Puncture needle for perforation

Abstract

To provide a novel puncture needle for perforation capable of advantageously obtaining a treatment space within the right atrium while satisfactorily ensuring good transmission of hand manipulation force to the tip.　The puncture needle for perforation has a two-stage bent shape in which the tip side inserted into an atrium connects a proximal side bent section and a distal side bent section by a straight section, has a "bending angle θp of the proximal side bent section">"bending angle θd of the distal side bent section", and has a separation distance L of the needle tip with respect to an extension line of the straight section extending from the proximal side bent section toward the proximal side of 40 mm≥L≥70 mm.

Description

puncture needle for perforation

[0001] The present invention relates to a perforation needle for forming a patent hole in body tissue, and more particularly to a perforation needle that is inserted into the heart and is preferably used in a perforation procedure for forming a patent hole in the atrial septal wall (fossa ovalis).

[0002] A conventional treatment for atrial fibrillation involves cauterizing an appropriate region of the left atrium with an ablation catheter. Because it is difficult to insert an ablation catheter directly into the left atrium from the aortic vein, the ablation catheter is often inserted into the right atrium via the inferior vena cava and then through the atrial septum before being inserted into the left atrium. In this case, a patent hole penetrating the atrial septum must be formed beforehand to allow the ablation catheter to penetrate the atrial septum.

[0003] A known method for forming a patent hole in the atrial septum is the Brockenbrough method, which uses a sharp-tipped needle or a needle with a head that is activated by externally supplied radiofrequency energy.

[0004] As shown in the schematic diagram of Figure 4, the atrial septum wall 4 inside the heart 2 widens at an angle relative to the inferior vena cava 7 into which the puncture needle 6 is inserted. To efficiently puncture the atrial septum wall 4, it is necessary to press the tip of the puncture needle 6 approximately perpendicularly against the atrial septum 4. For this reason, in the conventional puncture needle 6, as shown in Figure 4, the distal end side that is inserted into the right atrium 8 has a curved shape that extends with an approximately constant radius of curvature so as to describe a smooth arc.

[0005] U.S. Patent No. 7,635,353

[0006] However, when the inventors examined the conventional puncture needle 6 having such a smooth arc-shaped curve at the distal end, they found that it had inherent problems that needed to be improved during the procedure.

[0007] Specifically, during the procedure, there are cases where another catheter, such as an intracardiac catheter echo (ICE), is inserted into the right atrium 8 and operated, but with the conventional arc-shaped puncture needle 6 for perforation, it starts out in a straight line in the extension direction of the inferior vena cava 7 within the right atrium 8, then gradually changes direction, making a large turn before reaching the atrial septal wall 4. For this reason, within the right atrium 8, the area to be treated, particularly in the extension direction of the inferior vena cava 7, is located on the path of the puncture needle 6, making it difficult to ensure space for other procedures, such as the insertion and operation of the ICE.

[0008] Furthermore, the reaction force of the tip of the perforation needle 6 pressing against the atrial septum 4 acts in a dispersed manner over the entire curved distal end of the perforation needle 6, making the distal end prone to bending significantly over the entire length. As a result, the inclination angle of the tip pressing against the atrial septum 4 is prone to change unstably, which may hinder stable perforation operations.

[0009] The problem to be solved by the present invention is to provide a novel puncture needle that can reduce or eliminate at least one of the above-mentioned problems that the inventors have newly discovered in the conventional puncture needle structure shown in Figure 4.

[0010] The following describes preferred embodiments for understanding the present invention, but the embodiments described below are merely examples and may be appropriately combined with one another. Multiple components described in each embodiment may be recognized and employed independently to the greatest extent possible, and may also be appropriately combined with any of the components described in other embodiments. Accordingly, the present invention is not limited to the embodiments described below, and various other embodiments may be realized.

[0011] The first aspect is as follows: A puncture needle for perforating the atrial septum wall, the tip side of which is inserted into the atrium has a two-stage bent shape in which a proximal bent portion and a distal bent portion are connected by a straight portion, and the bending angle θp of the proximal bent portion and the bending angle θd of the distal bent portion satisfy θp > θd.

[0012] The puncture needle for perforation according to this embodiment differs from the conventional structure that is curved over its entire length as shown in Fig. 4 in that it has a two-stage bent shape and the proximal bent portion is bent at a larger angle than the distal bent portion, and therefore, unlike the conventional structure (see Fig. 4) that extends linearly in the extension direction of the inferior vena cava 7 within the right atrium 8, it can be bent relatively greatly toward the atrial septum near the connection portion of the inferior vena cava to the right atrium. This makes it possible to reduce the area substantially occupied within the right atrium by the puncture needle for perforation inserted into the right atrium, and makes it easy to secure a large space in the extension direction of the inferior vena cava that is required for other procedures within the right atrium.

