JP4435903B2 - Medical balloon catheter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an improvement of a medical balloon catheter used in percutaneous angioplasty (PTA, PTCA) for expanding and treating stenotic or occluded portions of vascular lumens such as coronary arteries, limb arteries, renal arteries and peripheral blood vessels. It is about.
[0002]
[Prior art]
A conventional balloon catheter will be described with reference to FIG. FIG. 9 is an overall side view showing a cross section of a main part of a general over-the-wire balloon catheter. The conventional balloon catheter 60 includes a catheter shaft 61, a balloon (expansion body) 62 joined to the distal end of the catheter shaft 61, and a manifold 63 connected to the proximal end of the catheter shaft 61. . In the illustrated example, the vicinity of the tip including the balloon 62 is enlarged and displayed for the sake of easy explanation.
[0003]
The catheter shaft 61 is disposed in an outer tube (outer tube) 65 constituting an inflation lumen 64 through which a pressure fluid such as a contrast medium or physiological saline supplied to the balloon 62 is passed, and an inner lumen of the outer tube 65. The manifold 63 located at the base end is provided with a port communicating with the inflation lumen 64 and the guide wire lumen 67 through which the guide wire passes. Thus, the balloon catheter having the double tube structure of the outer tube (outer tube) 65 and the inner tube (guide wire passage tube) 66 is also called a co-axial type. . The balloon 62 has a tube shape, has tapered portions 69A and 69B that gradually decrease in diameter at both ends of the straight tube portion 68, and sleeves 70A and 70B at both ends of the tapered portions 69A and 69B. Configured. The proximal sleeve portion 70A is externally joined to the end portion of the outer tube 65, and the distal sleeve portion 70B is joined to the vicinity of the distal end of the guide wire passing tube 66 that penetrates the balloon 62. . The outer tube 65 is often used by connecting a plurality of different tube materials on the proximal side and the distal side in order to improve the pushing force transmission.
[0004]
An operation example of PTCA (Percutaneous Transluminal Coronary Angioplasty) using such a balloon catheter 60 is as follows. First, a guide wire (not shown) is inserted into the guide wire lumen 67, and the distal end of the guide wire is passed through the aorta of the patient in advance to the lesion site of the stenosis or occlusion in the coronary artery. Next, the manifold 63 is operated, and the balloon 62 is inserted along the guide wire so as to coincide with the lesion site. Then, pressure fluid is applied to the balloon 62 through the inflation lumen 64 by a syringe or the like, and the balloon 62 is inflated. , Extended treatment of the lesion site. Thereafter, the balloon 62 is deflated and contracted, folded, and removed from the body to complete PTCA. As the guide wire, as described in Japanese Patent Publication No. 4-5467 and Japanese Patent Publication No. 4-25024, there is a guide wire whose tip is made of a metal spring and whose backbone is made of a metal wire.
[0005]
In recent PTA and PTCA, it is required to expand a lesion site having a high degree of flexion or stenosis, for example, a calcified lesion site having a very hard blood vessel wall, and a stent (an endometrial detachment or the like has occurred) In order to ensure blood flow as an emergency treatment, or to prevent the occurrence of stenosis again, a metal mesh or coil placed after the stenosis is expanded may be guided to the lesion site to be expanded. Has been done. At this time, dilation treatment of the lesion site is not limited to one time, and usually requires several dilation treatments. If the balloon is removed from the body after dilatation treatment and it is confirmed by contrast enhancement that the stenosis is not fully expanded, the balloon is repeatedly expanded until the stenosis is fully expanded, and the balloon is guided to the lesion site and expanded. It is necessary.
