GB2055583A - Thread retriever - Google Patents

Abstract

The invention relates to apparatus for retrieving a thread particularly in a location where the thread is not readily accessible in surgical, medical and veterinary procedures (e.g. the thread of an intrauterine contraceptive device), comprising elongate anterior and proximal portions 20, 22 which may be detachably connected together, the anterior portion having along its length means, e.g. notches 26, by which in use the thread is caught and withdrawn. <IMAGE>

Description

SPECIFICATION I.U.D. thread retriever The invention relates to apparatus for retrieving threads in locations where they are not readily accessible with forceps in a variety of surgical, medical and veterinary procedures, and is particularly for retrieving a thread or threads of an intrauterine contraceptive device (I.U.D.) in a uterus.

One method of contraception that is commonly used is the intrauterine contraceptive device (I.U.D.).

Such devices are generally of a plastics material, for example polyethylene, which may optionally comprise at the exterior surface a metal, especially copper. A variety of different types of intrauterine contraceptive devices are available, but all are designed to be placed in the uterus of the woman in orderto prevent conception; they may, in general, be left there as long as contraception is desired. In all patients, the l.U.D. has, however, to be removed eventually: this may be because the woman wishes to become pregnant, or it may be because the device is to be replaced by a fresh l.U.D. as is recommended for certain l.U.D.'s after they have been in position for, for example, two years, or it may be medical or other reasons.

When correctly positioned within the uterus, the I.U.D. itself is not normally directly accessible and l.U.D.'s are therefore usually provided with a thread or threads in order to facilitate their removal from the uterus. When correctly positioned, such threads should extend from the I.U.D., through the cervix, into the vaginal cavity. The thread(s) may be grasped within the vaginal cavity, by means of forceps for example, and may be used to withdraw the l.U.D.

from the uterus without the patient having to undergo general anaesthetic.

It not infrequently happens, however, that the thread(s) cannot be found within the vaginal cavity.

This may be noticed by the woman herself during self-examination, or it may be noticed on examination by a medical worker during a periodic check or during examination for pregnancy or other reasons.

It is then necessary to ascertain the reason for the absence of the thread(s) from the vaginal cavity as soon as possible, especially as it may be that the l.U.D. has been expelled from the woman unnoticed, with the consequent risk of unwanted pregnancy, and/or that the l.U.D. has become translocated, that is to say that it has penertated through the wall of the uterus, which can cause serious complications. In most cases, however, the l.U.D. is still located within the uterus and the thread(s) have, for some reason, become drawn up into the endocervical canal. This may occur for a variety of reasons, including inversion of the l.U.D. within the uterus, enlargement of the uterus, and the thread(s) resuming the "folded" position they had in the package of the l.U.D.

In general, the initial procedure on noticing the absence of the thread(s) from the vaginal cavity is exploration of the endocervical canal with forceps to ascertain whether the threads can be found there. If the threads still cannot be found, as happens in many cases, there is the problem of ascertaining whether the l.U.D. is still located within the uterus, and, if so, of withdrawing the thread(s) from the uterus in orderto remove the I.U.D. Even if it is ascertained that the l.U.D. is still correctly located and it is desired to leave it in position for the time being, it is generally not considered satisfactory to do so while leaving the thread(s) drawn up into the uterus.

Ultrasound examination, for example, can be used to determine whether the l.U.D. is still in position, but such examination requires expensive equipment and cannot normally be carried out in clinics. In any case, it does not solve the problem of retrieving the threads. Sometimes, exploration further into the uterus can be carried out using forceps or other instruments, but this can entail risk of perforating the wall of the uterus and it requires the use of anaesthetic and usually admission to hospital. Moreover, especially in nulliparous women, it is not always readily possible to pass such instruments through the cervix.

None of these methods is entirely satisfactory in ascertaining whether the l.U.D. is still correctly located and in achieving withdrawal of the thread(s) into the vaginal cavity where they can readily be grasped by forceps. If the thread(s) cannot be retrieved in any of these ways, it becomes necessary to remove the I.U.D. under general anaesthetic in hospital.

