Needle tube and biopsy device

Abstract

A needle tube (3) has a tubular body (5). The body (5) has a slit (6) that extends in the longitudinal direction of the body (5) from a leading end opening (5c) of the body (5) toward the base end side and that penetrates the side wall of the body (5) in the radial direction. The length (L) from the leading end (5b) of the body (5) to the base end of the slit (6) is 3-25 mm. In a cross section perpendicular to the longitudinal axis (A) of the body (5), the opening angle (θ) formed by two line segments connecting the center (A) of the body (5) and side edges (6a, 6b) of the slit (6) on both sides in the width direction is 30-90°.

Description

Needle tubes and biopsy devices

[0001] The present invention relates to a needle tube and a biopsy device.

[0002] Conventionally, devices used for biopsy under ultrasound endoscopy, such as EUS-FNA / FNB (Endoscopic Ultrasound-guided Fine Needle Aspiration / Biopsy), have been known (see, for example, Patent Documents 1 and 2). The devices disclosed in Patent Documents 1 and 2 include a sheath that can be inserted into a treatment tool channel of an ultrasound endoscope, and a needle tube that can be inserted into the sheath and punctures biological tissue. The needle tube is thin, for example, with a diameter of less than 1 mm. In Patent Documents 1 and 2, a slit extending from the tip of the needle tube toward the base end is provided at the tip of the needle tube in order to increase the amount of biological tissue collected.

[0003] Patent No. 6097826 International Publication No. 2014 / 112518

[0004] As mentioned above, one of the challenges with biopsy needles is improving the amount of biological tissue collected. Collecting a large amount of tissue allows for the provision of a sufficient amount of specimen for various subsequent tests, contributing to improved accuracy of each test. To this end, improvements have been made to needles, as described in Patent Documents 1 and 2. However, biological tissue that contains a large amount of water is prone to slipping relative to the needle. Therefore, even if biological tissue is once introduced into the needle, it easily slips out of the needle when the needle is removed, making it difficult to collect a sufficient amount of tissue. Therefore, further improvements to needles are needed.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a needle tube and a biopsy device that can increase the amount of biological tissue collected.

[0006] One aspect of the present invention is a needle tube comprising a tubular body, the body extending longitudinally from a tip opening of the body toward a base end thereof and having a slit penetrating radially through a side wall of the body, the length from the tip of the body to the base end of the slit being 3 mm or more and 25 mm or less, and in a cross section perpendicular to the longitudinal axis of the body, the opening angle formed by two line segments connecting the center of the body to both side ends of the slit in the width direction is 30° or more and 90° or less.

[0007] Another aspect of the present invention is a biopsy device comprising a sheath, the above-mentioned needle tube provided within the sheath so as to be able to protrude from the tip of the sheath, and an operating unit provided on the base end side of the sheath for operating the sheath and the needle tube.

[0008] According to the present invention, it is possible to improve the amount of biological tissue that can be collected.

[0009] 1 is a diagram illustrating the overall configuration of a biopsy device according to an embodiment of the present invention. (a) is a front view and (b) is a cross-sectional view taken along line II-II of an example of a distal end portion of a needle tube. (a) is a front view and (b) is a cross-sectional view taken along line II-II of another example of a distal end portion of a needle tube. (b) is a diagram illustrating a method for collecting biological tissue using the biopsy device of FIG. 1, showing (a) a step of puncturing the biological tissue with the main body, (b) a step of rotating the main body, and (c) a step of removing the main body from the biological tissue. (a) is a diagram illustrating the operation of a slit with a short length L and (b) a slit with a long length L. (a) is a diagram illustrating the operation of a slit with a small opening angle θ and (b) a slit with a large opening angle θ. (b) is a table showing measurement results of the amount of collected biological tissue using multiple needle tubes. (a) is a front view and (b) is a cross-sectional view taken along line III-III of a distal end portion of a needle tube in which the slit has a narrow portion. (b) is a diagram illustrating the operation of a slit with a narrow portion and a slit without a narrow portion. 1A is a cross-sectional view of a needle tube in which the cutting edge of the slit blade is positioned at (a) the radially outer end and (b) the radially inner end. 2A is a diagram showing a modified example of the slit blade and (b) a modified example of the tip blade. 3A is a schematic diagram illustrating the positional relationship between the cutting edge and the slit when the main body of the needle tube is viewed from the tip side in the direction along the longitudinal axis.