[0006]
When such a balloon catheter is provided as a product, as shown in the schematic cross-sectional view of FIG. 10A, the balloon 62 is deflated and the outer diameter thereof is minimized to surround the guide wire passing tube 66. In a folded state. Therefore, at the first use, the balloon 62 passes through the constricted portion without difficulty, and the balloon 62 is expanded by increasing the internal pressure, as shown in the schematic sectional view of FIG. However, even if the balloon 62 is contracted under reduced pressure when it is removed from the body, the folded state does not return to the folded state shown in FIG. The phenomenon that both wings 68a and 68b are formed horizontally (referred to as winging) occurs, and the overall length of the wings (hereinafter referred to as winging length) is not limited to the outer diameter of the balloon in the folded state. Since it becomes larger than a nominal diameter, there exists a problem that it is difficult to perform a dilation treatment again using the balloon. That is, as shown in FIG. 11, the tapered portion 69B divided by the two wings 68a and 68b hits the constricted portion 72 of the lumen of the blood vessel 71 and may not be able to advance any further. This is considered because the distal side taper portion 69B at the time of winging forms a steep step. In particular, when a balloon with such winging is passed through a hard lesion site due to calcification or stent placement, the operator feels a great resistance, and if the balloon is forced to advance, the stent is vascularized. There is a significant risk of pushing to the distal side of the stent and causing stent misalignment.
[0007]
The same kind of problem as described above is also described in detail in Japanese Patent No. 26711961, and a balloon catheter that can return the balloon to a folded state without causing winging is disclosed. This balloon catheter is provided with a balloon with longitudinal grooves in the longitudinal direction, the longitudinal grooves disappear in the balloon when expanded, and the balloon when contracted returns to the folded state along the longitudinal grooves.
[0008]
However, the balloon described in the above publication has a problem that a longitudinal groove remains at the time of expansion unless an internal pressure higher than a certain level is applied, and the outer shape of the cross section does not become a perfect circle. This is because if the outer shape of the cross section is not a perfect circle, the constricted portion cannot be expanded uniformly over the entire circumference, and there is a high risk that restenosis will occur in a short period of time.
[0009]
[Problems to be solved by the invention]
In view of the above problems, the present invention intends to solve the problem that the high resistance force at the time of indentation due to the influence of winging is greatly increased even when re-passing through a hard lesion site where calcification has occurred or a stent is placed. It is the point which provides the balloon catheter provided with the balloon which can be reduced to this.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, there is provided a straight tube portion at a distal end of a catheter shaft having a guide wire passing tube disposed inside an outer tube, and adjacent to both ends of the straight tube portion. A medical balloon catheter configured by joining a balloon having proximal and distal taper portions that gradually reduce in diameter and proximal and distal sleeve portions adjacent to both ends of the taper portions. Because at least Said distal sleeve Part , Having a shape that shifts a part of the taper start position adjacent to the sleeve portion in the long axis direction, The taper start position over the inner periphery of the distal end of the distal taper portion 12B gradually shifts to the distal side in the circumferential direction starting from the taper start position 16b on the most proximal side, and the taper start on the most distal side starts. Molded to have a shape that reaches position 16a The inner surface of the distal sleeve and the guide wire Ya The outer surface of the passage tube is joined, and the proximal sleeve portion and the end portion of the outer tube are joined.
[0011]
Here, it is preferable to adjust the deviation in the major axis direction of the taper start position adjacent to the sleeve portion within a range of 0.3 mm to 10.0 mm.
[0012]
Further, the second aspect of the present invention provides a straight tube portion at a distal end of a catheter shaft in which a guide wire passing tube is disposed inside the outer tube, and a diameter near the both ends of the straight tube portion that gradually decreases in diameter. A medical balloon catheter configured by joining balloons each having a distal side and a distal side tapered portion and proximal and distal side sleeve portions adjacent to both ends of the tapered portion; at least The distal taper Part Change the inclination angle over the circumferential direction, The distal taper portion 32B has a shape in which the inclination angle starts from the minimum value (θ2) and gradually changes in the circumferential direction to reach the maximum value (θ1). The inner surface of the distal sleeve and the guide wire Ya The outer surface of the passage tube is joined, and the proximal sleeve portion and the end portion of the outer tube are joined.
[0013]
Here, it is preferable to adjust the difference between the maximum value and the minimum value of the tilt angle within a range of 2 ° to 30 °.
