MX2008000667A

MX2008000667A - Needle for soft tissue biopsy.

Info

Publication number: MX2008000667A
Application number: MX2008000667A
Authority: MX
Inventors: Giorgio Calanca; Nicola Baroni; Davide Sacchetti; Nicola Vezzani
Original assignee: Medax S R L
Priority date: 2005-07-15
Filing date: 2006-07-10
Publication date: 2008-03-14
Also published as: BRPI0613061A2; ITMO20050182A1; WO2007009901A1; EP1903945A1

Abstract

A semiautomatic needle (1) for soft tissue biopsy, comprising a body (2) and a slider (3) which can slide with respect to the body by way of the action of elastic means, means for actuating the sliding of the slider, a stylet (4) which is slidingly associated with the body (2), which is accommodated in a through hole formed in the slider (3) and has a grip end (4a) and an opposite end (4b) for removing a tissue sample, a cannula (6) inside which the stylet (4) is accommodated so that it can slide axially and which has a proximal end (6a) which is detachably associated with the slider (3) and a distal end (6b) which is adapted to be inserted in the body of the patient, means for temporary retention of the proximal end of the cannula with the slider (3) which comprise a locking ring (7), means (11) for temporarily locking the relative rotation between the cannula and the slider being provided.

Description

NEEDLE FOR A BIOPSY OF SOFT TISSUE TECHNICAL FIELD The present invention relates to a needle for a soft tissue biopsy.

TECHNICAL BACKGROUND In the field of medical diagnostic procedures, with particular reference to biopsies, it is known to use semi-automatic needles that allow the removal of soft organic tissues to be analyzed from a patient's body. Among the various types of semiautomatic needles for biopsies, the use of a so-called guillotine needle has been known for some time. This needle is constituted by a body provided with a hand piece and a slider that can slide with respect to the body by means of the action of a spring. A stylet is slidably related to the body and inserted into a through hole formed in the slider. The stylet has an end provided with a holding knob and an opposite end that is pointed out and provided with a notch to collect a tissue sample that is taken from the body of a patient. A cannula is fixed to the slider at an axial end thereof, which is generally referred to as the proximal end with respect to the doctor or health operator performing the biopsy. The cannula slidably accommodates the stylet, and its end that lies opposite the proximal end, known as the distal end, is sharp and adapted to be inserted into the body of a patient. The method of using said needle is provided for a first step wherein the slider is moved toward, and locked in, a spring loaded position. The doctor or health care provider then performs the percutaneous penetration of at least a portion of the cannula into the body of a patient after local anesthesia and with constant sonogram monitoring of the patient, placing the distal end of the cannula in the patient's body. closeness of the soft tissue region to be analyzed. Once the intended placement of the cannula has been achieved, a pressure from the doctor / health operator on the clamping knob causes the pointed end to extend along with the pick-up notch of the stylet from the distal end of the cannula, cutting part of the tissue, which in turn is arranged in the collection notch. An additional pressure on the clamping knob releases the slider which, as a consequence of the action of the spring, causes the advance of the cannula until the stylet is completely covered, consequently cutting and retaining the portion of tissue disposed inside the collection notch. . At this point, the needle can be removed from the patient's body. If it is necessary to collect a plurality of samples in the soft tissue region, it is known to use the so-called coaxial needles in order to avoid extractions and successive insertions of biopsy needles. The coaxial needles are constituted by a tubular element, whose internal diameter is greater than the diameter of the cannula of the semi-automatic needle where a stylet is inserted to block the internal opening. The doctor / health operator inserts the coaxial needle into the patient's body until a sample is taken from the soft tissue region, the locking stylet is removed, and the semi-automatic needle cannula is inserted into the tubular element. In this way, successive tissue samples can be taken while holding the coaxial needle in position, with an approach that is relatively less invasive for the patient. Those known biopsy needles are not free of drawbacks, which include the fact that performing a plurality of biopsies, requires the additional use of the coaxial needle, which covers higher supply costs for the health organization and complicates the operations performed by health operators. In addition, the larger diameter of the coaxial needle with respect to the diameter of the semi-automatic needle cannula makes the procedure more invasive for the patient. As an alternative for the use of coaxial needles, semiautomatic needles are known in which the cannula is releasably related to the slider. In this way, once the tissue sample has been collected, the cannula is decoupled from the slider and the stylet is removed. The cannula remains inserted in the patient's body with its distal end, which is located next to the soft tissue region to be sampled and for subsequent sampling it is sufficient to insert the stylet again. The semiautomatic needles are also known which have a removable cannula where the proximal end of the cannula engages the slider with a threaded coupling of the Luer-Lok type and wherein said cannula is uncoupled when rotated with respect to the slider. These needles are not free of drawbacks: the procedure for decoupling the slider cannula requires a rotation thereof within the patient's body, with a high risk of internal lacerations and tissue damage involved in subsequent sampling.

