WO2019221247A1 - Catheter and catheter manufacturing method - Google Patents

Abstract

Provided is a catheter having a novel structure which can inhibit braided wires that constitute braids from protruding from an end surface of a braided tube. A catheter 10 comprises a braided tube 20 in which reinforcing braids 22 are disposed. On at least one end of the braided tube 20: an end tube 28 is disposed so as to abut the axial direction end surface of the braided tube; and a cover tube 30 is fitted so as to extend over both the braided tube 20 and the end tube 28, and the cover tube is welded to the outer peripheral surfaces of both of the tubes 20, 28. The degree of welding of the cover tube 30 to the axial direction outer end portion of the end tube 28 is set to be greater than the degree of welding of the cover tube 30 to the abutting portion between the braided tube 20 and the end tube 28.

Description

Catheter and method for manufacturing catheter

The present invention relates to a catheter used in the medical field and a method for manufacturing the catheter, and more particularly to a catheter including a blade tube in which a tube made of a soft resin is reinforced with a wire material such as metal.

Conventionally, various catheters have been used in the medical field. For example, a catheter may be inserted into a body such as a blood vessel to inject a drug solution or the like, or blood or body fluid may be collected, or treatment or examination may be performed with a device inserted into the body through such a catheter. Further, in medical equipment such as dialysis machines, catheters are also used for configuring blood and chemical fluid channels outside the body.

As such a catheter, a soft resin tube is generally used, and can be inserted into the body along a curved blood vessel or the like. Further, since it is preferable to have sufficient pushability when inserted into a blood vessel or the like, a blade made of metal or the like is placed inside the cylinder wall as described in, for example, Japanese Patent Laid-Open No. 6-134034 (Patent Document 1). Have been proposed and used as a catheter.

Incidentally, as such a blade, a braided wire (braided sleeve) in which a wire having a relatively high rigidity such as metal is generally knitted is adopted. Therefore, when a long blade tube is cut into an appropriate length to produce a product, the braided wire exposed at the end face of the blade tube may protrude in the axial direction when the tube is bent. Therefore, in the conventional blade tube, it is proposed that a resin tube without a blade is fixed by extrapolation to the end portion of the blade tube and extends in the axial direction to cover the braided wire protruding from the end surface of the blade tube. .

JP-A-6-134034

However, extrapolation of the resin tube to the blade tube results in a substantial increase in diameter, making it difficult to employ a thick resin tube. With a thin resin tube, there is a risk that the protruding braided wire may penetrate. there were. Even if such a resin tube is extrapolated, the braided wire protruding from the end face of the blade tube is exposed in the resin tube, so that the exposed braided wire interferes with or deforms a filter or the like passing through the blade tube. It was difficult to obtain sufficient reliability.

Here, the problem to be solved by the present invention is to provide a catheter having a novel structure and a novel catheter manufacturing method capable of suppressing protrusion of the braided wire constituting the blade from the end face of the blade tube. is there.

First, the present inventors place an end tube in abutment with the axial end surface of the blade tube in series to prevent the braided wire (reinforcing blade) from protruding from the end surface of the blade tube so as to be covered with the end tube. I examined that. However, in order to connect the butted part of the blade tube and the end tube, for example, when trying to extrapolate the covering tube across both tubes, it is difficult to control the temperature in the welding process and to obtain stable quality. I understood.

Further examination of such a new problem revealed that the specific heat of the reinforcing blade made of metal or the like is orders of magnitude smaller than that of the tube material made of synthetic resin, while the heat conductivity of the tube material is that of the reinforcing blade. It was found that the cause is that it is an order of magnitude smaller than that of the tube material and the melting point of the tube material is extremely lower than that of the reinforcing blade. For this reason, when the connecting portion of the blade tube and the end tube that are butted against each other and are covered with the cover tube is heated during the welding process, the reinforcing blade is particularly formed at the butted portion of the blade tube and the end tube where the reinforcing blade is exposed. There was a risk that the blade tube would be melted and deformed locally due to excessively high temperature, and the reinforcing blade was exposed or protruded from the melted blade tube. On the other hand, if the heating temperature during the welding process is lowered in order to avoid such damage to the blade tube, sufficient welding strength can be stably obtained at the connecting portion of the blade tube covered with the cover tube and the end tube. It becomes difficult.

In view of the new problem as described above, the first aspect of the present invention made based on the new knowledge obtained by the present inventor is a catheter including a blade tube in which a reinforcing blade is disposed, An end tube is arranged with its end face in the axial direction being abutted at at least one end of the blade tube, and a cover tube is extrapolated across both the blade tube and the end tube, While being welded to the outer peripheral surface, the degree of welding of the covered tube to the axially outer end portion of the end tube is larger than the degree of welding of the covered tube to the butted portion of the blade tube and the end tube. It is what has been.

According to the catheter having a structure according to this aspect, the degree of welding of the covered tube that is extrapolated to the connection portion between the blade tube and the end tube is reduced at the abutting portion between the blade tube and the end tube, It becomes possible to reduce or avoid the high temperature and the accompanying damage to the blade tube during the welding process of the reinforcing blade exposed on the end face of the blade tube. On the other hand, the connection strength between the blade tube and the end tube can be ensured by welding the covered tube in a region where the butted portion between the blade tube and the end tube is displaced in the axial direction. Therefore, it is possible to reduce or avoid damage to the blade tube during welding while ensuring the welding strength for connecting the blade tube and the end tube.

A second aspect of the present invention is the catheter according to the first aspect, wherein the outer ends in the axial direction of the end tube and the covered tube are at equal positions in the axial direction.

According to the catheter having the structure according to this aspect, the end tube and the covered tube can be welded to each other at the outermost end in the axial direction, and therefore, the peeling of the end tube and the covered tube is more effective. Can be prevented.

A third aspect of the present invention is the catheter according to the first aspect, wherein the covered tube protrudes outward in the axial direction from the end tube.

According to the catheter having a structure according to this aspect, the end of the catheter can be formed only with a tube and can be configured more flexibly. In addition, stepped flexibility in the axial direction of the catheter is achieved by going from the extrapolated portion of the covered tube to the blade tube, through the extrapolated portion to the end tube that is not braided, and to the protruding portion of the covered tube. You can also have it.

A fourth aspect of the present invention is the catheter according to the first aspect, wherein the end tube protrudes outward in the axial direction from the covered tube.

According to the catheter having the structure according to this aspect, not only the stepwise flexibility in the axial direction is provided, but also the end tube having a smaller diameter than the covered tube protrudes outward in the axial direction to form the end of the catheter. Therefore, the insertion of the catheter can be improved.

A fifth aspect of the present invention is the catheter according to any one of the first to fourth aspects, wherein the covered tube is thinner than the blade tube.

The catheter having the structure according to this aspect can suppress an excessive increase in the outer diameter of the catheter, and can prevent the catheter from being deteriorated.

A sixth aspect of the present invention is the catheter according to any one of the first to fifth aspects, wherein the reinforcing blade is made of metal.

According to the catheter having the structure according to this aspect, since the reinforcing blade is made of metal, the surrounding resin easily melts and is easily exposed when heated and welded. The protrusion suppression effect can be enjoyed effectively.

According to a seventh aspect of the present invention, in the catheter according to any one of the first to sixth aspects, an inner diameter dimension of the blade tube and an inner diameter dimension of the end tube at a butt portion between the blade tube and the end tube Are equal.

According to the catheter structured according to this aspect, for example, when delivering or collecting another member such as a filter through the inner hole of the catheter, the other member is brought into contact with the end tube and the blade tube on the inner surface of the catheter. The possibility of being caught can be reduced.

The catheter according to the present invention is not limited in any way. For example, it is preferable that the catheter be a filter collection catheter that collects a filter that is disposed in a blood vessel and captures debris such as a thrombus or blood clot. . That is, according to an eighth aspect of the present invention, in the catheter according to any one of the first to seventh aspects, the filter is a catheter for collecting a filter disposed in a blood vessel.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a catheter including a blade tube provided with a reinforcing blade, wherein the end tube is disposed on at least one end side of the blade tube, and axial end surfaces are arranged. When the cover tube is extrapolated across both the blade tube and the end tube, the blade tube and the extrapolated portion of the end tube in the end tube are heated and welded. The amount of heat applied to the outer end portion in the axial direction of the end tube in the covered tube is made larger than the amount of heat applied to the butted portion of the blade tube and the end tube in the covered tube.

According to the method for manufacturing a catheter according to this aspect, the amount of heat applied to the butt portion between the blade tube and the end tube in the covered tube is relatively reduced, so that the resin is melted at the end of the blade tube and the reinforcing blade is ejected. In addition, the amount of heat applied to the outer end portion of the end tube in the axial direction of the end tube in the cover tube is made relatively large, so that the end tube can be more securely welded and the end tube can be removed. It can be effectively prevented.

According to a tenth aspect of the present invention, in the method for manufacturing a catheter according to the ninth aspect, when the extrapolated portion of the covered tube in the blade tube and the end tube is heated and welded, The amount of heat applied to the inner side portion of the blade tube in the axial direction relative to the end portion of the blade tube with the end tube is made larger than the amount of heat applied to the end portion of the cover tube between the blade tube and the end tube.

