JP7671160B2 - catheter - Google Patents

Description

The present invention relates to a catheter.

As the population ages, the number of patients with heart failure is increasing. Conventionally, surgical transplantation has been used to treat heart failure, but in recent years, development of regenerative medicine techniques that do not involve transplantation has progressed. For example, Patent Document 1 discloses a technique in which myocardial tissue cells are cultured to create a myocardial-like cell sheet, which is then attached to the heart. However, it is not easy to maintain such a cell sheet attached to an organ for a long period of time. This is particularly true when it comes to attaching a myocardial-like cell sheet to the heart, which is constantly beating.

In response to this, Patent Document 2 discloses a drug injection therapy in which a drug solution containing bFGF (basic fibroblast growth factor), VEGF (vascular endothelial growth factor), HGF (hepatocyte growth factor), etc., which are genes that promote angiogenesis, is injected from inside the blood vessels to the myocardium, and a drug injection catheter that can be used in such a drug injection therapy. Patent Document 3 also discloses a vascular drug injection catheter that can be used in drug injection therapy.

Patent No. 5572138 JP 2001-104487 A Patent No. 4656690

However, the drug injection catheter described in Patent Document 2 has a puncture needle protruding from the tip of the catheter for injecting drug solution, so when injecting drug solution into the myocardial wall, the catheter needs to reach the right ventricle from the vena cava. However, it is not easy to fix the tip of the catheter inside the ventricle, and there are also issues with the puncture site (drug solution injection site) being limited within the ventricle.

In this regard, the vascular drug injection catheter described in Patent Document 3 can project a puncture needle from the side of the catheter, so that the procedure can be completed within the coronary artery without the catheter reaching the ventricle, similar to the conventional percutaneous coronary intervention (PCI) procedure. In addition, the puncture site (drug injection site) can be freely selected by moving the catheter within the blood vessel. However, the vascular drug injection catheter described in Patent Document 3 expands the expansion section within the blood vessel to obtain the force (puncture force) to reach the puncture needle from within the blood vessel to the myocardial wall, which may cause ischemia. Patent Document 1 does not take drug injection therapy into consideration at all.

These issues are not limited to cases where a medicinal liquid is injected into the myocardial wall, but are common to catheters inserted into various organs within the human body, such as the blood vessels, lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, in order to inject medicinal liquid into biological tissue. These issues are not limited to cases where a medicinal liquid is injected into biological tissue for treatment, but are common to cases where a medicinal liquid is injected into biological tissue for diagnosis.

The present invention has been made to solve at least some of the above problems, and aims to provide a catheter for injecting medicinal liquid that allows the injection of medicinal liquid into target tissue from within a blood vessel and that can impart a puncture force to a puncture needle without causing ischemia.

The present invention has been made to solve at least some of the above problems, and can be realized in the following form.

(1) According to one aspect of the present invention, a catheter having a shaft is provided. In this catheter, the shaft includes a first lumen extending in the longitudinal direction of the shaft, a second lumen arranged in line with the first lumen, a third lumen arranged in line with the first lumen and the second lumen, a first opening formed at the tip of the shaft and communicating with the first lumen, a second opening formed on the side of the shaft on the base end side of the first opening and communicating with the second lumen, and a third opening formed on the side of the shaft on the base end side of the first opening and communicating with the third lumen, and in a cross section of the shaft, the first lumen is arranged in the center of the shaft, and the second lumen and the third lumen are arranged on opposite sides of the first lumen.

According to this configuration, the shaft has a first lumen extending to the first opening at the tip, a second lumen extending to the second opening on the side, and a third lumen extending to the third opening on the side. Therefore, the first lumen can be used as a guidewire lumen for inserting a delivery guidewire, the second lumen can be used as a needle lumen for a puncture needle, and the third lumen can be used as a backup lumen for inserting a backup device (e.g., a guidewire or a catheter) for applying a puncture force to the puncture needle. That is, according to this configuration, the tip of the puncture needle can be protruded from the second opening on the side of the shaft to puncture the target tissue, so that a drug solution can be injected into the target tissue from within the blood vessel. Therefore, as with the conventional percutaneous coronary intervention (PCI) procedure, the procedure can be completed within the coronary artery without the catheter reaching the ventricle, and the puncture site (drug solution injection site) can be freely selected by moving the catheter within the blood vessel. In addition, according to this configuration, since a puncture force can be applied to the puncture needle using a backup device such as a guidewire or a catheter, compared to the conventional configuration (a configuration in which a puncture force is applied to the puncture needle by expanding an expansion part in a blood vessel), a puncture force can be applied to the puncture needle without ischemia. Furthermore, according to this configuration, since the first lumen functioning as a guidewire lumen is arranged in the center of the shaft in the cross section of the shaft, the operability when delivering the catheter to the target tissue (the biological tissue into which the drug solution is intended to be injected) can be improved. In addition, when the tip of the puncture needle is protruded from the second opening to puncture the target tissue with the puncture needle inserted into the second lumen, the guidewire inserted into the first lumen and the backup device inserted into the third lumen receive a reaction force against the puncture. In this regard, according to this configuration, the second lumen through which the puncture needle is inserted and the third lumen through which the backup device is inserted are arranged on opposite sides of the first lumen in the cross section of the shaft. This prevents the reaction force against the puncture from being dispersed in different directions, and prevents the catheter from rotating during the puncture. As a result, the accuracy of the puncture by the puncture needle can be improved.

(2) In the catheter of the above form, the third opening is located near the second opening in the longitudinal direction of the shaft, and when a first line segment connecting the center of the shaft and a center point of the second opening and a second line segment connecting the center of the shaft and the center point of the third opening are viewed in the longitudinal direction of the shaft, the angle formed by the first line segment and the second line segment may be approximately 180 degrees.
According to this configuration, the second opening and the third opening are disposed at positions spaced apart by approximately 180 degrees in the circumferential direction of the shaft. Therefore, the puncture needle protruding from the second opening can be supported by the backup device protruding from the third opening, which is disposed at a position spaced apart by approximately 180 degrees. In other words, it is possible to dispose the backup device for receiving the reaction force and supporting the puncture needle in the direction in which the reaction force due to the puncture is generated. As a result, it is possible to prevent the catheter from moving back and forth (in the longitudinal direction) or from rotating in the circumferential direction due to the reaction force due to the puncture.

(3) In the catheter of the above aspect, the hardness of the inner circumferential wall forming the second lumen may be higher than the hardness of the inner circumferential wall forming the first lumen and the inner circumferential wall forming the third lumen.
The puncture needle is configured with a sharp tip for the purpose of puncturing the target tissue. With this configuration, the hardness of the inner wall forming the second lumen is higher than the hardness of the inner wall forming the first lumen and the inner wall forming the third lumen. Therefore, even if the sharp tip of the puncture needle hits the inner wall of the second lumen when the puncture needle is delivered toward the tip side in the second lumen and the tip of the puncture needle protrudes from the second opening, damage to the inner wall can be suppressed. As a result, the durability of the catheter can be improved.

(4) In the catheter of the above embodiment, the tip side of the second lumen is curved toward the second opening, and in a longitudinal cross-section of the shaft including the curved portion, the acute angle formed by the central axis of the second lumen on the base end side of the curved portion and the central axis of the curved portion may be greater than or equal to 30 degrees and less than 70 degrees.
With this configuration, the acute angle formed by the central axis of the second lumen on the base end side of the curved portion and the central axis of the curved portion is greater than or equal to 30 degrees and less than 70 degrees, so that the puncture angle of the puncture needle protruding from the second lumen can be made greater than or equal to 30 degrees and less than 70 degrees, which is suitable for puncture.

(5) In the catheter of the above form, the shaft may further include a fourth lumen arranged in parallel with the first lumen, the second lumen, and the third lumen, and a fourth opening formed on a side of the shaft base end side of the first opening and communicating with the fourth lumen, wherein the fourth opening is arranged at a different position from the third opening in the longitudinal direction of the shaft, and the fourth opening is arranged at the same position as the third opening in the circumferential direction of the shaft.
According to this configuration, the shaft further has a fourth lumen extending to the fourth opening on the side surface, so that a second backup device other than the backup device inserted through the third lumen can be used in combination. As a result, a stronger puncture force can be applied to the puncture needle. In addition, the fourth opening is disposed at a different position from the third opening in the longitudinal direction of the shaft, and at the same position as the third opening in the circumferential direction of the shaft, so that the backup device and the second backup device can support the catheter and the puncture needle from different positions in the longitudinal direction.

(6) In the catheter of the above form, the shaft may further include a fourth lumen arranged in parallel with the first lumen, the second lumen, and the third lumen, and a fourth opening formed on a side of the shaft base end side of the first opening and communicating with the fourth lumen, wherein the fourth opening is arranged at the same position as the third opening in the longitudinal direction of the shaft, and the fourth opening is arranged at a different position from the third opening in the circumferential direction of the shaft.
According to this configuration, the shaft further has a fourth lumen extending to the fourth opening on the side surface, so that a second backup device other than the backup device inserted through the third lumen can be used in combination. As a result, a stronger puncture force can be applied to the puncture needle. In addition, the fourth opening is disposed at the same position as the third opening in the longitudinal direction of the shaft, and at a different position from the third opening in the circumferential direction of the shaft, so that the backup device and the second backup device can support the catheter and the puncture needle from different positions in the circumferential direction.

