WO2007129043A1

WO2007129043A1 - Suture clip

Info

Publication number: WO2007129043A1
Application number: PCT/GB2007/001604
Authority: WO
Inventors: Michael John Hawker; Michael Oakes
Original assignee: Surgi-Call Limited
Priority date: 2006-05-03
Filing date: 2007-05-03
Publication date: 2007-11-15
Also published as: GB0608671D0

Abstract

A suture clip (42) comprises a receiving member (20) and an insertion member (28). The receiving member (20) has a channel (30) for receiving a suture thread (4), and a passage (26) within which the insertion member (28) may be adjusted by means of an externally-applied force between a first position in which a suture thread (4) may be inserted into or removed from the passage (26), and a second position in which the insertion member (28) will prevent removal of a suture thread (4) from the receiving member (20). The insertion member (28) and the receiving member (20) are provided with interengagable features (36,46) which when interengaged will resist adjustment of the insertion member (28) from the second position.

Description

SUTURE CLIP

FIELD OF THE INVENTION

This invention relates to a suture clip for securing a suture.

BACKGROUND OF THE INVENTION

In recent years, advances in endoscopic and laparoscopic (keyhole) surgery have greatly reduced the invasiveness of surgical procedures. A small opening is made in a body cavity and an endoscope inserted to allow illumination and viewing of a site where surgery is required. One or more additional small openings are used to permit a surgeon to insert suitable instruments for carrying out the surgical procedure and suturing traumatised tissue.

Preferably, an incision of no more than 10 mm is made for an endoscopic camera, and incisions of no more than 5 mm diameter for suturing instruments or apparatus. A well known problem in performing keyhole surgery is that of securing a suture after a wound has been sutured. Suture knots are difficult to tie when working through small openings of the order of 5-10 mm diameter. In response to this problem, various attempts have been made to provide clips which can be applied to a suture thread to replace a suture knot. The suture clip should be easy to apply, and should provide an adequate pullout strength (the force needed to displace the clip from the suture thread). Thinner suture threads have lower pullout strengths than thicker suture threads. Recommended minimum standards or guidelines for pullout strength of sutures using suture threads in the most common gauges range from 7.4 newtons (0.2 mm diameter) to 22.3 newtons (0.4 mm diameter). Other desirable features are that the clip should be biodegradable and should not cause undue irritation at the wound site where the suture is applied. It is desirable that the suture clip should sit as flat as possible at the wound site, and distribute pressure evenly across the footprint of the clip to reduce trauma to the tissue. FR 2 262 867 describes a suture clip which comprises an insertion member and a receiving member. The insertion member has a channel for receiving one or more suture threads. When the insertion member is fully inserted in the receiving member, a suture thread in the insertion member is held within the clip. However, this arrangement has a relatively low pullout strength. EP O 634 142 describes a clip which works in a similar manner, but which includes improved engagement means for retaining the insertion member, and a retaining notch such that when the insertion member is retained in the receiving member one or more suture threads may be placed in the channel in the insertion member. In both types of clip, the suture thread is laterally displaced with respect to the wound site, and does not present a symmetrical footprint to the wound. We have found that, because the suture will be positioned to one side of the clip, the clip will tend to tilt to one side when the suture is tensioned. Tilting may cause the pressure on the tissue site to be localised across an edge or even a corner of the clip.

An alternative suture clip which does present a symmetrical footprint to a wound is disclosed in WO 00/61012. The clip comprises a radially-symmetrical body having an upper tubular portion and a flared lower portion. A loop of suture thread is passed axially through the clip and the tubular portion is crimped so that the crimped sides of the tubular portion engage the suture thread. A problem with this arrangement is that it is difficult to achieve sufficiently high pullout strength by crimping.

Another alternative suture clip is described in WO 2004/024006. The clip has a clamshell configuration comprising two half shells hinged together and fastenable about a suture thread by interengagable means that provide a snap fit. We have found that this design does not provide sufficient pullout strength when the clip is formed from a biodegradable polymer material.

SUMMARY OF THE INVENTION

According to an aspect of the present invention there is provided a suture clip comprising a receiving member and an insertion member; the receiving member having a channel for receiving a suture thread, and a passage within which the insertion member may be adjusted by means of an externally-applied force between a first position in which a suture thread may be inserted into or removed from the passage, and a second position in which the insertion member will prevent removal of a suture thread from the receiving member; the insertion member and the receiving member being provided with interengagable features which when interengaged will resist adjustment of the insertion member from the second position.

