JP2009232882A - Dilation catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an dilation catheter, in which a liquid medicine is only administered to a desired region and reducing the catheter diameter is possible. <P>SOLUTION: The dilation catheter has a tube body 2 having a first lumen 3 and a second lumen 4 formed therein, and a shrinkable or foldable expanding body 6 provided at the distal end of the tube body 2. This expanding body 6 has a multiple structure consisting of at least the two layers of inner and outer layers 8 and 7 mutually in a close contact with each other. The first lumen 3 communicates with the interior of the inner layer 8. The outer layer 7 is provided with a liquid medicine release function to release the liquid medicine outward after its supply from the layer 7's side contacting the inner layer 8; and the inner and outer layers 8 and 7 are separated from each other by the pressure of the fluid flowing from the second lumen 4 to make this separated space between these two layers communicate with the second lumen 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dilatation catheter used for treating a stenosis occurring in a body cavity such as a blood vessel.

  Conventionally, as a means of treating a stenosis in a blood vessel, a percutaneous transluminal coronary angioplasty is performed by expanding the stenosis using a catheter with an expansion body to improve blood flow. : PTCA). As such a catheter with an expansion body, for example, Patent Document 1 discloses an expansion body that can be contracted or folded to expand a stenosis, and a liquid-permeable permeation solution provided so as to cover the outside of the expansion body. A balloon catheter comprising a membrane is described. This balloon catheter has a drug solution administration function that is independent of the function of expanding the stenosis by the expansion body. Therefore, independent of the operation of expanding the expansion body, the drug solution can be administered from the permeable membrane at a desired site, and the stenosis can be treated more effectively.

However, since the permeable membrane is always permeable, the chemical solution inside the permeable membrane is not completely isolated from the blood flow, so that the chemical solution leaks out and the chemical solution can be administered only at the desired site. There was a problem that it was difficult. In addition, since a gap is provided between the permeable membrane and the expansion body, there is a problem that the diameter when lapping is caused by contraction or folding becomes large.
Japanese Unexamined Patent Publication No. 7-136283

  The present invention has been made in order to solve the problems associated with the above-described prior art, and can be used to administer a drug solution only at a desired site and can reduce the diameter of the expansion body during lapping. The purpose is to provide.

  The object is achieved by the inventions described in (1) to (7) below.

  (1) A dilatation catheter for expanding a stenosis in a body cavity, wherein a tube body in which a first lumen and a second lumen are formed, and an inner layer and an outer layer that are provided at the distal end of the tube body and are in close contact with each other An expansion body capable of contraction or folding, and the first lumen communicates with the inner layer, and the outer layer is supplied from the side in contact with the inner layer. A release function for releasing the drug to be discharged to the outside, fluid pressure from the second lumen causes separation between the inner layer and the outer layer, and the two layers communicate with the second lumen. Dilatation catheter.

  (2) The dilatation catheter according to (1), wherein the outer layer is made of an elastomer material.

  (3) The dilatation catheter according to (1) or (2), wherein the inner layer has higher rigidity than the outer layer.

  (4) The expansion body is provided with an adhesive layer that partially adheres between the inner layer and the outer layer and maintains adhesion even in the peeling. The dilatation catheter as described in any one of these.

  (5) The dilatation catheter according to (4), wherein the adhesive layer is formed of a polymer alloy of a material constituting the inner layer and the outer layer.

  (6) The dilatation catheter according to any one of (1) to (5), wherein the release function is at least one thin portion provided in the outer layer.

  (7) The second lumen is formed in an annular cross section, an outer peripheral surface of the outer layer is fixed to an outer peripheral surface of the second lumen, and an inner peripheral surface of the inner layer is an inner periphery of the second lumen. The dilatation catheter according to any one of (1) to (6), wherein the dilatation catheter is fixed to a surface.

  According to the invention described in (1) above, the outer layer is provided with a release function for releasing the drug to the outside, the inner layer and the outer layer are formed in close contact with each other, and the inner layer and the outer layer are formed by fluid pressure from the second lumen. Since the two layers are separated and the two layers communicate with the second lumen, the drug solution does not leak from the outer layer until the inner layer and the outer layer are peeled off, and the drug solution is administered only at a desired site. Can do. Moreover, since the inner layer and the outer layer are formed in close contact with each other, the diameter of the expansion body at the time of wrapping can be reduced.