(7) In the catheter of the above aspect, an opening area of the second opening may be larger than an area of the second lumen in a cross section of the shaft.
According to this configuration, the opening area of the second opening is larger than the area of the second lumen in the cross section of the shaft, making it easier to protrude the puncture needle from the second opening.

(8) In the catheter of the above aspect, the shaft may further include a radiopaque annular first marker portion provided on a side surface of the shaft in the vicinity of the second opening.
According to this configuration, the shaft further includes a first annular marker portion having radiopaque properties and provided near the second opening, so that the surgeon can easily puncture the target tissue with the puncture needle protruding from the second opening by adjusting the front-to-rear position of the catheter so that the first marker portion is located near the target tissue.

(9) In the catheter of the above form, the shaft may further include a second marker portion having radiopacity and provided on a side of the shaft near the second opening, the second marker portion allowing the position of the second opening in the circumferential direction to be recognized based on the shape of the second marker portion when viewed from any direction.
According to this configuration, the shaft further includes a radiopaque second marker portion provided near the second opening, the second marker portion being capable of recognizing the position of the second opening in the circumferential direction based on the shape of the second marker portion when viewed from any direction. Therefore, the surgeon can easily puncture the target tissue with the puncture needle protruding from the second opening by adjusting the circumferential position of the catheter (rotating the catheter) so that the second marker portion is located on the side of the blood vessel wall facing the heart.

(10) In the catheter of the above form, the shaft further comprises an outer shaft, a first inner shaft having the first lumen on its inside, a second inner shaft having the second lumen on its inside, and a third inner shaft having the third lumen on its inside, wherein the first inner shaft, the second inner shaft, and the third inner shaft each extend further toward the base end than the base end of the outer shaft when inserted inside the outer shaft, and at least their base ends are fixed to the outer shaft, and an operating unit that can be rotated is further fixed to the base end of the outer shaft.
According to this configuration, by performing a rotation operation on the operation unit fixed to the base end of the outer shaft, the outer shaft can be rotated by the rotation applied to the operation unit, and the first, second, and third inner shafts fixed to the outer shaft can be rotated. Therefore, the catheter can be easily rotated to adjust the circumferential position of the catheter in the blood vessel, and usability can be improved.

The present invention can be realized in various forms, such as a catheter for injecting a drug solution, a shaft for a catheter for injecting a drug solution, a system including a catheter for injecting a drug solution and a device such as a puncture needle, and a method for manufacturing these.

FIG. 1 is an explanatory diagram illustrating a configuration of a catheter. FIG. 2 is an enlarged cross-sectional view of a portion of the distal end of the catheter. 3 is an explanatory diagram illustrating a cross-sectional configuration taken along line AA in FIG. 2. 3 is an explanatory diagram illustrating the configuration of a catheter as viewed from direction B in FIG. 2 . FIG. FIG. 1 is a diagram showing an example of a drug solution injection therapy using a catheter. FIG. 13 is a diagram showing another example of drug solution injection therapy using a catheter. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter of a second embodiment. FIG. 8 is an explanatory diagram illustrating a cross-sectional configuration taken along line CC in FIG. 7. FIG. 1 is a diagram showing an example of a drug solution injection therapy using a catheter. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter of a third embodiment. FIG. FIG. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter according to a fourth embodiment. 12 is an explanatory diagram illustrating a cross-sectional configuration taken along line DD in FIG. 11. FIG. 13 is an enlarged cross-sectional view of a portion of the distal end side of a catheter according to a fifth embodiment. FIG. 13 is an enlarged cross-sectional view of a portion of the tip side of a catheter of a sixth embodiment. FIG. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter according to a seventh embodiment. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter of an eighth embodiment. FIG. FIG. 13 is an explanatory diagram illustrating the configuration of the tip side of a catheter according to the ninth embodiment. FIG. 19 is an explanatory diagram illustrating the cross-sectional configuration of a catheter according to a tenth embodiment. 19 is an explanatory diagram illustrating the configuration of the base end side of a catheter according to an eleventh embodiment. FIG. FIG. 23 is an explanatory diagram illustrating the configuration of the base end side of a catheter according to a twelfth embodiment. 21 is an explanatory diagram illustrating a cross-sectional configuration taken along line F1-F1 in FIG. 20. 21 is an explanatory diagram illustrating a cross-sectional configuration taken along line F2-F2 in FIG. 20.

First Embodiment
FIG. 1 is an explanatory diagram illustrating the configuration of a catheter 1. The catheter 1 is a catheter for injecting a drug solution used for performing a drug solution injection treatment for heart failure, for example, by injecting a drug solution containing bFGF (basic fibroblast growth factor), VEGF (vascular endothelial growth factor), HGF (hepatocyte growth factor), etc. The catheter 1 is capable of completing a drug solution injection treatment procedure in a coronary artery without reaching the ventricle of the heart, similar to the conventional percutaneous coronary intervention (PCI) procedure, by projecting a puncture needle from the side of the catheter 1 and reaching the puncture needle from inside a blood vessel to a myocardial wall. The catheter 1 includes a shaft 10, a distal tip 71, and a connector 90. In FIG. 1, a first lumen 20L, a second lumen 30L, and a third lumen 40L formed in the shaft 10 are indicated by dashed lines.

In FIG. 1, the axis passing through the center of the catheter 1 is represented by the axis O (dotted line). For the sake of convenience, FIG. 1 includes parts in which the relative ratio of the sizes of the components is depicted differently from the actual ratio. Also, some of the components are depicted in an exaggerated manner. FIG. 1 also illustrates mutually orthogonal XYZ axes. The X axis corresponds to the longitudinal direction of the catheter 1, the Y axis corresponds to the height direction of the catheter 1, and the Z axis corresponds to the width direction of the catheter 1. The left side of FIG. 1 (-X axis direction) is called the "tip side" of the catheter 1 and each component, and the right side of FIG. 1 (+X axis direction) is called the "base side" of the catheter 1 and each component. In addition, of the two ends of the catheter 1 and each component in the longitudinal direction (X axis direction), the one end located on the tip side is called the "tip" and the other end located on the base side is called the "base end". In addition, the tip and its vicinity are called the "tip portion", and the base end and its vicinity are called the "base end portion". The tip end is inserted into the living body, and the base end is operated by a surgeon such as a doctor. These points are the same in Figure 1 and subsequent figures.

Figure 2 is an enlarged cross-sectional view of a portion of the tip side of the catheter 1. Figure 3 is an explanatory diagram illustrating the cross-sectional configuration along line A-A in Figure 2. Figure 4 is an explanatory diagram illustrating the configuration of the catheter 1 as viewed from direction B in Figure 2. Note that an explanatory diagram of the openings of the catheter 1 is shown in a speech bubble in the upper part of Figure 4. The lower part of Figure 4 shows the configuration of the catheter 1, and also shows in dashed lines the third tip opening 41, which is not normally visible from the +Y axis direction. The configuration of the catheter 1 will be explained below using Figures 1 to 4.

As shown in Figures 2 and 3, the shaft 10 of the catheter 1 includes an outer shaft 11, a sealing member 12, a first inner shaft 23, a second inner shaft 33, a third inner shaft 43, a first marker portion 72, and a second marker portion 73.

The outer shaft 11, the first inner shaft 23, the second inner shaft 33, and the third inner shaft 43 are all hollow and elongated, and have a substantially circular cross section. The first inner shaft 23, the second inner shaft 33, and the third inner shaft 43 are each inserted into the lumen of the outer shaft 11, and extend substantially parallel to each other along the longitudinal direction (X-axis direction) of the outer shaft 11. In the cross section shown in FIG. 3, the first inner shaft 23 is disposed in the center of the lumen of the outer shaft 11. In this embodiment, "center" means the center and the vicinity of the center. In addition, in the cross section shown in FIG. 3, the second inner shaft 33 and the third inner shaft 43 are disposed on opposite sides of the first inner shaft 23 in the lumen of the outer shaft 11. In the example of FIG. 3, the second inner shaft 33 is disposed in the +Y-axis direction with the first inner shaft 23 as a reference, and the third inner shaft 43 is disposed in the -Y-axis direction with the first inner shaft 23 as a reference.

As shown in FIG. 1, the first inner shaft 23 extends linearly from the tip to the base. The tip of the first inner shaft 23 is connected to the outside through a tip first opening 21 formed on the tip surface of the shaft 10. The base end of the first inner shaft 23 is connected to the outside through a base first opening 22 formed on the first branch (branch extending in the +X-axis direction) of the connector 90. The second inner shaft 33 has a tip side portion and a base side portion curved in the +Y-axis direction. The tip of the second inner shaft 33 is connected to the outside through a tip second opening 31 formed on the side surface of the shaft 10 in the +Y-axis direction. The base end of the second inner shaft 33 is connected to the outside through a base second opening 32 formed on the second branch (branch extending in the +Y-axis direction) of the connector 90. The third inner shaft 43 has a tip side portion and a base side portion curved in the -Y-axis direction. The tip of the third inner shaft 43 is connected to the outside through a tip third opening 41 formed on the side surface of the shaft 10 in the -Y axis direction. The base end of the third inner shaft 43 is connected to the outside through a base third opening 42 formed in the third branch (the branch in the -Y axis direction) of the connector 90.

The sealing member 12 seals (fixes) the first inner shaft 23, the second inner shaft 33, and the third inner shaft 43 within the outer shaft 11. The sealing member 12 is disposed inside the outer shaft 11 and outside the first inner shaft 23, the second inner shaft 33, and the third inner shaft 43.

