JP2018134299A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter that can be easily checked by an echo guide method.SOLUTION: A balloon catheter 10 includes a shaft 11, a distal end chip 25 provided on the distal side of the shaft 11, a balloon 12 provided to the shaft 11, which can change its posture between an expanded posture and a contracted posture, and a recess 30 formed on a peripheral surface 31 of at least one of the distal end chip 25 and an inner shaft 14. The reflection of an ultrasonic wave is diffused by the recess 30 formed on the peripheral surface 31 of the distal end chip 25 or the inner shaft 14, which allows the position of the balloon 12 to be checked easily in an image by a reflection wave.SELECTED DRAWING: Figure 4

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 stenotic part 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 stenotic part, and a guiding catheter or a sheath introducer is inserted into the blood vessel. insert. 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.

  As a method for confirming the position of a balloon catheter inserted into a blood vessel, for example, a method is known in which a marker that can be confirmed by X-rays is embedded in a balloon catheter, and the position of the marker is confirmed in an image irradiated with X-rays. Yes. In addition, a method is known that uses an echo guide method of irradiating ultrasonic waves and confirming the position of the balloon catheter from the obtained reflected wave image (see Patent Document 1).

JP 2004-283289 A

  However, in the image in the echo guide method, there is a problem that the outer shape of the balloon catheter does not necessarily appear clearly, and it is difficult to confirm the position and state of the balloon.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a balloon catheter that is easy to confirm in the echo guide method.

  (1) A balloon catheter according to the present invention is provided on a shaft having a double lumen structure, a distal end tip provided on the distal side of the shaft, and the shaft, and can be changed in an expanded posture and a contracted posture. A balloon, and a recess formed on at least one peripheral surface of the shaft or the tip.

  The reflection of the ultrasonic wave is diffused by the concave portion formed on the distal tip or the peripheral surface of the shaft, so that the position of the balloon or the like can be easily confirmed in the image by the echo guide method.

  (2) Preferably, the recesses are positioned with an interval in the axial direction of the shaft. This makes it easier to confirm the position of the shaft in the axial direction.

  (3) Preferably, the concave portion is located in the vicinity of the balloon in the shaft. Thereby, it becomes easy to confirm the position of the balloon in the image by the echo guide method.

  (4) The concave portion is in a region where the balloon is located on the outer side of the inner shaft among the outer shaft and the inner shaft constituting the double lumen.

  When the balloon outside the recess of the inner shaft is in a contracted position, the folded balloon covers the outside of the recess, so that a part of the ultrasonic wave is reflected by the folded balloon and attenuated by the folded balloon Ultrasound reaches the recess. As a result, the outer shape of the recess is less likely to appear in the image by the echo guide method. On the other hand, when the balloon outside the concave portion of the inner shaft is in the expanded posture, the reflection of ultrasonic waves by the balloon is relatively small, and the ultrasonic waves reaching the concave portion are relatively large. As a result, the outer shape of the recess is likely to appear in the image by the echo guide method. The posture of the balloon can be confirmed by an image based on the difference in appearance of the outer shape of the recess.

  (5) Preferably, the concave portion is located at a position where the outer diameter of the balloon is maximum and the axial position of the shaft overlap in the inner shaft. Thereby, it becomes easy to confirm the position that becomes the maximum outer diameter of the balloon, which is a portion that presses the blood vessel during vascular dilation.

  The balloon catheter according to the present invention is easy to confirm in the echo guide method.

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. 4A is an external view of the region 26 of the shaft 11 in the balloon 12, and FIG. 4B is a longitudinal sectional view of the region 26 of the shaft 11 in the balloon 12. FIG. 5A is an external view showing a recess 32 according to a modification, and FIG. 5B is an external view showing a recess 33 according to the 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, the balloon catheter 10 includes a shaft 11 (an inner shaft 14 and an outer shaft 15) having a double lumen structure, a balloon 12 provided on the distal end side of the shaft 11, and a shaft 11 in the vicinity. And a connector 13 provided on the rear end side.

