JP2012024329A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter with a new structure, by which a balloon can be positioned in a circumferential direction with respect to body tubular tissue and inflated so as to be bent in a suitable direction conforming to the bending direction of the body tubular tissue.SOLUTION: In the balloon catheter 10, a balloon 30 is attached in an externally inserted state to the distal end side of a catheter body 12 and a supply/drain passage 28 for supplying/sucking pressure fluid to/from the balloon 30 from the proximal end of the catheter body 12 is formed. A bent part 34 bent in the longitudinal direction by supplying pressure fluid via the supply/drain passage 28 and inflated is provided to the balloon 30, contrast markers 36 are provided to both end parts in the longitudinal direction and a part where the bent part 34 is externally inserted, respectively, in the part where the balloon 30 is externally inserted in the catheter body 12, and contrast shapes of the contrast markers 36 are varied in the circumferential direction.

Description

  The present invention is a type of catheter that is used by being inserted into a tubular tissue such as a blood vessel, digestive organ, bronchial tube, etc., for observing the insertion site or performing medical treatment, and is expanded by supply / discharge of pressure fluid from the outside / Relates to a balloon catheter with a deflating balloon.

  Conventionally, a catheter has been used as a kind of medical instrument for inspecting or treating a body tubular tissue such as a blood vessel or a tubular organ. As one kind, a catheter is used to supply / discharge pressure fluid from the outside. Balloon catheters with inflated / deflated balloons are known. The balloon catheter is provided with a bag-like balloon on the distal end side of the catheter, and the balloon is inflated by sending pressure fluid into the balloon from the proximal end side of the catheter.

  This balloon catheter can be used, for example, to insert a stenotic blood vessel and inflate the balloon in the blood vessel to expand the stenotic site, or to inflate the balloon in the blood vessel and attach a drug adhered to the surface of the blood vessel treatment. Used for treatment applied to the site. In addition, inflating a balloon with a cutting blade on the surface at the site of stenosis of the blood vessel to remove the thrombus, etc. is being studied, and when placing the stent in the blood vessel, the balloon is inflated in the stent and the stent is It is also used to press against blood vessels by spreading.

  By the way, a treatment site in a blood vessel or the like may be curved as well as linear. In order to perform treatment using a balloon catheter as described above on a curved treatment site, a balloon that is inflated into a curved shape as shown in, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2003-320031) has also been proposed. ing. This balloon seems to have been developed mainly for peripheral bent lesions, but it is hoped that a bent balloon will be developed to deform the stent into a curved shape and braze it into a shape corresponding to the curved shape of the blood vessel. It is rare.

  However, since treatment with a catheter is not performed by directly observing the treatment site, it is difficult to determine the balloon before deployment in a specific direction in the circumferential direction of the catheter body. Therefore, conventionally, when the balloon bending direction is different from the blood vessel bending direction, the balloon receives a reaction force from the blood vessel based on the uneven contact pressure exerted on the blood vessel, and in the normal direction. It was only operated in the hope that it would rotate automatically. However, depending on the state of the blood vessel or balloon, there is a possibility that the balloon does not rotate smoothly in the blood vessel, and when the bending direction of the balloon and blood vessel is reversed, there is almost no uneven distribution of contact pressure. It is also conceivable that the balloon does not rotate. For these reasons, a curved balloon may swell in a curved state in a direction different from the curved direction of the blood vessel.

JP 2003-320031 A

  The present invention has been made in the background of the above-described circumstances, and the problem to be solved is to match the balloon in an appropriate direction with respect to the body tubular tissue, and to make an appropriate direction in accordance with the bending direction of the body tubular tissue. It is an object of the present invention to provide a balloon catheter having a novel structure that can be inflated so as to be bent.

  According to a first aspect of the present invention, a balloon is attached to the distal end side of a catheter main body formed with a guide wire lumen through which the guide wire is inserted in an extrapolated state, and the guide wire In a balloon catheter in which a supply / exhaust passage for supplying and sucking pressure fluid to and from the balloon is formed from the proximal end side of the lumen for use in the balloon, the balloon is elongated by the supply of the pressure fluid through the supply / exhaust passage. A curved portion that is curved and swells in the vertical direction is provided, and the portion of the catheter body where the balloon is extrapolated is contrasted with both ends in the length direction and the portion where the curved portion is extrapolated. A marker is provided, and the contrast shape of the contrast marker changes in the circumferential direction.

  According to the 1st aspect, the contrast marker is mounted | worn with the length direction both ends of the part in which the balloon was extrapolated in the catheter main body. Therefore, by confirming the contrast markers at both ends by X-ray fluoroscopy and the like, the positions of both ends of the balloon can be grasped, and whether or not the balloon is inserted into a site to be treated such as a stenosis site of a blood vessel. Can be easily determined.