[0014]
And in the said 1st and 2nd invention, it is desirable to adjust the length of the long axis direction of a straight pipe part in the range of 8 mm-80 mm.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, various embodiments of a medical balloon catheter according to the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a schematic cross-sectional view showing the vicinity of the distal end portion of a first embodiment of a balloon catheter 1 according to the first invention.
[0017]
The balloon catheter 1 of this embodiment is formed by joining a balloon 10 to a catheter shaft 2 in which a guide wire passing tube 4 is disposed in the lumen of an outer tube 3, and the balloon 10 has a tube shape. The straight tube portion 11 that expands or contracts by adjusting the internal pressure, the proximal and distal taper portions 12A and 12B that are gradually reduced in diameter adjacent to both ends of the straight tube portion 11, and both ends of the taper portions 12A and 12B And proximal and distal sleeve portions 13A and 13B joined to the distal end of the outer tube 3 and the outer peripheral surface of the guide wire passing tube 4.
[0018]
The outer peripheral surface of the distal end of the outer tube 3 is reduced in diameter in consideration of pressure resistance, and the proximal sleeve portion 13A is externally joined to the reduced diameter portion. Thereby, the level | step difference which arises after both joining can be made small. Further, an inflation lumen 14 through which a pressure fluid such as a physiological saline or a contrast medium introduced to apply an internal pressure to the balloon 10 is passed between the outer peripheral surface of the guide wire passing tube 4 and the inner peripheral surface of the outer tube 3. The above-described guide wire is inserted into the lumen (guide wire lumen) 15 of the guide wire passing tube 4. Further, the most distal end 4a of the guide wire passing tube 4 is processed into a tapered shape whose outer diameter gradually decreases toward the tip so that the distal end 4a can smoothly advance in a narrow blood vessel or a highly narrowed portion. Yes. Note that a manifold having a port communicating with the inflation lumen 14 and the guide wire lumen 15 is connected to the catheter shaft proximal end (not shown).
[0019]
Further, the distal sleeve portion 13B is shaped so that a part 16a of the adjacent taper start position is shifted by a predetermined distance (Ld) to the long axis direction distal side, more specifically, the distal side The taper start position over the inner periphery of the distal end of the taper portion 12B gradually shifts to the distal side in the circumferential direction starting from the taper start position 16b on the most proximal side, and reaches the taper start position 16a on the most distal side. It is molded so as to have a variety of shapes. At this time, the long-axis direction distance between the taper start positions 16b and 16a between the most proximal side and the most distal side is Ld shown in the figure. FIG. 2 shows a schematic cross-sectional view of the straight pipe portion 11 when such balloon 10 is winged. According to the figure, in the straight tube portion 11 of the balloon 10, both wings 11a and 11b are formed around the guide wire passing tube 4, and these wings 11a and 11b are farthest from the nearest side. The taper start positions 16b and 16a with respect to the rear side are generated as starting points. As a result, the generation positions of both wings 11a and 11b can be controlled, and the distal taper portion 12B at the time of occurrence of winging appears as being divided into two wings 11a and 11b. As a result, two steps are formed, and no sharp steps are formed. Therefore, the resistance force when passing a balloon with winging to a calcified or stented lesion site is greatly reduced. In order to sufficiently exhibit the above effects, the Ld is preferably adjusted within a range of 0.3 mm to 10.0 mm, particularly 0.5 mm to 8 mm.
[0020]
Further, the straight tube portion 11 is a portion from the terminal position of the distal tapered portion 12B to the terminal position of the proximal tapered portion 12A, and is a portion that substantially expands the lesion site. When the taper start position 16a of the distal taper portion 12B is shifted to the distal side, the corresponding taper end position is also shifted to the distal side, and the length of the straight tube portion 11 in the long axis direction is not constant but is circumferential. It will gradually change over the direction. The shortest stenosis length in the coronary artery to be treated with the PTCA balloon catheter is about 8.0 mm, and the other vascular lumen to be treated with the PTA balloon catheter is about 80.0 mm in the subclavian vein or the like. In order to deal with these various lesion sites, the length of the straight tube portion 11 in the long axis direction is preferably adjusted within the range of 8.0 mm to 80.0 mm at the shortest portion. It is.