  Further, according to the invention described in (2) above, since the outer layer is made of an elastomer material, the outer layer easily expands, and peeling between the inner layer and the outer layer can be favorably caused.

  Further, according to the invention described in (3) above, the inner layer has higher rigidity than the outer layer, so that even when pressure is applied between the inner layer and the outer layer, the state in which the constricted portion is expanded is maintained. Cheap.

  Further, according to the invention described in the above (4), the expansion body is provided with the adhesive layer that partially adheres between the inner layer and the outer layer and maintains the adhesion even at the time of peeling. It is possible to suppress the spread, achieve an appropriate expanded state of the outer layer satisfactorily, and secure a chemical liquid flow path.

  Further, according to the invention described in (5) above, since the adhesive layer is formed by a polymer alloy of the material constituting the inner layer and the outer layer, it firmly adheres to both the inner layer and the outer layer, and between the inner layer and the outer layer. Even when peels, the adhesive state can be maintained at the site of the adhesive layer.

  Further, according to the invention described in (6) above, since the release function is at least one thin portion provided in the outer layer, the release of the chemical solution can be suppressed until the thin portion penetrates, and the chemical solution is applied only at a desired site. Can be administered.

  According to the invention described in (7) above, the outer peripheral surface of the outer layer is fixed to the outer peripheral surface of the second lumen, and the inner peripheral surface of the inner layer is fixed to the inner peripheral surface of the second lumen. Therefore, peeling between the inner layer and the outer layer can be favorably caused by the pressure of the chemical liquid supplied to the second lumen.

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

<First Embodiment>
1 is a side view of the dilatation catheter according to the first embodiment of the present invention, FIG. 2 is an enlarged longitudinal sectional view of the distal end portion of the catheter shown in FIG. 1, and FIG. 3 is a proximal end portion of the catheter shown in FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. 2, FIG. 5 is an enlarged cross-sectional view taken along line V-V in FIG. 2, and FIG. It is an expanded transverse sectional view which follows the -VI line.

  As shown in FIG. 1, the dilatation catheter 1 according to this embodiment has an OTW (over the wire) structure in which a guide wire 17 is inserted from the hand to the distal end, and is fixed to the tube body 2 and the proximal end of the tube body 2. Hub 10. As shown in FIGS. 2 to 6, the dilatation catheter 1 is provided at the distal end of the tube body 2 and the tube body 2, communicates with the first lumen 3 formed on the tube body 2, is inflatable, and It has the expansion body 6 which can be shrunk or folded. The expansion body 6 has a multilayer structure including an inner layer 8 and an outer layer 7 in close contact with each other.

  The tube body 2 includes an outer tube 21, an intermediate tube 22, and an inner tube 23.

  The outer tube 21 is a tubular body having an open front end and a rear end, and is coaxially formed on the outer side of the intermediate tube 22 as shown in FIGS. Alternatively, it has a tip in a retracted position. The constituent material of the outer tube 21 is preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-acetic acid. Polyolefins such as vinyl copolymers, ionomers, or a mixture of two or more of these, thermoplastic resins such as soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, fluororesins, silicone rubbers, latex rubbers Etc. can be used.

  The middle tube 22 is a tubular body having an open front end and a rear end, and is coaxially formed outside the inner tube 23 as shown in FIGS. It has a tip at the position.

  As the constituent material of the middle tube 22, it is preferable to use a material having a certain degree of flexibility, like the outer tube 21.

  The inner tube 23 is a tubular body having an open front end and a rear end, and as shown in FIG. 2, the front end portion is disposed so as to protrude from the outer tube 21 and the middle tube 22.

  As the constituent material of the inner tube 23, the same material as that of the outer tube 21 and the intermediate tube 22, or various metal materials such as stainless steel, stainless stretchable alloy, and Ni—Ti alloy can be used.

