BIOPSY NEEDLE

Abstract: A biopsy needle (1) comprising mandrel means (2;22) a distal end of which is provided with a tip (3;26;28) near which at least one housing (5;23;25) is obtained suitable for receiving a tissue sample to be drawn, hollow needle means (4) slidingly coupled with the outer surface of said mandrel means (2), pushing means (6,8) capable of cause said hollow needle means (4) to slide on said spindle means (2) along a preestablished direction (F2), stop means (9,10) capable of engaging said pushing means (6,8) in order to prevent said hollow needle means (4) from sliding along said preestablished direction (F2), releasing means (14,15) for disengaging said stop means (9,10) from said pushing means (9,10), said biopsy needle (1) further comprising locking means (16) of said releasing means (14,15).

Description: BIOPSY NEEDLE The invention concerns a biopsy needle of the guillotine type, i.e. a tool designed to take samples from organs or tissues of patients, in order to diagnose the nature of a pathological process. The biopsy needle according to the present invention is suitable, particularly, for taking samples of soft and/or compressible tissues. From the prior art, biopsy needles of a type known as "guillotine needles" are known comprising a substantially cylindrical mandrel having an end near which a housing is provided - for example a housing obtained by flattening a portion of the mandrel - designed to receive a sample to be taken, and a hollow needle with a sharp point, said need being slidingly coupled with the outer surface of he mandrel. The housing has such dimensions as to receive a tissue sample having a size suitable for being used for histological tests. In order to effect a biopsy, the tool is introduced into the body of a patient, keeping the mandrel drawn back into the hollow needle so that only the point of the mandrel protrudes from the needle. When the point of the mandrel reaches the area of the patient body from which a sample is to be taken, the mandrel is driven out of the needle by sliding it with respect to the needle. In this way a portion of the tissue surrounding the mandrel penetrates into the housing provided in the mandrel. Then, the housing is covered by the hollow needle so that the sharp point of the hollow needle separates from the surrounding tissue, like a guillotine, said tissue portion penetrated in the housing. Biopsy needles are known in which the displacement of the hollow needle for covering the housing of the mandrel is obtained by using pushing means, for example elastic pushing means which may be driven by the operator. Said elastic push means are driven by releasing a stop element of said elastic means. Usually, the force required for releasing the stop element is very small, in order to avoid an unwanted displacement of the biopsy needle when said stop element is released. However, since only a small force is required to release the stop element, there is a risk that the operator releases the stop element fortuitously before positioning the biopsy needle in the patient body correctly, If the needle is not positioned correctly into the body of the patient, there may be the need to repeat the biopsy, which causes additional discomfort and pain for the patient. It is an object of the present invention to eliminate the disadvantages mentioned above. According to the present invention, a biopsy needle is provided comprising a substantially cylindrical mandrel, having a point near which a housing is provided designed to receive a sample of tissue to be taken, a hollow needle with a sharp point, slidingly coupled with the outer surface of said mandrel, pushing means capable of causing said hollow needle to slide on said mandrel, releasable stop means of said pushing means, releasing means of said stop means, characterized in that it further comprises locking means of said releasing means. Further advantages and characteristics of the present invention will result from the description that follows, said description being being only illustrative and non-limiting and being referred to the enclosed drawings, in which: Figure 1 is a longitudinal section of a biopsy needle according to the invention; Figure 2 is a longitudinal section of the biopsy needle of Figure 1 , taken through a plane perpendicular to the section plane of Figure 1 ; Figure 3 is a section like that of Figure 1 , showing a first operative position of the biopsy needle; Figure 4 is an enlarged detail of Figure 3; Figure 5 is a section like that of Figure 3, showing a second operative position of the biopsy needle; Figure 