pectoral nerve supplies the costal fibres of the pectoralis major 22 and lateral fibres of the pectoralis minor 20. Denervation of these muscle fibres will result in avoidable disfiguring concavities. The sides 34 are dissected inferiorly to the lateral edge of the lattisimus dorsi muscle, exposing the junction of its muscular and tendonous parts, which serves as the anatomical marker of the axillary vein. The axillary vein is identified and the fatty tissue is cleared from it anterior and inferior aspects, working towards the apex of the axilla. It is now possible to sweep the contents of the axilla away from the lateral chest wall. The long thoracic nerve is identified and preserved at this stage. The long thoracic nerve lies just laterally of the facia of the axillary contents as it is pulled away from the chest wall. This facia is incised and the long thoracic nerve freed and protected.

The axillary contents can be swept downwards from the axillary vein with ligation and division of a small superficial unnamed tributary. The sub scapular vessels can be identified inferior to this tributary with the thoracodorsal nerve lying medial to the sub scapular vessels. This nerve should be dissected and traced throughout its course to the litisimus dorsi muscle. Alternatively the nerve can be identified distally and traced upwards. It is possible to now remove the axillary contents and this will complete level 1 clearance.

The pectoralis minor 20 is now dissected and the retractor 12 position is adjusted to retract this muscle with the pectoralis major 22, exposing the level 2 and 3 axilla. The second branch 46 now provides a perfect view of the level 2 and 3 axilla. Axillary fat with the contained lymph nodes in level 2 and 3 are dissected off the axillary vein and removed up to the level of the costoclavicular ligaments. This step therefore completes level 3 axillary node clearance.

Thus it will be appreciated that the surgical device 10 of the present invention provides a number of advantages over conventional axillary clearance surgery, reducing both operative and anestethic time, while increasing the accuracy of such surgery.

Claims

1. An axillary clearance surgical device comprising a retaining element having a pair of arms moveable relative to one another and which are adapted to hold apart the sides of a surgical incision; and a substantially L shaped retractor mountable to the retaining element, wherein the surgical device is, in turn, mountable to any suitable support.

2. A surgical device according to claim 1 wherein the retractor comprises an arm and a blade, the blade being elongate and substantially perpendicular to the arm.

3. A surgical device according to claim 2 wherein the free end of the blade terminates in a lip.

4. A surgical device according to claim 3 wherein the lip curves upwardly away from the blade.

5. A surgical device according to claim 3 wherein the lip is disposed at an obtuse angle to the blade, preferably at an angle of between 120° and 150°, most preferably at an angle of 135°.

6. A surgical device according to any preceding claim wherein the retractor comprises at least one light output.

7. A surgical device according to claim 6 wherein the retractor comprises two light outputs, a first output located along the blade, proximal the junction of the arm and the blade, and a second output located along the blade between the first output and the free end of the blade.

8. A surgical device according to claim 7 wherein the first output is arranged to radiate light at an angle away from the blade of the retractor.

9. A surgical device according to claim 7 or 8 wherein the first and second light outputs comprise optical fibre.

10. A surgical device according to claim 9 wherein the optical fibre is located internally of at least the arm of the retractor.

11. A surgical device according to any preceding claim wherein the retaining element is a self retaining element adapted to hold the pair of arms in a given position following articulation of the arms into said position.

12. A surgical device according to any preceding claim wherein the retaining element comprises a coupling for releasably mounting the retractor thereto.

13. A surgical device according to claim 11 or claim 12 when dependant on claim 11, wherein the self retaining element comprises a selectively operable locking means adapted to maintain a desired spacing between the pair of arms.

14. A surgical device according to claim 13 wherein the locking means comprises a pawl and ratchet provided with a release mechanism.

15. A surgical device according to any preceding claim wherein each arm of the retaining element comprises a first section, and a second section hingedly mounted to the first section.

16. A surgical device according to claim 15 wherein each second section is permitted to hinge, relative to the respective first section, in a plane generally orthogonal to the plane in which the pair of arms move relative to one another.

17. A surgical device according to claim 15 or 16 wherein each arm of the retaining element is provided with a foot mounted to the respective second section.

18. A surgical device according to any of claims 2 to 17 wherein at least the blade of the retractor is comprised of an electrically insulating material, or an electrically conductive material provided with a coating of electrically insulating material.

19. A surgical device according to any preceding claim wherein a fibre optic camera may be provided in operative association with the retractor in order to permit the display or recording of a surgical procedure performed with the surgical device.