Experiments have been carried out using a "Mi Mark Helix" (Trade Mark: U.S. Patent Specification Nos. 3 945372 and 4054 127) for retrieving the thread(s) of l.U.D.'s from the uterus. The "Mi-Mark Helix" is an instrument designed for obtaining endometrail tissue samples from the wall of the uterus and has a helically-shaped flexible end section for scraping the uterus wall and which is curved in order to conform to some degree to the shape of the uterus wall. However, this instrument is not always successfully able to retrieve thread(s) and forceps may still be required, which is not favourable for nulliparous women.

According to the invention there is provided apparatus for retrieving a thread particularly in a location where the thread is not readily accessible in surgical, medical and veterinary procedures, comprising elongate anterior and proximal portions connected together, the anterior portion having along its length a surface element by which in use the thread is caught and for drawing the thread towards the proximal portion.

The apparatus according to the invention provides a simple and safe means of "sounding" the uterus to determine whether an l.U.D. is present and of retrieving withdrawn thread(s).

The surface element may be a notch. The open end of the notch may be nearer the proximal portion than is the closed end of the notch. There may be a plurality of notches along the length of the anterior portion. This provides a construction which provides several opportunities to catch or retrieve a thread.

The anterior portion may be substantially rectangular and flat. This provides a construction which is readily made, particularly where the apparatus is moulded from plastics material.

The anterior portion may alternatively be oval in transverse cross-section, or of hexagonal transverse cross-section.

The anterior portion may be resilient. This construction has the advantage that the anterior portion can conform to the shape of the wall of the uterus.

Also, the anterior portion may comprise a material which has an elastic "memory", so that it can be bent to a desired shape prior to insertion in the uterus. The sides of the or each notch may merge into a rounded blind end, which provides a smooth part of which the thread(s) bear.

In orderto obviate the danger of perforation of the uterine wall, the free end of the anterior portion may be bulbous.

The apparatus can be sterilised by any suitable known method, for example, sterilisation in an autoclave, byy-rays, sterilisation by means of ethylene oxide, or "cold chemical" sterilisation; when the apparatus is made of plastics material that material should be one that is not adversely affected by at least one suitable sterilisation method. Such an instrument may be used a few times, being sterilised between each use, and then be discarded. The apparatus may be made of metal such as stainless steel, or metal coated with plastics. The proximal portion is preferably relatively rigid compared to the anterior portion. This provides a positive "feel" when the anterior portion is within the uterus, the proximal portion being within the vaginal cavity.

Plastics materials of which the apparatus or at least the anterior portion thereof may be made of any suitable inert plastics material, for example homopolypropylene, high-density polyethylene or nylon. The anterior portion may be of triform (y shaped) or crusiform transverse cross-section. In this case, the anterior portion includes three or four or more "blades" joined together along their inner edges and carrying notches on their outer edges.

The anterior portion is flexible.

Also, the anterior portion may have a zig-zag configuration, with the notches being at the position where the direction changes from a zig to a zag. It will be understood that the notches are preferably of such a size and so shaped that they can readily catch and engage a thread orthreads and that, once engaged in the notch, the thread(s) cannot readily slip or fall out. The opening of each notch, as measured longitudinally along the edge or side of the anterior portion, is advantageously narrower than the width of the base of the notch. The opening may be from 1 to 5 mm, preferably from 2 to 4 mm, especially about 3 mm, wide. The edges of the or each notch are advantageously rounded. This assists in preventing the apparatus from catching on the inter nal walls of any cavities in which it is being used, and can also assist in engaging threads.

Apparatus embodying the invention is hereinafter described, by way of example, with reference to the accompanying drawings, in which:~ Fig. 1 is an elevation view of one form of l.U.D.

thread retriever according to the invention; and Fig. 2 is a cross-sectional view on the line Il-Il of Fig. 1.