[0010] A needle tube and a biopsy device according to one embodiment of the present invention will be described below with reference to the drawings. As shown in Figure 1, the biopsy device 1 according to this embodiment includes a sheath 2, a biopsy needle tube 3 disposed within the sheath 2, and an operating unit 4 provided on the proximal end side of the sheath 2 and the needle tube 3.

[0011] The biopsy device 1 is used in combination with an ultrasonic endoscope. The sheath 2 and the needle tube 3 are inserted into a treatment instrument channel of the ultrasonic endoscope, and the control unit 4 is disposed outside the ultrasonic endoscope. The tips of the sheath 2 and the needle tube 3 protruding from the tip of the ultrasonic endoscope are disposed within the field of view of the ultrasonic endoscope and are observed in optical images and ultrasonic images acquired by the ultrasonic endoscope.

[0012] The sheath 2 is a flexible, long, tubular member that is open at both end faces and has an outer diameter smaller than the inner diameter of the treatment instrument channel. The needle tube 3 has a flexible, long main body 5. The main body 5 is a circular tubular member that is open at both end faces and has an outer diameter smaller than the inner diameter of the sheath 2. The main body 5 is movable in the longitudinal direction relative to the sheath 2 and is rotatable around the longitudinal axis A of the main body 5 relative to the sheath 2.

[0013] 2(a) and 2(b) show an example of the shape of the distal end portion of the main body 5, and FIGS. 3(a) and 3(b) show another example of the shape of the distal end portion of the main body 5. The distal end surface 5a of the main body 5 is inclined with respect to the longitudinal axis A, and the distal end 5b of the main body 5 is a sharp needle tip. The main body 5 has a slit 6 at its distal end. The slit 6 extends longitudinally of the main body 5 from a distal end opening 5c ​​on the distal end surface of the main body 5 toward the base end and radially penetrates the side wall of the main body 5. The inside of the main body 5 is continuous with the outside of the main body 5 via the slit 6 and the distal end opening 5c. In the examples of FIGS. 2(a) and 3(a), the slit 6 is positioned 180° circumferentially around the longitudinal axis A relative to the needle tip 5b. However, as described below, the slit 6 may be positioned elsewhere (see FIG. 12).

[0014] Parameters determining the shape of the main body 5 include the length L and the opening angle θ. The length L is the length from the tip 5b of the main body 5 in the longitudinal direction to the base end of the slit 6 (see FIGS. 2(a) and 3(a)). The opening angle θ is the angle formed by two line segments connecting the side ends 6a, 6b on both sides in the width direction of the slit 6 to the center of the main body 5 (longitudinal axis A) in a cross section perpendicular to the longitudinal axis A (see FIGS. 2(b) and 3(b)). In the needle tube 3 of this embodiment, the length L is 3 mm or more and 25 mm or less, and the opening angle θ is 30° or more and 90° or less.

[0015] The product of the length L and the opening angle θ is preferably within a predetermined range. That is, as shown in Figures 2(a) and 2(b) and 3(a) and 3(b), the length L and the opening angle θ are inversely proportional to each other, and it is preferable that the opening angle θ is smaller as the length L increases. The predetermined range is set according to the dimensions, such as the inner diameter, and the shape of the main body 5.

[0016] The main body 5 preferably has a tip blade 7 provided on a tip surface 5a of the main body 5 and slit blades 8 provided on both side surfaces 6c of the slit 6 that face each other in the width direction. The tip blade 7 is formed by an inner circumferential surface 5d of the main body 5 and the tip surface 5a of the main body 5 that forms an acute angle with the inner circumferential surface 5d, and has a sharp cutting edge 7a at the radially inner end of the tip surface 5a.

