JP6730430B2 - Percutaneous catheter assembly, percutaneous catheter, and dilator - Google Patents

Description

The present invention relates to percutaneous catheter assemblies, percutaneous catheters, and dilators.

BACKGROUND ART Conventionally, in order to perform cardiopulmonary resuscitation, circulatory support, and respiratory support in emergency treatment, treatment by a percutaneous cardiopulmonary support (PCPS) is performed. The percutaneous cardiopulmonary support method is a method of temporarily assisting/substituting for cardiopulmonary function using an extracorporeal circulation device.

The extracorporeal circulation device is provided with an extracorporeal circulation circuit including a centrifugal pump, an artificial lung, a blood removal path, a blood supply path, and the like, and exchanges gas with respect to the blood that has been removed, and supplies the blood to the blood supply path.

In connection with this, for example, Patent Document 1 below describes a circulation circuit of an extracorporeal circulation device.

International publication number WO2007/123156

When blood circulation is performed in this circulation circuit, blood is circulated by the force of a pump driven by a motor. Therefore, in order to perform the blood circulation properly, it is required to reduce the pressure loss in the tubes forming the circulation circuit.

However, if the inner diameter of the tube is small, the pressure loss becomes high and the flow rate flowing through the circulation circuit decreases. Therefore, unless the inner diameter of the tube is made sufficiently large, the required blood circulation amount cannot be obtained.

On the other hand, increasing the inner diameter of the tube also increases the outer diameter of the tube. Therefore, if the inner diameter of the blood removal catheter (tube) or the blood supply catheter (tube) that is inserted into the patient's body is increased, the degree of invasion of the patient's body increases and the burden on the patient's body increases.

Therefore, the present invention suppresses the burden on the patient's body, reduces the pressure loss of the liquid circulating in the circulation circuit, and secures the required flow rate of the liquid, a percutaneous catheter assembly, And to provide a dilator.

A percutaneous catheter assembly that achieves the above object is a percutaneous catheter assembly that includes a percutaneous catheter for passing blood and a dilator that is inserted into the percutaneous catheter. The percutaneous catheter includes a catheter tube that has a distal end portion that is open at the distal end in the insertion direction and that extends in the axial direction. The dilator includes a first dilator that extends in the axial direction and the first dilator. A second dilator configured to be relatively movable in the axial direction with respect to the dilator, and the tip portion is sandwiched between the first dilator and the second dilator. And the gripping state by the first dilator and the second dilator is released by the relative movement of the first dilator with respect to the second dilator in the axial direction. The catheter tube is extended in the axial direction by moving toward the distal end side in the insertion direction with the first dilator and the second dilator holding the distal end portion, and the outer diameter is reduced. The outer diameter is expanded by contracting in the axial direction by releasing the gripped state.

A dilator that achieves the above object is a dilator that is inserted into a percutaneous catheter. The dilator includes a first dilator extending in the axial direction and a second dilator configured to be movable relative to the first dilator in the axial direction. The dilator expands the catheter tube along with the second dilator in the axial direction by sandwiching the distal end portion opened at the distal end in the insertion direction of the catheter tube and moving to the distal end side while gripping the distal end portion. The outer diameter of the catheter tube is reduced, and the gripping state of the distal end portion is released as the first dilator moves relative to the second dilator in the axial direction. Shrinks in the direction and the outer diameter expands.

According to the percutaneous catheter assembly, the percutaneous catheter, and the dilator configured as described above, the first dilator and the second dilator move toward the distal end side in the insertion direction while holding the distal end portions. The outer diameter can be reduced by extending the catheter tube in the axial direction. Therefore, by inserting the percutaneous catheter into the living body with the outer diameter of the catheter tube reduced, it is possible to suppress the burden on the body of the patient. Further, after the percutaneous catheter is placed in the living body, the first dilator is moved relative to the second dilator in the axial direction, so that the distal ends of the first dilator and the second dilator are grasped. The state is released. As a result, the catheter tube contracts in the axial direction and the outer diameter increases. Therefore, the pressure loss in the catheter tube is reduced, and the required liquid flow rate can be secured. From the above, it is possible to suppress the burden on the patient's body, reduce the pressure loss of the liquid circulating in the circulation circuit, and secure the required flow rate of the liquid.

1 is a system diagram showing an example of an extracorporeal circulation device to which a percutaneous catheter according to an embodiment of the present invention is applied. It is a side view which shows a catheter assembly before inserting a dilator into the inside of a catheter. It is a side sectional view showing a catheter assembly after inserting a dilator inside a catheter. It is a side sectional view showing a state where the tip part of a catheter was grasped by the first dilator and the second dilator. It is a side surface sectional view showing signs that the 1st tube was prolonged in the direction of an axis. It is a side surface sectional view showing the tip of the 1st tube. It is a front view which shows a connector. It is a figure for demonstrating the usage method of a catheter assembly. It is a top view which shows the catheter assembly which concerns on 2nd Embodiment. It is a side sectional view showing a catheter concerning a 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description does not limit the technical scope or the meaning of terms used in the claims. Further, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may differ from the actual ratios.

FIG. 1 shows a case in which a percutaneous catheter according to an embodiment of the present invention is applied to temporarily assist and substitute the functions of the heart and lungs until the heart function is restored when the patient's heart is weak. It is a systematic diagram which shows an example of the extracorporeal circulation device used as a percutaneous cardiopulmonary support method (PCPS).