The first lumen 20L formed inside the first inner shaft 23 functions as a "guidewire lumen" through which a delivery guidewire is inserted into the catheter 1. The second lumen 30L formed inside the second inner shaft 33 functions as a "needle lumen" through which a puncture needle is inserted into the catheter 1. The third lumen 40L formed inside the third inner shaft 43 functions as a "backup lumen" through which a backup device is inserted into the catheter 1. Here, the backup device refers to a device for applying a puncture force to the puncture needle, and can be, for example, a guidewire or a catheter.

That is, in the catheter 1 of this embodiment, the shaft 10 has a first lumen 20L, a second lumen 30L, and a third lumen 40L arranged side by side (FIG. 2). In the cross section of the shaft 10 shown in FIG. 3, the first lumen 20L is arranged in the center of the shaft 10. In the cross section of the shaft 10 shown in FIG. 3, the second lumen 30L and the third lumen 40L are arranged on opposite sides of the first lumen 20L. In addition, a tip first opening 21 communicating with the first lumen 20L is formed at the tip of the shaft 10. Furthermore, a tip second opening 31 communicating with the second lumen 30L and a tip third opening 41 communicating with the third lumen 40L are formed on the side of the shaft 10 (FIG. 2). The tip first opening 21 corresponds to the "first opening", the tip second opening 31 corresponds to the "second opening", and the tip third opening 41 corresponds to the "third opening".

2, a portion of the tip side of the second inner shaft 33 is curved and fixed, so that the tip side of the second lumen 30L is curved in the +Y-axis direction toward the tip second opening 31. Hereinafter, the curved portion of the second lumen 30L is also referred to as the "first curved portion 35". The first curved portion 35 corresponds to the "curved portion". In the longitudinal section of the shaft 10 including the first curved portion 35 (i.e., the cross section shown in FIG. 2), the acute angle θ1 formed by the central axis O1 of the second lumen 30L on the base end side of the first curved portion 35 and the central axis O3 of the first curved portion 35 is 30 degrees or more and 70 degrees or less. In addition, a portion of the tip side of the third inner shaft 43 is curved and fixed, so that the tip side of the third lumen 40L is curved in the -Y-axis direction toward the tip third opening 41. Hereinafter, the curved portion of the third lumen 40L is also referred to as the "second curved portion 45". In FIG. 2, the central axis O4 of the second curved portion 45 is illustrated in a longitudinal section (the section shown in FIG. 2) of the shaft 10 including the second curved portion 45.

As shown in FIG. 3, the relationship between the inner diameter Φ20 of the first lumen 20L, the inner diameter Φ30 of the second lumen 30L, and the inner diameter Φ40 of the third lumen 40L is inner diameter Φ20 < inner diameter Φ30 = inner diameter Φ40. This relationship can be determined arbitrarily depending on the outer diameter of the puncture needle that can be used in the catheter 1, and may be, for example, inner diameter Φ20 < inner diameter Φ40 < inner diameter Φ30.

4, in the longitudinal direction (X-axis direction) of the shaft 10, the distal third opening 41 connected to the third lumen 40L is disposed near the distal second opening 31 connected to the second lumen 30L. In the illustrated example, the distal third opening 41 is disposed on the base end side (+X-axis direction) of the distal second opening 31. Here, it is preferable that the length L1 between the center point O3 of the distal second opening 31 (in other words, the point where the central axis O3 of the first curved portion 35 shown in FIG. 2 intersects with the outer surface of the shaft 10) and the center point O4 of the distal third opening 41 (in other words, the point where the central axis O4 of the second curved portion 45 shown in FIG. 2 intersects with the outer surface of the shaft 10) is about 2 to 5 times the inner diameter of the blood vessel into which the catheter 1 is inserted. For example, if the inside diameter of the blood vessel into which the catheter 1 is inserted is 2 to 4 mm, it is preferable that the length L1 between the center point O3 of the distal end second opening 31 and the center point O4 of the distal end third opening 41 be 10 mm.

The upper part of FIG. 4 shows a schematic diagram showing the relationship between the shaft 10, the tip second opening 31, and the tip third opening 41 as viewed from the longitudinal direction (X-axis direction) of the shaft 10. As shown in the figure, a first line segment LS1 (upper part of FIG. 4: dashed line) is defined connecting the center O of the shaft 10 and the center point O3 of the tip second opening 31. Similarly, a second line segment LS2 is defined connecting the center O of the shaft 10 and the center point O4 of the tip third opening 41 (upper part of FIG. 4: two-dot chain line). At this time, the positional relationship between the tip second opening 31 and the tip third opening 41 is such that the angle formed by the first line segment LS1 and the second line segment LS2 is approximately 180 degrees. In other words, in the circumferential direction of the shaft 10, the tip second opening 31 and the tip third opening 41 are positioned approximately 180 degrees apart.

As shown in the lower part of FIG. 4, the opening area of the tip second opening 31 is larger than the area of the second lumen 30L in the cross section of the shaft 10 (FIG. 3). Similarly, the opening area of the tip third opening 41 is larger than the area of the third lumen 40L in the cross section of the shaft 10 (FIG. 3). Specifically, the tip second opening 31 has an elliptical shape formed by cutting the second inner shaft 33 obliquely. Similarly, the tip third opening 41 has an elliptical shape formed by cutting the third inner shaft 43 obliquely.

The distal tip 71 is joined to the distal end of the shaft 10 and advances through the blood vessel before other components. The distal tip 71 is made of a radiopaque material and functions as a marker indicating the distal end of the catheter 1. As shown in FIG. 2, the distal tip 71 has an outer shape that tapers from the base end to the distal end. A through hole is formed in the approximate center of the distal tip 71, penetrating the distal tip 71 in the longitudinal direction (X-axis direction) of the shaft 10. The first inner shaft 23 is inserted and fixed inside the through hole of the distal tip 71. The outer diameter and length of the distal tip 71 can be determined as desired.

The first marker portion 72 is formed of a radiopaque material and functions as a marker indicating the position of the distal end second opening 31 from which the puncture needle protrudes in the longitudinal direction (X-axis direction) of the shaft 10. As shown in Figures 1, 2, and 4, the first marker portion 72 is an annular member. The first marker portion 72 is disposed near the distal end second opening 31 (in the illustrated example, at a position adjacent to the first marker portion 72) on the distal side of the distal end second opening 31. The first marker portion 72 is bonded to the outer surface of the outer shaft 11. Any bonding agent such as an epoxy adhesive can be used for bonding.

The second marker portion 73 is formed of a material having radiopaque properties and functions as a mark indicating the position of the tip second opening 31 from which the puncture needle protrudes in the circumferential direction (YZ axis direction) of the shaft 10. As shown in FIG. 4, the second marker portion 73 is a disk-shaped member with a hole in the center. The second marker portion 73 is arranged to surround the tip second opening 31 with the center hole aligned with the tip second opening 31. The second marker portion 73 is bonded to the outer surface of the outer shaft 11. Any bonding agent such as an epoxy adhesive can be used for bonding. With this configuration, as shown in FIG. 1, the second marker portion 73 allows the surgeon to recognize the position of the tip second opening 31 in the circumferential direction by the shape of the second marker portion 73 when viewed from any direction.

Returning to FIG. 1, the explanation will be continued. The connector 90 is disposed at the base end of the shaft 10 and is a member that is held by the surgeon. The connector 90 has a branched portion 91 that branches into three and a wing portion 92 that protrudes along the Y axis. The base end of the shaft 10 is inserted and joined to the tip of the branched portion 91. The branched portion 91 has a first branch that extends in the +X-axis direction in FIG. 1, a second branch that extends in the +Y direction, and a third branch that extends in the -Y direction. The first inner shaft 23 is inserted into the inside of the first branch, forming the first lumen 20L. The second inner shaft 33 is inserted into the inside of the second branch, forming the second lumen 30L. The third inner shaft 43 is inserted into the inside of the third branch, forming the third lumen 40L.

The outer shaft 11, the sealing member 12, the first inner shaft 23, and the third inner shaft 43 are preferably antithrombotic, flexible, and biocompatible, and can be made of a resin material or a metal material. Examples of resin materials include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. Examples of metal materials include stainless steel such as SUS304, nickel-titanium alloy, cobalt-chromium alloy, and tungsten steel. Other well-known materials may also be used, and a joint structure combining multiple materials may also be used. The second inner shaft 33 is preferably made of a material having a higher hardness (e.g., Vickers hardness) than the first inner shaft 23 and the third inner shaft 43, and is made of, for example, stainless steel such as SUS304, nickel-titanium alloy, cobalt-chromium alloy, and tungsten steel. As a result, in the catheter 1, the hardness of the inner wall forming the second lumen 30L is higher than the hardness of the inner wall forming the first lumen 20L, and is also higher than the hardness of the inner wall forming the third lumen 40L. The longitudinal length, outer diameter, and inner diameter of each of the outer shaft 11, first inner shaft 23, second inner shaft 33, and third inner shaft 43 may be determined as desired.

