JP2001137348A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter which does not kink at a joint part between a hard tube and a soft tube. SOLUTION: A hard tube 21 is formed of an alloy of nickel and titanium with external diameter of 0.6 mm, internal diameter of 0.4 mm and length of 860 mm, and on the tip thereof, a slit 24 is spirally formed by being cut at a short pitch toward the tip. The part on which the slit 24 is formed is inserted into a soft tube 22 which is formed of composite resin so as to have external diameter of 0.9 mm, internal diameter of 0.4 mm and length of 200 mm. Accordingly, in the joint part 23, hardness changed continuously from the hard tube 21 side to the soft tube 22 side. Thus, the joint part 23 does not kink when the catheter is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catheter used for diagnosis or treatment of blood vessels and organs.

[0002]

2. Description of the Related Art A catheter is used to insert a thin tube into a body to inject a drug solution or treat a lesion. A PTCA balloon catheter or a transcatheter catheter used for percutaneous transluminal coronary angioplasty (PTCA) is used. A special catheter called a PTA balloon catheter used for percutaneous transluminal angioplasty (PTA) is used by being inserted into a guiding catheter previously introduced into a blood vessel through a sheath, so that it is extremely thin. Tubes are required. On the other hand,
If the tube made of synthetic resin is thin, the strength will be insufficient and practicality will be lost, so even if it is thin, the tube must be made of metal to secure the desired strength,
The tip cannot be supple. Therefore, in this type of balloon catheter, as shown in FIGS. 7A and 7B, the distal end of the metal hard tube 41 is inserted into the synthetic resin soft tube 42 so that The configuration in which the tube 42 is added is adopted.

[0003]

However, in the balloon catheter 40 as described above, the push-pull operation (catheter control) must be repeated at hand to introduce the balloon provided at the distal end to the lesion. At the joint of the two tubes, the hardness changes extremely at the boundary 43 between the portion where the hard tube is inserted into the soft tube and the portion of the soft tube alone, and buckling (kinking) occurs at the boundary 43. , It will bend. Once bent, the lumen of the tube is closed and the product function cannot be ensured, so that the operation cannot be continued. Accordingly, an object of the present invention is to provide a catheter that does not kink at a joint between a hard tube and a soft tube.

[0004]

According to the first aspect of the present invention, a flexible tube made of a synthetic resin is added to a tip of a hard tube made of a metal, so that the tip of the tube is made flexible. In a catheter with a stiffness, the distal end of the hard tube is formed so as to become gradually thinner toward the distal end, and all of the thinned portion is inserted into the soft tube. It is added by. According to a second aspect of the present invention, which is another means for achieving the above object, a spiral slit or groove is cut or formed continuously or intermittently at the tip of the hard tube, and the slit or groove is formed. Are added by inserting all of the portions formed with into the soft tube. In addition, if the pitch interval of the spiral is narrowed toward the distal end side as in the third aspect, the catheter is more resistant to kinking. Further, in the configuration of the invention described in claim 4, a plurality of slits or grooves are cut continuously or intermittently from the tip of the hard tube in parallel with the axis, and all the portions where the slits or grooves are formed are formed. It is added by inserting it into a soft tube. In addition, if the width of the slit or groove is increased toward the distal end as described in claim 5,
It becomes a catheter that is more difficult to kink. And claim 6
In the configuration of the invention described in the above, a C-shaped slit or groove is cut in the distal end portion of the hard tube in the circumferential direction at an interval in the axial direction, and all of the portion where the slit or groove is formed are soft. It was added by inserting it into the tube. In addition, if the distance between the slits or grooves is made closer to the distal end side as described in claim 7, the catheter is more resistant to kinking.

[0005]

[Embodiment 1] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a rapid exchange type PTCA balloon catheter 10 according to the present invention. FIG. 2 (a) is an enlarged view of a distal end portion of a hard tube used in the balloon catheter 10, and FIGS. () Is a cross-sectional view of a joint portion 13 between the hard tube 11 and the soft tube 12. The balloon catheter 10 is obtained by inserting the distal end of a hard tube 11 made of metal into a soft tube 12 made of a synthetic resin, and connecting the base end of the hard tube 11 to a cylindrical pressurizer 14. . The soft tube 12 has a balloon 15 at the tip and a guide wire 1.
A wire lumen (not shown) for passing 6 is formed from the side to the tip through the inside of the balloon. Hard tube 11 is made of nickel-titanium alloy and has an outer diameter of 0.6 mm.
・ The inner diameter is 0.4mm and the length is 860mm.
The tip is gradually thinned toward the tip, and has a tapered cross section (FIG. 2a). The tapered portion (reinforcement portion 13) has an outer diameter of 0.9 mm and an inner diameter of 0.4 m.
m. It is inserted into a soft tube 12 formed to a length of 200 mm (FIG. 2b). Therefore, addition part 1
In No. 3, the hardness changes continuously from the hard tube 11 side to the soft tube 12 side.