[0021]
Such a balloon 10 is preferably produced by a blow molding method in order to have sufficient strength against the internal pressure introduced during expansion. Specifically, first, a tube-shaped parison having a predetermined inner diameter and outer diameter is produced by extrusion molding, and this parison is stretched to a length of 2 to 7 times in the axial direction at room temperature. Both the outer portions in the axial direction of the portion formed in the tube portion, that is, the portions formed later in the tapered portion and the sleeve portion are locally heated, and only the both outer portions are pulled and stretched in the axial direction. Thereby, it is possible to sufficiently thin the tapered portion and the sleeve portion after molding.
[0022]
The parison thus preformed to have a predetermined length is transferred to a cavity in a blow molding die, the die is closed, and compressed air is blown into the inside to inflate the parison, and mold the cavity into the above balloon. The straight pipe portion 11, the tapered portions 12A and 12B and the sleeve portions 13A and 13B are formed. The cavity shape is preferably set to be slightly larger than the shape of the balloon that is a molded product. Moreover, in order to stabilize the shape dimension of a balloon, you may perform a heat setting process as needed. Examples of the resin material used for the parison include polyethylene terephthalate (PET), polyethylene, polyvinyl acetate, ionomer, polyvinyl chloride, polyamide (nylon 66, nylon 12, etc.), polyamide thermoplastic elastomer, polyester thermoplastic elastomer, and polyurethane. One type or a mixture of two or more types such as a thermoplastic elastomer can be used, and a multi-layered parison combining these resin materials can be prepared. The present invention is not limited to the production conditions and materials of the balloon, and is described in, for example, JP-A-3-57462, JP-A-3-57463, and JP-B-3-37949. Manufacturing conditions and materials may be used.
[0023]
Further, after the above blow molding, the straight tube portion and the taper portion are fixed with a mold in order to more accurately reduce the thickness of the proximal and distal sleeve portions, and the proximal sleeve portion or the distal portion is fixed. Only the side sleeve portion may be pulled and stretched, or the sleeve portion may be subjected to grinding processing such as centerless grinding in order to make it thinner.
[0024]
Further, the outer tube 3 and the guide wire passing tube 4 constituting the catheter shaft 2 are formed by an extrusion method when made of a thermoplastic resin, and dip / cure forming method when made of a thermosetting resin such as polyimide. It is produced by. For the outer tube 3, nylon, polyamide elastomer, polyester elastomer, polyurethane elastomer, polyethylene, and the like that are relatively soft and have low flexural modulus and tensile strength are suitable. In particular, the guide wire passing tube 4 is made of high-density polyethylene or the like in order to ensure good slipperiness with respect to the guide wire, and a clearance of about 0.014 mm between the guide wire lumen and the inserted guide wire. Is preferably provided. Unlike the soft outer tube material, the proximal outer tube material connected to the manifold located at the proximal end is relatively hard and has a flexural modulus and tensile strength, unlike the soft outer tube material. It is preferable to use a high material.
[0025]
Next, a second embodiment of the balloon catheter according to the second invention will be described. FIG. 3 is a schematic cross-sectional view showing the vicinity of the tip of the present embodiment.
[0026]
The balloon catheter 20 of the present embodiment is formed by joining a balloon 30 to a catheter shaft 2 in which a guide wire passing tube 4 is disposed inside an outer tube 3, and this balloon 30 has a tube shape, A straight pipe portion 31 that expands or contracts by adjusting the internal pressure, proximal and distal tapered portions 32A and 32B that are adjacent to both ends of the straight pipe portion 31 and gradually reduce in diameter, and both ends of the tapered portions 32A and 32B. Proximal and distal sleeve portions 33A and 33B adjacent to each other and joined to the distal end portion of the outer tube 3 and the outer peripheral surface of the guide wire passing tube 4 are configured. . It should be noted that constituent members having the same reference numerals as those in the first embodiment have substantially the same configuration, and a detailed description thereof will be omitted. Further, the method for joining the proximal sleeve portion 33A and the outer tube 3, the method for bonding the guide wire passing tube 4 and the distal sleeve portion 33B, and their materials are substantially the same as in the first embodiment. Therefore, detailed description is omitted.
