JP2012196294A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter which quickly stops bleeding and eludes chemicals, while ensuring sufficient blood flow in the blood vessel.SOLUTION: An expanding/contracting member 16 which is constituted of a plurality of wires 24 is attached to the distal end of a catheter body 12. An operating tube 14 is pushed/pulled to/from the catheter body 12 to deform the expanding/contracting member 16 so as to be expanded or contracted. A membrane 18 for medical treatment is attached to the outer peripheral surface of the expanding/contracting member 16 to constitute the catheter 10. When the expanding/contracting member 16 is deformed to increase or reduce the diameter in the blood vessel 34, to press an injured area 36 for stopping bleeding with the membrane 18 for medical treatment, or a chemical is eluded after expanding a narrowed area, sufficient blood flow can be ensured through the inside of the expanding/contracting member 16.

Description

  The present invention relates to a catheter used for blood vessel hemostasis and drug elution.

  2. Description of the Related Art Conventionally, in the field of clinical medicine, a catheter or a guide wire is inserted into a lesion site of a blood vessel to perform various treatments, examinations, treatments, and the like. For example, when performing PTCA (percutaneous coronary angioplasty), which is known as a treatment method for myocardial infarction and angina pectoris, treatment and treatment are performed by inserting a catheter or guide wire into the stenosis of the coronary artery of the heart. .

  By the way, when the treatment or treatment using the catheter or the guide wire as described above is performed, the blood vessel may be damaged by the catheter or the guide wire inserted into the blood vessel and may bleed. In such a case, it is necessary to immediately stop bleeding at the damaged site of the blood vessel. In particular, when such blood vessel damage occurs during cardiovascular treatment with PTCA or the like, hemostasis treatment of the damaged portion of the blood vessel must be performed very urgently.

  Therefore, conventionally, a method of compressing and hemostasing a damaged site of a blood vessel by inserting a balloon catheter into the blood vessel and expanding the balloon, or inserting a stent graft into the blood vessel and placing it in an expanded state. Is generally done.

  However, when a hemostatic treatment using a balloon catheter is performed, blood flow in the blood vessel is blocked by expansion of the balloon. Therefore, if the time required for the hemostasis treatment becomes long, there is a risk that a serious aftereffect may occur due to ischemia. On the other hand, when a hemostasis treatment using a stent graft is performed, a problem may occur in the course after the hemostasis treatment because the stent graft is permanently placed in the blood vessel.

  Japanese Patent No. 3744571 (Patent Document 1) proposes a balloon catheter in which a through hole is provided in the peripheral wall portion on the proximal end side of the balloon attachment site of the catheter. In this balloon catheter, the blood flow before and after the balloon in the expanded state is secured by using the distal end opening of the catheter, the lumen, and the through hole in the peripheral wall as a blood flow path. . However, in the catheter described in Patent Document 1, the lumen of the catheter has a small diameter, and the distal end opening and the through hole of the catheter have extremely small opening areas. There was concern that it would be difficult to ensure a stable supply.

Japanese Patent No. 3744571

  An object of the present invention is to provide a catheter having a novel structure capable of quickly and safely carrying out a hemostasis treatment while stably securing a sufficient blood flow in a blood vessel.

  A first aspect of the present invention uses an expansion / contraction member that is configured by a plurality of wires and expands and deforms in a radial direction by compressive input in the axial direction, and attaches the expansion / contraction member to the distal end of the catheter body, By fixing the distal end of the operation tool inserted through the catheter body and the expansion / contraction member to the distal end of the expansion / contraction member, the compression tool in the axial direction is exerted on the expansion / contraction member by pulling the operation tool toward the proximal end side. On the other hand, a catheter having a therapeutic membrane attached to the expansion / contraction member is characterized.

  In the catheter of this aspect, by grasping the proximal end side portion of the operation tool protruding from the proximal end side opening of the lumen of the catheter body, the operation tool is pulled and retracted or pushed to advance. The expansion / contraction member attached to the distal end of the catheter body can be expanded or contracted in the radial direction. Therefore, for example, in a state where the expansion / contraction member is aligned with the damaged portion of the blood vessel, the expansion / contraction member is expanded and deformed by operating the operation tool and the therapeutic membrane is pressed against the inner wall surface of the damaged portion of the blood vessel. Can be used to stop bleeding.