According to the extracorporeal circulation device 1, the pump is operated to remove blood from the patient's vein (caval vein), and the oxygenation of the blood is performed by exchanging gas in the blood with the artificial lung, and then the blood is recovered again. A procedure of a venous-arterial system (Veno-Arterial, VA) for returning to a patient's artery (aorta) can be performed. The extracorporeal circulation device 1 is a device that assists the heart and lungs. Hereinafter, a procedure of removing blood from a patient, performing a predetermined treatment outside the body, and then sending blood again to the body of the patient is referred to as “extracorporeal circulation”.

As shown in FIG. 1, the extracorporeal circulation device 1 has a circulation circuit for circulating blood. The circulation circuit includes an artificial lung 2, a centrifugal pump 3, a drive motor 4 that is a drive unit for driving the centrifugal pump 3, a venous catheter (percutaneous catheter for blood removal) 5, and an arterial catheter ( It has a blood feeding catheter) 6 and a controller 10 as a control unit.

The vein side catheter (blood removal catheter) 5 is inserted from the femoral vein, and the tip of the vein side catheter 5 is placed in the right atrium via the inferior vena cava. The vein side catheter 5 is connected to the centrifugal pump 3 via a blood removal tube (blood removal line) 11. The blood removal tube 11 is a conduit for sending blood.

The arterial catheter (blood supply catheter) 6 is inserted from the femoral artery.

When the drive motor 4 operates the centrifugal pump 3 according to the command SG of the controller 10, the centrifugal pump 3 removes blood from the blood removal tube 11 and passes blood through the artificial lung 2, and then the blood supply tube (blood supply line). Blood can be returned to the patient P via 12.

The artificial lung 2 is arranged between the centrifugal pump 3 and the blood supply tube 12. The artificial lung 2 performs gas exchange (oxygen addition and/or carbon dioxide removal) for blood. The artificial lung 2 is, for example, a membrane oxygenator, but a hollow fiber membrane oxygenator is particularly preferably used. Oxygen gas is supplied from the oxygen gas supply unit 13 to the artificial lung 2 through the tube 14. The blood supply tube 12 is a conduit connecting the artificial lung 2 and the arterial catheter 6.

As the blood removal tube 11 and the blood supply tube 12, for example, a conduit made of a synthetic resin such as vinyl chloride resin or silicone rubber that has high transparency and is elastically deformable and flexible can be used. In the blood removal tube 11, liquid blood flows in the V1 direction, and in the blood supply tube 12, blood flows in the V2 direction.

In the circulation circuit shown in FIG. 1, the ultrasonic bubble detection sensor 20 is arranged in the middle of the blood removal tube 11. The fast clamp 17 is arranged in the middle of the blood supply tube 12.

The ultrasonic bubble detection sensor 20 detects the mixed bubbles when the bubbles are mixed in the circulation circuit due to an erroneous operation of the three-way stopcock 18 or damage to the tube during extracorporeal circulation. When the ultrasonic bubble detection sensor 20 detects that there is a bubble in the blood sent to the blood removal tube 11, the ultrasonic bubble detection sensor 20 sends a detection signal to the controller 10. Based on this detection signal, the controller 10 notifies an alarm by an alarm and lowers the rotation speed of the centrifugal pump 3 or stops the centrifugal pump 3. Further, the controller 10 instructs the fast clamp 17 to immediately close the blood supply tube 12 by the fast clamp 17. This prevents bubbles from being sent into the body of the patient P. The controller 10 controls the operation of the extracorporeal circulation device 1 to prevent air bubbles from entering the body of the patient P.

The tube 11 (12, 19) of the circulation circuit of the extracorporeal circulation device 1 is provided with a pressure sensor. The pressure sensor is, for example, either the mounting position A1 of the blood removal tube 11, the mounting position A2 of the blood supply tube 12 of the circulation circuit, or the mounting position A3 of the connection tube 19 that connects between the centrifugal pump 3 and the artificial lung 2. It can be attached to one or all. Accordingly, the pressure inside the tube 11 (12, 19) can be measured by the pressure sensor while the extracorporeal circulation device 1 is performing the extracorporeal circulation on the patient P. The mounting position of the pressure sensor is not limited to the mounting positions A1, A2, and A3 described above, and the pressure sensor can be mounted at any position in the circulation circuit.

<First Embodiment>
A percutaneous catheter assembly (hereinafter, referred to as “catheter assembly”) 100 according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 7. 2 to 7 are diagrams for explaining the configuration of the catheter assembly 100 according to the first embodiment.

As shown in FIG. 2, the catheter assembly 100 according to the present embodiment includes a percutaneous catheter (hereinafter, referred to as “catheter”) 30 for passing blood, and a dilator 50 inserted through the catheter 30. Have. The catheter 30 is used as the vein side catheter (blood removal catheter) 5 in FIG.

In the present specification, the side to be inserted into the living body is referred to as “tip” or “tip side”, and the hand side operated by the operator is referred to as “base end” or “base end side”. The tip part means a certain range including the tip (the most distal end) and the periphery thereof, and the base end part means a certain range including the base end (the most proximal end) and the periphery thereof.

As shown in FIG. 2, the catheter 30 according to the present embodiment includes a catheter tube 31, a connector 45 having a side hole 63, a clamping tube 34 arranged on the proximal end side of the catheter tube 31, and a catheter tube 31. Also, a catheter connector 35 for connecting the clamp tube 34 and a lock connector 36 are provided.

As shown in FIG. 3, the catheter 30 has a lumen 30A that penetrates from the distal end to the proximal end and into which the dilator 50 can be inserted.

As shown in FIG. 2, the catheter tube 31 has a first tube 32 and a second tube 33 connected to the base end side of the first tube 32 via a connector 45.

The first tube 32 is configured to have higher elasticity than the second tube 33. Further, the first tube 32 is configured to have a larger outer diameter and inner diameter than the second tube 33. An open front end portion 32 a is provided at the front end of the first tube 32. The side holes 63 provided in the distal end portion 32a and the connector 45 are arranged on different blood removal targets in the living body, and are configured to perform blood removal efficiently.