  The first lumen 3 is formed in an annular shape between the intermediate tube 22 and the inner tube 23, and the second lumen 4 is formed in an annular shape between the outer tube 21 and the intermediate tube 22. Has been. Furthermore, the inside of the inner tube 23 is a third lumen 5 that opens at the tip of the tube body 2.

  When the expansion body 6 is not expanded, the expansion body 6 can be contracted or folded around the outer periphery of the tube main body 2 (in the illustrated example, the inner tube 23). And the expansion body 6 expands the stenosis part X of a blood vessel, and as shown in FIG. 2 and FIG. 4, at least one part is substantially cylindrical shape so that expansion can be performed easily. It has a substantially cylindrical portion 6a having a diameter. In addition, this substantially cylindrical part 6a does not need to be a perfect cylinder, For example, polygonal prism shape may be sufficient.

  The distal end portion of the expansion body 6 is liquid-tightly fixed to the distal end portion of the inner tube 23 by an adhesive or heat fusion. Further, the base end portion of the expansion body 6 has the inner peripheral surface of the inner layer 8 fixed to the outer peripheral surface of the distal end portion of the intermediate tube 22 in the same manner, and the outer peripheral surface of the outer layer 7 is similarly connected to the inner peripheral surface of the distal end portion of the outer tube 21. It is fixed. Therefore, the outer layer 7 and the inner layer 8 are fixed to each of the outer peripheral surface and the inner peripheral surface of the second lumen 4 formed in an annular cross section, and therefore, due to the pressure of the chemical solution supplied to the second lumen 4, Peeling between the inner layer 8 and the outer layer 7 can be favorably caused. The outer layer 7 and the inner layer 8 are formed in close contact with each other. When the outer layer 7 and the inner layer 8 are separated from each other, a space communicating with the second lumen 4 is formed, and the chemical solution can be injected into the space via the second lumen 4.

  The interior of the expansion body 6 communicates with the first lumen 3, and the expansion fluid can flow through the first lumen 3. The expansion body 6 is expanded by the inflow of the expansion fluid, and is contracted or folded by discharging the inflowing expansion fluid.

  The constituent material of the inner layer 8 is preferably a crystalline material that has a high pressure resistance so that it does not burst when expanded and can be biaxially stretched with a high elastic modulus. For example, polyamide, polyethylene terephthalate, high density Polyethylene or the like can be suitably used.

  As the size of the expanded body 6, the outer diameter of the substantially cylindrical portion 6a when expanded is 1.0 to 30 mm, preferably 1.0 to 10.0 mm, and the length is 5 to 50 mm, preferably 10 -40 mm, and the entire length of the expansion body 6 is 10-70 mm, preferably 15-60 mm. In this embodiment, since the outer layer 7 is formed in close contact with the inner layer 8, the thickness and diameter of the expansion body 6 can be reduced. Thereby, the outer diameter at the time of lapping can be made small and it is excellent in the performance as a catheter.

  The outer layer 7 has a substantially cylindrical portion 7 a that constitutes a part of the substantially cylindrical portion 6 a of the expansion body 6. The outer layer 7 is provided with a plurality of thin portions 24 (release function) in a substantially cylindrical portion 7a. The thin portion 24 is formed with micro holes 25 having a predetermined depth without completely penetrating the outer layer 7 from the outer peripheral surface. In addition, the thin part 24 may be formed in the form of a groove | channel, or may be formed from the inner peripheral surface side.

  Between the outer layer 7 and the inner layer 8, a plurality of stripe-like adhesive layers 26 extending from the proximal end side to the distal end side are formed. In addition, a distal end adhesive layer 27 provided over the entire circumference is formed between the outer layer 7 and the inner layer 8 at the distal end of the expansion body 6. The adhesive layer 26 and the tip adhesive layer 27 can maintain the adhesive state between the outer layer 7 and the inner layer 8 even when the outer layer 7 and the inner layer 8 are separated. The above-described micro holes 25 are formed in a portion different from the position in contact with the adhesive layer 26 of the outer layer 7. The outer layer 7 may be directly bonded to the outer peripheral surface of the inner tube 23 instead of bonding the outer layer 7 and the inner layer 8 with the tip end bonding layer 27.