Referring to the drawings, the I.U.D. thread retriever 1 shown in Figures 1 and 2 comprises an elongate flexible anterior portion 20 and, integral therewith, a proximal portion in the form of a rodshaped substantially rigid handle 22 of hexagonal transverse cross-section. The anterior portion 20 is substantially rectangular and flat (see Fig. 2) except that its free end 24 remote from the handle 22 is bulbous. There is a surface element in the form of a plurality of thread-engaging notches 26 which are provided in each edge of the anterior portion 20, the notches in one edge being staggered with respect to those in the other edge, and the notches being so arranged that the open end of each notch 26 is nearerto the handle 22 than is its closed end. The edges 28 and 30 of each notch 26 are slightly rounded'.The sides of each notch 26 merge into a rounded blind end of the notch.

The retriever 1 may suitably be of homopolypropylene and may have an overall length of about 25 cms. The anterior portion 20 may suitably have a length of about 9 cm. width of about 4 mm, and a maximum thickness of about 2 mm. The bulbous end 24 may suitably be about 4 mm wide and about 3 mm thick. The notches 26 along each edge of the anterior portion 20 may suitably be spaced about 10 mm apart and may be staggered on opposite edges by about 5 mm.

The retriever 1 may be used in examining a woman patient whose intrauterine contraceptive device thread(s) are "lost" in order, first, to ascertain whetherthe I.U.D. is still presentwithinthe uterus and, secondly, to retrieve the lost thread(s). The retriever is inserted, with its bulbous end 24 first, through the vagina of the patient and then through the cervical canal and into the endocervical cavity of the uterus, so that at least part of the handle 22 still projects from the vagina. The retriever is then moved about, with the anterior portion 20 inside the uterus, in orderto "sound" the uterus and detect the presence of an l.U.D. It may then be moved around further and rotated in orderto engage the thread or threads of the I.U.D. in the notches 26.It is then withdrawn, possibly with continued rotation, in order to retrieve the thread or threads from the uterus so that the thread(s) are engaged at the os cervix. The l.U.D. may then be removed, replaced or left in position as desired.

It will be understood that the retriever may have any desired shape, for example the proximal end may be rounded or flat, and the anterior portion may be helical, with notches 26. Also, the free end of the anterior portion may simply be rounded as opposed to bulbous. Further, the anterior and proximal portions may be actually separate, the separate portions being assembled to form the complete apparatus, In this embodiment, the two portions have respective releasably securable connectors such as a spigot and socket which can be connected together. The spigot and socket may be a push4it or may be screw-threaded.

Although not shown, the retriever may carry a series of gradations comprising a distance scale on its external surface. The depth of the uterine cavity can then readily be measured when the extractor is inserted.

The apparatus above described and shown in the drawings constitutes a simple, safe and effective means of "sounding" the uterus to detect the presence of an intrauterine contraceptive device and of retrieving "lost" thread(s), which can be carried outin, for example, a clinic, hospital out-patients department, or a doctor's surgery without the need for general anaesthesia and hospitilisation and without having to refer the patient to a gynaecological specialist, all of which latter conditions are expensive in terms of time and money.

Claims (11)

1. Apparatus for retrieving a thread particularly in a location where the thread is not readily accessible in surgical, medical and vetinerary procedures, comprising elongate anterior and proximal portions connected together, the anterior portion having along its length a surface element by which in use the thread is caught and for drawing the thread towards the proximal portion.

2. Apparatus according to Claim 1, the surface element comprising a notch, the open end of the notch being nearerthe proximal portion than is the closed end of the notch.

3. Apparatus according to Claim 2, in which there is a plurality of notches along the length of the anterior portion.

4. Apparatus according to Claim 2 or Claim 3, in which the anterior portion is substantially rectangular and is flat.

5. Apparatus according to Claim 2 or Claim 3, in which the anterior portion is of oval transverse cross-section.

6. Apparatus according to any preceding Claim, in which the anterior portion is resilient.

7. Apparatus according to any of Claims 1 to 5, in which the anterior portion comprises a material which has an elastic "memory".

8. Apparatus according to any preceding Claim, in which the free end of the anterior portions is bulbous.

9. Apparatus according to any of Claims 2 to 8, in which the sides of the or each notch merge in a rounded blind end of the notch or notches.

10. Apparatus according to any preceding Claim, made in one piecewherebythe anterior and proximal portions are integral.

11. Apparatus for retrieving a thread in a location where the thread is readily accessible in surgical, medical and veterinary procedures, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.