As shown in FIG. 4, the tip portion 32a is configured to be graspable by a first dilator 51 and a second dilator 52 described later. As shown in FIGS. 2 and 3, the tip portion 32a is configured to have the same outer diameter as the maximum outer diameter of the first tube 32 in a state where it is not gripped by the first dilator 51 and the second dilator 52. There is. Here, for example, when the tip of the first tube is attached to the tip of the first tube to prevent the first tube from collapsing during blood removal, the inner diameter of the tip is smaller than that of the first tube. The small size results in high pressure loss in the lumen of the tip. On the other hand, according to the catheter 30 according to the present embodiment, the distal tip is not provided, and the distal end portion 32a is configured to have the same outer diameter as the maximum outer diameter of the first tube 32. Compared with the configuration in which the tip is provided at the tip of one tube, the pressure loss can be further reduced.

The lengths of the first tube 32 and the second tube 33 are configured to be the lengths necessary for disposing the distal end portion 32a and the side hole 63 of the connector 45 in a desired blood removal target. The length of the first tube 32 can be, for example, 20 to 40 cm, and the length of the second tube 33 can be, for example, 20 to 30 cm.

In the present embodiment, blood removal targets are the right atrium and the inferior vena cava. The catheter 30 is inserted and left in the living body so that the distal end portion 32a is located in the right atrium and the side hole 63 of the connector 45 is located in the inferior vena cava.

The first tube 32 is placed in the inferior vena cava, which is a relatively thick blood vessel, and the second tube 33 is placed in the femoral vein, which is a relatively thin blood vessel, with the tip portion 32a and the side hole 63 being placed in the blood removal target. Will be placed.

When the dilator 50 is moved to the tip side while the dilator 50 holds the tip portion 32a, the first tube 32 having high elasticity expands and contracts in the axial direction as shown in FIG. The inner diameter becomes smaller. At this time, the outer diameter of the first tube 32 is substantially the same as the outer diameter of the second tube 33. Since the catheter 30 is inserted into the living body in a state where the outer diameter and the inner diameter are reduced by extending the first tube 32 in the axial direction, the catheter 30 can be inserted minimally invasively. The method by which the dilator 50 grips the tip portion 32a will be described later.

In addition, after the catheter 30 is left in the living body, when the gripped state of the distal end portion 32a of the dilator 50 is released, the first tube 32 contracts from the axially extended state and the inner diameter increases. Here, the first tube 32 is arranged in the inferior vena cava, which is a relatively thick blood vessel. Therefore, the outer diameter of the first tube 32 can be increased, and the inner diameter can be increased accordingly. A method of releasing the gripped state of the tip portion 32a of the dilator 50 will be described later.

Here, the pressure loss in the first tube 32 is the total length of the first tube 32×(average) passage cross-sectional area. That is, by increasing the inner diameter of the first tube 32, the pressure loss inside the first tube 32 is reduced. When the pressure loss inside the first tube 32 is reduced, the flow rate of blood flowing through the circulation circuit increases. Therefore, in order to obtain a sufficient blood circulation amount, it is necessary to increase the inner diameter of the first tube 32.

On the other hand, when the wall thickness is substantially constant, increasing the inner diameters of the first tube 32 and the second tube 33 increases the outer diameters, which increases the burden on the patient when inserting the catheter 30 into the living body. It hinders minimally invasive procedures.

From the above viewpoints, the inner diameter of the first tube 32 may be, for example, 9 to 11 mm, and the inner diameter of the second tube 33 may be, for example, 4 to 8 mm. Moreover, the wall thickness of the 1st tube 32 and the 2nd tube 33 can be 0.4-0.5 mm, for example.

Further, as shown in FIGS. 2 to 4, it is preferable that the base end portion 32b of the first tube 32 has a tapered shape that gradually becomes thinner toward the base end side. As a result, the inner diameter of the base end of the first tube 32 is continuous with the inner diameter of the second tube 33 arranged on the base end side.

As shown in FIGS. 2 and 6, the first tube 32 includes a first reinforcing body 321 composed of wires W braided to intersect with each other, and a first resin provided so as to cover the first reinforcing body 321. And a layer 322. It is preferable that the tip portion 32a of the first tube 32 not have the first reinforcing body 321 exposed.

As shown in FIG. 2, the second tube 33 includes a second reinforcing body 331 made of wires W braided so as to intersect with each other, and a second resin layer 332 provided so as to cover the second reinforcing body 331. With.

In the present embodiment, the wire W is made of a known shape memory material such as a shape memory metal or a shape memory resin. As the shape memory metal, for example, titanium-based (Ni-Ti, Ti-Pd, Ti-Nb-Sn, etc.) or copper-based alloy can be used. Further, as the shape memory resin, for example, acrylic resin, transisoprene polymer, polynorbornene, styrene-butadiene copolymer, polyurethane can be used.

Since the wire W is made of a shape memory material, the contraction distance along the axial direction of the first tube 32 associated with the release of the gripped state of the tip portion 32a of the dilator 50 is such that the dilator 50 sandwiches the tip portion 32a. Thus, the extension distance along the axial direction of the first tube 32 due to the movement of the dilator 50 toward the distal end side is the same.

The wire diameter of the wire W is preferably 0.1 mm to 0.2 mm, for example. By setting the wire diameter of the wire W to 0.1 mm or more, the function as a reinforcing body for improving the strength can be suitably exerted. On the other hand, by setting the wire diameter of the wire W to 0.2 mm or less, the wall thickness of the first tube 32 can be set to 0.5 mm or less, and the inner diameter can be increased while reducing the outer diameter. It is possible to reduce the burden on the patient's body when inserting the catheter 30 and reduce the pressure loss. The cross section of the wire W is, for example, circular, but is not limited to this, and may be rectangular, square, oval, or the like.

