JP6955189B2 - Manufacturing method of stent delivery catheter and stent delivery catheter - Google Patents

Description

The present invention relates to a stent delivery catheter for delivering a stent to a stenotic site in a lumen and a method for manufacturing a stent delivery catheter.

Conventionally, when an abnormality such as stenosis or occlusion occurs in a lumen such as a blood vessel, for example, a stent delivery catheter is used to deliver the stent to a lesion in the lumen, and the stent is expanded and pressed against the lumen wall. As a result, stent treatment is performed to keep the lumen in a dilated state. Such stents have a small diameter when inserted into the lumen, but are expanded and placed in the lumen. Examples of the method for expanding the diameter of the stent in the lumen include self-expansion using a shape memory material, mechanical expansion, and expansion using a balloon.

That is, when the stent is expanded by a balloon, generally, the balloon is folded with respect to the tip end portion of the shaft as in the stent delivery catheter described in Japanese Patent Application Laid-Open No. 2014-61191 (Patent Document 1). Along with the extrapolation, a stent is extrapolated and attached to the folded balloon to perform a diameter reduction treatment (crimp). Then, the tip portion of the stent delivery catheter is inserted into the lesion portion in the lumen to expand the balloon, so that the stent extrapolated to the balloon is expanded in diameter and pressed against the lumen wall. The stent is then placed in the lumen by contracting the balloon and removing the catheter.

By the way, as the stent to be placed in the lumen, for example, a stent having a skeletal structure in which one linear body is continuously extended in a spiral or tubular shape in the circumferential direction while being folded back in the axial direction is adopted. Then, the stent is mounted on the balloon and subjected to the diameter reduction treatment, so that the stent is fitted and held on the balloon.

However, depending on the material of the balloon or the stent, the skeletal structure or the skeletal design of the stent, it may be difficult to obtain a sufficient fixing force by fitting the stent to the balloon. In particular, in order to reduce thrombus slippage and omission, it is not desirable to form a gap between the skeletons of the stent as much as possible. The fixing force of is not enough. As a result, the stent may be misaligned with respect to the balloon when the stent is inserted or removed into the lumen.

Japanese Unexamined Patent Publication No. 2014-61191

The present invention has been made in the background of the above circumstances, and the problem to be solved is a stent delivery catheter and a stent delivery catheter having a novel structure capable of efficiently improving the fixing force of the stent to the balloon. To provide a manufacturing method for.

Hereinafter, aspects of the present invention made to solve such problems will be described. The components adopted in each of the following aspects can be adopted in any combination as much as possible.

The first aspect of the present invention is a stent delivery catheter in which a stent having a skeletal structure extending in the circumferential direction while being folded back in the axial direction is attached to a balloon provided at the tip of the shaft in an extrapolated state. , in the axial direction both end portions of the stent, with the reduced diameter portion of the inner diameter is smaller with the axial length of the annular body located axially opposite end portions that put on the skeletal structure is provided, the stent The skeletal structure is formed with a plurality of connecting portions that connect axially adjacent portions to each other, and the axially both end portions of the stent are smaller in the circumferential direction of the stent than the axially intermediate portions of the stent. It is characterized in that the connecting portion is provided with a separation distance.

According to the stent delivery catheter having a structure according to this embodiment, when the stent is attached to the balloon, the stent shaft is provided with a reduced diameter portion having a reduced inner diameter at both ends in the axial direction of the stent. Both ends of the direction bite into the balloon, and the stent can be firmly fixed to the balloon. In particular, since the diameter-reduced portions are provided at both ends in the axial direction of the stent, the axial displacement and detachment of the stent with respect to the balloon can be effectively prevented. Further, such reduced diameter portion is, since it is provided with an axial length of the annular body located axially opposite end portions, regions biting into the balloon is sufficiently ensured, the effect of preventing the positional deviation or dropping stable Can be demonstrated. Further, according to the stent delivery catheter having a structure according to this embodiment, more connections are formed at both ends in the axial direction of the stent than in the intermediate portion in the axial direction, so that both ends in the axial direction of the stent are formed. It is easy to stably form a reduced diameter portion, and the deformation rigidity of both ends in the axial direction of the stent is increased, while the flexibility of the intermediate portion in the axial direction is ensured. Therefore, even when the stent is placed in the bent part of the lumen, not only the deformation of the stent that follows the shape of the lumen is stably realized, but also the displacement in the lumen is effectively prevented. Can be done.

In the second aspect of the present invention, in the stent delivery catheter according to the first aspect, the skeletal structure of the stent is formed by a linear body that extends spirally in the circumferential direction as a whole while being folded back in the axial direction. It is something that is.

According to the stent delivery catheter having a structure according to this embodiment, the skeleton structure of the stent is formed by a linear body that extends spirally in the circumferential direction as a whole while being folded back in the axial direction, so that the skeleton is formed when the diameter of the stent is reduced. The gap between them can be reduced, and a stent with a high skeletal density can be designed. In that case, it is difficult for the balloon to enter the gap by reducing the diameter of the stent, but the stent delivery catheter having a structure according to this embodiment can improve the fixing force of the stent to the balloon.

A third aspect of the present invention is the stent delivery catheter according to the second aspect, as the inclination angle of the spiral of the spirally extending linear body with respect to the axial direction of the stent approaches the axial end. It is designed to grow gradually and approach vertical.

According to the stent delivery catheter having a structure according to this embodiment, the inclination angle of the spiral of the linear body gradually increases as it approaches the axial end and approaches the vertical, so that the inclination angle of the spiral becomes. Compared to the case where the stent is made smaller, it is easier to form reduced diameter portions at both ends in the axial direction, and when the stent is placed in the lumen, the axial end portion of the stent is greatly deformed and rises to the outer peripheral side. Etc. can be effectively prevented.

A fourth aspect of the present invention is the stent delivery catheter according to any one of the first to third aspects, wherein a thick portion having a large thickness dimension of the skeletal structure at both ends in the axial direction of the stent. Is provided, and the reduced diameter portion is formed by defining the outer diameter dimension of the stent on the outer peripheral surface of the thick portion.

