JP2014069034A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter capable of suppressing restenosis of a location expanded by a balloon.SOLUTION: A balloon catheter 10 comprises: a shaft 11 that is inserted into a blood vessel from its tip side; a balloon 12 that is provided on the tip side of the shaft 11 and is inflated and deflated by a fluid to be flown into and flown out from an internal space; a connector 13 that is provided on a base end side of the shaft 11; and a wire 14 that is allowed to extend along each outer surface of the balloon 12 and the shaft 11. The wire 11 includes: a channel 32 that allows the fluid to flow inside; and through-holes 33 that are provided on a peripheral wall of the tip side and are continuous with the channel 32.

Description

  The present invention relates to a balloon catheter used for endovascular treatment.

  Conventionally, treatment for expanding stenosis due to atheroma (or plaque) in blood vessels has been performed. Such endovascular treatment is called intervention. For example, in order to expand a stenosis portion of a blood vessel such as an atheroma (or plaque) with a balloon catheter, first, the distal end of the guide wire is positioned near the stenosis portion, and a guiding catheter or a sheath introducer is inserted into the blood vessel. . The balloon catheter is inserted into the guiding catheter so as to be guided by the guide wire, and the balloon is positioned in the stenosis portion. Then, the balloon is inflated to expand the narrowed portion.

  If the stenosis part of the blood vessel is hardened by calcification or the like, the stenosis part may not expand even if the balloon is inflated. When the balloon is inflated in a state where the constricted portion is not expanded, so-called dog boning occurs in which only both ends of the balloon are inflated. In order to expand such a hardened narrowed portion, a balloon having a metal blade called a cutting blade is known (see Patent Document 1). The cutting blade is expected not only to cut the hardened stenosis part but also to prevent the balloon from being displaced from the stenosis part. In that case, in order to acquire the said effect, a scoring wire is provided in a balloon.

JP 2008-519654 A

  However, even if the stenosis portion of the blood vessel is expanded using a balloon catheter provided with a cutting blade or a scoring wire, there is a concern that the expanded portion may be restenulated after the operation.

  This invention is made | formed in view of such a situation, The objective is to provide the balloon catheter which can suppress that the location expanded by the balloon is restenosis.

  (1) A balloon catheter according to the present invention is provided on the distal end side of the shaft, the shaft having a first flow channel that is inserted into the blood vessel from the distal end side and through which fluid can flow, and the first flow A balloon which is inflated and deflated by fluid flowing into and out of the internal space through the passage, a connector provided on the proximal end side of the shaft, and extending along the outer surface of the balloon and the shaft; A wire rod having an end fixed to the distal end side of the balloon and a second end extending toward the connector. The wire has a second flow path through which a fluid can flow, and a through hole provided in the peripheral wall on the first end side and continuing to the second flow path.

  The balloon catheter is inserted into the blood vessel from the tip of the shaft with the balloon deflated. The connector is positioned outside the blood vessel for shaft operation, fluid inflow and outflow, and the like. In a state where the balloon is positioned at a stenosis site such as an atheroma (or plaque), the balloon is inflated by the flow of fluid into the first flow path. When the balloon is inflated, the blade of the wire rod is pushed by the balloon to bend along the shape of the inflated balloon. As a result, the wire is brought into contact with the hardened stenosis part, and a cut is made in the stenosis part or the balloon is prevented from being displaced from the stenosis part. In a state where the balloon is inflated, a medicine for suppressing restenosis is flowed into the second flow path of the wire. The drug is released out of the wire through the through hole and applied to the stenosis site. Thereafter, the balloon catheter is withdrawn from the blood vessel as the balloon is deflated.

  (2) The plurality of through holes may be arranged to be separated from each other in the axial direction of the wire. Thereby, the medicine is applied over a wide range of blood vessels.

  (3) In a state where the balloon is inflated, the through hole may be provided outside the balloon and at a position facing the radially outward direction of the shaft. Thereby, since the inner wall of the blood vessel and the through hole face each other, the medicine released from the through hole is directly applied to the inner wall.

  (4) A hub to which a syringe can be connected may be provided at the second end of the wire. Thereby, a syringe can be used and a chemical | medical agent can flow in into the 2nd flow path of a wire.

  According to the balloon catheter according to the present invention, since the drug is applied to the portion expanded by the balloon through the second flow path and the through hole of the wire provided along the balloon and the shaft, the portion is restenulated. It is suppressed.