[0013] A second aspect is as follows: The puncture needle for puncturing according to the first aspect, wherein a radius of curvature Rp of the proximal bent portion and a radius of curvature Rd of the distal bent portion satisfy Rp≧Rd, and an arc length lp of the proximal bent portion and an arc length ld of the distal bent portion satisfy lp≧ld.

[0014] With the perforation puncture needle according to this embodiment, when inserted into the right atrium, the proximal bent portion and the straight portion extending proximally from there can be more stably supported by body tissue. That is, a bending moment acts on the proximal bent portion and the straight portion extending proximally from there due to the reaction force (axial force) acting on the needle tip when perforating the atrial septal wall, but by setting the radius of curvature Rp of the proximal bent portion to a relatively large value, these portions can be more stably supported by the wall of the right atrium and the wall of the inferior vena cava, and excessive deformation of these portions can also be suppressed.

[0015] A third aspect is as follows: The puncture needle for puncturing according to the first or second aspect, wherein the proximal curved portion and the distal curved portion have the same structure over their respective entire lengths.

[0016] In the puncture needle for perforation according to this embodiment, the proximal bending portion and the distal bending portion have the same structure and have approximately equal deformation rigidity, which makes it possible to suppress the concentration of deformation on one side, such as the proximal bending portion, thereby improving the overall shape stability.

[0017] A fourth aspect is as follows: The puncture needle for puncturing according to any one of the first to third aspects, wherein a distance L between the needle tip and an extension line of the straight portion extending from the proximal bent portion toward the proximal side is 20 mm≧L≧80 mm.

[0018] In the puncture needle for perforation according to this embodiment, by ensuring the relative relationship (θp>θd) between the bending angle θp of the proximal bending portion and the bending angle θd of the distal bending portion as described above, and then setting a specific separation distance L, it becomes easy to properly guide the puncture needle to the perforation site in the atrial septal wall while more efficiently securing space in the extension direction of the inferior vena cava that is required for other procedures within the right atrium.

[0019] The perforation needle of the present invention, when inserted into the right atrium, can secure a larger space, particularly in the direction of extension of the inferior vena cava, compared to conventional arc-shaped curved perforation needles. Therefore, even when the perforation needle is inserted into the right atrium, space for other procedures can be secured in the right atrium, making the procedure easier.

[0020] 1 is an explanatory diagram showing an enlarged view of the tip end of the puncture needle for perforation according to an embodiment of the present invention; FIG. 2 is an explanatory diagram for explaining the function and effect of the tip end of the puncture needle for perforation shown in FIG. 2; and FIG. 3 is an explanatory diagram showing a specific example of a puncture needle for perforation having a conventional structure.

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] 1 to 3 show a puncture needle 10 as a first embodiment of the present invention. In the following description, the base end that faces the practitioner when in use will be referred to as the proximal end, and the tip end that faces the patient will be referred to as the distal end. The present invention can also be applied to a puncture needle that has a sharp, cutting-edge-shaped needle tip and punctures body tissue by the pushing force of the needle tip. However, this embodiment shows an example in which the present invention is applied to a puncture needle that has a drilling head at its tip that is actuated by energy such as a high-frequency current supplied from an external source.

[0023] The puncture needle 10 of this embodiment has a main body 12 made of a longitudinal tube structure, with a drilling head 14 provided at the distal end of the main body 12 and a handpiece 16 for operation by the practitioner fixedly attached to the proximal end of the main body 12. A drilling operation unit 18 that controls the supply of high-frequency current to the drilling head 14 is connected to the handpiece 16, and a luer connector 20 is provided to enable a liquid such as a contrast agent to be supplied from the outside through the main body 12, as necessary. The configuration of the operation unit including the handpiece 16 and the like is optional and can be changed as appropriate depending on the function, etc., of the puncture needle 10.

[0024] Here, the main body portion 12 of the puncture needle 10 for puncturing may be a single tube member that is continuous in the length direction, or may be configured by connecting a plurality of tube members in the length direction.