According to the stent delivery catheter having a structure according to this embodiment, thick portions having a large thickness dimension of the skeletal structure are provided at both ends in the axial direction of the stent. When the stent protrudes to the outer peripheral side, the diameter of the stent is reduced so that the outer peripheral surface of both ends (thick portion) in the axial direction becomes flat with the outer peripheral surface of the intermediate portion in the axial direction. Is reduced in diameter to the inner circumference side. As a result, when the stent is attached to the balloon, the outer diameter of the stent is defined on the outer peripheral surface of the thickened portion, and the inner diameters of both ends in the axial direction are reduced by the amount of the thickened portion to reduce the diameter of the stent. Is configured. Further, even when the thick portion protrudes toward the inner circumference side with respect to the intermediate portion in the axial direction (when the outer diameter dimension is substantially constant in the axial direction), the outer diameter dimension of the stent is specified on the outer peripheral surface of the thick portion. At the same time, the reduced diameter portion is formed by the thick portion.

A fifth aspect of the present invention is the stent delivery catheter according to any one of the first to third aspects, wherein protrusions are formed on the outer peripheral surface of the skeletal structure at both ends in the axial direction of the stent. The reduced diameter portion is formed by defining the outer diameter dimension of the stent on the protruding tip surface of the protruding portion.

According to the stent delivery catheter having a structure according to this aspect, by providing the protrusions on the outer peripheral surfaces of both ends in the axial direction of the stent, the protruding tip surface of the protrusions protrudes to the outer peripheral side as compared with the intermediate portion in the axial direction. By performing the diameter reduction treatment on the stent, both ends in the axial direction having the protrusions are on the inner peripheral side until the protruding tip surface of the protrusion and the outer peripheral surface of the intermediate portion in the axial direction become flat. The diameter is reduced to. As a result, when the stent is attached to the balloon, the outer diameter of the stent is defined by the protruding tip surface of the protrusion, and the inner diameters of both ends in the axial direction are reduced by the protruding dimension of the protrusion to reduce the diameter. It is composed.

A sixth aspect of the present invention is to manufacture a stent delivery catheter by externally attaching a stent having a skeletal structure extending in the circumferential direction while folding back in the axial direction to a balloon provided at the tip of the shaft. At that time, a state in which an inner protective tube covering the entire length in the axial direction and an outer protective tube covering both ends in the axial direction of the stent from the outside of the inner protective tube are attached to the stent externally inserted into the balloon. Then, from the outside of the inner protective tube and the outer protective tube, the stent was reduced in diameter with a crimp device to provide a contractile portion in which the inner diameter dimension was reduced, and the stent was attached to the balloon and inside the stent. A method for manufacturing a stent delivery catheter, which comprises removing the protective tube and the outer protective tube to obtain the stent delivery catheter.

According to the method for manufacturing a stent delivery catheter according to this embodiment, an outer protective tube is attached to both ends in the axial direction of the stent in addition to the inner protective tube. Therefore, when the diameter is reduced by the crimp device, both ends in the axial direction of the stent are attached. The amount of diameter reduction is increased by the amount of the outer protective tube as compared with the axial intermediate portion. As a result, when the stent is attached to the balloon, both ends in the axial direction of the stent are made to bite into the balloon, and the stent can be effectively prevented from being displaced or dropped from the balloon.

A seventh aspect of the present invention is the method for manufacturing a stent delivery catheter according to the sixth aspect, wherein a plurality of connecting portions for connecting axially adjacent portions are formed in the skeletal structure of the stent. In the axially intermediate portion of the stent, the connecting portion is provided with a larger separation distance in the circumferential direction of the stent than the axially both end portions of the stent.

According to the method for manufacturing a stent delivery catheter according to this embodiment, since more connections are formed at both ends in the axial direction of the stent than at the intermediate portion in the axial direction, the deformation rigidity of both ends in the axial direction of the stent is formed. Is increased. Therefore, when the diameter is uniformly reduced in the axial direction as in the conventional stent delivery catheter, the diameter of both ends in the axial direction is less likely to be reduced as compared with the intermediate portion in the axial direction. By attaching an outer protective tube to increase the amount of diameter reduction, the stent can be stably bitten into the balloon even at both ends in the axial direction with high deformation rigidity, effectively preventing the stent from shifting or falling off with respect to the balloon. obtain.

An eighth aspect of the present invention is the above sixth or method of manufacturing a stent delivery catheter according to a seventh aspect, in the axial end portion of the stent, located axially opposite end portions that put on the skeletal structure The outer protective tube is attached with an axial length of the annular body to be formed.

According to the method of manufacturing a stent delivery catheter according to this embodiment, since the outer protective tube is mounted with an axial length of the annular body located in the axially opposite end portions that put the skeletal structure of the stent, diameter Nioite stent A sufficient axial length of the region to be formed can be sufficiently secured to efficiently improve the fixation force of the stent to the balloon.

According to the method for manufacturing a stent delivery catheter having a structure according to the present invention and a stent delivery catheter according to the present invention, both ends in the axial direction of the stent are made to bite into the balloon when the stent is attached to the balloon. The fixation force of the stent to the balloon can be efficiently improved.

The front view which shows the whole of the stent delivery catheter as one Embodiment of this invention. The front view which shows the main part of the stent delivery catheter shown in FIG. FIG. 2 is a vertical cross-sectional view of the stent delivery catheter shown in FIG. It is a cross-sectional view of the stent delivery catheter shown in FIG. 1, and corresponds to the IV-IV cross section in FIG. The development view which shows one specific example of the stent which can be adopted in this invention open at one place in the circumferential direction. FIG. 5 is an enlarged view showing a main part of FIG. The explanatory view for demonstrating the manufacturing method of the stent delivery catheter as the method of this invention. FIG. 3 is a vertical cross-sectional view of a stent delivery catheter as another aspect of the present invention, which corresponds to FIG. It is a vertical cross-sectional view of the stent delivery catheter as still another aspect of the present invention, and is the figure corresponding to FIG. The development view which shows another specific example of the stent which can be adopted in this invention open at one place in the circumferential direction.

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

First, FIGS. 1 to 4 show a stent delivery catheter 10 as an embodiment of the present invention. The stent delivery catheter 10 includes a balloon catheter 12, and the balloon 16 is attached to the tip end portion of the shaft 14 in the balloon catheter 12. Further, the stent 18 is attached to the balloon 16 in a reduced diameter state, and the stent 18 is expanded by expanding the balloon 16 after delivering the stent 18 to a narrowed portion of a lumen such as a blood vessel. , The narrowed part of the lumen is expanded. In the following description, the axial direction means the left-right direction in FIG. 1, which is the central axial direction of the catheter 10. The distal end side refers to the left side in FIG. 1 which is the side of the catheter 10 to be inserted into the lumen, while the proximal end side refers to the right side in FIG. 1 which is the side operated by the user in the catheter 10. Say.