The first resin layer 322 of the first tube 32 is made of a soft material having a lower hardness than the second resin layer 332 of the second tube 33. According to this configuration, the first tube 32 can be made softer than the second tube 33, and the elasticity can be enhanced.

The first and second resin layers 322 and 332 can be formed using vinyl chloride, silicon/polyethylene/nylon/urethane/polyurethane/fluorine resin/thermoplastic elastomer resin, or a composite material thereof.

The silicone material has high biocompatibility and the material itself is soft, so it has the feature that it does not damage blood vessels. The polyethylene material is soft and has a hardness that can withstand pressure. Moreover, polyethylene material has biocompatibility comparable to silicon material. Polyethylene material is harder than silicone and is easy to insert into a thin blood vessel. Further, the polyurethane material has a feature that it becomes soft after insertion. As a material for the first and second resin layers 322 and 332, a material that can be applied by utilizing the characteristics of these materials can be used.

Further, a hydrophilic coating may be applied to the polyurethane material. In this case, the surface of the tube is smooth, insertion of the blood vessel is easy, and the blood vessel wall is not easily damaged. Blood and proteins are unlikely to adhere, and it can be expected to prevent the formation of blood clots.

The method of forming the first tube 32 and the second tube 33 is not particularly limited, but they can be formed by, for example, dip coating (immersion method) or insert molding. Note that at least the outer surfaces of the reinforcing bodies 321 and 331 may be covered with the resin layers 322 and 332.

The connector 45 is a joint member that connects the first tube 32 and the second tube 33, as shown in FIGS. 2 to 5. The connector 45 is a tubular body as a whole and is made of, for example, hard plastic.

As shown in FIG. 7, the connector 45 has connecting portions 42 and 43 as reduced diameter portions at both ends of the tubular body. In the connector 45, by inserting the connecting portions 42 and 43 into the first and second tubes 32 and 33, the liquid passage 64 provided inside communicates with the first and second tubes 32 and 33. The connector 45 has a side hole 63 that is open to the side surface.

The side hole 63 functions as a blood removal hole. It is preferable to have a plurality of side holes 63 in the circumferential direction. In the present embodiment, the connector 45 is provided with four side holes 63 in the circumferential direction. As a result, even if one side hole 63 is adsorbed and blocked by the blood vessel wall due to blood removal, blood removal can be performed by the other side hole 63, so that stable blood circulation can be performed. ..

The clamping tube 34 is provided on the proximal end side of the second tube 33, as shown in FIGS. 2 to 4. A lumen through which the dilator 50 can be inserted is provided inside the clamp tube 34. The clamp tube 34 can be formed using the same material as the catheter tube 31.

As shown in FIGS. 2 to 4, the catheter connector 35 connects the second tube 33 and the clamp tube 34. A lumen through which the dilator 50 can be inserted is provided inside the catheter connector 35.

The lock connector 36 is connected to the proximal end side of the clamp tube 34, as shown in FIGS. A lumen through which the dilator 50 can be inserted is provided inside the lock connector 36. On the outer surface of the lock connector 36 on the proximal end side, a female screw portion 36A provided with a thread groove is provided.

Next, the configuration of the dilator 50 will be described.

The dilator 50 is an elongated body that extends in the axial direction and has relatively high rigidity. The dilator 50 is guided by the guide wire and inserted into the living body together with the catheter 30. The dilator 50 is removed from the catheter 30 by leaving the catheter 30 in the living body and then withdrawing the dilator 50 to the proximal end side.

The dilator 50 has a relatively high rigidity and is provided with a body that allows transmission of a pushing force to the distal end side by an operation at hand. Therefore, the dilator 50 plays a role of expanding a narrow blood vessel.

As shown in FIGS. 2 to 5, the dilator 50 includes a first dilator 51 extending in the axial direction and a second dilator 52 configured to be movable in the axial direction with respect to the first dilator 51. And.

The first dilator 51 includes a guide wire lumen 51a into which a guide wire (not shown) can be inserted.

The first dilator 51 has a barbed portion 511 having a barbed shape at its tip. The barbed portion 511 has a first tapered portion 512 which is provided on the inner peripheral surface of the base end and whose inner diameter increases toward the base end side. On the outer surface near the base end side of the first dilator 51, a male screw portion 51b provided with a screw thread is provided.

The second dilator 52 is arranged on the outer periphery of the first dilator 51. The second dilator 52 includes a lumen 52a into which the first dilator 51 can be inserted.

The second dilator 52 has a second taper portion 521 that is provided on the outer peripheral surface of the tip and has an outer diameter that decreases toward the tip side. As shown in FIGS. 4 and 5, the second tapered portion 521 can sandwich and hold the distal end portion 32 a of the first tube 32 together with the first tapered portion 512 of the first dilator 51.

The second dilator 52 is provided with a male screw portion 52b that is configured to be screwed into the female screw portion 36A of the lock connector 36 near the base end side. The dilator 50 is attachable to the catheter 30 by screwing the male screw portion 52b of the second dilator 52 into the female screw portion 36A of the lock connector 36.

The second dilator 52 is provided with a female screw portion 52c, which is configured to be screwed into the male screw portion 51b of the first dilator 51, on the base end side of the male screw portion 52b. The first dilator 51 is configured to be attachable to the second dilator 52 by screwing the male screw portion 51b of the first dilator 51 into the female screw portion 52c of the second dilator 52. .. In addition, by rotating the first dilator 51 while fixing the second dilator 52 with the first dilator 51 attached to the second dilator 52, the first dilator 51 is It moves in the axial direction with respect to the vibrator 52.