Semi-automatic needles with a removable cannula are also known in which detachment of the body cannula occurs when actuating actuators such as buttons or levers. However, even these needles have drawbacks. During the procedure for taking the tissue sample, an unintended detachment of the cannula from the needle body may occur particularly due to accidental impacts by the doctor / operator with said buttons or levers or as a consequence of cannula stresses caused by the advance for cutting the tissue sample.

BRIEF DESCRIPTION OF THE INVENTION The aim of the present invention is to eliminate the aforementioned drawbacks of the prior art, by providing a semi-automatic needle that ensures a stable and secure coupling of the cannula during the execution of the biopsy. An object of the present invention is to ensure a detachment of the slider cannula that is simple and easy to perform, that does not injure the patient and is not additionally invasive for the patient. Within this aim, another objective of the present invention is to provide a needle that is simple, relatively easy to provide in practice, safe to use, effective in operation and having a relatively low cost.

This objective and other objects that will be apparent hereinafter are achieved by the semiautomatic needle of the present for a soft tissue biopsy, comprising a body and a slider that can slide with respect to the body by means of the action of elastic means. means for actuating the sliding of the slider, a stylet that is slidably related to the body, which is accommodated in a through hole formed in the slider and having a gripping end and an opposite end to remove a tissue sample, a cannula within which the stylet is accommodated so that it can slide axially and having a proximal end that is releasably related to the slider and a distal end that is adapted to be inserted into the patient's body, means for retention of the proximal end of the cannula with the slider are provided, characterized in that the temporary retention means comprise of a locking ring, means are provided to temporarily block the relative rotation between the cannula and the slider.

BRIEF DESCRIPTION OF THE DRAWINGS Additional features and advantages of the present invention will be apparent from the following detailed description of a preferred but not exclusive embodiment of a semi-automatic needle for soft tissue biopsy, which is illustrated by way of a non-limiting example in the accompanying drawings, in where: Figure 1 is a plan view of the biopsy needle according to the invention and of the respective cannula; Figure 2 is a plan view of the biopsy needle according to the invention, wherein the cannula is partially inserted into the stylet; Figure 3 is a plan view of the biopsy needle according to the invention, wherein the cannula is related to the body of the needle; Figure 4 is a view of a detail of the biopsy needle according to the invention.

DETAILED DESCRIPTION OF THE INVENTION With reference to the figures, reference number 1 generally designates a semi-automatic needle for soft tissue biopsy. The needle 1 comprises a body 2 with which it relates a slider 3 that can slide, by means of the action of elastic means, from a position that is contracted with respect to the body 2 to a position that extends towards the exterior of the body 2 , or vice versa, means provided to actuate the sliding of the slider 3, said means are not shown in detail in the figures. A stylet 4 is slidably related to the body 2 and accommodates in a through hole formed in the slider 3. The stylet 4 has a holding end 4a, which is provided with a knob 5 and disposed opposite a end 4b to remove a tissue sample. In particular, the knob 5 is related so that it can slide with respect to the slider 3 and is adapted to be held by an operator or doctor. The traction is applied to the knob 5 in order to place the slider 3 in a contracted position, loading the elastic means. Subsequent pressure by a doctor / health operator on the knob 5 causes the sliding of a portion of the stylet 4 with respect to the slider 3 and the subsequent actuation of the activation means, with the release of the elastic means acting to slide the slider 3 from the contracted position to the extended position. The sampling end 4b is substantially marked and provided with a notch 4c to collect the tissue sample. A cannula 6 is adapted to internally accommodate the stylet 4 so that it can slide axially with respect to the cannula, and have a proximal end 6a, which is releasably related to the slider 3 by means of the temporary retention means.