More specifically, the balloon catheter 12 has a structure in which the distal shaft 20 and the proximal shaft 22 are axially connected, and the distal shaft 20 and the proximal shaft 22 are connected in the axial direction. The shaft 14 of the balloon catheter 12 is configured by the above. Further, a connector 24 is connected to the proximal end side of the balloon catheter 12 (the proximal end side of the proximal shaft 22).

The proximal shaft 22 has a single-tube structure extending in the axial direction, and is formed of, for example, a synthetic resin such as a polyamide elastomer or a metal such as stainless steel. Then, the lumen of the proximal shaft 22 is communicated with the external space through the connector 24.

On the other hand, the distal shaft 20 has a double pipe structure of an inner shaft 26 and an outer shaft 28 as a whole. That is, the outer diameter dimension of the inner shaft 26 is smaller than the inner diameter dimension of the outer shaft 28, the base end of the inner shaft 26 is inserted into the outer shaft 28, and the tip of the inner shaft 26 is the tip of the outer shaft 28. Protruding from.

Here, the outer shaft 28 has a tubular shape extending in the axial direction, and is formed of a synthetic resin such as a polyamide elastomer. The outer diameter of the outer shaft 28 is substantially equal to that of the proximal shaft 22, and the base end of the outer shaft 28 and the tip of the proximal shaft 22 are connected to each other. As a result, the lumen of the outer shaft 28 and the lumen of the proximal shaft 22 are communicated with each other.

Further, the inner shaft 26 includes an inner shaft main body 30. The inner shaft main body 30 has a tubular shape extending in the axial direction as a whole, and is made of a synthetic resin such as a polyamide elastomer. A tip tip 32 is fixed to the tip of the inner shaft body 30. The tip 32 has a cylindrical shape and has substantially the same outer diameter and inner diameter as the inner shaft main body 30. On the other hand, the base end of the inner shaft body 30 is bent and opens on the outer peripheral surface of the outer shaft 28. As a result, the lumen of the inner shaft body 30 is a lumen that opens at the tip of the catheter 10 and the intermediate portion in the axial direction, and a guide wire lumen through which a guide wire for guiding the catheter 10 is inserted. 34 is configured. That is, the stent delivery catheter 10 of the present embodiment is a rapid exchange type catheter in which the guide wire lumen is shorter than the total length in the axial direction of the catheter. However, the stent delivery catheter according to the present invention may be an over-the-wire catheter.

The inner shaft 26 of the present embodiment is provided with a large diameter portion 36 having a larger outer diameter than the other portions in the protruding portion from the outer shaft 28. In particular, in the present embodiment, the large diameter portion 36 is configured by mounting the covering member 38 on the outer peripheral surface of the inner shaft main body 30.

The covering member 38 has a substantially tubular shape extending in the axial direction, and in the present embodiment, the covering member 38 has an axial dimension smaller than the axial dimension from the tip of the outer shaft 28 to the tip tip 32, and also has an axial dimension. It has a substantially constant outer diameter dimension over the entire length in the axial direction. The material of the covering member 38 is not limited in any way, but it is preferable to use a material having a hardness lower than that of the inner shaft main body 30, and for example, a synthetic resin such as polyamide elastomer, polyester elastomer, or polyurethane is preferable. Can be adopted in.

Further, the method of mounting the covering member 38 on the inner shaft main body 30 is not limited in any way, but for example, a synthetic resin material dissolved in a solvent is applied to the inner shaft main body 30 and dried, or has heat shrinkage. By externally inserting the tubular member into the inner shaft main body 30 and applying heat, the tubular member may be brought into close contact with the inner shaft main body 30.

Further, the radial width dimension α (see FIG. 4) of the covering member 38 is not particularly limited, but for example, the outer diameter dimension φA (see FIG. 4) of the inner shaft main body 30 is 0.5 mm to 0. When the outer diameter dimension φB (see FIG. 4) of the balloon 16 when the diameter is reduced to 6 mm is 2 mm to 3 mm, it is preferably set within the range of 0.1 mm to 0.5 mm. When the outer diameter dimension of the inner shaft body, the balloon at the time of diameter reduction, or both of them is out of the above range, the radial width dimension of the covering member can be appropriately set.

A balloon 16 is attached to the outer peripheral side of the large diameter portion 36 at the tip end portion of the inner shaft 26 having such a structure. The balloon 16 can be expanded and contracted by introducing and discharging a fluid inside, and is a tubular or bag-shaped member formed of a thin-film synthetic resin, a rubber film, or the like. The material of the balloon 16 is not limited in any way, but in the present embodiment, the balloon 16 is made of nylon resin, and the balloon 16 is subjected to the pressure applied when the fluid is supplied to the inside and expanded. It is said to be a low compliant balloon with a small change in outer diameter. Further, in order to suppress the influence on the flexibility of the inner shaft 26, it is desirable that the balloon 16 is as thin as possible while ensuring the strength to expand the diameter of the stent 18 at the time of expansion.

Then, the tip of the balloon 16 is fixed to the tip of the inner shaft body 30 and the outer peripheral surface of the tip tip 32 by adhesion or the like, while the base end of the balloon 16 is fixed to the outer peripheral surface of the tip of the outer shaft 28 by adhesion or the like. ing. Therefore, the space between the inner shaft main body 30 and the outer shaft 28 in the radial direction is communicated with the internal space of the balloon 16, while being communicated with the external space through the proximal shaft 22 and the connector 24. As a result, fluid can be introduced and discharged from the external space into the internal space of the balloon 16 through the space between the inner shaft body 30 and the outer shaft 28 in the radial direction, and from the internal space of the balloon 16 to the external space. The entire cavity is a supply / discharge lumen 40 that supplies / discharges fluid to / from the balloon 16.

Further, substantially cylindrical markers 42 and 42 are extrapolated on the outer peripheral surface of the inner shaft main body 30 at both ends in the axial direction of the balloon 16. These markers 42, 42 are formed of a material such as platinum, which is opaque to X-rays.

As shown in FIG. 4, the balloon 16 in the initial state is in a wrapping state in which the balloon 16 is folded in the circumferential direction so as to overlap in the radial direction. In particular, in the present embodiment, since the large diameter portion 36 is provided at the tip portion of the inner shaft 26 and the balloon 16 is mounted on the outer peripheral side of the large diameter portion 36, the large diameter portion is provided on the inner shaft. The outer diameter of the balloon 16 in the wrapped state is larger than that in the case where it is not provided. A stent 18 is extrapolated and attached to the balloon 16 in such a wrapping state.