According to the method for manufacturing a catheter according to this aspect, the amount of heat applied by welding is larger on both sides in the axial direction across the butted portion than the butted portion between the blade tube and the end tube. It is possible to obtain a greater welding strength on both sides in the axial direction across the butted portion than the butted portion between the blade tube and the end tube.

According to an eleventh aspect of the present invention, in a catheter including a blade tube provided with a reinforcing blade, a cover tube is extrapolated to the blade tube, and the cover tube protrudes from an axial end of the blade tube. In addition, the protruding portion of the covered tube from the axial end of the blade tube overlaps the end surface of the blade tube as viewed in the axial direction.

According to the catheter having the structure according to this aspect, since the covered tube that is extrapolated to the blade tube overlaps the axial end surface of the blade tube in the axial direction, the braided wire extends from the axial end surface of the blade tube. Even when the protrusion protrudes, the tip of the protruding braided wire is covered with the covering tube in the axial direction, or enters the covering tube. In addition, since the covered tube covers the axial end face of the blade tube, the protruding braided wire is made to have the required thickness in the axial direction while avoiding a large increase in the diameter of the blade tube due to thickening in the radial direction. It can be secured and covered.

According to a twelfth aspect of the present invention, in the catheter according to the eleventh aspect, an inner peripheral surface of the protruding portion of the covered tube is located on an inner peripheral side with respect to the reinforcing blade disposed on the blade tube. It is what you are doing.

</ RTI> According to the catheter having a structure according to this aspect, the braided wire can be more reliably prevented from protruding. In this aspect, it is more preferable to adopt an aspect in which the inner peripheral surface of the protruding portion of the covered tube is positioned on the inner peripheral side with respect to all the reinforcing blades (braided wires) arranged on the blade tube.

A thirteenth aspect of the present invention is the catheter according to the eleventh or twelfth aspect, wherein an outer diameter dimension of the protruding tip portion of the covered tube is equal to or smaller than an outer diameter dimension of the blade tube.

According to the catheter having the structure according to this aspect, the outer diameter of the protruding tip of the covered tube is set to be equal to or smaller than the outer diameter of the blade tube, so that the catheter can be smoothly inserted into the blood vessel or the like. It becomes possible.

A fourteenth aspect of the present invention is the catheter according to any one of the eleventh to thirteenth aspects, wherein the protruding portion of the covered tube has a tapered shape in which an outer diameter dimension gradually decreases toward a protruding tip. It has a part.

According to the catheter having a structure according to this aspect, since the hooking or the like can be suppressed during the insertion operation into the blood vessel, the workability of the procedure can be improved.

According to a fifteenth aspect of the present invention, in the catheter according to any one of the eleventh to fourteenth aspects, the protruding portion of the covered tube has a thickness dimension larger than that of a portion extrapolated to the blade tube. It has been enlarged.

According to the catheter having the structure according to this aspect, the outer diameter of the catheter can be reduced and the insertion property can be improved by reducing the thickness of the portion of the covered tube that is extrapolated to the blade tube. In addition, since the thickness dimension of the portion protruding from the blade tube is increased, the protrusion of the reinforcing blade from the blade tube can be prevented more stably.

The catheter according to the present invention is not limited in any way, but is preferably a delivery catheter, for example. That is, according to a sixteenth aspect of the present invention, in the catheter according to any one of the eleventh to fifteenth aspects, a filter capable of capturing debris such as thrombus in blood is delivered to a predetermined position in the blood vessel. This is a delivery catheter.

In this aspect, the filter can be positioned with respect to the delivery catheter by bringing the protruding portion of the covered tube into contact with a stopper provided on the filter, as in the embodiment described later. In particular, for example, in combination with the thirteenth aspect and the fourteenth aspect, the outer diameter dimension at the protruding tip portion of the cover tube is made equal to or less than the outer diameter dimension of the blade tube, and the inner diameter dimension is also reduced toward the protruding tip portion. In addition, or in combination with the fifteenth aspect, for example, by increasing the thickness dimension of the protruding portion of the covered tube toward the inner peripheral side, it is also possible to reduce the diameter of the stopper provided in the filter, Thereby, it is also possible to improve the insertion property of the catheter when delivering the filter.

According to a seventeenth aspect of the present invention, in the catheter according to any one of the eleventh to sixteenth aspects, the protruding portion of the covering tube overlaps the axial end surface of the blade tube in a contact state. Is.

According to the catheter having the structure according to this aspect, the leading end of the braided wire protruding from the blade tube directly enters the covered tube, and the protruding braided wire can be prevented from being exposed in the covered tube. Further, it is possible to prevent blood or the like from entering and staying in the gap between the blade tube and the cover tube in the axial direction.

According to an eighteenth aspect of the present invention, in the catheter according to any one of the eleventh to seventeenth aspects, a contrast marker is provided on an outer peripheral surface of a distal end portion of the blade tube, and the contrast marker is covered with the cover. It is covered with a tube.

According to the catheter having the structure according to this aspect, the catheter can be inserted into the blood vessel while confirming the position of the distal end portion of the blade tube during the operation. In particular, the axial distance from the distal end portion of the blade tube to the distal end portion of the catheter can be increased by forming the axial end portion of the catheter with a covered tube without providing a soft resin tube at the axial end portion of the blade tube. It is also possible to keep it small, and it is also possible to keep the deviation between the position of the distal end portion of the blade tube that can be confirmed during the operation and the actual distal end position of the catheter small.

According to the catheter and the catheter manufacturing method according to any one of the first to tenth aspects of the present invention, the blade tube at the time of welding the cover tube while ensuring the joining strength of the end tube to the end of the blade tube This makes it possible to avoid damage to the machine.

Further, according to the catheter having the structure according to any one of the eleventh to eighteenth aspects of the present invention, the braided wire (reinforcing blade) protruding in the axial direction from the blade tube is arranged in the axial direction with respect to the blade tube. It is possible to cover in the axial direction by the covered tube overlapped with the eye.

The front view which shows the whole catheter as the 1st Embodiment of this invention. The front view which expands and shows the principal part of the catheter shown by FIG. III-III sectional view in FIG. IV-IV sectional drawing in FIG. FIG. 5 is a longitudinal sectional view showing the main part in the VV section of FIG. 4. Explanatory drawing for demonstrating the method to manufacture the catheter shown by FIG. It is a longitudinal cross-sectional view which shows the catheter as the 2nd Embodiment of this invention, Comprising: The figure corresponding to FIG. It is a longitudinal cross-sectional view which shows the catheter as the 3rd Embodiment of this invention, Comprising: The figure corresponding to FIG. The front view which shows the whole catheter for embolus removal comprised including the delivery catheter which is 4th Embodiment of the catheter in this invention. The front view which shows the whole delivery catheter which is 4th Embodiment of the catheter in this invention. The front view which expands and shows the principal part of FIG. FIG. 12 is an enlarged view of a section XII-XII in FIG. FIG. 12 is an enlarged view of the XIII-XIII cross section of FIG. Sectional drawing which shows the principal part in the XIV-XIV cross section of FIG. Explanatory drawing for demonstrating an example of the specific manufacturing method of a division tube (cover tube). The front view which shows the whole wire with a filter which comprises the catheter for embolus removal shown by FIG. It is a longitudinal cross-sectional view which shows the catheter of another aspect of this invention, Comprising: The figure corresponding to FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First, FIGS. 1 to 5 show a filter recovery catheter (hereinafter referred to as a recovery catheter) 10 which is a first embodiment of a catheter according to the present invention. The recovery catheter 10 is a catheter for recovering a filter that captures and removes debris such as blood clots and blood clots delivered to a treatment site in a blood vessel by a separate delivery catheter or the like from the blood vessel after treatment. is there. In the following description, the axial direction refers to the left-right direction in FIG. 1 in which the recovery catheter 10 extends, the distal end side refers to the left side in FIG. 1, and the proximal end side refers to the right side in FIG. To do.

More specifically, the recovery catheter 10 includes a distal-side distal shaft 12 and a proximal-side proxy shaft 14. The distal shaft 12 is composed of a single layer resin tube or the like, while the proxy shaft 14 is a hollow long member, and is composed of a metal such as stainless steel or a synthetic resin.

Further, the distal shaft 12 is fixed to the outer peripheral surface of the distal end portion of the proxy shaft 14, and the long proxy shaft 14 extends from the base end side of the distal shaft 12. The inner diameter of the distal shaft 12 is larger than the outer diameter of the proximal shaft 14, and a port in which the proximal end side of the distal shaft 12 opens to the outside in the middle portion of the recovery catheter 10 in the length direction. Part 16 is designated. Further, at the proximal end of the proximal shaft 14, a connector portion 18 that allows a user to hold and operate is provided.

On the other hand, an outer tube 20 made of a blade tube is extrapolated to the distal end portion of the distal shaft 12. In the present embodiment, the blade tube targeted by the present invention is the outer tube 20, and the catheter targeted by the present invention will be described later according to the present invention with respect to the outer tube 20, as will be described in detail below. The end tube 28 and the covering tube 30 are provided as a composite structure. Therefore, the present invention can be interpreted without including the distal shaft 12 and the proximal shaft 14 as targets.