[0027]
The angle of inclination of the distal taper portion 32B with respect to the major axis direction gradually changes. Specifically, the distal taper portion 32B has an inclination angle starting from a minimum value (θ2) as shown in the figure, It is formed so as to have a shape that gradually changes in the circumferential direction and reaches the maximum value (θ1). Therefore, as shown in the schematic cross-sectional view of the straight pipe portion 31 in FIG. 4, even if both wings 31a and 31b are generated around the guide wire passing tube 4 when winging occurs, the both wings 31a and 31b are inclined. A position corresponding to the maximum value (θ1) and the minimum value (θ2) of the angle is generated as a starting point. As a result, the generation position of both wings 31a and 31b can be controlled, and the distal taper portion 32B at the time of winging appears divided by the both wings 31a and 31b, but does not form a steep step. In addition, the resistance force when the balloon in which winging has occurred passes through a calcified or stented lesion site or the like is greatly reduced. In order to sufficiently reduce the resistance, the angle difference (θ1−θ2) between the maximum value and the minimum value of the inclination angle is in the range of 2 ° to 30 °, particularly 5 ° to 25 °. It is preferable to adjust inward.
[0028]
Further, the straight pipe portion 31 is a portion that extends from the terminal position of the distal taper portion 32B to the terminal position of the proximal taper portion 32A and substantially expands the lesion site. In this embodiment, when the inclination angle of the distal taper portion 32B is changed, the terminal position of the corresponding distal taper portion 32B is also shifted in the long axis direction, and the length in the long axis direction of the straight pipe portion 31 is reduced. It will change over the direction. The length in the major axis direction of such a straight pipe portion 31 is adjusted within the range of 8.0 mm to 80.0 mm at the shortest portion to cope with various lesion sites for the same reason as in the first embodiment. It is preferred that
[0029]
As described above, in each of the above-described embodiments, the configuration of the distal sleeve portion has been mainly described. However, in the present invention, it is possible to adopt the same configuration for the outer tube with respect to the proximal sleeve portion. . In this case, since the resistance force when the balloon catheter is retracted can be reduced, the risk of causing postoperative complications by damaging the intima of the blood vessel can be reduced.
[0030]
Further, by combining the first embodiment and the second embodiment and optimally adjusting the shift distance of the taper start position and the difference between the maximum inclination angle and the minimum inclination angle of the tapered portion, a more preferable balloon catheter can be obtained. It will be obvious to those skilled in the art.
[0031]
In the above embodiment, the co-axial type catheter has been described. However, the present invention can be applied to balloon catheters other than the co-axial type, and is described in, for example, JP-A-7-132147. Needless to say, it can be applied to a type having a plurality of axes. Furthermore, the present invention may be applied to various balloon catheters such as an over-the-wire type and a monorail type depending on the application.
[0032]
It is obvious to those skilled in the art that the present invention represented by the above embodiment is applicable not only to PTCA balloon catheters for treating coronary artery stenosis but also to peripheral blood vessels other than coronary arteries and applicable to dialysis shunts. Of course, it can be applied to any lumen in the body that is difficult to pass through the balloon.
[0033]
【Example】
Hereinafter, although the more concrete Example and comparative example which concern on this invention are explained in full detail, the following Examples do not limit this invention at all.
[0034]
Example 1
As shown in FIG. 1, the balloon catheter 1 of the first embodiment was produced. That is, the catheter shaft 2 is a co-axial type having a double tube structure in which the guide wire passage tube 4 is disposed in the lumen of the outer tube 3. A polyethylene tube having an inner diameter of 0.42 mm, an outer diameter of 0.56 mm, and a total length of about 30 cm is used. As the outer tube 3, the inner diameter is 0.70 mm, the outer diameter is 0.88 mm, and the total length is about 25 cm. A tube made of polyamide resin “PEBAX” (model number “7233SA00”; manufactured by Atochem) was used. The normal catheter shaft has a total length of about 135 cm and is composed of a proximal segment having a total length of about 105 cm and a distal segment having a total length of about 30 cm. In this embodiment, Since it is sufficient to evaluate only the distal side, the configuration of the proximal segment is not adopted.