The stent 18 has a substantially cylindrical shape extending in the axial direction as a whole, and is attached to the outer peripheral side of the large diameter portion 36 having a large diameter in the inner shaft 26. The shape of the stent is not limited as long as it has a skeletal structure that extends in the circumferential direction while being folded back in the axial direction, but the stent 18 of the present embodiment is shown in FIGS. 5 and 6 as a specific example. As shown in the developed view, one linear body 44 has a skeletal structure in which one linear body 44 reciprocates in the axial direction with a substantially constant amplitude and extends spirally in the circumferential direction as a whole. That is, in the present embodiment, the thickness dimension (radial width dimension) of the stent 18 is substantially equal over the total length in the axial direction.

Further, the number of waves (number of turns) in the circumferential direction in one round, that is, the number of repeating units of the periodic structure in one round of the linear body 44 is larger than that of a general coronary stent, for example, 10 to 12 waves. Therefore, the stent 18 of the present embodiment has 12 waves. The material of the stent is not limited in any way, but the stent 18 of the present embodiment is made of a cobalt-chromium alloy. Further, the width dimension of the skeletal structure (strut) of the stent 18, that is, the width dimension β of the linear body 44 (see FIG. 4) is set within the range of 80 μm to 100 μm, although it is not limited in any way. Is preferable. Furthermore, it is preferable that the maximum outer diameter dimension φC (see FIG. 4) of the stent 18 when attached to the balloon 16 is set within the range of 1.0 mm to 1.3 mm.

Then, in the stent 18 of the present embodiment, as shown in FIG. 6, the inclination angle of the spiral with respect to the axial direction of the linear body 44 gradually changes at both end portions. Specifically, the inclination angle of the spiral of the linear body 44 gradually increases toward both ends in the axial direction of the stent 18 so as to approach vertical (90 degrees). In particular, in the present embodiment, the inclination angle of the spiral of the linear body 44 is substantially vertical at both ends in the axial direction of the stent 18.

That is, in the stent 18 of the present embodiment, as shown by the broken line in FIG. 6, in the axially both ends of the stent 18, for example, in the region extending from the axial end of the linear body 44 to four circumferential directions The reciprocating amplitude of the shape 44 in the axial direction is gradually changed, whereby the inclination angle of the spiral of the linear body 44 is changed. Specifically, in the above region, the reciprocating amplitude in the axial direction of the linear body 44 is gradually reduced toward the axial end portion.

However, the inclination angle of the spiral of the linear body 44 does not have to reach the vertical even near the tip of the stent 18 in the axial direction, and may reach the inclination angle slightly beyond the vertical. Preferably, the tilt angle of the spiral of the linear body 44 is preferably set to reach 80 degrees or more at the axial tip of the stent 18, and more preferably to reach a value of 85 to 90 degrees. Further, the region in which the inclination angle of the spiral of the linear body 44 gradually changes may be set to one or more turns in the circumferential direction of the stent 18, but is preferably set to two or more turns, and more preferably three. It is set to change over the lap. As a result, it is possible to avoid a sudden change in the inclination angle of the spiral of the linear body 44, for example, set the amount of change in the inclination angle per circumference to 5 degrees or less, and deform or expand the stent 18 as a whole. It can be generated more smoothly.

The inclination of the spiral is shown by a two-point chain line in the figure, for example, connecting the center in the axial direction of each adjacent straight line portion of the linear body 44 in the central portion in the direction perpendicular to the axis (vertical direction) in FIG. The spiral angle is the value of "(90 degrees)-(lead angle of the spiral)". In FIG. 6, the inclination angle of the spiral is shown as the angle formed by the central axis L extending in the axial direction (left-right direction in FIG. 6) indicated by the alternate long and short dash line: θ.

As shown in FIG. 2, in the stent 18, one linear body 44 constitutes a plurality of annular bodies 46, and the plurality of annular bodies 46 are arranged in parallel in the axial direction. It is said to be a structure. In the present embodiment, as shown in FIGS. 5 and 6, the annular bodies 46 and 46 adjacent to each other in the axial direction are connected and reinforced by a connecting portion 48 connecting the bent portions of the linear bodies 44 to each other. A plurality of such connecting portions 48 are provided in the axial direction and the circumferential direction of the stent 18, and in particular, in the present embodiment, the connecting portion 48a is appropriate in the circumferential direction in one circumferential portion in the circumferential direction at both end portions in the axial direction. Although five are formed at various locations, one or two connecting portions 48b are formed at appropriate locations in the circumferential direction in one circumferential portion in the circumferential direction in the intermediate portion in the axial direction. That is, the connecting portions 48b, 48b that are adjacent in the circumferential direction in the axial intermediate portion of the stent 18 are provided at both end portions in the axial direction with a larger separation distance in the circumferential direction than the connecting portions 48a, 48a that are adjacent in the circumferential direction. ..

In the initial state, the stent 18 is reduced in diameter by, for example, a crimp device 50 (see FIG. 7C), and is extrapolated and attached to the balloon 16 as shown in FIG. As the crimp device 50, a commercially available device can be adopted, and the crimp device 50 is not particularly limited, but includes, for example, a cylindrical mold 52 (see FIG. 7C), and the mold 52 is provided. It is preferable that the inner surface 54 (see FIG. 7C) of the above is a flat surface extending in the circumferential direction. The mold of the crimp device may be composed of, for example, a pair of halves and can be opened and closed by a hinge.

In particular, in the present embodiment, since the stent 18 is extrapolated and mounted on the balloon 16 whose outer diameter is enlarged by the large diameter portion 36 of the inner shaft 26, the diameter of the stent becomes too small when the diameter is reduced. Problems such as overlapping of adjacent linear bodies can be avoided.

Here, both ends in the axial direction of the stent 18 mounted on the balloon 16 are reduced diameter portions 56, 56 in which the inner diameter dimension of the stent 18 is reduced. In the present embodiment, the diameter-reduced portions 56, 56 are configured by reducing the outer diameter dimension and the inner diameter dimension of the annular bodies 46a, 46a located at both ends in the axial direction. That is, in the present embodiment, the diameter-reduced portions 56 and 56 are provided at both ends of the stent 18 in the axial direction with an axial length corresponding to one circumference in the circumferential direction of the skeletal structure.