  In addition to the both end portions of the catheter body, contrast markers are attached to portions corresponding to the curved portions. Therefore, when the balloon is inflated into a curved shape, the curved direction of the balloon can be easily specified by confirming the arrangement of the contrast markers. That is, when the balloon bending direction is on the near side or the back side with respect to the fluoroscopic direction, the contrast markers at both ends and the contrast markers at the curved portion are aligned on the same straight line. On the other hand, when the balloon bending direction is other than the front side or the back side as described above, the contrast markers at both end portions and the contrast marker at the curved portion are arranged on a curve along the curve direction of the balloon. Therefore, by seeing through the array of the contrast markers, the curve direction of the balloon can be quickly identified, and by rotating the balloon so as to match the curve direction of the inserted tube (blood vessel, etc.) The balloon can be inflated into a curved shape along the tubular organ.

  In addition, since the contrast shape of the contrast marker itself changes in the circumferential direction, the curvature direction of the balloon can be determined even in a folded state by confirming the contrast shape of the contrast marker. As a result, the balloon can be inflated after being positioned so as to bend in a direction along the body tubular tissue such as a blood vessel in advance, and the blood vessel is prevented from being strongly pressed locally by the inflated balloon. Can do.

  As described above, since the balloon bending direction can be discriminated by fluoroscopy, it is possible to avoid damage to blood vessels and the like due to local contact of the balloon, and a wide range of the surface of the balloon can be avoided. The target treatment (application of a drug, expansion of a stenotic site in a blood vessel, etc.) can be effectively performed by stably pressing the blood vessel or the like.

  According to a second aspect of the present invention, in the balloon catheter according to the first aspect, the contrast marker is fitted on the outer peripheral surface of the catheter body.

  According to the second aspect, the contrast marker can be easily attached to the catheter body. The contrast marker may have a cylindrical shape or a C-shaped cross section, and may be extrapolated or wound around the catheter body to be caulked, bonded, welded, etc. It may be fixed with.

  According to a third aspect of the present invention, in the balloon catheter according to the first or second aspect, the dimension in the length direction of the contrast marker is different between the outer peripheral side and the inner peripheral side of the curved portion of the balloon. It is what.

  According to the third aspect, the contrast direction of the contrast marker is changed in the circumferential direction and the balloon bending direction is determined by a simple structure in which the outer circumference side and the inner circumference side of the contrast marker are made different in length direction. Can be possible.

  According to a fourth aspect of the present invention, in the balloon catheter according to the third aspect, the lengthwise end surface of the contrast marker is an inclined surface inclined with respect to the central axis of the catheter body. The dimension in the length direction of the contrast marker is different between the outer peripheral side and the inner peripheral side of the curved portion.

  On the other hand, according to a fifth aspect of the present invention, in the balloon catheter according to the third aspect, a step is provided on the circumference of the end surface in the length direction of the contrast marker, whereby the length of the contrast marker in the length direction is increased. The dimensions are different from each other on the outer peripheral side and the inner peripheral side.

  According to the fourth and fifth aspects, it is possible to form contrast markers having different lengths in the longitudinal direction on the outer peripheral side and the inner peripheral side of the curved portion of the balloon with a specific and simple structure. In addition, the inclined surface and level | step difference in a 4th, 5th aspect may be formed only in one edge part of the length direction of a contrast marker, and may be formed in the both ends of a length direction. .

  According to a sixth aspect of the present invention, in the balloon catheter according to any one of the first to fifth aspects, the contrast shape of the contrast marker is such that the curved portion is curved toward the front side with respect to the fluoroscopic direction. The case differs from the case where the case is curved to the back side.

  According to the sixth aspect, it is possible to discriminate the curvature toward the front side and the curvature toward the back side, which are difficult to discriminate only by the arrangement of the contrast marker, based on the contrast shape of the contrast marker. Thereby, even when the balloon is curved in any direction in the circumferential direction, the curved direction can be specified by combining the array of contrast markers and the contrast shape.

  In this aspect, it is possible to set the contrast markers that can be discriminated in different directions from each other, preferably for the contrast markers that are mounted at a plurality of locations in the length direction of the catheter body. For example, as shown in a second embodiment to be described later, when contrast markers are attached at three locations, ie, both end portions and a central portion in the length direction of the catheter body, the balloon is laterally moved by contrast markers at both end portions. It is possible to discriminate between the inner circumference side and the outer circumference side when contrasting from the front, while distinguishing between the front (inner circumference) side and the rear (outer circumference) side when the balloon is contrasted from the front or the back by the contrast marker in the center part. Also good.

