JP5671228B2 - Balloon catheter - Google Patents

Description

  The present invention relates to a balloon catheter used for treating a stenosis in a living organ.

  For example, in the treatment of myocardial infarction and angina pectoris, a method of expanding the lesion (stenosis) of the coronary artery with a balloon catheter is used, and other blood vessels, bile ducts, trachea, esophagus, urethra, other organs, etc. The improvement of the constriction formed in the living organ may be performed in the same manner. The balloon catheter is generally configured to include a long shaft and a balloon that is provided on the distal end side of the shaft and expands in the radial direction, and a stenosis portion in the body is formed by inserting a preceding guide wire. Sent to.

  Patent Document 1 discloses a stent delivery including a stent on a balloon on the distal end side of an inner catheter (catheter main body), and an outer catheter provided as a protective sheath during insertion of the stent so as to be movable on the outer surface of the inner catheter. A balloon catheter is described.

  In the configuration described in Patent Document 1, ports are formed in the inner catheter and the outer catheter, respectively, so that the proximal end side of the guide wire is led out from the inner catheter, and these are aligned. In this case, the port of the outer catheter is connected to a slit cut to the foremost end of the outer catheter, thereby ensuring the movement of the outer catheter with the guide wire inserted. Therefore, when the outer catheter is moved with respect to the inner catheter, the guide wire may be pushed into the slit and fixed.

  Therefore, Patent Document 2 discloses a configuration for maintaining the alignment state of each port of the outer catheter and the inner catheter by the holding means and preventing the guide wire from being fixed as described above.

EP 0505686 Specification Japanese Patent Laid-Open No. 11-9696

  By the way, when the balloon catheter is inserted into the body and sent to the stenosis part, first, a high-rigidity penetration catheter for passage through the stenosis part is inserted along the guide wire, and then the stenosis part is expanded to some extent. A procedure may be performed in which the balloon catheter is replaced and sent to the stenosis. In this case, since it is necessary to prepare a penetrating catheter and a balloon catheter separately, the cost increases due to the increase in the number of devices and the procedure becomes complicated, and the procedure time tends to be further extended.

  Therefore, it is conceivable to use the balloon catheter as an inner catheter (catheter body) and to integrally use the penetrating catheter as an outer catheter (sheath).

  However, in the case of the configuration described in Patent Document 1, the outer catheter is formed with the slit up to its most advanced position, that is, the outer catheter is not given any penetrability of the stenosis and is hard. It is necessary to prepare a penetrating catheter separately for the stenosis. Furthermore, there is a possibility that the movement of the outer catheter may not be performed smoothly due to the insertion of the guide wire into the slit, and it is difficult to use the outer catheter as a penetrating catheter.

  In the case of the configuration described in Patent Document 2, the guide wire lead-out port is completely aligned and integrated between the inner catheter and the outer catheter, and it is difficult to smoothly move the outer catheter relative to the inner catheter. Therefore, it is difficult to use the outer catheter as a penetrating catheter. Moreover, the point which uses an outer catheter as a penetration catheter is not considered, and it is necessary to prepare a penetration catheter separately for a hard stenosis part after all.

  The present invention has been made in view of such conventional problems, and provides a balloon catheter that can be easily penetrated even in a hard stenosis, and can be easily operated and shorten the operation time. The purpose is to do.

The balloon catheter according to the present invention is applied via a shaft provided with a hub to which a pressure applying device can be attached on the proximal end side, and an expansion lumen provided in the vicinity of the distal end of the shaft and formed in the shaft. A balloon that is expanded by pressure from the pressure applying device, a distal opening on the distal end side of the balloon formed in the shaft, and a proximal opening on the proximal end side of the balloon and on the distal end side of the hub A balloon catheter having a catheter body having a guide wire lumen through which a guide wire is inserted, which slides on the outer surface of the shaft and moves relative to the catheter body in the axial direction. And a guide wire lug when the sheath is moved with respect to the catheter body in the middle of the sheath. The guide wire passes through the inside and outside of the sheath so that the guide wire can pass at a position overlapping the proximal end side opening of the men, and an opening that is long in the axial direction is provided, and the guide wire lumen extends from the distal end of the balloon. The axial distance from the proximal end opening to the proximal end of the sheath to the proximal end of the opening is less than or equal to the axial distance from the distal end of the sheath to the proximal end of the balloon. direction distance state, and are axial distance below the opening provided in the sheath, the outer circumferential surface of the shaft is exposed when the sheath is advanced into the distal end side of the catheter body, the sheath position marker that displays the moving position is characterized that you have provided for.

According to such a configuration, a balloon is provided in the vicinity of the distal end of the shaft, a catheter body provided with a proximal-side opening for guiding the guide wire in the middle of the guide wire lumen, and sliding on the outer surface of the shaft, A guide that is movable relative to the catheter body in the axial direction and that has a sheath provided with an opening overlapping the proximal opening, and that has passed through the proximal opening and the opening. The sheath can be smoothly advanced and retracted while preventing the wire and the edge of the opening from contacting each other. Further, the axial distance from the distal end of the balloon to the proximal end opening of the guide wire lumen is equal to or less than the axial distance from the most distal end of the sheath to the proximal end of the opening, and from the distal end of the balloon to the balloon Since the axial distance to the proximal end of the catheter is less than or equal to the axial distance of the opening provided in the sheath, the distal end side of the catheter body including the balloon can be reliably covered with the sheath, and the balloon can be securely It can also be exposed and expanded. For this reason, for example, a penetrating catheter or the like for penetrating a hard stenosis part is not separately prepared, and even a hard stenosis part can be surely penetrated by a sheath. Since it can be expanded, the operability is improved and the procedure becomes easy, the procedure time can be shortened, and the number of devices can be reduced. In addition, a position marker is provided on the outer peripheral surface of the shaft so as to be exposed when the sheath is advanced toward the distal end side of the catheter body and to display the movement position of the sheath. The advance / retreat position can be easily grasped, and the operability is further improved.