  By adopting the expansion / contraction member composed of a plurality of wires, the blood flow in the blood vessel is allowed using the gap between the wires as a flow path even in a state of being expanded and deformed in the blood vessel. Therefore, unlike conventional hemostasis treatment using a balloon catheter, the blood flow is not blocked before and after the expanded and contracted expansion / contraction member while the blood vessel damage site is compressed and stopped with a therapeutic membrane, A stable blood flow can be secured.

  Further, after the compression hemostasis treatment, the expansion member is contracted and deformed to separate the therapeutic membrane from the damaged site of the blood vessel, and the therapeutic membrane can be extracted from the blood vessel together with the catheter body and the expansion / contraction member. Therefore, the therapeutic membrane is not placed in the blood vessel, and there is no problem caused by placing a foreign substance in the blood vessel as in the conventional hemostatic treatment using a stent graft.

  A second aspect of the present invention is the catheter according to the first aspect, wherein a slit extending in the length direction is provided in the therapeutic membrane.

  According to this aspect, when the expansion / contraction member is expanded and deformed, the deformation of the therapeutic membrane is easily permitted by the slit, so that the resistance exerted on the expansion / contraction member is also reduced and good operability is obtained.

  According to a third aspect of the present invention, in the catheter of the first or second aspect, the therapeutic membrane is attached to an intermediate portion in the axial direction excluding both end portions in the axial direction of the expansion / contraction member.

  According to this aspect, at both axial ends of the expansion / contraction member that is not covered with the therapeutic membrane, each passage on the inlet side and the outlet side in the direction of blood flow through the gap between the plurality of wires constituting the expansion / contraction member Is ensured, and the blood flow is allowed more smoothly with less resistance.

  According to a fourth aspect of the present invention, in the catheter according to any one of the first to third aspects, the therapeutic membrane is an elastic membrane that can be elastically deformed.

  According to this aspect, when the expansion / contraction member expands and contracts, the therapeutic membrane is elastically deformed so as to follow, so that the therapeutic membrane is pressed against the inner surface of the blood vessel wall and the blood vessel wall after hemostasis The separation from the inner surface can be more reliably performed.

  According to the catheter according to the present invention, the treatment membrane can be pressed against the damaged site of the blood vessel by pulling the operating tool to expand and deform the expanding / contracting member, whereby a hemostatic measure can be taken. It is also possible to sufficiently and stably secure the blood flow rate in the blood vessel by the expansion / contraction member configured as described above.

BRIEF DESCRIPTION OF THE DRAWINGS Front explanatory drawing of the notch which shows the catheter as the 1st Embodiment of this invention. Explanatory explanatory drawing of the II-II end surface of FIG. It is explanatory drawing of the use condition of the catheter shown by FIG. 1, Comprising: (a) shows the diameter reduction state of the expansion / contraction member, (b) shows the diameter expansion state of the expansion / contraction member. Front explanatory drawing corresponding to FIG. 1 which shows the catheter as another embodiment of this invention. Front explanatory drawing corresponding to FIG. 1 which shows the catheter as another embodiment of this invention.

  Hereinafter, in order to clarify the present invention more specifically, the configuration of the present invention will be described in detail with reference to the drawings.

  1 to 2 show a hemostasis catheter 10 as a first embodiment of the present invention. The hemostasis catheter 10 includes a catheter main body 12, an operation tube 14 formed of a hollow cylindrical body as an operation tool inserted into the catheter main body 12, and a cylindrical shape attached to the distal end of the catheter main body 12. The expansion / contraction member 16 and the hemostatic membrane 18 as a therapeutic membrane attached to the expansion / contraction member 16 in an extrapolated state are configured.

  More specifically, the catheter body 12 is composed of a tubular body having a lumen penetrating in the length direction, and has an outer diameter and a length that can be inserted into a blood vessel. The catheter body 12 has a suitable elasticity by adopting a conventionally known appropriate material so that it can be inserted up to a target treatment site in the blood vessel.

  On the other hand, the operation tube 14 has a length longer than the entire length of the catheter body 12 and an outer diameter smaller than the lumen of the catheter body 12. The operation tube 14 is inserted into the catheter main body 12, can be smoothly inserted and removed from the catheter main body 12, and can be elastically deformed following the catheter main body 12 while being inserted into the catheter main body 12. ing.

  Further, both ends of the operation tube 14 inserted into the lumen of the catheter main body 12 protrude from the distal end side opening and the proximal end side opening of the lumen of the catheter main body 12 by a predetermined length. ing. And the part which protruded from the distal end side opening part of the lumen | bore of the catheter main body 12 among the operation tubes 14 is made into the distal end side protrusion part 20, On the other hand, the part which protruded from the proximal end side opening part Is the proximal end side protrusion 22.