6 is an enlarged detail of Figure 5; Figure 7 is an enlarged detail of Figure 1 ; Figure 8 is the section VIII-VIII of Figure 1 , showing in detail the locking means according to the invention; Figure 9 is a longitudinal partial and interrupted section of a second version of a biopsy needle according to the invention; Figure 10 is the section X-X of the Figure 9; Figure 11 is a section like that of Figure 9, showing a third version of a biopsy needle according to the invention; With reference to the figures, the biopsy needle 1 according to the invention comprises piercing mandrel means 2, terminating at a distal end with a point 3, designed to make easier the penetration of the mandrel means 2 through the tissues of the patient body, and a needle hollow body 4, sliding on the mandrel 2. and having a sharp end 31 turned towards the point 3 of the mandrel 2. On the outer surface of the mandrel 2, near the point 3, a housing 5 is provided designed to receive the tissue sample to be taken for the biopsy, said housing having dimensions suitable for receiving a tissue sample of sufficient size for the having dimensions suitable for receiving a tissue sample of sufficient size for the histological tests to be performed on it. The mandrel 2 is fixed, at an intermediate portion thereof, to first support means 6 slidable inside driving means 7, having, for example, the shape of a box- shaped case. The sliding of support means 6 inside the driving means 7 is opposed by elastic means 8, for example a helical spring. The driving means 7 is equipped with an elastic pawl 9 provided with a pair of stop teeth 10 capable of engaging seats 11 , 12 provided in said first support means 6 for locking said first support means 6 in preestablished positions, for example in a first preestablished position and in a second preestablished position. A proximal end of the mandrel 2, opposite to the point 3, is fixed to second support means 13 slidingly coupled to said driving means 7 and equipped with coupling means 15 capable of removably coupling with said support means 6, and releasing the stop teeth 10 of the elastic pawl 9 from the seats 11 , 12 of the first support means. The second support means 13 is provided with a handle 14 allowing an operator to slide the second support means 13 in a direction parallel to the longitudinal axis of the mandrel 2. The second support means 13 is connected to locking means 16 capable of stopping said second support means 13 from sliding in the direction of arrow F1 (Figure 1 ) with respect to the driving means 7, in order to prevent the coupling means 15 from releasing the teeth 10 of the pawl 9 from the seats 11 , 12 of the first support means 6. The locking means 16 may comprise a spacer 16, that can be removably interposed between the second support means 13 and the driving means 7. The needle hollow body 4 is fixed to a support element 17 removably connected to said first support means 6 by means of a bayonet-joint 18. The support element 17 is provided with control wings 19 allowing an operator to release the needle hollow body 4 from the support element 17 and to drive it out of the mandrel 2. The mandrel 2 and the needle hollow body 4 may be isolated from the outer environment, before being used, by means of protection means 20, having for instance the shape of a cylindrical sheath. The driving means 7 may be provided with a handle 21 in order to make easier for an operator to handle the biopsy needle. The operation of the biopsy needle 1 according to the invention takes place in the following manner: the operator, after locating the region of the patient body from which a sample to be analyzed is to be taken, acts on the handle 14 of the second support means 13 causing the second support means 13 to slide, together with the mandrel 2, in the direction of the arrow F2 (Figure 1 ). While the second support means 13 and the mandrel 2 are sliding, the coupling means 15 links the second support means 13 and the first support means 6 together, causing the first support means 6 and the needle hollow body 4 to slide together with the second support means 13 until the teeth 10 of the elastic pawl 9 engage the seats 11 , or 12, of the first support means 6, locking said first support means 6 in a first preestablished position, or in a second preestablished position, respectively. The sliding of the first support means 6 in the direction of the arrow F2 causes a compression of the spring 8. After the first support means 6 has been locked in said first preestablished position, or in said second preestablished position, the needle hollow