The tip tip 71, the first marker portion 72, and the second marker portion 73 can be formed from a resin material or a metal material having radiopaque properties. For example, when a resin material is used, it can be formed by mixing a radiopaque material such as bismuth trioxide, tungsten, or barium sulfate with polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, or fluororesin. For example, when a metal material is used, it can be formed from a radiopaque material such as gold, platinum, or tungsten, or an alloy containing these elements (e.g., platinum-nickel alloy). Other well-known materials may also be used, or a joint structure combining multiple materials may be used. The connector 90 can be formed from a well-known resin material such as polyamide, polypropylene, polycarbonate, polyacetal, or polyethersulfone. The longitudinal length, outer diameter, and inner diameter of each of the tip tip 71, the first marker portion 72, and the second marker portion 73 may be determined arbitrarily.

Figure 5 is a diagram showing an example of drug injection therapy using catheter 1. The upper left of Figure 5 illustrates a patient's heart 100, and the lower right shows the catheter 1 inserted into a target blood vessel 101 of the heart 100. The target blood vessel 101 is a blood vessel in the coronary artery of the heart 100 that is located near a tissue (hereinafter also referred to as the "target tissue") into which the drug is intended to be injected during drug injection therapy.

The procedure for the drug injection treatment using the catheter 1 is illustrated in a1 to a6.
(a1) The surgeon delivers the delivery guide wire 2 to the target blood vessel 101 of the heart 100.
(a2) The surgeon inserts the base end side of the guidewire 2 from the first opening 21 at the tip of the catheter 1 into the first lumen 20L, and then delivers the catheter 1 along the guidewire 2 to a position near the target tissue in the target blood vessel 101.
(a3) The operator inserts the puncture needle 3 into the second lumen 30L from the proximal second opening 32 of the catheter 1. At this point, the tip of the puncture needle 3 is still stored in the second lumen 30L.
(a4) The surgeon inserts the guide wire 4 used as a backup device into the third lumen 40L from the proximal third opening 42 of the catheter 1. Note that a guide wire having higher rigidity than the guide wire 2 is used as the guide wire 4 for the backup device.
(a5) The surgeon pushes the guide wire 4 toward the distal end, causing it to protrude from the distal third opening 41 to the outside, and positions the guide wire 4 inside the target blood vessel 101 in contact with the inner wall of the target blood vessel 101. As a result, as shown in Fig. 5, the distal end of the catheter 1 is raised in the direction opposite to the distal third opening 41 (in other words, in the direction of the distal second opening 31, the direction indicated by the white arrow in Fig. 5).
(a6) The surgeon pushes the puncture needle 3 toward the tip side, protruding it from the tip second opening 31 to the outside, puncturing the target blood vessel 101 and the myocardial wall 102, and injects the medicinal liquid from the puncture needle 3 into the myocardial wall 102. The state of this puncture is illustrated in the lower right of Fig. 5.

Fig. 6 is a diagram showing another example of drug solution injection therapy using the catheter 1. The upper left of Fig. 6 illustrates the patient's heart 100, and the lower right shows the catheter 1 inserted into the target blood vessel 101 of the heart 100. The surgeon may adopt the following steps b4 to b7 instead of steps a4 to a6 described in Fig. 5. According to this example, the highly rigid guidewire 6 is placed in the target blood vessel 101 while covered with the flexible microcatheter 5, which can improve safety compared to the method described in Fig. 5.
(b4) The surgeon inserts a guidewire (not shown) that is more flexible than the guidewire 4 described in Figure 5 into the third lumen 40L from the base end third opening 42 of the catheter 1, and pushes the guidewire toward the tip side, causing it to protrude to the outside from the tip end third opening 41.
(b5) After inserting the base end side of the guidewire into the lumen of the microcatheter 5, the surgeon pushes the microcatheter 5 along the guidewire toward the tip side, causing it to protrude to the outside from the tip third opening 41 and to be positioned inside the target blood vessel 101. The microcatheter 5 is made of a flexible material.
(b6) The operator removes the guidewire from the microcatheter 5, inserts a guidewire 6 having higher rigidity than the guidewire used in steps b4 and b5 into the microcatheter 5, and pushes the guidewire 6 toward the distal end along the microcatheter 5 until it is positioned outside the distal second opening 31 without protruding from the microcatheter 5. Then, the microcatheter 5 including the guidewire 6 having higher rigidity is placed inside the target blood vessel 101 in contact with the inner wall of the target blood vessel 101. As a result, as shown in Fig. 6, the distal end side of the catheter 1 is raised in the opposite direction to the distal third opening 41 (in other words, in the direction of the distal second opening 31, the direction indicated by the white arrow in Fig. 6).
(b7) The operator pushes the puncture needle 3 toward the tip side, protruding it from the tip second opening 31 to the outside, puncturing the target blood vessel 101 and the myocardial wall 102, and injects the medicinal liquid from the puncture needle 3 into the myocardial wall 102. The state of this puncture is illustrated in the lower right of Fig. 6.

As described above, according to the catheter 1 of the first embodiment, the shaft 10 has a first lumen 20L extending to the first tip opening 21 (first opening) of the tip portion, a second lumen 30L extending to the second tip opening 31 (second opening) on the side, and a third lumen 40L extending to the third tip opening 41 (third opening) on the side. Therefore, as described in Figures 5 and 6, the first lumen 20L can be used as a guidewire lumen for inserting the delivery guidewire 2, the second lumen 30L can be used as a needle lumen for the puncture needle 3, and the third lumen 40L can be used as a backup lumen for inserting the backup devices 4, 5, and 6 (e.g., guidewires, catheters, etc.) for applying a puncture force to the puncture needle 3. That is, according to the catheter 1, the tip of the puncture needle 3 can be protruded from the tip second opening 31 (second opening) on the side of the shaft 10 to puncture the myocardial wall 102 (target tissue), so that a medicinal liquid can be injected into the myocardial wall 102 from within the target blood vessel 101. Therefore, similar to the conventional percutaneous coronary intervention (PCI) procedure, the procedure can be completed within the coronary artery without the catheter 1 reaching the ventricle, and the puncture site (medicinal liquid injection site) can be freely selected by moving the catheter 1 within the target blood vessel 101. Furthermore, according to the catheter 1, a puncture force can be applied to the puncture needle 3 using backup devices such as the guide wires 4 and 6 and the catheter 5, so that a puncture force can be applied to the puncture needle 3 without ischemia, compared to the conventional configuration (a configuration in which a puncture force is applied to the puncture needle by expanding an expansion part within a blood vessel). Furthermore, according to the catheter 1, the first lumen 20L functioning as a guidewire lumen is disposed at the center of the shaft 10 in the cross section of the shaft 10, so that the operability of the catheter 1 can be improved when delivering the catheter 1 to the myocardial wall 102 (biological tissue into which the drug solution is intended to be injected). When the tip of the puncture needle 3 is protruded from the tip second opening 31 (second opening) to puncture the myocardial wall 102 with the puncture needle 3 inserted through the first lumen 20L, the guidewire 2 inserted through the first lumen 20L and the backup devices 4, 5, and 6 inserted through the third lumen 40L are subjected to a reaction force against the puncture. In this regard, according to the catheter 1, in the cross section of the shaft 10, the second lumen 30L through which the puncture needle 3 is inserted and the third lumen 40L through which the backup devices 4, 5, and 6 are inserted are disposed on opposite sides of the first lumen 20L. This prevents the reaction force against the puncture from being dispersed in different directions, and prevents the catheter 1 from rotating during the puncture. As a result, the accuracy of the puncture by the puncture needle 3 can be improved.

According to the catheter 1 of the first embodiment, as shown in FIG. 4, the tip second opening 31 (second opening) and the tip third opening 41 (third opening) are arranged at positions approximately 180 degrees apart in the circumferential direction (YZ axis direction) of the shaft 10. Therefore, as shown in FIG. 5 and FIG. 6, the puncture needle 3 protruding from the tip second opening 31 can be supported by the backup devices 4, 5, and 6 protruding from the tip third opening 41 located at a position approximately 180 degrees apart. In other words, it is possible to arrange the backup devices 4, 5, and 6 for supporting the puncture needle 3 by receiving the reaction force in the direction in which the reaction force due to the puncture is generated. As a result, the catheter 1 can be prevented from moving back and forth (longitudinal direction) and from rotating in the circumferential direction due to the reaction force due to the puncture. If the length L1 (FIG. 2) between the distal end second opening 31 and the distal end third opening 41 is set to about 2 to 5 times (e.g., 10 mm) the inner diameter of the blood vessel into which the catheter 1 is inserted, the position where the backup devices 4, 5, and 6 protruding from the distal end third opening 41 contact the inner wall of the target blood vessel 101 and the position of the distal end second opening 31 for protruding the puncture needle 3 can be brought closer together in the longitudinal direction of the catheter 1 (FIGS. 5 and 6). This allows the backup devices 4, 5, and 6 to increase the force with which the puncture needle 3 is supported, and also prevents the catheter 1 from shifting in the longitudinal direction when the puncture needle 3 is inserted.

Furthermore, according to the catheter 1 of the first embodiment, the durability of the catheter 1 can be improved. The puncture needle 3 is configured with a sharp tip for the purpose of puncturing the target tissue. In this regard, according to the catheter 1 of the first embodiment, the hardness of the inner wall forming the second lumen 30L is higher than the hardness of the inner wall forming the first lumen 20L and the inner wall forming the third lumen 40L. Therefore, even if the sharp tip of the puncture needle 3 hits the inner wall of the second lumen 30L when the puncture needle 3 is delivered toward the tip side in the second lumen 30L and the tip of the puncture needle 3 is protruded from the tip second opening 31 (second opening), damage to the inner wall can be suppressed. As a result, the durability of the catheter 1 can be improved.