  In this case, an X-ray opaque marker that can be visually recognized by X-rays is provided in the vicinity of the most distal end of the sheath, or contrast-enhanced particles may be kneaded in the vicinity of the most distal end of the sheath. Thus, the position of the distal end of the sheath can be surely visually confirmed by X-ray imaging, and the operability can be further improved.

  The axial distance from the most distal end of the catheter body to the proximal end side opening of the guide wire lumen is not more than the axial distance from the most distal end of the sheath to the proximal end portion of the opening, and If the axial distance from the most distal end of the catheter body to the proximal end of the balloon is equal to or less than the axial distance of the opening provided in the sheath, the distal end side of the catheter body is more reliably covered by the sheath. In addition, the balloon can be reliably exposed and expanded.

  In addition, when the sheath has an excessive advance prevention mechanism that regulates the advance limit of the sheath, when the sheath is advanced relative to the catheter body, the sheath is prevented from being excessively advanced.

  The over advance prevention mechanism connects the hub provided on the proximal end side of the shaft and a sheath side hub provided on the proximal end side of the sheath, and has a length corresponding to the movement range of the sheath. If the flexible member is set to include a flexible member, excessive advance of the sheath can be reliably prevented by the flexible member.

  The over-advance prevention mechanism is provided on the proximal end side of the sheath and has a diameter-expanded stopper, and the stopper is movably accommodated, and is set to a length corresponding to the movement range of the sheath. Providing a protrusion that contacts the stopper on the side and including a cylindrical body fixed to the shaft, the contact between the stopper and the protrusion reliably prevents excessive advancement of the sheath. be able to.

  In this case, the outer surface of the cylindrical body and the sheath side hub provided on the proximal end side of the sheath may be engaged with each other so as to be movable in the axial direction and non-rotatable with each other. If it does so, the phase shift of a sheath and a catheter main body can be prevented, and the phase of the base end side opening part which guide | leads out a guide wire, and an opening part can be matched reliably.

  Note that a sheath-side hub having a port through which liquid can be fed may be provided on the proximal end side of the sheath between the inner surface of the sheath and the outer surface of the shaft. As a result, for example, physiological saline or the like can be easily flushed into the gap space between the sheath and the shaft, and the air that has entered the gap space is extracted to prevent the entry of blood or the like from the opening. be able to.

  According to the present invention, a balloon is provided in the vicinity of the distal end of the shaft, and a catheter main body provided with a proximal end opening for guiding the guide wire in the middle of the guide wire lumen; and a catheter main body sliding on the outer surface of the shaft. And a guide wire that has passed through the proximal end side opening and the opening by providing a sheath that is relatively movable in the axial direction and provided with an opening that overlaps the proximal end opening. The sheath can be smoothly advanced and retracted while preventing contact with the edge of the opening.

  Further, the axial distance from the distal end of the balloon to the proximal end opening of the guide wire lumen is equal to or less than the axial distance from the most distal end of the sheath to the proximal end of the opening, and from the distal end of the balloon to the balloon Since the axial distance to the proximal end of the catheter is less than or equal to the axial distance of the opening provided in the sheath, the distal end side of the catheter body including the balloon can be reliably covered with the sheath, and the balloon can be securely It can also be exposed and expanded. For this reason, for example, a penetrating catheter or the like for penetrating a hard stenosis part is not separately prepared, and even a hard stenosis part can be surely penetrated by a sheath. Since it can be expanded, the operability is improved and the procedure becomes easy, the procedure time can be shortened, and the number of devices can be reduced.

1 is an overall configuration diagram of a balloon catheter according to an embodiment of the present invention. It is a whole block diagram which shows the state which advanced the sheath from the state shown in FIG. 1, and covered the folded balloon with this sheath. It is side surface sectional drawing of the balloon catheter in the state shown in FIG. It is side surface sectional drawing of the balloon catheter in the state shown in FIG. It is the partially abbreviated plan view which expanded the opening part formed in the sheath, and its peripheral part. It is a partially omitted side sectional view showing a modification of the setting position of the sheath advance limit. It is a partially-omitted side sectional view showing an installation example of an X-ray opaque marker on the distal end side of the sheath. FIG. 8A is a partially omitted side sectional view showing an example of installation of the groove for removing the division of the sheath on the outer peripheral surface of the sheath body, and FIG. 8B is a sectional view taken along the line VIIIB-VIIIB in FIG. 8A. is there. It is a partially omitted side cross-sectional view according to a modification of the sheath over-advance prevention mechanism. FIG. 10 is a partially omitted side cross-sectional view in a state where the sheath is advanced from the state shown in FIG. 9. It is sectional drawing which follows the XI-XI line in FIG.

  Hereinafter, a preferred embodiment of a balloon catheter according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is an overall configuration diagram of a balloon catheter 10 according to an embodiment of the present invention, and shows a state in which a sheath 14 disposed on the outer peripheral side of a catheter body 12 is retracted and a balloon 16 is exposed and expanded. ing. FIG. 2 is an overall configuration diagram showing a state in which the sheath 14 is advanced from the state shown in FIG. 1 and the folded balloon 16 is covered with the sheath 14. 3 is a side sectional view of the balloon catheter 10 in the state shown in FIG. 1, and FIG. 4 is a side sectional view of the balloon catheter 10 in the state shown in FIG.