Next, the operation of the above embodiment will be described. FIG. 3 is an explanatory view showing a state where the balloon catheter 10 is inserted into a coronary artery. First, the guiding catheter 17 is inserted through a sheath introducer (not shown) inserted into the blood vessel, and is pushed and pulled to operate the coronary artery entrance 18.
To introduce. Next, the guide wire 16 is inserted into the wire lumen of the balloon catheter 10 and the guiding catheter 17, and introduced from the coronary artery entrance 18 through the lesion 19 to a peripheral site. Subsequently, the balloon catheter 10 is introduced to the lesion 19 along the guide wire 16 while performing a push-pull or twist operation.
In the process, a compressive force and a shearing force are applied to the replenishing part 13 from various directions, but since the hardness of the replenishing part 13 continuously changes from the hard tube 11 side to the soft tube 12 side, their stress is reduced. It is dispersed throughout the replenishing portion 13 and does not kink (FIG. 2C). Balloon 15
When the patient reaches the lesion 19, the balloon 5 is expanded by the pressurizer 14, and the lesion 19 is treated.

[Embodiment 2] Another embodiment of the present invention will be described with reference to the drawings. FIG. 4A is an enlarged view of a distal end of a hard tube used for the balloon catheter 20,
FIGS. 2B and 2C are explanatory views showing a part of a refill portion 23 between the hard tube 21 and the soft tube 22 in a partially cut manner. The balloon catheter 20 is obtained by inserting a distal end of a hard tube 21 made of a metal into a soft tube 22 made of a synthetic resin, and connecting the base end of the hard tube 21 to a cylindrical pressurizer. The soft tube 22 has a balloon at the tip, and a wire lumen for passing a guide wire is formed from the side to the tip through the inside of the balloon. Hard tube 21
Is a nickel-titanium alloy with an outer diameter of 0.6 mm and an inner diameter of 0.4
mm and a length of 860 mm, and a slit 24 is formed in the distal end portion in a spiral shape at a shorter pitch toward the distal end (FIG. 4).
a), the tip end has greater flexibility. Then, the portion where the slit 24 is formed as described above (the refill portion 2)
3) The outer diameter is 0.9 mm, the inner diameter is 0.4 mm, and the length is 200
It is inserted into a flexible tube 22 made of synthetic resin having a thickness of 2 mm (FIG. 4b). Therefore, the additional portion 2
In No. 3, the hardness changes continuously from the hard tube 21 side to the soft tube 22 side.

Next, the operation of the above embodiment will be described. The balloon catheter 20 is inserted into a blood vessel by a known method, and is introduced to a lesion while performing a push-pull or twist operation. In the process, a compressive force and a shearing force are applied to the replenishing portion 23 from various directions. However, since the hardness of the replenishing portion 23 continuously changes from the hard tube 21 side to the soft tube 22 side, the first embodiment differs from the first embodiment. Similarly, those stresses are dispersed and do not kink (FIG. 4c).

[Embodiment 3] Still another embodiment of the present invention will be described. FIG. 5A shows a balloon catheter 3.
FIG. 2 is an enlarged view of a distal end portion of a hard tube used in FIG. 0, and FIGS. 2B and 2C are explanatory views showing a partially cut-out portion of an extension 33 between the hard tube 31 and the soft tube 32. The balloon catheter 30 is obtained by inserting the distal end of a metal hard tube 31 into a soft tube 32 made of synthetic resin, and connecting the base end of the hard tube 31 to a cylindrical pressurizer. . The soft tube 32 has a balloon at the tip, and a wire lumen for passing a guide wire is formed from the side to the tip through the inside of the balloon. Hard tube 31
Is a nickel-titanium alloy having an outer diameter of 0.6 mm and an inner diameter of 0.1 mm.
4 mm and a length of 860 mm, and slits 34, 34,... Are cut in parallel from the leading end thereof in the axial direction, and the leading end is divided into a plurality of parts (FIG. 5).
a). The slits 34, 34,... And the above-mentioned divided part (reinforcement part 33)
But outer diameter 0.9mm, inner diameter 0.4mm, length 200mm
(FIG. 5b).

In the balloon catheter 30, since the distal end of the hard tube is divided into a plurality of parts by the slits 34, 34,..., The stress applied to the replenishment part 33 at the time of catheter control is reduced by the slits 34, 34,.
And kink does not occur as in the first and second embodiments (FIG. 5c).

