BIOPSY NEEDLE

Abstract: A biopsy needle for removal of tissue from human or animal bodies incorporates an elongated body (1) pointed at one end and a tissue-removing edge directed backwardly from the pointed end and formed on a flap (9) supported by the body (1) and movable between a retracted position in which the tissue-removing edge lies within the lateral confines of the body (1) and an extended position in which the tissue-removing edge lies beyond the lateral confines of the body (1). The flap (9) is mounted on a plunger (7) slidable and rotatable within the body (1) the wall of which is formed with an aperture (2) with which the flap may be brought into register by movement of the plunger (7). The needle is used by inserting it into the tissue, extending the flap to entrain a portion of tissue, retracting the flap and withdrawing the plunger from the body, bringing with it the portion of tissue.

Description: BIOPSY.NEEDLE The subject of this invention is a needle for performing biopsies i .e. for removal of pieces of tissue from human or animal bodies. The needle which is the subject of this application is of particular use in performing pleural biopsies. Needles for performing biopsies are already well known and such known needles normally comprise a probe whi ch carries near the distal end a scoop projecting from the side of the probe, a biopsy being performed by inserting the probe through an incision made in the s in and pressing the probe into the body far enough for the scoop to reach the portion of the body from which a portion is to be removed. The probe is then withdrawn, the scoop entraining a portion of the tissue of the body and as the probe is removed this portion of tissue held by the scoop is brought back out for medical examination. The known biopsy needles suffer from the disadvantage that thei r results are extremely unpredi ctable and in fact usually a suitable portion of tissue is removed in little more than 70% of such biopsy operations. Even when a satisfactory portion of tissue is removed this frequently is accompanied by a piece of unwanted tissue. Also the probe may cause more damage than necessary to surrounding tissue and if the ti ssue sample obtained is unsatisfactory the needle must be re-inserted into the body and a fresh attempt made to obtain a satisfactory tissue sample. It is an object of the present in ention to provide a biopsy needle whi ch gives a higr, αegree of success in removing satisfactory samples at a fi rst attempt, a success rate normally well aoove 90% and which will readily remove cleanly a sample of wanted tissue without dragging with it port on's of unwanted tissue. A biopsy needle according to the invention incorporates an elongated body pointed at one end and a tissue-remov ng edge directed backwardly from - the po nted end and s characterized in that the tissue-removing edge is formed on a flap supported by the body and movable between a retracted posit on - in w ch the t ssue-remov ng edge lies ithin the lateral confines of the body and an extended posit on in which the tissue-removing edge lies beyond the lateral confines of the body. The proximal end of the needle., i.e. the end remote from the pointed end, may be forme-d as' a handle supporting operating means" coupled to tire flap and operative to move the flap from the retracted position to the extended position and vice versa.. The operating means may include, locking means to lock the flap in the chosen position. The flap may be formed as a flat flap or may be curved in the form of a scoop. The tissue-removing edge may be formed as a straight edge or may be formed with serrations. The tubular body may be circular or eLliptrcal or polygonal in cross section. The flap may be mounted on a plunger slidablε within the tubular body the wall of which in th s construction is formed with an aperture with whic the flap may be brought into register oy ar appropriate sliding movement of tre plunger. The flap may be pivoted at one end to the plunger and may be spring-urged to swing outwardly from the plunger, the tissue-removing edge being at the end of the flap remote from the pivot. In one alternative construction the flap is formed of spring material, s formed at one end ith the tissue- removing edge and is attached at the other end to the plunger, the flap being shaped to tend to spring outwardly from the plunger. The interior of the tubular body may have a ci rcular cross section and the plunger may be rotatable as well as slidable in the tubular body. The handle may be tubuLar and may thereupon be formed ith a slot having two axially disposed portions ci rcumferentially spaced and connected at thei r distal ends by a ci rcumferential portion, one of the axially disposed slot portions being open at its proximal end, and the plunger presents a pin engaging the slot, the position of the pin on the plunger and the positions of the various portions of the slot with respect to the tubular body being such that when the pin on the plunger is engaged with the open ended axial portion of the slot the flap is circumferentially displaced from the aperture in the tubular body. The length of said axial portion is such that when the pin is at the distal end of the slot portion the flap is nearer the distal end of the tubular body than the aperture whi le being sti ll ci rcumferentially displaced from the aperture. Rotating the plunger so that the pin moves along the ci rcumferential portion of the slot to the end where it joins the axial portion of the slot brings the flap into line with the