JP2005102860A - Catheter assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter assembly preventing deflection of a bending direction of a tip part, even if detaching a stylet connector from a catheter connector, and facilitating the attaching/detaching operation between the catheter connector and the stylet connector. <P>SOLUTION: This catheter assembly 1 is provided with a fitting state regulating means 15 formed so that the catheter connector 3 is fitted with the stylet connector 5 only when the bending direction of a catheter angle part formed in the tip of a catheter body 2 and a bending direction of a stylet angle part formed in the tip of a stylet body 4 are almost aligned with each other; and regulating their relatively rotatable angle within a range of 5-40° in a state where the catheter connector 3 is fitted with the stylet connector 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a catheter assembly used when, for example, infusion is performed on a living body.

  2. Description of the Related Art A catheter assembly is known that includes a linear stylet made of a metal material or the like that is detachably inserted into a hollow portion of a catheter. This stylet has a function of imparting rigidity to the catheter in order to facilitate insertion of the catheter into the living body. As an example of such a catheter assembly, a central venous catheter placed in the superior vena cava when performing high-calorie infusion therapy will be described.

  FIG. 14 shows a schematic view of a blood vessel in the vicinity of the superior vena cava (central vein) when the patient is facing the front. In such a catheter placement method, a split cannula having an inner needle is generally used as a clavicle. Puncture is performed by the inferior venipuncture method, and after the needle tip reaches the blood vessel, the inner needle is removed, and the distal end of the catheter is placed in the optimal placement area indicated by the oblique line in the superior vena cava via the cannula.

  When a doctor secures a blood vessel, the approach from the internal jugular vein poses no problem, but especially in the case of subclavian vein puncture, depending on where the needle reaches the blood vessel, the internal jugular vein, the external jugular vein, or the puncture position Had the risk of entering the subclavian vein on the opposite side (mislodging of the catheter).

  That is, when the blood vessel arrival position of the needle tip is in the vicinity of a bifurcation such as the bifurcation point of the subclavian vein and the internal jugular vein, the catheter is highly likely to enter a blood vessel other than the superior vena cava. For example, as shown in FIG. 15, when a doctor punctures toward the right subclavian vein, the patient turns to the left in order to exaggerate the puncture site. The arrangement is more linear with the subclavian vein. In such a case, when the tip of the needle reaches the branch portion indicated by the arrow from the optimum puncture area, when inserting a straight catheter, the catheter is inserted from the tip of the split cannula (the side punctured into the blood vessel). At the stage of protruding, it tends to be inserted in the direction of the right internal jugular vein before going down the blood flow (upper vena cava direction). Once the tip of the catheter is invaded to a blood vessel that is thinner than the superior vena cava other than the superior vena cava, the tip of the catheter is likely to hit the blood vessel wall, stimulates the vascular endothelium, and is supplied with a hypertonic nutrient solution. There has been a problem that extravasation of fluids occurs, such as spilling out of blood vessels.

  In order to solve the problem of invasion of blood vessels other than the superior vena cava, Japanese Patent Application Laid-Open No. 8-22412 (Patent Document 1) discloses a catheter assembly whose tip is curved in a predetermined direction.

  In the catheter assembly as disclosed in the publication, the distal end portion of the catheter and the distal end portion of the stylet are curved in the same manner, and in the state where these curved directions are aligned, By fitting and combining the installed connectors (hubs), the distal end portion (angle portion) of the catheter assembly is curved in a predetermined direction. Further, the stylet connector of the catheter assembly is provided with a mark 26 indicating the bending direction of the distal end portion (see FIG. 3 of the same publication).

  However, since the catheter connector and the stylet connector can be rotated relative to each other in the fitted state, combining the two in a state where the bending direction of the distal end portion of the catheter and the bending direction of the distal end portion of the stylet are not aligned. The bending direction of the tip of the solid body is out of order, and does not coincide with the mark indicating the bending direction. Usually, a doctor often performs an operation to confirm the movement by detaching the stylet connector from the catheter connector immediately before using the catheter assembly, and the rotation position of the catheter connector and the stylet connector is shifted by the operation. If it does, the bending direction of the tip may be out of order. Since the doctor performs the insertion operation while grasping the bending direction of the distal end portion with the mark, there is a problem that if the bending direction of the distal end portion is out of order, an appropriate procedure cannot be performed and it is difficult to insert the catheter into the target site.

Japanese Patent Laid-Open No. 8-22412

  An object of the present invention is to prevent a distal direction bending direction from being distorted even when an operation of detaching a stylet connector from a catheter connector is performed, and a catheter that can be easily attached to and detached from the catheter connector and the stylet connector. It is to provide an assembly.

Such an object is achieved by the present inventions (1) to (8) below.
(1) a catheter having a flexible catheter body having a hollow portion formed along the longitudinal direction thereof, and a catheter connector installed on the proximal end side of the catheter body;
A stylet body composed of a flexible linear body that can be inserted into the hollow portion of the catheter body, and is installed on the proximal end side of the stylet body and is detachable by fitting to the catheter connector. A catheter assembly comprising a stylet having a stylet connector,
The catheter body is formed near its tip, and has a curved catheter angle portion in a single state,
The stylet body has a stylet angle portion formed in the vicinity of the tip thereof and curved in a shape corresponding to the catheter angle portion in a single state,
The catheter connector and the stylet connector can be fitted only in a state where the bending direction of the catheter angle portion and the bending direction of the stylet angle portion are substantially aligned, and the catheter connector and the stylet connector A catheter assembly comprising a fitting state restricting means for restricting an angle at which the two members can rotate relative to each other in a state where they are fitted.