[0017] As shown in Figures 2(b) and 3(b), the side surface 6c forms an acute angle with the outer peripheral surface 5e of the main body 5, and the radially outer end of the side surface 6c protrudes circumferentially further than the radially inner end of the side surface 6c. The slit blade 8 is formed from the side surface 6c and the outer peripheral surface 5e, and has a sharp cutting edge 8a at the radially outer end of the side surface 6c. The side surface 6c may also form an acute angle with the inner peripheral surface 5d, and the slit blade 8 may be formed from the side surface 6c and the inner peripheral surface 5d (see Figures 8(a) and (b)). In this case, the slit blade 8 has the cutting edge 8a at the radially inner end of the side surface 6c.

[0018] The operating section 4 is a section with which the operator operates the sheath 2 and the needle tube 3, and has a main body 9 and an operating member 10 provided on the main body 9. The main body 9 is made of a cylindrical member, and the sheath 2 and the proximal end of the main body 5 are housed inside the main body 9.

[0019] The operating member 10 is used to move the needle tube 3 relative to the sheath 2 and is a tubular member disposed on the outside of the main body 9. The operating member 10 is connected to the proximal end of the main body 5 and is movable longitudinally relative to the main body 9 and rotatable about the longitudinal axis of the main body 9. The operating member 10 may be fixed to the sheath 2 by a fixing member 10a such as a thumbscrew. By pushing the operating member 10 toward the distal end, the operator can advance the main body 5 toward the distal end and cause the needle tip 5b to protrude from the distal end of the sheath 2. In addition, by pulling the operating member 10 toward the proximal end, the operator can retract the main body 5 toward the proximal end until the needle tip 5b is retracted into the sheath 2.

[0020] The operating unit 4 may further include another operating member 11, a suction port 12, and a stylet 13. The operating member 11 is used to move the sheath 2 relative to the main body 9, is connected to the proximal end of the sheath 2, and is movable in the longitudinal direction relative to the main body 9. The suction port 12 opens at the proximal end of the main body 9, communicates with the interior of the main body 5, and can be connected to a suction tool such as a syringe. The stylet 13 can be inserted into the main body 5 through the suction port 12.

[0021] Next, the functions of the needle tube 3 and the biopsy device 1 will be described. The biopsy device 1 is used in combination with an ultrasonic endoscope for EUS-FNA / FNB (Endoscopic Ultrasound-guided Fine Needle Aspiration / Biopsy). As shown in Figures 4(a) to 4(c), a method for collecting biological tissue using the biopsy device 1 includes step S1 of puncturing the biological tissue T with the main body 5, step S2 of rotating the main body 5, and step S3 of removing the main body 5 from the biological tissue T.

[0022] Prior to step S1, an ultrasonic endoscope is inserted into a body cavity and positioned at a position where a target biological tissue T, for example, a pancreatic tumor, is to be observed. Next, a sheath 2 accommodating a needle tube 3 is inserted into a treatment instrument channel of the ultrasonic endoscope, and the tip of the sheath 2 protruding from the distal opening of the treatment instrument channel is positioned at an appropriate position relative to the biological tissue T.

[0023] Next, as shown in FIG. 4( a), the operating member 10 is pressed, causing the main body 5 to protrude from the tip of the sheath 2 and puncture the biological tissue T (step S1). At this time, the presence of the slit 6 allows the biological tissue T to penetrate deep into the main body 5. Next, as shown in FIG. 4( b), the operating member 10 is rotated, causing the main body 5 to rotate (step S2). The biological tissue T inside the main body 5 rotates together with the main body 5 due to friction between the biological tissue T inside the main body 5 and the inner circumferential surface 5d. As a result, the biological tissue T is cut at the slit 6 and torn by twisting at the distal opening 5c, separating the biological tissue T inside the main body 5 from the biological tissue T outside the main body 5. At this time, the biological tissue T is easily cut by the distal blade 7 and the slit blade 8.

