JP2005211308A - Catheter and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter in which fluid injected inside a base shaft lumen is excellently distributed without the crush of a tip shaft lumen at the joined part of the base end of a tip shaft and the tip of a base part shaft, and a manufacturing method thereof. <P>SOLUTION: The catheter 1 is provided with the base shaft 2, the tip shaft 3 and an inner tube 4 arranged inside the tip shaft 3. The inner tube 4 and the tip part of the base shaft 2 are arranged roughly in parallel near the base end of the tip shaft 3, and the base end part of the tip shaft 3, the tip part of the base shaft 2 and the inner tube 4 are fused while the tip shaft lumen 31 formed between the inner surface of the tip shaft 3 and the outer surface of the inner tube 4 communicates with the base shaft lumen 21 formed inside the base shaft 2. A tube 5 for securing the lumen, whose base end is positioned inside the base shaft lumen 21 and tip is positioned in the tip shaft lumen 31, is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a catheter for treatment or examination inserted into a living organ such as a blood vessel, bile duct, trachea, esophagus, urethra, and other organs. In particular, it relates to a rapid exchange catheter.

In a balloon catheter for blood vessel insertion represented by a catheter (hereinafter referred to as “PTCA catheter”) used for PTCA (Percutaneous Transluminal Coronary Angioplasty), a lumen for expanding the balloon is used. In addition, a guide wire lumen for inserting a guide wire is formed over the entire length of the catheter. The guide wire is inserted into the guide wire insertion lumen, and the guide wire is inserted into the blood vessel with the distal end portion protruding from the catheter.
When performing the PTCA procedure, a plurality of PTCA catheters having different outer diameters of the catheter shaft, outer diameters of the balloon during expansion, and the like are prepared. Then, after insertion of the first catheter into the blood vessel, the catheter may be replaced with another catheter. Such replacement of the catheter is preferably performed while the guide wire is left in the blood vessel in order to reduce the burden on the patient, reduce the operation time and labor, prevent infection, and the like. In a catheter called a rapid exchange type catheter, an opening for inserting a guide wire is formed not on the proximal end of the catheter but on the side surface on the distal end side of the catheter. For this reason, in this catheter, replacement | exchange of the catheter with the guide wire indwelling in the blood vessel is easy.
As such a rapid exchange type catheter, there is one shown in JP-T-2003-517901 (Patent Document 1). The catheter 10 shown in FIG. 8 of Patent Document 1 includes a sleeve 42 provided around the distal portion of the support mandrel 22. A sleeve 42 is disposed within the inflation lumen and is secured to the intermediate tubular member 34 to secure the distal portion of the support mandrel 22. The distal portion of the support mandrel 22 extends from the sleeve 42 beyond about 1 cm to about 10 cm.
Moreover, as a rapid exchange type catheter, there is one shown in International Publication No. 03/47679 (Patent Document 2). Similar to Patent Document 1, the one disclosed in Patent Document 2 discloses disposing a tubular reinforcing body around or inside the proximal end portion of the inner tube or the distal end portion of the base shaft. Examples of the material of the reinforcing body include polyimide and a material having a high glass transition temperature. And a tubular reinforcement body is the inner periphery (FIG. 1, FIG. 5 of patent document 2), the circumference | surroundings (FIG. 8 of patent document 2) of an inner pipe base end part, or an inner pipe base end. It arrange | positions inside the part (FIG. 11 of patent document 2).
In addition, the present invention association publication technique 98-7554 (Non-Patent Document 1) by the present applicant discloses a rapid exchange type catheter and a method for manufacturing the same.

Special table 2003-517901 gazette International Publication No. 03/47679 Invention Association Open Technique 98-7554 (Release Date: 1998, 11, 2)

In the catheters of Patent Document 1 and Patent Document 2, since the distal ends of the sleeve and the reinforcing body are located at the distal end of the base shaft, the distal shaft, the inner tube, and the distal end portion of the base shaft at the time of fusion of the base shaft, Although the base shaft and the sleeve (reinforcing body) are not present on the tip side from the tip of the base shaft, the shaft forming material that melts at the time of fusion is used unless the inner core is secured. In some cases, the resin flows into the lumen, causing the collapse of the lumen, which hinders the flow resistance of the fluid injected into the base shaft lumen.
In the non-patent document 1, the expansion lumen securing cored bar is inserted into the lumen between the inner tube and the tip shaft and the lumen of the intermediate shaft, and these are heat-sealed. Thereafter, the intermediate shaft and the base shaft were bonded or fused. On the other hand, the core for securing the expansion lumen is formed on the tip side of the core corresponding to the portion where the two lumens are aligned in order to form the opening of the rapid exchange where the guide wire lumen and the expansion lumen are aligned as thin as possible. It is necessary to make the cross section of the part into a horizontally long oval shape, but it is difficult to manufacture a cored bar having such a shape and is difficult to manufacture. Durability (strength) is inferior, and there is a problem that the metal core is easily broken or bent at the flat portion (small diameter portion).
On the other hand, from the viewpoint of manufacturing cost, it is preferable to form a catheter by directly heat-sealing the tip shaft, the inner tube, and the base shaft without using the intermediate shaft. It is essential to insert and remove the metal core from the end. For this reason, the length of the core for securing the lumen is inevitably longer than the entire length of the base shaft, and the process of taking in and out the core of 1 m or more is very complicated.
Therefore, in the present invention, the distal shaft lumen does not collapse at the joint portion between the proximal end of the distal shaft and the distal end of the base shaft as described above, and the flow of the fluid injected into the proximal shaft lumen is prevented. The present invention provides a good catheter and a method for manufacturing the same.