[0025] Specifically, in this embodiment, the distal end side that penetrates the atrial septum and is inserted into the left atrium is a small-diameter tip tube 24 over a predetermined length. The base end side of the tip tube 24 is fixedly connected by welding, fitting, or the like to the tip portion of a main tube 26 that extends from the proximal end side toward the distal end side, thereby forming the main body portion 12 with a structure in which the tip tube 24 is connected to the main tube 26.

[0026] A drilling head 14 is attached to the tip of a distal tube 24 that constitutes the main body portion 12. The drilling head 14 of this embodiment forms a patent hole in body tissue by external energy supply such as high-frequency current, and forms a patent hole in body tissue by cauterizing the body tissue, etc.

[0027] Although the shape of the drilling head 14 is not limited to a specific one, it is desirable that the distal surface be a curved surface without corners so as to prevent snagging when moving through a lumen, for example, a generally hemispherical shape that is convex toward the distal end. The drilling head 14 has, for example, fitting legs that protrude toward the proximal end, and the fitting legs are inserted into the opening on the distal end side of the tip tube 24 and fixed by fitting, welding, or the like, thereby attaching so as to close the opening of the tip tube 24. Note that the distal portions of the drilling head 14 and the tip tube 24 may be appropriately provided with through-holes that penetrate, for example, the peripheral walls, to enable injection of contrast medium, heparin, etc. through the inner holes (lumens) of the drilling head 14 and the tip tube 24.

[0028] Furthermore, the main body portion 12, which is made of a tube structure, has a continuous lumen from the proximal end to the distal end, and through this lumen it is possible, for example, to detect the pressure within the atrium into which the distal end is inserted, or to supply or discharge a liquid. In this embodiment, the tip tube 24 and the main body tube 26 are both cylindrical tubes that have a substantially constant hollow cross section and extend in the longitudinal direction, and this can form the main body portion 12 with one lumen, but a structure with multiple lumens may also be used.

[0029] The tip tube 24 and main tube 26 that make up the main body portion 12 are flexible and can deform to follow the curvature of a body lumen such as a blood vessel. The material of the tip tube 24 and main tube 26 is not particularly limited and may be metal, synthetic resin, fiber-reinforced resin, carbon fiber reinforced thermosetting plastic (CFRP), etc., but is preferably made of metal in consideration of electrical conductivity, etc.

[0030] That is, power supply to the drilling head 14 can be achieved by providing dedicated wiring using the lumen, but for example, the conductive main body portion 12 can also be used as the current-carrying wiring, which can simplify the structure and reduce the number of parts. In this case, providing an insulating layer made of an electrically insulating material on the outer surfaces of the tip tube 24 and the main tube 26 can prevent unintended cauterization of body tissue and reduce frictional resistance with the sheath, dilator, etc. used during the procedure. There are no particular restrictions on the material of such an insulating layer, but fluorine-based resin is preferably used, and the insulating layer can be formed by coating or by using heat-shrink tubing.

[0031] Here, the main body portion 12 (main body tube 26 in this embodiment) has bent portions that are bent into a predetermined shape at midpoints along its length. That is, the main body tube 26 has a straight portion 30 at its proximal end that extends linearly from the handpiece 16, and two bent portions at the distal end of the straight portion 30 that are inserted into the atrium during treatment.

[0032] Specifically, a two-stage bent portion is provided on the distal side of the straight portion 30, in which two bent portions, a proximal bent portion 32 and a distal bent portion 34, are connected by an intermediate straight portion 36 that is a linear portion that is provided between them and extends linearly. As a result, the main body portion 12 is composed of the straight portion 30 that extends linearly from the proximal end side, the proximal bent portion 32 that is the first bent portion, the linearly extending intermediate straight portion 36, the distal bent portion 34 that is the second bent portion, and the distal straight portion 40 that extends linearly all the way to the drilling head 14.

[0033] In short, as shown in the model of Figure 3, the main body portion 12 consisting of a tube structure of the puncture needle 10 for puncturing of this embodiment has a straight portion 30 and an intermediate straight portion 36 connected by a proximal bent portion 32 at a predetermined bending angle θp, and furthermore, the intermediate straight portion 36 and the tip straight portion 40 connected by a distal bent portion 34 at a predetermined bending angle θd.

[0034] In this embodiment, the entire length of the section from the straight section 30 to the tip of the distal curved section 34 is formed as a single piece of the main tube 26, and even if the base end of the tip tube 24 is inserted into the main tube 26 at the connection section to the main tube 26, it does not reach at least the distal curved section 34. As a result, the proximal curved section 32 and the distal curved section 34 are constructed of the same tube structure over their respective entire lengths, and have the same basic characteristics such as strength.