[0024] 4(c), by pulling the operating member 10, the main body 5 is withdrawn from the biological tissue T and completely housed in the sheath 2 (step S3). Thereafter, by withdrawing the sheath 2 housing the main body 5 from the treatment instrument channel, the needle tube 3 is removed from the body. As a result, the biological tissue T taken into the main body 5 is collected.

[0025] In this case, according to the present embodiment, the slit 6 provided in the main body 5 allows a larger amount of biological tissue T to be taken into the main body 5 during puncture compared to a case in which the slit 6 is not provided. This increases the amount of biological tissue T that can be collected. Furthermore, according to the present embodiment, the length L is 3 mm or more and 25 mm or less, and the opening angle θ is 30° or more and 90° or less, thereby further increasing the amount of biological tissue T that can be collected, and ensuring that a sufficient amount of biological tissue T can be collected.

[0026] 5(a) and 5(b) illustrate the difference in the amount of collected biological tissue T depending on the length L, with Fig. 5(a) showing the case where the length L is short and Fig. 5(b) showing the case where the length L is long. During puncturing, the longer the length L, the deeper the biological tissue T penetrates into the main body 5, and more biological tissue T is taken into the main body 5. On the other hand, the longer the length L, the greater the contact area, i.e., the greater the friction, between the biological tissue T inside the main body 5 and the biological tissue T outside the main body 5. Therefore, the longer the length L, the easier it is for the biological tissue T to pass through the distal end opening 5c ​​and come out of the main body 5 during removal.

[0027] When the length L is 3 mm or more and 25 mm or less, it is possible to simultaneously take in a sufficient amount of biological tissue T into the main body 5 when puncturing and prevent the biological tissue T from falling out when removing the probe. This makes it possible to obtain a sufficient amount of collected biological tissue T even if the biological tissue T contains a lot of water and is slippery relative to the main body 5. When the length L is shorter than 3 mm or longer than 25 mm, it is difficult to take in a sufficient amount of biological tissue T into the main body 5 when puncturing the probe, or the biological tissue T falls out of the main body 5 when removing the probe, making it difficult to obtain a sufficient amount of collected biological tissue.

[0028] 6(a) and 6(b) illustrate the difference in the amount of biological tissue T collected depending on the opening angle θ, with FIG. 6(a) showing the case where the opening angle θ is small and FIG. 6(b) showing the case where the opening angle θ is large. During puncture, the larger the opening angle θ, the easier it is for the biological tissue T to enter the main body 5, and more biological tissue T is taken into the main body 5. On the other hand, during rotation, the larger the opening angle θ, the easier it is for the biological tissue T to pass through the slit 6 and escape from the main body 5 (see the right diagram of step S2). Furthermore, the larger the opening angle θ, the greater the contact area, i.e., the greater the friction, between the biological tissue T inside the main body 5 and the biological tissue T outside the main body 5. Therefore, the larger the opening angle θ, the easier it is for the biological tissue T to escape from the main body 5 through the distal opening 5c ​​during removal.

[0029] When the opening angle θ is 30° or more and 90° or less, it is possible to both take in a sufficient amount of biological tissue T into the main body 5 during puncturing and prevent the biological tissue T from slipping out during rotation and removal. This makes it possible to obtain a sufficient amount of collected biological tissue T even if the biological tissue T contains a lot of water and is slippery against the main body 5. When the opening angle θ is less than 30° or greater than 90°, it is difficult to take in a sufficient amount of biological tissue T into the main body 5 during puncturing, or the biological tissue T slips out during rotation and removal, making it difficult to obtain a sufficient amount of collected biological tissue.