What achieves the above object is as follows.
(1) It has a base shaft, a tip shaft, and an inner tube arranged in the tip shaft, and in the vicinity of the base end of the tip shaft, the inner tube and the tip of the base shaft are almost In a state where the tip shaft lumen formed between the inner surface of the tip shaft and the outer surface of the inner tube and the base shaft lumen formed in the base shaft communicate with each other while being arranged in parallel. A catheter in which a proximal end portion of the distal shaft, a distal end portion of the proximal shaft, and the inner tube are fused, wherein the proximal end is located in the lumen of the proximal shaft, and the distal end is the distal shaft. A catheter comprising a lumen securing tube located in a lumen.
(2) The tip of the base shaft does not penetrate into the tip shaft, and a part of the inner surface of the tip of the base shaft contacts a part of the outer surface of the base end of the tip shaft. The catheter according to (1) above, wherein
(3) The lumen securing tube is formed of a material having a higher melting point or a thermosetting resin material than a material for forming the distal end shaft, the inner tube, and the base shaft. The catheter according to 1.
(4) The catheter according to (3), wherein the material having a high melting point or the thermosetting resin material is any one of thermoplastic polyimide, thermosetting polyimide, and metal.
(5) The catheter according to any one of (1) to (4), wherein the lumen securing tube includes a slit or a recess extending in a spiral or parallel to the axial direction.
(6) The catheter according to any one of (1) to (4), wherein the lumen securing tube is a coil body.

(7) The distal end of the inner tube protrudes a predetermined length from the distal shaft, and the catheter has a distal end fixed to the distal end of the inner tube, and a proximal end fixed to the distal end of the distal shaft. The catheter according to any one of (1) to (6), further comprising a balloon that is expandable by a fluid flowing into the lumen of the distal shaft.
(8) The catheter according to any one of (1) to (7), wherein the inner tube includes a guide wire insertion opening that opens at a proximal end of the distal shaft or in the vicinity thereof.
(9) The catheter includes a rigidity imparting body that extends from a proximal end side of the base shaft lumen, penetrates the lumen securing tube, and extends to a distal end side of the distal shaft lumen. Thru | or the catheter in any one of (8).
(10) The distal end of the lumen securing tube is located on the distal end side of the catheter from the proximal end portion of the distal shaft, the distal end portion of the base shaft, and the distal end of the fusion portion of the inner tube. The catheter according to any one of 1) to (9).
(11) The proximal end of the lumen securing tube is located closer to the proximal end of the catheter than the proximal end of the distal shaft, the distal end of the proximal shaft, and the proximal end of the fused portion of the inner tube. The catheter according to any one of (1) to (10) above.

(12) a proximal shaft, a distal shaft, and an inner tube disposed in the distal shaft, and in the vicinity of the proximal end of the distal shaft, the inner tube and the distal end of the base shaft are approximately In a state where the tip shaft lumen formed between the inner surface of the tip shaft and the outer surface of the inner tube and the base shaft lumen formed in the base shaft communicate with each other while being arranged in parallel. A method of manufacturing a catheter in which the proximal end of the distal shaft, the distal end of the proximal shaft, and the inner tube are fused,
Preparing a base shaft having at least a distal end portion formed of a thermoplastic resin, a tip shaft having at least a proximal end portion formed of a thermoplastic resin, an inner tube, and a lumen securing tube;
Placing the inner tube in the tip shaft;
In the vicinity of the proximal end of the distal shaft, the inner tube and the distal end portion of the base shaft are arranged substantially in parallel, the proximal end is located in the proximal shaft lumen, and the distal end is in the distal shaft lumen. Arranging the lumen securing tube to be positioned;
A catheter manufacturing method comprising: a fusion step of fusing the distal end portion of the base shaft, the proximal end portion of the distal shaft, and the inner tube after all the steps described above.

(13) The catheter includes a rigidity imparting body extending from a proximal end side of the base shaft lumen, penetrating the lumen securing tube, and extending to a distal end side of the distal shaft lumen. The manufacturing method of the method includes the steps of preparing the rigidity imparting body and, prior to the fusing process, penetrating the rigidity securing body extending from the proximal end side of the base shaft lumen through the lumen securing tube, and The method for producing a catheter according to the above (10), wherein the step of arranging to extend toward the distal end side of the lumen is performed.
(14) The fusion process includes encapsulating a predetermined region before and after the proximal end of the distal shaft and the distal end portion of the base shaft with a heat-shrinkable tube, heating the predetermined region together with the heat-shrinkable tube, and heat shrinking The method for producing a catheter according to (12) or (13) above, wherein the tube is contracted and brought into close contact, and the distal end portion of the base shaft, the proximal end portion of the distal shaft, and the inner tube are fused.
(15) As the heat shrinkable tube, a tube shorter than the lumen securing tube is used, and in the fusing step, the distal end of the lumen securing tube is located on the distal side from the distal end of the heat shrinkable tube, The catheter manufacturing method according to the above (14), which is performed in a state where the proximal end of the lumen securing tube is located closer to the proximal end side than the proximal end of the heat shrinkable tube.

The catheter of the present invention has a base shaft, a tip shaft, and an inner tube disposed in the tip shaft, and in the vicinity of the base end of the tip shaft, the tip of the inner tube and the base shaft. Are arranged substantially in parallel, and the tip shaft lumen formed between the inner surface of the tip shaft and the outer surface of the inner tube communicates with the base shaft lumen formed in the base shaft In the catheter, the proximal end of the distal shaft, the distal end of the proximal shaft, and the inner tube are fused, and the proximal end of the catheter is located in the lumen of the proximal shaft, and the distal end is A lumen securing tube located in the distal shaft lumen is provided.
In particular, since the lumen securing tube protrudes from the distal end of the base shaft and penetrates into the distal shaft, the distal shaft lumen collapses at the joint between the proximal end of the distal shaft and the distal end of the base shaft. There is no flow of fluid injected into the base shaft lumen

If the lumen securing tube is formed of a material having a higher melting point or a thermosetting resin material than the material for forming the tip shaft, the inner tube, and the base shaft, the inside of the tip shaft is further increased. Secure the cavity.
Further, if the lumen securing tube has a slit or a recess extending in a parallel or spiral manner in the axial direction or a coil body, the catheter is deformed well at the fused portion, and the catheter is operated. Improves.
Further, the catheter extends from the proximal end side of the base shaft lumen, penetrates the lumen securing tube, and includes a rigidity imparting body extending to the distal end side of the distal shaft lumen. Transmission of the pushing force applied at the proximal end portion of the catheter to the distal end portion is enhanced, and the operability of the catheter is improved.
In addition, the distal end of the lumen securing tube may be located closer to the distal end of the catheter than the proximal end of the distal shaft, the distal end of the base shaft, and the distal end of the fused portion of the inner tube. As a result, it is possible to secure the distal shaft lumen more reliably.
The proximal end of the lumen securing tube is located closer to the proximal end of the catheter than the proximal end of the distal shaft, the distal end of the base shaft, and the proximal end of the fused portion of the inner tube. If it is a thing, the securing of the base shaft lumen will be ensured.