According to the first dilator 51 and the second dilator 52 thus configured, the first dilator 51 is inserted into the first taper portion 512 of the first dilator 51 while the first die 32 is inserted into the first dilator 51. By rotating the first dilator 51 so that the first taper portion 512 of the vibrator 51 and the second taper portion 521 of the second dilator come close to each other, the tip portion 32a is moved to the first dilator 51 and the second dilator 51. It is sandwiched between the vibrator 52. As a result, the tip portion 32a is gripped by the first dilator 51 and the second dilator 52. On the other hand, rotating the first dilator 51 so that the first taper portion 512 and the second taper portion 521 are separated from each other from the state in which the tip portion 32a is gripped by the first dilator 51 and the second dilator 52. Thus, the gripped state of the tip portion 32a by the first dilator 51 and the second dilator 52 is released.

<How to use the catheter>
Next, a method of using the catheter assembly 100 described above will be described with reference to FIGS. 3 and 8. FIG. 8(A) shows a state in which the tip portion 32a of the first tube 32 is gripped by the first dilator 51 and the second dilator 52, and FIG. 8(B) shows the first tube 32 in the axial direction. FIG. 8(C) shows a state in which the outer diameter is reduced and the outer diameter is reduced, and FIG. 8(C) shows a state in which the grip portion of the dilator 50 with respect to the distal end portion 32a is released. A state of being removed from 30 is shown.

First, as shown in FIG. 3, the operator screws the male screw portion 51b of the first dilator 51 into the female screw portion 52c of the second dilator 52 to integrate the first dilator 51 and the second dilator 52 together. It is inserted into the catheter 30 in the converted state. Specifically, the first tapered portion 512 of the first dilator 51 and the second tapered portion 521 of the second dilator 52 are inserted until they reach the vicinity of the tip end portion 32 a of the first tube 32. At this time, a gap G is formed between the first taper portion 512 and the second taper portion 521 by a predetermined distance.

Next, as shown in FIG. 8(A), the operator fixes the second dilator 52 while inserting the tip end portion 32 a of the first tube 32 into the first tapered portion 512 of the first dilator 51. While rotating the first dilator 51 counterclockwise when viewed from the base end side (see the arrow in FIG. 8(A)), the first dilator 51 is moved to the base end side, so that the distal end portion 32a is moved. , And is sandwiched between the first taper portion 512 and the second taper portion 521. As a result, the tip portion 32a is gripped by the first dilator 51 and the second dilator 52.

Next, the operator moves the first dilator 51 and the second dilator 52 to the tip side (see the arrow in FIG. 8B) as shown in FIG. 8B, and then the second dilator. The second dilator 52 is fixed to the catheter 30 by screwing the male screw portion 52b of 52 into the female screw portion 36A of the lock connector 36. As a result, the tip portion 32a held by the first dilator 51 and the second dilator 52 is pulled toward the tip side. As a result, the catheter 30 receives a force that extends in the axial direction, and the first tube 32 of the catheter 30, which has relatively high elasticity, extends in the axial direction. At this time, the first tube 32 extends in the axial direction, the outer diameter of the first tube 32 decreases, and becomes substantially the same as the outer diameter of the second tube 33.

Next, the operator inserts the catheter 30 with the first tube 32 extending in the axial direction and the outer diameter being reduced along a guide wire (not shown) that has been previously inserted into the target site in the living body. To insert. At this time, since the outer diameter of the first tube 32 is substantially the same as the outer diameter of the second tube 33, the catheter 30 can be inserted into the living body with minimal invasiveness, and the burden on the patient's body is reduced. Can be suppressed.

Further, the catheter 30 is inserted and left in the living body until the tip portion 32a is placed in the right atrium and the side hole 63 of the connector 45 is placed in the inferior vena cava. The first tube 32 is placed in the inferior vena cava, which is a relatively thick blood vessel, and the second tube 33 is placed in the femoral vein, which is a relatively thin blood vessel, with the tip portion 32a and the side hole 63 being placed in the blood removal target. Will be placed.

Next, as shown in FIG. 8(C), the operator rotates the first dilator 51 clockwise while viewing the first dilator 51 from the base end side while fixing the second dilator 52 (FIG. 8(C) arrow). (See) and move the first dilator 51 to the tip side. As a result, the tip portion 32a comes out of the first tapered portion 512, and the gripped state by the first dilator 51 and the second dilator 52 is released. As a result, the catheter 30 is released from the force that extends in the axial direction and contracts in the axial direction, and the inner diameter of the first tube 32 increases. Thereby, the pressure loss in the first tube 32 can be reduced and the required flow rate of the liquid can be secured.

Next, the operator removes the first dilator 51 and the second dilator 52 from the catheter 30, as shown in FIG. At this time, the dilator 50 and the guide wire are once pulled out to the position of the clamping tube 34 of the catheter 30 and clamped by forceps (not shown), and then completely removed from the catheter 30.

Next, the lock connector 36 of the catheter 30 is connected to the blood removal tube 11 of the extracorporeal circulation device of FIG. After confirming that the connection of the catheter on the blood supply side is completed, the forceps of the clamp tube 34 is released to start extracorporeal circulation.

When the extracorporeal circulation is completed, the catheter 30 is removed from the blood vessel, and the hemostasis is repaired by a surgical procedure as needed at the insertion site.

