Various retractors are known. However in general known retractors are difficult and cumbersome to use, and/or are relatively complex and consequently expensive.

This invention is directed towards providing an improved wound retractor which will overcome at least some of these problems.

Statements of Invention According to the invention there is provided a surgical wound retractor comprising: an inner anchoring ring for insertion into a wound opening to be retained inside the wound opening; an outer retracting means for positioning outside of the wound opening; and a connecting member extending between the anchoring ring and the retracting means,

the connecting member having an inner wound engaging portion and an outer portion, at least the inner wound engaging portion having an insertion configuration with a reduced radial dimension and a retracting configuration, the outer portion of the connecting member being pulled laterally by the outer retracting means to urge the wound engaging portion to the retracting configuration.

In a preferred embodiment of the invention the outer retracting means comprises a ring having a larger diameter than that of the inner anchoring ring.

Preferably the outer retracting means is biased to urge the connecting member into the retracting configuration.

In one embodiment the retracting means is of a semi-rigid material. The retracting means may also be at least partially of a shape memory material such as nitinol. In one embodiment the retracting means comprises a ring.

In a preferred embodiment at least the wound engaging portion of the connecting member is of generally cylindrical shape.

Alternatively at least the wound engaging portion of the connecting member is of generally conical shape.

In a preferred embodiment at least the outer portion of the connecting member has a lateral component. Preferably at least the outer portion of the connecting member is of generally conical shape.

In one particularly preferred embodiment the retracting means includes an inflatable chamber. The inflatable chamber is preferably provided on at least portion of the connecting member. In one arrangement the inflatable chamber is provided on the outer portion of the connection member. In another arrangement the inflatable chamber is provided on the inner and outer portions of the connecting member.

In one embodiment the retractor includes retaining means for retaining the outer portion of the connecting member substantially flat in the region surrounding the wound opening. The retaining means may comprise a release adhesive or the retaining means comprises a clamp.

Preferably the connecting member is of pliable material. Ideally the connecting member is of a plastics material. In one embodiment the connecting member is of an elastic material.

The anchoring ring is preferably of flexible material.

In another aspect the invention provides a method for retracting a surgical wound using a surgical retractor comprising an inner anchoring ring, an outer retracting means and a connecting member extending between the inner anchoring ring and the outer retracting means, the connecting member having an insertion configuration with a reduced radial dimension and a retracting configuration, the connecting member further having an inflatable chamber thereon, the method comprising the steps of :- gripping the inner anchoring ring and the wound engaging portion of the connecting means to move the anchoring ring and the connecting means into an insertion configuration in which the wound engaging portion of the connecting member has a reduced radial dimension;

releasing the anchoring ring inside the wound opening to retain the anchoring ring inside the wound opening; and inflating the chamber to urge the wound engaging portion into the retracting configuration.

Brief Description of the Drawings The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings, in which:- Fig. 1 is a perspective view from below of a wound retractor according to the invention; Fig. 2 is a side cross sectional view of the retractor of Fig. 1; Figs. 3 (a) to 3 (c) are perspective views of the retractor of Fig. 1 in use; Fig. 4 is a side cross sectional view of the retractor of Fig. 1 in the position of Fig. 3 (c); Fig. 5 is a perspective view from below of another wound retractor according to the invention; Fig. 6 is a side cross sectional view of the retractor of Fig. 5; Fig. 7 is a perspective view from below of another wound retractor according to the invention; Fig. 8 is a side cross sectional view of the retractor of Fig. 7;

Fig. 9 is a perspective view from above of another wound retractor according to the invention ; Fig. 10 is a plan view of the retractor of 9 ; Fig. 11 is a cross sectional view along the line A-A in Fig. 10; Figs. 12 to 14 are side cross sectional views of the retractor of Figs. 9 to 11 in use; Fig. 15 (a) is a perspective view from above of another wound retractor according to the invention in an uninflated configuration; Fig. 15 (b) is a perspective view from above of the retractor of Fig. 15 (a) inflated; and Fig. 15 (c) is a partially cut away perspective view of the retractor of Figs.

15 (a) and 15 (b) in use.

Detailed Description Referring to the drawings and initially to Figs. 1 to 4 thereof, there is illustrated a surgical wound retractor 1 according to the invention, which is used to retract the margins of an incision such as an abdominal wound opening 2, as illustrated in Figs. 3 (a) to 3 (c).

The retractor 1 comprises an inner anchoring ring in the form of an inner O-ring 6 of flexible material for insertion into the wound opening 2 to be retained in the wound opening 2, and an outer retracting means, in this case in the form of an outer O-ring 7. The outer ring 7 is of a larger diameter than, and of a material

which is rigid relative to, the inner O-ring 6, for positioning outside the wound opening 2. A connecting member in the form of a sheet 9 of pliable plastics material extends between the inner ring 6 and the outer ring 7 to retract and protect the wound opening 2.

The sheet 9 has an inner wound engaging portion, in this case provided by a distal substantially cylindrical sleeve portion 10 attached to and extending from the inner O-ring through the wound opening 2, and an outer portion, in this case provided by a proximal conical sleeve portion 11 extending from the distal sleeve portion 10 out of the wound opening 2 to the outer ring 7, to which the sleeve portion 11 is attached. The distal sleeve portion 10 has an insertion configuration with a reduced radial dimension and a retracting configuration.

In use the inner O-ring 6 and the distal sleeve portion 10 are scrunched up to form the insertion configuration and the inner O-ring 6 is inserted into the wound opening 2, as illustrated in Figs. 3 (a) and 3 (b). On release of the inner O- ring 6, the O-ring 6 overlaps the inner edge of the wound opening 2 to provide a secure anchoring of the retractor 1 in the wound, and the outer O-ring 7 is biased into a distorted non-planar shape due to the compressive forces exerted on the sheet 9 by the margins of the wound.