The term "proximal" is used to refer to the position of said endpoint with respect to the doctor or health operator who holds the needle 1 in order to perform the biopsy. A distal end 6b of the cannula 6 that is opposite the proximal end 6a is sharp and adapted to be inserted into the body of a patient in order to place it close to the region of the soft tissue to be sampled. In addition, the sampling end 4b is adapted to exit the distal end 6b to subsequently cut and retain a soft tissue sample within the collection notch 4c. The retaining means comprises a locking ring 7, which is rotatably related to the slider 3 or the proximal end 6a and is provided with the first threaded means 8 to engage with the second threaded means 9 formed in the slider 3 or the proximal end 6a, respectively. With reference to the preferred but non-exclusive embodiment of the invention that is considered, the locking ring 7 is rotatably related to the slider 3 and the first threaded means 8 comprises a thread that is disposed within the ring 7. The second means threaded 9 comprises an external thread, which is formed at the proximal end 6a.

In particular, the slider 3 comprises a portion extending from the body 2 and is provided with a tongue 10 for coupling the cannula 6, which is substantially tubular. The through hole accommodating the stylet 4 is formed at the outer end of the coupling tongue 10. Conveniently, the proximal end 6a of the cannula 6 is constituted by a support made of plastic material which is substantially tubular and which comprises at least one portion 6c for the insertion of the coupling tongue 10. The locking ring 7 comprises a hollow and substantially cylindrical element, which opens at its opposite ends and is provided, at one end, with the first threaded means 8 and, in the opposite end, with an annular edge 7a, which is rotatably and playfully related to the slider 3 in the groove 10a that is formed in the coupling tongue 10. The coupling tongue 10 also has means for stopping the axial sliding of the locking ring 7 with respect to the slider 3, comprising an annular collar 10b, extending towards the center on the outer surface of the coupling tongue 10, and a shoulder 10c, which is formed by means of the wall of the extending portion of the slider 3 from which the coupling tongue 10 extends. The slot 10a is delimited by the collar 10b and by the shoulder 10c.