That is, the outer tube 20 is configured such that a reinforcing blade 22 made of metal or the like is embedded and fixed in a cylindrical wall 24 made of a resin tube, and the outer tube 20 is substantially in the axial direction. It is constituted by a blade tube over the entire length. In the present embodiment, the reinforcing blade 22 is embedded in the middle portion of the cylindrical wall 24 in the thickness direction, and the inner peripheral side and the outer peripheral side of the reinforcing blade 22 are respectively covered with a resin tube material. Although the structures of the distal shaft 12 and the proxy shaft 14 are not limited in any way, these shafts 12 and 14 are blades in which a reinforcing blade is embedded and fixed inside the cylindrical wall, like the outer tube 20. By using a tube, the recovery catheter 10 can be constituted by a blade tube over substantially the entire length in the axial direction.

In the present embodiment, the radial width dimension To (see FIG. 4) of the outer tube 20 is preferably 0.04 mm ≦ To ≦ 1.0 mm, and the axial dimension L (see FIG. 3) is suitably. Is 50 mm ≦ L ≦ 70 mm. By setting the radial thickness dimension To and the axial dimension L in the above ranges, flexibility and good operability can be obtained. Further, an annular contrast marker 26 made of Pt or the like is attached to the outer peripheral surface of the distal end portion of the outer tube 20 by being extrapolated. Thereby, the insertion operation of the recovery catheter 10 can be performed while confirming the position of the distal end portion of the outer tube 20 with X-rays. However, in the present embodiment, the reinforcing blade 22 made of metal or the like extends to substantially the front end of the outer tube 20, and the position of the front end portion of the outer tube 20 can be confirmed also by the X-ray with the reinforcing blade 22. Therefore, the contrast marker 26 is not essential.

The outer tube 20 that is a blade tube has a three-layer structure. The innermost layer is formed of a synthetic resin such as PTFE (polytetrafluoroethylene), and a metal such as thin stainless steel is formed on the outer peripheral side of the inner layer. Further, a reinforcing blade 22 made of a mesh-like sleeve braided with a wire made of synthetic resin is disposed. Further, a synthetic resin outer layer made of polyamide or the like is formed on the outer peripheral side of the reinforcing blade 22, and the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer are bonded or welded, whereby the reinforcing blade The inner and outer layers are integrated by fixing in a state where 22 is embedded. That is, the cylindrical wall 24 in which the reinforcing blade 22 is embedded is configured including the inner layer made of PTFE or the like and the outer layer made of polyamide or the like. In the present embodiment, the outer layer of the cylindrical wall 24 in the outer tube 20, end tubes 28 (28 a, 28 b), which will be described later, and the covered tube 30 are each made of synthetic resin of substantially the same material, that is, under conditions close to each other. In particular, in the present embodiment, these tubes 20, 28, 30 are made of nylon. In addition, the material which comprises each tube 20, 28, 30 can employ | adopt suitably a polyamide elastomer, urethane, etc., for example. For example, stainless steel or tungsten can be suitably used as the material constituting the reinforcing blade 22.

In addition, an end tube 28 is disposed at at least one end of the outer tube 20 so that the outer tube 20 and the end surface are abutted with each other. In this embodiment, a gap is provided between the end tube 28 and the outer tube 20. Without being substantially provided, the end faces are arranged in series in a state where the end faces are substantially in contact with each other. In particular, in this embodiment, end tubes 28 a and 28 b are provided on both sides of the outer tube 20, and a distal end tube 28 a is provided on the distal end side of the outer tube 20, while the proximal end side of the outer tube 20 is provided. A proximal end tube 28b is provided on the base. The reinforcing blades 22 are not embedded in these end tubes 28 a and 28 b, and both end tubes 28 a and 28 b are made softer than the outer tube 20. Although the outer tube 20 is relatively hard because the reinforcing blade 22 is embedded, the resin portion in the outer tube 20, that is, the rigidity of the cylindrical wall 24 is not limited in any way. For example, it may be made softer than both end tubes 28a and 28b. In the present embodiment, the outer and inner diameters of the end tubes 28 a and 28 b are substantially the same as those of the outer tube 20. As described above, by making the outer diameter and inner diameter of the end tubes 28a and 28b and the outer tube 20 substantially equal to each other at the abutting portion between the end tubes 28a and 28b and the outer tube 20 on the outer peripheral surface and the inner peripheral surface. A step can be made difficult.

In the outer tube 20 as described above, the distal end portion of the distal shaft 12 is inserted from the proximal end side of the proximal end tube 28b provided on the proximal end side, and the proximal end of the proximal end tube 28b is inserted. The side inner peripheral surface is welded or bonded to the outer peripheral surface of the distal shaft 12, and the proximal end portion of the proximal end tube 28b is reduced in diameter. The proximal end portion of the proximal end tube 28b may not be reduced in diameter, and the outer diameter of the proximal end tube 28b may be substantially constant in the axial direction.

Further, a covering tube 30 is provided on the outer peripheral side of the outer tube 20 so as to cover the outer peripheral surface of the outer tube 20 over the entire length in the axial direction. The covered tube 30 is thinner than the outer tube 20, and the radial width dimension Tc (see FIG. 4) is preferably 0.01 mm ≦ Tc ≦ 0.10 mm. And the base end side of this covered tube 30 is extrapolated across the abutting part with the base end side end tube 28b provided in the base end side of the outer tube 20, and from the base end of the covered tube 30, The proximal end tube 28b protrudes axially outward (proximal end). The proximal end tube 28b may not protrude from the proximal end of the covered tube 30, and the proximal end of the proximal end tube 28b and the proximal end of the covered tube 30 are substantially in the same position in the axial direction. Also good.

On the other hand, the distal end side of the cover tube 30 protrudes to the distal end side from the outer tube 20 and covers the distal end side end tube 28a provided on the distal end side of the outer tube 20 over substantially the entire length. In this embodiment, The distal end side end surface of the cover tube 30 and the distal end side end surface of the distal end side end tube 28a are at substantially the same position in the axial direction. The covering tube 30 is fixed to the outer peripheral surfaces of the outer tube 20 and the both end tubes 28a and 28b over substantially the entire length of the covering tube 30. That is, in this embodiment, the distal end surface of the recovery catheter 10 is constituted by the distal end surface of the distal end tube 28a and the distal end surface of the covered tube 30, and is flat and spreads perpendicular to the axial direction. An annular surface. In this embodiment, the covered tube 30 is disposed so as to cover the outer periphery of the contrast marker 26.

In this embodiment, the covered tube 30 is divided into four in the length direction in a single product state before extrapolation to the outer tube 20, and is composed of divided tubes 32a, 32b, 32c, and 32d. In other words, the divided tubes 32a, 32b, 32c, 32d arranged in series in the length direction from the distal end side are extrapolated to the outer tube 20 and the both end tubes 28a, 28b, and are located on the most distal end side. The divided tube 32a protrudes from the outer tube 20 to the distal end side to cover the distal end side end tube 28a, and the divided tube 32d positioned closest to the proximal end protrudes from the outer tube 20 to the proximal end side to project the proximal end side end tube. 28b. In addition, the number of the division | segmentation tubes which comprise the covered tube 30 is not limited at all. That is, it may be two, three, five or more, and can be changed as appropriate. However, the covering tube does not need to be constituted by a divided tube, and may be constituted by a single tubular member.

And these division | segmentation tubes 32a, 32b, 32c, 32d, the outer tube 20, and both ends tube 28a, 28b are heat-processed, these are fuse-integrated and the covered tube 30 is comprised, The covering tube 30 is welded to the outer peripheral surfaces of the outer tube 20 and the both end tubes 28a and 28b. In other words, the split tube 32a at the distal end is welded to the outer peripheral surfaces of the tubes 20 and 28a across the outer tube 20 and the distal end tube 28a, and the split tube 32d at the proximal end is connected to the outer tube 20 and the proximal end. It is welded to both tubes 20 and 28b across the side end tube 28b. On the other hand, intermediate divided tubes 32 b and 32 c are welded to the outer peripheral surface of the outer tube 20.

A specific example of the method for manufacturing the recovery catheter 10 will be described below with reference to FIGS. 6A to 6C, but the method for manufacturing the recovery catheter 10 is not limited in any way. In FIGS. 6 (a) to 6 (c), the contrast marker (26) is not shown.

