SURGICAL CLIP

Abstract: A surgical clip is provided for clipping tissue, for example for clamping a bleeding blood vessel. The clip has at least three arms which are secured together at their proximal ends and have distal end portions which, in the rest state thereof, form a diverging, non-coplanar array. The clip has a sleeve which is movable from a position in which the arms adopt their rest state to a position in which the distal end portions of the arms are closer together to engage tissue.

Description: SURGICAL CLIP This invention relates to a surgical clip for use in endoscope clipping procedures. Clips of this type are known, and are employed, for example, in haemostasis (stopping bleeding) and marking medically significant sites (e.g. the sites of tumours) in the gastrointestinal tract. Such clips have been used for a considerable number of years with rigid endoscopes. However, they have significant shortcomings, and with the increased use of endoscopy in recent years, for example as the results of the development of flexible endoscopy, there is, and has been for some time, a need for improved clips. A widely used prior art clip is shown in Figure 1 of the accompanying drawings, in the configuration it has prior to use. As can be seen, this comprises a pair of arms 1 of resilient material which cross one another to form a general X-shape, the proximal ends of the arms received being in a sleeve 2 which is longitudinally slidable thereon. The proximal ends of the arms are connected, at a point which, in the view of Figure 1, is within the sleeve 2, to one end of a connector 3. The other end of the connector 3 can be connected by means of the opening 4 to a clip fixing device. The arms have proximal portions la which, at their maximum distance from one another, are slightly further apart than the internal diameter of the mounting 2, and distal portions lb which extend to a point where they are much further apart. The distal portions terminate in engaging portions lc adapted to engage body tissue. In use, the sleeve 2 is slid rightwardly, by an actuating device. The initial effect of this to compress the proximal arm portions la and thereby cause the distal arm portions lb to move even further apart. The arms are then positioned so that the engaging portions lc are located in the correct position in relation to the tissue which is to be clipped. The sleeve 2 is then slid further rightwardly, so that it engages the distal arm portions lb and forces them towards one another, thus causing the tissue to be engaged by the engaging portions lc . One major drawback with the clip just described is that in many situations it can only effect clipping if it is oriented in one particular way. To allow for this, the clip is applied using an actuator which allows the clip to be rotated about its longitudinal axis. However, not only does this complicate the clipping procedure, but it cannot always be employed effectively. For example, when trying to clip an artery in a bleeding ulcer the surgeon may not be able to tell which way the artery runs, and hence will not know which way to orientate the clip. An object of the present invention is to avoid this problem. Particular embodiments of the invention will now be described below which have additional advantages. According to the present invention there is provided a surgical clip comprising at least three arms which are secured together at their proximal ends and have distal end portions which, in the rest state thereof, form a diverging, non-coplanar array, and a sleeve movable from a first position in which the arms adopt their rest state to a second position in which the distal end portions of the arms are closer together to engage tissue which is to be clipped. The invention is further described below with reference to Figures 2a to 6c of the accompanying diagrammatic drawings, in which: Figure 2a and 2b are perspective and end views respectively of an embodiment of the invention; Figures 3, 4 and 5 show successive stages in the use of the embodiment of Figure 2; and Figures 6a to 6c show three types of surface pattern which may be provided at the tips of the . arms used in the clip of the invention. As shown in Figures 2a and 2b, a clip 10 according to the invention comprises three resilient arms 11 which are attached at their proximal ends to a common mounting 12 and which, in the illustrated rest position, diverge towards the proximal ends. As can be seen from Figure 2b, the diverging arm portions are non-coplanar and, as considered in an end projection, diverge approximately equiangularly, i.e. at about 120° to one another. It is to be understood, however, that equiangular divergence is not essential. It is further to be understood that there could be more than three arms, for example four arms. Each arm 11 has a tip portion 13 extending at an angle, for example at about 90°, to the adjoining portion of the arm. For example, each arm can be a resilient metal wire, and each tip portion 13 can be an integral end portion of the respective wire. If desired, the tip portion 13, or the whole of each arm, can be coated with a plastics material, for example by injection moulding, to reduce the risk of damage to the patient's tissue. Preferably, the tip portions are so oriented that when the diverging arm portions are brought together (see below) the tip portions extend at least approximately parallel to one another, so that any two adjacent tip portions can form a parallel sided, tissue engaging clamp. Alternatively or additionally, the arms can be made of slightly different lengths to one another, so that when they are brought together the tip portions of the arms do not prevent the arms coming close enough together to engage the tissue securely. Other possibilities for the tip portions are described below. Part way along its length, each diverging arm portion has a V-shaped section 14. The purpose of these sections is explained below. A sleeve 15 is slidably received on the arms . The bore of the sleeve has a widened section 16 intermediate its length. The operation of the clip 10 can best be understood by consideration of Figures 3 to 5, which show the use of the clip in clamping a bleeding blood vessel 20. The clip is introduced into the patient's body by means of an endoscope 21, for example a flexible endoscope, having a biopsy channel 22. The clip 10 is held in place with respect to the endoscope by a wire 23 running in a sheath 24, both of which extend along the biopsy channel 22. The clip 10 is releasably attached to the wire 23. In Figures 3 and 4 this is shown, by way of example, as being by the clip being provided with a hook 25 and the wire 23 being a double run of wire which extends from the proximal end of the endoscope down the biopsy channel, round the hook and back to the proximal end, the proximal ends of the wire being held by a wire clamp 26. The endoscope, with the clip mounted on the distal end thereof, as shown, is introduced into the patient's body until the clip is adjacent the location where the blood vessel is located. To clamp the blood vessel the clip is then moved towards the blood vessel until two of the arms- pass one side of the vessel and the third arm passes the other side. It will be appreciated that it is not necessary to rotate the clip above its longitudinal axis to achieve this. It will be achieved whatever the rotational orientation of the clip. The endoscope is then moved further longitudinally, i.e. towards the site where the clip is to be attached to the blood vessel, whilst a restraining rightward force is exerted on the wire clamp 26. Since the external size of the sleeve 15 is greater .than the internal size of the biopsy channel, the sleeve is thereby forced leftwardly with respect to the arms 11 until the V-shaped sections 14 of the arm engage in the widened section 16 of the sleeve bore. The situation is then as shown in Figure 4. Finally, the wire clamp 26 is released and the endoscope 21 withdrawn, leaving the clip 10 in place on the blood vessel, as shown in Figure 5. Various modifications may be made to the clip described above. For example, instead of merely using portions of the wire arms as the tip portions 12, additional members could be attached to the ends of the arms, and such additional members could carry, on those faces between which the tissue to be clipped, serrations or other patterns to improve the grip of the members on the tissue. Examples of some possible patterns are shown in Figures 6a to 6c. Furthermore, modifications may be made to the device by which the clip is installed. For example, the function of the components 21 to 24 as regards clip installation may be taken over by a wire-wound cable (i.e. a Bowden-type cable) which is located in the biopsy channel of an endoscope. This gives greater freedom as regards use of the device, though it also means that the elements of the installation device must be further reduced in size, compared to the "front-loading" method described with reference to Figures 3 to 5m which allows larger, and therefore stronger, clips to be used.