The catheter manufacturing method of the present invention includes a base shaft, a distal shaft, and an inner tube disposed in the distal shaft, and the inner tube and the The distal end of the base shaft is disposed substantially in parallel, the distal shaft lumen formed between the inner surface of the distal shaft and the outer surface of the inner tube, and the base shaft lumen formed in the base shaft In a state where the proximal end of the distal shaft, the distal end of the proximal shaft, and the inner tube are fused, at least the distal end is formed of a thermoplastic resin. Preparing a base shaft, a tip shaft having at least a base end portion formed of a thermoplastic resin, an inner tube and a lumen securing tube, and disposing the inner tube in the tip shaft In the vicinity of the proximal end of the distal shaft, the inner tube and the distal end of the base shaft are arranged substantially in parallel, the proximal end is located in the lumen of the proximal shaft, and the distal end is in the distal shaft. After arranging the lumen securing tube so as to be located in the cavity and all the above steps, the distal end portion of the base shaft, the proximal end portion of the distal shaft and the inner tube are heated and fused together. And a fusing process.
For this reason, the catheter which has the above effects can be manufactured easily, without using a metal core.

The catheter includes a rigidity imparting body that extends from a proximal end side of the base shaft lumen, penetrates the lumen securing tube, and extends to a distal end side of the distal shaft lumen. The manufacturing method includes the steps of preparing the rigidity imparting body and, before the fusion process, passing the rigidity imparting body extending from the proximal end side of the base shaft lumen through the lumen securing tube, In addition to the above-described effects, if the step of placing the cavity so as to extend toward the distal end side of the cavity is performed, the push force applied at the proximal end portion of the catheter is highly transmitted to the distal end portion, and the operability of the catheter is improved. Can be easily manufactured without using a cored bar.
In the fusing step, a predetermined region before and after the proximal end of the distal shaft and the distal end portion of the base shaft is encapsulated with a heat shrinkable tube, and the predetermined region is heated together with the heat shrinkable tube. Can be easily and reliably carried out if the distal end portion of the base shaft, the proximal end portion of the distal shaft, and the inner tube are fused.
Further, as the heat shrinkable tube, a tube shorter than the lumen securing tube is used, and in the fusing step, the distal end of the lumen securing tube is located on the distal side from the distal end of the heat shrinkable tube, If it is performed in a state where the base end of the cavity securing tube is located on the base end side from the base end of the heat shrinkable tube, the tube is secured in a state in which the distal end shaft lumen and the base shaft lumen are secured more securely. You can wear.

A description will be given of an embodiment in which the catheter of the present invention is applied to a PTCA catheter.
FIG. 1 is a front view of an embodiment in which the catheter of the present invention is applied to a PTCA catheter, and FIG. 2 is an enlarged view of the vicinity of the joint between the distal shaft and the base shaft in the catheter shown in FIG. 3 is an enlarged cross-sectional view of the vicinity of the joint between the distal shaft and the base shaft in the catheter shown in FIG. 1, FIG. 4 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 6 is a cross-sectional view taken along the line C-C of FIG. 1, FIG. 7 is an enlarged cross-sectional view of the proximal end portion of the catheter shown in FIG. 1, and FIG. FIG. 2 is an enlarged cross-sectional view of the distal end portion of the catheter shown in FIG. 1.
The catheter 1 of the present invention has a base shaft 2, a distal shaft 3, and an inner tube 4 disposed in the distal shaft 3, and in the vicinity of the proximal end of the distal shaft 3, the inner tube 4 and the proximal shaft. 2 and the distal shaft lumen 31 formed between the inner surface of the distal shaft 3 and the outer surface of the inner tube 4 and the proximal shaft lumen formed in the proximal shaft 2. The base end portion of the distal shaft 3, the distal end portion of the base shaft 2, and the inner tube 4 are fused together in a state where 21 is communicated. The catheter 1 includes a lumen securing tube 5 having a proximal end located in the proximal shaft lumen 21 and a distal end located in the distal shaft lumen 31.
The catheter 1 of the present invention is a so-called rapid exchange type.

The catheter 1 includes a distal shaft 3, a base shaft 2, an inner tube 4 and a balloon 6. The tip shaft 3, the base shaft 2, and the inner tube 4 are joined as shown in FIGS.
As shown in FIGS. 1, 3 to 8, the distal shaft 3 is a tube body penetrating from the distal end to the proximal end, into which the inner tube 4 can be inserted. The tip shaft 3 has an outer diameter of 0.6 to 1.5 mm, preferably 0.8 to 1.1 mm, and an inner diameter of 0.5 to 1.4 mm, preferably 0.7 to 1.0 mm. .
As shown in the figure, the inner tube 4 is a tube body penetrating from the distal end to the proximal end, and when inserted into the distal shaft 3, the inner tube 4 has a distal end portion as shown in FIG. A predetermined length protrudes from the tip of the shaft 3. The inner tube 4 has an outer diameter of 0.35 to 1.0 mm, preferably 0.45 to 0.8 mm, and an inner diameter of 0.2 to 0.9 mm, preferably 0.35 to 0.7 mm. . Moreover, although the protrusion length from the front-end | tip of the front-end | tip shaft 3 of the inner tube 4 changes with lengths of the balloon to be used, it is about 5-100 mm, Preferably it is 10-60 mm.