By locating a suture thread in a channel in the receiving member, and locking the thread in place with the insertion member, the clip may be secured to the suture thread with a pullout strength which meets or exceeds the guidelines when formed from a biodegradable plastics material. The clip may have a symmetrical footprint which will be located evenly over a tissue site when the channel is in the middle of the receiving member. The thread extending from the suture to a face of the clip may remain at substantially the same angle to that face, preferably about 90°, after the insertion member has locked the thread in place, thereby reducing tilting forces on the clip when in use.

Preferably, the clip has a footprint of length and breadth each in the range 2-5 mm, notably about 3-4 mm. The footprint of the clip is preferably square, optionally with rounded edges, or circular. In a preferred embodiment, the clip measures 2.5 mm x 3.5 mm. However, it will be understood that other footprint shapes are possible within the scope of the invention.

The insertion member need only be pushed into the receiving member to effect securing of the suture clip to the suture thread. When the insertion member is in the second position it is preferred that substantially no part of the insertion member projects outside the receiving member, to minimise the size of the clip when in use. During the locking process, the receiving member can readily be held still relative to the sutured tissue while the suture is suitably tensioned. The term 'thread' is used herein to refer to any material used for suturing. The thread may be monofilament or braided, and is preferably formed from a biodegradable material. Typically, a surgeon will suture using a loop of suture thread attached to a needle, so that the channel in the receiving member will receive two portions of thread.

The channel could be contained within the receiving member, between two holes, so that the thread is threaded in through one hole and out through the other. However, to facilitate location of the clip on the thread it is preferred that the channel is open along its length so that the thread can be laid in the channel by lateral insertion. The channel is preferably substantially straight so as further to facilitate insertion of the thread. To provide substantially even pressure on sutured tissue, it is particularly preferred that the receiving member is substantially symmetrical about a plane through the channel.

The insertion member may be locked in the receiving member by any suitable interengagable features, for example one or more barbs and notches, shoulders or other recessed portions. In a preferred embodiment, the insertion member will move a portion of the suture thread out of the channel and into the passage, where it is retained by the insertion member.

Accordingly, another aspect of the present invention provides a suture clip comprising a receiving member and an insertion member; the receiving member having a channel for receiving a suture thread, and a passage within which the insertion member may be adjusted by means of an externally-applied force between a first position and a second position; the insertion member and the receiving member being provided with interengagable features which when interengaged will resist adjustment of the insertion member from the second position; wherein adjustment of the insertion member from the first position to the second position when a suture thread is located in the channel will cause the insertion member to move a portion of the suture thread into the passage and retain a portion of the suture thread within the passage so as to prevent or inhibit its removal from the receiving member.

Although it would be possible to manufacture the receiving member and the insertion member separately, and optionally to pre-assemble them prior to use, it is preferred that the entire clip is integrally formed from a single material, for example as a one-piece moulding. The clip may be moulded so that the insertion member is located in the first position, attached to the receiving member by a thin web of material. When an external force is applied, for example by a suitable applicator instrument, the web is broken and the insertion member is adjusted to the second position. In a preferred embodiment, the insertion member is slidable in a straight line between the first and second positions. However, it would also be possible to adjust the insertion member by pivoting or rotation, or by sliding along a curved path. The invention will be described hereinafter with reference to this preferred embodiment.

The insertion member may be of any suitable shape and configuration to perform its function. In a preferred embodiment, the insertion member is substantially symmetrical about a central plane. It is particularly preferred that the insertion member is generally U-shaped or C-shaped, with the free ends projecting outside the receiving member when the insertion member is in the first position.

Each suture clip may be provided and used separately, but it is preferred that a plurality of clips are provided in a cartridge from which they may be serially dispensed. The cartridge may be mounted in a suitable applicator for dispensing clips and locking them to a suture thread.

The suture clip may be used in open surgery and in endoscopic or laparoscopic surgery.

Accordingly, a further aspect of the invention provides a method of suturing comprising providing a closed loop of suture material with a leading part for attachment to a needle and a trailing part, passing the leading part through or around tissue to be sutured and then through the trailing part of the loop, tensioning the suture material so that the leading and trailing parts engage, and applying to the suture material a suture clip as herein described to hold the suture material under tension.

The leading part may be passed through or around the tissue a number of times to form a running lock suture, prior to application of the clip. It will be appreciated that a looped suture brought onto itself over tissue and under tension will be in direct and firm contact at the point of engagement as long as the tension in the suture material is maintained.

