IES60980B2 - Multi-sample forceps - Google Patents

Description

MULTISAMPLE FORCEPS The present invention relates to improvements in forceps systems for use in endoscopes Endoscopy is a special medical examination of the interior of the body, usually through a natural body opening, by the insertion of a tube device. Recent advances in fibre optics and in ultraminiaturized photography have greatly improved endoscopic examination of the stomach 25 and gastro-intestinal tract, the bowels, rectum, and other internal organs. The great advantage of these techniques is that surgery is not required, or in some cases, only a minor incision is required. In conjunction with endoscopic examination, biopsy may be employed to remove tiny samples of tissue or body fluids from internal organs via a 30 tube device. Typically, an endoscope may comprise a bundle of fibre optic cables disposed around a central passageway through which other surgical devices including, for example, cable-operated biopsy forceps, may be passed. When using a cable-operated forceps of small dimensions for endoscopic biopsy, a separate insertion and removal is required for 35 each test. Such a procedure can be very tedious when a number of tests S 6 09 80 - 2 are in question, since endoscopic tubes may extend up to 7 feet within the body., The usual maximum diameter for the central core passageway is typically 32 mm., but it may be of lesser size.

It is an object of the invention to provide an improved forceps system for use in an endoscope which will enable the retrieval of multiple samples without necessitating withdrawal of the forceps from the endoscope for release of each individual sample.

According to the invention, there is provided a forceps system for use in an endoscope, comprising a tissue-separating portion and a duct having a first end region located substantially at said tissue-separating portion and a second end region which may be located remotely from said tissue-separating portion, said duct serving for transfer of tissue portions separated by said tissue-separating portion and released by said portion for entry into said duct, from said first end region of the duct to said second end region, for retrieval in use of the system.

In a first variant of the invention, said duct may be defined by a passage of an endoscope. Suitably, the system comprises means for effecting a tissue-separating operation of said tissue-separating portion, and said operation-effecting means may comprise at least one member extending through said passage of the endoscope defining said duct. Alternatively, said operation-effecting means may comprise at least one member extending through another passage of the endoscope.

In a favoured embodiment of the forceps system of the invention, said duct is defined by a tube insertable through a passage or an endoscope. In an especially favoured arrangement, said tube is accommodated within a sleeve, said sleeve and tube being together insertable through a passage of an endoscope. Preferably, said sleeve is of generally circular cross-section and said tube accommodated with said sleeve has a cross-section defining at least one flow passage between said tube and sleeve. In a particularly favoured embodiment of this aspect of the invention, said tube is also of generally circular cross-section having at least one flat portion to define said at least one flow passage.

In the sleeved variant of the invention, said first end region of said tube may comprise a plurality of jaws defining said tissue-separating portion and a tissue-separating operation is executed by effecting relative axial displacement of said tube and said sleeve. In general, said tissue-separating portion suitably comprises said first end region 10 of said tube, and said first end region of said tube may further comprise at least one cutting edge. In a variety of arrangements according to the invention, said first end region of said tube may comprise a plurality of jaws, as particularly favoured for the sleeved duct construction already described.

In an alternative construction, said tissue-separating portion may comprise a cutter located at said first end region of said tube. Means are then suitably also provided for effecting a tissue-separating operation of said tissue-separating portion, said operation-effecting 20 means comprising, for example, at least one member extending through said duct to said cutter.

Said transfer of tissue portions separated by said tissue-separating portion through said duct may be effected by vacuum means of the system 25 of the invention, in a first embodiment of this feature of the invention. Alternatively, in a favoured arrangement, the system of the invention may comprise pressure means for effecting said transfer of tissue portions separated by said tissue-separating portion through said duct. Said pressure means may comprise means for providing a supply of water under pressure at said first end region of the duct for establishing a flow of water through said duct towards said second end region to entrain in said flow tissue portions separated by said tissue-separating portion and thereby effect said transfer of said tissue portions. _ 4 The invention extends not only to a forceps system substantially as described herein with reference to and as shown in any one or more of the accompanying drawings, but also to an endoscopic system comprising any of the features of the forceps system as previously described, as well as an endoscope provided with a forceps system incorporating the features of the invention.

Advantages of the invention are the ability to take samples within the human body for return to the exterior without necessarily withdrawing the biopsy device. The samples are conveyed along the duct communicating between the separating or jaw region of the device and the exterior, either by vacuum or by pressurised water flowing from the inner end of the device outwards. In either case, the same principle applies - namely the samples are entrained in an outward flow for retrieval at the external end of the duct of the system.