  A seventh aspect of the present invention is the balloon catheter according to any one of the first to sixth aspects, wherein the contrast marker includes both end portions in the length direction of the extrapolated portion of the balloon in the catheter body. A cylindrical body that is attached to each of the central portions and that has at least one end surface in the axial direction as an inclined end surface that is cut obliquely with respect to the central axis, and is used as the contrast marker; and The inclined end surface of the contrast marker attached to the central portion is directed in a direction different by 90 degrees around the central axis with respect to the inclined end surface of the contrast marker attached to the both end portions.

  According to this aspect, it becomes possible to more easily confirm the position and the bending direction of the balloon based on the contrast image of the contrast marker. In particular, the curved direction of the balloon can be more accurately recognized by the relative difference between the contrast images of the contrast markers provided at the center and both ends in the length direction of the balloon. In addition, as the contrast marker of this aspect, for example, as shown in a second embodiment to be described later, a cylindrical body having both sides in the axial direction as inclined end surfaces and a substantially isosceles trapezoidal shape when viewed from the side is adopted. I can do it. More preferably, as shown in a third embodiment to be described later, one of the axial directions is an inclined end surface and the other axial direction is a cut end surface in a direction perpendicular to the axis, and the side view is substantially unequal in the shape of a trapezoid. A cylindrical body is adopted.

  According to an eighth aspect of the present invention, there is provided the balloon catheter according to any one of the first to seventh aspects, wherein the stent is inserted into a tubular organ in the body and used to deform into a curved shape. For stent deformation.

  According to the eighth aspect, a linear tubular stent placed in a tubular organ such as a blood vessel is brazed in accordance with the original curved shape of the tubular organ, so that the stent is applied to the tubular organ. The contact pressure can be prevented from acting locally. Therefore, damage to blood vessels and the like due to contact of the stent can be avoided, and safety can be ensured.

  In addition, by positioning and inflating the curved balloon in the circumferential direction with respect to the tubular organ, the stent can be deformed into a desired shape, and the contact pressure of the stent with respect to the tubular organ is expanded when the balloon is expanded. Ascending can be suppressed, and the burden on the tubular organ and thus the patient can be reduced.

  According to the present invention, in a balloon catheter provided with a curved balloon, it is possible to discriminate the bending direction of the balloon through fluoroscopy, so that when the balloon is used for a curved portion in a tubular organ such as a blood vessel, the balloon is a blood vessel. It is possible to avoid bulging and bending in a direction different from the bending direction. As a result, it is possible to prevent an excessive pressing force from acting on the blood vessel and the like, thereby reducing the burden on the patient and effectively and reliably performing the intended treatment.

1 is an overall schematic diagram showing a balloon catheter as a first embodiment of the present invention. It is the front-end | tip part longitudinal cross-sectional view of the catheter shown by FIG. 1, Comprising: II-II sectional drawing in FIG. III-III sectional drawing in FIG. FIGS. 2A and 2B are side views of the distal end portion of the catheter shown in FIG. 1, in which FIG. 1A shows a state before the balloon is deployed, and FIG. The perspective view of the contrast marker used for the catheter shown by FIG. The figure which expands and shows the principal part of the balloon catheter as the 2nd Embodiment of this invention. Explanatory drawing which shows in model the principal part structure of the balloon catheter as the 3rd Embodiment of this invention. The perspective view of the contrast marker used for the balloon catheter as the 4th Embodiment of this invention. FIG. 11 is a longitudinal sectional view of a distal end portion of a balloon catheter as a fifth embodiment of the present invention, and is a IX-IX sectional view of FIG. 10. XX sectional drawing in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, FIG. 1 shows a balloon catheter 10 as a first embodiment of the present invention. The balloon catheter 10 includes a long catheter body 12, and a hub 14 that also serves as a gripping portion is provided on the proximal end (proximal end) side of the catheter body 12. Then, the distal end (distal end) side of the catheter body 12 is inserted into the blood vessel from the wrist or thigh of the human body and reaches the treatment site such as the coronary artery, and the operation on the hub 14 side exposed from the human body is performed. A treatment such as disposition of the stent 38 to a stenosis site, which will be described later, is performed.

  More specifically, the catheter body 12 has a thickness that can be inserted into a blood vessel to be inserted and a length that reaches a target treatment site. In addition, it is made of a soft material that can be bent along the blood vessel. For example, polyamide, polyvinyl chloride, polyurethane, polyimide, polyethylene, polyethylene elastomer, polypropylene, polytetrafluoroethylene, polyetheretherketone, polyvinylidene fluoride, etc. A material formed of a synthetic resin material, a metal material such as stainless steel, a nickel-titanium alloy, or a combination thereof is suitably employed.