Further aspects and benefits of the invention will appear in the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described, by way of example, with reference to the following drawings in which:

Figures 1-3 illustrate a suturing technique using an aspect of the present invention;

Figures 4 and 5 are perspective views of a receiving member of a suture clip in accordance with the present invention;

Figure 6 is a top plan view of the receiving member of Figures 4 and 5;

Figures 7 and 8 are perspective views of an insertion member of a suture clip in accordance with the present invention;

Figure 9 is a top plan view of the insertion member of Figures 7 and 8;

Figures 10 and 11 are perspective views of a suture clip in accordance with an embodiment of the invention;

Figures 12-14 are perspective views showing use of the suture clip of Figure 10 in securing a suture thread;

Figures 15-17 are partially cut away views corresponding to Figures 12-14;

Figure 18 is a sectional view along the line I-I of Figure 14; and

Figure 19 is a perspective view of a cartridge of suture clips in accordance with a further aspect of the invention. DETAILED DESCRIPTION

Figures 1 to 3 show a suturing needle 2 through the eye of which is passed a loop 4 of a thread of suture material, in this example a biodegradable monofilament material. The loop 4 in this example is formed by knotting at 6 and has a leading part 8 and a trailing part 10. The needle 2 is passed through tissue 12 being sutured. After passing through the tissue 12, the needle 2 is passed through the loop 4, pulling the leading part 8 through and beyond the trailing part 10 of the loop 4. This process may be repeated a number of times, for example to form a running lock suture, or a single suture may be formed as in the present example. The suture thread is held under tension and a suture clip 42 is applied adjacent to the point of engagement 16 of the leading and trailing parts 8, 10. The suture clip 42 grips the leading parts 8 with a good pullout strength, by a mechanism which will be described presently. The suture clip 42 has a peripheral surface 18 which is closest to -the surface -14 of the tissue 12 when the clip 42 is in use. The peripheral surface 18 engages or abuts either the trailing part 10 of the loop 4 or the surface 14 of the surrounding tissue 12. The peripheral surface 18 distributes pressure substantially evenly across the footprint of the clip 42 to reduce trauma to the tissue 12. Alternatively to being passed through tissue, it will be understood that the needle 2 could also be passed around tissue to be sutured, for example to close off a vessel.

As best shown in Figures 10 and 11, the suture clip 42 comprises a receiving member 20 and an insertion member 28. The clip 42 is manufactured from a biodegradable polymer material by a micromouiding technique. As manufactured, the clip 42 is integrally formed, with the insertion member 28 partly disposed in a first position within a passage 26 through the receiving member. The insertion member 28 is joined to the receiving member 20 by a thin web of material 44, which wU] be broken when the clip 42 is fastened.

Referring now to Figures 4 to 6, the receiving member 20 in has in this example a generally U-shaped profile in plan view (Figure 6), with a channel 30 between a first wall 22 and a second wall 24 of the receiving member 20. The leading part 8 of the loop 4 will be received in the channel 30 when the clip 42 is to be secured to the suture thread. The first wall 22 has a first opening 25, and the second wall 24 has a second opening 27. The openings 25, 27 define the passage 26 which extends through the receiving member 20 and which intersects the channel 30. The receiving member 20 has, in this example, a length of about 3.5 mm, and a width and depth each of about 2.5 mm.

Referring now to Figures 7 to 9, the receiving member 28 has in this example a generally U-shaped or C-shaped profile, with legs 32 connected to a body portion 38. Each leg 32 has a foot 34 and, between the foot 34 and leg 32, a barb portion 36. In this example, the barb 36 is formed at a slight acute angle relative to the foot 34. The body portion 38 has a curved surface 40 which faces into the receiving member 20.

Figures 12 to 17 illustrate stages in the process of locking the clip 42 to a leading part 8 of the loop 4. The two suture threads of the leading part 8 are initially located within the channel 30 of the receiving member 20, under suitable tension. Force is applied to the feet 34 of the insertion member 28 so as to drive the insertion member 28 from the first position through the passage 26, to the second position shown in Figures 14 and 17. As the insertion member 28 is driven inwards, the leading rounded surface 40 initially makes contact with the leading part 8 and then drives a portion of the leading part 8 of the suture threads out of the channel 30 and through the second opening 27 where the portion is retained under tension. The force applied to the insertion member 28 may be manually applied, but is preferably applied by a suitable applicator, notably an applicator which simultaneously holds on to the receiving member 20.