It should be noted that the diameter reduction amount γ with respect to the axial intermediate portion in the reduced diameter portions 56, 56 (inner diameter dimension φD (see FIG. 3) of the axial intermediate portion and the inner diameter dimension φE (see FIG. 3) in the reduced diameter portions 56, 56). The difference (φD−φE)) is not limited in any way. It is preferably set within the range of ~ 95%. Specifically, for example, when the stent 18 is used for a coronary artery, the inner diameter dimension φD of the stent 18 when attached to the balloon 16 is 0.8 mm to 1.2 mm, while the reduced diameter portions 56, 56. It is preferable that the reduced diameter amount γ in the above is set within the range of 0.05 mm to 0.2 mm. Alternatively, when the stent 18 is used for peripheral blood vessels, the inner diameter dimension φD of the stent 18 when attached to the balloon 16 is 1.0 mm to 1.6 mm, while the diameters of the reduced diameter portions 56 and 56 are reduced. It is preferable that the amount γ is set within the range of 0.1 mm to 0.5 mm. That is, although it depends on the material and shape of the stent, the number of turns, etc., if φE / φD is smaller than 80%, the skeletal structure (struts) of the stent may overlap each other and float up when the stent is crimped. be. On the other hand, when φE / φD is larger than 95%, a sufficient fixing force for the balloon, which will be described later, may not be obtained.

The method for manufacturing the stent delivery catheter 10 having the above structure is not limited in any way, but a specific example of the manufacturing method will be described below with reference to FIGS. 7 (a) to 7 (d).

First, the balloon catheter 12 and the stent 18 are prepared respectively. The balloon catheter 12 and the stent 18 can be manufactured by a conventionally known method.

Then, as shown in FIG. 7A, the stent 18 is externally inserted onto the balloon 16 on the outer peripheral side of the large diameter portion 36 of the inner shaft 26, and the diameter is reduced (crimped) with a relatively weak force. As a result, the stent 18 is temporarily fixed on the balloon 16. In such a temporarily fixed state, the stent 18 can be moved in the axial direction. For example, when the stent 18 is displaced from the large diameter portion 36, the stent 18 is moved in the axial direction and positioned on the large diameter portion 36. Can be made to.

Next, as shown in FIG. 7B, the inner protective tube 58 is extrapolated and attached to the stent 18 temporarily fixed on the balloon 16. The inner protective tube 58 is a tube formed of a thermoplastic resin such as polyethylene, and is formed of PTFE (polytetrafluoroethylene) in the present embodiment. The inner protective tube 58 has an inner diameter dimension slightly larger than the outer diameter dimension of the temporarily fixed stent 18, and has an axial dimension larger than that of the stent 18, and is the axis of the stent 18. The inner protective tube 58 is extrapolated and mounted over the entire length in the direction. When the protective tube made of resin is attached over the substantially overall length of the stent in the axial direction, the inner surface of the mold of the crimping device and the outer peripheral surface of the stent come into contact with each other during crimping, and the stent or the stent or the outer surface of the stent abuts due to friction. Damage to the mold can be prevented.

Subsequently, the outer protective tubes 60 and 60 are extrapolated and mounted on the outer side of the inner protective tube 58 at both ends in the axial direction of the stent 18. The outer protective tubes 60 and 60 are tubes made of the same material as the inner protective tube 58, and have an inner diameter dimension slightly larger than the outer diameter dimension of the inner protective tube 58. Further, the outer protective tubes 60, 60 have a certain axial length, and in the present embodiment, the outer protective tubes 60, 60 are on the outer peripheral side of the annular bodies 46a, 46a located at both ends in the axial direction. Is extrapolated and attached to the inner protective tube 58. That is, the outer protective tubes 60, 60 are extrapolated and attached to the inner protective tube 58 at both ends in the axial direction of the stent 18 with a length dimension corresponding to one circumference of the stent 18 in the circumferential direction.

Then, as shown in FIG. 7 (c), the crimping device 50 executes crimping with the inner protective tube 58 and the outer protective tubes 60 and 60 extrapolated and attached to the stent 18. That is, by pressing the inner surface 54 of the mold 52 of the crimp device 50 against the outer peripheral surfaces of the inner protective tube 58 and the outer protective tubes 60, 60, pressure is applied to the stent 18 from the outside to reduce the diameter of the stent 18 and to the balloon 16. On the other hand, the stent 18 is fixed. At the time of such crimping, for example, the mold 52 is heated to soften the balloon 16 by heating, or the fluid is supplied into the balloon 16 through the supply / discharge lumen 40 from the inside with respect to the stent 18. It is also preferable to apply pressure.

Since the inner surface 54 of the mold 52 is made flat by such crimping, the diameter is reduced until the outer peripheral surface of the inner protective tube 58 and the outer peripheral surfaces of the outer protective tubes 60 and 60 become flat surfaces. That is, the amount of contraction of the annular bodies 46a and 46a located at both ends in the axial direction is made larger than that of the annular body 46 located in the intermediate portion in the axial direction by the amount to which the outer protective tubes 60 and 60 are attached. The outer diameter dimension and inner diameter dimension of the annular bodies 46a and 46a located at both ends are made smaller than those of the annular body 46 located at the intermediate portion in the axial direction. As a result, the reduced diameter portions 56, 56 are formed by the annular bodies 46a, 46a located at both ends in the axial direction.

Finally, as shown in FIG. 7 (d), the inner protective tube (58) and the outer protective tube (60, 60) are removed from the stent 18. Thereby, the stent delivery catheter 10 can be manufactured.

The stent delivery catheter 10 having the above structure is inserted into a lumen such as a blood vessel, and the stent 18 is delivered to the stenosis site. Then, by expanding the balloon 16 with the stent 18 located on the inner peripheral side of the stenotic part of the lumen, the stent 18 is deformed to the enlarged diameter state and the stenotic part is expanded. Further, by placing the stent 18 in the lumen, the expanded state of the lumen is maintained by the stent 18.

Here, in the stent delivery catheter 10 of the present embodiment, since the diameter-reduced portions 56 and 56 having a reduced inner diameter are provided at both ends in the axial direction of the stent 18, when the stent 18 is attached to the balloon 16. , The reduced diameter portions 56, 56 are made to bite into the balloon 16, and the fixing force of the stent 18 to the balloon 16 at both ends in the axial direction is improved. Therefore, axial misalignment and dropout of the stent 18 with respect to the balloon 16 can be effectively prevented.

In particular, since the reduced diameter portions 56, 56 are composed of the annular bodies 46a, 46a at both ends in the axial direction, that is, they are formed with an axial length equivalent to one circumference in the circumferential direction, the balloon 16 The axial length of the biting region is sufficiently secured, and the fixed state of the stent 18 with respect to the balloon 16 can be stably maintained.

