This invention relates to a device for use in securing a thread. It is particularly intended for use in securing threads in surgery, and more particularly in surgery carried out using an endoscope, notably a flexible endoscope.

It has hitherto proved difficult to secure threads by knotting during flexible endoscopy. In effect, the surgeon is operating down a single longitudinally extending channel, and in endeavouring to tie a knot the surgeon encounters the problem that an effective knot generally requires the application of force along a direction transverse to the channel of the endoscope. The present invention aims to provide a solution to that problem.

According to the present invention there is provided a device for use in securing a thread, which comprises a tube provided with means defined at one end thereof for receiving therein a sleeve having a cavity in which a plug is insertable.

An embodiment of the invention is shown diagra matically in the accompanying drawings, which is a longitudinal section. It should be emphasised that the drawing is not to scale.

The device comprises a tube 1, which is preferably a flexible tube. At the distal end, i.e. the end which is to be inserted into the patient, an overtube 2 is fixedly secured to the tube 1 to define a recess 3. Extending along the outside of the tube 1, and over the end of the overtube 2, is a U-shaped stirrup 4. The stirrup may be made, for example, of a stainless steel wire. The stirrup is longitudinally slidable with respect to the tube 1, and the arms of the stirrup pass through respective guide passages 11. To enable sliding to be effected the proximal end of the stirrup is secured to a slide member 5

which can be grasped and moved by the user. In addition to the guide passageway 11, other means (not shown) are provided along the length of the outside of the tube, within which the stirrup is slidable, so as to prevent the stirrup slipping off the tube. Near its distal end, the tube 1 is provided with a pair of apertures 6 each of which has a diameter substantially greater than the diameter of the surgical thread with which the device is to be used. One of the apertures is visible in the drawing. The other is diametrically opposite to it. The purpose of the apertures 6 will become apparent from the description below of the use of the device.

The recess 3 serves to receive an elongate sleeve 7. The sleeve defines within it a cavity 8. The cavity 8 is open at one end to the end of the tube 1, and, although not shown, at that end the cavity is preferably chamfered. The other end of the cavity 8 communicates with the other end of the sleeve 7 by a passage 9. The stirrup 4 is offset with respect to the longitudinal axis of the tube 2, with which the passage 9 is aligned, so that when the stirrup is moved leftwards with respect to the tube it does not foul the end of the passage 9. The passage is smaller in diameter than the cavity 8, but large enough to permit the surgical thread to pass therethrough. A plug 10 is located in the cavity 8, the plug being of a size such that it can slide down the interior of the tube 1. The sleeve 7 is removable from the recess 3, and the plug 10 is removable from the cavity 8, and at the start of the procedure in which the device is used, the sleeve 7 and plug 10 are separate from one another and from the remainder of the device.

Prior to the thread-securing procedure in which the device of the present invention is used, the surgeon has carried out a surgical procedure in which a thread has been passed through the tissue of the patient, and the ends of the thread now need to be secured. It is assumed for

present purposes that the ends of the thread are outside the patient, and if surgery has been carried out using an endoscope then the ends of the thread will generally emerge through the mouth or anus. With the stirrup 4 in the position shown in the drawings, a sleeve 7 is inserted in the recess 3. At this point there is no plug in the cavity 8. The stirrup 4 is then moved leftwards, as viewed in the drawing, so that the sleeve is held in place in the recess by the stirrup. The ends of the thread are then introduced into the passage 9 from the distal end, and passed through the cavity 8 into the end of the tube 1, and each then exits the tube through a respective aperture 6. Instead of a pair of apertures it would alternatively be possible to use a single aperture, in which case both thread ends would pass through it. The whole device is then inserted into the patient until the distal end thereof is located adjacent the point at which the thread passes through the patient\'s tissue. During this insertion process the ends of the thread continue to be held outside the patient, so that, in effect, the end of the device slides down the thread. Preferably, the device is sufficiently small as to enable it to pass down the operating channel of flexible endoscope, for example the endoscope which has been used in carrying out the surgery described above.

When the end of the device is at the desired location, the plug 10 is introduced into the proximal end of the tube 1, and is pushed down the tube and into the cavity 8 by a flexible pusher rod (not shown) . Entry of the plug into the cavity is assisted if the cavity is being chamfered, as mentioned above. As the plug enters the cavity 8 it traps the thread against the internal wall of the plug, and friction between the sleeve 7, the plug 10 and the thread holds these elements together. If desired, the cavity 8 can taper as viewed from left to right.

The stirrup 4 s then moved to its extended position shown in the drawing, and the tube 1, with the

overtube 2 and stirrup 4, is removed from the patient. The sleeve 7 and plug 10 remain attached to the thread, and thus leave the recess 3 when the removal step just described takes place. During removal, the ends of the thread slide back through the aperture 6. The end portions of the thread can be severed on the side of the sleeve/plug combination remote from the tissue, by a severing operation.

After the procedure just described, the sleeve/plug combination remains in the patient, holding the ends of the thread to prevent their withdrawal through the tissue in which the thread has been inserted. If it were desired that the sleeve/plug combination should no longer be present after the need for it had passed, the sleeve and plug could be formed of a material was which slowly soluble. Otherwise, the plug and sleeve may be made, for example, of a surgically acceptable, inert plastics material.