Furthermore, according to the catheter 1 of the first embodiment, as shown in FIG. 2, the acute angle θ1 formed by the central axis O1 of the second lumen 30L on the base end side of the first curved portion 35 (curved portion) and the central axis O3 of the first curved portion 35 is 30 degrees or more and 70 degrees or less. Therefore, as shown in FIG. 5 and FIG. 6, the puncture angle of the puncture needle 3 protruding from the second lumen 30L can be set to 30 degrees or more and 70 degrees or less, which is suitable for puncture. If the puncture angle is less than 30 degrees, the puncture needle may not easily pierce the target blood vessel 101 or the myocardial wall 102, while if the puncture angle is more than 70 degrees, it becomes difficult to control the penetration depth of the puncture needle. Therefore, by setting the puncture angle to 30 degrees or more and 70 degrees or less, it is possible to realize reliable puncture and to easily control the penetration depth of the puncture needle.

Furthermore, according to the catheter 1 of the first embodiment, as shown in FIG. 4, the opening area of the tip second opening 31 (second opening) is larger than the area of the second lumen 30L in the cross section of the shaft 10, making it easier to protrude the puncture needle 3 from the tip second opening 31.

Furthermore, according to the catheter 1 of the first embodiment, as shown in FIG. 4, the shaft 10 further includes a first annular marker portion 72 having radiopaqueness provided near the distal end second opening 31 (second opening). Therefore, in step a2 described in FIG. 5 and FIG. 6, the surgeon can easily puncture the target tissue with the puncture needle 3 protruding from the distal end second opening 31 by adjusting the front-to-rear position of the catheter 1 so that the first marker portion 72 is located near the target tissue.

Furthermore, according to the catheter 1 of the first embodiment, as shown in FIG. 4, the shaft 10 further includes a radiopaque second marker portion 73 provided near the distal end second opening 31 (second opening), which allows the position of the distal end second opening 31 in the circumferential direction to be recognized based on the shape of the second marker portion 73 when viewed from any direction. Therefore, in step a2 described in FIG. 5 and FIG. 6, the surgeon can easily puncture the target tissue with the puncture needle 3 protruding from the distal end second opening 31 by adjusting the circumferential position of the catheter 1 (rotating the catheter 1) so that the second marker portion 73 is located on the side of the blood vessel wall facing the myocardial wall 102.

Second Embodiment
Fig. 7 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1A of a second embodiment. Fig. 7 shows the configuration of the catheter 1A as viewed from the +Y axis direction, and also shows with dashed lines the tip third opening 41 and the tip fourth opening 51, which are not actually visible from the +Y axis direction. Fig. 8 is an explanatory diagram illustrating the cross-sectional configuration along line CC in Fig. 7. In the second embodiment, a configuration in which the catheter 1A has two backup lumens will be described. The catheter 1A of the second embodiment includes a shaft 10A instead of the shaft 10 in the configuration described in the first embodiment.

As shown in FIG. 8, the shaft 10A further includes a fourth inner shaft 53. The fourth inner shaft 53 is hollow and elongated, and has a substantially circular cross section. The fourth inner shaft 53 is inserted into the lumen of the outer shaft 11 like the other inner shafts, and extends substantially parallel to each other along the longitudinal direction (X-axis direction) of the outer shaft 11. In the cross section shown in FIG. 8, the third inner shaft 43 and the fourth inner shaft 53 are disposed on the opposite side of the second inner shaft 33, sandwiching the first inner shaft 23, in the lumen of the outer shaft 11. The fourth inner shaft 53 has a shorter longitudinal length than the third inner shaft 43, and a portion of the distal end side and a portion of the proximal end side are curved in the -Y-axis direction. As shown in FIG. 7, the distal end of the fourth inner shaft 53 is connected to the outside through a distal fourth opening 51 formed on the side surface of the shaft 10A in the -Y-axis direction. The base end of the fourth inner shaft 53 is connected to the outside through a base end fourth opening formed in a fourth branch (not shown) of the connector 90. The fourth inner shaft 53 can be made of, for example, the same material as the third inner shaft 43. The material of the fourth inner shaft 53 and the material of the third inner shaft 43 may be the same or different.

The fourth lumen 50L formed inside the fourth inner shaft 53 functions as a "second backup lumen" through which a backup device is inserted for the catheter 1A. That is, in the catheter 1A of the second embodiment, the shaft 10A is provided with a fourth lumen 50L arranged in line with the first to third lumens 20L, 30L, and 40L. The inner diameter Φ50 of the fourth lumen 50L may be the same as or different from the inner diameter Φ40 of the third lumen 40L. Also, as shown in FIG. 7, a distal end fourth opening 51 communicating with the fourth lumen 50L is formed on the side of the shaft 10A, closer to the base end than the distal end third opening 41. In the longitudinal direction (X-axis direction) of the shaft 10A, the distal end fourth opening 51 is arranged at a position different from the distal end third opening 41. The length L2 in the longitudinal direction between the center O4 of the distal end third opening 41 and the center O5 of the distal end fourth opening 51 may be determined arbitrarily. In addition, in the circumferential direction (YZ axis direction) of the shaft 10A, the distal fourth opening 51 is disposed at the same position as the distal third opening 41. Here, "the same position" means approximately the same position, and allows for differences due to manufacturing errors, etc. In this embodiment, the distal fourth opening 51 corresponds to the "fourth opening." In the catheter 1A, the hardness of the inner peripheral wall forming the second lumen 30L is higher than the hardness of the inner peripheral wall forming the first lumen 20L, higher than the hardness of the inner peripheral wall forming the third lumen 40L, and higher than the hardness of the inner peripheral wall forming the fourth lumen 50L.

9 is a diagram showing an example of a liquid medicine injection treatment using the catheter 1 A. The procedure of the liquid medicine injection treatment using the catheter 1 A employs the following steps c4 to c7 instead of steps a4 to a6 described in the first embodiment.
(c4) The surgeon inserts a guide wire 4a used as a backup device into the third lumen 40L from the proximal third opening 42 of the catheter 1A.
(c5) The surgeon inserts the guidewire 4b used as a second backup device into the fourth lumen 50L from the fourth opening at the proximal end of the catheter 1A. Note that the guidewires 4a and 4b have higher rigidity than the guidewire 2.
(c6) The operator pushes the guidewires 4a and 4b toward the distal end, causing them to protrude from the distal third opening 41 and the distal fourth opening 51, and positions the guidewires 4a and 4b inside the target blood vessel 101 in contact with the inner wall of the target blood vessel 101. As a result, as shown in Fig. 9, the distal end side of the catheter 1A is raised in the opposite direction to the distal third opening 41 and the distal fourth opening 51 (in other words, in the direction of the distal second opening 31).
(c7) The operator pushes the puncture needle 3 toward the tip side, protruding it from the tip second opening 31 to the outside, puncturing the target blood vessel 101 and the myocardial wall 102, and injects the medicinal liquid from the puncture needle 3 into the myocardial wall 102. The state of this puncture is illustrated in the lower right of Fig. 9.

In this way, the configuration of the catheter 1A can be modified in various ways, and a configuration in which multiple backup devices can be used in combination may be used. The catheter 1A of the second embodiment described above can also achieve the same effects as the first embodiment. In addition, according to the catheter 1A of the second embodiment, the shaft 10A further has a fourth lumen 50L extending to the tip fourth opening 51 (fourth opening) on the side, so that a second backup device 4b other than the backup device 4a inserted into the third lumen 40L can be used in combination. As a result, a stronger puncture force can be applied to the puncture needle 3. In addition, the tip fourth opening 51 is disposed at a different position from the tip third opening 41 (third opening) in the longitudinal direction of the shaft 10A, and is disposed at the same position as the third opening in the circumferential direction of the shaft 10A, so that the backup device 4a and the second backup device 4b can support the catheter 1A and the puncture needle 3 from different positions in the longitudinal direction, as shown in FIG. 9.

Third Embodiment
Fig. 10 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1B of the third embodiment. Fig. 10 shows the configuration of the catheter 1B as seen from the +Y axis direction, and also shows the tip third opening 41B and the tip fourth opening 51B, which are not actually visible from the +Y axis direction, with broken lines. In the third embodiment, the catheter 1B has two backup lumens like the second embodiment, but the positions of the tip third opening 41B and the tip fourth opening 51B are different from those in the second embodiment. The catheter 1B of the third embodiment includes a shaft 10B instead of the shaft 10 in the configuration described in the second embodiment.

The cross-sectional configuration of the shaft 10B taken along line C-C (FIG. 10) is the same as that of the second embodiment described in FIG. 8. On the other hand, as shown in FIG. 10, a distal end fourth opening 51B is formed on the side of the shaft 10B in parallel with the distal end third opening 41B, and communicates with the fourth lumen 50L. In the longitudinal direction (X-axis direction) of the shaft 10B, the distal end fourth opening 51B is disposed at the same position as the distal end third opening 41B. Here, "the same position" means approximately the same position, and allows for differences due to manufacturing errors, etc. Also, in the circumferential direction (YZ-axis direction) of the shaft 10B, the distal end fourth opening 51B is disposed at a different position from the distal end third opening 41B. In this embodiment, the distal end fourth opening 51B corresponds to the "fourth opening". The procedure for drug solution injection therapy using the catheter 1B is the same as that of the second embodiment.