A variety of embodiments of the present invention will now be described in further detail with reference to the accompanying drawings, in which, Figure 1 is a longitudinal cross-section,, to a greatly enlarged scale, of the end of a suction biopsy tube device in accordance with the present invention, Figure 2 shows an alternative biting tip for use in the system of the invention, Figure 3 shows one of a diversity of sharpened wire loops usable as cutting devices within the system of the invention, Figure 4 is a representation of a rotary cutter for use in a system according to the invention, Figure 5 is a representation in cross-sectional view of a dragging tip type cutter for use in the system of the invention, Figure 6 shows a configuration of the invention in which transfer of samples for collection takes place in the outward direction from the cutting tip under the action of a water flow, water being supplied to the inner or cutting end of the device by means of a separate duct or 5 passage, Figure 7 is a representation of a dragging cutter for use in a two-channel system of the kind shown in Figure 5, Figure 8 is a cross-sectional view of a sleeved duct construction of the invention, in which passages for inward flow of water are defined between an outer sleeve and flattened portions of an internal tube, and Figure 9 is a pictorial representation of the system of Figure 8, 15 showing a pair of biting jaws integrally formed on the inner or tissue-engaging end of the inner tubular member of the sleeved system.

Figure 1 shows the forward portion of a metal fitting 1 for attachment to the end of a biopsy tube device. A tapered, sharpened leading edge 20 2 is formed at the end of the fitting, which defines an opening 3 communicating with a passageway 4, which in turn communicates with the interior of the biopsy tube. Inwardly-projecting barbs 5 are provided adjacent to the opening 3S which constrict the passageway 4 and are adapted to prevent fall-back of any retrieved sample once the leading 25 edge 2 is withdrawn from the surface of an internal body organ.

In use of the invention, the end of the device 1 is applied against the internal tissue from which the biopsy is to be taken. The cutting edge may merely rest against the tissue at the biopsy site, or alternatively, a degree of positive forward pressure may be applied to ensure that the leading edge 2 cuts into the tissue at the sampling site.

The tube extending through the endoscope, at the forward end of which fitting 1 is mounted, and which extends outwardly from the endoscope at its outer end to communicate with the external environment and associated apparatus, is suitably filled with water, for transmitting suction pulses to the leading end cutter 1 and for conveying separated biopsy samples back to the external end of the system for retrieval and examination. A pressure pulse at the external end of the system transmits a suction pulse to the cutter while it is held against tissue. A portion of tissue is thus separated and is drawn back along the water-filled tube for collection at the outer end. If the sudden pull applied by a vacuum pulse is insufficient to separate an appropriate amount of tissue, a physical movement of the cutter away from the tissue may also be carried out simultaneously with the pulse. Thus the pulse alone, or pulse and pull combined, effects the desired separation of tissue. Once the sample passes into the tube, the barbs 5 prevent it from being lost from the cutter at the cutting end, by virtue of a non-return action. Continued suction draws the sample back to the outer end for retrieval. A succession of samples may be withdrawn through a single tube, each being detached by the same cutter, but individually retrieved and identified at the outer end. In this way, a number of biopsies may be carried out for a single insertion of the biopsy device, as compared with a mechanical forceps-type biopsy device, where repeated withdrawals of the forceps are required to individually retrieve each sample.

The arrangement shown in Figure 1 represents one exemplification of a suction tip, in which samples are drawn into the duct through a small diameter opening at the leading end of the duct and cut from a larger body of tissue, as the sample expands to fill the chamber defined within the mouth of the duct to the rear of the cutting edge 2, this chamber having a larger diametral dimension than the cutting edge opening 3.

Figure 2 shows an alternative cutting arrangement, comprising a biting tip 11 received at the end of a duct 12 for communicating with the environment externally of the endoscope. Biting tip body portion 13 is tightly engaged in the end opening of duct 12, the apparent clearances shown between these components in Figure 2 being for clarity of representation only„ Cutter 14 is operated mechanically from the external end of the forceps system by a wire or rod 15 passing through duct 12 from an exterior operating or manipulation location. Thus, the sample is cut mechanically, and suction is relied upon only as a 5 means of retrieving the sample rather than also itself effecting the cutting action.

Figure 3 is a representation of a cutting arrangement in which sample separation is achieved using a sharpened wire loop 21 or like member, 10 defined at the internal or leading end of an activating member 25 extending through duct 22. As shown, activating member 25 comprises a dual wire structure. A diversity of cutter arrangements operating on the same general principle as that shown in Figure 3 may be provided. Alternative arrangements include open loop cutters, helical cutters, and hook-shaped cutters, while single- or double-wire activating arrangements may also be deployed, as appropriate.

Figure 4 shows a cutter 31 having a tip 33 using a rotary action to separate samples from the tissue body. Again, the rotary cutter 31 is 20 defined at the internal end of an activating member 35 in the form of a flexible rod or cable or wire extending axially through the duct 32 of the system of the invention, duct 32 itself also being flexible for insertion and feeding through an endoscope.

Figure 5 shows an arrangement in which the cutting action is provided by a so-called dragging tip 411 in which a shaped aperture 46 provided with a cutting edge 44 is defined at the internal or leading end of the duct 42 defined in this instance by a tube extending axially through the endoscope to the interior of the patient. In use of this embodiment, samples are separated by the dragging tip and withdrawn through the tube under vacuum. The cutter arrangement shown in this Figure may be a separate component affixed to the end of the duct or alternatively the cutter may be formed integrally at the inner or functional end of the duct to be located within the patient, to thereby comprise part of the duct. A similar option applies as appropriate to the various other cutting configurations and arrangements described herein.