  (2) The fitting state restricting means restricts an angle in which the catheter connector and the stylet connector can be relatively rotated in a state where the catheter connector and the stylet connector are fitted to each other in a range of 5 to 40 °. Catheter assembly.

  (3) In the state where the stylet body is inserted into the hollow portion of the catheter body and the stylet connector is fitted to the catheter connector, the tip of the stylet body does not protrude from the tip of the catheter body. The catheter assembly according to (1) or (2).

  (4) The fitting state regulating means includes at least one projection provided on the stylet connector and a concave portion provided on the catheter connector into which the projection can be inserted. The catheter assembly according to any one of 3).

  (5) The catheter assembly according to (4), wherein the protrusion also has a function of indicating a bending direction of the stylet angle portion.

  (6) The fitting state restricting means is provided in the catheter connector, and is provided in the elliptical lumen having an elliptical cross section on the inner peripheral surface and the stylet connector, and the cross sectional shape on the outer peripheral surface is the The catheter assembly according to any one of (1) to (3), wherein the catheter assembly has an elliptical shape smaller than the elliptical lumen and is configured by an elliptical portion that can be inserted into the elliptical lumen.

  (7) The stylet connector includes a protrusion that indicates a bending direction of the bending portion of the stylet angle portion and has a function as a finger contact portion for rotating the stylet connector with respect to the catheter connector. (1) The catheter assembly according to any one of (6).

  (8) The catheter connector includes a protrusion that indicates a bending direction of the bending portion of the catheter angle portion and has a function as a finger contact portion for relatively rotating the stylet connector and the catheter connector. The catheter assembly according to any one of (1) to (7) above.

According to the catheter assembly of the present invention, since the angle at which the stylet connector and the catheter connector are fitted to each other is regulated within a predetermined range, the stylet connector and the catheter connector are Even in the case where an operation of re-fitting is performed after the detachment is performed, it is possible to reliably prevent the bending direction of the angle portion formed at the distal end portion of the catheter assembly from deviating. Therefore, the catheter assembly can be smoothly and accurately inserted into the target site without straying in the body cavity.
The angle at which the stylet connector and the catheter connector can be rotated relative to each other is such that the stylet connector and the catheter connector are twisted with each other to release or re-fit the two. Since a sufficient angle is secured for operation, when the stylet connector and the catheter connector are attached and detached, they can be easily attached and detached.

  Hereinafter, a catheter assembly of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

  1 is a side view showing an embodiment of the catheter assembly of the present invention, FIG. 2 is an enlarged side view showing the vicinity of the distal end of the catheter assembly shown in FIG. 1, and FIG. 3 is a catheter set shown in FIG. FIG. 4 is a side view showing a stylet in the catheter assembly shown in FIG. 1, and FIGS. 5 and 6 are a stylet connector and a catheter connector in the catheter assembly shown in FIG. 1, respectively. FIG. 7 is a cross-sectional view taken along line XX in FIG. 6, and FIG. 8 and FIG. 9 are views of inserting the catheter assembly shown in FIG. 1 into the superior vena cava, respectively. FIG. 10 is a diagram schematically illustrating the state, and FIG. 10 is a diagram illustrating a blood vessel model used in the insertion operability test. In the following, for convenience of explanation, the right side in FIGS. 1 to 6 is referred to as “base end”, and the left side is referred to as “tip”.

  A catheter assembly 1 shown in FIG. 1 includes a catheter 11 and a stylet 12. This catheter assembly 1 is inserted into the body through a cannula 10 punctured by the subclavian vein puncture method, and the distal end portion of the catheter 11 is placed in the superior vena cava and used for, for example, high calorie infusion. It is

  As shown in FIG. 3, the catheter 11 includes an elongated catheter body 2 having flexibility (elasticity) and a catheter connector 3 installed on the proximal end side of the catheter body 2.

  A hollow portion (flow channel) 23 is formed inside the catheter body 2 along the longitudinal direction thereof. Although the length of the catheter main body 2 is not specifically limited, Usually, it is preferable that it is 50-1000 mm, and it is more preferable that it is 80-700 mm. The outer diameter of the catheter body 2 is not particularly limited, but is usually preferably 0.3 to 4 mm, more preferably 1 to 3 mm.

  The catheter connector 3 has a cylindrical body portion 31, and the lumen 34 of the body portion 31 communicates with the hollow portion 23 of the catheter body 2. A male screw 311 is formed on the outer periphery of the base end opening of the body portion 31. For example, an infusion tube connector or the like can be connected to the catheter connector 3.

  As shown in FIG. 4, the stylet 12 includes a stylet body 4 formed of a linear body having flexibility (elasticity) that can be inserted into the hollow portion 23 of the catheter body 2, and the stylet body 4. The stylet connector 5 is installed on the proximal end side and is detachable from the catheter connector 3.

  The constituent material of the stylet body 4 is not particularly limited. For example, a metal material such as stainless steel or Ni-Ti alloy, a polymer material having a relatively high elastic modulus such as nylon or polyester, or a combination thereof is preferable. Used.

  As shown in FIG. 5, the stylet connector 5 has a cylindrical body 51. The body portion 51 has a luer taper portion 511 whose outer diameter gradually decreases in the distal direction, and the luer taper portion 511 can be inserted and fitted into the lumen 34 of the catheter connector 3 from the proximal end side. (See FIG. 6). In this way, the stylet connector 5 and the catheter connector can be detachably connected by fitting.