[0030] 7 shows the results of an experiment in which the amount of biological tissue T collected was measured using needle tubes 3 (#1 to #8) having various lengths L and opening angles θ. The diameter of the main body 5 used in the experiment was 19G (inner diameter approximately 0.7 mm), and the biological tissue T was collected by puncturing, rotating, and removing the main body 5. The amount of collected biological tissue T was evaluated on a three-level scale: "A (excellent)," "B (good)," and "C (fair)," depending on the weight of the collected biological tissue T. "A" indicates the largest amount collected, and "C" indicates the smallest amount collected.

[0031] As can be seen from Figure 7, biological tissue T was successfully collected using all of the needle tubes #1 to #8. The amount of collected tissue was large when the length L x opening angle θ was in the range of more than 300 and not more than 1500, and was particularly large when the length L x opening angle θ was in the range of 600 to 900. Therefore, the length L x opening angle θ is preferably in the range of more than 300 and not more than 1500, and more preferably in the range of 600 to 900.

[0032] In this embodiment, it is preferable that the slit 6 has a narrow portion 15 having a width narrower than other portions of the slit 6. The narrow portion 15 is provided at the base end of the slit 6. For example, as shown in Figures 8(a) and 8(b), the width of the slit 6 may be gradually reduced continuously from a midpoint in the longitudinal direction toward the base end, thereby forming the narrow portion 15 at the base end of the slit 6. The width may be reduced in stages toward the base end, or may be gradually reduced from the tip of the slit 6 to the base end.

[0033] 9(a) and 9(b) illustrate the difference in the amount of biological tissue T collected depending on whether or not the narrow portion 15 is present. FIG. 9(a) shows the case with the narrow portion 15, and FIG. 9(b) shows the case without the narrow portion 15. The smaller the width of the slit 6, the greater the contact area, i.e., friction, between the biological tissue T in the main body 5 and the inner circumferential surface 5d. Therefore, the narrow portion 15 increases the holding force of the main body 5 against the biological tissue T in the main body 5, providing an anchor effect that more firmly holds the biological tissue T within the main body 5. Furthermore, the presence of the narrow portion 15 reduces the contact area between the biological tissue T in the main body 5 and the biological tissue T outside the main body 5, thereby preventing the biological tissue T from slipping out of the main body 5 during removal. This more reliably prevents the biological tissue T from slipping out of the main body 5 during removal, further improving the amount of biological tissue T collected.

[0034] In this embodiment, it is preferable that the cutting edge 8a of the slit blade 8 is located at the radially outer end of the side surface 6c. Figures 10(a) and 10(b) show cross sections of the main body 5 perpendicular to the longitudinal axis A. In Figure 10(a), the cutting edge 8a is located at the radially outer end of the side surface 6c, i.e., on the outer peripheral surface 5e. In Figure 10(b), the cutting edge 8a is located at the radially inner end of the side surface 6c, i.e., on the inner peripheral surface 5d.

[0035] When the cutting edge 8a is located at the radially outer end, the biological tissue T inside the main body 5 is less likely to pass through the slit 6 and exit when the main body 5 is rotated (see FIG. 10(a)). On the other hand, when the cutting edge 8a is located at the radially inner end, the biological tissue T inside the main body 5 is more likely to pass through the slit 6 and exit when the main body 5 is rotated (see FIG. 10(b)). Therefore, by positioning the cutting edge 8a at the radially outer end, the amount of biological tissue T that can be collected can be further improved.

[0036] In this embodiment, as shown in Fig. 11(a), the position of the cutting edge 8a may change from the radially outer end of the side surface 6c to the radially outer end at a midpoint in the longitudinal direction of the slit blade 8. In Fig. 11(a), the position of the cutting edge 8a is the radially outer end at the base end side and the radially inner end at the tip end side. Similarly, as shown in Fig. 11(b), the position of the cutting edge 7a may change from the radially inner end of the tip surface 5a to the radially outer end at a midpoint in the longitudinal direction of the tip blade 7. In Fig. 11(b), the position of the cutting edge 7a is the radially outer end at the base end side and the radially inner end at the tip end side.