  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 center portion along the axial direction 101 of the shaft 11 by the inner shaft 14, and the second lumen 22 is formed by the outer shaft 15 located outside thereof. The material of the inner shaft 14 and the outer shaft 15 is preferably a biocompatible material. Specifically, polyurethane, polyethylene, polyester, polypropylene, polyether block amide, polyamide, polytetrafluoroethylene, polyvinylidene fluoride, etc. Can be mentioned.

  The first lumen 21 is formed from the proximal end to the distal end of the inner shaft 14. The inner diameter of the first lumen 21 is set to a diameter capable of inserting a guide wire. That is, the balloon catheter 10 is an over-the-wire type. The second lumen 22 is a space through which a fluid such as a contrast medium or physiological saline or air can flow. The second lumen 22 is formed from the proximal end of the outer shaft 15 to the vicinity of the distal end of the balloon 12. The length of the shaft 11 in the axial direction 101 is appropriately set in consideration of the length from a catheter insertion part such as a human limb or coronary artery to the affected part. The structure of the shaft 11 is merely an example, and the shaft 11 may be another known structure such as a rapid exchange type.

  A balloon 12 is provided on the distal end side of the outer shaft 15. The balloon 12 has a bag shape made of a film that does not allow blood to pass in the thickness direction. The internal space of the bag-shaped balloon 12 is in communication with the second lumen 22. That is, although not appearing in each drawing, the second lumen 22 is open inside the balloon 12. Through this opening, the fluid flowing through the second lumen 22 can flow into and out of the balloon 12. 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 for the film is preferably a biocompatible material, and 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 (which coincides with the axial direction 101 in FIGS. 1 to 3), and both ends are reduced in diameter to a tapered shape. is there. 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. 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.

  As shown in FIG. 2, a tip tip 25 is coaxially provided at the distal end of the inner shaft 14. The tip of the tip tip 25 protrudes to the distal end side from the balloon 12. The tip 25 is made of a material that is more flexible than the inner shaft 14. The shaft 11 is inserted into the blood vessel from the distal end side where the tip 25 is provided. When the tip 25 is bent following the curvature of the blood vessel, the shaft 11 is likely to follow and bend. The tip 25 is a part of the shaft 11.

  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 axial direction 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 axial direction 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 FIG. 3, a recess 30 (see FIG. 4) is formed on the outer surface of the tip 25. Further, in the inner shaft 15, a recess 30 (see FIG. 4) is also formed on the peripheral surface of the region 26 where the balloon 12 is located outside. The region 26 overlaps with the region X having the maximum outer diameter in the balloon 12 in the expanded posture in the axial direction 101. In FIG. 3, the description of the recess 30 is omitted.

  As shown in FIG. 4A, the recess 30 has a groove shape that is recessed from the peripheral surface 31 of the inner shaft 14, and extends in a direction orthogonal to the axial direction 101 so as to make one round of the peripheral surface 31. It is. A plurality of the recesses 30 are arranged at intervals in the axial direction 101 in the tip tip 25 of the shaft 11 and the region 26 of the inner shaft 14. The dimension in which the recess 30 is recessed from the peripheral surface 31 of the inner shaft 14, the dimension along the axial direction 101 of the recess 30, the interval between the adjacent recesses 30, and the like are the outer diameter of the inner shaft 14 and the tip 25, It is determined as appropriate in consideration of the ease of diffusion of ultrasonic waves. As shown in FIG. 4 (B), the cross-sectional shape of the recess 30 is a quadrangle, and the peripheral surface is a plane. However, the cross-sectional shape of the recess 30 is not limited to a quadrangle, and may be a triangle or a dome shape. Also good. Further, depending on the method of forming the recess 30, each corner of the recess 30 may be rounded and may be a curved surface continuous with the peripheral surface 31.

  The recess 30 is formed by, for example, press-fitting an appropriately heated shaft 11 into the mold and cooling it using a mold that surrounds the inner shaft 14 and that can be brazed to the inner shaft 14. can do. Of course, the recess 30 may be formed by other methods such as cutting the peripheral surface 31 of the shaft 11. The same applies to the method of forming the recess 30 in the tip 25.