[0035] The bending angle θp at the proximal bending portion 32 is larger than the bending angle θd at the distal bending portion 34, such that θp > θd. Note that the bending angle refers to the bending angle formed by the center lines of two linear portions or straight sections located on either side of each bending portion, as shown in Figure 3. Preferably, the bending angle θp at the proximal bending portion 32 is set within a range of 23 to 53 degrees, and the bending angle θd at the distal bending portion 34 is set within a range of 7 to 37 degrees.

[0036] Furthermore, taking into consideration the subject of the procedure, when the perforation head 14 is inserted from the inferior vena cava 7 into the right atrium 8 to perforate the atrial septal wall 4 as shown in FIG. 4 , it is desirable that the proximal curved portion 32 be positioned near the opening of the inferior vena cava 7 to the right atrium 8 and that the distal straight portion 40 be directed approximately perpendicular to the atrial septal wall 4 so that the perforation head 14 reaches the intended perforation site in the atrial septal wall 4.

[0037] Therefore, as shown in Figure 3, the distance L between the extension line of the straight portion 30 and the tip of the needle (the tip of the perforation head 14) is preferably set to 20 mm ≥ L ≥ 80 mm, taking into account the physique and age of the patient to be treated, and more preferably set to 45 mm ≥ L ≥ 70 mm.

[0038] Furthermore, considering that, based on anatomical information and the like, the relative inclination angle (α in FIG. 2 ) between the direction of the opening of the inferior vena cava 7 into the right atrium and the direction of the widening of the atrial septum is generally approximately 20 degrees, the relative inclination angle of the distal straight portion 40 with respect to the straight portion 30 is preferably approximately 70 degrees, for example, within the range of 60 to 80 degrees, so that the distal straight portion 40 is oriented approximately perpendicular to the atrial septum. In other words, the sum θp+θd of the bending angle θp of the proximal bending portion 32 and the bending angle θd of the distal bending portion 34 is preferably 60 degrees≦(θp+θd)≦80 degrees.

[0039] Furthermore, both the proximal bent portion 32 and the distal bent portion 34 have a smoothly curved shape with no bending points along their entire length, but it is also desirable that each end be smoothly connected to the straight portion 30, the linear portion 36, and the distal linear portion 40 via a common tangent.

[0040] In this embodiment, both the proximal bending portion 32 and the distal bending portion 34 have a curved arc shape with a constant radius of curvature over their entire length. Here, the radius of curvature Rp of the proximal bending portion 32 is set to be greater than or equal to the radius of curvature Rd of the distal bending portion, so that Rp≧Rd is satisfied. It is not necessary for the radii of curvature of the proximal bending portion 32 and the distal bending portion 34 to be constant over their entire length. However, if the radii of curvature change partially or gradually in the length direction, it is sufficient that Rp≧Rd be satisfied, with the weighted average value weighted by length being the radius of curvature.

[0041] Furthermore, the length of each of the straight portion 30, the proximal bent portion 32, the linear portion 36, the distal bent portion 34, and the tip linear portion 40 is not particularly limited, and for example, the length of the straight portion 30 is generally set taking into consideration the length of the inferior vena cava 7 from the insertion position into the body from the lower leg, but can also be set to an appropriate length taking into consideration the preference of the practitioner, etc. Furthermore, for example, when the magnitude relationship between the bending angles θp and θd is taken into consideration, it is desirable that the length (arc length) lp of the proximal bent portion 32 be equal to or greater than the length (arc length) ld of the distal bent portion 34, i.e., lp≧ld.

[0042] 3 , the dimension Lp between the bending point Pp of the proximal bending portion 32 (the intersection of the extensions of the straight portion 30 and the linear portion 36) and the bending point Pd of the distal bending portion 34 (the intersection of the extensions of the linear portion 36 and the distal linear portion 40) is preferably set within the range of 0.2≦Ld / Lp<2.0, more preferably 0.5≦Ld / Lp<1.5, relative to the dimension Ld from the bending point Pd of the distal bending portion 34 to the drilling head 14. If Ld / Lp is too small, the bending moment acting on the linear portion 36, the proximal bending portion 32, etc. due to the pressing reaction force F of the drilling head 14 against the atrial septum, as described below, will increase, raising concerns about an increase in the amount of deformation of the main body portion 12. On the other hand, if Ld / Lp is too large, there is a risk of adversely affecting the securing of a treatment space when inserted into the right atrium, as described below.