[0037] In this embodiment, the slit 6 is positioned 180° offset from the needle tip 5b, but the position of the slit 6 is not limited to this and may be other positions. Specifically, when viewed from the distal end along the longitudinal axis A, the slit 6 can be positioned in any range that does not overlap with the needle tip 5b. As long as the slit 6 is positioned in this range, the above-described effects can be achieved. Figure 12 schematically shows an example of the positional relationship between the needle tip 5b and the slit 6 when viewed from the distal end along the longitudinal axis A. For example, the slit 6 may be positioned in the range indicated by θ1 or θ2. Preferably, the slit 6 is positioned where a straight line B passing through the needle tip 5b and the longitudinal axis A passes through the slit 6 (e.g., the position indicated by θ2). The range indicated by θ3, which includes the needle tip 5b, is unsuitable for forming the slit 6.

[0038] Although the embodiments and modifications of the present invention have been described above in detail with reference to the drawings, the specific configuration of the present invention is not limited to the above-described embodiments and modifications, and various design modifications are possible within the scope of the gist of the present invention. Furthermore, the components shown in the above-described embodiments and modifications can be combined as appropriate. For example, the needle tube and biopsy device of the present invention may be applied to any biopsy method other than EUS-FNA / FNB, and may be rigid.

[0039] REFERENCE SIGNS LIST 1 Biopsy device 2 Sheath 3 Needle tube 5 Main body 5a Distal end surface 5b Distance 5c Distance opening 5d Inner peripheral surface 5e Outer peripheral surface 6 Slits 6a, 6b Side ends 6c Side surface 7 Distance blade 7a Cutting edge 8 Slit blade 8a Cutting edge 15 Narrowed portion A Longitudinal axis L Length θ Opening angle T Biological tissue

Claims

1. A needle tube comprising a tubular body, the body having a slit extending in the longitudinal direction of the body from a tip opening towards a base end of the body and radially penetrating a side wall of the body, the length from the tip of the body to the base end of the slit being 3 mm or more and 25 mm or less, and in a cross section perpendicular to the longitudinal axis of the body, the opening angle formed by two line segments connecting the center of the body to both side ends in the width direction of the slit is 30° or more and 90° or less.

2. The needle tube of claim 1, wherein said slit has a narrowed portion at its proximal end, said narrowed portion having a width narrower than the remainder of said slit.

3. The needle tube according to claim 1, wherein the body has a slit blade consisting of an outer circumferential surface of the body and a side surface of the slit which forms an acute angle with the outer circumferential surface, and the cutting edge of the slit blade is located at the radially outer end of the side surface.

4. The needle tube according to claim 1, wherein the product of said length and said opening angle is within a predetermined range.

5. A needle tube as claimed in claim 1, wherein said body has a slit blade consisting of an outer or inner peripheral surface of said body and a side surface of said slit which forms an acute angle with said outer or inner peripheral surface, and the position of the tip of said slit blade changes from the radially outer end of said side surface to the radially inner end at a midpoint in the longitudinal direction.

6. A needle tube as claimed in claim 1, wherein said body has a tip blade consisting of an outer or inner peripheral surface of said body and a tip surface of said body which forms an acute angle with said outer or inner peripheral surface, and the position of the tip of said tip blade changes from the radially outer end of said tip surface to the radially inner end at a midpoint in the longitudinal direction.

7. The needle tube according to claim 1, wherein the main body has a sharp needle tip at its tip, and the slit is provided at a position that does not overlap with the needle tip when the main body is viewed in a direction along the longitudinal axis.

8. A needle tube as described in claim 7, wherein the slit is provided at a position where a straight line passing through the needle tip and the longitudinal axis passes through the slit when the main body is viewed in a direction along the longitudinal axis.

9. A biopsy device comprising: a sheath; a needle tube according to claim 1 that is provided within the sheath and capable of protruding from the tip of the sheath; and an operating section that is provided on the base end side of the sheath and that operates the sheath and the needle tube.

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