  The material for forming the inner tube 4 and the tip shaft 3 is preferably a material having a certain degree of flexibility. For example, polyamide, polyester, polyamide elastomer, polyester elastomer, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer). , Ethylene-vinyl acetate copolymers, and cross-linked or partially cross-linked products thereof), thermoplastic resins such as polyvinyl chloride and polyurethane. The inner tube 4 may be formed of a single resin material. However, in order to improve the slidability of the guide wire, the inner layer is made of a low friction material such as polyethylene or fluororesin. Preferably, the outer layer is made of a material compatible with the material of the base shaft and the tip shaft. In this case, the inner layer forming material may not be compatible with the material of the base shaft and the tip shaft.

  As shown in FIGS. 1, 3 to 7, the base shaft 2 is a tube body penetrating from the distal end to the proximal end, and includes a hub 7 fixed to the proximal end. The distal end portion of the base shaft 2 is joined to the proximal end portion of the distal shaft 3. As shown in FIGS. 3 to 7, a rigidity imparting body 8 is inserted into the base shaft 2, and the rigidity imparting body 8 is fixed to the hub 7 of the base shaft 2 at the base end, , Protruding from the tip of the base shaft 2 and extending into the tip side shaft 3. In this embodiment, the distal end portion of the rigidity imparting body 8 reaches the inner tube 4 of the distal end side shaft 3, in other words, the balloon expanding lumen 31.

The rigidity imparting body 8 extends from the proximal end of the base shaft 2 to the distal end side. Further, the rigidity imparting body 8 is fixed to the base shaft 2 or the hub 7 only at the base end so as not to obstruct the bending of the catheter 1, and other parts, specifically, the base end of the base shaft 2. It is not fixed to any of the inside except the part, the inner tube 4 and the tip shaft 3. The rigidity imparting body 8 prevents the base shaft 2 from being bent at the bent portion and causing the base shaft 2 to meander in the blood vessel without significantly reducing the flexibility of the base shaft 2. The rigidity imparting body 8 is preferably formed of a linear body. The linear body is preferably a metal wire, and is preferably an elastic metal such as stainless steel having a wire diameter of 0.05 to 1.5 mm, preferably 0.1 to 1.0 mm, a superelastic alloy, etc. Is a high-strength stainless steel for springs and a superelastic alloy wire.
The superelastic alloy here is generally called a shape memory alloy, and exhibits superelasticity at least at a living body temperature (around 37 ° C.). Particularly preferably, a Ti-Ni alloy of 49-53 atomic% Ni, a Cu-Zn alloy of 38.5-41.5 wt% Zn, a Cu-Zn-X alloy of 1-10 wt% X (X = Be, A superelastic alloy such as a Si-Sn, Al, Ga), Ni-Al alloy of 36-38 atomic% Al is preferably used. In particular, the above Ti—Ni alloy is desirable. Further, a Ti—Ni—X alloy (X = Co, Fe, Mn, Cr, V, Al, Nb, W, B, etc.) in which a part of the Ti—Ni alloy is substituted with 0.01 to 10.0 atomic% X Or a Ti—Ni—X alloy (X = Cu, Pb, Zr) in which a part of the Ti—Ni alloy is substituted with 0.01 to 30.0 atomic% X, and cold By selecting the processing rate or / and the final heat treatment conditions, the mechanical properties can be appropriately changed. Further, the mechanical characteristics can be appropriately changed by selecting the cold work rate and / or the final heat treatment conditions using the Ti—Ni—X alloy.

The base shaft 2 fixes the rigidity imparting body 8 at the base end, and the base end of the base shaft 2 is fixed to the tip end of the hub 7. A kink prevention tube 71 is attached to the outer surface of the boundary portion between the hub 7 and the base shaft 2 so as to cover the both. The base end portion of the hub 7 serves as a connection portion 72 of a balloon expansion fluid injection device (for example, a syringe).
The base shaft 2 has an outer diameter of 0.5 to 1.5 mm, preferably 0.6 to 1.3 mm, and an inner diameter of 0.3 to 1.4 mm, preferably 0.5 to 1.2 mm. .
As a material for forming the base shaft 2, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.), polyvinyl chloride, and the like. Further, thermoplastic resins such as polyamide, polyamide elastomer, polyester, polyester elastomer, polyimide, and polyurethane, silicone rubber, latex rubber, and the like can be used, and the above thermoplastic resins are preferable. Further, as a material for forming the base shaft 2, a metal tube such as a stainless steel tube or a superelastic alloy tube may be used.

In addition, since the proximal end portion of the distal shaft 3, the proximal end portion of the inner tube 4, and the distal end portion of the base shaft 2 are fused to form the joint portion 10, at least the proximal end portion of the distal shaft 3 and the inner tube 4 It is preferable that the base end part and the front end part of the base shaft 2 are formed of a thermoplastic resin. In particular, these portions are preferably formed of a thermoplastic resin having compatibility that can be fused to each other.
Specifically, at least the tip portion of the base shaft 2 is formed of a thermoplastic resin that can be heat-sealed with the tip shaft and the inner tube shaft. The whole may be formed of a thermoplastic resin. Further, only the base end side portion of the base shaft may be made of metal. Further, the base shaft is preferably one having higher rigidity than the tip shaft. In order to increase the rigidity of the base shaft, a filler or the like may be mixed with the resin for forming the base shaft. The tip shaft is preferably formed of a material that is more flexible than the base shaft. At least the base end portion of the tip shaft is formed of a thermoplastic resin that can be heat-sealed to the base shaft. As described above, at least the outer portion of the base end portion of the inner tube is formed of a thermoplastic resin that can be heat-sealed with the base shaft and the tip shaft.

In the catheter 1 of the present invention, the inner tube 4 and the distal end portion of the base shaft 2 are arranged substantially in parallel near the proximal end of the distal shaft 3, and the inner surface of the distal shaft 3 and the outer surface of the inner tube 4 are In the state where the tip shaft lumen 31 formed between the base shaft 2 and the base shaft lumen 21 formed in the base shaft 2 communicate with each other, the base end of the tip shaft 3, the tip of the base shaft 2, and the inner tube 4 is fused. Further, the catheter 1 includes a lumen securing tube 5 having a proximal end located in the base shaft lumen 21 and a distal end located in the distal shaft lumen 31.
As shown in FIGS. 2 and 3, the joint portion 10 between the distal end portion of the base shaft 2 and the proximal end portion of the distal shaft 3 is connected to the inner tube 4 inserted into the distal shaft from the proximal end of the distal shaft 3. The proximal end is exposed, and the proximal end opening of the inner tube 4 forms a guide wire introduction rod 42. Moreover, the inlet 42 is formed diagonally as shown in FIG.