  In the balloon catheter 10 according to the present embodiment, a thin and long catheter body 12 and a sheath 14 are inserted into a living organ, for example, a coronary artery, and a balloon 16 provided near the distal end thereof is expanded at a stenosis (lesion). This is a so-called PTCA (Percutaneous Transluminal Coronary Angioplasty) dilatation catheter that spreads and treats the stenosis. The present invention also relates to a catheter other than such a PTCA dilatation catheter, for example, a catheter for improving a lesion formed in a living organ such as another blood vessel, bile duct, trachea, esophagus, urethra, and other organs. Applicable.

  As shown in FIGS. 1 and 2, the balloon catheter 10 is a small and long catheter main body (inner catheter) 12, and is slidably fitted on the outer peripheral side of the catheter main body 12, so that the catheter And a sheath (outer catheter) 14 that is movable relative to the main body 12 in the axial direction. The sheath 14 functions as a penetrating catheter for reliably penetrating the hard stenosis by covering the distal end side of the catheter body 12, and is retracted after the stenosis penetrates to expose and expand the balloon 16. be able to.

  The catheter body 12 includes a long and thin shaft 18, a distal tip 20 fixed to the tip of the shaft 18, a balloon 16 provided on the proximal end side of the distal tip 20, and a proximal end side of the shaft 18. And a hub 22 provided in the vehicle. A proximal end opening 26 through which the proximal end side of the guide wire 24 is led out is provided in the middle of the shaft 18 slightly toward the distal end side. That is, the balloon catheter 10 is of a type called a rapid exchange type. Hereinafter, for easy understanding, the right side (hub 22 side) of the shaft 18 in FIGS. 1 and 2 is the “base end (rear end)” side, and the left side of the shaft 18 (the distal tip 20 and the balloon 16 side) is “tip”. "Side.

  As shown in FIGS. 1 to 4, the shaft 18 supplies a contrast medium or the like as an expansion fluid for the balloon 16 and an inner tube (guide wire tube) 28 that forms a wire lumen 28 a through which the guide wire 24 is inserted. This is a concentric double tube composed of an outer tube 30 formed between the outer lumen 30a and an expansion lumen 30a.

  The inner tube 28 has a distal end positioned substantially at the center inside the distal tip 20, extends through the balloon 16 and the outer tube 30, and has a proximal end formed at the intermediate portion of the outer tube 30. The portion 26 is liquid-tightly joined. Therefore, the guide wire 24 inserted with the distal end opening 20a of the distal tip 20 as the inlet is inserted through the wire lumen 28a of the inner tube 28 from the distal end side to the proximal end side, and the proximal end opening serving as the outlet is inserted. 26.

  The outer tube 30 extends from the rear end of the balloon 16 to the tip of the hub 22 (see FIG. 3), and a portion from the tip to the proximal opening 26 forms an expansion lumen 30a with the inner tube 28. The part from the base end side opening part 26 to the hub 22 is a single pipe. The outer tube 30 is capable of feeding an expansion fluid pumped from a pressure applying device such as an indeflator (not shown) attached via a luer taper 22 a provided on the hub 22 to the balloon 16.

  The inner tube 28 has, for example, an outer diameter of about 0.1 to 1.0 mm, preferably about 0.3 to 0.7 mm, a thickness of about 10 to 150 μm, preferably about 20 to 100 μm, and a long length. The tube has a length of about 100 to 2000 mm, preferably about 150 to 1500 mm, and may have different outer diameters and inner diameters on the distal end side and the proximal end side. The outer tube 30 has, for example, an outer diameter of about 0.3 to 3.0 mm, preferably about 0.5 to 1.5 mm, a thickness of about 10 to 150 μm, preferably about 20 to 100 μm, and a length. Is about 300 to 2000 mm, preferably about 700 to 1600 mm, and may have different outer diameters and inner diameters on the distal end side and the proximal end side.

  The inner tube 28 and the outer tube 30 can be inserted into the living organ such as a blood vessel smoothly while the operator grasps and operates the proximal end side. A structure having flexibility and moderate strength (stiffness, rigidity) is preferable. Therefore, the inner tube 28 and the outer tube 30 are, for example, polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these). It may be formed of a polymer material such as polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture thereof, or a multilayer tube of the above two or more polymer materials.

  The balloon 16 can be folded and expanded by a change in internal pressure, and as shown in FIG. 3, a cylindrical portion that expands into a cylindrical shape (cylindrical shape) by an expansion fluid injected into the inside through the expansion lumen 30a. 16a, a distal end tapered portion 16b that gradually decreases in diameter on the distal end side of the cylindrical portion 16a, and a proximal end tapered portion 16c that gradually decreases in diameter on the proximal end side of the cylindrical portion 16a.

  The balloon 16 is a non-expanded cylindrical portion provided on the distal end side of the distal tapered portion 16b, which is liquid-tightly joined to the outer peripheral surface of the inner tube 28, and is provided on the proximal end side of the proximal tapered portion 16c. The cylindrical portion that is the expansion portion is fixed to the shaft 18 by being liquid-tightly joined to the distal end portion of the outer tube 30. An inner diameter of the cylindrical portion on the distal end side substantially matches the outer diameter of the inner tube 28, and an outer diameter of the cylindrical portion on the proximal end side substantially matches the outer diameter of the outer tube 30. The balloon 16 and the inner tube 28 (outer tube 30) may be fixed in a liquid-tight manner, and may be bonded by, for example, adhesion or heat fusion.