[0043] When performing the procedure (Brockenbrough method) for forming a patent foramen in the atrial septum wall using the perforation needle 10 constructed as described above, the distal end of the perforation needle 10 is inserted into the patient's body, for example, from the lower leg, and guided into the right atrium via the inferior vena cava. At this time, the distal end of the perforation needle 10 is guided into the right atrium by inserting it through a sheath or dilator that has been inserted in advance from the inferior vena cava 7 toward the right atrium using, for example, a guide wire.

[0044] Then, the drilling head 14 is inserted into the right atrium and protrudes from the distal end of the sheath, and pressed against the intended drilling site in the atrial septal wall. High-frequency current is then supplied from the outside, drilling the atrial septal wall and forming a patent hole.

[0045] During such a procedure, even when the distal end of the main body 12 is inserted into the right atrium, as can be seen from the schematic diagram of Figure 3, the proximal bending portion 32 has a larger bending angle than the distal bending portion 34, so that the entire main body 12 extending from the inferior vena cava 7 into the right atrium can be positioned closer to the atrial septum than in the conventional structure shown in Figure 4. As a result, a large treatment space can be secured in the right atrium in the extension direction of the inferior vena cava 7. This allows for improved operability when performing a procedure in the right atrium using, for example, another catheter inserted through the inferior vena cava 7 (specifically, the aforementioned procedure using ICE).

[0046] Furthermore, by making the bending angle θp of the proximal bending portion 32 larger than the bending angle θd of the distal bending portion 34, it is possible to suppress the bending moment and, in turn, deformation that is applied to the straight portion 36 by the pressing reaction force F of the perforation head 14 against the atrial septum. That is, as shown in Fig. 3, the pressing reaction force F applied to the straight portion 36 generates components of an axial force N and a shear force Q, and the shear force Q that applies a bending moment to the straight portion 36 is expressed by the following equation: Q = F sin θd In short, the bending moment in the straight portion 36, i.e., the amount of deformation, can be suppressed by reducing the bending angle θd of the distal bending portion 34. Here, the sum θp + θd of the bending angle θp of the proximal bending portion 32 and the bending angle θd of the distal bending portion 34 is set to a predetermined value as described above, so the bending angle θd of the distal bending portion 34 can be reduced by setting the bending angle θp of the proximal bending portion 32 to a large value.

[0047] In the perforation puncture needle 10 described above, since θp > θd, it is possible to suppress the amount of deformation of the linear portion 36 due to the pressing reaction force F of the perforation head 14, and the perforation head 14 can be more stably pressed against the atrial septum to perform the perforation operation. Moreover, the pressing force exerted from the outside on the perforation head 14 via the main body 12 during the perforation operation is also suppressed from escaping due to elastic deformation of the main body 12, so that the pressing force can be applied to the perforation head 14 efficiently and with good directionality during the perforation operation.

[0048] 3, the deformation of the main body 12 caused by the pressing reaction force F of the perforation head 14 against the atrial septum mainly includes bending deformation of the straight portion 36, as well as a change in the bending angle at the bending point Pp of the proximal bent portion 32 and bending deformation of the straight portion 30 extending proximally from the proximal bent portion 32. Here, the relative positional relationship between the perforation head 14 and the proximal bent portion 32 and the extending direction of the distal straight portion 40 are set to predetermined values ​​based on the relationship between the position of the inferior vena cava 7 in the heart and the position of perforation of the atrial septum. Therefore, even if the bending angle θp of the proximal bending portion 32 and the bending angle θd of the distal bending portion 34 are changed relative to each other, the magnitude and direction of the pressing reaction force F, and therefore the moment arm length with respect to the bending point Pp and the straight portion 30, remain constant and do not change, so there is no change in the bending angle at the bending point Pp of the proximal bending portion 32 or large bending deformation in the straight portion 30 extending from the proximal bending portion 32 to the proximal side.

[0049] On the other hand, the radius of curvature Rp of the proximal bending portion 32 is set relative to the radius of curvature Rd of the distal bending portion 34 such that Rp≧Rd, and in this embodiment, the length dimension (arc length) lp of the proximal bending portion 32 is set relative to the length dimension (arc length) ld of the distal bending portion 34 such that lp≧ld. This allows the proximal bending portion 32 to have a gentle curve and a large arc length. As a result, even if the main body portion 12 is deformed by, for example, the pressing reaction force F of the drilling head 14 against the atrial septum, a length region that can be supported by abutting against the vascular wall near the connection of the inferior vena cava to the right atrium and the wall of the right atrium is likely to be secured in a relatively long region from the straight portion 30 to the proximal bending portion 32, and the main body portion 12 can be supported with good positional stability.