aperture althoug the flap is sti ll nearer tne distal end of the tubular -4- body than the aperture, then retracting the plunger along said other axial portion of the s lot towards the proximal end of the slot brings rhe flap i n σ . register with the aperture in the ' tu.bu.l_ar body "ar*d ~ - ' frees the flap to swing out and project * through the aperture. The pointed tip on the needle may be formed on the distal end of the tubular body which has then a closed d stal end or may be formed on the d stal end of the plunger whereupon the distal end of the tubular body is open to allow the pointed end of the plunger to protrude when the needle is being inserted. A practical embodiment of the invention is i llustrated in the accompanying -drawings in which Fig. 1 illustrates a tubular body portion of the needle, Fig. 2 i llustrates a plunger movable" throu h the tubular body portion. Fig. 3 i llustralres an assembled biopsy needle with the flap in the extended position and Fig. 4 s an enlarged view of the distal end of the plunger. In the drawings 1 denotes a tubular body formed with a slot 2 in the wall near the distal end of the body 1 and 3 denotes a handle attached to the tube 1, the handle 3 being formed with a slot with two axial portions 4 and 5 joined at the distal ends of the slots by a ci rcumferential portion 6~. 7 denotes a plunger slidable through the tubular body portion 1, the plunger being pointed as at 8 at the distal end and carrying a flap 9 pivoted at 10 to the plunger 7. The fLap 9 is a commodateα in a recess 11 n the plunger 7 Large enough to hold the flap 9 with n the d ametral confines of the plunger 7 when the flap is folded downwardly towards the plunger 7. The flap is normally urged by a spring 12 (Fig. 4) to move to the extended position as i llustrated. The plunger presents a pin 13 engageable with the slot constituted by the portions 4, 5 and 6 in the handle of the body portion 1. The arrangement of the pin 13 and of the slot 4, 5, 6 being such that when the plunger 7 is inserted into the body portion 1 and moved towards the distal end of the body portion 1, in the initial act of entering the plunger 7 into the body portion 1 the flap is forced to move into the recess 11 as the distal end of the plunger 7 moves through the body portion 1 towards the' distal end of the body portion 1. The plunger 7 is rotated to cause the pin 13 to enter the slot portion 4. In this orientation of the plunger 7 the flap 9 is out of line with the slot 2 in the body portion 1, i .e. it is displaced ci rcumferentially from the slot 2. As the plunger 7 is advanced to the position where the pin 13 comes against the distal end of the slot portion 4 adjacent the slot portion 6 the plunger is now n a position in which the flap -9 is nearer the distal end of the body portion 1 than the slot 2 but is sti ll retained in its retracted position by the wal l of the tubular body portion 1. The plunger 7 is now rotated to cause the pin 13 to move along the circumferential slot 6 unti l it is opposite the slot portion 5. In this position the flap 9 is in line with the slot 2 in the body portion 1 although sti ll nearer the distal end of the body portion 1 than the slot 2 and sti l l retained in its retracted position. Withdrawal of the plunger 7 causing the pin to move along the slot portion 5 causes the flap 9 to move back from the distal end of the body portion 1 unti l it now registers ith the slot 2 in the body portion 1 whereupon the spring 12 causes the flap 9 to extend out t.hrαugh - the slot 2. In performing a biopsy the needle with the flap 9 out of register with the slot 2 is entered into the organ from w ich a tissue sample is to be taken through an incision made in the skin and when the distal end is at the position in the body where a sample is to be taken the movements described above to cause the flap 9 to protrude from the body portion 1 are performed. Thereupon the needle is withdrawn for a short distance to cause the flap 9 to remove and entrain a portion of the tissue of the organ. The plunger 7 is now advanced again towards the distal end of the body portion. The pin 13 is moved along the slot portion 5 up to the circumferential slot 6. This again causes the flap 9 to come against the forward end of the slot 2 and to retract and enter the recess 11, taking with it the portfon of - tissue removed. The plunger is then rotated -so that ; the pin 13 moves along the circumferential slot 6 until it is opposite the slot portion 5. This again brings the retracted flap 9 out of alignment with the sLot 2 in the body portion 1. The pLunger 7 may then be withdrawn completely from the body portion 1, the pin 12 moving along and out of the slot portion 5. Complete removal of the plunger 7 brings with it the portion of tissue removed by the flap 9 Leaving the body portion 1 still projecting into the organ. The sample removed by the flap 9 may now be examined. If it is satisfactory t e body portion 1 may be removed fro the body without further damage to the body. If the portion of tissue removed s not satisfactory the plunger 7 may be re-inserted as before and a fresh sample taken. It may be desi red to take several samples at different depths n the body. This can be done merely by pressing the needle different distances into the body. All this may be done as an operation with' only one insertion of the needle so that the minimum of damage is done to the organ and at the same time the samples removed can be seen to be completely satisfactory for clinical purposes before the needle is removed.