Further, in the stent 18 of the present embodiment, since both end faces of the stent 18 are close to perpendicular to the axial direction, the axial end of the stent 18 also when the stent 18 passes through the bent portion of the lumen. It is possible to effectively prevent the portion from rising locally.

Further, in the stent 18 of the present embodiment, since more connecting portions 48 for connecting the annular bodies 46 and 46 in the axial direction are formed in both end portions in the axial direction than in the intermediate portion in the axial direction, the stent 18 is formed in the axial direction. Sufficient deformation rigidity of both ends is ensured, and flexibility of the intermediate portion in the axial direction is also ensured. As a result, the stent 18 can be stably placed even in a bending lumen, for example, without being displaced. Further, since the deformation rigidity of both ends in the axial direction is increased, it is difficult to reduce the diameter of both ends in the axial direction by the conventional crimp method. By externally mounting 60 and 60 and crimping, it is effective even at both ends in the axial direction with high deformation rigidity, and local strain concentration is suppressed on the circumference, and the entire circumference is contracted almost uniformly. Can be calibrated.

Although the embodiments of the present invention have been described above, the present invention is not limitedly interpreted by the specific description in the embodiments, and various changes, modifications, improvements, etc. are made based on the knowledge of those skilled in the art. It can be carried out in the form of adding.

For example, in the above embodiment, the inner protective tube 58 and the outer protective tubes 60, 60 are manufactured separately, and after the inner protective tube 58 is extrapolated and attached to the stent 18, the outer protective tubes 60, 60 are attached to the inner protective tube. Although it was extrapolated to 58, it is not limited to such a mode. That is, one protective tube may be adopted in which the outer diameter dimension, the inner diameter dimension, or both of the both end portions in the axial direction are larger than the intermediate portion in the axial direction.

However, the outer diameter dimension and the inner diameter dimension of the protective tube may be substantially uniform over the entire length in the axial direction. That is, as in the stent delivery catheter 70 shown in FIG. 8, thick portions 74 and 74 having a thickness larger than that of the axial intermediate portion may be provided at both ends in the axial direction in the skeletal structure of the stent 72. .. Before the diameter reduction, when the thick portion 74, 74 protrudes to the outer peripheral side from the intermediate portion in the axial direction, the thick portion 74, In short, the outer diameter dimension of the stent 72 becomes substantially constant over the entire length in the axial direction until the outer peripheral surfaces 76, 76 of the thick portions 74, 74 become flat with the outer peripheral surface 78 of the axial intermediate portion. The diameter is reduced to. That is, the thicker portions 74, 74 are reduced in diameter from the axial intermediate portion by the amount of the thicker thickness than the axial intermediate portion, and the inner diameter dimension of both end portions in the axial direction is reduced. As a result, the reduced diameter portions 80, 80 are formed, that is, the outer diameter dimensions of the stent 72 are defined by the outer peripheral surfaces 76, 76 of the thickened portions 74, 74, so that the reduced diameter portions 80, 80 are formed. Is configured. In this embodiment, the annular bodies 46a and 46a at both ends in the axial direction are thicker than the annular bodies 46 at the intermediate portion in the axial direction, and the reduced diameter portions 80 and 80 are the axes for one circumference in the circumferential direction. It is formed with a directional length.

Further, before the diameter is reduced, when the thick portion protrudes to the inner peripheral side from the intermediate portion in the axial direction, a protective tube having a uniform diameter is externally inserted to reduce the diameter, so that the diameter can be reduced when the balloon is attached. A reduced diameter portion having a reduced inner diameter is formed by these thick portions.

Alternatively, as in the stent delivery catheter 90 shown in FIG. 9, protrusions 96 and 96 may be provided on the outer peripheral surfaces 94 and 94 of the skeletal structure at both axially end portions of the stent 92. In this embodiment, by externally inserting and reducing the diameter of the protective tube having a uniform diameter, both ends in the axial direction of the stent 92 and the protruding tip surfaces 98 and 98 of the protrusions 96 and 96 are the outer peripheral surfaces of the intermediate portion in the axial direction. The diameter of the stent 92 is reduced until it becomes flat to 100, that is, the outer diameter of the stent 92 becomes substantially constant over the entire length in the axial direction. That is, the protrusions 96, 96 reduce the diameter of both ends in the axial direction by the amount of protrusion from the intermediate portion in the axial direction, and reduce the inner diameter dimension of both ends in the axial direction. As a result, the reduced diameter portions 102, 102 are formed, that is, the outer diameter dimension of the stent 92 is defined by the protruding tip surfaces 98, 98 of the protruding portions 96, 96, so that the reduced diameter portions 102, 102 is configured. In this embodiment, the protrusions 96, 96 are formed with axial lengths substantially equal to the annular bodies 46a, 46a at both ends in the axial direction, and the diameter-reduced portions are formed by the annular bodies 46a, 46a at both ends in the axial direction. 102, 102 are configured. Therefore, also in this embodiment, the reduced diameter portions 102, 102 are formed with an axial length corresponding to one circumference in the circumferential direction. Further, the protrusions 96, 96 may be continuously provided over the entire circumference in the circumferential direction, or may be partially formed in the circumferential direction.

In addition, before the diameter is reduced, if the protrusion protrudes toward the inner circumference side from the intermediate portion in the axial direction, a protective tube having a uniform diameter is externally inserted to reduce the diameter, so that the inner diameter is reduced when the balloon is attached to the balloon. Reduced diameter portions with reduced dimensions are formed by these protrusions.

However, in the present invention, the protective tube is not essential, and the outer peripheral surface of the stent may be directly crimped by a crimping device.

In the present invention relating to the stent delivery catheter, the reduced diameter portion need only have an axial length of at least one circumference in the circumferential direction of the stent, and is limited to one circumference in the circumferential direction as in the embodiment. It's not a thing.

Further, in the above-described embodiment, the large-diameter portion 36 is formed by extrapolating and mounting the tubular covering member 38 on the inner shaft main body 30, but the present invention is not limited to this mode. For example, the covering member may be band-shaped and wound around the inner shaft body to form a large diameter portion, or the inner shaft body may be partially thickened to form a large diameter portion. .. However, in the present invention, the large diameter portion of the inner shaft is not essential.