  The body 51 of the stylet connector 5 is formed with a lumen 512 penetrating from the distal end to the proximal end, and a syringe or the like can be connected to the proximal end opening of the body 51. As a result, the tip 22 of the catheter body 2 is inserted into the blood vessel by priming the inside of the catheter 11 with physiological saline or the like without removing the stylet 12 from the catheter 11 or by visually observing the backflow of blood. You can check if it is not.

  When the catheter assembly 1 is inserted up to the target site in the blood vessel, the catheter assembly 1 is in the assembled state shown in FIG. The assembled state is a state in which the stylet body 4 is inserted into the hollow portion 23 of the catheter body 2 and the stylet connector 5 is fitted to the catheter connector 3. In this assembled state, an appropriate rigidity (so-called stiffness) can be obtained in the catheter body 2 by the action of the stylet body 4 inserted inside the catheter body 2, so that the catheter body 2 is inserted into the blood vessel. It becomes easy.

  The length of the stylet body 4 is set such that the tip 41 of the stylet body 4 does not protrude from the tip 22 of the catheter body 2 in the assembled state. Thereby, when the catheter assembly 1 is inserted into the blood vessel, the tip 41 of the stylet body 4 does not hit the blood vessel wall, so that the blood vessel wall can be prevented from being damaged.

  After the catheter assembly 1 is inserted to the target site in the blood vessel, the stylet connector 5 is detached from the catheter connector 3 and the stylet 12 is removed from the catheter 11, and then the catheter connector 3 is connected to, for example, an infusion tube connector. Etc. are connected.

  As shown in FIG. 1, the catheter assembly 1 in the assembled state includes an angle portion 13 formed near the distal end thereof, and a linear portion 14 formed adjacent to the proximal end side of the angle portion 13 and extending linearly. And have. Hereinafter, the shape of the angle portion 13 will be described. The shape described below is a natural state in which an external force is not applied to the catheter assembly 1 (for example, a state in which the catheter assembly 1 is placed on a smooth plane). It is the shape.

  As shown in FIG. 2, the angle portion 13 in the present embodiment includes two curved portions 131 and 132 that are curved in a certain direction (the same direction), and the curved portion 131 is located on the proximal end side. The bending portion 132 is located on the distal end side. In addition, the angle portion 13 includes a straight portion 133 formed between the bending portion 131 and the bending portion 132 and a straight portion 134 formed between the bending portion 132 and the distal end 22 of the catheter body 2. It is out. In such an angle portion 13, since the curved portions 131 and 132 are curved in the same direction, the angle portion 13 is located on substantially the same plane as the straight portion 14.

The angle portion 13 preferably has a shape that satisfies the following conditions. That is, the angle θ formed between the tangent line 100 at the distal end 22 of the catheter body 2 and the straight line portion 14 is preferably 80 to 140 °, more preferably 90 to 130 °, and still more preferably 100 to 125 °. Further, the distal end 22 of the catheter body 2, is preferably the distance _{L 2} between the straight portion 14 or its extension 200 10 to 60 mm, more preferably 20 to 50 mm, more preferably from 35 to 45 mm. Further, the distal end 22 of the catheter body 2, the linear portions 14 of preferably the distance _{L 1} between the plane 300 perpendicular to the straight portion 14 at the tip 141 10 to 60 mm, more preferably 15 to 50 mm, more preferably 20~40mm It is.

Here, the tangent line 100 refers to a tangent line at the center line of the catheter body 2. Further, the distance L ₂ refers to the distance from the center line of the straight line portion 14 or its extension line 200. The distal end 141 of the straight line portion 14 is a boundary point with the curved portion 131 closest to the proximal end of the angle portion 13, that is, a boundary point with a portion that starts to bend.

  Although the length of the linear part 14 is not specifically limited, It is preferable that it is 40-900 mm, and it is more preferable that it is 70-650 mm. Further, in the illustrated configuration, almost the entire portion between the angle portion 13 and the catheter connector 3 is a straight portion 14. However, the configuration is not limited thereto, and the curved portion is not provided between the straight portion 14 and the catheter connector 3. There may be part which we did.

  As shown in FIGS. 8 and 9, in the catheter assembly 1 of the present embodiment, the angle portion 13 having the shape as described above is provided, so that the superior vena cava is passed through the cannula 10 punctured into the subclavian vein. When trying to insert, it can be securely inserted into the superior vena cava without escaping (stray) into other blood vessels (internal jugular vein, external jugular vein, or subclavian vein on the opposite side of the puncture position) The distal end portion of the catheter body 2 can be reliably placed in the optimal placement region of the superior vena cava.

  In particular, not only when the puncture position of the cannula 10 is more on the shoulder side than the vicinity of the bifurcation of the subclavian vein and internal jugular vein, but also the puncture position of the cannula 10 is near the bifurcation point of the subclavian vein and internal jugular vein. Even in some cases, it can be reliably inserted into the superior vena cava without getting into other blood vessels.

  Furthermore, in the catheter assembly 1, the distal end 22 of the catheter body 2 does not collide with the middle blood vessel wall or collides when inserted into the superior vena cava by providing the angle portion 13 having the shape as described above. In this case, since the collision gently occurs at a shallow angle, the stimulation to the blood vessel wall can be reduced, and the blood vessel wall can be reliably prevented from being damaged.