As described above, the method of using the catheter assembly 100 according to the present embodiment is summarized as follows: (i) an insertion step of inserting the first dilator and the second dilator into the catheter in an integrated state. , (Ii) a grasping step of sandwiching and grasping the distal end portion of the catheter tube with the first dilator and the second dilator, and (iii) moving the first dilator and the second dilator to the distal end side to form the catheter tube. In an axial direction, (iv) an insertion step of inserting a catheter in a state in which the catheter tube is axially expanded into a living body, and (v) the first dilator with respect to the second dilator. A releasing step of moving the first dilator and the second dilator relative to each other in the axial direction to release the gripped state of the tip portions of the first dilator and the second dilator; and (vi) a removing step of withdrawing the first dilator and the second dilator. Have.

As described above, the catheter assembly 100 according to the present embodiment is the catheter assembly 100 that includes the catheter 30 for passing blood and the dilator 50 that is inserted into the catheter 30. The catheter 30 has a catheter tube 31 that has a distal end portion 32a that is open at the distal end in the insertion direction and that extends in the axial direction. The dilator 50 includes a first dilator 51 extending in the axial direction and a second dilator 52 configured to be movable relative to the first dilator 51 in the axial direction. The tip portion 32a is gripped by being sandwiched between the first dilator 51 and the second dilator 52, and is accompanied by the relative movement of the first dilator 51 in the axial direction with respect to the second dilator 52. The first dilator 51 and the second dilator 52 are released from the gripped state. The catheter tube 31 is extended in the axial direction by the first dilator 51 and the second dilator 52 moving toward the distal end side in the insertion direction with the distal end portion 32a being gripped, and the outer diameter is reduced. When the state is released, the outer diameter is expanded by contracting in the axial direction. According to the catheter assembly 100 configured in this way, the first dilator 51 and the second dilator 52 move toward the distal end side in the insertion direction while holding the distal end portion 32a, and the catheter tube 31 is axially moved. The outer diameter can be reduced by stretching in the direction. Therefore, by inserting the catheter 30 into the living body in a state where the outer diameter of the catheter tube 31 is small, the burden on the body of the patient can be suppressed. In addition, after the catheter 30 is left in the living body, the first dilator 51 is moved relative to the second dilator 52 in the axial direction, whereby the tips of the first dilator 51 and the second dilator 52 are moved. The gripped state of the portion 32a is released. As a result, the catheter tube 31 contracts in the axial direction and the outer diameter increases. Therefore, the pressure loss in the catheter tube 31 is reduced, and the required flow rate of the liquid can be secured. From the above, it is possible to suppress the burden on the patient's body, reduce the pressure loss of the liquid circulating in the circulation circuit, and secure the required flow rate of the liquid.

The tip portion 32a has the same outer diameter as the maximum outer diameter of the first tube 32 when the gripped state is released. Therefore, the pressure loss of the liquid can be further reduced as compared with the configuration in which the tip is provided at the tip of the first tube.

Further, as the first dilator 51 rotates with respect to the second dilator 52, the first dilator 51 moves axially with respect to the second dilator 52. Therefore, the first dilator 51 can be moved in the axial direction with respect to the second dilator 52 by an easy operation at hand.

Further, the first dilator 51 has a barbed portion 511 having a barbed shape at the tip thereof. The second dilator 52 has a second taper portion 521 provided on the outer peripheral surface of the tip and having an outer diameter that decreases toward the tip side, and the tip portion 32a includes the first taper portion 512 and the second taper portion 512. It is configured such that it can be sandwiched between it and the taper portion 521. Therefore, the first taper portion 512 and the second taper portion 521 can sandwich and hold the tip portion 32a in a suitable manner.

Further, the catheter tube 31 has reinforcing bodies 321 and 331 made of wires W braided so as to intersect each other, and the wires W are made of a shape memory material. Therefore, when the gripped state of the distal end portion 32a of the dilator 50 is released, the catheter tube 31 contracts in the axial direction and the outer diameter expands, so that the catheter tube 31 preferably returns to the original shape. Therefore, the pressure loss can be reduced more favorably.

Further, the catheter tube 31 has a first tube 32 and a second tube 33 provided on the proximal end side in the insertion direction of the first tube 32, and the first tube 32 is thicker than the second tube 33. It has an inner diameter and is configured to have higher elasticity than the second tube 33. Therefore, the first dilator 51 and the second dilator 52 move toward the distal end side while gripping the distal end portion 32a, so that the first tube 32 having high elasticity expands in the axial direction. The outer diameter becomes smaller. As a result, the catheter 30 can be inserted into the living body in a minimally invasive manner. When the gripped state of the tip portion 32a of the dilator 50 is released, the first tube 32 contracts and the inner diameter of the first tube 32 increases. As a result, the pressure loss inside the first tube 32 can be reduced.

In addition, the catheter assembly 100 further includes a connector 45 that connects the first tube 32 and the second tube 33 and that has a side hole 63 that opens to the side surface. Therefore, blood removal can be performed via the tip portion 32a and the connector 45. Therefore, blood circulation can be performed stably.

Further, as described above, according to the catheter 30 and the dilator 50 according to the present embodiment, the burden on the body of the patient is suppressed, the pressure loss of the liquid circulating in the circulation circuit is reduced, and the required liquid flow rate. Can be secured.

<Second Embodiment>
Next, a percutaneous catheter assembly (hereinafter, referred to as “catheter assembly”) 200 according to the second embodiment of the present invention will be described with reference to FIGS. 9 and 10. 9 and 10 are diagrams for explaining the configuration of the catheter assembly 200 according to the second embodiment.

As shown in FIG. 9, a catheter assembly 200 according to the second embodiment includes a percutaneous catheter (hereinafter, referred to as “catheter”) 60 for passing blood, a dilator 50 inserted through the catheter 60, Have. Since the configuration of the dilator 50 is the same as that of the first embodiment, the description will be omitted. The catheter 60 will be described below.