It should be noted that the present invention is not limited to the above three embodiments at all,
The shape, length, shape of the slit, and the like can be appropriately changed without departing from the spirit of the present invention. For example, the shape of the distal end portion of the hard tube is described as a straight taper shape in the first embodiment, but the present invention is not limited to this. For example, a curved taper shape as shown in FIG. In the above embodiments 2 and 3, spiral slits and vertically split slits have been described as to slits formed in the distal end portion of the hard tube. In addition, slits are formed in a C shape as shown in FIG. However, it is also conceivable to use a wheel-cut type that leaves a bridge in a spiral shape. further,
In all the embodiments, the form of the slit “penetrated from the outside to the inside of the tube” has been described, but a groove may be formed on the outside or inside of the tube without penetrating. In addition, the present invention can be implemented in any form in which a slit or a groove is cut into an arbitrary portion and an arbitrary depth at a distal end portion of a hard tube thinned into various shapes.

As the material for the hard tube, a metal material such as stainless steel and amorphous material can be used as appropriate in addition to the titanium material. As the material for the soft tube, silicon rubber, polyacetate and the like can be suitably used. Further, it is also recommended that a fiber material such as graphite fiber be internally or buried in the tube to improve kink resistance as required. In all of the first to third embodiments, the balloon catheter in the PTCA procedure has been described. However, the present invention can be applied to the PTA procedure, and can be applied not only to the rapid exchange type but also to the over-the-wire type and other balloon catheters. Further, the present invention can be applied to a catheter in which a stent or the like is placed in addition to a balloon.

[0013]

According to the present invention, it is possible to obtain a catheter which does not kink at the joint between the hard tube made of metal and the soft tube made of synthetic resin.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a balloon catheter.

FIG. 2 is an enlarged view of a tip portion of a hard tube, and a cross-sectional view of a portion where a hard tube and a soft tube are added.

FIG. 3 is an explanatory view showing a state where a balloon catheter is inserted into a coronary artery.

FIG. 4 is an enlarged view of a distal end portion of a hard tube, and an explanatory view showing a partially cut-out portion of an extension between a hard tube and a soft tube.

FIG. 5 is an enlarged view of a distal end portion of a hard tube and an explanatory view showing a partially cut-out portion of an extension between a hard tube and a soft tube.

FIG. 6 is an enlarged view of a distal end portion of a hard tube.

FIG. 7 is an enlarged view of a tip portion of a conventional hard tube, and a cross-sectional view of a joint portion between a hard tube and a soft tube.

[Explanation of symbols]

10. Balloon catheter, 11 Hard tube,
12 ·································································· 14
Pressurizer, 15 balloon, 16 guide wire,
17 guiding catheter, 18 coronary artery entrance, 19 lesion, 20 balloon catheter, 2
1 ... hard tube, 22 ... soft tube, 23 ...
Addition part, 24 slits, 30 balloon catheter, 31 hard tube, 32 soft tube, 33 addition part, 34 slit.

Claims (7)

[Claims] 1. A catheter in which a flexible tube made of synthetic resin is added to a distal end of a hard tube made of metal to make the distal portion flexible, and the distal portion of the hard tube is gradually moved toward the distal end. Formed to be thin,
A catheter which is added by inserting all the thin-walled portions into a soft tube. 2. A catheter in which a flexible tube made of synthetic resin is added to a tip of a hard tube made of metal to make the distal portion flexible, and a spiral slit or groove is formed at the tip of the hard tube. Is continuously or intermittently cut and formed, and all the portions where the slits are formed are inserted into a soft tube to extend the catheter. 3. The catheter according to claim 2, wherein the pitch interval of the spiral is narrowed toward the distal end. 4. A catheter in which a flexible tube made of synthetic resin is added to a tip of a hard tube made of metal to make the distal portion flexible, and a plurality of tubes are provided in parallel with the axis from the tip of the hard tube. A catheter in which slits or grooves are cut continuously or intermittently, and all of the slit-formed portions are inserted into a soft tube to be added. 5. The catheter according to claim 4, wherein the width of the slit or groove is increased toward the distal end. 6. A catheter in which a flexible tube made of synthetic resin is added to the tip of a hard tube made of metal to make the distal portion flexible, and a C-shaped member is formed circumferentially on the distal portion of the hard tube. A slit formed by cutting the slit or groove at an interval in the axial direction, and inserting all of the portion where the slit or groove is formed into a soft tube. 7. The catheter according to claim 6, wherein the distance between the slits or grooves is closer to the distal end.