body 4 protrudes over the mandrel 2 leaving only the point 3 thereof free and covering the housing 5 completely (Figure 1 and 2). Now, the operator introduces the biopsy needle 1 into the patient body, until the point 3 of the mandrel 2 reaches the region from which a sample to be analyzed is to be taken. One the point 3 of the mandrel 2 has reached said region, the operator slides the second support means 13 in the direction of the arrow F1 , until the spacer 16 stops the sliding of the second support means 13, before the coupling means 15 releases the teeth 10 of the pawl 9 from the seat 11 , or 12. The sliding of the second support means 13 in the direction of the arrow F1 causes the mandrel 2 to come out of the needle hollow body 4 through a distance depending on the position at which the first support means 6 has been locked. For example, if the first support means 6 has been locked in said first preestablished position, the mandrel 2 comes out of the needle hollow body 4 uncovering only in part the housing 5 designed to receive the sample to be taken (Figure 3 and 4). On the contrary, if the first support means 6 has been locked in said second preestablished position, the mandrel 2 comes out of the needle hollow body 4 until the housing 5 is completely uncovered (Figure 5 and 6). The choice of the preestablished position at which the first support means 6 is to be locked depends on the dimensions of the tissue sample that is to be taken. It is possible to preestablish more than two positions for locking at which the first support means 6 may be locked, in order to allow the biopsy needle 1 to take tissue samples of different dimensions. When the mandrel 2 comes out of the needle hollow body 4, a portion of the surrounding tissue, that will constitute the sample to be taken, enters the housing surrounding tissue, that will constitute the sample to be taken, enters the housing 5. At this point, the operator removes the spacer 16 and pushes again the second support means 13 in the direction of the arrow F1 , until the coupling element 15, interacting with the elastic pawl 9, disengages the teeth 10 from the seat 11 , or 12, releasing the first support means 6 from the second support means 13 and allowing the spring 8 to push suddenly the first support means 6, and the needle hollow body 4 in the direction of the arrow F1 , until the needle hollow body 4 covers the housing 5 completely, severing from the surrounding tissue, with its sharp end 31 , the tissue portion penetrated into the housing slot 5 and entrapping said tissue portion inside the needle hollow body 4. In order to recover the tissue sample after the biopsy needle 1 has been drawn out from the body of the patient, the needle hollow body 4 is released from the first support means 6 by rotating it by means of the wings 19, until the bayonet- joint 18 is disengaged from the first support means 6, and is drawn out from the mandrel 2, uncovering the housing 5 containing the tissue sample. In Figures 9 and 10 a second version of a biopsy needle according to the invention is shown, in which the mandrel 22 is provided with two oppositely disposed housings 23, 25 arranged symmetrically with respect to a longitudinal axis of the mandrel 22 and separated by a central region 24 of mandrel, said oppositely disposed housings 23, 25 being designed to receive two tissue samples to be analyzed. This makes possible to take two tissue samples to be analyzed in a single operation, allowing for a great reduction of patient suffering and time saving. The mandrel 22 terminates at a distal end with a point 26 provided with a flattened portion 27, forming a preestablished angle with respect to the longitudinal axis of the mandrel 22, said flattened portion 27 giving a so-called "flute nozzle" shape to the point 26, said shape making easier for the point 26 to penetrate into the tissues of the body of the patient. In Figure 11 a third version of a biopsy needle according to the invention is shown, in which the mandrel 22 is provided, as in the second version previously described, with two oppositely disposed housings 23, 25 separated by a central region 24 of the spindle. In this third version, the mandrel 22 terminates at a distal end with a point 28, provided with two flattened portions 29, 30 angled symmetrically with respect to the longitudinal axis of the mandrel 22, said flattened portions 29, 30 giving a symmetrical wedge-shaped configuration to the point 28, which is suitable for minimizing lateral bending of the mandrel, when the mandrel, when the mandrel is introduced into the body of the patient.

