WO1991008707A1

WO1991008707A1 - Biopsy instrument

Info

Publication number: WO1991008707A1
Application number: PCT/GB1990/001943
Authority: WO
Inventors: Joseph Lennox Peters; James William Kerr; Richard Anthony Harrison
Original assignee: Clinical Product Development Limited
Priority date: 1989-12-14
Filing date: 1990-12-13
Publication date: 1991-06-27
Also published as: CA2071212A1; EP0504276A1; AU6967491A; GB8928302D0; JPH05504697A

Abstract

A biopsy needle for percutaneous and direct human tissue biopsy procedures comprises a cannula (1) and a stylet (2) respectively attached to sliders (8, 9) guided for movement in a barrel (7) of a handle (5) which has a pistol grip (6). The sliders have actuating flanges (10, 11) projecting from opposite sides of the barrel for advancing them in turn with the thumb of the hand holding the instrument.

Description

BIOPSY INSTRUMENTS

This invention relates to biopsy instruments, and more especially is concerned with. biopsy instruments of a kind comprising parts which must be manually advanced and retracted relative to each other in performing a biopsy procedure with the instrument to take a specimen from a tissue mass.

A biopsy needle of the kind described above is disclosed in US-A-3477423, and this known instrument is that in most common use today for percutaneous and direct human tissue, e.g. breast biopsy procedures. It has an elongated tubular part or cannula with a sharp cutting edge at its distal end and fixed at its opposite, proximal end to a plastics hub which is of generally rectangular configuration and has a pair of opposed laterally projecting wings or flanges to assist in manually holding and manipulating the hub in use of the instrument. An inner stylet or obturator is received and is longitudinally slidable in the cannula. The stylet protrudes from both ends of the cannula and the forward or leading end of the stylet is shaped as a sharply pointed tip whereas the rear end of the stylet is fixed to a plastics slider. The slider includes an integral , forwardly extending tongue which cooperates with the cannula hub to prevent relative rotation of

SUBSTITUTE SHEET the cannula and stylet. The tongue is provided with a stop which by engagement with opposed abutments on the cannula hub limits the forward and rearward movement of the stylet between two predetermined end positions. Adjacent the tip the stylet has a notch which is located entirely within the cannula when the cannula is in the rear end position, and which is exposed when the stylet is moved to its forward end position.

To carry out a tissue biopsy procedure, the stylet is fully retracted to the rear end position and the tip of the needle is introduced into the body of the patient to a position near the tissue mass from which the specimen is to be taken. Holding the cannula hub in one hand and the slider in the other hand, the slider is then pushed forwards while the hub and cannula are held stationary, thereby causing the stylet to be advanced to its forward end position and the tip of the stylet to enter the tissue mass. The stylet notch becomes filled with the tissue and then, while holding the slider still, the hub must be pushed forwardly so that the cutting edge of the cannula severs the tissue filling the stylet notch and the stylet once again occupies its rear end position. To remove the specimen thus cut and captured within the cannula, the needle has to be withdrawn while the relative positions of the cannula and stylet are maintained.

The known biopsy needle is awkward to operate and, except in the hands of a surgeon with considerable dexterity, must be held in both hands, which is a great inconvenience since it is often desirable for one hand to be placed on the patient to assist in guiding the needle tip to the required location from which the specimen is to be taken.

The present invention aims to avoid the

SUBSTITUTESHEET drawback of the prior art biopsy needle and in accordance with the invention there is provided a biopsy instrument comprising first and second slide members fixed to respective parts to be advanced and retracted relative to each other in the performance of a biopsy procedure, and a handle mounting each of the slide members and guiding said members for longitudinal movement.

The instrument of the invention has the advantage that the handle remains in fixed position while the slide members are advanced in turn to cut and capture a tissue specimen. The handle is conveniently shaped as a pistol grip to be held in the fingers and palm of one hand while the thumb of the same hand can advance the slide members. The slide members can be arranged to project laterally from the handle, either from the same side or preferably from opposite sides of the handle for engagement by the thumb of the hand holding the instrument. Means may be provided to ensure the slide members are advanced in the correct order, e.g. by locking one slide member to the handle until the other slide member has been fully advanced relative to the handle.

A better understanding of the invention will be had from the following detailed description which is given with reference to the accompanying drawings, in which:

Figure 1 is a side elevation of a biopsy needle constructed in accordance with the invention;

Figure 2 is a view similar to Figure 1 , but shown partly in section;

Figure 3 is a horizontal sectional view through the biopsy needle; and

Figures 4 and 5 are views corresponding to

SUBSTITUTESHEET Figure 3 and illustrating the parts at successive stages of a biopsy procedure.

The biopsy needle shown in the drawings is of the same basic kind as the prior art biopsy needle described hereinabove. It has a cannula 1 which is telescoped over a stylet 2. The cannula has a sharp cutting edge at its leading end whereas the leading end of the stylet has a pointed tip. At a small distance behind the tip the stylet has a notch 3 which forms a specimen collecting recess.