  The balloon 16 has a size when expanded, for example, the outer diameter of the cylindrical portion 16a is about 1 to 6 mm, preferably about 1 to 5 mm, and the length is about 5 to 50 mm, preferably about 5 to 40 mm. . Further, the outer diameter of the cylindrical portion which is the non-expanded portion on the distal end side is about 0.5 to 1.5 mm, preferably about 0.6 to 1.3 mm, and is substantially the same as the outer diameter of the distal tip 20. The length is about 1 to 5 mm, preferably about 1 to 2.0 mm. The outer diameter of the cylindrical portion which is the non-expanded portion on the proximal end side is about 0.5 to 1.6 mm, preferably about 0.7 to 1.5 mm, and the length is about 1 to 5 mm, preferably 2 to 4 mm. Degree. Furthermore, the length of the distal end taper portion 16b and the proximal end taper portion 16c is about 1 to 10 mm, preferably about 3 to 7 mm.

  Such a balloon 16 is required to have an appropriate flexibility as in the case of the inner tube 28 and the outer tube 30 and to have a strength that can surely spread the narrowed portion. For example, it may be the same as that of the inner tube 28 and the outer tube 30 exemplified above, and other materials may be used.

  As shown in FIG. 3, X formed on the outer peripheral surface of the inner tube 28 located in the balloon 16 by an X-ray (radiation) opaque material (radiation opaque material) made of gold, platinum, or the like. A line-opaque marker 31 can also be provided. If it does so, the position of the balloon 16 can be reliably visually recognized by X-ray imaging in the living body, and operability can be improved.

  As shown in FIG. 3, the distal tip 20 is a short tube whose outer diameter is substantially the same as the cylindrical portion on the distal end side of the balloon 16 and whose inner diameter is substantially the same as the outer diameter of the inner tube 28. For example, the length in the axial direction is about 0.5 to 10 mm. The distal tip 20 is externally fitted and liquid-tightly joined to the distal end portion of the inner tube 28 and protrudes more distally than the distal opening portion of the wire lumen 28a. As can be understood from FIG. 3, the distal end side opening 20 a of the distal tip 20 communicates with the wire lumen 28 a of the inner tube 28 and serves as an inlet of the guide wire 24.

  Such a tip 20 is preferably configured more flexibly than the inner tube 28 (outer tube 30) by appropriately setting the material and shape thereof. For example, polyolefin (for example, polyethylene, polypropylene, polybutene, Polymer materials such as ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, etc. Alternatively, a mixture thereof, or a multilayer tube of the above two or more polymer materials may be used.

  In the state other than the state where the periphery of the distal tip 20 is completely covered with the sheath 14 (see FIG. 4), that is, the exposed state (see FIG. 3 and FIG. 6), In addition to flexibly proceeding through the curved portion and the concavo-convex portion, the penetration of the balloon catheter 10 is led through the narrowed portion (lesioned portion).

  As shown in FIGS. 1 to 4, the sheath 14 is disposed on the outer peripheral side of the catheter body 12, slides on the outer surface of the outer tube 30, and can move relative to the catheter body 12 in the axial direction. It is a simple tube.

  The sheath 14 includes a thin and long sheath main body 32 provided with a tapered portion 32a leading the smooth insertion in the living organ at the distal end, and a sheath side hub 34 provided on the proximal end side of the sheath main body 32. With. In the middle of the sheath body 32, an opening (slit) 36 for allowing the guide wire 24 led out from the proximal end opening 26 of the shaft 18 to pass outside is formed. The opening 36 is a long hole extending in the axial direction through the inside and outside of the sheath body 32, and is formed in the middle of the sheath body 32 as described above. It is continuous in the direction (see FIGS. 3 and 5). With this opening 36, the guide wire 24 from the proximal end opening 26 can be reliably led out of the sheath body 32.

  In this embodiment, the sheath 14 is moved from the position where the balloon 16 can be completely exposed as shown in FIGS. 1 and 3 (retraction limit) from the catheter body 12 (balloon as shown in FIGS. 2 and 4). 16 and the tip 20) can be slid on the shaft 18 to a position where it can completely cover (advance limit). Therefore, in order to ensure that the guide wire 24 is led out within the movement range of the sheath 14 from the advance limit to the retreat limit, the opening 36 has a shaft 36 in which the axial front end 36a and the rear end 36b are always within the movement range. 18 is formed so as to overlap with the base end side opening 26 (see FIGS. 3 to 5).

  That is, as shown in FIGS. 3 and 4, the axial distance (distance L1 + distance L2) from the most distal end of the catheter body 12 (the distal end of the distal tip 20) to the proximal end side opening 26 of the wire lumen 28a is: The axial direction distance (distance L3 + distance L4) from the foremost end of the sheath 14 (sheath body 32) to the rear end 36b of the opening 36 is set (L1 + L2 ≦ L3 + L4). Further, the axial distance L1 from the most distal end of the catheter body 12 (the distal end of the distal tip 20) to the proximal end of the balloon 16 is set to be equal to or less than the axial distance L4 of the opening 36 of the sheath 14 (L1 ≦ L4). ).

  Further, as shown in FIG. 5, the width W of the opening 36 (a dimension orthogonal to the axial direction in plan view) is preferably set smaller than the diameter D of the shaft 18 (outer tube 30). Then, when the sheath body 32 and the shaft 18 are bent in the vicinity of the opening 36 during operation of the balloon catheter 10 or the like, the shaft 18 can be prevented from jumping out of the opening 36. For example, the width W of the opening 36 and the diameter D of the outer tube 30 may be set in a range of 0.2D ≦ W ≦ 0.8D.

  In such a balloon catheter 10, in order to prevent the sheath 14 from moving excessively beyond the moving range and the leading end 36a and the trailing end 36b of the opening 36 and the guide wire 24 coming into contact with each other, the sheath 14 14 over-movement prevention mechanisms may be provided.