As shown in FIGS. 2 and 3, the tip of the base shaft 2 is formed obliquely. The distal end of the base shaft 2 does not penetrate into the distal shaft 3, is located outside the distal shaft 3, and a part 2 a of the inner surface of the distal end portion of the base shaft 2 is the base of the distal shaft 3. It is in contact with a part 3a of the outer surface of the end. The tip shaft 3 and the base shaft 2 are fused in a liquid-tight manner at the contact surfaces 2a and 3a described above. Further, a part 2 b of the outer surface of the distal end portion of the base shaft is in contact with a part 4 a of the outer surface of the base end part of the inner tube 4. The inner tube 4 and the base shaft 2 are fused in a liquid-tight manner at the contact surfaces 2b and 4a described above.
In the catheter 1 of this embodiment, as shown in FIG. 2 and FIG. 3, the lumen securing tube 5 has a proximal end portion penetrating into the base shaft 2 and a proximal end portion of the base shaft 2. The distal end is located at the proximal end side by a predetermined distance from the distal end, the distal end portion enters the distal shaft 3, and the distal end is located at the distal end side by a predetermined distance from the proximal end of the distal shaft 3. The lumen securing tube 5 is parallel to the proximal end portion of the inner tube 4 and is in contact with a part of the outer surface of the inner tube 4 and a part of the inner surface of the distal shaft 3 in the proximal end portion of the distal shaft 3. The lumen 21 of the base shaft 2 and the lumen 31 of the tip shaft 3 communicate with each other through the lumen securing tube 5.

By providing the lumen securing tube 5, the distal shaft lumen 31 is prevented from collapsing at the joint portion 10 between the proximal end of the distal shaft 3 and the distal end of the base shaft 2, and injected into the base shaft lumen 21. The flow of the fluid to the tip shaft lumen 31 is made good. The lumen securing tube 5 is preferably harder or less crushed than the inner tube 4 and the tip shaft 3.
Further, the resin material of the tip shaft 3 melted at the time of fusion flows into the portion 32 formed between the base end portion of the inner tube 4 and the tip of the base shaft 2, and the portion is in a liquid-tight state.

  As shown in FIG. 4, which is a cross-sectional view taken along the line AA in FIG. 2, a guide wire introduction rod 42 is formed by the proximal end opening of the inner tube 4 in the joint portion 10. The lumen securing tube 5 is arranged. Further, the rigidity imparting body 8 passes through the lumen securing tube 5. Further, as shown in FIG. 5 which is a sectional view taken along the line BB of FIG. 2, the catheter 1 at the distal end portion of the joint 10 is inserted into the distal shaft 3 and the distal shaft 3 and is substantially parallel. The inner tube 4 and the lumen securing tube 5 are configured. In the illustrated example, the lumen securing tube 5 is pressed against the inner surface of the distal shaft 3 and the outer surface of the inner tube 4 and is slightly crushed, specifically, a shape in which the cross section is elliptical. It has become. In addition, it is not limited to such a thing, You may hold | maintain perfect circle shape. Further, as shown in FIG. 6, which is a cross-sectional view taken along the line CC of FIG. 1, the catheter 1 at the distal end portion of the distal shaft includes a distal shaft 3, an inner tube 4 inserted into the distal shaft 3, and a distal shaft. It is configured by the rigidity imparting body 8 located in the inner cavity 31.

In addition, the distal end of the lumen securing tube 5 is positioned closer to the distal end side of the catheter than the distal end of the joint portion (the proximal end portion of the distal shaft, the distal end portion of the base shaft, and the fusion portion of the inner tube) 10. preferable. That is, it is preferable that the distal end portion of the tube 5 protrudes from the joint portion 10. In addition, as shown in FIG. 3, the proximal end of the lumen securing tube 1 is preferably located closer to the proximal end of the catheter than the proximal end of the joint 10. That is, it is preferable that the base end portion of the tube 5 protrudes from the joint portion 10.
The lumen securing tube 5 has a length of 0.1 mm to 200 mm, more preferably 5 to 20 mm, and an inner diameter of 0.10 to 1.0 mm, more preferably 0.20 to 0.45 mm. The outer diameter is 0.11 to 1.2 mm, more preferably 0.25 to 0.50 mm. Further, the penetration length of the lumen securing tube 5 into the base shaft is 0.1 to 100 mm, preferably 2 to 10 mm, and the penetration length of the lumen securing tube 5 into the distal shaft is 0. 1 to 200 mm, preferably 2 to 20 mm. In addition, it is preferable that the lumen securing tube be appropriately thin in consideration of ensuring that the inner diameter of the lumen is sufficiently wide without being broken when inserted into the base shaft and the distal shaft. Specifically, about 5 to 100 μm is preferable.

  The lumen securing tube 5 is preferably formed of a material having a higher melting point or a thermosetting resin material than the forming material of the base shaft 2, the tip shaft 3 and the inner tube 4. The material having a high melting point is different depending on the material used for the base shaft 2, the tip shaft 3 and the inner tube 4, but it is preferable to use a material having a melting point higher by 100 ° C. or more than these resin materials. Examples of such heat-resistant resin include thermoplastic polyimide, polycarbonate, acrylic resin, thermoplastic fluororesin, and thermoplastic silicone resin. Thermosetting resins include thermosetting polyimide, PEEK (polyether ether ketone), PTFE (polytetrafluoroethylene), ETFE (ethylene tetrafluoroethylene), epoxy resin, diallyl phthalate resin, silicone resin, phenol resin, Saturated polyester resins, polyurethane resins, melamine resins, urea resins, etc. are conceivable. In particular, thermoplastic polyimide and thermosetting polyimide are preferable. If it is a polyimide tube, it will adhere | attach reliably with resin of the forming material of the front end shaft 3, the base part shaft 2, and the inner tube | pipe 4 by the favorable adhesiveness which polyimide itself has.