  The inner layer 8 preferably has higher rigidity than the outer layer 7 so that the state in which the narrowed portion X is expanded can be maintained even when pressure is applied between the inner layer 8 and the outer layer 7.

  The material of the outer layer 7 is preferably a flexible material that has good workability with an excimer laser, and examples thereof include polyester elastomers and polystyrene elastomers that contain an aromatic ester segment. If such a material is used, the micropore 25 can be easily formed by an excimer laser.

  The material combination of the inner layer 8 and the outer layer 7 is preferably a dissimilar material having a different melting point and structural formula, whereby the inner layer 8 and the outer layer 7 can be easily separated by applying pressure to the close contact portion. Is possible.

  The material of the adhesive layers 26 and 27 is preferably a polymer alloy of an inner layer material and an outer layer material. In this way, it is possible to firmly adhere to each of the inner layer 8 and the outer layer 7, and even when the outer layer 7 and the inner layer 8 are peeled off, adhesion between the outer layer 7 and the inner layer 8. The state can be reliably maintained. The material of the adhesive layers 26 and 27 is not particularly limited as long as it can maintain the adhesive state between the outer layer 7 and the inner layer 8 at the time of peeling, even if it is not a polymer alloy.

  Further, as the chemical liquid permeable material used for the outer layer 7, a material having micropores penetrated in advance can be used. For example, a semipermeable membrane, a nonwoven fabric, a woven fabric, a mesh, a porous membrane, or the like can be applied. Note that the thickness of the substantially cylindrical portion 7a made of these materials is such that the flexibility of the substantially cylindrical portion 7a is not impaired.

  By configuring in this way, the medicinal solution permeates only the substantially cylindrical portion 7a of the outer layer 7, so that the amount of medicinal solution released to the region other than the constricted portion X can be reduced, and the affected area can be effectively treated. In addition, when the expansion body 6 (inner layer 8) is expanded, the expansion pressure is transmitted to the drug solution, and the drug solution is vigorously pushed toward the stenosis part X, so that the drug solution can penetrate well into the stenosis part X. .

  In addition, the outer layer 7 and the inner layer 8 are not necessarily limited to those composed entirely of the same material, and a portion made of a different material may be slightly provided.

  In addition, on the outer surface of the outer layer 7 and the outer tube 21, for example, a cellulosic polymer material (hydroxypropylcellulose, etc.), a polyethylene oxide polymer material (polyethylene glycol), Maleic anhydride polymer (eg, maleic anhydride copolymer such as methyl vinyl ether maleic anhydride copolymer), acrylamide polymer (eg, methylacrylamide-glycidyl methacrylate copolymer), water-soluble nylon You may coat | cover hydrophilic (or water-soluble) polymeric substances, such as (For example, AQ-nylon P-70 by Toray Industries, Inc.). Thereby, when the outer surface of the tube main body 2 comes into contact with blood, physiological saline, or the like, the friction coefficient is reduced, lubricity is imparted, and the slidability of the tube main body 2 is further improved.

  The diameter of the micropore 25 is about 50 to 200 μm and is provided with an interval of about 500 to 1000 μm, but is not limited to these conditions. Further, the microhole 25 may be formed on the entire outer layer 7 or only a part of the outer layer 7, but when the outer layer 7 has a substantially cylindrical portion 7a, the minute hole 25 may be provided on the substantially cylindrical portion 7a. preferable. Thereby, a chemical | medical solution can be effectively administered from the position close | similar to the constriction part X. FIG.

  Moreover, such micropores 25 can be easily formed by, for example, irradiating the formed outer layer 7 with an excimer laser.

  An X-ray opaque marker 9 is wound around a predetermined location included in the expansion body 6 on the outer peripheral surface of the inner tube 23, preferably a location corresponding to the center of the substantially cylindrical portion 6a of the expansion body.