That is, as shown in FIG. 6 (a), the outer tube 20 and both end tubes 28a, 28b are extrapolated to a core rod 34 that extends substantially straight with their axial end faces butting each other. The tube 30 is extrapolated on the outer peripheral surfaces of the tubes 20, 28a, 28b. Thereafter, the core rod 34 with the tubes 20, 28 a, 28 b, 30 inserted therein is set in a substantially cylindrical welding mold 36. The welding die 36 and the core rod 34 are arranged on the same central axis, and an appropriate gap is set between the outer peripheral surface of the covering tube 30 and the inner peripheral surface of the welding die 36. Then, by heating the welding mold 36 to heat and melt the covering tube 30, the extrapolated portion of the covering tube 30 is welded to the outer tube 20 and both end tubes 28a and 28b. The end tube having the structure according to any one of the first to tenth aspects is the distal end side tube 28a, and in FIGS. 6 (a) to 6 (c), the outer tube 20 and the distal end side end tube 28a. Although the state of welding with the covering tube 30 is shown, the fixing mode of the proximal end side tube 28b and the covering tube 30 (divided tube 32d) is not limited at all, and the distal end side tube 28a Similarly, the structure according to any one of the first to tenth aspects may be adopted, or the structures may be fixed to each other by means other than welding, for example, adhesion. Such welding may be performed in a state where a thin shrink tube is further extrapolated with respect to the covered tube 30. In such a case, the temperature of the welding die 36 and the temperature applied to the covering tube 30 do not necessarily coincide with each other. However, since there is a correlation, the higher the (temperature of the welding die 36), The temperature applied to the tube 30 is also considered high.

Here, FIG. 6 (a) shows a welding mode between the covered tube 30 and a portion of the outer tube 20 that is closer to the base end side than the butted portion of the distal end side tube 28a. That is, in FIG. 6A, the welding die 36 is positioned on the base end side with respect to the abutting portion between the outer tube 20 and the distal end side end tube 28a, and welding is performed in such a state, thereby covering the tube 30. And the outer tube 20 are welded to each other. The welding conditions in such a state are not limited in any way, but in the present embodiment, the welding mold 36 is heated to an appropriately set temperature within the range of 165 to 235 degrees, and 5 It is preferable to heat-weld for a time set appropriately between ˜15 seconds. More preferably, heat treatment is performed for 8 to 12 seconds at a temperature within the range of 180 to 220 degrees.

After the welding, as shown in FIG. 6B, the welding mold 36 and the core bar 34 are moved relative to each other so that the welding mold 36 is positioned at the abutting portion between the outer tube 20 and the distal end side tube 28a. Let Welding is performed in such a state, and the covered tube 30, the outer tube 20, and the distal end side end tube 28a are welded to each other. The welding conditions in such a state are not limited in any way, but in the present embodiment, in FIG. 6B, the welding mold 36 is set to a temperature appropriately set within the range of 140 to 175 degrees. In the heated state, it is preferable to heat-weld for a time set appropriately between 5 to 30 seconds. More preferably, the heat treatment is performed for 8 to 12 seconds at a temperature in the range of 150 to 165 degrees and lower than that in FIGS.

Further, after the welding, as shown in FIG. 6C, the welding die 36 and the core bar 34 are relatively moved so that the welding die 36 is moved to the outer end portion in the axial direction of the distal end side end tube 28a. To be located. Welding is performed in such a state, and the covered tube 30 and the outer end portion in the axial direction of the distal end side end tube 28a are welded to each other. The welding conditions in such a state are not limited in any way, but in this embodiment, the welding mold 36 is heated to an appropriately set temperature within a range of 160 to 220 degrees, and 5 It is preferable to heat-weld for a time set appropriately between ˜15 seconds. More preferably, the heat treatment is performed at a temperature in the range of 165 to 200 degrees for 5 to 10 seconds.

Thereafter, separately prepared distal shaft 12, proxy shaft 14, and connector portion 18 are fixed to the outer tube 20 manufactured by the procedure shown in FIGS. 6 (a) to 6 (c). Manufacturing. In addition, these adhering means and the order of adhering are not limited at all.

Here, although depending on the material of each tube, in the present embodiment, the outer layer of the outer tube 20, the distal end side end tube 28 a, and the covered tube 30 are made of substantially the same material, and therefore, the amount of heat applied during welding. The (heat energy amount) can be expressed by (heating temperature) × (heating time). That is, in this embodiment, the amount of heat applied at the time of welding is (a portion on the inner side in the axial direction with respect to the abutting portion of the outer tube 20 with the distal end side end tube 28a) ≧ (an axial direction in the distal end side end tube 28a). Outer end portion)> (abutting portion between the outer tube 20 and the distal end side end tube 28a). Since the outer tube 20 has a metal reinforcing blade 22 embedded in the outer tube 20 as compared with the distal end side tube 28a, the outer tube 20 is preferably (the shaft of the outer tube 20 with respect to the distal side end tube 28a rather than the butted portion. Inward direction portion >> (outward end portion in the axial direction of the distal end side end tube 28a). Therefore, also in the degree of welding with the covered tube 30, (the portion on the inner side in the axial direction with respect to the abutting portion of the outer tube 20 with the tip side end tube 28a)> (the outer side in the axial direction of the tip side end tube 28a) End portion)> (abutting portion between the outer tube 20 and the distal end side tube 28a), and the covered tube 30 sandwiches the abutting portion rather than the abutting portion between the outer tube 20 and the distal end side end tube 28. However, the degree of welding is increased on both sides.

In the above-described specific example, in FIGS. 6A to 6C, the welding mold 36 is set at a position where it does not overlap in the axial direction, but in each of FIGS. 6A to 6C. The welding position may partially overlap in the axial direction. In this way, when the welding mold 36 is sequentially moved in the axial direction to weld each part, the moving position of the welding mold 36 is adjusted, and the welding process is performed at a partially overlapping position, In addition to or instead of the heating temperature of the welding mold 36, each tube is subjected to welding processing at continuous positions without overlapping or by performing welding processing at discontinuous positions separated by a predetermined distance. The amount of welding heat applied to 20, 28a, 28b, and 30 can be controlled for each part. When the heat treatment is performed a plurality of times at the same location, for example, by partially overlapping the position of the welding mold 36 in the axial direction, for example, the effective heating temperature and heating time for the portion, that is, the resin The amount of heat of the heat treatment can be evaluated based on the heating time above the melting temperature.

Further, even if the entire welding mold 36 is heated substantially uniformly, the temperature at both end portions in the axial direction tends to be lower than that at the middle portion due to the uneven heat radiation area. By utilizing such a temperature characteristic of the welding mold 36 or locally cooling the welding mold 36 with air or the like, for example, welding of a butt portion between the outer tube 20 and the tip side end tube 28a is performed. It is also possible to carry out at a lower temperature.

By the welding process as described above, the boundary of the overlapping surface of the covered tube 30 and the outer tube 20 or the distal end side tube 28a disappears, and an integrated resin structure can be obtained. However, it is sufficient that the required welding strength is realized, between the overlapping surfaces of these tubes, particularly between the overlapping surfaces of the covered tube 30 at the abutting portion of the outer tube 20 and the distal end tube 28a, The space between the butted surfaces of the outer tube 20 and the distal end side end tube 28a may remain so that a boundary can be confirmed.

In the present embodiment, since the outer layer of the outer tube 20, the distal end side tube 28a, and the covering tube 30 are substantially the same material, there is a correlation between the amount of heat applied during welding and the degree of welding. When the material used for the tube is different and a material that is easily welded or a material that is difficult to weld is used, there is a case where there is no correlation between the amount of heat applied during welding and the degree of welding. However, the degree of welding in the covered tube 30 will be described later by making the outer end portion in the axial direction of the distal end end tube 28a larger than the butted portion of the outer tube 20 and the distal end end tube 28a. The effect of the present invention is exhibited. In the manufactured catheter, the degree of welding of the covered tube can be interpreted as the degree of integration by melting. For example, by performing a tensile test similar to JIS T 3268: 2012 (stripping Can be objectively grasped as (necessary force)) ≈ (degree of welding).

Further, the recovery catheter 10 is used for recovering a filter that is delivered to a predetermined position in the blood vessel by a separate delivery catheter and captures debris such as blood clots and blood clots. That is, the filter disposed in the blood vessel and used for treatment is accommodated in the outer tube 20 and the recovery catheter 10 is removed in this state, whereby the filter is recovered. In the present embodiment, since the inner diameter dimension of the distal end side tube 28a and the inner diameter dimension of the outer tube 20 are substantially equal, the filter does not get caught on the inner surface of the recovery catheter 10 and the filter is attached to the outer tube 20. Can be housed inside. In addition, the structure of a filter, the method of accommodating a filter in the outer tube 20, etc. are not limited at all.

In the recovery catheter 10 of the present embodiment configured as described above, the degree of welding is varied by varying the amount of heat applied during welding in the axial direction of the covered tube 30. That is, the amount of heat applied to the outer end portion of the cover tube 30 in the axial direction of the tip end tube 28a is larger than the amount of heat applied to the butted portion of the cover tube 30 between the outer tube 20 and the tip end tube 28a. By doing so, compared to the degree of welding of the butted portion of the outer tube 20 and the tip end tube 28a in the covered tube 30, the degree of welding of the outer end portion in the axial direction of the tip end tube 28a in the covered tube 30 is increased. doing.

Accordingly, the amount of heat applied to the abutting portion between the outer tube 20 and the distal end side end tube 28a, that is, for example, the heating temperature can be kept low, and the melting of the resin at the end of the outer tube 20 and the accompanying reinforcement Jumping out of the blade 22 can be avoided. Further, since the cover tube 30 and the distal end tube 28a are firmly welded on the distal end side of the outer tube 20, the distal end tube 28a can be stably positioned on the distal end side of the outer tube 20. Thus, the reinforcing blade 22 can be more reliably prevented from protruding in the axial direction.