Further, the connecting portion connecting the annular body and the annular body in the intermediate portion in the axial direction may be a fragile portion that preferentially breaks when bent, for example, by reducing the thickness dimension and the width dimension. .. Thereby, the flexibility at the time of bending of the stent can be further ensured. However, when the skeletal structure of the stent is formed by a single linear body, the connecting portions at both end portions in the axial direction and the intermediate portions in the axial direction are not essential.

Even when the stent is provided with a connecting portion, the number of connecting portions and the forming position are not limited in any way. That is, in the above-described embodiment, five connecting portions 48a are provided at appropriate locations in the circumferential direction in one circumferential portion of the axial end of the stent 18, but the stent 110 shown in FIG. As described above, the connecting portion 112a may be continuously formed in the circumferential direction for each bent portion in one circumferential portion in the circumferential direction at the axial end portion. By providing more connecting portions in the axial end portion in this way, the axial end portion can be reduced in diameter more uniformly in the circumferential direction.

Furthermore, in the above-described embodiment, the skeletal structure of the stent is formed by a single linear body that is folded back in the axial direction and extends spirally in the circumferential direction as a whole, but is not limited to such an embodiment. .. That is, one linear body extends in the circumferential direction while folding back in the axial direction to form one annular body, and a plurality of annular bodies each consisting of one linear body are aligned in the axial direction to form a connecting portion. It may be a skeletal structure connected by.

Further, in the above-described embodiment, the inner surface 54 of the mold 52 of the crimp device 50 is a flat surface extending in the circumferential direction, but a protrusion may be provided on the inner surface of the mold so as to extend in the circumferential direction. In such a case, the reduced diameter portion can be formed without changing the thickness dimension of the protective tube or the stent. However, when the diameter of the stent is reduced, it may be crimped by a method other than the crimping device.

In the above embodiment, a stent for a coronary artery having a wave number of 10 to 12 has been exemplified, but the stent is not limited in any way. For example, a stent for peripheral blood vessels may be adopted as the stent, and in such a case, the wave number may be 18 to 24, for example.
The present invention originally includes the inventions described below, and the configuration and action / effect thereof will be added.
The present invention
(I) A stent delivery catheter in which a stent having a skeletal structure extending in the circumferential direction while folding back in the axial direction is attached to a balloon provided at the tip of the shaft in an extrapolated state, and is in the axial direction of the stent. A stent delivery catheter characterized in that both end portions are provided with diameter-reduced portions having an inner diameter reduced by at least one circumferential length in the circumferential direction of the skeletal structure.
(Ii) The stent delivery catheter according to (i), wherein the skeletal structure of the stent is formed by a linear body that is folded back in the axial direction and extends spirally in the circumferential direction as a whole.
(Iii) The stent delivery according to (ii), wherein the inclination angle of the spiral of the spirally extending linear body with respect to the axial direction of the stent gradually increases as it approaches the axial end portion and approaches the vertical direction. catheter,
(Iv) The skeletal structure of the stent is formed with a plurality of connecting portions that connect axially adjacent portions to each other, and the axial intermediate portion of the stent is more than the axially end portions of the stent. The stent delivery catheter according to any one of (i) to (iii), wherein the connecting portion is provided with a large separation distance in the circumferential direction of the stent.
(V) A thick portion having a large thickness dimension of the skeletal structure is provided at both ends in the axial direction of the stent, and the outer diameter dimension of the stent is defined by the outer peripheral surface of the thick portion. The stent delivery catheter according to any one of (i) to (iv), wherein the reduced diameter portion is formed.
(Vi) At both ends in the axial direction of the stent, protrusions are formed on the outer peripheral surface of the skeletal structure, and the outer diameter dimension of the stent is defined by the protruding tip surface of the protrusion to reduce the diameter. The stent delivery catheter according to any one of (i) to (iv), wherein the portion is composed of the stent delivery catheter.
(Vii) When a stent having a skeletal structure extending in the circumferential direction while being folded back in the axial direction is attached to a balloon provided at the tip of the shaft in an extrapolated state to manufacture a stent delivery catheter, the balloon is external to the balloon. An inner protective tube that covers the entire length in the axial direction and an outer protective tube that covers both ends in the axial direction of the stent from the outside of the inner protective tube are attached to the inserted stent. A method for manufacturing a stent delivery catheter, which comprises reducing the diameter of the stent with a crimp device from the outside of the outer protective tube and attaching the stent to the balloon.
(Viii) The skeletal structure of the stent is formed with a plurality of connecting portions that connect axially adjacent portions to each other, and the axial intermediate portion of the stent is more than the axially end portions of the stent. The method for manufacturing a stent delivery catheter according to (vii), wherein the connection portion is provided with a large separation distance in the circumferential direction of the stent.
(Ix) The manufacture of the stent delivery catheter according to (vii) or (viii), wherein the outer protective tube is attached to both axially end portions of the stent with an axial length corresponding to at least one circumferential circumference in the skeletal structure. Method,
Including inventions related to.
In the invention described in (i) above, when the stent is attached to the balloon, both ends in the axial direction of the stent are provided with reduced diameter portions having a reduced inner diameter, so that both ends in the axial direction of the stent are provided. It can bite into the balloon and firmly secure the stent to the balloon. In particular, since the diameter-reduced portions are provided at both ends in the axial direction of the stent, the axial displacement and detachment of the stent with respect to the balloon can be effectively prevented. Further, since the reduced diameter portion is provided with an axial length corresponding to at least one circumference in the circumferential direction, a sufficient area for biting into the balloon is sufficiently secured, and the effect of preventing the above-mentioned misalignment and falling off is stably exhibited. obtain.
In the invention described in (ii) above, the skeletal structure of the stent is formed by a linear body that is folded back in the axial direction and extends spirally in the circumferential direction as a whole, so that a gap between the skeletons is formed when the diameter of the stent is reduced. It can be made smaller and a stent with a high skeletal density can be designed. In that case, it is difficult for the balloon to enter the gap by reducing the diameter of the stent, but the stent delivery catheter having a structure according to this embodiment can improve the fixing force of the stent to the balloon.
In the invention described in (iii) above, since the inclination angle of the spiral of the linear body gradually increases and approaches the vertical as it approaches the axial end, the case where the inclination angle of the spiral is reduced. Compared to Can be prevented.
In the invention described in (iv) above, since more connecting portions are formed at both ends in the axial direction of the stent than at the intermediate portions in the axial direction, the diameter of the stent is stably reduced at both ends in the axial direction. It is easy to form a portion, and the deformation rigidity of both ends in the axial direction of the stent is increased, while the flexibility of the intermediate portion in the axial direction is ensured. Therefore, even when the stent is placed in the bent part of the lumen, not only the deformation of the stent that follows the shape of the lumen is stably realized, but also the displacement in the lumen is effectively prevented. Can be done.
In the invention described in (v) above, thick portions having a large thickness dimension of the skeletal structure are provided at both ends in the axial direction of the stent. In the case of protrusion, the diameter of the stent is reduced so that the thick portion is on the inner peripheral side until the outer peripheral surface of both ends (thick portion) in the axial direction becomes flat with the outer peripheral surface of the intermediate portion in the axial direction. The diameter is reduced to. As a result, when the stent is attached to the balloon, the outer diameter of the stent is defined on the outer peripheral surface of the thickened portion, and the inner diameters of both ends in the axial direction are reduced by the amount of the thickened portion to reduce the diameter of the stent. Is configured. Further, even when the thick portion protrudes toward the inner circumference side with respect to the intermediate portion in the axial direction (when the outer diameter dimension is substantially constant in the axial direction), the outer diameter dimension of the stent is specified on the outer peripheral surface of the thick portion. At the same time, the reduced diameter portion is formed by the thick portion.
In the invention described in (vi) above, since the protrusions are provided on the outer peripheral surfaces of both ends in the axial direction of the stent, the protruding tip surface of the protrusions protrudes toward the outer periphery as compared with the intermediate portion in the axial direction. By applying the diameter reduction treatment to such a stent, both ends in the axial direction having the protrusions are reduced in diameter to the inner peripheral side until the protruding tip surface of the protrusion and the outer peripheral surface of the intermediate portion in the axial direction become flat. NS. As a result, when the stent is attached to the balloon, the outer diameter of the stent is defined by the protruding tip surface of the protrusion, and the inner diameters of both ends in the axial direction are reduced by the protruding dimension of the protrusion to reduce the diameter. It is composed.
In the invention described in the above (vii), since the outer protective tube is attached to both ends in the axial direction of the stent in addition to the inner protective tube, when the diameter is reduced by the crimp device, both ends in the axial direction of the stent are axial. The amount of diameter reduction is increased by the amount of the outer protective tube as compared with the middle portion in the direction. As a result, when the stent is attached to the balloon, both ends in the axial direction of the stent are made to bite into the balloon, and the stent can be effectively prevented from being displaced or dropped from the balloon.
In the invention described in the above (viii), since more connecting portions are formed at both ends in the axial direction of the stent than at the intermediate portions in the axial direction, the deformation rigidity of both ends in the axial direction of the stent is increased. NS. Therefore, when the diameter is uniformly reduced in the axial direction as in the conventional stent delivery catheter, the diameter of both ends in the axial direction is less likely to be reduced as compared with the intermediate portion in the axial direction. By attaching an outer protective tube to increase the amount of diameter reduction, the stent can be stably bitten into the balloon even at both ends in the axial direction with high deformation rigidity, effectively preventing the stent from shifting or falling off with respect to the balloon. obtain.
In the invention described in (ix) above, since the outer protective tube is attached with an axial length of at least one circumference in the skeletal structure of the stent, the axial length of the region to be reduced in diameter in the stent. Can be sufficiently secured to efficiently improve the fixation force of the stent to the balloon.