  The radiopaque marker 9 is made of a radiopaque material and is formed in a coil shape. The marker 9 may be cylindrical, for example. The radiopaque material is preferably platinum, gold, tungsten, iridium, or an alloy thereof, and more preferably platinum, gold, or a platinum-iridium alloy. By configuring with such a material, a clear contrast image can be obtained under X-ray fluoroscopy, so that the position of the substantially cylindrical portion 6a of the expansion body 6 can be easily confirmed under X-ray fluoroscopy.

  If desired, the outer tube 21, the intermediate tube 22 and the inner tube 23 are each made of stainless steel in order to prevent the catheter from being bent at the bent portion of the blood vessel and to further improve the followability of the catheter to a high degree of bending in the blood vessel. A mesh of braided wires or linear bodies made of highly rigid materials such as metals such as elastic metals, superelastic alloys, shape memory alloys, amorphous alloys, and synthetic fibers such as polyamide resins, polyester resins, and polypropylene resins You may provide the rigidity imparting body formed in the shape of a coil or a coil.

  The hub 10 includes an outer tube hub 11 having a first opening 14, an intermediate tube hub 12 having a second opening 15, and an inner tube hub 13 having a third opening 16. The outer tube hub 11, the intermediate tube hub 12, and the inner tube hub 13 are fixed in this order.

  The outer tube 21 is fixed inside the outer tube hub 11. Examples of the means for fixing include adhesion with an adhesive, thermal fusion, fixation with a fastener (not shown), and the like. The first opening 14 communicates with the second lumen 4 and functions as a chemical liquid injection port for introducing the chemical liquid between the second lumen 4 and the inner layer 8 and the outer layer 7.

  The middle tube 22 is fixed to the inside of the middle tube hub 12 in the same manner as the outer tube 21. The second opening 15 communicates with the first lumen 3, introduces an expansion fluid for expanding the expansion body 6 into the first lumen 3, and discharges the fluid from the first lumen 3. Function as a port to

  The inner tube 23 is fixed inside the inner tube hub 13 in the same manner as the outer tube 21 and the middle tube 22. The third opening 16 communicates with the third lumen 5 and functions as a guide wire port for inserting the guide wire 17 into the third lumen 5.

  As the constituent material of the outer tube hub 11, the middle tube hub 12, and the inner tube hub 13, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

  Instead of providing such a branch hub, each of the first lumen 3, the second lumen 4, and the third lumen 5 is liquid-tight, for example, a tube having a port member that forms an opening at the rear end. You may make it attach to.

  Further, the outer tube 21, the middle tube 22, and the inner tube 23 may each be provided with a reinforcing tube (not shown) for preventing the tube body 2 from being twisted or bent outside the base end portion. By installing such a tube, blockage of the first lumen 3, the second lumen 4, and the third lumen 5 due to bending or twisting of the tube body 2 is prevented.

  Examples of the reinforcing tube include tube bodies made of various resins such as cross-linked polyolefin and silicone rubber, a coil-shaped tube made of a hard material such as a metal such as stainless steel, or a combination thereof.

  Next, the action of the drug solution administration catheter according to the present embodiment will be described by taking as an example the case of treating a stenosis occurring in a coronary artery blood vessel with the catheter shown in FIGS. 7 is an enlarged longitudinal sectional view of the distal end portion of the catheter when the outer layer and the inner layer are peeled off, FIG. 8 is an enlarged transverse sectional view taken along the line VIII-VIII in FIG. 7, and FIG. It is an enlarged longitudinal cross-sectional view of the distal end portion of the catheter. 10, FIG. 11 and FIG. 12 are explanatory views showing the usage state of the catheter according to this embodiment.

  First, before treating the stenosis X of the blood vessel, the air in the expansion body 6, the first lumen 3 and the second lumen 4 is extracted as much as possible, and the expansion body 6 and the second lumen 4 are contrast medium or the like. And the inside of the first lumen 3 is replaced with a chemical solution for treating the stenosis X. At this time, the expansion body 6 is in a contracted or folded state as shown in FIG.