The biopsy needle comprises a handle 5 including a pistol grip 6 which is shaped to be held conveniently between the fingers and palm of one hand,- and a barrel 7 which is of a generally rectangular, hollow configuration. Received in the barrel for axial sliding movement are a pair of sliders, namely a first slider 8 which is fastened securely to the trailing end of the stylet 2 and a second slider 9 which is securely fastened to the trailing end of the cannula 1. The top and side walls of the barrel 7 are interrupted adjacent the rear end of the barrel and the sliders 8, 9, have flanges 10, 11 which project laterally in opposite directions through the opening so formed to define operating buttons for advancing the sliders, and hence the stylet and the cannula relative to the handle 5. The opening in the barrel extends over a greater length in the top wall than it does in the side walls and a cover 13 is fitted to close the forward end portion of the top wall opening. The cover 13 may be a separate lid or a hinged flap and may have a snap fit with the barrel to secure it in the closed position. The sliders 8, 9, already preassembled with the stylet and cannula, can be introduced into the barrel when the cover is opened, and can then be locked in operative assembly with the

SUBSTITUTESHEET handle 5 by snapping the cover 13 onto the barrel 7. In use of the needle the sliders 8, 9 are initially adjusted to the fully retracted positions shown in Figures 2 and 3. The leading end of the needle is introduced into the body of the patient until it is adjacent the tissue mass from which the specimen is to be taken. During this step the thumb of the hand holding the pistol grip 6 is conveniently placed on^■the button portion 15 of the handle at the

_ rear end of the barrel for applying pressure longitudinally of the needle. The thumb is then moved to contact the flange 10 and push forwards the slider 8 until the flange abuts the stop provided by_.the end of the side wall of the barrel. In this way the slider 8 and the stylet are advanced to their forward end positions as illustrated in Figure 4. The notch 3 of the stylet is thus projected out of the cannula and receives a portion of the tissue mass from which the specimen is to be taken. The thumb is then transferred to the other side of the handle to contact the flange 11 and push forwards the slider 9 until it also reaches the forward end position determined by the flange abutting against the side wall of the barrel, as seen in Figure 5. The forward movement of slider 9 drives forwards the cannula 1 so that its leading edge cuts away the tissue portion received in the notch 3 and the specimen thus obtained is captured in the cannula. To remove the specimen the needle is withdrawn from the patient by pulling on the pistol grip 6 while the sliders 8, 9 remain in their forward end positions.

As shown the slider 9 includes a lip 16 which cooperates with a shoulder 17 on the slider 8 to ensure that the two sliders can only be advanced in the correct sequence as described. To further assist

SUBSTITUTESHEET correct operation the three thumb buttons formed by the handle portion 15, flange 10 and flange 11 can carry indications to signify the correct procedure, such as numbers 1 , 2, 3 (or I, II, III) or letters A, B, C, respectively. In addition, the slider 9 attached to the cannula could be provided with locking means (not shown) to prevent forward displacement of this slider relative to the handle until the locking means is released by the slider 8 being moved into its forwardmost position.

From the foregoing it will be understood that the instrument of the invention can be easily operated with one hand without demanding any special skill or dexterity.

_SUBSTITUTESHEET

Claims

CLAIMS : -

1. A biopsy instrument comprising first and second members (8, 9) slidable relative to each other and fastened to respective elongate parts (1, 2) to be advanced and retracted in the performance of a biopsy procedure, characterised in that a handle (5) is provided, the first and second members (8, 9) being carried by the handle for linear sliding movement.

2. A biopsy instrument according to claim 1, wherein the handle (5) comprises a pistol grip (6).

3. A biopsy instrument according to claim 1 or 2, wherein the handle (5) comprises a barrel (7), the slide members (8, 9) being received in the barrel and being guided thereby for sliding movement longitudinally of the barrel.

4. A biopsy instrument according to claim 1, 2 or 3, wherein the barrel is of substantially rectangular configuration.

5. A biopsy instrument according to claim 3 or 4, wherein the barrel (7) has a cover (13) said cover being openable to permit insertion and removal of the slide members (8, 9).

6. A biopsy instrument according to claim 5, wherein the cover (13) has a snap fit connection with the barrel.

7. A biopsy instrument according to any one of the preceding claims, wherein the slide members (8, 9) have respective actuating elements (10, 11) projecting outwardly of the handle.

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8. A biopsy instrument according to claim 7, wherein the actuating elements (10, 11) project laterally from opposite sides of the handle.

9. A biopsy instrument according to any one of claims 3 to 6, wherein the slide members (8, 9) are located alongside each other in the barrel and each has a respective actuating element (10, 11) protruding outwardly through an opening in the adjacent side wall of the barrel.

10. A biopsy instrument according to any one of claims 3 to 6 or 9, wherein the barrel defines stop means for limiting the forward and rearward sliding movement of the slide members.

11. A biopsy instrument according to any one of claims 3 to 6, 9 or 10, wherein the barrel has a rear end wall forming a button portion (15) for use in introducing the instrument into a patients body.

12. A biopsy instrument according to any one of the preceding claims, wherein stop means (16) are provided to prevent the second slide member (9) being slid forwards before the first slide member (8).

13. A biopsy instrument according to claim 12, wherein the stop means is an abutment (16) arranged on the second slide member (9) for engaging the first slide member (8).

14. A biopsy instrument according to claim 12, wherein the stop means is a locking device arranged to lock the second slide member (9) against forward displacement until the first slide member has been advanced to a forward end position.

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15. A biopsy instrument according to any one of the preceding claims, wherein the handle (5) the first slide member (8) and the second slide member (9) have indicia thereon to indicate the correct operative procedure for manipulation of the instrument in taking a tissue specimen.

16. A biopsy instrument according to any one of the preceding claims, wherein the parts fastened to the first and second slide members (8, 9) are a stylet (2) and a cannula (1), respectively, the instrument being a biopsy needle.

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