  As shown in FIGS. 3 and 4, in the state where the sheath 14 has moved to the retracted position (see FIGS. 1 and 3), the excessive movement prevention mechanism has the base end of the sheath side hub 32 at the tip of the hub 22. In the structure that fits into the tapered portion 22b and stops by contacting the flange portion 22c (over-retreat prevention mechanism) and the sheath 14 has moved to the advanced position (see FIGS. 2 and 4), the hub 22 A wire 38 coupled between the sheath side hub 34 is stretched, and the sheath 14 has a structure that prevents further advancement of the sheath 14 (over advance prevention mechanism). The wire 38 is a flexible member such as a thread, and is stretched to the maximum with the hub 22 and the sheath-side hub 34 separated to the maximum (the advance limit of the sheath 14 shown in FIGS. 2 and 4). , That is, approximately the same length as the movement range of the sheath 14 (distance L1 or distance L4), and thereby the advance limit of the sheath 14 can be defined.

  As shown in FIG. 4, a plurality of movement position markers 39 arranged in the axial direction at predetermined intervals may be provided on the outer peripheral surface of the outer tube 30 constituting the shaft 18. The movement position marker 39 is inserted into the body during use and displays the positional relationship between the most distal position of the sheath body 32 and the catheter body 12 that cannot be directly recognized. For example, the advancement limit of the sheath 14 (FIG. 4). (See FIG. 3), or a position where the balloon 16 is completely exposed from the sheath 14 (see FIG. 3). The moving position marker 39 may be provided by any method as long as it can be visually recognized, such as a method of marking the outer peripheral surface of the outer tube 30 with ink, a method of scraping the outer peripheral surface of the outer tube 30 or a method of melting with heat. .

  As shown in FIGS. 3 and 4, the sheath-side hub 32 includes a proximal-side luer taper 40 fitted to the tapered portion 22 b of the hub 22, and an oblique direction with respect to the axial direction of the sheath 14 from a substantially central portion. And a port 42 having a luer taper 42a extending in the Y direction.

  The flow path 42 b from the port 42 communicates with the space A between the inner surface of the sheath body 32 and the outer surface of the shaft 18 through the side hole 44 of the sheath body 32. Accordingly, the port 42 can function as a priming port, and physiological saline or the like can be easily flushed into the space A between the sheath body 32 and the shaft 18. Intrusion of blood or the like from 36 can be prevented. The port 42 can also be used for spraying medicine from the opening 36.

  Since the sheath body 32 slides on the shaft 18, the inner diameter thereof needs to be set larger than the outer diameter of the shaft 18. For example, the inner diameter is about 0.3 to 3.0 mm, preferably A tube having a thickness of about 0.5 to 1.5 mm, a thickness of about 10 to 300 μm, preferably about 30 to 200 μm, a length of about 300 to 2000 mm, preferably about 700 to 1600 mm, and the inner surface of the tube Preferably, the outer surface has a uniform diameter, and the outer surface has the tapered portion 32a at the tip.

  Such a sheath main body 32 is preferably configured with higher rigidity than the catheter main body 12 (shaft 18) by appropriately setting the material, thickness, etc., for example, polyolefin (for example, polyethylene, polypropylene, Polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluorine resin, etc. It may be formed of a molecular material or a mixture thereof, or a multilayer tube of the above two or more polymer materials. Here, the configuration in which the sheath main body 32 is higher in rigidity than the catheter main body 12 is not only in the case where the sheath main body 32 is simply made of a hard material, but in other cases, for example, by increasing the thickness of the sheath main body 32, the rigidity is increased. An elevated structure or the like may be used. Further, in order to ensure the slidability between the sheath body 32 and the shaft 18 more reliably, one or both of the sliding surfaces of both members may be coated with a fluorine-based resin such as PTFE.

  The advance limit in the movement range of the sheath 14 may be other than the position where the catheter main body 12, that is, the distal tip 20 can be completely covered as described above. As shown in FIG. In a certain state, at least a part (tip side portion) of the tip 20 may be set to protrude from the most distal end of the sheath body 32 (tip of the taper portion 32a).

  As can be seen from FIG. 4 and the like, the outer diameter of the sheath body 32 is considerably larger than that of the guide wire 24, so that the distal tip 20 protrudes from the distal end side of the sheath body 32 as shown in FIG. With such a configuration, the distal end portion of the balloon catheter 10 has a tapered shape that gradually expands to the outer diameter of the guide wire 24, the outer diameter of the distal tip 20 and the outer diameter of the sheath 14 (tapered portion 32a). It becomes. Thereby, the level | step difference in the front-end | tip part of the balloon catheter 10 is reduced as much as possible, the movement to a constriction part becomes smoother, and operativity improves. At this time, since the tapered portion 32a is formed at the distal end of the sheath 14 having the largest diameter at the most distal end portion of the balloon catheter 10, the tapered shape from the guide wire 24 to the sheath 14 is configured more smoothly. Therefore, the operability and penetrability can be further improved.

  In the case of the configuration shown in FIG. 6, for example, the axial distance (distance L1a + distance L2) from the proximal end of the protruding portion of the distal tip 20 from the sheath 14 to the proximal opening 26 of the wire lumen 28a is the sheath 14. It is set to an axial distance (distance L3 + distance L4) from the most distal end of the sheath body 32 to the rear end 36b of the opening 36 (L1a + L2 ≦ L3 + L4), and the balloon 16 extends from the proximal end of the protruding portion of the distal tip 20. The axial distance L1a to the proximal end of the sheath 14 may be set to be equal to or less than the axial distance L4 of the opening 36 of the sheath 14 (L1a ≦ L4).

  Next, the operation of the balloon catheter 10 according to this embodiment configured as described above will be described.