  The catheter body 12 is formed by an inner shaft 16 and an outer shaft 17 each having a long tube shape, and a distal shaft 18, a port shaft 19, and a main shaft in which the outer shaft 17 is formed in series with each other. 21. Further, the inner shaft 16 is inserted through the central hole of the distal shaft 18, and the distal end of the inner shaft 16 protrudes from the distal end of the distal shaft 18 in the axial direction. Furthermore, a tip end 20 having a substantially cylindrical shape that is reduced in diameter toward the distal end side is attached in series to the distal end side of the inner shaft 16. The outer shaft 17 includes a main shaft 21, a port shaft 19, and a distal shaft 18 in order from the proximal end side. An annular or cylindrical strain relief 23 is extrapolated at the proximal end of the main shaft 21 to prevent deformation (bending) at the proximal end of the main shaft 21.

  2 to 4, a guide wire lumen 22 extending in the length direction is formed inside the inner shaft 16. The guide wire lumen 22 is continuously formed with a substantially constant cross-sectional shape from the proximal end to the distal end of the inner shaft 16. The guide wire lumen 22 opens to the distal end of the inner shaft 16, and communicates with the outside through a port 24 formed at the distal end of the port shaft 19 on the proximal end side of the inner shaft 16. Has been.

  A guide wire 26 is inserted into the guide wire lumen 22 so that it can be inserted and removed. In short, the guide wire 26 is inserted into the inner shaft 16, the distal end thereof protrudes from the distal end of the inner shaft 16, and the proximal end is taken out from the port 24 of the port shaft 19. .

  The guide wire 26 has a diameter smaller than the inner diameter of the inner shaft 16 and is inserted into the blood vessel in advance prior to insertion of the catheter body 12 including the inner shaft 16. Thereafter, the end portion of the guide wire 26 protruding outside the body is inserted into the distal end portion of the catheter body 12, and the distal shaft 18 constituting the distal end of the catheter body 12 is inserted into the blood vessel along the guide wire 26. As a result, the distal end of the catheter body 12 is smoothly inserted to the vicinity of the target treatment site. An annular depth marker 27 is extrapolated and fixed to the main shaft 21 so that the insertion amounts of the distal shaft 18 and the port shaft 19 into the body can be easily grasped visually.

  A pressure adjusting lumen 28 is formed between the inner shaft 16 and the distal shaft 18 in the radial direction. That is, the outer diameter of the inner shaft 16 is made smaller than the inner diameter of the distal shaft 18, and an annular gap is formed between them. A pressure adjusting lumen 28 is formed using the gap. The pressure adjusting lumen 28 has a proximal end connected to a pressure fluid supply / discharge device (not shown) through a central hole of the port shaft 19 and a central hole of the main shaft 21. In short, the supply / discharge path in the present embodiment is formed using the pressure adjusting lumen 28, the center hole of the port shaft 19 and the main shaft 21.

  A balloon 30 is attached to the distal end side of the catheter body 12. The balloon 30 has a substantially cylindrical bag shape formed of a thin film, and is disposed so as to surround the distal end portion of the inner shaft 16 protruding from the distal shaft 18, and is made of polyamide, polyethylene, polyethylene elastomer, polyurethane. For example, a soft synthetic resin having flexibility, a rubber film, or the like is used.

  Further, the proximal end of the balloon 30 is fixed to the distal end of the distal shaft 18 by welding or the like, and the inner space of the balloon 30 is communicated with the pressure adjusting lumen 28, while the distal end of the balloon 30 is It is welded to each outer peripheral surface of the distal end of the inner shaft 16 and the proximal end of the tip tip 20. Then, the pressure fluid is supplied / discharged from / to the inner space of the balloon 30 through the pressure adjusting lumen 28 from the proximal end side of the catheter body 12 by a pressure fluid supply / discharge device (not shown) connected to the hub 14. It has become. Thereby, the pressure in the balloon 30 is adjusted, and the expansion and contraction of the balloon 30 are controlled. Note that as the pressure fluid supplied to the balloon 30, not only a liquid such as a contrast agent or physiological saline mainly composed of barium sulfate or iodine, but also a gas such as air, carbon dioxide, oxygen, or the like can be used.

  Further, as shown in FIG. 4B, the balloon 30 has a curved portion 34 that extends over substantially the entire length direction, and bulges in a curved shape as a whole by supplying pressure fluid. This is a so-called banana balloon. As shown in FIG. 4A, the bending portion 34 is folded into a linear shape in a contracted state before the pressure fluid is fed, and is pressurized by feeding the pressure fluid. However, it may be preliminarily formed in a curved shape in the contracted state.