The biodegradable plastics material from which the suture clip 42 is manufactured is sufficiently deformable and resilient to allow the legs 32 of the insertion member to move slightly from their initial rest position. As the insertion member 28 is inserted into the receiving member 20, the legs 32 are pushed towards each other by the sides of the first opening 25. The first wall 22 has an internal shoulder 46 around the first opening 25. When the insertion member 28 has been fully inserted into the receiving member 20 (Figure 18), the barbs 36 on the insertion member snap back to their rest position where they engage with the shoulders 46, thereby resisting removal of the insertion member 28 through the first opening 25. The insertion member 28 and the displaced portions of suture thread may be entirely contained within the footprint of the receiving member 20.

The external footprint of the receiving member 20, and of the suture clip 42 when fastened, is substantially symmetrical about a plane through the channel 30. The suture threads 8 are held centrally in the channel 30 so that the suture clip 42 naturally locates evenly over the sutured tissue, thereby minimising turning forces so that the suture clip will sit as flat as possible at the wound site, and distribute pressure evenly across the footprint of the clip to reduce tissue trauma. The clip 42 holds the suture threads very securely, with good pullout strength. Measured pullout strengths for different diameter suture threads were as follows: 0.3 mm (11.1 N); 0.35 mm (25.6 N); 0.4 mm (27.3 N), which are comparable with published data for tied knots.

In a preferred embodiment, the clips 42 are applied by an applicator, which may be loaded with a cartridge 48 comprising a plurality of clips 42, as shown in Figure 19. The plurality of clips 42 may be formed in a single micromoulding operation, and may optionally be connected together by frangible webs of material, or they may be formed separately and loaded into a suitable cartridge housing, optionally with spring-biasing means to urge each clip in turn to a position in which it can be applied by the applicator.

Claims

1. A suture clip comprising a receiving member and an insertion member; the receiving member having a channel for receiving a suture thread, and a passage within which the insertion member may be adjusted by means of an externally-applied force between a first position in which a suture thread may be inserted into or removed from the passage, and a second position in which the insertion member will prevent removal of a suture thread from the receiving member; the insertion member and the receiving member being provided with interengagable features which when interengaged will resist adjustment of the insertion member from the second position.

2. A suture clip according to claim 1 , wherein when the insertion member is in the second position substantially no part of the insertion member projects outside the receiving member.

3. A suture clip according to claim 1 or claim 2, wherein the channel is open along its length so that a suture thread can be laid in the channel by lateral insertion.

4. A suture clip according to any preceding claim, which has a footprint that is substantially symmetrical about a plane of symmetry.

5. A suture clip according to any preceding claim, wherein the receiving member is substantially symmetrical about a plane through the channel.

6. A suture dip according to any preceding claim wherein the arrangement is such that, when a suture thread is located in the channel and the insertion member is in the first position, adjustment of the insertion member from the first position to the second position will move a portion of the thread out of the channel and into the passage where it will be retained by the insertion member.

7. A suture clip according to any preceding claim, wherein the entire clip is integrally formed from a single material.

8. A suture clip according to claim 7, which is formed as a one-piece moulding in which the insertion member is located in the first position, attached to the receiving member by a thin web of material.

9. A suture clip according to any preceding claim, wherein the insertion member is slidable in a straight line between the first and second positions.

10. A suture clip according to any preceding claim, wherein the insertion member is substantially symmetrical about a central plane.

11. A suture clip according to claim 10, wherein the insertion member is .generally U-shaped or C-shaped, with the free ends projecting outside the receiving member when the insertion member is in the first position.

12. A suture clip according to any preceding claim, having a footprint of length and breadth each in the range 2-5 mm.

13. A suture clip according to any of claims 1-11 , having a footprint of length and breadth each in the range 3-4 mm.

14. A suture clip according to any of claims 1-11 , having a footprint of dimensions about 2.5 x 3.5 mm.

15. A suture clip according to any preceding claim, which is formed from a biodegradable material.

16. A suture clip according to any preceding claim, wherein the interengagable features comprise at least one barb on one of the insertion member and the receiving member, and at least one notch or shoulder on the other.

17. A cartridge contain a plurality of suture clips as specified in any preceding claim and from which the clips may be serially dispensed.

18. A method of suturing comprising providing a closed loop of suture material with a leading part for attachment to a needle and a trailing part, passing the leading part through or around tissue to be sutured and then through the trailing part of the loop, tensioning the suture material so that the leading and trailing parts engage, and applying to the suture material a suture clip as specified in claim 1 to hold the suture material under tension.

19. A method according to claim 18, wherein the suture clip has a peripheral surface which is closest to a surface of the tissue when the clip is in use and which distributes pressure substantially evenly across the footprint of the clip to reduce tissue trauma.