In this way, the configuration of the catheter 1B can be modified in various ways, and a configuration in which multiple backup devices can be used in combination may be used. The catheter 1B of the third embodiment described above can also achieve the same effects as the first embodiment. In addition, according to the catheter 1B of the third embodiment, the shaft 10B further has a fourth lumen 50L extending to the tip fourth opening 51B (fourth opening) on the side, so that a second backup device 4b can be used in addition to the backup device 4a inserted into the third lumen 40L. As a result, a stronger puncture force can be applied to the puncture needle 3. In addition, the tip fourth opening 51B is arranged at the same position as the tip third opening 41B (third opening) in the longitudinal direction of the shaft 10B, and is arranged at a different position from the tip third opening 41B in the circumferential direction of the shaft 10B, so that the backup device 4a and the second backup device 4b can support the catheter 1B and the puncture needle 3 from different positions in the circumferential direction.

Fourth Embodiment
Fig. 11 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1C of a fourth embodiment. Fig. 11 shows the configuration of the catheter 1C as viewed from the +Y axis direction, and also shows with dashed lines the third tip opening 41C, the fourth tip opening 51C, and the fifth tip opening 61, which are not normally visible from the +Y axis direction. Fig. 12 is an explanatory diagram illustrating the cross-sectional configuration along line D-D in Fig. 11. In the fourth embodiment, a configuration in which the catheter 1C has three backup lumens will be described. The catheter 1C of the third embodiment includes a shaft 10C instead of the shaft 10 in the configuration described in the first embodiment.

As shown in FIG. 12, the shaft 10C further includes a fourth inner shaft 53C and a fifth inner shaft 63. The fourth inner shaft 53C and the fifth inner shaft 63 are each hollow and elongated, and have a substantially circular cross section. The fourth inner shaft 53C and the fifth inner shaft 63 are inserted into the lumen of the outer shaft 11 like the other inner shafts, and extend substantially parallel to each other along the longitudinal direction (X-axis direction) of the outer shaft 11. In the cross section shown in FIG. 12, the third inner shaft 43C, the fourth inner shaft 53C, and the fifth inner shaft 63 are disposed on the opposite side of the second inner shaft 33, sandwiching the first inner shaft 23, in the lumen of the outer shaft 11. The fourth inner shaft 53C has a shorter longitudinal length than the third inner shaft 43C and the fifth inner shaft 63. The fourth inner shaft 53C and the fifth inner shaft 63 each have a distal end portion and a proximal end portion curved in the -Y-axis direction. The tip of the fourth inner shaft 53C is connected to the outside through a tip fourth opening 51C formed on the side of the shaft 10C. The base end of the fourth inner shaft 53C is connected to the outside through a base fourth opening formed in the fourth branch (not shown) of the connector 90. The tip of the fifth inner shaft 63 is connected to the outside through a tip fifth opening 61 formed on the side of the shaft 10C. The base end of the fifth inner shaft 63 is connected to the outside through a base fifth opening formed in the fifth branch (not shown) of the connector 90.

The fourth lumen 50L formed inside the fourth inner shaft 53C functions as a "second backup lumen" through which a backup device is inserted for the catheter 1C. The fifth lumen 60L formed inside the fifth inner shaft 63 functions as a "third backup lumen" through which a backup device is inserted for the catheter 1C. That is, in the catheter 1C of the fourth embodiment, the shaft 10C has a fourth lumen 50L and a fifth lumen 60L arranged in line with the first to third lumens 20L, 30L, and 40L. As shown in FIG. 11, a fourth distal opening 51C communicating with the fourth lumen 50L and a fifth distal opening 61 communicating with the fifth lumen 60L are formed on the side of the shaft 10C. In the longitudinal direction (X-axis direction) of the shaft 10C, the third distal opening 41C and the fifth distal opening 61 are arranged at the same position, while the fourth distal opening 51C is arranged at a different position. Here, "the same position" means approximately the same position, and allows for differences due to manufacturing errors, etc. Also, in the circumferential direction (YZ axis direction) of the shaft 10C, the third tip opening 41C, the fourth tip opening 51C, and the fifth tip opening 61 are all located at different positions. In the illustrated example, the fourth tip opening 51C is located closer to the base end (+X axis direction) than the third tip opening 41C and the fifth tip opening 61.

In this way, the configuration of the catheter 1C can be modified in various ways, and it may be configured to be capable of using multiple backup devices in combination. In the example of FIG. 11, a configuration in which three backup devices can be used in combination is illustrated, but a sixth lumen and a seventh lumen may be provided to enable a configuration in which four or more backup devices can be used in combination. The catheter 1C of the fourth embodiment as described above can also achieve the same effects as the first, second, and third embodiments.

Fifth Embodiment
13 is an enlarged cross-sectional view of a portion of the distal end side of the catheter 1D of the fifth embodiment. In the fifth embodiment, a configuration in which the positional relationship between the distal end second opening 31 and the distal end third opening 41D is different from that of the first embodiment will be described. The catheter 1D of the fifth embodiment includes a shaft 10D instead of the shaft 10 in the configuration described in the first embodiment. The distal end third opening 41D formed on the side surface of the shaft 10D is provided at the same position as the distal end second opening 31 in the longitudinal direction (X-axis direction) of the shaft 10D. That is, in this embodiment, the length L1 between the center point O3 of the distal end second opening 31 and the center point O4 of the distal end third opening 41D is 0 mm. Here, "the same position" means approximately the same position, and allows for differences due to manufacturing errors and the like.

In this way, the configuration of the catheter 1D can be modified in various ways, and the positional relationship between the tip second opening 31 and the tip third opening 41D can be changed as desired. For example, the tip third opening 41D may be provided on the tip side of the tip second opening 31 in the longitudinal direction of the shaft 10D. The catheter 1D of the fifth embodiment as described above can achieve the same effects as the first embodiment. Furthermore, the catheter 1D of the fifth embodiment can improve the freedom of device design.

Sixth Embodiment
Fig. 14 is an enlarged cross-sectional view of a portion of the distal end side of a catheter 1E of a sixth embodiment. A cross section of the second inner shaft 33E taken along line E-E is shown in the balloon in the upper part of Fig. 14. In the sixth embodiment, a configuration in which the material of the second inner shaft 33E is different from that in the first embodiment will be described. The catheter 1E of the sixth embodiment includes a second inner shaft 33E instead of the second inner shaft 33 in the configuration described in the first embodiment.

The second inner shaft 33E is formed of a material (e.g., the same material as the first inner shaft 23 and the third inner shaft 43) that is softer than the second inner shaft 33 of the first embodiment. The second inner shaft 33E also has a high hardness portion 36 in a portion. The high hardness portion 36 is a portion formed of a material that is harder (e.g., Vickers hardness) than the other portions, and protects the second inner shaft 33E from the puncture needle 3. The high hardness portion 36 is provided in a portion of the second inner shaft 33E that corresponds to the outside in the bending direction of the first curved portion 35 (curved portion). As shown in the balloon in the upper part of FIG. 14, the range θ in which the high hardness portion 36 is provided in the circumferential direction of the second inner shaft 33E is preferably 240 degrees or more. Note that a high hardness portion may also be provided in the portion corresponding to the outside in the bending direction for the curved portion on the base end side of the second inner shaft 33E (the curved portion extending to the second branch of the connector 90, FIG. 1).

In this way, the configuration of the catheter 1E can be modified in various ways, and the second inner shaft 33E may be formed of a plurality of materials with different hardness depending on the portion. This is also true for the third inner shaft 43. The catheter 1E of the sixth embodiment described above can also achieve the same effect as the first embodiment. The puncture needle 3 has a sharp tip for the purpose of puncturing the target tissue (FIG. 5). According to the catheter 1E of the sixth embodiment, the hardness of the high hardness portion 36 corresponding to the outside in the bending direction of the second inner shaft 33E (inner peripheral wall) that forms the first curved portion 35 (curved portion) of the second lumen 30L is higher than that of the other portions. Therefore, when the puncture needle 3 is delivered toward the tip side in the second lumen 30L and the tip of the puncture needle 3 is projected from the tip second opening 31 (second opening) through the first curved portion 35, even if the sharp tip of the puncture needle 3 hits the inner wall on the outside of the first curved portion 35, damage to the inner wall can be suppressed. As a result, the durability of the catheter 1E can be improved.

Seventh Embodiment
Fig. 15 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1F of the seventh embodiment. Fig. 15 shows the configuration of the catheter 1F as viewed from the +Y axis direction, and indicates with a dashed line the tip third opening 41F, which is not actually visible from the +Y axis direction. In the seventh embodiment, a configuration will be described in which the opening areas of the tip second opening 31F and the tip third opening 41F are smaller than those of the first embodiment. The catheter 1F of the seventh embodiment includes a shaft 10F instead of the shaft 10 in the configuration described in the first embodiment.

The side of the shaft 10F is formed with a tip second opening 31F and a tip third opening 41F. The tip second opening 31F (second opening) is equal to the area of the second lumen 30L in the cross section of the shaft 10F. Here, "equal" means roughly the same, allowing for differences due to manufacturing errors and the like. Similarly, the tip third opening 41F (third opening) is equal to the area of the third lumen 40L in the cross section of the shaft 10F. In this way, the configuration of the catheter 1F can be modified in various ways, and the opening area of the tip first opening 21F and the opening area of the tip second opening 31F can be determined arbitrarily. The catheter 1F of the seventh embodiment as described above can also achieve the same effects as the first embodiment.