  Since the balloon 30 is curved in this way, when the balloon catheter 10 is inserted into the blood vessel and the balloon 30 is inflated in the blood vessel, the balloon 30 can be disposed so as to bend along the blood vessel bending direction. Thus, the contact pressure due to the expansion of the balloon 30 can be prevented from acting locally on the blood vessel. Therefore, safe and effective treatment can be realized while suppressing damage and deformation of blood vessels.

  A plurality of contrast markers 36 are fitted on the inner shaft 16. As shown in FIG. 5, the contrast marker 36 is a substantially cylindrical metal fitting having an inner diameter corresponding to the outer diameter of the inner shaft 16, and is made of an X-ray opaque material such as an alloy of platinum and iridium. Made of metal.

  The contrast marker 36 is attached to an extrapolated portion of the balloon 30 in the inner shaft 16. More specifically, a contrast marker 36 a is attached to a portion of the inner shaft 16 that protrudes from the distal shaft 18 at a position near the proximal end of the balloon 30, and the distal end of the balloon 30 on the inner shaft 16. A contrast marker 36b is attached at a position close to. Furthermore, a contrast marker 36 c is attached to the center of the curved portion 34 in the length direction of the balloon 30. Then, the positions of the contrast markers 36a, 36b, and 36c were confirmed by X-ray fluoroscopy (transmission using an X-ray television system for displaying and confirming X-ray transmission images on a monitor or the like) to be in a contracted state. The position of the balloon 30 in the blood vessel can be grasped. The contrast marker 36 is attached to the inner shaft 16 which is a portion of the catheter body 12 inserted into the balloon 30, in other words, a portion of the catheter body 12 where the balloon 30 is extrapolated. It is arranged on the circumference side.

  Further, the contrast marker 36 has a tapered shape in which both axial end surfaces are inclined toward the central side in the axial direction toward one radial direction, whereby the axial dimension changes in the circumferential direction. As a result, the shape of contrast in the radial direction changes in the circumferential direction, and a direction (perpendicular to the plane of the paper in FIG. 1) that is substantially orthogonal to the bending direction of the balloon 30 (vertical direction in FIG. 1). It is assumed that the contrast shape at the top is an isosceles trapezoid.

  The contrast marker 36 is mounted so that the side with the smaller axial dimension is on the inner side of the balloon 30 in the bending direction, and the contrast shape of the contrast marker 36 in the direction perpendicular to the bending direction of the balloon 30 is confirmed. Thus, the bending direction of the balloon 30 can be determined in the contracted state. That is, in the contrast shape of the contrast marker 36 in the direction orthogonal to the curve direction of the balloon 30, the side with the smaller axial dimension is the inside of the balloon 30 in the curve direction.

  In the balloon catheter 10 structured according to this embodiment, three contrast markers 36 a, 36 b, and 36 c are attached to the catheter body 12. Thereby, the bending direction of the balloon 30 can be specified by confirming the arrangement of the three contrast markers 36a, 36b, and 36c. That is, the contrast marker 36c attached in the middle in the length direction is confirmed at a position shifted to the outer peripheral side with respect to the straight line connecting the contrast marker 36a and the contrast marker 36b attached at both ends in the length direction. From the above, the bending direction of the balloon 30 can be specified. Therefore, even when the contrast shape of the contrast marker 36 is difficult to discriminate, it is possible to quickly specify the bending direction when the balloon 30 is inflated.

  Further, the positioning of the balloon 30 in the circumferential direction is also realized by adopting a cylindrical contrast marker 36 whose both axial end surfaces are tapered and confirming the contrast shape of the contrast marker 36 by X-ray fluoroscopy. Is done. According to this, since the orientation in the circumferential direction of the balloon 30 is specified before the balloon 30 is deployed, the balloon 30 can be positioned in advance along the blood vessel bending direction.

  Further, the contrast marker 36 has a substantially cylindrical shape, and the circumferential direction is specified based on the contrast shape by changing the axial length in the circumferential direction. Thus, in this embodiment, the positioning of the balloon 30 in the circumferential direction can be realized using the contrast marker 36 having a very simple structure. Further, the contrast marker 36 is extrapolated to the catheter main body 12 and is fixedly fitted, so that the contrast marker 36 can be easily attached to any part of the catheter main body 12.