  Next, a sheath is placed in the patient's blood vessel by, for example, the Seldinger method, and the distal end portion of the tube body 2 in a state where the guide wire 17 is inserted into the third lumen 5 so as to protrude about 5 to 50 mm is sheathed. It is inserted into the blood vessel through the lumen. Subsequently, while viewing the position of the marker 9 under X-ray fluoroscopy and confirming the positions of the distal ends of the tube body 2 and the guide wire 17, the guide wire 17 is advanced to advance the catheter 1. Thus, the catheter 1 is made to reach the stenosis part X.

Next, in a state where the distal end portion of the tube main body 2 is positioned at the constricted portion X, a predetermined amount of a chemical solution is injected from the first opening 14 of the outer tube hub 11 at a pressure P ₁ that is equal to or higher than a predetermined value. 4 to feed the chemical. As a result, as shown in FIGS. 7 and 8, separation occurs between the outer layer 7 and the inner layer 8 at the portion where the outer layer 7 and the inner layer 8 of the expansion body 6 are in direct contact with each other because the interlayer adhesion is low. The chemical solution flows into the generated gap. At this time, since the outer layer 7 is formed of an elastomer material, the outer layer 7 easily expands and easily peels off. Note that at the distal end of the expansion body 6, the outer layer 7 and the inner layer 8 are liquid-tightly fixed by the distal end adhesive layer 27 having high interlayer adhesion over the entire circumference, so that the chemical solution flows out from the distal end. do not do. Further, since the stripe-like adhesive layer 26 having high interlayer adhesion is provided between the outer layer 7 and the inner layer 8, even when the outer layer 7 expands, the adhesion state between the outer layer 7 and the inner layer 8 is partially Maintained. Thereby, the excessive expansion of the outer layer 7 is suppressed, an appropriate expanded state of the outer layer 7 can be satisfactorily achieved, and a flow path for the chemical solution can be secured. That is, by appropriately setting the length, width, number (such as the number in the circumferential direction and the number of divisions in the extending direction) of the adhesive layer 26, a desired expanded state of the outer layer 7 according to the situation can be realized.

Thereafter, further the pressure P ₂ higher than a predetermined value by increasing the pressure of the drug solution, as shown in FIG. 9, through the weak thin portions 24 pressure strength than the surrounding, via a small hole 25 fluid Flows out into the blood vessel. Thus, the pressure P ₂ through which the thin portion 24, it is set higher than the pressure P ₁ for peeling between the outer layer 7 and the inner layer 8, can be individually controlled delamination and penetration. That is, if the thinned portion 24 of the already peeled portion penetrates before the peeling is completely completed, the outflow portion of the chemical solution may be biased. However, according to the present embodiment, the outer layer 7 and the inner layer 8 are peeled off. Since the thin-walled portion 24 can be penetrated after the process is finished, the outflow site of the chemical liquid can be made uniform. The pressure through which the thin portion 24 penetrates can be appropriately set by adjusting the size, depth, shape, and the like of the thin portion 24 (micropore 25). Incidentally, necessarily, the pressure P ₂ through which the thin portion 24 may not be set higher than the pressure P ₁ for peeling between outer 7 and inner 8. Furthermore, the outer layer 7 may be provided with a through-hole penetrating from the beginning instead of the thin-walled portion 24.

  Next, a predetermined amount of an expansion fluid such as a contrast medium is injected from the second opening 15 of the intermediate tube hub 12 using a syringe or the like, and the expansion body 6 (inner layer 8) of the expansion body 6 (inner layer 8) is injected through the first lumen 3. The expansion fluid is sent into the interior to expand the expansion body 6. As a result, as shown in FIG. 11, the drug solution leaches out to the outside through the outer layer 7 and fills in the vicinity of the stenosis part X, and further, the expansion pressure of the expansion body 6 is applied, and the stenosis part X penetrates well. To do.

  Then, when the expansion of the expansion body 6 proceeds, the expansion body 6 reaches the constriction X, and expands the constriction X as shown in FIG. At this time, the drug solution filled in the vicinity of the stenosis part X is pressed against the stenosis part X by the expansion of the expansion body 6, whereby the drug solution penetrates the stenosis part X even better.