This catheter 60 is a so-called double-lumen catheter, and is capable of both blood supply and blood removal at the same time. Therefore, in the present embodiment, the extracorporeal circulation device of FIG. 1 does not use two catheters of the vein side catheter (blood removal catheter) 5 and the arterial side catheter (blood supply catheter) 6 and one catheter is used. The procedure is performed using only the catheter 60.

In the catheter 60 according to the present embodiment, as shown in FIGS. 9 and 10, the third tube 161 including the first lumen 61 communicating with the blood supply side hole 163 of the connector 145 has the inner lumen of the second tube 133. The catheter 30 according to the first embodiment differs from the catheter 30 in that it has a double-tube structure arranged in the.

According to the catheter 60, the pump of the extracorporeal circulator is operated to remove blood from the patient's vein (caval vein), and the oxygenation of the blood is performed by exchanging gas in the blood with the artificial lung. The artificial lung extracorporeal blood circulation of the venous-venous system (Veno-Venous, VV) for returning the blood vessel to the patient's vein (caval vein) again can be performed.

Hereinafter, each component of the catheter 60 will be described. It should be noted that the description of the portions common to the first embodiment will be omitted, and only the features unique to the second embodiment will be described. Further, the same parts as those of the above-described first embodiment will be described with the same reference numerals, and the duplicated description will be omitted.

As shown in FIGS. 9 and 10, the catheter 60 has a first tube 32, a second tube 133, a connector 145 connecting the first tube 32 and the second tube 133, and a lumen of the second tube 133. The 3rd tube 161 arrange|positioned is included. The configuration of the first tube 32 is the same as the configuration of the catheter 30 of the first embodiment, and thus the description thereof will be omitted.

As shown in FIG. 10, the catheter 60 has a first lumen 61 that functions as a blood supply path and a second lumen 62 that functions as a blood removal path.

The first lumen 61 is formed in the inner cavity of the third tube 161. The second lumen 62 is formed in the inner cavities of the first tube 32, the second tube 133 and the connector 145, and penetrates from the distal end to the proximal end.

The connector 145 includes a blood supply side hole 163 that communicates with the first lumen 61 that is a blood supply path.

The second tube 133 includes a blood removal side hole 164 that communicates with the second lumen 62 that is a blood removal path.

The blood supply side hole 163 and the blood removal side hole 164 are formed in an elliptical shape.

The third tube 161 is inserted into the second lumen 62 from the base end side of the second tube 133 and is connected to the blood supply side hole 163.

The blood supply side hole 163 is arranged for a blood supply target in the living body, and the blood oxygenated by the artificial lung is delivered into the living body through the blood supply side hole 163.

The blood removal side holes 164 included in the distal end portion 32a of the first tube 32 and the second tube 133 are arranged for different blood removal targets in the living body, and are configured to perform blood removal efficiently. Further, even if the distal end portion 32a or the blood removal side hole 164 is adsorbed and blocked by the blood vessel wall, blood can be removed from the hole that is not closed, so that extracorporeal circulation is stably performed. be able to.

In the present embodiment, the catheter 60 is inserted from the internal jugular vein of the neck, and the tip is placed in the inferior vena cava via the superior vena cava and the right atrium. The blood supply target is the right atrium, and the blood removal targets are the upper vena cava and the lower vena cava.

The catheter 60 is used in the living body so that the distal end portion 32a is located in the inferior vena cava and the blood removal side hole 164 of the second tube 133 is located in the internal jugular vein in a state where the first tube 32 is extended in the axial direction. Is inserted and detained.

Similar to the first embodiment, the first tube 32 is configured to have an inner diameter larger than that of the second tube 133. The first tube 32 is placed in the inferior vena cava, which is a relatively thick blood vessel, and the second tube 133 is a relatively thin blood vessel, with the tip portion 32a and the blood removal side hole 164 being placed in the blood removal target. Placed in the femoral vein.

As shown in FIG. 10, the lock connector 136 is provided in parallel with the first lock connector 137 that communicates with the first lumen 61, and the second lock connector that is provided in parallel with the first lock connector 137 and that communicates with the second lumen 62. And 138. The lock connector 136 is a Y-shaped Y connector formed by branching the first lock connector 137 from the second lock connector 138.

The first lock connector 137 is connected to the base end of the third tube 161. The second lock connector 138 is coaxially connected to the base end portion of the second tube 133. A blood supply tube (blood supply line) is connected to the first lock connector 137, and a blood removal tube (blood removal line) is connected to the second lock connector 138.

The first tube 32 exhibits the same function as that of the first embodiment, and has the same action and effect.

As described above, according to the catheter 60 according to the present embodiment, one catheter can fulfill both functions of blood removal and blood supply.

The catheter according to the present invention has been described above through the embodiments. However, the present invention is not limited to the configurations described in the embodiments and the modifications, and may be appropriately changed based on the description of the claims. It is possible.

For example, in the above-described first embodiment, the first resin layer 322 of the first tube 32 is made of a soft material having a hardness lower than that of the second resin layer 332 of the second tube 33. Compared with, the first tube 32 was softened to enhance the elasticity. However, instead of or in addition to this, the first reinforcing body 321 is braided so as to be sparser than the second reinforcing body 331, so that the first tube 32 is compared with the second tube 33. May be softened to enhance elasticity. Further, by making the wire diameter of the wire W forming the first reinforcing body 321 of the first tube 32 smaller than the wire diameter of the wire W forming the second reinforcing body 331 of the second tube 33, the second tube As compared with 33, the first tube 32 may be softened to enhance elasticity.