  By the way, the balloon catheter 10 having such a contrast marker 36 is used, for example, for deforming a stent 38 having high bending rigidity and low blood vessel shape compatibility into a curved shape corresponding to a blood vessel. The stent 38 has a mesh tube shape made of a metal such as stainless steel, tantalum, cobalt alloy, nickel-titanium alloy, and is formed by braiding a wire material or laser cutting the tube body into a mesh shape. Is done. The stent 38 is a balloon expandable type, and is inserted into a stenosis portion of a blood vessel after being externally inserted into a balloon catheter having a linear balloon, and then expanded in diameter by expansion of the balloon, thereby narrowing the blood vessel. The part is pushed and held in an expanded state. Furthermore, as for the aspect of the stent 38, a drug eluting stent, a bare metal stent (no drug), etc. are mentioned, for example. If the stent 38 is a drug eluting stent, the drug is applied to the surface of the metal, and an effect of suppressing the restenosis of the blood vessel can be expected. In FIG. 4B, the stent 38 is indicated by a two-dot chain line, and a cross section of a blood vessel (39) as a tubular organ is indicated by a one-dot chain line.

  With such a straight stent 38 placed in the blood vessel, the balloon catheter 10 is inserted into the inner peripheral side of the stent 38. Then, the pressure fluid is fed into the balloon 30 through the pressure adjusting lumen 28 and the balloon 30 expands in an arc shape, whereby the stent 38 is pressed by the balloon 30 and shaped into a curved shape along the balloon 30.

  Since the balloon 30 is preliminarily swelled into a curved shape corresponding to the narrowed portion of the blood vessel, the deformation of the blood vessel due to the rigidity of the stent 38 is eliminated, and the blood vessel is held in the initial curved shape. In this state, the diameter of the narrowed portion of the blood vessel is increased.

  As described above, by adopting the balloon catheter 10 structured according to the present embodiment for deforming the stent 38, the curved portion of the blood vessel is stretched into a linear shape different from the original by the stent 38 formed of metal. It is possible to prevent the blood vessel from being damaged by an unnecessary external force.

  In the balloon catheter 10, the circumferential direction can be confirmed by the contrast shape of the contrast marker 36 when the stent 38 is inserted into the inner periphery. Thereby, the balloon 30 is positioned in the circumferential direction and inflated into a curved shape so as to correspond to the curved shape of the blood vessel. Therefore, the stent 38 is deformed into an appropriate curved shape along the curved direction of the blood vessel, and it is possible to avoid the stent 38 being pressed against the blood vessel more strongly than necessary during the expansion process of the balloon 30.

  Further, as shown in the first embodiment, the contrast marker 36 may be mounted so that the lengths are different from each other on the inner peripheral side and the outer peripheral side of the balloon 30. FIG. As shown in the second embodiment of the present invention, the lengths on both sides in the direction perpendicular to the paper surface of FIG. 6 may be different from each other. According to this, when the bending direction of the balloon 30 is the front side or the back side with respect to the fluoroscopic direction, the contrast marker 36 has a case where it is curved toward the front side and a case where the balloon 30 is curved toward the back side. Since the contrast shape is different, the bending direction of the balloon 30 can be specified. Therefore, even if the balloon 30 is inserted into the blood vessel in any direction, the curvature of the balloon 30 depends on the arrangement of the three contrast markers 36a, 36b, 36c and the contrast shape of the contrast markers 36a, 36b, 36c. The direction can be grasped by X-ray fluoroscopy. FIG. 6 shows an enlarged view of the main part of the balloon catheter having the structure according to the second embodiment. Moreover, about the site | part and member substantially the same as the said 1st Embodiment, description is abbreviate | omitted by attaching | subjecting the same code | symbol in a figure. In FIG. 6, the balloon 30 is curved downward in FIG. 6 as it goes to the protruding tip side (right side in FIG. 6).

  Further, among the three contrast markers 36a, 36b, and 36c, for example, the contrast marker 36a and the contrast marker 36b are mounted in the direction of the first embodiment, and the contrast marker 36c is mounted in the mounting direction of the first embodiment. It is also possible to mount in a direction rotated 90 ° from the angle. According to this, in the case of bending in a direction other than the front side or the back side with respect to the fluoroscopic direction, the bending direction can be specified in advance by the contrast shape of the contrast markers 36a and 36b. On the other hand, in the case of bending toward the near side or the far side with respect to the fluoroscopic direction, the bending direction can be specified in advance by the contrast shape of the contrast marker 36c.

  Further, when three contrast markers are employed in this way, for example, a balloon catheter as the third embodiment whose main part schematic structure is shown in FIG. 7 can be more suitably configured. FIG. 7 shows a state in which the inner shaft 16 is rotated by 90 degrees around the central axis from the [initial position] as a reference, and a “visual” view showing an appearance at each rotational position. And the figure of “contrast” seen through X-ray.