[0035]
The procedure for producing the balloon 10 to be joined to the distal end of the catheter shaft 2 is as follows. First, a parison (inner diameter 0.60 mm; outer diameter 1.03 mm) using “Hytrel” (manufactured by DuPont; Shore hardness 72D) as the resin material is stretched and stretched three times in the axial direction at room temperature, A 13 mm long central 3 cm portion on both outer sides in the axial direction is locally heated (temperature 90 ° C.), and the outer 3 cm portions are further stretched twice in the axial direction to prepare a preformed parison. To do. Thereafter, the parison is transferred to the cavity of the blow mold, the end of the cavity is plugged, and a high-pressure air source is connected to the other end. Next, the mold was closed and heated to about 90 ° C., and 280 psi of air was blown into the interior of the parison to form a balloon having a nominal diameter (balloon diameter when a nominal pressure of 6 atm was applied) of 3.0 mm. .
[0036]
As shown in FIG. 5, the dimension of each part of the balloon 10 is such that the length of the straight tube portion 11 in the major axis direction is 18.0 mm, the wall thickness is 0.020 mm, and the inner diameter of the distal sleeve portion 13B is 0.00. 57 mm, the outer diameter is 0.70 mm, the difference (Ld) between the taper start positions 16a and 16b between the most distal side and the most proximal side of the sleeve portion is 3.0 mm, and the minimum length of the sleeve portion is 2 0.0 mm, the length of the distal tapered portion 12B in the major axis direction is 4.5 mm, the length of the proximal tapered portion 12A in the major axis direction is 4.1 mm, and the length of the proximal sleeve portion 13A is 3. 0 mm, its inner diameter is 0.89 mm, and its outer diameter is 0.99 mm.
[0037]
Such a balloon 10 is joined to the catheter shaft 2 using an adhesive “4011” (manufactured by Loctite), the proximal end of the catheter shaft 2 is connected to a manifold, and the balloon catheter of the present embodiment (distal) Side segment). Here, the proximal sleeve portion 13A is externally fitted and joined to a portion whose diameter is reduced across the outer diameter of the distal end of the outer tube 3 (length in the long axis direction is 3 mm), and the distal sleeve portion 13B. Were joined to the outer peripheral surface of the guide wire passing tube 4 (adhesive margin is 2 mm in the long axis direction).
[0038]
(Comparative example)
A balloon catheter of this comparative example was produced in the same manner as in Example 1 except that the size and shape of each part of the balloon were set as shown in FIG. As shown in FIG. 6, the dimensions of the balloon 40 according to this comparative example are as follows. The length of the straight tube portion 41 in the major axis direction is 18.0 mm, the wall thickness is 0.020 mm, and the distal sleeve portion 42B The inner diameter is 0.57 mm, the outer diameter is 0.70 mm, the length is 2.0 mm, the length in the major axis direction of the distal taper portion 43B is 4.5 mm, and the major axis direction of the proximal taper portion 43A The length is 4.1 mm, the length of the proximal sleeve portion 42A is 3.0 mm, the inner diameter is 0.89 mm, and the outer diameter is 0.99 mm. The distal sleeve portion 42B was formed such that the inclination angle with respect to the major axis direction was constant over the circumferential direction (θ1 = θ2).
[0039]
(Evaluation methods)
An experimental system as shown in FIG. 7 was used. That is, a metal tube 51 with an inner diameter of 3.0 mm and a major axis length of 5 cm is abutted and coaxially connected to the distal end surface of a polyurethane tube 50 having an inner diameter of 3.5 mm and a major axis length of 20 cm. Then, an experimental environment assuming a blood vessel lumen having a stenosis is prepared, a guide wire 52 is inserted through these tube lumens, and then a balloon catheter 53 that intentionally generates horizontal winging is used as the guide wire. When the balloon 54 passes through the boundary between the polyurethane tube 50 and the metal tube 51, the maximum value of the reading of the force gauge 57 fixed to the manifold 55 using the holding jig 56 is set. Recorded as measured values, the balloon catheter was evaluated based on each measured value. The inner diameter of the metal tube 51 is set to be smaller than the winging length over both the wings 54a and 54b of the balloon 54.