10, 70, 90: Stent delivery catheter, 14: Shaft, 16: Balloon, 18, 72, 92, 110: Stent, 44: Linear body, 48a, 48b, 112a: Connection part, 50: Crimp device, 56, 80, 102: reduced diameter part, 58: inner protective tube, 60: outer protective tube, 74: thick part, 76: outer peripheral surface of thick part, 94: outer peripheral surface of skeletal structure at both ends in the axial direction, 96: Protrusion, 98: Protruding tip surface

Claims (8)

A stent delivery catheter in which a stent having a skeletal structure that extends in the circumferential direction while folding back in the axial direction is extrapolated to a balloon provided at the tip of the shaft.
In axial end portion of the stent, with the reduced diameter portion of the inner diameter is smaller with the axial length of the annular body located axially opposite end portions that put on the skeletal structure is provided,
The skeletal structure of the stent is formed with a plurality of connecting portions that connect axially adjacent portions to each other, and at both axially end portions of the stent, the circumference of the stent is larger than that of the axially intermediate portion of the stent. A stent delivery catheter characterized in that the connection portion is provided with a small separation distance in the direction. The stent delivery catheter according to claim 1, wherein the skeletal structure of the stent is formed by a linear body that extends spirally in the circumferential direction as a whole while being folded back in the axial direction. The stent delivery catheter according to claim 2, wherein the inclination angle of the spiral of the spirally extending linear body with respect to the axial direction of the stent gradually increases as it approaches the axial end portion and approaches vertical. Thick portions having a large thickness dimension of the skeleton structure are provided at both ends in the axial direction of the stent, and the outer diameter dimension of the stent is defined by the outer peripheral surface of the thick portion to reduce the diameter. The stent delivery catheter according to any one of claims 1 to 3, wherein the part is composed of the stent delivery catheter. Protrusions are formed on the outer peripheral surface of the skeletal structure at both ends in the axial direction of the stent, and the reduced diameter portion is formed by defining the outer diameter dimension of the stent by the protruding tip surface of the protrusion. The stent delivery catheter according to any one of claims 1 to 3. When manufacturing a stent delivery catheter by extrapolating a stent having a skeletal structure extending in the circumferential direction while folding back in the axial direction to a balloon provided at the tip of the shaft.
An inner protective tube covering the entire length in the axial direction and an outer protective tube covering both ends in the axial direction of the stent from the outside of the inner protective tube are attached to the stent externally inserted into the balloon. From the outside of the inner protective tube and the outer protective tube, the stent is reduced in diameter with a crimp device to provide a contractile portion in which the inner diameter is reduced in the stent, and the stent is attached to the balloon to attach the stent to the inner protective tube. A method for manufacturing a stent delivery catheter, which comprises removing the outer protective tube to obtain the stent delivery catheter. The skeletal structure of the stent is formed with a plurality of connecting portions that connect axially adjacent portions to each other, and in the axially intermediate portion of the stent, the circumference of the stent is larger than that of both ends in the axial direction of the stent. The method for manufacturing a stent delivery catheter according to claim 6 , wherein the connecting portion is provided with a large separation distance in the direction. In axial end portion of the stent, the manufacture of the stent delivery catheter of claim 6 or 7 mounting the outer protective tube has an axial length of the annular body located axially opposite end portions that put on the skeletal structure Method.

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