  In the present invention, the number of the curved portions included in the angle portion 13 may be one or three or more, but it is preferable that the angle portion 13 includes a plurality of curved portions as in the present embodiment. Thereby, the indwelling operation to the superior vena cava can be performed more reliably. Specifically, for example, when performing the right subclavian vein puncture, the distal end 22 of the catheter body 2 is opposite to the left subclavian on the opposite side due to the puncture position and puncture angle of the cannula 10, the size of the patient's body, and the like. The insertion into the vein can be prevented more reliably.

Although the curvature radius in the centerline of the curved part 131 of the angle part 13 and the curved part 132 is not specifically limited, It is preferable that it is 5-60 mm, and it is more preferable that it is 10-40 mm. Within such a range, stimulation to the blood vessel wall can be further reduced, and a hand feeling at the time of insertion can be obtained more easily.
In addition, the angle portion 13 may be entirely formed of a curved portion without including the straight portions 133 and 134 and the like.

  Although the catheter assembly 1 has the angle portion 13 as described above in the assembled state, the catheter 11 and the stylet 12 are each in the vicinity of their distal ends even in a single state (a state in which neither is combined). In addition, a catheter angle portion 21 and a stylet angle portion 42 are provided. Hereinafter, the catheter angle portion 21 and the stylet angle portion 42 will be sequentially described.

  As shown in FIG. 3, the catheter body 2 has a catheter angle portion 21 in the vicinity of the distal end thereof. The catheter angle portion 21 includes two curved portions 211 and 212 that are curved in a fixed direction and two straight portions 213 and 214 in a natural state where no external force is applied. The curved portions 211 and 212 and the straight portions 213 and 214 correspond to the curved portions 131 and 132 and the straight portions 133 and 134 of the angle portion 13 in the assembled state, respectively.

  As shown in FIG. 4, the stylet body 4 has a stylet angle portion 42 in the vicinity of the tip thereof. The stylet angle portion 42 is composed of a curved portion 421 that is curved in a certain direction and a straight portion 422 in a natural state where no external force is applied. The curved portion 421 and the straight portion 422 correspond to the curved portion 131 and the straight portion 133 of the angle portion 13 in the assembled state, respectively.

  When the catheter assembly 1 is in a completed state (as shipped), the bending directions of the bending portions 211 and 212 of the catheter angle portion 21 and the bending direction of the bending portion 421 of the stylet angle portion 42 are completely aligned. The catheter connector 3 and the stylet connector 5 are fitted so as to be in a closed state. The angle of the stylet connector 5 with respect to the catheter connector 3 at this time is hereinafter referred to as a “normal angle”.

  Thus, in this embodiment, since the angle portion 13 in the assembled state is formed by the catheter angle portion 21 and the stylet angle portion 42 formed in the catheter 11 and the stylet 12, respectively, the blood vessel of the catheter assembly 1 is formed. The shape retaining property of the angle portion 13 can be further improved during insertion into the device, and as a result, the angle portion 13 can be more reliably inserted into the target site.

  Now, the catheter assembly 1 of the present invention has a fitting state restricting means 15 for restricting the fitting state between the catheter connector 3 and the stylet connector 5. The fitting state restricting means 15 allows the catheter connector 3 and the stylet connector 5 to be fitted only when the bending direction of the catheter angle portion 21 and the bending direction of the stylet angle portion 42 are substantially aligned, and the catheter angle portion 21 can be fitted. In the state where the connector 3 and the stylet connector 5 are fitted to each other, the angle θ at which the two can rotate relative to each other is restricted to a predetermined range. Hereinafter, the fitting state restricting means 15 will be described.

  As shown in FIG. 5, the fitting state restricting means 15 is provided on the protrusion 53 formed so as to protrude from the outer peripheral surface of the luer taper portion 511 of the stylet connector 5 and the inner peripheral surface of the lumen 34 of the catheter connector 3. It is comprised with the recessed part 35 formed. The protrusion 53 is formed in the lower part of the luer taper part 511 in FIG. 5, and the concave part 35 is formed in the vicinity of the proximal end of the catheter connector 3 and in the lower part in FIG. 5.

  As shown in FIG. 6, when the luer taper portion 511 of the stylet connector 5 is inserted into the lumen 34 of the catheter connector 3, the protrusion 53 is inserted into the recess 35 when the positions of the protrusion 53 and the recess 35 are aligned. The let connector 5 is fitted to the catheter connector 3. At this time, the bending direction of the catheter angle portion 21 and the bending direction of the stylet angle portion 42 are substantially aligned. That is, the protrusion 53 cannot be inserted into the recess 35 unless the catheter connector 3 and the stylet connector 5 are in the vicinity of the normal angle.

  On the other hand, when the positions of the protrusion 53 and the recess 35 are not aligned, the stylet connector 5 cannot be fitted to the catheter connector 3 by the protrusion 53 coming into contact with the proximal end surface 36 of the catheter connector 3. Therefore, by providing such a fitting state restricting means 15, the stylet connector 5 and the catheter connector 3 are in a state where the bending direction of the catheter angle portion 21 and the bending direction of the stylet angle portion 42 are not aligned. It can prevent fitting and connection. Accordingly, in the present invention, it is possible to reliably prevent the bending direction of the angle portion 13 of the catheter assembly 1 from being deviated, and adverse effects caused by the deviating bending direction of the angle portion 13 (such as straying when inserted into a body cavity) ) Can be reliably prevented.