Claims: CLAIMS 1. Biopsy needle (1 ) comprising mandrel means (2; 22) a distal end of which is provided with a point (3; 26; 28) near which at least one housing (5; 23; 25) is provided designed to receive a sample of tissue to be taken, hollow needle means (4) slidingly coupled with the outer surface of said mandrel means (2), pushing means (6, 8) capable of causing said hollow needle means (4) to slide on said mandrel means (2) in a preestablished direction (F1 ), stop means (9, 10) capable of engaging said pushing means (6, 8) in order to prevent said hollow needle means (4) from sliding in said preestablished direction (F1 ), releasing means (14, 15) capable of disengaging said stop means (9, 10) from said pushing means (6, 8), characterized in that it further comprises locking means (16) of said releasing means (14, 15). 2. Biopsy needle according to the claim 1 , wherein said hollow needle means (4) is provided with a sharp end (31 ) at a distal end of said hollow needle means (4) turned towards said point (3; 26; 28) of said mandrel means (2), . 3. Biopsy needle according to the claim 1 , or 2, wherein a proximal end of said hollow needle means (4), opposed to said distal end, is removably coupled with first support means (6) slidably coupled with driving means (7). 4. Biopsy needle according to any of preceding claims, wherein said distal end of said hollow needle means (4) is fixed to a support element (17) coupled with said first support means (6) through bayonet-joint means (18). 5. Biopsy needle according to claim 4, wherein said support element (17) is provided with control means (19). 6. Biopsy needle according to any of claims 3 to 5, wherein said driving means (7) are shaped as a box-shaped case. 7. Biopsy needle according to any of claims 3 to 6, wherein said mandrel means (2) is fixed, at an intermediate portion thereof, to said first support means (6) 8. Biopsy needle according to any of preceding claims, wherein said pushing means (6, 8) comprises elastic means (8) connected to said first support means (6). 9. Biopsy needle according to claim 8, wherein said elastic means (8) is capable of exerting onto said first support means (6) a thrust directed towards said point (3; 26; 28) of said mandrel means (2). 10. Biopsy needle according to claim 8, or 9, when depending from claim 6, said point (3; 26; 28) of said mandrel means (2). 10. Biopsy needle according to claim 8, or 9, when depending from claim 6, wherein said elastic means (8) is inserted inside said driving means (7). 11. Biopsy needle according to any of claims 3 to 10, wherein a proximal end of said mandrel means (2) opposed to said point (3; 26; 28) is fixed to second support means (13) slidingly to said driving means (7). 12. Biopsy needle according to claim 11 , wherein said second support means (13) is provided with coupling means (15) capable of linking said second support means (13) to said first support means (6). 13. Biopsy needle according to any of preceding claims, wherein said stop means (9, 10) comprises elastic pawl means (9) connected to said driving means (7) and provided with at least one stop tooth (10) capable of engaging said first support means (6) 14. Biopsy needle according to claim 13, wherein said first support means (6) is provided with at least one seat (11 , 12) which may be engaged by said at least one stop tooth (10). 15. Biopsy needle according to any of claims 12 to 14, wherein said coupling means (15) is capable of interacting with said elastic pawl means (9) in order to disengage said elastic pawl means (9) from said first support means (6). 16. Biopsy needle according to any of preceding claims, wherein said locking means comprises removable spacer means (16) capable of preventing said coupling means (15) from interacting with said elastic pawl means (9). 17. Biopsy needle (1 ) comprising mandrel means (2) a distal end of which is provided with a point (3; 26; 28) near which at least one housing (5; 23, 25) is provided designed to receive a tissue sample to be taken, hollow needle means (4) slidingly coupled with the outer surface of said mandrel means (2), characterized in that said at least one housing (5; 23, 25) comprises at least two housings (23, 25) separated from each other. 18. Biopsy needle according to any of claims 1 to 16, wherein said at least one housing (5; 23, 25) comprises at least two housings (23, 25) separated from each other. 19. Biopsy needle according to claim 17, or 18, wherein said at least two housings (23, 25) are symmetrically arranged with respect to a longitudinal axis of said mandrel means (22). 20. Biopsy needle according to claim 19, wherein said at least two housings (23, 25) are separated by a central region (24) of said mandrel means (22). 21. Biopsy needle according to any of claims 17 to 20, wherein said point (26) is provided with a flattened portion (27) angled with respect to a longitudinal axis of the mandrel means (22) 22. Biopsy needle according to any of claims 17 to 20, wherein said point (28) is provided with two flattened portions (29, 30) angled substantially symmetrically with respect to a longitudinal axis of said mandrel means (22).

Inventors: GIUSTI DARIO, GIUSTI, DARIO
Applicants: GIUSTI DARIO, H S HOSPITAL SERVICE S R L, GIUSTI, DARIO, H.S. HOSPITAL SERVICE S.R.L.
Application year: 1999
Main classification: A61B10
IPC codes: A61B10