FIG. 1 is a diagram showing an external configuration of the balloon catheter 10 in a state where the balloon 12 is in a contracted posture. FIG. 2 is a longitudinal sectional view of the balloon catheter 10 of FIG. FIG. 3 is a partially enlarged view showing the balloon 12 in an inflated posture. 4 is a partially enlarged sectional view taken along arrow IV in FIG. FIG. 5 is a diagram showing an external configuration of a balloon catheter 10 according to a modification.

  Hereinafter, preferred embodiments of the present invention will be described. In addition, this embodiment is only one embodiment of this invention, and it cannot be overemphasized that an embodiment can be changed in the range which does not change the summary of this invention.

  As shown in FIG. 1, a balloon catheter 10 includes a shaft 11 having a double lumen structure, a balloon 12 provided on the distal end side of the shaft 11, a connector 13 provided on the proximal end side of the shaft 11, and a shaft. 11 and a wire rod 14 provided along the line 11.

  As shown in FIG. 2, the shaft 11 has a double lumen structure having a first lumen 21 and a second lumen 22 therein. The first lumen 21 is formed at the central portion along the axis 101 of the shaft 11, and the second lumen 22 is formed outside the first lumen 21. The material of the shaft 11 is preferably a biocompatible material, and specific examples include polyurethane, polyethylene, porester, polypropylene, polyether block amide, polyamide, polytetrafluoroethylene, and polyvinylidene fluoride. The shaft 11 has a substantially uniform outer diameter over the axial direction 101. The first lumen 21 and the second lumen 22 also have substantially uniform inner diameters in the axial direction 101. The inner diameter of the first lumen 21 is set to a diameter capable of inserting a guide wire. The second lumen 22 is a space through which a fluid such as a contrast medium or physiological saline or air can flow. The length of the shaft 11 in the axial direction 101 is appropriately set in consideration of the length from the catheter insertion part such as a human limb to the affected part. The second lumen 22 corresponds to the first flow path of the shaft according to the present invention.

  A balloon 12 is provided on the distal end side of the shaft 11. The balloon 12 has a bag shape that prevents blood from passing in the thickness direction. The internal space of the bag-shaped balloon 12 is in communication with the second lumen 22. The posture of the balloon 12 is changed between an inflated posture and a deflated posture by the fluid flowing into and out of the internal space. The material of the balloon 12 is preferably a biocompatible material. Specific examples include polyurethane, polyethylene, polyester, polypropylene, polyether block amide, polyamide, polytetrafluoroethylene, and polyvinylidene fluoride.

  As shown in FIG. 3, the balloon 12 in the inflated posture has a cylindrical shape at the center in the longitudinal direction (corresponding to the axial direction 101 in FIG. 3), and both ends are reduced in diameter to a tapered shape. The outer diameter of the balloon 12 in the inflated posture is designed according to the thickness of the blood vessel into which the balloon catheter 10 is inserted. As shown in FIG. 1, the balloon 12 in the contracted posture has an outer diameter slightly larger than that of the shaft 11. When fluid flows out from the inner space of the balloon 12 in the inflated posture, the balloon 12 is deflated inward so that several places in the circumferential direction are folded. In the balloon 12, a portion that is deflated inward is set in advance by brazing. In the balloon 12, several places in the circumferential direction are deflated inward, so that the balloon 12 is folded so that the valleys are continuous in the circumferential direction, and the mountain portion wraps around in the circumferential direction so that an umbrella is wound. As a result, the balloon 12 is in a contracted posture. Such expansion and contraction of the balloon 12 is realized in the same manner as known means used in a balloon of a balloon catheter.

  The shaft 11 is inserted into the blood vessel from the distal end side where the balloon 12 is provided. A connector 13 is provided at the proximal end of the shaft 11. The connector 13 is a cylindrical member having an internal space continuous with the first lumen 21 and the second lumen 22. The connector 13 is a molded body of a resin such as polycarbonate, polypropylene, or ABS. The connector 13 can be a handle in operations such as insertion and removal of the shaft 11.

  A first port 23 is provided at the proximal end of the connector 13. The first port 23 is provided on the axis 101 of the shaft 11 and communicates with the first lumen 21. Further, the connector 13 is provided with a second port 24 that extends in a direction intersecting the axis 101 of the shaft 11. The second port 24 communicates with the second lumen 22. Through the second port 24, fluids such as air, physiological saline, and contrast medium flowing in and out from other devices flow into and out of the second lumen 22.