  Immediately before using the catheter assembly 1, the doctor makes a fit between the stylet connector 5 and the catheter connector 3 in order to check whether the stylet connector 5 and the catheter connector 3 are not fixed due to blocking or the like. In many cases, the operation of re-fitting is performed after removing it. In the catheter assembly 1 of the present invention, when the doctor performs this operation, the bending direction of the catheter angle portion 21 and the bending direction of the stylet angle portion 42 are not aligned (a state greatly deviated from the normal angle). It is possible to reliably prevent the stylet connector 5 and the catheter connector 3 from re-fitting.

  As shown in FIG. 7, the concave portion 35 is formed larger than the projection 53, and the projection 53 can move inside the concave portion 35. Thereby, the catheter connector 3 and the stylet connector 5 can be relatively rotated around the central axis Ax within a predetermined angle range in a fitted state. In this case, in the present invention, the angle θ at which the catheter connector 3 and the stylet connector 5 can relatively rotate is preferably 5 to 40 °, more preferably 5 to 30 °, and still more preferably 5 to 20 °. .

  At this time, when the protrusion 53 is located at the position shown by the solid line in FIG. 7, the bending direction of the catheter angle portion 21 and the bending direction of the stylet angle portion 42 completely coincide with each other. It is preferable that it can rotate with respect to the catheter connector 3 by the same angle (θ / 2) clockwise and counterclockwise in the figure.

  When the angle θ is in the range of 5 to 40 °, both the attachment and detachment of the stylet connector 5 and the catheter connector 3 and the prevention of the bending direction of the angle portion 13 of the catheter assembly 1 are prevented. Can do.

  That is, as can be seen from the results of Experiment 1 to be described later, when the angle θ is less than 5 °, the stylet connector 5 and the catheter connector 3 are twisted together to release or re-fit the two. However, in the present invention, since the angle θ is set to 5 ° or more, there is enough room for the stylet connector 5 and the catheter connector 3 to rotate relative to each other. Can be done.

  Further, as can be seen from the result of Experiment 2 described later, when the angle θ exceeds 40 °, the stylet connector 5 rotates to the maximum within the range of relative rotation with respect to the catheter connector 3, and the catheter assembly 1 The angle portion 13 of the angle portion 13 is greatly deviated, and it may be difficult to insert into the target site in the body cavity, leading to straying.In the present invention, the angle θ is set to 40 ° or less, The angle portion 13 of the catheter assembly 1 can be within an allowable range of deviation in the bending direction (a range in which the catheter assembly 1 can be easily inserted into a target site within the body cavity).

  Further, in the configuration shown in the figure, the protrusion 53 is formed at a position on the curved inner side of the stylet angle portion 42. Thereby, the protrusion 53 also exhibits the function of indicating the bending direction of the stylet angle portion 42.

(Experiment 1)
In Experiment 1, first, a catheter assembly similar to that shown in FIGS. 1 to 7, wherein the relative rotatable angle θ between the catheter connector 3 and the stylet connector 5 is different between 1 to 10 °. Four types were produced. The catheter connector 3 and the stylet connector 5 were each made of polypropylene resin.

  Using these four types of catheter assemblies, the operability when the stylet body 4 is inserted into the catheter body 2 to fit the catheter connector 3 and the stylet connector 5, and the catheter connector 3 and the stylet connector The operability when the stylet body 4 was removed from the catheter body 2 by releasing the fitting with 5 was evaluated. The evaluation results are summarized in Table 1 below. In Table 1, “O” indicates that the operability is good, and “X” indicates that the operation is difficult.

  As can be seen from the results of Experiment 1 shown in Table 1, if the relative rotatable angle θ between the catheter connector 3 and the stylet connector 5 is 5 ° or more, good operability can be obtained during insertion and removal. Became clear.

(Experiment 2)
FIG. 10 is a diagram showing a blood vessel model used in Experiment 2. In Experiment 2, first, three types of catheter assemblies similar to those shown in FIGS. 1 to 6 except that the fitting state restricting means 15 is not provided and different in outer diameter of the catheter body 2 were produced. . The main specifications of this catheter assembly are as follows. The catheter body 2 is made of thermoplastic polyurethane (polycarbonate polyurethane, Shore hardness 98A), which is a flexible synthetic resin. The outer diameter of the catheter body 2 in each of the three types of catheter assemblies is 1.15 mm (18 G), respectively. ), Φ1.50 mm (16 G), φ 2.70 mm (14 G). The effective length of the catheter body 2 was 300 mm. The stylet body 4 was made of a spring wire made of stainless steel having an outer diameter of φ0.6 mm. The length of the stylet body 4 was such that the distance between the tip 22 of the catheter body 2 and the tip 41 of the stylet body 4 in the assembled state was 20 mm. The catheter connector 3 and the stylet connector 5 were each made of polypropylene resin.

Further, the shape of the angle portion 13 in this catheter assembly was a shape including two curved portions 131 and 132 as shown in FIG. 2, and the dimensions of each portion were as follows. The angle θ formed between the tangent line 100 at the distal end 22 of the catheter body 2 and the straight line portion 14 was set to 85 °. The distal end 22 of the catheter body 2, the distance _{L 1} between the plane 300 perpendicular to the straight portion 14 at the tip 141 of the straight portion 14 was set to 25 mm. The distal end 22 of the catheter body 2, the straight portion 14 or the distance _{L 2} between the extended line 200 was set to 40 mm.