Further, the lumen securing tube may be a metal tube or a metal coil body. The metal used in this case is preferably an elastic metal such as stainless steel, a superelastic alloy, or the like. As the stainless steel and the superelastic alloy, the same materials as described in the rigidity imparting body can be preferably used.
Furthermore, the lumen securing tube 5 may be provided with a slit or a recess (none of which is shown) extending in parallel or spirally in the axial direction. When providing this slit or a recessed part, you may provide them in the whole tube 5, and you may provide only in a front-end | tip part. By providing such slits or recesses, the tube 5 can be easily deformed (curved). Furthermore, by providing a slit or a recess at the distal end, there is no sudden change in physical properties at the distal end of the tube 5, and catheter kinking at the distal end of the tube 5 can be prevented. When the spiral slit is used, the flexibility may be changed by appropriately changing the slit pitch in the longitudinal direction of the lumen securing tube. When such a slit is provided, the shape and width are preferably such that the resin of the shaft material does not flow so much into the lumen 51 of the lumen securing tube when the shaft is melt-joined.

The catheter of this embodiment is a so-called balloon catheter, and the distal end of the inner tube 4 protrudes a predetermined length from the distal shaft 3, and the catheter 1 has a distal end portion 6 a fixed to the distal end portion of the inner tube 4. The proximal end portion 6 b is fixed to the distal end portion of the distal end shaft 3, and the balloon 6 that can be expanded by the fluid flowing into the distal end shaft lumen 31 is provided.
As shown in FIG. 8, the balloon 6 has a distal end side joint portion 6 a and a proximal end side joint portion 6 b, and the distal end side joint portion 6 a is fixed at a position slightly proximal to the distal end of the inner tube 4. The end side joint portion 6 b is fixed to the tip end of the tip shaft 3. The balloon 6 communicates with the balloon expansion lumen 31 in the vicinity of the proximal end portion.

  The balloon 6 is foldable, and can be folded on the outer periphery of the inner tube 4 when not expanded. The balloon 6 has a cylindrical portion (preferably a cylindrical portion) 6c having the same diameter. The substantially cylindrical portion may not be a complete cylinder, but may be a polygonal column. In the balloon 6, as described above, the distal end side joint 6a is fixed to the inner tube 4 and the proximal end side joint 6b is fixed to the distal end of the distal shaft 3 in a liquid-tight manner by an adhesive or heat fusion. . As shown in FIG. 8, the balloon 6 forms an expansion space 6 d between the inner surface of the balloon 6 and the outer surface of the inner tube 4. The expansion space communicates with the expansion lumen 31 at the entire periphery at the base end portion. Thus, since the proximal end of the balloon 6 communicates with the expansion lumen having a relatively large volume, the expansion fluid can be reliably injected into the balloon from the expansion lumen 31.

  As the material for forming the balloon 6, a material having a certain degree of flexibility is preferable. For example, thermoplastic resins such as polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyester elastomer, polyurethane, polyester, polyarylene sulfide, silicone, and the like Rubber, latex rubber, etc. can be used. In particular, a stretchable material is preferable, and the balloon 6 is preferably biaxially stretched having high strength and expansion force. As the size of the balloon 6, the outer diameter of the cylindrical portion (expandable portion 6c) when expanded is 1.5 to 5.0 mm, preferably 2.5 to 4.0 mm, and the length is 5 -50 mm, preferably 10-40 mm. Moreover, the outer diameter of the front end side joining portion 6a is 0.5 to 1.5 mm, preferably 0.7 to 1.0 mm, and the length is 1 to 5 mm, preferably 1.0 to 1.3 mm. . Moreover, the outer diameter of the base end side junction part 6b is 0.8-1.6 mm, Preferably it is 1.0-1.5 mm, Length is 1-5 mm, Preferably it is 2-4 mm. It may be a multilayer or a blend of the above materials.

In the inner tube 4, a distal-side contrast marker 17 is fixed to the outer surface at a position near the distal end of the cylindrical portion 6 c of the balloon 6. Similarly, a proximal contrast marker 18 is fixed to the outer surface of the inner tube 4 at a position near the proximal end inside the cylindrical portion 6 c of the balloon 6. The contrast marker is preferably formed of a radiopaque material (for example, gold, platinum, tungsten, or an alloy thereof, or a silver-palladium alloy). By doing in this way, the position of the front-end | tip and base end of the cylindrical part 6c of the balloon 6 can be confirmed by X-ray imaging.
In addition, the catheter of the present invention is not limited to the PTCA catheter as in the above-described embodiments, and can be applied to, for example, a living organ expansion catheter, a contrast catheter, a drug injection catheter, an ultrasonic catheter, and the like. it can. As a living organ dilatation catheter, for example, a catheter having substantially the same configuration as the PTCA catheter described above and a stent expandable by a balloon on the balloon is conceivable.

Next, the manufacturing method of the catheter of this invention is demonstrated using drawing.
FIG. 9 is an explanatory diagram for explaining the catheter manufacturing method of the present invention, and FIG. 10 is a cross-sectional view taken along the line DD of FIG.
The method of manufacturing a catheter of the present invention includes a base shaft, a distal shaft, and an inner tube disposed in the distal shaft, and the inner tube and the proximal shaft in the vicinity of the proximal end of the distal shaft. And a distal shaft lumen formed between the inner surface of the distal shaft and the outer surface of the inner tube, and a base shaft lumen formed in the base shaft. It is a method for manufacturing a catheter in which the proximal end portion of the distal shaft, the distal end portion of the proximal shaft, and the inner tube are fused in a communicating state.