Claims: CLAIMS 1. A biopsy needle incorporating an' elongated body (1) pointed at one end and a ti ssue-removi rig edge directed backwardly from the pointed end ' characterized in that the tissue-removing edge is formed on a flap (9) supported by the body (1) and movable between a retracted position in which the t ssue-removing edge Lies within the Lateral confines of the body (1) and an extended position in which the tissue-remov ng edge Lies beyond the lateral confines of the body (1). 2. A iopsy needle according to cla m 1, characterized in that the proximal end of the needle, i.e. the end remote from the pointed end, is formed as a handle C3) supporting operating means (7) coupled to the flap (9) and operative to move the flap from the retracted position to the extended position and vice versa. 3. A biopsy needle according to claim 1, characterized in that the elongated body (1) is tubular and has a circular cross section and the plunger (7) is rotatable as well as slidabLe in the tubular body (1 ) . 4. A biopsy needle according to cla 1, character zed in that the flap C9) is mounted' on a pLunger (7) slidabLe within the tubular body (1) the wall of which is formed with an aperture (2) with which the flap may be brought into register by an appropriate sliding movement of the plunger ( 7 ) . 5. A biopsy needle according to claim 4, character zed n that the flap (9) is spring-urged to swing outwardly from the plunger, the tissue-removing edge being at the end of the flap remote from the pivot (10) . 6. A biopsy needle according to claim 4, characterized in that the flat (9) is of spring material, is formed at one end with the tissue-removing edge and is attached at the other end to the plunger (7), the flap being shaped to tend to spring outwardly f rom the p Lunge r . 7- A biopsy needle according to claim 2, characterized in that the handle (3) is tubular and formed with a slot (4, 5, 6) having two axially disposed portions (4 and 5) circumferentially spaced and connected at thei r distal ends by a ci rcumferential portion (6), one of the axially disposed slot portions (4) being open at its proximal end, and the plunger (7) presents a pin (13) engaging the slot, the position of the pin (13) on the plunger (7) and the positions of the various portions of the slot with respect to the tubular body (1 ) being such that when the pin (13) on the plunger is engaged with the open ended axial portion (4) of the slot the flap (9) is circumferential ly displaced from the aperture (2) in the tubular body and when the pin (13) is engaged with the other axial portion (5) of the slot the flap (9) is in Line with the aperture (2) in the tubular body and is movable into register with the aperture (2) . 8. A biopsy needle according to claim 1, characterized in that the operating means includes locking means to lock the flap (9) in the chosen position. 9. A biopsy needle according to claim 1, characterized in that the flap (9) is curved in the form of a scoop. 10. A biopsy needle according -to cla m 1 , characterized in that the tissue-removing edge' is formed with serrations.

Inventors: OGIRALA RAJA GANAPATHY, OGIRALA, RAJA, GANAPATHY
Applicants: COATS VIYELLA MEDICAL LTD, COATS VIYELLA MEDICAL LIMITED
Application year: 1988
Main classification: A61B10
IPC codes: A61B10, A61B17