  As shown in FIGS. 2 to 4, a wire 14 is provided along the axis 101 on the outside of the shaft 11. The wire 14 is an elongated cylindrical member having a flow path 32 through which a liquid medicine can flow and is made of metal, alloy, or the like and can be elastically bent. The distal end (first end) of the wire 14 is fixed to a tube 20 provided on the distal end side of the balloon 12 in the shaft 11. Since the tube 20 and the wire 14 are joined by welding or adhesion, the tube 20 is preferably made of the same material as the wire 14. Note that the tip of the wire 14 may be directly fixed to the shaft 11 via a member other than the tube 20 or directly. Moreover, the flow path 32 may be opened at the front-end | tip of the wire 14, and may be obstruct | occluded. The channel 32 corresponds to the second channel. The tip of the wire 14 corresponds to the first end, and the base end of the wire 14 corresponds to the second end.

  The tube 20 is externally fitted to the distal tip 30 of the shaft 11 and is fixed to the distal tip 30 by welding or adhesion. The distal tip 30 may be embedded with a metal material that can be confirmed by X-rays in order to grasp the position of the balloon catheter 10.

  The proximal end (second end) of the wire rod 14 extends to the vicinity of the connector 13. A hub 31 to which a syringe port (not shown) can be connected is provided at the proximal end of the wire 14. The hub 31 serves as an inlet to the flow path 32 on the proximal end side of the wire 14.

  The wire 14 is not fixed to the shaft 11 and the balloon 12 except for the tube 20. Therefore, portions other than the tip of the wire 14 can be bent separately from the shaft 11.

  The wire 14 extends along the outer surface of the shaft 11 and the balloon 12, and as shown in FIG. 3, when the balloon 12 is expanded, the wire 14 is pushed by the balloon 12. Elastically bends in the direction of expansion, i.e., away from the axis 101.

  As shown in FIG. 4, a plurality of through holes 33 penetrating the peripheral wall of the wire 14 are provided in a region corresponding to the balloon 12 of the wire 14 in the axial direction 101. Each through-hole 33 is continuous with the flow path 32 that is the internal space of the wire 14.

  Each through-hole 33 is provided at a position on the outer side of the balloon 12 in an inflated posture and facing outward in the radial direction of the shaft 11. In addition, the plurality of through holes 33 are spaced apart in the axial direction 101.

  The cross-sectional shape of the wire 14 need not be constant over the longitudinal direction, and the shape of the surface of the portion corresponding to the balloon 12, the portion along the shaft 11, and the portion corresponding to the inside of the connector 13 is different. It may be. For example, the portion of the wire 14 corresponding to the balloon 12 may have a shape that is sharpened at an acute angle in a direction away from the axis 101 of the shaft 11.

[Method of using balloon catheter 10]
Below, the usage method of the balloon catheter 10 is demonstrated.

  The balloon catheter 10 is used when dilating a narrowed portion of a blood vessel such as an atheroma (or plaque). As shown in FIG. 1, the balloon catheter 10 is inserted into the blood vessel from the distal end of the shaft 11 along the guide wire in a state where the balloon 12 is in a contracted posture. The shaft 11 and the wire 14 are appropriately deformed according to the shape of the blood vessel when inserted into the blood vessel.

  When the balloon 12 is inserted up to the narrowed portion of the blood vessel, the insertion of the shaft 11 into the blood vessel is terminated. The connector 13 of the shaft 11 is positioned outside the blood vessel for the operation of the shaft 11 and the inflow / outflow of fluid. The hub 31 connected to the proximal end of the wire 14 is also located outside the blood vessel. As the fluid flows into the second lumen 22 from the second port 24, the posture of the balloon 12 is changed from the contracted posture to the inflated posture. As shown in FIG. 3, the balloon 12 in the inflated posture is bent so as to push the wire 14 outward.

  When the balloon 12 is expanded, the wire 14 located outside the balloon 12 is brought into contact with the atheroma (or plaque). The calcified and hardened atheroma (or plaque) is easily expanded by forming a cut when the wire 14 is brought into contact therewith. Further, when the wire 14 is brought into contact with the atheroma (or plaque), the balloon 12 is prevented from being displaced from the atheroma (or plaque).