  During this time, the control of the expansion pressure of the expansion body 6 and the control of the injection amount of the drug solution are performed independently, so that it is easy to adjust the expansion pressure and the drug solution dose to the stenosis part X as desired according to the degree of stenosis. Can be.

  The administration of the chemical solution and the expansion of the expansion body 6 may be performed by first expanding the expansion body 6 and then injecting the chemical liquid through the first opening 14 or in the reverse order. The order can be set as appropriate.

  After the constriction X is expanded, the expansion fluid is sucked and discharged from the second opening 15 so that the expansion body 6 is contracted or folded. Thereafter, the tube body 2 is removed from the blood vessel through the sheath, and the procedure is completed.

  The chemical solution may be administered when the expansion fluid is discharged. Further, the injection of the chemical solution from the opening 14 may be stopped simultaneously with the discharge of the expansion fluid.

Second Embodiment
13 is a side view of the dilatation catheter according to the second embodiment of the present invention, FIG. 14 is an enlarged longitudinal sectional view of the distal end portion of the catheter shown in FIG. 13, and FIG. 15 is a proximal end portion of the catheter shown in FIG. FIG. 16 is an enlarged cross-sectional view taken along line XVI-XVI in FIG. 14, and FIG. 17 is an enlarged cross-sectional view taken along line XVII-XVII in FIG. In addition, the same code | symbol is attached | subjected to the site | part which has the same function as 1st Embodiment, and description is abbreviate | omitted in order to avoid duplication.

  As shown in FIG. 13, the dilatation catheter 31 according to the second embodiment has an Rx (Rapid Exchange) structure in which the guide wire 17 is inserted only on the distal end side, and is fixed to the tube body 32 and the proximal end of the tube body 32. Hub 40.

  As shown in FIGS. 14 to 17, the dilatation catheter 31 is provided at the distal end of the tube body 32 and the tube body 32, communicates with a first lumen 33 formed in the tube body 32, is inflatable, and It has the expansion body 6 which can be shrunk or folded. About the structure of the expansion body 6 of the dilatation catheter 31 which concerns on 2nd Embodiment, since it is the same as 1st Embodiment, description is abbreviate | omitted.

  As in the first embodiment, the tube body 32 has a three-layer structure of a coaxial lumen including an outer tube 36, an intermediate tube 37, and an inner tube 38 at a portion connected to the expansion body 6 on the distal end side. A first lumen 33 is formed annularly between the intermediate tube 37 and the inner tube 38, and a second lumen 34 is formed annularly between the outer tube 36 and the intermediate tube 37. Yes. Furthermore, the inside of the inner tube 38 is a third lumen 35 that opens at the tip of the tube body 32.

  Further, the tube body 32 is formed with a main tube 39 in which the outer tube 36 and the intermediate tube 37 are integrated, closer to the proximal side than the portion connected to the expansion body 6, and the first lumen 33 and the second lumen 34 are arranged in parallel. It has a multi-lumen structure. An inner tube 38 is coaxially provided inside the first lumen 33, and a third lumen 35 formed inside the inner tube 38 opens laterally in the center portion in the extending direction of the main tube 39. is doing. The opening 45 functions as a guide wire port for inserting the guide wire 17 through the third lumen 35.

  On the proximal side of the main pipe 39, the first lumen 33 and the second lumen 34 are opened and fixed to the hub 40. Examples of means for fixing the main pipe 39 and the hub 40 include adhesion with an adhesive, thermal fusion, fixation with a stopper (not shown), and the like.

  As constituent materials of the outer tube 36, the intermediate tube 37, and the main tube 39, the same materials as those of the outer tube 21 and the intermediate tube 22 of the first embodiment can be used.

  As a constituent material of the inner tube 38, the same material as that of the inner tube 23 of the first embodiment can be used.

  The hub 40 has a first opening 41 and a second opening 42. The first opening 41 communicates with the second lumen 34 and functions as a chemical liquid injection port for introducing the chemical liquid between the second lumen 34 and the inner layer 8 and the outer layer 7.

  The second opening 42 communicates with the first lumen 33, and introduces an expansion fluid for expanding the expansion body 6 into the first lumen 33 and discharges it from the first lumen 33. Function as a port.