[0050] Furthermore, in this embodiment, the proximal bending portion 32 and the distal bending portion 34 are constructed of the same tube structure over their respective entire lengths, which makes it possible to suppress the concentration of deformation in one bending portion, such as the proximal bending portion 32, thereby improving the overall shape stability.

[0051] That is, for example, it is conceivable to insert and fix the proximal end portion of the tip tube 24 from the distal end of the main tube 26 and extend the tip tube 24 to the distal bent portion 34 formed by the main tube 26, thereby forming the distal bent portion 34 as a double-tube structure. However, this would result in the rigidity of the distal bent portion 34 being excessively greater than that of the proximal bent portion 32, which is a single-tube structure of the main tube 26, resulting in a relative decrease in the rigidity of the proximal bent portion 32. In the first place, the proximal bent portion 32 has a greater acting arm length and therefore a greater acting bending moment due to the pressing reaction force of the drilling head 14 against the atrial septum during drilling than the distal bent portion 34, which raises concerns about a greater risk of deformation of the proximal bent portion. In this embodiment, the proximal bent portion 32 and the distal bent portion 34 have the same structure and substantially equal deformation rigidity, thereby suppressing deformation concentration at the proximal bent portion 32 and improving the overall shape stability of the main body portion 12.

[0052] In addition, when manufacturing the main body 12 using a straight tubular material such as an extrusion molded product, if the proximal bent portion 32 or the distal bent portion 34 is bent by plastic deformation, there is a risk that the cross-sectional shape will change from a perfect circle to an ellipse as a result of the bending deformation, and there is a concern that such a change in cross-sectional shape will reduce bending rigidity or bending strength. In this aspect, the proximal bent portion 32 has a larger acting arm length of the pressing reaction force of the drilling head 14 against the atrial septum wall during drilling, and therefore a larger acting bending moment, than the distal bent portion 34. Therefore, the radius of curvature Rp of the proximal bent portion 32 satisfies Rp≧Rd with respect to the radius of curvature Rd of the distal bent portion 34. Therefore, the risk of a change in cross-sectional shape and therefore a reduction in bending rigidity, etc., due to bending can be reduced compared to the distal bent portion 34.

[0053] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the specific descriptions. For example, as shown in Figure 2, the linear length M from the straight portion 30 to the drilling head 14 at the distal end is set appropriately taking into account the patient's physique and other factors, and is not limited thereto, but is preferably set within the range of 600 to 900 mm.

[0054] Furthermore, the drilling head 14 need only emit energy for drilling, and is not necessarily limited to high-frequency energy. For example, the drilling head can be configured with a heating element (thermal energy) that cauterizes body tissue by heating with electricity or a laser, or a combination of multiple energies can be used. In addition to a mode in which energy is supplied from outside the device, the device may also be provided with a means for storing energy internally.

[0055] 2 Heart 4 Atrial septum (fossa ovalis) 6 Perforation needle 7 Inferior vena cava 8 Right atrium 10 Perforation needle 12 Main body portion (tube structure) 14 Perforation head 16 Handpiece 18 Perforation operation portion 20 Luer connector 24 Tip tube 26 Main body tube 30 Straight portion 32 Proximal bent portion 34 Distal bent portion 36 Straight portion 40 Tip straight portion

Claims

1. A puncture needle for perforating the atrial septum, wherein the tip side inserted into the atrium has a two-stage bending shape in which a proximal bending portion and a distal bending portion are connected by a straight portion, and a puncture needle in which the bending angle θp of the proximal bending portion and the bending angle θd of the distal bending portion satisfy θp > θd.

2. The puncture needle according to claim 1, wherein the radius of curvature Rp of the proximal bending portion and the radius of curvature Rd of the distal bending portion satisfy Rp ≥ Rd, and the arc length lp of the proximal bending portion and the arc length ld of the distal bending portion satisfy lp ≥ ld.

3. The puncture needle according to claim 1 or 2, wherein the proximal bending portion and the distal bending portion have the same structure as each other over their entire lengths.

4. The puncture needle according to claim 1 or 2, wherein the separation distance L of the needle tip from the extension line of the straight portion extending proximally from the proximal bending portion satisfies 20 mm ≥ L ≥ 80 mm.

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