[Operational effects of this embodiment]
According to the balloon catheter 10, since the reflection of the ultrasonic wave is diffused by the concave portion 30 formed on the peripheral surface 31 of the inner shaft 14, the position of the balloon 12 can be easily confirmed in the image by the echo guide method. In particular, since there is a recess 30 in the region 26 of the inner shaft 14 where the outer diameter of the balloon 12 is the maximum and the position in the axial direction 101 overlaps, It becomes easy to confirm the position that becomes the maximum outer diameter.

  Further, when the balloon 12 outside the region 26 of the inner shaft 14 is in a contracted posture, the folded balloon 12 covers the outside of the recess 30, so that a part of the ultrasonic wave is reflected by the folded balloon 12, The ultrasonic wave attenuated by the folded balloon 12 reaches the recess 30. As a result, the outer shape of the recess 30 in the region 26 is less likely to appear in the image. On the other hand, when the balloon 12 outside the region 26 of the inner shaft 14 is in the expanded posture, the ultrasonic wave reaches the concave portion 30 after passing through one film of the expanded balloon 12, so Is relatively smaller than the contracted posture, and the ultrasonic wave reaching the recess 30 is relatively larger than the contracted posture. As a result, the outer shape of the recess 30 in the region 26 tends to appear in the image by the echo guide method. The posture of the balloon 12 can be confirmed by an image by the echo guide method by the difference in appearance of the outer shape of the recess 30 in the region 26.

  In addition, since the concave portion 30 is formed in the tip 25 on the distal side of the balloon 12, the outer shape of the concave 30 of the tip 25 appears in the image by the echo guide method regardless of the posture of the balloon 12. It becomes easy to confirm the position near the balloon 12. In particular, since the most advanced position of the balloon catheter 10 can be grasped, it is useful for a procedure using the balloon catheter 10.

[Modification]
In the above-described embodiment, the recess 30 has a ring shape that makes one round around the peripheral surface 31 of the tip 25 or the inner shaft 14 around the axial direction 101. However, as shown in FIG. Instead, the recess 32 extending in a spiral shape around the axial direction 101 on the peripheral surface 31 of the tip 25 or the inner shaft 14 may be formed. Further, unlike the concave portion 30 and the concave portion 32, the tip surface 25 or the peripheral surface 31 of the inner shaft 14 does not need to continuously extend around the axial direction 101 for one or more rounds. For example, as shown in FIG. As illustrated, a plurality of recesses 33 extending in a direction intersecting the axial direction 101 by less than one circumference around the axial direction 101 may be formed at intervals in the axial direction 101. In this case, the recesses 33 may or may not be arranged in a line in the direction intersecting the axial direction 101.

  Further, in the above embodiment, the recess 30 is formed in the tip tip 25 and the region 26 of the inner shaft 11, but the recess 30 is also formed in the region proximal to the balloon 12 in the outer shaft 15. Also good. Further, in place of the tip 25 and the region 26, the inner shaft 14 and the outer shaft 15 may be formed with a recess 30 only in a region proximal to the balloon 12, or on the distal side of the balloon 12. The concave portion 30 may be formed only in the tip tip 25 of this.

DESCRIPTION OF SYMBOLS 10 ... Balloon catheter 11 ... Shaft 12 ... Balloon 14 ... Inner shaft 15 ... Outer shaft 25 ... Tip tip 30, 32, 33 ... Recessed part

Claims (5)

A double-lumen shaft,
A tip provided on the distal side of the shaft;
A balloon provided on the shaft and capable of changing its posture into an inflated posture and a deflated posture;
A balloon catheter comprising at least a recess formed on one peripheral surface of the shaft or the tip.   The balloon catheter according to claim 1, wherein the recesses are located at an interval in the axial direction of the shaft.   The balloon catheter according to claim 1, wherein the concave portion is positioned in the vicinity of the balloon in the shaft.   The balloon catheter according to any one of claims 1 to 3, wherein the concave portion is in a region where the balloon is located outside of the inner shaft of the outer shaft and the inner shaft constituting the double lumen. 5. The balloon catheter according to claim 4, wherein the concave portion is located at a position where the outer diameter of the balloon is maximized on the inner shaft and a position in the axial direction of the shaft overlap.

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