The catheter manufacturing method of the present invention includes a base shaft 2 having at least a distal end portion made of a thermoplastic resin, a distal shaft 3 having at least a proximal end portion made of a thermoplastic resin, an inner tube 4 and a lumen securing portion. A step of preparing the tube 5; a step of arranging the inner tube 4 in the distal shaft; and a step of arranging the inner tube 4 and the distal end portion of the base shaft 2 substantially in parallel in the vicinity of the proximal end of the distal shaft 3; After the steps of disposing the lumen securing tube 5 so that the proximal end is located in the proximal shaft lumen 21 and the distal end is located in the distal shaft lumen 31, the distal end of the proximal shaft 2 after all the above steps And a fusion step of heating the base end portion of the tip shaft 3 and the inner tube 4 and fusing them.
First, a step of preparing a base shaft 2 having at least a distal end portion formed of a thermoplastic resin, a distal end shaft 3 having at least a base end portion formed of a thermoplastic resin, and an inner tube 4 is performed.
Material tubes such as a base shaft 2, a tip shaft 3, an inner tube 4, and a lumen securing tube 5 are prepared, and these are cut to a desired length. The dimensions and the like of each member are as described above. Next, one end of the inner tube 4 is cut obliquely to make the entire length a predetermined length. Moreover, the front-end | tip part of a base shaft is cut diagonally.

Next, a step of placing the inner tube 4 in the tip shaft 3 is performed. The inner tube 4 is inserted into the distal shaft 3 and is arranged so that the oblique cut end of the inner tube 4 is located at the proximal end of the distal shaft 3.
Next, as described above, the inner tube 4 and the distal end portion of the base shaft 2 are disposed substantially in parallel in the vicinity of the proximal end of the distal shaft 3 where the inner tube 4 is disposed, and the proximal end is the proximal shaft lumen. The step of arranging the lumen securing tube 5 so that the tip is located in the tip shaft lumen 31 is performed. In addition, this process may be performed before the process which arrange | positions the inner pipe | tube 4 in the front-end | tip shaft 3, or may be performed simultaneously. FIG. 9 shows a state where the steps so far are performed. 9 shows a catheter provided with a rigidity imparting body 8 that extends from the proximal end side of the base shaft lumen 21, passes through the lumen securing tube 5, and extends to the distal end side of the distal shaft lumen 31. For this reason, the step of preparing the rigidity imparting body 8 and the rigidity imparting body 8 extending from the proximal end side of the base shaft lumen 21 in the lumen securing tube 5 are prepared before the fusion process. The step of penetrating and arranging so as to extend to the distal end side of the distal shaft lumen 21 is performed. In addition, even if it is a manufacturing method of the catheter provided with such a rigidity imparting body 8, the rigidity imparting body 8 may be inserted after the joining part 10 is fused.
And after all the above-mentioned processes, the fusion process which heats the tip part of base shaft 2, the tip part of tip shaft 3, and inner tube 4 and fuses these is performed.

  As shown in FIG. 10, which is a cross-sectional view taken along the line D-D in FIGS. 9 and 9, a predetermined region before and after the proximal end of the distal shaft 3 and the distal end portion of the base shaft 2 is encapsulated with a heat shrinkable tube 9. The predetermined region is heated together with the contraction tube, the heat contraction tube is contracted and brought into close contact with the joint portion 10, and the distal end portion of the base shaft 2, the proximal end portion of the distal shaft 3 and the inner tube 4 are fused. The heating temperature in the fusing step is performed below the melting point of the material for forming the lumen securing tube 5. In the manufacturing method of the present invention, since the lumen securing tube 5 is arranged when performing the fusion process, it is not necessary to put a cored bar in the base shaft and the tip shaft, and the manufacturing is easy. . The length of the heat-shrinkable tube 9 (the length of the predetermined region) is 1 to 100 mm, preferably 5 to 20 mm. The lumen securing tube 5 is preferably longer than the heat-shrinkable tube 9 and has a portion where the distal end portion and the proximal end portion of the lumen securing tube 5 are not heated. This fusion process is not limited to heat fusion, and may be performed by high frequency fusion or ultrasonic fusion.

  The heat-shrinkable tube 9 is created by creating a tube with an inner diameter smaller than the joint 10 and expanding it in the radial direction. As a material for forming the heat-shrinkable tube 9, polyolefins such as polyethylene and polypropylene, EAA (ethylene-acrylic acid copolymer), EVA (ethylene-vinyl acetate copolymer), silicone resin, fluorine resin, and the like can be used. In particular, those incompatible with the forming material of the tip shaft, inner tube, and base shaft to be used are used. And after the fusion | melting of the junction part 10 is completed, a heat contraction tube is removed.

The heat shrinkable tube 9 is preferably shorter than the lumen securing tube 5. Furthermore, as shown in FIG. 9, the distal end of the lumen securing tube 5 is preferably located closer to the distal end side than the distal end of the heat shrinkable tube 9. By doing so, the distal shaft lumen 31 is not crushed by the heat-shrinkable tube contracting force, and the lumen 31 is ensured. Furthermore, the proximal end of the lumen securing tube 5 is preferably located closer to the proximal end than the proximal end of the heat shrinkable tube 9.
Further, when the catheter includes a balloon 6 as shown in FIGS. 1 and 8, the distal end portion 6 a is fixed to the distal end portion of the inner tube 4, and the proximal end portion 6 b is fixed to the distal end portion of the distal end shaft 3. A balloon fixing step is performed. The balloon fixing step is performed by fusion (specifically, heat fusion, high frequency fusion, ultrasonic fusion), adhesion, ligation using a thread, or the like. Further, when the contrast markers 17 and 18 as shown in FIG. 8 are provided, this marker attaching step is performed before the balloon fixing step.

Then, the hub 7 is fixed to the base end of the base shaft 2.
More specifically, between the tip shaft 3 made of polyamide elastomer and the inner tube 4 whose outer layer is a mixture of polyamide elastomer and maleic anhydride-modified low-density polyethylene and whose inner layer is high-density polyethylene, the inner diameter is 0.40 mm. A base tube 2 made of filler-filled nylon 12 and a rigidity imparting body 8 are inserted as shown in FIGS. 9 and 10 by inserting a polyimide tube 5 having an outer diameter of 0.43 mm and a length of 15 mm, and then cutting the tip obliquely in advance. set. Then, the heat shrinkable tube 9 is put on the joint portion. In this state, heat is applied from above the heat shrinkable tube. The tip shaft 3, the inner tube 4, and the base shaft 2 are heated and melted and fused. Furthermore, the heat-shrinkable tube 9 is heated and heat-shrinks, and the outer diameter of each joint portion is regulated. At this time, the polyimide tube 5 is not affected by heat, and the distal shaft lumen 31 and the base shaft lumen 21 (expansion lumen) are maintained.