  In a state where the balloon 12 is in an inflated posture, a drug that suppresses restenosis is injected from the syringe connected to the hub 31 into the flow path 32 of the wire 14. Examples of the drug include paclitaxel and its analogs, rapamycin and its analogs, β-lapachone and its analogs, biological vitamin D and its analogs, sirolimus, tacrolimus and the like. The injected medicine is released from the flow path 32 to the outside of the balloon 12 in the inflated posture through the through hole 33. Thereby, a chemical | medical agent is apply | coated to the periphery of the location where the wire 14 contact | abutted in atheroma (or plaque). The flow path 32 of the wire 14 may be filled with a medicine in advance before the balloon catheter 10 is inserted into the blood vessel.

  The balloon 12 expands the stenosis region and applies the medicine, and then the fluid flows out from the second lumen 22 to change the posture of the balloon 12 from the inflated posture to the deflated posture. For example, when the proximal end is pulled back, the wire 14 that has been pushed and bent by the balloon 12 is pulled and stretched again as shown in FIG. The balloon catheter 10 in this state is withdrawn from the blood vessel.

[Operational effects of this embodiment]
As described above, according to the balloon catheter 10 according to the present embodiment, the drug is applied to the inner wall of the blood vessel expanded by the balloon 12 through the flow path 32 and the through hole 33 of the wire 14, so that the blood vessel is re-applied. Stenosis is suppressed.

  In addition, since the plurality of through holes 33 are arranged in the wire 14 so as to be separated from each other in the axial direction 101, the medicine is applied over a wide range of blood vessels.

  Further, since the through-hole 33 is provided at a position outside the balloon 13 in the inflated posture and facing outward in the radial direction of the shaft 11, the inner wall of the blood vessel and the through-hole 33 face each other, and the through-hole 33. The drug released from is applied directly to the inner wall of the blood vessel.

  In addition, since the hub 31 to which a syringe can be connected is provided at the second end of the wire 14, the syringe can be used and the medicine can flow into the flow path 32 of the wire 14.

[Modification]
The balloon catheter 10 described above may further include an outer layer shaft 15 that covers the outside of the shaft 11 and the wire 14 as shown in FIG. The outer layer shaft 15 is configured such that the shaft 11 and the wire 14 can be accommodated in the internal space, and the wire 14 can slide in the self-recommended direction 101 in the internal space. The outer layer shaft 15 is a known member such as a metal, an alloy, or plastic. The tip of the outer layer shaft 15 does not overlap with the balloon 12. The proximal end of the outer layer shaft 15 does not overlap with the connector 13. The outer layer shaft 15 does not need to be provided from the balloon 12 to the connector 13, and may have a length in the axial direction 10 that is sufficiently shorter than the dimension between the balloon 12 and the connector 13. The outer layer shaft 15 prevents the shaft 11 and the wire 14 from being separated apart in the process of inserting the balloon catheter 10 into the blood vessel.

  In the embodiment described above, one wire 14 is provided on the balloon catheter 10, but a plurality of wires 14 may be provided. Moreover, the one wire 14 may be arrange | positioned so that the circumference | surroundings of the balloon 12 may be wound in a spiral shape.

DESCRIPTION OF SYMBOLS 10 ... Balloon catheter 11 ... Shaft 12 ... Balloon 13 ... Connector 14 ... Wire rod 22 ... 2nd lumen (1st flow path)
31 ... Hub 32 ... Flow path (second flow path)
33 ... Through hole

Claims (4)

A shaft that is inserted into the blood vessel from the distal end side and has a first channel through which fluid can flow;
A balloon which is provided on the tip side of the shaft and is inflated and deflated by fluid flowing into and out of the internal space through the first flow path;
A connector provided on the base end side of the shaft;
Extending along the outer surface of the balloon and the shaft, the first end is fixed to the distal end side from the balloon, and the second end extends toward the connector,
The wire rod is a balloon catheter having a second flow path through which a fluid can flow and a through-hole provided in the peripheral wall on the first end side and continuing to the second flow path.   The balloon catheter according to claim 1, wherein the plurality of through-holes are spaced apart from each other in the axial direction of the wire.   3. The balloon catheter according to claim 1, wherein in a state where the balloon is inflated, the through hole is provided at a position outside the balloon and facing outward in the radial direction of the shaft. The balloon catheter according to any one of claims 1 to 3, wherein a hub to which a syringe can be connected is provided at the second end of the wire.

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