  First, the form of the stenosis part (lesion part) which generate | occur | produced in the coronary artery etc. is specified by the intravascular imaging method or the intravascular ultrasonic diagnostic method. Next, the guide wire 24 is introduced into the blood vessel percutaneously from the thigh or the like by, for example, the Seldinger method, and the guide wire 24 is inserted into the inner tube 28 from the distal opening 20a of the distal tip 20. The balloon catheter 10 is inserted into the coronary artery while the wire lumen 28a is inserted and led out to the proximal opening 26.

  Then, under X-ray fluoroscopy, the guide wire 24 is advanced to the intended stenosis, passed through the stenosis, and placed, and the balloon catheter 10 is advanced along the guide wire 24 into the coronary artery. Then, since the leading edge of the balloon catheter 10 reaches the stenosis part and passes (penetrates) and the balloon 16 is located in the stenosis part, an expansion fluid (for example, a contrast medium) enters the expansion lumen 30a from the hub 22 side. ) Is expanded, the balloon 16 is expanded and the stenosis is expanded, and a predetermined treatment can be performed.

  Thus, when the balloon catheter 10 is inserted into the body along the guide wire 24, the sheath 14 is set to the advance limit as shown in FIG. Since the sheath body 32 made of this functions as a penetrating catheter, even a hard stenosis can be easily and reliably penetrated. After the penetration, the balloon 14 can be exposed and expanded at the narrowed portion by retracting the sheath 14. Moreover, by forming the tapered portion 32a at the distal end of the sheath 14 having the largest diameter at the most distal portion of the balloon catheter 10 (see FIG. 4), the penetrability by the sheath 14 can be further improved. The operability of the balloon catheter 10 and the insertion property in the body are further improved.

  On the other hand, when the uneven shape of the route to the target stenosis is complicated and hard, it may be necessary to advance the balloon catheter 10 flexibly along the uneven shape. Therefore, in such a case, the sheath 14 is appropriately retracted to expose the distal end side of the relatively flexible catheter body 12, and the distal tip 20 is advanced as the most advanced, so that the uneven shape can be flexibly dealt with. However, the balloon catheter 10 can easily reach the target stenosis, and if the stenosis is hard, the sheath 14 is advanced to the position shown in FIGS. In addition, the narrowed portion can be surely penetrated.

  As described above, the balloon catheter 10 according to the present embodiment includes the catheter body 12 provided with the balloon 16 on the distal end side and provided with the proximal-side opening portion 26 that leads the guide wire 24 in the middle of the shaft 18, and the catheter body. And a sheath 14 provided with an opening 36 that is movable in the axial direction with respect to the catheter body 12 on the outer peripheral side of 12 and that overlaps with the proximal-side opening 26.

  Accordingly, the sheath 14 can be smoothly advanced and retracted while preventing the guide wire 24 that has passed through the proximal opening 26 and the opening 36 from contacting the sheath body 32 (the edge of the opening 36). . As a result, the distal end side of the catheter body 12 can be covered with the sheath 14 and the balloon 16 can be exposed and expanded, so there is no need to prepare a penetrating catheter or the like for penetrating a hard stenosis. . That is, according to the balloon catheter 10, the sheath 14 can surely penetrate even a hard stenosis, and the balloon 16 can be quickly expanded at the stenosis after the penetration. Thus, the procedure becomes easy, the procedure time can be shortened, and the number of devices can be reduced. Further, since the opening portion 36 of the sheath 14 is formed at a position offset by a distance L3 from the most distal end of the sheath main body 32, the most distal end (tapered portion) of the sheath main body 32 is formed as in the configuration of Patent Document 1 above. There is no low strength part (slit etc.) in 32a), and a high penetration force can be obtained.

  In this case, as shown in FIGS. 3 and 4, the axial distance (distance L1 + distance L2) from the most distal end of the catheter body 12 to the proximal end side opening 26 is from the most distal end of the sheath 14 (sheath body 32). It is set to be equal to or less than the axial distance (distance L3 + distance L4) to the rear end 36b of the opening 36 (L1 + L2 ≦ L3 + L4), and the axial distance L1 from the most distal end of the catheter body 12 to the proximal end of the balloon 16 is The axial distance L4 or less of the opening 36 of the sheath 14 is set (L1 ≦ L4). On the other hand, in the case where the leading end of the catheter body 12 is not completely covered, as shown in FIG. 6, the proximal end opening of the wire lumen 28a from the proximal end of the protruding portion from the sheath 14 of the distal tip 20 is provided. The axial distance up to 26 (distance L1a + distance L2) is set to be equal to or less than the axial distance (distance L3 + distance L4) from the most distal end of the sheath 14 (sheath body 32) to the rear end 36b of the opening 36 (L1a + L2 ≦ L3 + L4), the axial distance L1a from the proximal end of the protruding portion of the distal tip 20 to the proximal end of the balloon 16 is set to be equal to or smaller than the axial distance L4 of the opening 36 of the sheath 14 (L1a ≦ L4).

  Accordingly, the sheath 14 can be more reliably covered with the sheath 14 up to the most distal end of the catheter body 12, the balloon 16 can be reliably exposed and expanded, and the opening 36 provided in the middle of the sheath 14. It is more reliably prevented that the edge portion of the guide wire 24 and the guide wire 24 come into strong contact with each other.

  The movement range of the sheath 14 can achieve both the penetration function of the sheath 14 as a penetration catheter and the expansion of the balloon 16 if at least the balloon 16 can be completely covered and the balloon 16 can be completely exposed. it can. Therefore, as shown in FIG. 6, the axial distance (distance L1b + distance L2) from the distal end of the balloon 16 to the proximal end side opening 26 of the wire lumen 28a opens from the most distal end of the sheath 14 (sheath body 32). The axial distance to the rear end 36b of the portion 36 (distance L3 + distance L4) is set (L1b + L2 ≦ L3 + L4), and the axial distance L1b of the balloon 16 is set to be equal to or less than the axial distance L4 of the opening 36 of the sheath 14. (L1b ≦ L4). Needless to say, when the tip 20 is omitted, the distance L1b is substantially the same as the distance L1.