FIG. 1 is a front view of an embodiment in which the catheter of the present invention is applied to a PTCA catheter. FIG. 2 is an enlarged view of the vicinity of the joint between the distal shaft and the base shaft in the catheter shown in FIG. FIG. 3 is an enlarged cross-sectional view of the vicinity of the joint between the distal shaft and the base shaft in the catheter shown in FIG. 4 is a cross-sectional view taken along line AA in FIG. 5 is a cross-sectional view taken along line BB in FIG. FIG. 6 is a cross-sectional view taken along the line CC of FIG. 7 is an enlarged cross-sectional view of the proximal end portion of the catheter shown in FIG. FIG. 8 is an enlarged sectional view of the distal end portion of the catheter shown in FIG. FIG. 9 is an explanatory diagram for explaining the catheter manufacturing method of the present invention. 10 is a cross-sectional view taken along the line DD of FIG.

Explanation of symbols

1 Catheter 2 Base shaft 3 Tip shaft 4 Inner tube 5 Lumen securing tube 6 Balloon 7 Hub 8 Stiffener 9 Heat shrinkable tube

Claims (15)

A base shaft, a tip shaft, and an inner tube disposed in the tip shaft, and the inner tube and the tip of the base shaft are arranged substantially in parallel near the base end of the tip shaft. And the distal shaft in a state where the distal shaft lumen formed between the inner surface of the distal shaft and the outer surface of the inner tube communicates with the base shaft lumen formed in the base shaft. A proximal end of the base shaft, the distal end of the base shaft, and the inner tube, wherein the catheter has a proximal end located in the base shaft lumen and a distal end in the distal shaft lumen. A catheter comprising a lumen securing tube located. The tip of the base shaft does not penetrate into the tip shaft, and a part of the inner surface of the tip of the base shaft is in contact with a part of the outer surface of the base end of the tip shaft The catheter according to claim 1, which is a catheter. The catheter according to claim 1 or 2, wherein the lumen securing tube is formed of a material having a higher melting point or a thermosetting resin material than a material for forming the distal shaft, the inner tube, and the base shaft. The catheter according to claim 3, wherein the material having a high melting point or the thermosetting resin material is any one of thermoplastic polyimide, thermosetting polyimide, and metal. The catheter according to any one of claims 1 to 4, wherein the lumen securing tube includes a slit or a recess extending in parallel or spirally in the axial direction. The catheter according to any one of claims 1 to 4, wherein the lumen securing tube is a coil body. The distal end of the inner tube protrudes a predetermined length from the distal shaft, and the catheter has a distal end fixed to the distal end of the inner tube, a proximal end fixed to the distal end of the distal shaft, The catheter according to any one of claims 1 to 6, further comprising a balloon expandable by a fluid flowing into the distal shaft lumen. The catheter according to any one of claims 1 to 7, wherein the inner tube includes a guide wire insertion opening that opens at a proximal end of the distal shaft or in the vicinity thereof. 9. The catheter according to claim 1, further comprising a rigidity imparting body extending from a proximal end side of the base shaft lumen, penetrating the lumen securing tube, and extending toward a distal end side of the distal shaft lumen. Catheter according to any one of the above. 10. The distal end of the lumen securing tube is located closer to the distal end of the catheter than the proximal end of the distal shaft, the distal end of the proximal shaft, and the distal end of the fused portion of the inner tube. The catheter according to any one of the above. The proximal end of the lumen securing tube is located closer to the proximal end of the catheter than the proximal end of the distal shaft, the distal end of the base shaft, and the proximal end of the fused portion of the inner tube. The catheter according to any one of 1 to 10. A base shaft, a tip shaft, and an inner tube disposed in the tip shaft, and the inner tube and the tip of the base shaft are arranged substantially in parallel near the base end of the tip shaft. And the distal shaft in a state where the distal shaft lumen formed between the inner surface of the distal shaft and the outer surface of the inner tube communicates with the base shaft lumen formed in the base shaft. A method of manufacturing a catheter in which the proximal end of the base shaft, the distal end of the base shaft and the inner tube are fused,
Preparing a base shaft having at least a distal end portion formed of a thermoplastic resin, a tip shaft having at least a proximal end portion formed of a thermoplastic resin, an inner tube, and a lumen securing tube;
Placing the inner tube in the tip shaft;
In the vicinity of the proximal end of the distal shaft, the inner tube and the distal end portion of the base shaft are arranged substantially in parallel, the proximal end is located in the proximal shaft lumen, and the distal end is in the distal shaft lumen. Arranging the lumen securing tube to be positioned;
A catheter manufacturing method comprising: a fusion step of fusing the distal end portion of the base shaft, the proximal end portion of the distal shaft, and the inner tube after all the steps described above. The catheter includes a rigidity imparting body extending from a proximal end side of the base shaft lumen, penetrating the lumen securing tube, and extending to a distal end side of the distal shaft lumen, and the method for manufacturing the catheter Preparing the rigidity-imparting body and, prior to the fusing step, passing the rigidity-imparting body extending from the proximal end side of the base shaft lumen through the lumen securing tube, The method for manufacturing a catheter according to claim 10, wherein the step of arranging the catheter so as to extend toward the distal end side is performed. In the fusing step, a predetermined region before and after the proximal end of the distal shaft and the distal end portion of the base shaft is encapsulated by a heat-shrinkable tube, the predetermined region is heated together with the heat-shrinkable tube, and the heat-shrinkable tube is contracted. The method for manufacturing a catheter according to claim 12 or 13, wherein the catheter is bonded to the distal end portion of the base shaft, the proximal end portion of the distal shaft, and the inner tube. As the heat shrinkable tube, a tube shorter than the lumen securing tube is used, and in the fusing step, the distal end of the lumen securing tube is located on the distal side of the distal end of the heat shrinkable tube, and the lumen securing is performed. The catheter manufacturing method according to claim 14, wherein the catheter is performed in a state where the proximal end of the tube for use is located closer to the proximal end than the proximal end of the heat shrinkable tube.

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