Eighth Embodiment
Fig. 16 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1G of an eighth embodiment. Fig. 16 shows the configuration of the catheter 1G as viewed from the +Y axis direction, and indicates with a dashed line the tip third opening 41, which is not normally visible from the +Y axis direction. In the eighth embodiment, a configuration in which the shape of the second marker portion 73G is different will be described. The catheter 1G of the eighth embodiment includes a shaft 10G instead of the shaft 10 in the configuration described in the first embodiment.

The shaft 10G has a second marker portion 73G instead of the second marker portion 73. The second marker portion 73G is radiopaque and functions as a mark indicating the position of the tip second opening 31 from which the puncture needle 3 protrudes in the circumferential direction (YZ axis direction) of the shaft 10. As shown in FIG. 16, the second marker portion 73G is formed by winding a radiopaque wire in a spiral shape along the outer circumferential surface of the shaft 10G. With such a configuration, the second marker portion 73G can enable the surgeon to recognize the position of the tip second opening 31 in the circumferential direction by the shape of the second marker portion 73G when viewed from any direction. In this way, the configuration of the catheter 1G can be changed in various ways, and the shape of the second marker portion 73G is not limited to a disk shape, and various shapes can be adopted. The catheter 1G of the eighth embodiment as described above can also achieve the same effect as the first embodiment.

Ninth embodiment
Fig. 17 is an explanatory diagram illustrating the configuration of the tip side of a catheter 1H of a ninth embodiment. Fig. 17 shows the configuration of the catheter 1H as viewed from the +Y axis direction, and indicates with a dashed line the tip third opening 41, which is not normally visible from the +Y axis direction. In the ninth embodiment, a configuration that does not have a radiopaque marker portion will be described. The catheter 1H of the ninth embodiment includes a shaft 10H instead of the shaft 10 and a tip tip 71H instead of the tip tip 71 in the configuration described in the first embodiment.

The shaft 10H does not have the first marker portion 72 and the second marker portion 73 described in the first embodiment. The tip tip 71H has a shape similar to that of the tip tip 71 described in the first embodiment, but is made of a material that is not radiopaque. In this way, the configuration of the catheter 1H can be modified in various ways, and it does not have to have a radiopaque marker portion. In the example of FIG. 17, a configuration that does not have any of the tip tip 71 (the tip tip 71 described in the first embodiment), the first marker portion 72, and the second marker portion 73 that are radiopaque is described, but the catheter 1H may be configured to not have one or more of these. The catheter 1H of the ninth embodiment described above can also achieve the same effects as the first embodiment.

Tenth Embodiment
Fig. 18 is an explanatory diagram illustrating a cross-sectional configuration of a catheter 1I of a tenth embodiment. Fig. 18 shows the cross-sectional configuration along line A-A in Fig. 2. In the tenth embodiment, an example in which a shaft 10I is integrally configured will be described. The catheter 1I of the tenth embodiment includes a shaft 10I instead of the shaft 10 in the configuration described in the first embodiment.

The shaft 10I does not have the outer shaft 11, the first inner shaft 23, the second inner shaft 33, the third inner shaft 43, and the sealing member 12 described in the first embodiment, and is composed of a single main body 19. The main body 19 can be formed of any resin material or metal material, similar to the outer shaft 11 described in the first embodiment. The main body 19 has a first lumen 20L, a second lumen 30L, and a third lumen 40L, similar to the first embodiment. In this way, the configuration of the catheter 1I can be changed in various ways, and the shaft 10I may be composed of a single main body 19. The catheter 1I of the tenth embodiment described above can also achieve the same effects as the first embodiment.

Eleventh Embodiment
Fig. 19 is an explanatory diagram illustrating the configuration of the base end side of a catheter 1J of an eleventh embodiment. In Fig. 19, the first lumen 20L, the second lumen 30L, and the third lumen 40L are indicated by dashed lines, as in Fig. 1. In the eleventh embodiment, an example in which the configuration of the base end side is different from that of the first embodiment will be described. The catheter 1J of the eleventh embodiment includes first to third inner shafts 23J, 33J, and 43J instead of the first to third inner shafts 23, 33, and 43 in the configuration described in the first embodiment, and includes a connector 80 instead of the connector 90.

The connector 80 has an operating portion 81, a first end member 82, a second end member 83, and a third end member 84. The operating portion 81 is a member having a substantially cylindrical shape, and a plurality of protrusions 85 are provided on the outer circumferential surface. In the illustrated example, the protrusions 85 are linear and extend in the X-axis direction, but the protrusions 85 can have any shape. The first end member 82, the second end member 83, and the third end member 84 are each a substantially cylindrical member having a pair of protruding wing portions.

The first inner shaft 23J, the second inner shaft 33J, and the third inner shaft 43J have the same configuration as in the first embodiment, except for the following points. Specifically, the first inner shaft 23J, the second inner shaft 33J, and the third inner shaft 43J each extend further toward the base end side (+X axis side) than the base end 11p of the outer shaft 11. The base end of the first inner shaft 23J is fixed to the first end member 82 while being inserted inside the first end member 82. The opening on the base end side of the first end member 82 corresponds to the base end first opening 22J for inserting a guide wire. The base end of the second inner shaft 33J is fixed to the second end member 83 while being inserted inside the second end member 83. The opening on the base end side of the second end member 83 corresponds to the base end second opening 32J for inserting a puncture needle. The base end of the third inner shaft 43J is inserted inside the third end member 84 and fixed to the third end member 84. The opening on the base end side of the third end member 84 corresponds to the base end third opening 42J for inserting the backup device.

As described in FIG. 3, the first inner shaft 23J, the second inner shaft 33J, and the third inner shaft 43J are each fixed to the outer shaft 11 by a sealing member 12. Also, as shown in FIG. 19, the base end of the outer shaft 11 is fixed to the operating part 81 while being inserted inside the operating part 81. The joint 86 that fixes the operating part 81 and the outer shaft 11 can be made of any bonding agent, for example, metal solder such as silver solder, gold solder, zinc, Sn-Ag alloy, Au-Sn alloy, or adhesive such as epoxy adhesive.

5 and 6, when adjusting the circumferential position of the catheter 1J (rotating the catheter 1J) so that the distal end second opening 31 (FIG. 2) is located on the side of the vascular wall facing the myocardial wall 102, the surgeon need only rotate the operation unit 81 in the catheter 1J of this embodiment. For example, assume that the surgeon rotates the operation unit 81 in the D1 direction (FIG. 19: bold black arrow). In this case, the outer shaft 11 fixed to the operation unit 81 also rotates in the D1 direction in conjunction with the rotation of the operation unit 81. Similarly, the first inner shaft 23J, the second inner shaft 33J, and the third inner shaft 43J fixed to the outer shaft 11 also rotate in the D1 direction.

In this way, the configuration of the catheter 1J can be modified in various ways, and the catheter 1J may be configured to include a connector 80 having an operating unit 81 instead of the connector 90. The catheter 1J of the eleventh embodiment described above can achieve the same effects as the first embodiment. In addition, according to the catheter 1J of the eleventh embodiment, by performing a rotation operation on the operating unit 81 fixed to the base end of the outer shaft 11, the outer shaft 11 can be rotated by the rotation applied to the operating unit 81, and the first, second, and third inner shafts 23J, 33J, and 43J fixed to the outer shaft 11 can be rotated. Therefore, the catheter 1J can be easily rotated to adjust the circumferential position of the catheter 1J in the blood vessel, improving usability.

<Twelfth embodiment>
FIG. 20 is an explanatory diagram illustrating the configuration of the base end side of the catheter 1K of the 12th embodiment. In FIG. 20, the first lumen 20L, the second lumen 30L, and the third lumen 40L are indicated by dashed lines, as in FIG. 1. FIG. 21 is an explanatory diagram illustrating the cross-sectional configuration along the line F1-F1 in FIG. 20. FIG. 22 is an explanatory diagram illustrating the cross-sectional configuration along the line F2-F2 in FIG. 20. In the 12th embodiment, an example in which the configuration of the connector 80K is different from that of the 11th embodiment will be described. The catheter 1K of the 12th embodiment includes a shaft 10K instead of the shaft 10 and a connector 80K instead of the connector 80 in the configuration described in the 11th embodiment.

In addition to the components described in the eleventh embodiment, the connector 80K further includes a support portion 87 and a connection portion 88. The support portion 87 is a member having a substantially cylindrical shape, and is provided closer to the base end than the operation portion 81. The connection portion 88 is a member having a substantially cylindrical shape, and is joined to the outer circumferential surface of the support portion 87 with the inner cavity connected to the support portion 87. The support portion 87 and the connection portion 88 do not rotate even when the operation portion 81 is rotated.