The proximal sleeve portion 11 is then pulled laterally by flattening out the outer O-ring 7 into its normal O-shape around the wound opening 2. On flattening, the distal sleeve portion 10 is pulled into the retracting configuration which retracts the wound opening 2 laterally, as illustrated in Figs. 3 (c) and 4.

To retain the proximal sleeve portion 11 in the flattened out wound retracting configuration any suitable retaining means such as a clamp may be used.

Alternatively or additionally a releasable adhesive may be used to bond the sleeve portion 11 to a fixture and/or to the skin around the wound opening 2.

In the retracted configuration the distal sleeve portion 10 lines the side of the wound opening 2 thereby protecting the exposed tissue of the wound margins, as illustrated in Figs. 3 (c) and 4.

The invention provides a surgical wound retractor of simple construction which is easy to use and can be manufactured inexpensively to provide a disposable unit.

The wound retractor according to the invention may be used to maintain a wound in a retracted configuration indefinitely without requiring intervention by a clinician to prevent closure of the wound opening.

A portion of the connecting member extends proximally out of the wound opening in use. Thus the retractor is suitable for use with a range of incision sizes and patient anatomies.

Referring to Figs. 5 and 6 there is illustrated another wound retractor 20 according to the invention which is similar to the retractor 1 of Figs. 1 to 4 and like parts are assigned the same reference numerals in Figs. 5 and 6. In this case the inner wound engaging portion is provided by a distal cylindrical sleeve portion 21 which is relatively short, and the outer portion is provided by a proximal disc-shaped sleeve portion 22. In use the retractor 20 operates in a manner similar to the retractor 1 of Figs. 1 to 4.

Referring to Figs. 7 and 8 there is illustrated a further wound retractor 30 according to the invention which is similar to the retractors 1,20 of Figs. 1 to 6 and like parts are assigned the same reference numerals in Figs. 7 and 8. In this case the sleeve 9 comprises a single disc-shaped portion 31 of elastic material. In use the inner O-ring 6 is inserted into the wound opening 2 and pulled so that part of the sleeve 9 extends through the wound opening 2 to form the inner

wound engaging portion and part extends out of the wound opening 2 to form the outer portion by virtue of the elasticity of the sleeve. The outer portion is pulled laterally to retract the wound opening 2 as described previously with reference to Figs. 1 to 4.

Referring to Figs. 9 to 14 there is illustrated another wound retractor 40 according to the invention which is similar to the retractor 1 described with reference to Figs. 1 to 4 and like parts are assigned the same reference numerals in Figs. 9 to 14.

In this case the inner wound engaging portion is provided by a distal conical sleeve portion 41 of pliable material attached to and extending from the inner O- ring 6 through the wound opening 2. The outer portion is provided by a proximal inner sheet 42 of pliable material and a proximal outer sheet 43 of pliable material sealed between the distal sleeve portion 41 and the outer O-ring 7 in spaced-apart relation to define a chamber 44 therebetween, as illustrated in Fig. 11. An inflation port 45 is provided on the inner sheet 42 for inflation of the chamber 44. The outer portion has a generally conical shape.

In use the inner O-ring 6 is inserted into the wound opening 2, as illustrated in Figs. 12 (a) and 12 (b) and as described previously with reference to Figs. 1 to 4, and the compressive forces exerted on the distal sleeve portion 41 by the margins of the wound act to collapse the sleeve. The proximal sheets 41,42 are pulled laterally by flattening out the outer O-ring 7 into its normal O-shape around the wound opening 2 to cause a primary partial retraction of the wound opening 2, as illustrated in Fig. 13. As may be seen from Fig. 13 the distal sleeve portion 41 remains in partial compression after this primary retraction.

The chamber 44 is then inflated to pull the distal sleeve portion 41 laterally and thereby urge the distal sleeve portion 41 into the retracted configuration, as

illustrated in Fig. 14. The inflation of the chamber 44 will maintain the wound opening 2 retracted without requiring additional retaining means.

An additional advantage of this embodiment is that by altering the pressure in the inflation chamber the retraction force exerted on the margins of the wound may be easily and accurately controlled to suit a particular incision size, a patient anatomy or a surgical procedure to be performed.

It will be appreciated that part of the outer portion of the sleeve may extend through the wound opening 2 after insertion of the inner O-ring 6.

The conical shape of the outer portion ensures that in the inserted, uninflated configuration of fig. 13, the proximal sheets 41,42 are wrinkled. Inflation of the chamber 44 is possible without stretching the material of the proximal sheets 41, 42 and thus there is no resistance to the distal sleeve portion 41 moving laterally to cause retraction of the wound opening 2.

Referring to Figs. 15 (a) to 15 (c) there is illustrated another wound retractor 50 which is similar to those described above. In this case an inner sheet 52 and an outer sheet 53 are sealed between the rings 6,7 in spaced apart relation to define an inflatable chamber 51 therebetween, as illustrated in Fig. 15 (c). An inflation port 54 is provided in the inner sheet 52 for inflation of the chamber 51. In use a distal portion of the inflatable chamber 51 extends through the wound opening 2 to form the wound engaging portion and a proximal portion extends laterally around the wound opening 2 to form the outer portion, and inflation of the chamber 51 causes retraction of the wound opening 2, as illustrated in Fig. 15 (c).

It will be appreciated that inflation may be used as at least portion of the retraction means for achieving lateral retraction of the wound opening in any of the devices of the invention.

The wound retractor may be constructed in any annular shape. For example the inner and outer rings may be oval, elliptical or circular.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.