[0040]
(Evaluation result 1)
The measured values with the balloon catheters of Example 1 and Comparative Example using the above experimental system are Example 1: 28 gram weight, Comparative Example: 51 gram weight, and Example 1 is compared with Comparative Example. It was confirmed that the resistance force was greatly reduced.
[0041]
(Example 2)
Next, as shown in FIG. 3, the balloon catheter of the second embodiment was manufactured, and the dimensions and shape of each part of the balloon were set as shown in FIG. Example balloon catheters were prepared. As shown in FIG. 8, the size of each part of the balloon 30 is such that the maximum inclination angle (θ1) of the distal tapered portion 32B is 15 °, the minimum inclination angle (θ2) is 8 °, and the difference (θ1−θ2) is 7 °, the length of the straight pipe portion 31 in the major axis direction is 18.0 mm, the thickness is 0.020 mm, the inner diameter of the distal sleeve portion 33B is 0.57 mm, the outer diameter is 0.70 mm, The length is 2.0 mm, the length of the proximal sleeve portion 33A is 3.0 mm, the inner diameter is 0.89 mm, and the outer diameter is 0.99 mm.
[0042]
(Evaluation result 2)
The measured values of the balloon catheters of Example 2 and the comparative example are as follows: Example 2: 38 gram weight, Comparative example: 51 gram weight. Also in Example 2, the taper start position of the distal tapered portion is Compared with the comparative example which is the same over the circumferential direction, it was confirmed that the resistance force was significantly reduced.
[0043]
【The invention's effect】
As described above, according to the medical balloon catheter of the first invention, at least Said distal sleeve Part , Having a shape that shifts a part of the taper start position adjacent to the sleeve portion in the long axis direction, The taper start position over the inner periphery of the distal end of the distal taper portion 12B gradually shifts to the distal side in the circumferential direction starting from the taper start position 16b on the most proximal side, and the taper start on the most distal side starts. Molded to have a shape that reaches position 16a The inner surface of the distal sleeve and the guide wire Ya Since the outer surface of the passage tube is joined and the proximal sleeve portion and the end of the outer tube are joined, the distal taper portion at the time of occurrence of winging appears to be divided into two wings. Since the position is shifted in the long axis direction, a two-step difference is formed, and a sharp step is not formed. Therefore, the resistance when passing a winged balloon to a lesion site where calcified or stented is greatly increased. The risk of damaging the lumen of the blood vessel or pushing the stent to the distal side of the blood vessel and causing displacement of the stent is greatly reduced.
[0044]
According to the medical balloon catheter of the second invention, at least Distal taper Part Change the tilt angle over the circumferential direction The distal tapered portion 32B has a shape in which the inclination angle starts from the minimum value (θ2) and gradually changes in the circumferential direction to reach the maximum value (θ1). Therefore, the distal taper portion at the time of occurrence of winging appears as being divided into two wings, but does not form a steep step, so that the balloon in which winging has occurred is calcified or stented as in the first invention. It becomes possible to greatly reduce the resistance when passing through a hard lesion site or the like.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of a balloon catheter according to the present invention.
FIG. 2 is an explanatory view showing a state in which winging has occurred in the balloon catheter of the first embodiment.
FIG. 3 is a schematic sectional view showing a second embodiment of the balloon catheter according to the present invention.
FIG. 4 is an explanatory view showing a state in which winging has occurred in the balloon catheter of the second embodiment.
5 is a schematic cross-sectional view showing dimensions of each part of a balloon according to Example 1. FIG.
FIG. 6 is a schematic cross-sectional view showing dimensions of each part of a balloon according to a comparative example.
FIG. 7 is a schematic diagram for explaining an experimental environment.