  In the balloon catheter 10, the amount of protrusion of the catheter body 12 from the most distal end of the sheath 14 can be appropriately changed by appropriately setting the position of the sheath 14 near the retreat limit or an intermediate position between the advance limit and the retreat limit. it can. Thereby, the distal end side of the balloon catheter 10 can be configured flexibly, the intermediate portion can be configured with intermediate rigidity, and the proximal end side provided with the hub 22 and the sheath side hub 32 can be configured with high rigidity. Since the rigidity of each part can be appropriately changed, the operability can be further improved. In general, a balloon catheter is required to have a flexibility that can flexibly cope with the uneven shape of a living organ on the distal end side, and a proximal end side that is appropriate for smoothly inserting a long balloon catheter into the living organ. This is because a structure having strength is preferable. As described above, in the present embodiment, the sheath 14 having higher rigidity than the catheter body 12 is appropriately advanced and retracted, so that the rigidity balance of the catheter body 12 can be varied and appropriately adjusted. The shaft balance can be easily optimized according to the condition of the body.

  In particular, when the distal end tip 20 that is more flexible than the shaft 18 is provided on the distal end side of the shaft 18 like the balloon catheter 10, the distal tip 20 can be covered with high rigidity when penetrating through a hard constriction. It is effective to use the sheath 14. Furthermore, in the state where the sheath 14 is retracted to expose the distal tip 20 and the like, the flexibility of the catheter body 12 functions effectively, so that the concave and convex shape and the bent part in the body can be smoothly advanced, Since the end side is given high rigidity by the sheath 14, its operability is also improved.

  Further, as in the present embodiment, in the balloon catheter 10 called a so-called rapid exchange type, the proximal end side opening portion 26 for leading the guide wire 24 is formed in the middle of the shaft 18. The rigidity in the vicinity of the portion 26 tends to decrease. Therefore, by providing the sheath 14, the reduced rigidity of the shaft 18 can be compensated and the strength around the take-out portion of the guide wire 24 can be increased.

  In the balloon catheter 10, by providing a movement position marker 39 that allows the movement position of the sheath 14 to be easily recognized from the outside (see FIG. 4), the position of the sheath main body 32 can be easily grasped at hand. The rigidity of the entire catheter 10 can be changed more easily. Furthermore, since the position of the sheath 14 can be easily grasped, it is possible to reliably prevent the sheath 14 from being excessively advanced and the guide wire 24 biting into the front end 36a and the rear end 36b of the opening 36.

  As shown in FIG. 7, an X-ray opaque marker 46 substantially similar to the X-ray opaque marker 31 described above can be provided on the distal end side of the sheath 14. Reference numeral 47 in FIG. 7 is a cylindrical support member for fixing the X-ray opaque marker 46 to the outer peripheral surface of the sheath 14. Of course, the X-ray opaque member 46 is not used without using the support member 47. The transmission marker 46 can be directly fixed to the outer peripheral surface of the sheath 14 or embedded.

  By providing the X-ray opaque marker 46, the distal end position of the sheath body 32 can be surely visually confirmed by X-ray imaging in the living body, and the operability can be further improved. In particular, when the sheath 14 is advanced to the advance limit and the balloon catheter 10 is inserted into the body, the distal end position or the vicinity thereof can be surely grasped by the radiopaque marker 46, which is effective. It is. In addition, by providing the sheath 14 with the X-ray opaque marker 46, the X-ray opaque marker 31 on the shaft 18 (catheter body 12) side can be omitted depending on the use conditions of the balloon catheter 10, and the structure is simplified and the cost is reduced. Reduction is possible.

  Note that the radiopaque marker 46 is preferably installed at a position where the distance L5 from the most distal end of the sheath 14, for example, is within 10 mm, for example, in order to display the distal end position of the sheath body 32 more appropriately. In addition to providing the radiopaque marker 46, for example, contrast-enhancing particles or the like may be mixed into the material (resin) on the distal end side including the tapered portion 32 a of the sheath body 32.

  As shown in FIGS. 8A and 8B, a pair of V-shaped grooves 48, 48, for example, may be formed on the outer peripheral surface of the sheath body 32 of the sheath 14 so as to extend in the axial direction. As a result, when the sheath 14 is not necessary due to the state of the stenosis, etc., the operator tears the sheath 14 from the opened balloon catheter 10 along the groove 48 in the longitudinal direction, and easily removes the long sheath 14. And can be removed quickly. When the sheath 14 is configured to be split in this manner, the material of the sheath 14 may be polyethylene or polypropylene, for example.

  As described above, it is also effective to provide the wire 38 between the hub 22 and the sheath side hub 32 as a mechanism for preventing the sheath 14 from excessively advancing. It should be noted that the mechanism for preventing the sheath 14 from excessively moving forward may of course have a configuration other than the wire 38 and the movement position marker 39.

  FIG. 9 is a partially omitted side sectional view according to a modified example of the mechanism for preventing excessive advancement of the sheath 14 and shows a proximal end portion of the balloon catheter 10 in a state in which the sheath 14 is retracted. 10 is a partially omitted side cross-sectional view in a state where the sheath 14 is advanced from the state shown in FIG. 9, and FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG. 9 to 11, the same reference numerals as those shown in FIGS. 1 to 8 indicate the same or similar configurations, and thus the detailed description is omitted as they exhibit the same or similar functions and effects. To do.

  As shown in FIGS. 9 and 10, in this modification, the sheath 14 includes a sheath-side hub 50 instead of the sheath-side hub 32, and the catheter body 12 includes a hub 52 instead of the hub 22.