A disadvantage of the foregoing structures is that sample displacement along the tube or duct by means of vacuum may in certain instances be insufficiently effective to ensure reliable sample retrieval at the outer or external end of system, for a variety of reasons, including difficulties in establishing flow through a relatively small bore tube and also partial obstruction of the tube caused by the presence of an operating wire or other like member (viz. cable, rod etc.) in the case of rotary or other like cutters. Accordingly, in an alternative construction, by using a double lumen tube, withdrawal of samples may be provided for in alternative manner by virtue of directing a continuous flow of water inwards through one lumen and the samples are then entrained in a water flow exiting through a second lumen for external retrieval. An unbroken water column may thus be defined within the exit lumen for carrying samples back to a specimen or collecting jar at the exit end of the system.

As shown in Figure 6, an arrangement of this kind provides a cutting tip 51 in which separation of a sample takes place by a needle type cutter 54 which penetrates the surface on forward movement of the device and retains a sample when withdrawn. Water flow takes place inwardly through a first lumen 57 or tube of the duct structure 52 and samples then exit entrained in the outward water flow through the exit lumen 58 of duct 52 which communicates with the cutter 51.

Figure 7 shows a dragging tip 61 type structure incorporating the dual flow arrangement of Figure 6. The inflow lumen is again identified by reference 57 and the exit lumen by reference 58.

Figure 8 shows an especially favoured construction of sleeved tube, in which an inner tube 71 defines the duct through which sample retrieval takes place and this inner tube 71 is axially sleeved within a substantially concentric outer tube or sleeve member 72. In order to define a region for inward flow of water, side portions 73 of the inner or sleeved tube or duct 71 are flattened, to define passages 74 between the outer surface of the tube 71 and the inner surface of the sleeve 12. In this manner water flow is directed inwardly through these arcuate or sectoral cross-sectional regions 74 and the water flows back through the inner duct or tube 71 and entrains samples. An arrangement of this kind may be associated with any of the cutting features already described.

However, in a particularly favoured arrangement, shown in pictorial representation in Figure 9, the inner end 81 of the inner sleeve 71 defines a jaw type structure, and a cutting action is effected by rearward axial displacement of the inner tube 71 relative to the sleeve 72 so that the outwardlv-biassed jaws 82, which occupy a normallv-open disposition, are thereby forced shut to grip and separate a portion of tissue. The apertured nature of the jaw region of the device, wherein apertures 83 define a termination of the axial slit 84 by means of which the jaws 82 are defined on each side of the structure, allows water flow into inner tube or duct 71 to take place in any condition of the jaws 82, whether open or closed, and thereby entrainment of samples for return to the collection end of the forceps system is achieved.

As each sample commences its journey to the exit end of the inner tube 71, the jaws may be released by relative axial displacement of the inner tube 71 to extend it forwards relative to the outer sleeve 72, and thereby release the jaws preparatory to retrieval of a further sample. Further details of a forceps system of this kind are described in a co-pending application of the present Applicant.

Preferably, the tube and sleeve are formed from a plastics material, such as a polycarbonate plastics material. Thus a substantiallv rigid structure is provided over a short length of the arrangement, but in aggregate, when embodied in for example a two metre long structure for Λ use in an endoscope, the device is sufficiently flexible to pass . through the endoscope. - 10 In further variants of the invention, the duct may in fact be defined by a passage of the endoscope proper, with the tissue separating means or cutter being located at the tip or functioning end of the endoscope. Two passages of the endoscope may be employed where water flow is used to entrain and carry samples to the outer end. Where physical activation of the cutter is required, the activating means may be carried through the retrieval passage or through another passage of the endoscope.

Where the system employs a separate tubular structure, passed through the endoscope at the time of use, the forceps and sample retrieval aspects of the invention may preferably be embodied in a disposable plastics structure, such as is further described in said copending application.

In all embodiments of the system of the invention however, the primary objective of the invention is achieved, namely to provide for sample retrieval externally of an endoscope without necessarily requiring withdrawal of the forceps after each cutting or tissue-engaging action.

Claims (5)

1. A forceps system for use in an endoscope, comprising a tissue-separating portion and a duct having a first end region located 5 substantially at said tissue-separating portion and a second end region which may be located remotely from said tissue-separating portion, said duct serving for transfer of tissue portions separated by said tissue-separating portion and released by said portion for entry into said duct, from said first end region of the duct to said second end 10 region, for retrieval in use of the system.

2. A forceps system according to Claim 1, wherein said duct is defined by a tube accommodated within a sleeve, said sleeve and tube being together insertable through a passage of an endoscope.

3. A forceps system according to Claim 1 or Claim 2, wherein said first end region of said duct comprises at least one cutting edge

4. A forceps system according to any of Claims 1 to 3, comprising 20 pressure means for effecting said transfer of tissue portions separated by said tissue-separating portion through said duct, wherein said pressure means comprises means for providing a supply of water under pressure at said first end region of the duct for establishing a flow of water through said duct towards said second end region to entrain in 25 said flow tissue portions separated by said tissue-separating portion and thereby effect said transfer of said tissue portions.

5. A forceps system substantially as described herein with reference to and as shown in any one or more of the accompanying 30 drawings.