  Using the three types of catheter assemblies prepared as described above, the following insertion operability test was performed. A blood vessel model as shown in FIG. 10 was prepared, and a cannula 10 was punctured into the subclavian vein of this blood vessel model. The puncture position of the cannula 10 was a position where the distance from the branch portion with the internal jugular vein was 20 mm, the puncture angle was 30 °, and the puncture depth was 8 mm. An experiment for inserting the catheter assembly from the cannula 10 was performed, and it was confirmed whether or not the catheter assembly could be smoothly inserted into the superior vena cava. Such an insertion operability test is performed by changing the rotation angle (θ / 2) from the normal angle of the stylet connector 5 with respect to the catheter connector 3 in 18 stages within a range of −60 to + 60 °, and 20 times at each angle. Each test was performed, and the number of times that the tip of the inserted catheter assembly strayed (entered) into the internal jugular vein was counted. Here, the rotation angle of the stylet connector 5 with respect to the catheter connector 3 is the case where the stylet connector 5 is rotated clockwise from the normal angle in the state corresponding to FIG. Is -rotation. The results of the insertion operability test (Experiment 2) as described above are summarized in Table 2.

  From the result of the insertion operability test (Experiment 2) shown in Table 2, if the rotation angle of the stylet connector 5 with respect to the catheter connector 3 from the normal angle is ± 20 °, the bending direction of the angle portion 13 is allowed to be misaligned. As a result, it was found that the catheter assembly can be smoothly inserted into the superior vena cava without straying. In the case of the catheter assembly 1 of the present invention, since the angle θ is set to 40 ° or less, the rotation angle from the normal angle of the stylet connector 5 with respect to the catheter connector 3 is always in the range of ± 20 °. The catheter assembly 1 can be smoothly inserted into the superior vena cava without straying.

  In the catheter assembly 1 of this embodiment, as described above, the tip 41 of the stylet body 4 does not protrude from the tip 22 of the catheter body 2 in the assembled state. The distance between the distal end 22 of the catheter body 2 and the distal end 41 of the stylet body 4 in the assembled state (length along the center line of the catheter body 2) is not particularly limited, but is preferably 15 to 40 mm. More preferably, it is 20-30 mm. If this distance is less than the lower limit, depending on conditions such as the material and outer diameter of the catheter body 2, the catheter body 2 may be easily twisted during insertion into the blood vessel. When this distance exceeds the upper limit, depending on conditions such as the material and outer diameter of the catheter body 2, the catheter body 2 in the portion where the stylet body 4 is not inserted forms a loop when inserted into the blood vessel. It may be difficult to insert.

  Further, in the assembled state, the length of the portion where the angle portion 13 and the stylet body 4 overlap is preferably about 50 to 90% with respect to the total length of the angle portion 13, and is about 70 to 85%. More preferably.

  In the present invention, the catheter body 2 and the stylet body 4 may have a constant rigidity along the longitudinal direction, but may have a portion where the rigidity gradually decreases in the distal direction. Thereby, the catheter assembly 1 can express the inclination physical property in an assembly state.

  In the present invention, the stylet body 4 may have a circular cross-sectional shape, but may have other shapes, for example, a rectangular or elliptical cross-sectional shape. In this case, since the stylet body 4 has a direction that is easy to bend and a direction that is difficult to bend, the stylet body 4 is combined with the catheter 11 in a state in which the easy-bend direction is matched with the bending direction of the angle portion 13. Twist generated in the catheter body 2 during insertion can be further reduced.

  A constituent material of the catheter body 2 in the present invention is not particularly limited, and a synthetic resin material having flexibility can be mainly used. However, a polymer elastomer is preferable, and a thermoplastic polyurethane is particularly preferable. More preferred.

  Thermoplastic polyurethane has high biocompatibility and blood compatibility, and is also suitable for relatively long-term indwelling. In addition, after the polymer elastomer is changed into a desired shape, it is subjected to a heat treatment at a temperature equal to or higher than the glass transition temperature of the polymer elastomer and cooled in its shape, thereby exhibiting shape memory properties. It is also possible to change the shape to a desired shape, which is preferable because the shape can be changed to a desired angle and curvature even when the catheter angle portion 21 is formed.

  The outer surface of the catheter body 2 may be provided with a coating that exhibits lubricity when it comes into contact with a biological tissue such as body fluid, blood, mucous membrane or the like. Constituent materials for this coating include water-soluble polymers, specifically, polyvinylpyrrolidone, methyl vinyl ether sodium maleate anhydride, polyacrylamide hydrolyzate, sodium alginate, polyvinyl sulfonate sodium salt, methyl vinyl ether maleic acid ammonium salt And polyacrylamide quaternary compounds. When such a coating is applied, the outer surface of the catheter body 2 is lightly wiped with gauze or the like soaked in heparinized physiological saline, for example, so that the water-soluble polymer can be moistened to exhibit lubricity.

  Further, in the catheter assembly 1 of the present embodiment, as shown in FIG. 1, the stylet connector 5 has a protrusion 52 that indicates the bending direction of the bending portions 131 and 132 of the angle portion 13. The protrusion 52 is formed so as to protrude from the body portion 51. The protrusion 52 has a protruding length such that it can be easily recognized by a sense (tactile sense) touched with a finger, and the preferable protruding length is about 1 to 20 mm.

  The protrusion 52 has a plate shape (flat plate shape), and is positioned substantially on the same plane as the angle portion 13 (on the same plane as the paper surface of FIG. 1). Further, the protrusion 52 protrudes in the direction of the inside of the curved portions 131 and 132 of the angle portion 13, whereby the protrusion 52 shows the bending direction of the curved portions 131 and 132 of the angle portion 13 more easily. be able to.