The needle 1 further comprises means for temporarily blocking the relative rotation between the cannula 6 and the slider 3, which are formed in the coupling tongue 10. In particular, the means for temporarily blocking the rotation comprises a lateral adjustment coupling between the tongue coupling 10 and the proximal end 6a of the cannula 6. The lateral adjustment coupling comprises a longitudinal slot 11, which is formed on the inner surface of the insertion portion 6c and can be coupled to a corresponding longitudinal rib 12, which extends from the outer surface of the coupling tongue 10. The operation of the needle according to the present invention is as follows. First, the semi-automatic needle 1 for multiple soft tissue binoxies is prepared by a doctor or health care operator for use when loading elastic means, by placing the slider 3 (and the cannula 6 connected thereto) in the contracted position with respect to to the body 2. The load occurs by pulling the knob 5 fixed to the stylet 4. At least a portion of the cannula 6 is inserted into the patient's body 2, placing the distal end 6b close to the region of the soft tissue to be analyzed. A pressure from the doctor / health operator on the knob 5 causes the stylet 4 to slide relative to the slider 3, causing the extension end 4b to exit the distal end 6b and arranging at least a portion of the soft tissue within the collection groove 4c. An additional pressure from the doctor / health operator on the knob 5 activates the activation means, releasing the slider 3, which slides, by means of the action of the elastic means, from the contracted position to the extended position. This encompasses the sliding of the distal end 6b of the cannula 6 at the sampling end 4b, cutting the tissue sample disposed within the picking groove 6c and retaining it within the needle 1. In doctor / operator of the salute the ring rotates of blocking 7 in order to uncouple the first and second threaded means 8 and 9, and during this rotation the coupling between the longitudinal groove 11 and the longitudinal rib 12 engages the proximal end 6a to the coupling tongue 10 preventing rotation of the cannula 6 rigidly with the locking ring 7. The stylet 4 is then removed from the cannula 6 together with the tissue sample. In order to perform successive biopsies in the same patient and in the vicinity of the same soft tissue region, the stylet 4 is inserted again into the cannula 6, the longitudinal groove 10a is placed in the longitudinal rib 12, and the locking ring 7 is rotated to engage between the first and second threaded means 8 and 9. It has been found in practice that the described invention achieves the intended purpose and objectives, and in particular emphasis is placed on the fact that fixing the The cannula to the slider by means of the locking ring ensures a stable and secure coupling of the cannula during the execution of the biopsy. In addition, detachment and locking of the cannula with respect to the slider by rotation of the locking ring is simple and easy to perform and the presence of the means to block the relative rotation between the cannula and the slider prevents unwanted rotations of the cannula within the cannula. patient's body, avoiding tissue injuries and limiting the invasion of these detachment and block maneuvers. The invention in this conceived manner is susceptible to numerous modifications and variations, all of which are within the scope of the appended claims. All the details can be replaced in addition with other technically equivalent elements. In practice, the materials used, as well as the contingent forms and dimensions, can be in accordance with the requirements without abandoning the scope of the protection of the appended claims. The descriptions in the Italian patent application No. MO2005A000182 from which this application claims priority are incorporated herein by reference.

Claims

NOVELTY OF THE INVENTION CLAIMS

1. A semiautomatic needle for soft tissue biopsy, comprising a body and a slider that can be slid with respect to the body by means of the action of elastic means, means for actuating the sliding of said slider, a stylet that is slidably related with said body, which is accommodated in a through hole formed in the slider and having a clamping end and an opposite end to remove a tissue sample, a cannula into which the stylet is accommodated so that it can slide axially and having a proximal end that is detachably related to the slider and a distal end that is adapted to be inserted into the patient's body, means for temporarily retaining the proximal end of said cannula with the slider are provided, characterized in that the means of temporary retention comprises a locking ring, means are also provided for temporarily blocking the rotation r elativa between said cannula, and said slider.

2. The needle according to claim 1, further characterized in that said locking ring is rotatably related to the slider or said proximal end of said cannula and is provided with the first threaded coupling means, corresponding to the second threading means formed in the slider or said proximal end of the cannula, respectively.

3. The needle according to claim 1 or 2, further characterized in that the locking ring is rotatably related to said slider and that said first threaded means comprises a thread disposed inside the locking ring, said second threaded means comprises an external thread formed at the proximal end of the cannula.

4. The needle according to one or more of the eding claims, further characterized in that the locking ring comprises a hollow cylindrical element, which opens at its opposite ends and is provided, at one end, with said first threaded means, at the opposite end, with an annular edge, which is rotatably related to the slider, means are also provided to stop the axial sliding of said ring with respect to the slider.

5. The needle according to one or more of the eding claims, further characterized in that the slider comprises a tongue for coupling the cannula that is adapted to be inserted into the proximal end of the cannula, said means for temporarily blocking the cannula. Relative rotation are formed on the tongue.

6. The needle according to one or more of the eding claims, further characterized in that the means for temporarily blocking the relative rotation comprise a lateral adjustment coupling between the tongue and the proximal end of the cannula.

7. The needle according to one or more of the eding claims, further characterized in that the lateral adjustment coupling comprises a longitudinal groove formed within the proximal end and a corresponding longitudinal rib extending from the external surface of the tongue.

8. The needle according to one or more of the eding claims, further characterized in that the tongue comprises a groove with which the edge is connected in a rotatable manner and can play.

9. The needle according to one or more of the eding claims, further characterized in that the means for stopping the axial sliding of the ring comprises a shoulder and a collar, which are formed in the tongue and delimit said groove.