In particular, in this embodiment, compared to the degree of welding of the covered tube 30 at the abutting portion between the outer tube 20 and the distal end side tube 28a, the inner side in the axial direction is larger than the abutting portion between the outer tube 20 and the distal end end tube 28a. Since the degree of welding of the cover tube 30 in the side portion is larger, the degree of welding is larger on both sides of the butted portion than the butted portion of the outer tube 20 and the distal end side tube 28a. Has been. That is, since the outer tube 20 and the distal end side tube 28a are firmly fixed via the covered tube 30 without increasing the degree of welding between the butted end surfaces, the distal side end tube 28a from the outer tube 20 is fixed. Can be effectively prevented from falling off.

Moreover, in this embodiment, since the front end side end surface of the covering tube 30 and the front end side end surface of the front end side end tube 28a are in the same position in the axial direction, both the tubes 28a and 30 can be welded from the front end. The covering tube 30 and the distal end side end tube 28a can be effectively prevented from peeling off.

Furthermore, in the present embodiment, since the covered tube 30 is thin, even if it is extrapolated to the outer tube 20, the diameter of the recovery catheter 10 is avoided, and the insertion property of the recovery catheter 10 is improved. Deterioration can be prevented.

The material of the reinforcing blade 22 is preferably a metal or a synthetic resin, but is not limited in any way. However, since the material of the reinforcing blade 22 is metal, the temperature of the reinforcing blade 22 is higher when the cover tube 30 is heated and welded than when the material of the reinforcing blade 22 is synthetic resin. Since the surrounding resin (cylinder wall 24) is easy to melt, the effect of the present embodiment that suppresses the heating temperature at the time of welding and prevents the resin from melting can be enjoyed effectively.

Next, FIG. 7 shows a filter recovery catheter (hereinafter referred to as a recovery catheter) 40 which is a second embodiment of the catheter according to the present invention. In the recovery catheter 40 of the present embodiment, the covered tube 30 protrudes axially outward from the end tube 28. In short, the distal end side end surface of the covered tube 30 is more than the distal end side end surface of the distal end end tube 28a. Located on the tip side. In the following description, members and parts that are substantially the same as those in the above-described embodiment are denoted by the same reference numerals as those in the above-described embodiment, and detailed description thereof is omitted.

Also in the present embodiment, when the covered tube 30 is welded, the degree of welding of the outer end portion in the axial direction of the distal end side end tube 28a is compared with the abutting portion between the outer tube 20 and the distal end side end tube 28a. By increasing the amount of heat applied, etc., the same effect as in the first embodiment can be exhibited.

In particular, in this embodiment, since the distal end portion of the recovery catheter 40 is formed only by the covered tube 30, the distal end portion of the recovery catheter 40 can be configured flexibly. And since it is made into the double layer structure of the covering tube 30 and the front end side end tube 28a in the base end side rather than the front-end | tip part of the catheter 40 for collection | recovery, while it can be comprised more rigidly, on the base end side further Since the cover tube 30 and the outer tube 20 have a double-layer structure, the cover tube 30 and the outer tube 20 can be made harder. In this way, by allowing the covered tube 30 to protrude from the distal end side end tube 28a to the distal end side, the flexibility of the recovery catheter 40 can be varied in the axial direction, for example, from the distal end side toward the proximal end side. It can also be configured to become gradually harder.

Next, FIG. 8 shows a filter collection catheter (hereinafter, collection catheter) 50 which is a third embodiment of the catheter according to the present invention. In the recovery catheter 50 of this embodiment, the end tube 28 protrudes axially outward from the covered tube 30. In short, the distal end surface of the distal end tube 28a is more than the distal end surface of the covered tube 30. Located on the tip side.

Also in the present embodiment, when the covered tube 30 is welded, the degree of welding of the outer end portion in the axial direction of the distal end side end tube 28a is compared with the abutting portion between the outer tube 20 and the distal end side end tube 28a. By increasing the amount of heat applied, etc., the same effect as in the first embodiment can be exhibited.

In particular, in the present embodiment, since the distal end side end tube 28a protrudes to the distal end side rather than the covered tube 30, the flexibility of the recovery catheter 50 is different in the axial direction as in the second embodiment. For example, it can be configured so as to gradually become harder from the distal end side toward the proximal end side. Further, since the distal end side end tube 28a has a smaller diameter than the covered tube 30, the distal end of the recovery catheter 50 can be made smaller in diameter, and the insertion property of the recovery catheter 50 can be improved.

FIG. 9 shows an embolus removal catheter 62 including a delivery catheter 60 which is a fourth embodiment of the catheter according to the present invention. 10 to 14 show a single delivery catheter 60. FIG. The delivery catheter 60 is a catheter for delivering a filter that captures and removes debris such as thrombus and blood clot in blood to a predetermined position such as a treatment site in the blood vessel. In the following description, the axial direction means the left-right direction in FIG. 9 where the delivery catheter 60 extends, the distal end side means the left side in FIG. 9, and the proximal end side means the right side in FIG. .

More specifically, the delivery catheter 60 is configured to include a distal shaft 64 on the distal end side and a proxy shaft 66 on the proximal end side. The distal shaft 64 is composed of a single layer resin tube or the like, while the proxy shaft 66 is a hollow long member, and is composed of a metal such as stainless steel or a synthetic resin.

Further, the distal shaft 64 is fixed to the outer peripheral surface of the distal end portion of the proxy shaft 66, and the long proxy shaft 66 extends from the proximal end side of the distal shaft 64. The inner diameter dimension of the distal shaft 64 is larger than the outer diameter dimension of the proxy shaft 66, and a port portion in which the proximal end side of the distal shaft 64 opens to the outside in the middle portion of the delivery catheter 60 in the longitudinal direction. 68. Further, a connector portion 70 that allows a user to hold and operate is provided at the proximal end of the proxy shaft 66.

On the other hand, an outer tube 72 made of a blade tube is extrapolated at the distal end portion of the distal shaft 64. In this embodiment, the blade tube targeted by the present invention is the outer tube 72, and the catheter targeted by the present invention covers the outer tube 72 according to the present invention, as will be described in detail below. It is a composite structure with a tube. Therefore, the present invention can be interpreted without including the distal shaft 64 and the proximal shaft 66.

That is, the outer tube 72 is configured by embedding and fixing a reinforcing blade 74 made of metal or the like in a cylindrical wall 76 made of a resin tube, and the outer tube 72 extends over substantially the entire length in the axial direction. It is comprised by. In this embodiment, the reinforcing blade 74 is embedded in the middle portion of the cylindrical wall 76 in the thickness direction, and the inner peripheral side and the outer peripheral side of the reinforcing blade 74 are respectively covered with a resin tube material. The structures of the distal shaft 64 and the proxy shaft 66 are not limited in any way, but the shafts 64 and 66 are blades in which a reinforcing blade is embedded and fixed inside the cylindrical wall, like the outer tube 72. By using a tube, the delivery catheter 60 can be configured by a blade tube over substantially the entire length in the axial direction.

In the present embodiment, the radial width dimension T (see FIG. 13) of the outer tube 72 is preferably 0.04 mm ≦ T ≦ 1.0 mm, and the axial dimension L (see FIG. 11) is suitably. Is 50 mm ≦ L ≦ 70 mm. By setting the radial thickness dimension T and the axial dimension L within the above ranges, flexibility and good operability can be obtained. Further, an annular contrast marker 78 made of Pt or the like is attached to the outer peripheral surface of the distal end portion of the outer tube 72 by being extrapolated. Thereby, the insertion operation of the delivery catheter 60 can be performed while confirming the position of the distal end portion of the outer tube 72 with X-rays. However, in the present embodiment, the reinforcing blade 74 made of metal or the like extends to the substantially distal end of the outer tube 72, and the position of the distal end portion of the outer tube 72 can be confirmed by X-rays even with the reinforcing blade 74. The contrast marker 78 is not essential.

The outer tube 72, which is a blade tube, has a three-layer structure. The innermost layer is formed of a synthetic resin such as PTFE (polytetrafluoroethylene), and a metal such as thin stainless steel is formed on the outer peripheral side of the inner layer. Further, a reinforcing blade 74 made of a mesh-like sleeve braided with a wire made of synthetic resin is disposed. Further, an outer layer of a synthetic resin made of polyamide or the like is formed on the outer peripheral side of the reinforcing blade 74, and the outer peripheral surface of the inner layer and the inner peripheral surface of the outer layer are bonded or welded, whereby the reinforcing blade In a state where 74 is embedded, the inner and outer layers are integrated by fixing. That is, the cylindrical wall 76 in which the reinforcing blade 74 is embedded is configured including the inner layer made of PTFE or the like and the outer layer made of polyamide or the like.

Further, an end tube 80 is arranged in series at the base end of the outer tube 72 so that the outer tube 72 and the end face are abutted. In the present embodiment, no reinforcing blade 74 is embedded in the end tube 80, and the end tube 80 is softer than the outer tube 72. In particular, in this embodiment, the outer diameter and the inner diameter of the end tube 80 are substantially equal to those of the outer tube 72.