  By providing such a protrusion 52, the doctor can change the bending direction of the angle portion 13 not only when the stylet connector 5 is visually observed but also by a sense (tactile sense) of touching the stylet connector 5 with fingers. It can be easily recognized. Thereby, since the doctor can easily recognize the bending direction of the angle portion 13 without looking at the hand, the insertion operation of the catheter assembly 1 can be performed smoothly and accurately.

  The protrusion 52 also has a function as a finger pad for rotating the stylet connector 5 with respect to the catheter connector 3. Thus, when the doctor twists the stylet connector 5 and the catheter connector 3 to release the fitting state between them and refits them, the doctor places a finger on the protrusion 52 and rotates the stylet connector 5. By doing so, the finger can be rotated easily without slipping.

  As shown in FIG. 5, in the present embodiment, the base end portion 43 of the stylet body 4 is fixed to the stylet connector 5 while being embedded in the above-described protrusion 52. Thereby, since the stylet body 4 and the stylet connector 5 can be more firmly fixed, even if a tensile load acts between both, the stylet body 4 and the stylet connector 5 It is possible to more reliably prevent the fixation of.

  In the catheter assembly 1 of the present embodiment, the catheter connector 3 is also provided with protrusions 32 and 33 that indicate the bending directions of the bending portions 131 and 132 of the angle portion 13. The protrusions 32 and 33 are formed so as to protrude from the body portion 31. Each of the protrusions 32 and 33 has a protruding length that can be easily recognized by a sense (tactile sense) touched with a finger, and a preferable protruding length is about 1 to 20 mm.

  Each of the protrusions 32 and 33 has a plate shape (flat plate shape), and is located on substantially the same plane as the angle portion 13 (on the same plane as the paper surface of FIG. 1). Further, the protrusions 32 and 33 protrude in opposite directions from the body portion 31 via the central axis of the catheter connector 3 (body portion 31), and one protrusion 32 is formed on the curved portions 131 and 132 of the angle portion 13. The other projection 33 protrudes in the direction of the curved outer side of the curved portions 131 and 132.

  The protrusions 32 and 33 are different from each other in shape and size, and the protrusion 32 is formed to extend longer to the base end side than the protrusion 33. Thus, the protrusions 32 and 33 can be identified not only by visual observation, but also by touching with fingers. Therefore, the doctor can easily recognize the bending direction of the angle portion 13 by touching the protrusions 32 and 33 with fingers and identifying their orientations.

  In the present embodiment, by providing such protrusions 32 and 33 on the catheter connector 3, the doctor can easily recognize the bending direction of the angle portion 13 even by touching the catheter connector 3 with fingers. Therefore, the insertion operation of the catheter assembly 1 can be performed more smoothly and accurately.

  Further, the protrusions 32 and 33 also have a function as a finger contact portion for rotating the catheter connector 3 relative to the stylet connector 5 and the like. Thus, when the doctor twists the stylet connector 5 and the catheter connector 3 to release or refit the fitting state of the two, the doctor connector connects or releases the infusion tube connector or the like to the catheter connector 3. When performing the operation, the finger is applied to the protrusions 32 and 33 and the catheter connector 3 is gripped, so that the finger can be gripped without slipping and can be rotated relatively easily. In particular, in the present embodiment, this effect is more remarkably exhibited by providing the protrusions 32 and 33 protruding in opposite directions.

  In addition, as described above, immediately before the catheter assembly 1 is inserted into the living body, the doctor may rotate the stylet connector 5 and the catheter connector 3 relatively to confirm their movements. In this embodiment, since both the stylet connector 5 and the catheter connector 3 are provided with protrusions, the relative rotational positions of the stylet connector 5 and the catheter connector 3 are accurately determined after confirming the movement. It is possible to return to the state and reliably prevent the rotation position from being out of order.

  FIG. 11 is a longitudinal sectional view for explaining another configuration example of the fitting state regulating means in the catheter assembly of the present invention. 11A includes a protrusion 54 formed so as to protrude from the outer peripheral surface of the luer taper portion 511 of the stylet connector 5 and a recess 37 formed on the proximal end surface 36 of the catheter connector 3. It is configured. The protrusion 54 is L-shaped and protrudes toward the distal end. When the stylet connector 5 is fitted to the catheter connector 3, the protrusion 54 is inserted into the recess 37. The protrusions 54 and the recesses 37 are respectively provided above and below in FIG. As described above, a plurality of sets of the protrusions 54 and the concave portions 37 constituting the fitting state regulating means 15A may be provided.

  FIG. 12 is a longitudinal sectional view for explaining still another configuration example of the fitting state regulating means in the catheter assembly of the present invention, and FIG. 13 is a transverse sectional view taken along line YY in FIG. As shown in FIG. 12, the proximal end portion 38 of the catheter connector 3 in this configuration example is formed with an elliptical lumen 381 whose inner peripheral surface has an elliptical cross-sectional shape. In addition, an elliptical portion 513 is formed on the proximal end side of the luer taper portion 511 of the stylet connector 5. When the stylet connector 5 is fitted to the catheter connector 3, the oval part 513 is inserted into the oval lumen 381. The fitting state restricting means 15 </ b> B of this configuration example is configured by the elliptical lumen 381 and the elliptical part 513.

  As shown in FIG. 13, the ellipse 513 can rotate to the state indicated by A in the clockwise direction in FIG. 13 and can rotate to the state indicated by B in the counterclockwise direction. It has become. As a result, the angle θ at which the catheter connector 3 and the stylet connector 5 can be relatively rotated in a state where the catheter connector 3 and the stylet connector 5 are fitted is regulated. In the case of this configuration example, there is no need to provide protrusions or recesses, so the shapes of the catheter connector 3 and the stylet connector 5 are simplified and can be easily manufactured.