The shaft 10K has the same configuration as the eleventh embodiment, except for the following points. Specifically, as shown in FIG. 21, the shaft 10K does not have a sealing member 12 arranged inside the outer shaft 11. As shown in FIG. 21, an outer lumen 11L through which a fluid can flow is formed inside the outer shaft 11. Also, as shown in FIG. 22, a fixing member 89 is provided at the base end of the shaft 10K. The fixing member 89 fixes the first inner shaft 23J, the second inner shaft 33J, and the third inner shaft 43J inside the base end of the outer shaft 11. In the cross section shown in FIG. 22, the fixing member 89 is arranged on a part of the inner surface of the outer shaft 11 and on the entire outer surface of the first, second, and third inner shafts 23J, 33J, and 43J. With this configuration, the shaft 10K has an outer lumen 11L through which a fluid can flow, even in the part where the fixing member 89 is provided. Similarly, the vicinity of the first curved portion 35 on the tip side of the second inner shaft 33J and the vicinity of the second curved portion 45 on the tip side of the third inner shaft 43J (FIG. 2) are fixed to the inside of the outer shaft 11 by a fixing member (not shown).

In this way, the configuration of the catheter 1J can be modified in various ways, and may include a connector 80K having a support portion 87 and a connection portion 88. Also, the catheter 1K of the 12th embodiment may include a shaft 10K having an outer lumen 11L. The catheter 1K of the 12th embodiment described above can achieve the same effects as the first and 11th embodiments. Furthermore, according to the catheter 1K of the 12th embodiment, the connector 80K has a support portion 87 and a connection portion 88 that do not rotate with the rotation operation of the operation portion 81, so that the operator can rotate the operation portion 81 while supporting the support portion 87, thereby further improving usability. Also, according to the catheter 1K of the 12th embodiment, the shaft 10K has an outer lumen 11L, so that the operator can connect a syringe to the connection portion 88 and supply physiological saline to the outer lumen 11L through the inner cavities of the support portion 87 and the connection portion 88.

<Modifications of this embodiment>
The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[Modification 1]
In the above first to twelfth embodiments, the configurations of the catheters 1, 1A to 1K are exemplified. However, the configuration of the catheter 1 can be modified in various ways. For example, a port (opening) that connects the first lumen 20L (guidewire lumen) to the outside may be provided on the side surface of the shaft 10, which is closer to the base end than the distal end second opening 31 and the distal end third opening 41. The catheter may be used as an Rx type catheter by drawing out a delivery guidewire from this port. For example, at least one of the outer peripheral surface and the inner peripheral surface of the shaft 10 may be coated with a hydrophilic or hydrophobic resin.

For example, a portion of the shaft 10 on the tip side may have the configuration described in the first embodiment (FIG. 3), and a portion of the base side may have the configuration described in the tenth embodiment (FIG. 18). In this way, the tip side, which requires machining of the tip second opening 31, base third opening 42, first curved portion 35, and second curved portion 45, can be configured using an outer shaft and inner shaft that are easy to machine (FIG. 3), and the base side, which does not require machining of these, can be configured using an integrated main body portion that can be made thinner (FIG. 18).

For example, in a longitudinal section (FIG. 2) of the shaft 10 including the first curved portion 35, the acute angle θ1 formed by the central axis O1 of the second lumen 30L on the proximal side of the first curved portion 35 and the central axis O3 of the first curved portion 35 may be less than 30 degrees or greater than 70 degrees.

[Modification 2]
The configurations of the catheters 1, 1A to 1K of the first to twelfth embodiments and the configurations of the first modified example may be appropriately combined. For example, in the configuration having a plurality of backup lumens described in the second to fourth embodiments, the position of the distal end third opening 41D described in the fifth embodiment may be adopted, the second inner shaft 33E described in the sixth embodiment may be adopted, the opening area described in the seventh embodiment may be adopted, the marker portion described in the eighth and ninth embodiments may be adopted, the structure of the shaft 10I described in the tenth embodiment may be adopted, and the configuration of the base end side described in the eleventh and twelfth embodiments may be adopted. For example, in the catheter 1D described in the fifth embodiment, the second inner shaft 33E described in the sixth embodiment may be adopted, the opening area described in the seventh embodiment may be adopted, the marker portion described in the eighth and ninth embodiments may be adopted, the structure of the shaft 10I described in the tenth embodiment may be adopted, and the configuration of the base end side described in the eleventh and twelfth embodiments may be adopted. For example, in the catheter 1E described in the sixth embodiment, the opening area described in the seventh embodiment may be adopted, the marker portion described in the eighth and ninth embodiments may be adopted, the structure of the shaft 10I described in the tenth embodiment may be adopted, or the base end configuration described in the eleventh and twelfth embodiments may be adopted.

Although this aspect has been described above based on the embodiment and modified examples, the embodiment of the above-mentioned aspect is intended to facilitate understanding of this aspect and does not limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

1, 1A to 1K... Catheter 2... Delivery guide wire 3... Puncture needle 4, 4a, 4b... Guide wire (backup device)
5...Microcatheter (backup device)
6...Guide wire (backup device)
Reference Signs List 10, 10A to 10D, 10F to 10I, 10K... shaft 11L... outer lumen 11... outer shaft 12... sealing member 19... main body 20L... first lumen 21, 21F... distal end first opening 22, 22J... proximal end first opening 23, 23J... first inner shaft 30L... second lumen 31, 31F... distal end second opening 32, 32J... proximal end second opening 33, 33E, 33J... second inner shaft 35... first curved portion 36... high hardness portion 40L... third lumen 41, 41B, 41C, 41D, 41F... distal end third opening 42, 42J... proximal end third opening 43, 43C, 43J... third inner shaft 45... second curved portion 50L... fourth lumen 51, 51B, 51C... fourth distal opening 53, 53C... fourth inner shaft 60L... fifth lumen 61... fifth distal opening 63... fifth inner shaft 71, 71H... distal tip 72... first marker portion 73, 73G... second marker portion 80... connector 81... operation portion 82... first end member 83... second end member 84... third end member 85... protrusion 86... joint portion 87... support portion 88... connection portion 89... fixing member 90... connector 91... branch portion 92... wing portion

Claims (9)

A catheter having a shaft,
The shaft is
a first lumen extending in a longitudinal direction of the shaft;
a second lumen disposed alongside the first lumen;
a third lumen arranged in parallel with the first lumen and the second lumen,
A first opening formed at a tip portion of the shaft and communicating with the first lumen;
a second opening formed on a side surface of the shaft at a position closer to the base end than the first opening and communicating with the second lumen;
a third opening formed on a side surface of the shaft at a position closer to the base end than the first opening and communicating with the third lumen;
Equipped with
In a cross section of the shaft, the first lumen is disposed at a center of the shaft, and the second lumen and the third lumen are disposed on opposite sides of the first lumen,
In the longitudinal direction of the shaft, a position where the second opening is formed is different from a position where the third opening is formed,
A catheter , wherein the hardness of an inner circumferential wall forming the second lumen is higher than the hardness of an inner circumferential wall forming the first lumen and an inner circumferential wall forming the third lumen . 2. The catheter of claim 1,
The third opening is disposed adjacent to the second opening in a longitudinal direction of the shaft,
A catheter, wherein when viewed in the longitudinal direction of the shaft, a first line segment connecting the center of the shaft and the center point of the second opening, and a second line segment connecting the center of the shaft and the center point of the third opening, form an angle of approximately 180 degrees between the first line segment and the second line segment. The catheter according to claim 1 or 2 ,
A distal end side of the second lumen is curved toward the second opening,
A catheter, in which, in a longitudinal cross-section of the shaft including the curved portion , the acute angle formed by the central axis of the second lumen on the base end side of the curved portion and the central axis of the curved portion is greater than or equal to 30 degrees and less than 70 degrees. The catheter according to any one of claims 1 to 3 ,
The shaft further comprises:
a fourth lumen arranged in parallel with each of the first lumen, the second lumen, and the third lumen;
a fourth opening formed on a side surface of the shaft at a position closer to the base end than the first opening and communicating with the fourth lumen;
Equipped with
The fourth opening is disposed at a different position from the third opening in the longitudinal direction of the shaft,
A catheter, wherein the fourth opening is positioned at the same position as the third opening in the circumferential direction of the shaft. The catheter according to any one of claims 1 to 3 ,
The shaft further comprises:
a fourth lumen arranged in parallel with each of the first lumen, the second lumen, and the third lumen;
a fourth opening formed on a side surface of the shaft at a position closer to the base end than the first opening and communicating with the fourth lumen;
Equipped with
The fourth opening is disposed at the same position as the third opening in the longitudinal direction of the shaft,
A catheter, wherein the fourth opening is positioned at a different position in the circumferential direction of the shaft than the third opening. The catheter according to any one of claims 1 to 5 ,
A catheter, wherein the opening area of the second opening is greater than the area of the second lumen in a cross section of the shaft. The catheter according to any one of claims 1 to 6 ,
The shaft further comprises:
A catheter comprising a first annular marker portion having radiopacity and provided on a side surface of the shaft near the second opening. A catheter according to any one of claims 1 to 7 ,
The shaft further comprises:
A catheter comprising a radiopaque second marker portion provided on a side of the shaft near the second opening, the second marker portion enabling the position of the second opening in the circumferential direction to be recognized based on the shape of the second marker portion when viewed from any direction. A catheter according to any one of claims 1 to 8 ,
The shaft further comprises:
An outer shaft;
a first inner shaft having the first lumen therein;
a second inner shaft having the second lumen therein;
a third inner shaft having the third lumen therein;
Equipped with
the first inner shaft, the second inner shaft, and the third inner shaft each extend to a proximal end side beyond a proximal end of the outer shaft when inserted inside the outer shaft, and at least a proximal end portion is fixed to the outer shaft,
The catheter further comprises a rotatable operating portion fixed to the base end of the outer shaft.

Images