  That is, in this balloon catheter, a total of three contrast markers 36d, 36e, and 36f are extrapolated in the vicinity of both ends in the length direction and the central portion with respect to the mounting position of the balloon (not shown) on the inner shaft 16. It is fitted and fixed. Each of the contrast markers 36d, 36e, and 36f has a shape in which one end of a hollow cylindrical body is cut in a direction perpendicular to the axis and the other end is cut in an oblique direction. Further, the contrast marker 36f mounted at the center in the length direction of the inner shaft 16 is relatively rotated 90 degrees in the circumferential direction with respect to the contrast markers 36d and 36e mounted on both sides in the length direction of the inner shaft 16. In short, the contrast markers 36d and 36e are mounted with their oblique cut end faces on the same side in the length direction and inclined in the same direction, while the central contrast marker 36f has a long oblique cut end face. Although it is located on the same side in the vertical direction, it is mounted while being inclined in a direction different from the other contrast markers 36d and 36e (inclined in a direction different by 90 degrees around the central axis).

  By mounting such three contrast markers 36d, 36e, and 36f, the circumferential position of the inner shaft 16, and thus the bending direction of the balloon, can be confirmed by contrast images with X-rays. In particular, in the present embodiment, the use of the axially asymmetric contrast markers 36d, 36e, and 36f that are obliquely cut at only one end makes the left and right contrast markers 36d and 36e at [initial position] in FIG. The contrast image from the side becomes an unequal leg trapezoid, which makes visual confirmation easier.

  Next, FIG. 8 shows a contrast marker 40 used in a balloon catheter as a fourth embodiment of the present invention. The contrast marker 40 is formed of the same X-ray impermeable material as the contrast marker 40 of the first embodiment, and has a substantially cylindrical shape as a whole.

  The contrast marker 40 has a substantially circular cross section (substantially cylindrical shape) on one side in the axial direction, and a substantially semicircular cross section (substantially semicylindrical shape) on the other side in the axial direction. That is, the contrast marker 40 of the present embodiment has a shape having a notch 41 in which approximately 1/4 of the whole is cut out from a cylindrical shape. In other words, the contrast marker 40 is provided with steps 42, 42 at portions located on the diameter line on the circumference in a portion from one end face to the approximate center in the length direction. One half of the circumference is cut off.

  As a result, the contrast marker 40 is set in two stages having different lengthwise dimensions by half a circle, and the contrast shapes on both sides in one radial direction are substantially the same rectangles, and the radial direction is in one direction. The contrast shapes on both sides in the orthogonal radial direction are different from each other in line symmetry.

  The contrast marker 40 having such a structure is externally fitted to the inner shaft 16 as in the first embodiment. At that time, the contrast marker 40 is mounted so that the notch 41 of the contrast marker 40 is positioned on the inner peripheral side in the bending direction of the bending portion 34 of the balloon 30. In short, the contrast marker 40 has a portion with a large axial dimension positioned on the outer peripheral side of the curved portion 34 of the balloon 30 and a portion with a small axial dimension positioned on the inner peripheral side of the curved portion 34 of the balloon 30. It is attached.

  Thereby, the balloon 30 is positioned in the circumferential direction so that the notch 41 is positioned on the inner circumferential side of the blood vessel in the bending direction, and inserted into the lumen of the stent 38, so that the balloon 30 is bent along the blood vessel. The stent 38 can be inflated, and the stent 38 is deformed into a curved shape corresponding to the placement site in the blood vessel.

  As described above, the contrast marker capable of positioning the balloon 30 in the circumferential direction with respect to the blood vessel only needs to be able to specify the direction of the contrast marker from the projected shape perpendicular to the axis. Any structure that can be positioned by a recess, a protrusion, or the like can be employed.

  The principal part of the balloon catheter 50 as the 5th Embodiment of this invention is shown by FIG. The balloon catheter 50 includes a catheter body 52 as a shaft.

  The catheter body 52 is formed of a flexible material similar to the inner catheter body 52 of the first embodiment, and has a small-diameter longitudinal tube structure. A plurality of contrast markers 36 are fitted on the distal end side of the catheter body 52, and the balloon 30 is disposed so as to surround the outer peripheral side. Both end portions in the length direction of the balloon 30 are fixed to the outer peripheral surface of the catheter main body 52, and a pressure fluid introduction region is provided between the outer peripheral surface of the catheter main body 52 and the inner peripheral surface of the balloon 30. Is formed.

  Further, a guide wire lumen 54 extending in the length direction and a pressure adjusting lumen 56 as a supply / exhaust path are formed inside the catheter body 52. The guide wire lumen 54 penetrates the catheter body 52 in the length direction with a substantially constant elliptical cross section. The guide wire 26 is inserted through the guide wire lumen 54.