In the outer tube 72 as described above, the distal end portion of the distal shaft 64 is inserted from the base end side of the end tube 80 provided on the base end side, and the base end side inner peripheral surface of the end tube 80 is the disc end side. In the present embodiment, the base end portion of the end tube 80 is reduced in diameter by being welded or bonded to the outer peripheral surface of the tar shaft 64. The proximal end portion of the end tube 80 may not be reduced in diameter, and the outer diameter of the end tube 80 may be substantially constant in the axial direction.

Furthermore, a cover tube 82 is provided on the outer peripheral side of the outer tube 72 so as to cover the outer peripheral surface of the outer tube 72 over the entire length in the axial direction. The base end side of the cover tube 82 is extrapolated across the abutting portion with the end tube 80 at the base end of the outer tube 72, and the end tube 80 is axially outward from the base end of the cover tube 82 ( Projects to the base end side. Note that the end tube 80 may not protrude from the base end of the cover tube 82, and the base end of the end tube 80 and the base end of the cover tube 82 may be substantially in the same position in the axial direction. On the other hand, the distal end side of the cover tube 82 protrudes axially outward (front end side) from the distal end portion of the outer tube 72. The covered tube 82 is fixed to the outer peripheral surfaces of the outer tube 72 and the end tube 80 by adhesion, welding, or the like. In the present embodiment, the covered tube 82 is disposed so as to cover the outer periphery of the contrast marker 78.

Here, in the covered tube 82, the outer diameter dimension of the portion protruding from the outer tube 72 toward the distal end side (a distal end cover portion 86 to be described later) is gradually reduced toward the protruding distal end, while the outer tube 72 extends from the distal end side. The inner diameter dimension of the portion (tip cover portion 86) that protrudes in the direction is substantially equal to the inner diameter dimension of the outer tube 72, and is substantially constant in the axial direction including the protruding tip section. As a result, the portion of the covered tube 82 that protrudes from the outer tube 72 to the distal end side is positioned on the outer side (front end side) of the outer tube 72 in the axial direction, and the covered tube 82 is positioned at the distal end of the outer tube 72 in the axial direction. It overlaps over substantially the entire side end face. In the present embodiment, the inner peripheral surface 84 of the portion of the cover tube 82 that protrudes from the outer tube 72 to the distal end side (the distal end cover portion 86) is more than all the reinforcing blades 74 that are arranged embedded in the outer tube 72. Located on the inner circumference.

That is, the cover tube 82 is configured to include a tip cover portion 86 that protrudes from the outer tube 72 toward the tip side. Therefore, in the present embodiment, the protruding portion from the axial end (tip) of the outer tube 72 (blade tube) in the covered tube 82 is constituted by the tip cover portion 86. The tip cover portion 86 has a predetermined radial width W ₁ (see FIG. 14), extends from the outer tube 72 to the tip side, and covers the outer peripheral surface of the outer tube 72 in the covered tube 82. the radial width W ₂ (see FIG. 14) are small (W ₂ <W ₁₎ from the tip cover 86.

In the present embodiment, the outer peripheral surface of the tip cover portion 86 has an inclined surface whose outer diameter is gradually reduced toward the projecting tip. That is, the tip cover portion 86 is a tapered portion 88 at the projecting tip. have. Particularly in this embodiment, the outer peripheral surface of the tapered portion 88 is a curved inclined surface 90 that is inclined while being curved. Thereby, in this embodiment, the outer diameter dimension in the protrusion front-end | tip part of the covering tube 82 (front-end | tip cover part 86) is made smaller than the outer diameter dimension of the outer tube 72. FIG. In the present embodiment, the base end side end surface of the front end cover portion 86 and the front end side end surface of the outer tube 72 are overlapped with each other with almost no gap.

In this embodiment, the cover tube 82 is divided into four in the length direction in a single product state before extrapolation to the outer tube 72, and is composed of divided tubes 92a, 92b, 92c, and 92d. In other words, the divided tubes 92a, 92b, 92c, and 92d arranged in series in the length direction from the distal end side are extrapolated to the outer tube 72 and the end tube 80, and the divided tube located at the most distal end side. 92a has a distal end cover portion 86 and protrudes from the outer tube 72 to the distal end side, and a split tube 92d positioned closest to the proximal end projects from the outer tube 72 to the proximal end side and straddles the end tube 80. doing. In addition, the number of the division | segmentation tubes which comprise the covered tube 82 is not limited at all. That is, it may be two, three, five or more, and can be changed as appropriate. However, the covering tube does not need to be constituted by a divided tube, and may be constituted by a single tubular member.

The divided tubes 92a, 92b, 92c, and 92d, the outer tube 72, and the end tube 80 are subjected to heat treatment so that they are melted and integrated to form the covered tube 82, and the covered tube 82 is also covered. A tube 82 is welded to the outer peripheral surfaces of the outer tube 72 and the end tube 80. That is, the split tube 92a at the distal end is welded to the outer peripheral surface of the outer tube 72 and protrudes toward the distal end side, and the split tube 92d at the proximal end straddles the outer tube 72 and the end tube 80, and both tubes 72, 80 It is welded to. On the other hand, intermediate divided tubes 92 b and 92 c are welded to the outer peripheral surface of the outer tube 72.

A specific example of the method of manufacturing the divided tube 92a will be described below with reference to FIG. 15, but the method of manufacturing the divided tube 92a and the covered tube 82 is not limited in any way.

That is, for example, after inserting a stepped pin 94 whose base end side has a larger diameter into a resin tube 92a ′ having a substantially constant thickness dimension, the base end side (stepped side of the resin tube 92a ′ is provided. A portion that is extrapolated to the large diameter portion of the pin 94 is stretched by the stretching plate 96. As a result, a sufficient axial dimension is ensured in a state where the proximal end side of the resin tube 92a 'is thinner than the distal end side. From this state, after the extension plate 96 and the stepped pin 94 are removed, the distal end side before the outer tube 72 is extrapolated by cutting at a predetermined position on the distal end side of the resin tube 92a ′ has a smaller diameter than the proximal end side. A divided tube 92a is formed.

Then, the divided tubes 92d, 92c, and 92b are sequentially extrapolated from the distal end side with respect to the outer tube 72 and the end tube 80, and finally the divided tube 92a formed as described above has a small diameter. Is inserted in a state protruding from the outer tube 72 outward in the axial direction. Further, the split tube 92a (cover tube 82) is shown in FIG. 14 by inserting a core rod (not shown) extending substantially straight into the outer tube 72 and the split tube 92a in such a state and performing a heat welding process. It is fixed in a state where That is, in this embodiment, the split tube 92a is extrapolated to the distal end portion of the outer tube 72 and subjected to a welding process, whereby the proximal end side end surface of the distal end cover portion 86 and the distal end side end surface of the outer tube 72 are separated. The substantially entire surface is in contact with no gap and can be fixed as required.

However, the manufacturing method of the divided tube 92a is not limited to the above-described embodiment. That is, for example, a resin tube is formed into a predetermined shape (that is, a shape in which the outer diameter is a smaller diameter toward the distal end side, and the shape shown in FIG. 14 in the present embodiment), and is then extrapolated to the outer tube 72. In such a case, the proximal end surface of the distal end cover portion 86 and the distal end surface of the outer tube 72 may be in contact with each other in a non-fixed state or a fixed state. Alternatively, a resin tube having a substantially constant diameter may be extrapolated to the outer tube 72 and then heated to reduce the diameter so as to have the shape of FIG.

And the wire 98 with a filter shown in FIG. 16 is attached to the delivery catheter 60 having the shape as described above. The filter-attached wire 98 has a longitudinal shape as a whole, and includes a long wire portion 100. Further, a filter portion 102 is provided at the tip portion of the wire portion 100, and the wire portion 100 is divided by the filter portion 102. In other words, the wire portion 100 extends from the distal end and the proximal end of the filter portion 102. On the other hand, the proximal end portion of the wire portion 100 is a proximal end portion 104 for a user to hold and operate.

The wire portion 100 has an axial dimension longer than that of the delivery catheter 60 and is made of, for example, a synthetic resin having a certain degree of flexibility or stainless steel. In this embodiment, the stainless steel extends continuously in the axial direction and has a certain degree of flexibility. The diameter of the wire portion 100 is smaller than the inner diameter of the distal shaft 64 so that the wire portion 100 can be inserted into the inner hole of the distal shaft 64.

Further, in the wire portion 100, annular contrast rings 106 a and 106 b are extrapolated at both ends of the filter portion 102, and the proximal end side is inserted into the inner hole of the distal shaft 64 from the distal contrast ring 106 a. Thus, the inside of the distal shaft 64 can be slid. The filter portion 102 has a cylindrical shape having a spiral structure as a whole, and is formed of a Ni—Ti alloy in this embodiment. Further, a synthetic resin formed from a nonwoven fabric or a woven or knitted fabric of a biocompatible material such as polyurethane is provided on the distal end side of the spiral portion of the filter portion 102 so that blood or the like can pass through the filter portion 102. On the other hand, debris such as blood clots and blood clots cannot pass through the filter unit 102. The outer diameter dimensions of the contrast rings 106 a and 106 b are smaller than the inner diameter dimension of the tip cover portion 86 in the covered tube 82.