  As mentioned above, although the catheter assembly of this invention was demonstrated about embodiment of illustration, this invention is not limited to this, Each part which comprises a catheter assembly is arbitrary structures which can exhibit the same function Can be substituted. Moreover, arbitrary components may be added.

  In the present invention, the catheter body may be composed of a porous tube having a plurality of hollow portions (flow paths). In that case, the catheter has a plurality of catheter connectors communicating with the respective hollow portions. May be.

  The present invention can be applied not only to high-calorie intravenous catheters placed in the superior vena cava, but also to catheters for various other purposes.

It is a side view which shows embodiment of the catheter assembly of this invention. FIG. 2 is an enlarged side view showing the vicinity of the distal end of the catheter assembly shown in FIG. 1. It is a side view which shows the catheter in the catheter assembly shown in FIG. It is a side view which shows the stylet in the catheter assembly shown in FIG. FIG. 2 is an enlarged longitudinal sectional view showing the vicinity of a stylet connector and a catheter connector in the catheter assembly shown in FIG. 1. FIG. 2 is an enlarged longitudinal sectional view showing the vicinity of a stylet connector and a catheter connector in the catheter assembly shown in FIG. 1. XX line cross-sectional view in FIG. It is a figure which shows typically a mode that the catheter assembly shown in FIG. 1 is inserted in the superior vena cava. It is a figure which shows typically a mode that the catheter assembly shown in FIG. 1 is inserted in the superior vena cava. It is a figure which shows the blood vessel model used by the insertion operativity test (Experiment 2). It is a longitudinal cross-sectional view for demonstrating the other structural example of the fitting state control means in the catheter assembly of this invention. It is a longitudinal cross-sectional view for demonstrating the further another structural example of the fitting state control means in the catheter assembly of this invention. FIG. 13 is a cross-sectional view taken along line YY in FIG. 12. It is the schematic of the blood vessel near the superior vena cava (central vein) when the patient is facing the front. It is the schematic of the blood vessel near the upper vena cava (central vein) when the patient is facing the left direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Catheter assembly 11 Catheter 12 Stylet 13 Angle part 131,132 Curved part 133,134 Linear part 14 Linear part 141 Tip 15,15A, 15B Fitting state control means 2 Catheter body 21 Catheter angle part 211,212 Curved part 213 , 214 Straight part 22 Tip 23 Hollow part 3 Catheter connector 31 Body 311 Male screw 32, 33 Projection 34 Lumen 35 Recess 36 Base end face 37 Recess 38 Base end part 4 Stylet body 41 Tip 42 Stylet angle part 421 Curved part 422 Linear portion 43 Base end portion 5 Stylet connector 51 Body portion 511 Luer taper portion 512 Lumen 513 Ellipse portion 52 Protrusion 53, 54 Protrusion 10 Cannula 100 Tangent 200 Extension line 300 Planar Ax Central axis

Claims (8)

A catheter having a flexible catheter body in which a hollow portion is formed along the longitudinal direction, and a catheter connector installed on the proximal end side of the catheter body;
A stylet body composed of a flexible linear body that can be inserted into the hollow portion of the catheter body, and is installed on the proximal end side of the stylet body and is detachable by fitting to the catheter connector. A catheter assembly comprising a stylet having a stylet connector,
The catheter body is formed near its tip, and has a curved catheter angle portion in a single state,
The stylet body has a stylet angle portion formed in the vicinity of the tip thereof and curved in a shape corresponding to the catheter angle portion in a single state,
The catheter connector and the stylet connector can be fitted only in a state where the bending direction of the catheter angle portion and the bending direction of the stylet angle portion are substantially aligned, and the catheter connector and the stylet connector A catheter assembly comprising a fitting state restricting means for restricting an angle at which the two members can rotate relative to each other in a state where they are fitted.   The catheter assembly according to claim 1, wherein the fitting state restricting means restricts an angle in which the catheter connector and the stylet connector can be relatively rotated in a state where the catheter connector and the stylet connector are fitted to each other in a range of 5 to 40 °.   The distal end of the stylet body does not protrude from the distal end of the catheter body when the stylet body is inserted into the hollow part of the catheter body and the stylet connector is fitted to the catheter connector. 3. The catheter assembly according to 2.   The fitting state restricting means includes at least one protrusion provided on the stylet connector and a recess provided on the catheter connector into which the protrusion can be inserted. A catheter assembly as described.   The catheter assembly according to claim 4, wherein the protrusion also has a function of indicating a bending direction of the stylet angle portion.   The fitting state restricting means is provided in the catheter connector and has an elliptical lumen whose inner peripheral surface has an elliptical cross-sectional shape and the stylet connector, and has a cross-sectional shape of the outer peripheral surface as the elliptical lumen. The catheter assembly according to any one of claims 1 to 3, wherein the catheter assembly has a smaller oval shape and is configured to be inserted into the oval lumen.   The said stylet connector is provided with the processus | protrusion which has a function as a finger | toe contact part for rotating the said stylet connector with respect to the said catheter connector while showing the bending direction of the curved part of the said stylet angle part. 7. The catheter assembly according to any one of 6. The said catheter connector is provided with the processus | protrusion which has a function as a finger | toe contact part for rotating the said stylet connector and the said catheter connector relatively while showing the bending direction of the bending part of the said catheter angle part. 8. The catheter assembly according to any one of 7 to 7.

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