  The pressure adjusting lumen 56 is provided in parallel with the guide wire lumen 54 and has a length that does not reach the distal end surface of the catheter body 52. In addition, a communication hole 58 extending in the radial direction is formed at the distal end of the pressure adjusting lumen 56, and the pressure adjusting lumen 56 is communicated with the inside of the balloon 30. As a result, the pressure fluid is supplied / discharged from the proximal end side of the catheter main body 52 through the pressure adjusting lumen 56 into the balloon 30 so that the balloon 30 is inflated / deflated.

  Thus, the catheter body does not necessarily have a double cylinder structure, and may be constituted by the catheter body 52 having the guide wire lumen 54 and the pressure adjusting lumen 56 in parallel. It is also possible to adopt a triple-lumen structure catheter body in which a dosing lumen extending in parallel with and independently of any of the guide wire lumen 54 and the pressure adjusting lumen 56 is formed.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the contrast marker may be attached to four or more locations including the proximal end, the distal end, and the center of the curved portion of the balloon in the catheter body. Thus, by attaching more contrast markers, it becomes possible to grasp the curved shapes of the balloon and the catheter body in more detail.

  In addition, the shape of the contrast marker shown in each of the embodiments is not particularly limited. For example, a partial protrusion protruding on the outer peripheral surface may be provided, or a hole penetrating in the radial direction may be provided. It may be provided. Further, the contrast marker is not limited to a cylindrical shape, and may be, for example, a linear shape or a tip shape and embedded in the catheter body. In that case, in addition to embedding contrast markers with different shapes on the inner and outer peripheral sides, the contrast shapes on the inner and outer periphery sides are made different by arranging a plurality of contrast markers with the same shape at different pitches. You can also.

  Furthermore, the contrast marker does not necessarily have to be solid. For example, the contrast marker may be formed by applying or enclosing a liquid or gel contrast agent to the catheter body.

  In addition, the balloon is not necessarily limited to the one that is partially curved in the middle portion in the length direction, but the one that is curved over the entire length in the length direction or the curvature changes on the arc. Also includes those that are. Moreover, when it is partially curved at a plurality of locations, the curved portions at the plurality of locations may be curved in different directions or may be curved with different curvatures.

  In the above embodiment, the rapid exchange type (RX type) catheter to which the present invention is applied has been described, but the present invention can also be applied to an over-the-wire type (OTW type) catheter.

10: Balloon catheter, 12, 52: Catheter body, 16: Inner shaft, 22, 54: Lumen for guide wire, 28, 56: Lumen for pressure adjustment (supply / discharge path), 30: Balloon, 34: Curved portion, 36, 40: contrast marker, 38: stent

Claims (8)

A balloon is attached to the distal end side of the catheter body formed with a guide wire lumen through which the guide wire is inserted, and is inserted from the proximal end side of the guide wire lumen. In a balloon catheter in which a supply / exhaust passage for supplying and sucking pressure fluid to and from a balloon is formed,
The balloon is provided with a curved portion that is curved and expands in the length direction by the supply of the pressure fluid through the supply / discharge passage, and the portion of the catheter body where the balloon is extrapolated has a length. A balloon catheter, characterized in that a contrast marker is provided at each of both ends of the direction and a portion where the curved portion is extrapolated, and the contrast shape of the contrast marker changes in the circumferential direction.   The balloon catheter according to claim 1, wherein the contrast marker is fitted on the outer peripheral surface of the catheter body.   The balloon catheter according to claim 1 or 2, wherein a dimension in a length direction of the contrast marker is different between an outer peripheral side and an inner peripheral side of the curved portion of the balloon.   The lengthwise end surface of the contrast marker is an inclined surface inclined with respect to the central axis of the catheter body, so that the lengthwise dimension of the contrast marker is on the outer peripheral side and inner peripheral side of the curved portion. The balloon catheter according to claim 3, which is different from each other.   The balloon catheter according to claim 3, wherein a step is provided on the circumference of the end surface in the length direction of the contrast marker, so that the dimension in the length direction of the contrast marker is different between the outer peripheral side and the inner peripheral side.   The contrast shape of the contrast marker is different between the case where the curved portion is curved toward the front side and the case where the curved portion is curved toward the back side, according to any one of claims 1 to 5. The balloon catheter described. The contrast marker is attached to both end portions and a central portion in the length direction of the extrapolated portion of the balloon in the catheter body,
As the contrast marker, a cylindrical body having an inclined end surface in which at least one end surface in the axial direction is cut obliquely with respect to the central axis is used, and the tilt of the contrast marker mounted on the central portion is used. The balloon catheter according to any one of claims 1 to 6, wherein an end face is directed in a direction different by 90 degrees around a central axis with respect to the inclined end face of the contrast marker attached to both end portions.   The balloon catheter according to any one of claims 1 to 7, wherein the balloon catheter is used for deforming a stent inserted into a tubular organ in a body and deformed into a curved shape.

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