  The hub 52 includes a cylindrical body 54 that protrudes toward the distal end side of the flange portion 22c. The cylindrical body 54 is a rigid body having a diameter larger than that of the outer tube 30, and a pair of diameter-reducing portions (projections) 54 a provided at the distal end side opening through which the outer tube 30 passes and a pair of upper and lower positions on the outer peripheral surface are provided. Engagement protrusions 54b and 54b (see FIG. 11) extending in the axial direction. 9 and 10, the cylindrical body 54 protects the shaft 18 and the sheath body 32 on the proximal end side of the balloon catheter 10, and bends at a portion where a force is easily applied by manual operation. It functions as a kink protector for preventing the above.

  The sheath-side hub 50 has a cylindrical space 56 in which the cylindrical body 54 is formed so as to be able to advance and retract between the sheath main body 32 inserted through the inside of the sheath-side hub 50. A pair of engaging groove portions 56a and 56a are formed in which the mating convex portion 54b can engage and slide.

  Therefore, by providing the stopper 58 having an enlarged diameter at the proximal end portion of the sheath main body 32 extending into the cylindrical body 54, the sheath 14 has its advance limit due to the abutting action of the stopper 58 and the reduced diameter portion 54a. It is defined (see FIG. 10), and over advance is reliably prevented. Further, the sheath 14 and the catheter main body 12 are not rotatable with each other due to the engaging action of the engaging convex portion 54b and the engaging groove portion 56a. For this reason, when the balloon catheter 10 is used, the sheath 14 is prevented from rotating with respect to the catheter main body 12 and out of phase with each other, and the proximal end side opening portion 26 of the shaft 18 and the opening portion 36 of the sheath 14 are prevented. The phase can be reliably maintained, and the guide wire 24 can be reliably led out.

  The present invention is not limited to the above-described embodiment, and it is needless to say that various configurations and processes can be adopted without departing from the gist of the present invention.

  For example, the tip 20 may be omitted, and in that case, a configuration in which the most distal position of the inner tube 28 and the most distal position of the cylindrical portion that is a non-expanded portion on the distal end side of the balloon 16 are matched, A configuration in which the most distal position of the inner tube 28 protrudes somewhat from the most distal position of the cylindrical portion is preferable.

DESCRIPTION OF SYMBOLS 10 ... Balloon catheter 12 ... Catheter main body 14 ... Sheath 16 ... Balloon 18 ... Shaft 22, 52 ... Hub 24 ... Guide wire 26 ... Proximal opening 28 ... Inner tube 28a ... Wire lumen 30 ... Outer tube 30a ... For expansion Lumen 32 ... Sheath body 34, 50 ... Sheath side hub 36 ... Opening 38 ... Wire 39 ... Moving position marker 42 ... Port 54 ... Cylindrical body

Claims (7)

A shaft provided on the proximal side with a hub to which a pressure applying device can be attached;
A balloon that is provided near the tip of the shaft and expands by pressure from the pressure applying device applied via an expansion lumen formed in the shaft;
A guide wire lumen formed in the shaft and through which a guide wire is inserted through a distal end opening on the distal end side of the balloon and a proximal end opening on the proximal end side of the balloon and on the distal end side of the hub. When,
A balloon catheter comprising a catheter body having
A sheath that slides on the outer surface of the shaft and is movable relative to the catheter body in the axial direction;
In the middle of the sheath, when the sheath is moved with respect to the catheter body, the guide wire can pass inside and outside the sheath so that the guide wire can pass at a position overlapping the proximal end opening of the guide wire lumen. Penetrating, provided with an axially long opening,
The axial distance from the distal end of the balloon to the proximal end side opening of the guide wire lumen is not more than the axial distance from the most distal end of the sheath to the proximal end of the opening, and the balloon axial distance from the distal end to the proximal end of the balloon state, and are axial distance below the opening provided in the sheath,
An outer peripheral surface of the shaft is exposed when the sheath is advanced into the distal end side of the catheter body, a balloon catheter characterized that you have a position marker that displays the moving position of the sheath is provided. The balloon catheter according to claim 1,
The axial distance from the most distal end of the catheter body to the proximal end side opening of the guide wire lumen is not more than the axial distance from the most distal end of the sheath to the proximal end portion of the opening, and The balloon catheter characterized in that the axial distance from the most distal end of the catheter body to the proximal end of the balloon is equal to or less than the axial distance of the opening provided in the sheath. The balloon catheter according to claim 1 or 2 ,
A balloon catheter having an over-advance prevention mechanism for defining an advance limit of the sheath. The balloon catheter according to claim 3 ,
The over advance prevention mechanism connects the hub provided on the proximal end side of the shaft and a sheath side hub provided on the proximal end side of the sheath, and has a length corresponding to the movement range of the sheath. A balloon catheter comprising a flexible member set in the above. The balloon catheter according to claim 3 ,
The excessive advance prevention mechanism is provided on the proximal end side of the sheath, and has a diameter-expanded stopper;
A cylindrical body fixed to the shaft, wherein the stopper is movably accommodated, is set to a length corresponding to the movement range of the sheath, and is provided with a protrusion that contacts the stopper on the distal end side.
A balloon catheter. The balloon catheter according to claim 5 ,
A balloon catheter characterized in that an outer surface of the cylindrical body and a sheath side hub provided on the proximal end side of the sheath are engaged with each other so as to be movable in the axial direction and non-rotatable with each other. The balloon catheter according to any one of claims 1 to 6 ,
A balloon catheter having a sheath-side hub having a port capable of feeding a liquid between an inner surface of the sheath and an outer surface of the shaft is provided on a proximal end side of the sheath.

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