  As a constituent material of the hub 40, the same material as the hub 10 of the first embodiment can be used.

  The main tube 39 may be provided with a reinforcing tube (not shown) for preventing the tube main body 32 from being twisted or bent outside the base end portion. By installing such a tube, blockage of the first lumen 33 and the second lumen 34 due to bending or twisting of the tube body 32 is prevented.

  In addition, about the effect | action of the dilatation catheter 31 which concerns on 2nd Embodiment, since the insertion position of the guide wire 17 of the tube main body 32 differs, it is the same as that of 1st Embodiment, Therefore It abbreviate | omits description.

  The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims. For example, the present invention is not limited to application in blood vessels, and can be applied to various uses such as for ureters, bile ducts, oviducts, and hepatic ducts.

It is a side view of the dilatation catheter concerning a 1st embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view of a distal end portion of the catheter shown in FIG. FIG. 2 is an enlarged longitudinal sectional view of a proximal end portion of the catheter shown in FIG. 1. FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. 2. FIG. 5 is an enlarged cross-sectional view taken along line VV in FIG. 2. FIG. 3 is an enlarged cross-sectional view taken along line VI-VI in FIG. 2. It is an expanded longitudinal cross-sectional view of the front-end | tip part of a catheter when an outer layer and an inner layer peel. FIG. 8 is an enlarged cross-sectional view taken along line VIII-VIII in FIG. 7. It is an expanded longitudinal cross-sectional view of the front-end | tip part of a catheter when a thin part penetrates. It is explanatory drawing which shows the use condition of the catheter which concerns on this embodiment. It is explanatory drawing which shows the use condition of the catheter which concerns on this embodiment. It is explanatory drawing which shows the use condition of the catheter which concerns on this embodiment. It is a side view of the dilatation catheter concerning a 2nd embodiment of the present invention. FIG. 14 is an enlarged longitudinal sectional view of the distal end portion of the catheter shown in FIG. 13. FIG. 14 is an enlarged longitudinal sectional view of a proximal end portion of the catheter shown in FIG. 13. FIG. 15 is an enlarged cross-sectional view taken along line XVI-XVI in FIG. 14. FIG. 15 is an enlarged cross-sectional view taken along line XVII-XVII in FIG. 14.

Explanation of symbols

1,31 dilatation catheter,
2,32 tube body,
3,33 The first lumen,
4,34 The second lumen,
5,35 The third lumen,
6 Extensions,
7 outer layer,
8 Inner layer,
17 Guide wire,
24 Thin part,
26 adhesive layer,
X Stenosis.

Claims (7)

A dilatation catheter for dilating a stenosis in a body cavity,
A tube body in which a first lumen and a second lumen are formed;
The tube body is provided at the tip of the tube body, and has a multilayer structure of at least two layers including an inner layer and an outer layer that are in close contact with each other, and has an expandable body that can be contracted or folded.
The first lumen communicates with the inside of the inner layer, and the outer layer is provided with a release function for releasing the medicine supplied from the side in contact with the inner layer to the outside, and the fluid pressure from the second lumen An expansion catheter, wherein an inner layer and an outer layer are separated from each other, and the two layers communicate with the second lumen.   The dilatation catheter according to claim 1, wherein the outer layer is made of an elastomer material.   The dilatation catheter according to claim 1 or 2, wherein the inner layer has higher rigidity than the outer layer.   The expansion body is provided with an adhesive layer that partially adheres between the inner layer and the outer layer and maintains adhesion even in the peeling. The dilatation catheter as described.   5. The dilatation catheter according to claim 4, wherein the adhesive layer is formed of a polymer alloy of a material constituting the inner layer and the outer layer.   The dilatation catheter according to any one of claims 1 to 5, wherein the discharge function is at least one thin portion provided in the outer layer.   The second lumen is formed in an annular cross section, the outer peripheral surface of the outer layer is fixed to the outer peripheral surface of the second lumen, and the inner peripheral surface of the inner layer is fixed to the inner peripheral surface of the second lumen. The dilatation catheter according to any one of claims 1 to 6, wherein

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