Furthermore, a stopper 108 is fitted and fixed to the wire portion 100 on the distal end side with respect to the contrast ring 106a on the distal end side. The stopper 108 has a tapered cylindrical shape with an outer diameter dimension that decreases toward the distal end side. The distal end side is substantially equal to the outer diameter dimension of the wire portion 100, while the proximal end side is covered tube 82. It is made larger than the internal diameter dimension of the front-end | tip cover part 86 in FIG.

The embolus removal catheter 62 of this embodiment is configured by inserting the filter-equipped wire 98 having the above-described shape into the delivery catheter 60. Specifically, the proximal end of the wire with filter 98 is inserted from the opening on the distal end side of the distal end cover portion 86 in the covered tube 82 of the delivery catheter 60, and the proximal end of the wire with filter 98 is connected to the distal shaft 64. It is made to protrude from the port part 68 which is a base end side opening part of the base end side. On the other hand, the filter portion 102, the contrast rings 106 a and 106 b, and the stopper 108 provided at the distal end portion of the wire 98 with filter are located on the distal end side of the distal end cover portion 86 in the covered tube 82.

When using the embolus removal catheter 62 structured as described above, first, from the state of FIG. 9, for example, while fixing the delivery catheter 60, the proximal end portion 104 is grasped and the filter-attached wire 98 is secured to the proximal end. Pull to the side. Accordingly, the wire portion 100 inserted through the inner shaft of the distal shaft 64 and the outer tube 72 is pulled to the proximal end side, and the filter portion 102 and the contrast rings 106a and 106b protruding from the distal end of the delivery catheter 60 are removed from the outer tube. 72. At this time, since the filter portion 102 is formed of a Ni—Ti alloy having elasticity, the filter portion 102 is accommodated in the outer tube 72 while being elastically deformed. The pulling of the wire 98 with a filter is restricted by the base end of the stopper 108 coming into contact with the distal end cover portion 86 of the covered tube 82. In this embodiment, since the distal end cover portion 86 has a thickness dimension increased toward the inner peripheral side, it is possible to reduce the diameter of the stopper 108, and when inserting the embolus removal catheter 62 into the blood vessel described later, It is also possible to improve the insertion property by reducing the insertion resistance.

Then, the embolus removal catheter 62 with the filter portion 102 housed in the outer tube 72 is inserted into a predetermined position through a guiding catheter previously placed in the blood vessel. Thereafter, in the catheter 62 for embolus removal that has reached the predetermined position, the wire 98 with filter is indwelled at a predetermined position in the blood vessel by pulling out the delivery catheter 60 from the proximal end while fixing the wire 98 with filter. . At that time, the filter portion 102 is exposed from the outer tube 72, and is thus placed in the blood vessel in an expanded state as shown in FIGS. 9 and 16 due to the elastic restoring action of the filter portion 102. . Thereby, debris such as thrombus and blood clot in the blood vessel is efficiently captured by the filter unit 102.

After such treatment, the treatment is completed by collecting the wire 98 with a filter placed in the blood vessel using a conventionally known collection catheter.

In the delivery catheter 60 of the present embodiment configured as described above, the covered tube 82 includes a distal end cover portion 86 that covers the distal end side of the outer tube 72. In particular, in the present embodiment, the distal end cover portion is configured. Since the inner diameter of 86 is substantially equal to the inner diameter of the outer tube 72, the reinforcing blade 74 can be more reliably prevented from protruding from the outer tube 72 in the axial direction. In addition, a curved inclined surface 90 is provided on the outer peripheral surface of the distal end cover portion 86, and the outer diameter of the cover tube 82 is gradually reduced toward the distal end side. Therefore, the delivery catheter 60 is inserted into the blood vessel. At this time, it is prevented from being caught on the blood vessel wall, and the insertion property can be improved.

In the present embodiment, the radial width W ₁ of the tip cover portion 86 in the covered tube 82 is the radial width of the portion other than the tip cover portion 86 in the covered tube 82, that is, the portion covering the outer peripheral surface of the outer tube 72. Since the diameter is larger than the dimension W ₂ (W ₂ <W ₁ ), the diameter of the delivery catheter 60 can be reduced, and the reinforcing blade 74 can be more effectively prevented from protruding in the axial direction.

Furthermore, in this embodiment, since the contrast marker 78 is provided at the distal end portion of the outer tube 72, the delivery operation of the delivery catheter 60 can be performed while confirming the distal end position of the outer tube 72. In particular, in this embodiment, since the contrast marker 78 is covered with the covering tube 82, the outer diameter of the delivery catheter 60 does not change abruptly, and it is prevented from being caught on the blood vessel wall or the like. The improvement of the property is achieved.

In addition, since the contrast marker 78 is provided in the front-end | tip part of the outer tube 72, it can confirm by X-ray during an operation | movement by reducing the axial direction dimension of the front-end | tip cover part 86 which protrudes from the outer tube 72 to a front-end | tip. The displacement between the position of the distal end portion of the outer tube 72 and the actual position of the distal end portion of the delivery catheter 60 can be suppressed to be small, and the insertion work into the blood vessel while grasping the distal end position of the delivery catheter 60 more accurately. Can also be performed.

As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not construed as being limited to the above specific description.

For example, in the fourth embodiment, the distal end cover portion of the cover tube has a smaller diameter than the portion covering the outer peripheral surface of the blade tube (outer tube 72) on the proximal end side. As long as it overlaps with the front end side end surface, the shape is not limited to the shape described in the fourth embodiment. Specifically, in the catheter 110 shown in FIG. 17, the inner diameter dimension of the distal end cover portion 114 of the covered tube 112 gradually decreases toward the distal end side in the axial direction. In particular, in this aspect, the inner and outer peripheral surfaces of the tip cover portion 114 have a tapered surface that is inclined at a substantially constant inclination angle, and the outer diameter dimension and the inner diameter dimension gradually decrease toward the protruding tip. 116. In addition, a small-diameter straight portion 118 that protrudes substantially parallel to the axial direction toward the distal end side is provided at the distal end of the tapered portion 116. The axial dimension of the straight portion 118 is not limited in any way, but if the axial dimension of the straight portion 118 (the distal end cover portion 114) is too long, the distal portion of the outer tube 72 and the distal end position of the catheter 110 are not aligned. There is a possibility that the deviation becomes large and it is difficult to grasp the distal end position of the catheter 110 when the catheter 110 is inserted. Further, in the fourth embodiment, the proximal end surface of the distal end cover portion 86 and the distal end end surface of the outer tube 72 are in contact with each other. However, as in this specific example, the proximal end of the distal end cover portion 114 is contacted. The side end surface and the end side end surface of the outer tube 72 may be spaced apart from each other.

In addition, in the said 4th Embodiment and this aspect, although the outer diameter dimension of the front-end | tip cover parts 86 and 114 was made small gradually toward the protrusion front end side, you may make it small in steps. However, the outer diameter dimension of the tip cover portion does not need to be reduced toward the protruding tip side, and may be substantially constant in the axial direction. In addition, it is preferable that the tip cover portion of the covering tube overlaps all the reinforcing blades when viewed in the axial direction of the blade tube, but at least one of the end faces of the reinforcing blades when viewed in the axial direction. A part of the reinforcing tube on the axial end face of the blade tube, for example, some of the reinforcing blades are not covered with the tip cover part, or the end face of the reinforcing blade is partially covered with the tip cover part. Such an embodiment may be employed.

Also, the inner diameter dimension of the tip cover portion is preferably substantially equal to or smaller than the inner diameter dimension of the blade tube (outer tube 72). Thereby, the axial protrusion of the reinforcing blade can be effectively prevented. However, the inner diameter dimension of the tip cover portion may be larger than the inner diameter dimension of the blade tube. That is, in the fourth embodiment, the tip cover portion 86 is overlapped over substantially the entire front end side end surface of the outer tube 72 as viewed in the axial direction. Is preferred. However, in the present invention, the tip cover portion is not essential.

Further, in the first embodiment, the distal end side end tube 28a and the proximal end side end tube 28b are provided on both sides of the outer tube 20, and the distal end side end tube 28a is one of the first to tenth embodiments. However, instead of the distal end side end tube, the base end side end tube may have a structure according to any of the first to tenth aspects. The structure according to any of the tenth aspects may be adopted. However, the end tubes do not need to be provided on both sides of the blade tube (outer tube 20), and may be provided only on one side. Even when the end tubes are provided on both sides of the blade tube (outer tube 20), it is preferable that at least one of the end tubes has a structure according to any one of the first to tenth aspects as described above. is there. However, in the present invention, the end tube is not essential.

Further, in the first to third embodiments, the relative movement of the welding die 36 and the core rod 34 and the welding of the covering tube 30 do not have to be performed in the order of (a) to (c) of FIG. For example, it may be performed in the opposite direction or may be performed in any order.