8 is a schematic cross-sectional view showing the dimensions of each part of a balloon according to Example 2. FIG.
FIG. 9 is a schematic sectional view showing a conventional balloon catheter.
10A and 10B are schematic cross-sectional views showing a state of a straight tube portion of a balloon catheter, where FIG. 10A is a folded state, FIG. 10B is an expanded state, and FIG.
FIG. 11 is a schematic explanatory view showing a state where a balloon catheter in which winging has occurred hits a stenosis.
[Explanation of symbols]
1 Balloon catheter
2 Catheter shaft
3 Outer tube
4 Guide wire passing tube
4a The most distal end of the guide wire passing tube
10 Balloon
11 Straight pipe section
11a, 11b Wings generated in the straight pipe part in the winging state
12A proximal taper
12B Distal taper
13A Proximal sleeve
13B Distal sleeve
14 Inflation lumen
15 Guidewire lumen
16a Taper start position on the most distal side
16b Taper start position on nearest side
20 Balloon catheter
30 balloon
31 Straight pipe section
32A proximal taper
32B Distal taper
33A Proximal sleeve
33B Distal sleeve
40 balloon
41 Straight pipe section
42A Proximal sleeve
42B Distal sleeve
43A proximal taper
43B Distal taper
50 Polyurethane tube
51 Metal tube
52 Guidewire
53 Balloon Catheter
54 Balloon
55 Manifold
56 Holding jig
57 force gauge
60 balloon catheter
61 Catheter shaft
62 Balloon (expanded body)
63 Manifold
64 Inflation lumen
65 Outer tube (outer tube)
66 Guide wire passage tube (inner tube)
67 Guidewire lumen
68 Straight pipe
69A, 69B Taper
70A, 70B Sleeve part
71 blood vessels
72 Stenosis

Claims (5)

A straight tube portion at the distal end of a catheter shaft in which a guide wire passing tube is disposed inside the outer tube, and proximal and distal tapers that gradually decrease in diameter adjacent to both ends of the straight tube portion. A balloon balloon for medical use configured by joining a balloon having a portion and a proximal side and a distal side sleeve portion adjacent to both ends of the tapered portion,
At least the distal sleeve portion has a shape in which a part of the taper start position adjacent to the sleeve portion is shifted in the long axis direction, and the taper start position over the inner periphery of the distal end of the distal taper portion 12B. The taper starting position 16b on the most proximal side is gradually shifted to the distal side in the circumferential direction starting from the taper starting position 16b on the most proximal side, and is shaped so as to reach the taper starting position 16a on the most distal side ,
Medical balloon catheter, characterized in that the inner surface of the distal sleeve and the guide wire Ya and the outer surface of the passage tube are joined and the proximal sleeve portion and the end portion of the outer tube is formed by joining .   The medical balloon catheter according to claim 1, wherein a deviation in a major axis direction of a taper start position adjacent to the sleeve portion is adjusted within a range of 0.3 mm to 10.0 mm. A straight tube portion at the distal end of a catheter shaft in which a guide wire passing tube is disposed inside the outer tube, and proximal and distal tapers that gradually decrease in diameter adjacent to both ends of the straight tube portion. A balloon balloon for medical use configured by joining a balloon having a portion and a proximal side and a distal side sleeve portion adjacent to both ends of the tapered portion,
At least the inclination angle of the distal taper portion is changed in the circumferential direction, and the inclination angle of the distal taper portion 32B starts from the minimum value (θ2) and gradually changes in the circumferential direction to the maximum value (θ1 ) To have a shape that leads to
Medical balloon catheter, characterized in that the inner surface of the distal sleeve and the guide wire Ya and the outer surface of the passage tube are joined and the proximal sleeve portion and the end portion of the outer tube is formed by joining .   The medical balloon catheter according to claim 3, wherein a difference between the maximum value and the minimum value of the inclination angle is adjusted within a range of 2 ° to 30 °.   The medical balloon catheter according to any one of claims 1 to 4, wherein a length of the straight pipe portion in a major axis direction is adjusted within a range of 8 mm to 80 mm.

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