Claims: CLAIMS : 1. A surgical clip comprising at least three arms which are secured together at their proximal ends and have distal end portions which, in the rest state thereof, form a diverging, non-coplanar array, and a sleeve movable from a first position in which the arms adopt their rest state to a second position in which the distal end portions of the arms are closer together to engage tissue which is to be clipped. 2. A surgical clip according to claim 1, wherein there are precisely three arms . 3. A surgical clip according to claim 2, wherein the arms diverge approximately equiangularly from one another, as considered in an end projection. 4. A surgical clip according to any preceding claim, wherein each arm is in the form of a resilient metal wire. 5. A surgical clip according to any preceding claim, wherein each arm has a main portion and a tip portion extending at an angle to the main portion. 6. A surgical clip according to claim 5, wherein the tip portions are so orientated that when the arms are brought together the tip portions extend at least approximately parallel to one another. 7. A surgical clip according to claim 5 or 6, wherein the tip portion and main portion of each arm are integral with one another. 8. A surgical clip according to claim 5, 6 or 7, wherein the arms are of different length to one another. 9. A surgical clip according to claim 5 or 6 , wherein the tip portions are provided by additional members attached to the ends of the arms . 10. A surgical clip according to claim 9, wherein the said additional members have tissue gripping faces provided with a pattern adapted to increasing the grip thereof on the tissue to be clipped. 11. A surgical clip according to any preceding claim, wherein each arm has an outwardly extending portion adapted to be engaged by the sleeve when it moves from its first to its second position. 12. A surgical clip according to claim 11, wherein each said outwardly extending portion is a V-shaped portion. 13. A surgical clip according to claim 11 or 12, wherein the sleeve has a bore with a widened section intermediate its length, the widened portion being adapted to receive the outwardly extending portions of the clip. 14. A surgical clip according to any preceding claim, further comprising means for releasable attachment to means for exerting on the clip a force to cause the sleeve to move from its first position to its second position. 15. A combination of a surgical clip according to claim 14 and an endoscope on the distal end of which the clip is mounted. 16. A combination according to claim 15, wherein the force exerting means passes through a channel in the endoscope to the proximal end of the endoscope, and wherein the sleeve has a cross-section too large to permit it to pass through the said channel . 17. A method of engaging tissue to effect clipping thereof, comprising: providing a surgical clip comprising at least three arms which are secured together at their proximal ends and have distal end portion which, in the rest state thereof, form a diverging, non-coplanar array, and a sleeve movable from a first position in which the arms adopt their rest state to a second position in which the distal end portions of the arms are closer together to engage tissue which is to be clipped; and moving the sleeve from its first position to its second position. 18. A method according to claim 17, wherein the clip is initially mounted at the distal end of an endoscope, the endoscope, with the clip mounted thereon, is moved to the location of the said tissue, and the sleeve is then moved from its first position to its second position.

Inventors: GONG FENG, MILLS TIMOTHY NOEL, SWAIN PAUL, GONG, FENG, MILLS, TIMOTHY, NOEL, SWAIN, PAUL
Applicants: GONG FENG, MILLS TIMOTHY NOEL, SWAIN PAUL, UNIV LONDON, GONG, FENG, MILLS, TIMOTHY, NOEL, SWAIN, PAUL, UNIVERSITY COLLEGE LONDON
Application year: 1998
Main classification: A61B17
IPC codes: A61B17, A61B19