Furthermore, in the said embodiment, although the outer tube 20, the front end side end tube 28a, and the covering tube 30 were all cylindrical shapes extending substantially straight in the axial direction, these shapes are not limited at all. That is, the shape of the catheter according to the present invention is not limited at all. Therefore, the structure according to the present invention can be applied to the recovery catheter described in Japanese Patent Application Laid-Open No. 2008-35923 and Japanese Patent Application Laid-Open No. 2009-178518. Furthermore, in the fourth embodiment, in the embolus removal catheter 62, the wire portion 100 of the wire with filter 98 is inserted from the distal end side opening portion of the outer tube 72 and the proximal end side opening portion ( Although it protrudes from the port portion 68) to the base end side, it may protrude from the base end side opening of the connector portion 70 to the base end side through the distal shaft 64 and the proxy shaft 66. The catheter according to the present invention is not limited to the filter recovery catheter illustrated in the first to third embodiments or the embolus removal filter delivery catheter illustrated in the fourth embodiment. Alternatively, various catheters such as a delivery catheter for delivering a stent, a suction catheter, a balloon catheter, a guiding catheter, an atherectomy angioplasty catheter, and a catheter having a plurality of lumens may be employed.

Furthermore, in the first to third embodiments, the butted end surfaces of the outer tube 20 and the distal end side end tube 28a are in contact with each other. However, before the covering tube is welded, the blade tube (outer tube 20) and There may be a slight gap between the end tube. That is, the resin melted by welding the cover tube may enter between the blade tube and the end tube, and the blade tube and the end tube may not be welded directly.

Note that the welding of the covered tube is not limited to heat welding, and may be ultrasonic welding. Even when ultrasonic welding is used, the welding conditions are set appropriately, and the degree of welding with respect to the outer end portion of the end tube in the axial direction of the cover tube matches the blade tube and end tube of the cover tube. What is necessary is just to be made larger than the welding degree with respect to a part. In addition, even in the case of heat welding, it is possible to heat the welding mold by continuously moving the welding mold in the axial direction with respect to each tube without fixing the position of the welding mold. The amount of heat applied to each part of each tube may be adjusted by increasing / decreasing the moving speed in the axial direction. Furthermore, the heating means in the case of heat welding is not limited to the welding mold. However, the covering tube is not limited to an aspect in which the covering tube is welded to the outer peripheral surface of the blade tube or the end tube, and may be bonded, for example.

In the first to third embodiments, the degree of welding is varied by varying the amount of heat applied during welding, but the present invention is not limited to this mode. That is, even if the amount of heat applied is the same, it is possible to vary the degree of welding by changing the material constituting the tube, such as using a material that is easily welded or a material that is difficult to weld. Furthermore, even when the amount of heat applied at the time of welding is varied, not only the heating temperature as in the first embodiment but also the heating time may be varied, or both may be varied. Further, the degree of welding may be controlled by appropriately cooling the welding mold and / or the tube with air or the like according to the welding position in the axial direction. Furthermore, the degree of welding can be adjusted by appropriately selecting the material of the reinforcing blade. Prior to welding, by performing appropriate pretreatment such as wiping the surface of the welding site in the blade tube, the end tube, and the cover tube with ethanol or performing a blast treatment on the surface, for example, each tube It is also possible to adjust the degree of welding by modifying the surface.

Furthermore, in the first to third embodiments, the covering tube 30 is configured by the divided tubes 32a, 32b, 32c, and 32d having substantially the same structure, and in the fourth embodiment, the covering tube 30 is substantially the same. The covered tube 82 is configured by the divided tubes 92a, 92b, 92c, and 92d having the same structure. However, at least one of the divided tubes has a characteristic that is relatively different from that of the other divided tubes. May be. Here, the characteristics indicate chemical, material, or mechanical characteristics such as material, strength, and rigidity. Therefore, for example, if a split tube is adopted in which the rigidity of the split tube at both ends is small and the rigidity gradually increases inward in the axial direction, a catheter according to the rigidity of the split tube can be efficiently manufactured. Can be done. Further, for example, if a split tube whose rigidity is gradually increased as it goes in the proximal direction with the distal split tube having a small rigidity, a catheter according to the rigidity of the split tube can be efficiently manufactured. .

Furthermore, in the above-described embodiment, the covering tubes 30 and 82 are provided on the outer peripheral side of the contrast marker 26, but the contrast marker may be externally fixed on the outer peripheral side of the covering tube. However, in the present invention, the contrast marker is not essential.

Further, the reinforcing blade employed in the blade tube is not limited to a mesh shape, and may be, for example, a spiral shape that extends continuously in the axial direction. Further, the material of the braided wire constituting the reinforcing blade is not limited to metal, and may be formed of, for example, a synthetic resin. In this specification, the wire constituting the reinforcing blade is described as a braided wire for easy understanding, but is not limited to the braided structure.

10 (Filter) Recovery catheter (catheter)
12 Distal shaft 14 Proxy shaft 16 Port 18 Connector 20 Outer tube (blade tube)
22 Reinforcing blade 24 Cylinder wall 26 Contrast marker 28 End tube 28a End side end tube 28b Base end side end tube 30 Cover tube 32a, 32b, 32c, 32d Split tube 34 Core rod 36 Welding mold 40, 50 (filter) recovery Catheter (catheter)
60 Delivery catheter (catheter)
62 Embolization removal catheter 64 Distal shaft 66 Proxy shaft 68 Port portion 70 Connector portion 72 Outer tube (blade tube)
74 Reinforcing blade 76 Cylinder wall 78 Contrast marker 80 End tube 82 Covered tube 84 Inner peripheral surface 86 Tip cover (protruding portion of the cover tube)
88 Tapered portion 90 Curved inclined surface 92a, 92b, 92c, 92d Dividing tube 92a 'Resin tube 94 Stepped pin 96 Stretch plate 98 Wire with filter 100 Wire portion 102 Filter portion 104 Base end portion 106a, 106b Contrast ring 108 Stopper 110 Catheter 112 Cover tube 114 Tip cover (protruding portion of the cover tube)
116 Tapered part 118 Straight part

Claims (18)

A catheter having a blade tube with a reinforcing blade disposed thereon,
An end tube is arranged with its end face in the axial direction being abutted at at least one end of the blade tube, and a cover tube is extrapolated across both the blade tube and the end tube. While being welded to the outer peripheral surface of
A catheter in which the degree of welding of the end tube to the outer end portion of the end tube in the axial direction is larger than the degree of welding of the cover tube to the butted portion of the blade tube and the end tube. The catheter according to claim 1, wherein the outer ends in the axial direction of the end tube and the covered tube are at equal positions in the axial direction. The catheter according to claim 1, wherein the covered tube protrudes outward in the axial direction from the end tube. The catheter according to claim 1, wherein the end tube protrudes outward in the axial direction from the covered tube. The catheter according to any one of claims 1 to 4, wherein the covered tube is thinner than the blade tube. The catheter according to any one of claims 1 to 5, wherein the reinforcing blade is made of metal. The catheter according to any one of claims 1 to 6, wherein an inner diameter dimension of the blade tube and an inner diameter dimension of the end tube are equal to each other at a butt portion between the blade tube and the end tube. The catheter according to any one of claims 1 to 7, wherein the catheter is a filter collection catheter for collecting a filter disposed in a blood vessel. A method of manufacturing a catheter having a blade tube in which a reinforcing blade is disposed,
An end tube is disposed on at least one end side of the blade tube to abut the end surfaces in the axial direction, and after covering the both tubes of the blade tube and the end tube, extrapolating the tube, When heating and welding the extrapolated portion of the cover tube in the blade tube and the end tube, the amount of heat applied to the outer end portion in the axial direction of the end tube in the cover tube is adjusted with the blade tube in the cover tube. A method for manufacturing a catheter, wherein the amount of heat applied to a portion to be abutted with the end tube is larger. When heating and welding the extrapolated portion of the cover tube in the blade tube and the end tube, the amount of heat applied to the inner side portion of the cover tube in the axial direction from the abutting portion of the blade tube with the end tube The method for manufacturing a catheter according to claim 9, wherein the amount of heat applied to a portion where the blade tube and the end tube in the covered tube are abutted is increased. In a catheter having a blade tube with a reinforcing blade,
The cover tube is extrapolated to the blade tube, the cover tube protrudes from the axial end of the blade tube, and the protruding portion of the cover tube from the axial end of the blade tube is viewed in the axial direction. A catheter overlying the end face of the blade tube. The catheter according to claim 11, wherein an inner peripheral surface of the protruding portion of the covered tube is positioned on an inner peripheral side with respect to the reinforcing blade disposed on the blade tube. The catheter according to claim 11 or 12, wherein an outer diameter of the protruding tip of the covered tube is equal to or smaller than an outer diameter of the blade tube. The catheter according to any one of claims 11 to 13, wherein the protruding portion of the covered tube has a tapered portion whose outer diameter gradually decreases toward the protruding tip. The catheter according to any one of claims 11 to 14, wherein the protruding portion of the covering tube has a thickness dimension larger than that of a portion extrapolated to the blade tube. The catheter according to any one of claims 11 to 15, wherein the catheter is a delivery catheter that delivers a filter to a predetermined position in a blood vessel. The catheter according to any one of claims 11 to 16, wherein the protruding portion of the covered tube overlaps with an end face in the axial direction of the blade tube. The catheter according to any one of claims 11 to 17, wherein a contrast marker is provided on an outer peripheral surface of a distal end portion of the blade tube, and the contrast marker is covered with the covering tube.

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