In addition, the material forming the wire W is not limited to the configuration in which the material is a shape memory material as long as the material has a restoring force to be deformed to return to the original shape and has a function of reinforcing the resin layer. It can be made of a known elastic material.

In addition, in the above-described first embodiment, the catheter 30 is used as the vein side catheter (blood removal catheter) 5 in FIG. However, the catheter 30 may be used as the artery side catheter (blood supply catheter) 6 of FIG.

Further, in the above-described second embodiment, the tip portion 32a and the blood removal side hole 164 are used for blood removal, and the blood supply side hole 163 is used for blood supply. However, the tip portion 32a and the side hole 164 may be used for blood supply, and the side hole 163 may be used for blood removal.

Further, in the above-described first embodiment and second embodiment, the first tube 32 is provided with the first resin layer 322, but it may be configured without the first resin layer.

Further, although the catheter 30 has the second tube 33 in the above-described first embodiment, the catheter 30 may have a configuration without the second tube.

Further, in the above-described first embodiment, the catheter 30 has the connector 45 including the side hole 63 that opens to the side surface, but the connector 45 may not be provided.

Further, in the above-described first embodiment, the distal end portion 32a has the same outer diameter as the maximum outer diameter of the catheter tube 31 when the gripped state by the first dilator 51 and the second dilator 52 is released. Composed. However, the present invention is not limited to this, and the distal end portion may have a configuration that is larger or smaller than the maximum outer diameter of the catheter tube 31 when the gripped state by the first dilator 51 and the second dilator 52 is released. ..

Further, in the above-described first embodiment, the tip portion 32a is configured to be sandwiched between the first taper portion 512 and the second taper portion 521. However, the tip portion 32a is not particularly limited as long as it is configured to be sandwiched and held by the first dilator 51 and the second dilator 52.

In addition, in the above-described first embodiment, the first dilator 51 is rotated with respect to the second dilator 52 to move the first dilator 51 in the axial direction with respect to the second dilator 52. However, the first dilator 51 may be moved in the axial direction with respect to the second dilator 52 by operating the first dilator 51 to move straight in the axial direction with respect to the second dilator 52.

Further, in the above-described first embodiment, the first dilator 51 is rotated with respect to the second dilator 52, and the first dilator 51 is moved in the axial direction with respect to the second dilator 52. However, the second dilator 52 may be rotated with respect to the first dilator 51 to move the second dilator 52 in the axial direction with respect to the first dilator 51.

This application is based on Japanese Patent Application No. 2016-113691 filed on Jun. 7, 2016, the disclosure content of which is incorporated by reference in its entirety.

100, 200 catheter assembly (percutaneous catheter assembly),
30,60 catheter (percutaneous catheter),
31 catheter tube,
32 first tube,
32a tip,
321 first reinforcement,
33, 133 second tube,
331 second reinforcement,
45, 145 connectors,
50 dilator,
51 First Dilator,
511 Arrowhead,
512 first tapered portion,
52 Second dilator,
521 second taper portion,
63 side hole,
W wire.

Claims (8)

A percutaneous catheter assembly having a percutaneous catheter for passing blood, and a dilator inserted into the percutaneous catheter,
The percutaneous catheter has a catheter tube extending in the axial direction with a distal end portion opened at the distal end in the insertion direction,
The dilator has a first dilator extending in the axial direction and a second dilator configured to be relatively movable in the axial direction with respect to the first dilator,
The tip portion is gripped by being sandwiched between the first dilator and the second dilator, and at the time of relative movement of the first dilator with respect to the second dilator in the axial direction. Accordingly, the holding state by the first dilator and the second dilator is released,
The catheter tube is extended in the axial direction and reduced in outer diameter by moving toward the distal end side in the insertion direction with the first dilator and the second dilator holding the distal end portion, A percutaneous catheter assembly having an outer diameter expanded by contracting in the axial direction when the gripped state is released. The percutaneous catheter assembly according to claim 1, wherein the distal end portion has the same outer diameter as the maximum outer diameter of the catheter tube when the gripped state is released. The relative movement in the axial direction of the first dilator with respect to the second dilator is performed in association with the relative rotation operation of the first dilator with respect to the second dilator. The percutaneous catheter assembly according to item 2. The first dilator has a barbed portion at the tip,
The barbed portion has a first taper portion which is provided on the inner peripheral surface of the base end and whose inner diameter increases toward the base end side,
The second dilator has a second taper portion that is provided on the outer peripheral surface of the tip and has an outer diameter that decreases toward the tip side.
The percutaneous catheter assembly according to any one of claims 1 to 3, wherein the distal end portion is configured to be sandwiched between the first tapered portion and the second tapered portion. The catheter tube has a reinforcement made of wires braided to intersect,
The percutaneous catheter assembly according to claim 1, wherein the wire is made of a shape memory material. The catheter tube is
The first tube,
A second tube provided on the base end side in the insertion direction of the first tube,
The percutaneous catheter assembly according to any one of claims 1 to 5, wherein the first tube has an inner diameter larger than that of the second tube and is configured to have higher elasticity than the second tube. The percutaneous catheter assembly according to claim 6, further comprising a connector that connects the first tube and the second tube and that has a side hole that is open to a side surface. A dilator that is inserted through a percutaneous catheter,
A first dilator extending in the axial direction,
A second dilator configured to be movable relative to the first dilator in the axial direction,
The first dilator expands the catheter tube in the axial direction by moving together with the second dilator to the distal end side while sandwiching and gripping the distal end portion opened at the distal end in the insertion direction of the catheter tube. To reduce the outer diameter,
As the first dilator moves relative to the second dilator in the axial direction, the gripping state of the distal end portion is released, whereby the catheter tube contracts in the axial direction and the outer diameter increases. Diameter dilator.