  Furthermore, the expansion / contraction member 16 has a mesh structure in which a plurality of flexible thin wire rods 24 are knitted together, and has a cylindrical shape as a whole. By adopting the mesh structure, the shape stability of the expansion / contraction member 16 during the diameter expansion deformation and the diameter reduction deformation is improved. As a result, as will be described later, the pressing force when the expansion / contraction member 16 is expanded and deformed to press the hemostatic film 18 against the inner surface of the blood vessel wall can be obtained more effectively. Note that the plurality of wires 24 are combined with a gap in a deformable state without being fixed to each other so that a sufficient gap can be obtained in the mesh (lattice) between the wires easily deformable. It is desirable that

  Furthermore, the wire 24 may be any flexible material that allows the expansion / contraction deformation of the expansion / contraction member 16, and may be a synthetic resin wire, for example. Wire material is adopted. A metal wire is easy to ensure characteristics such as strength, rigidity, and elasticity even with a small diameter, and is advantageous in securing the shape stability of the expansion / contraction member 16 and securing a gap between the wires. As the metal wire material, for example, stainless steel, tungsten, cobalt-chromium alloy, nickel-titanium alloy, etc., which are excellent in workability and have little influence on the human body are suitable.

  Moreover, it is preferable that the wire 24 has elasticity which restores to an initial shape. In particular, when the expansion / contraction member 16 has a substantially straight small-diameter cylindrical shape (reduced diameter state) as an initial shape and is deformed by being expanded by an external force or the like, the external force is released so that the elasticity of the wire 24 is increased. It is desirable that a restoring force to the shape is exerted. Such a restoring force is realized, for example, by using a superelastic metal such as a nickel-titanium alloy as each wire 24.

  As described above, the expansion / contraction member 16 composed of the plurality of wires 24 has the first fixing ring 26 attached to one end portion in the axial direction and the second fixing ring 28 attached to the other end portion in the axial direction. . Then, the first fixing ring 26 is fixed to the distal end of the catheter body 12, so that the expansion / contraction member 16 is attached so as to extend in the axial direction from the distal end of the catheter body 12. .

  Further, the expansion / contraction member 16 is inserted with the distal end side protruding portion 20 of the operation tube 14 protruding from the distal end of the catheter body 12, and the distal end of the distal end side protruding portion 20 is the second end. It is fixed to the fixing ring 28. Thus, by operating the proximal end side protruding portion 22 of the operation tube 14 to advance and hold the operation tube 14 to the back side (distal end side), the expansion / contraction member 16 is retained as shown in FIG. While the diameter-reduced state shown in (a) can be maintained, the expansion / contraction member 16 can be retained by retracting and holding the operation tube 14 toward the front side (proximal end side) as shown in FIG. It can be elastically deformed and maintained in the expanded diameter state shown in b).

  In addition, although the material of the 1st fixing ring 26 and the 2nd fixing ring 28 is not limited at all, For example, by forming using a radiopaque material, such as gold, platinum, a platinum-iridium alloy, It becomes possible to grasp the position in the blood vessel using radiation.

  On the other hand, the hemostatic membrane 18 attached to the expansion / contraction member 16 has a generally cylindrical shape corresponding to the outer peripheral surface shape of the expansion / contraction member 16 in a reduced diameter state as a whole. The axial length is shorter than the axial length of the expansion / contraction member 16 by a predetermined dimension. Further, the hemostatic membrane 18 is preferably made of a material having biocompatibility. Specifically, the hemostatic membrane 18 is made of an elastic material such as polyurethane, polyethylene, polyester, polypropylene, polyamide, polytetrafluoroethylene, polyvinylidene fluoride, or silicone rubber. It is formed of a thin film and can be elastically deformed.

  The cylindrical hemostasis film 18 is formed with one or a plurality of slits 30 (two equally on the circumference in this embodiment) at appropriate positions on the circumference. The slit 30 extends in the axial direction (the length direction of the hemostatic membrane 18) in the axial intermediate portion of the cylindrical hemostatic membrane 18. In particular, in the present embodiment, the slit 30 continuously extends in the axial direction with a length that is half or more of the entire length of the hemostatic membrane 18.

  The slit 30 only needs to easily allow the hemostatic membrane 18 to be deformed in the diameter increasing direction. For example, the slit 30 may be inclined with respect to the axial line of the hemostatic membrane 18 and extend in the axial direction. It is also possible to form a plurality of slits 30 on the circumference of the hemostatic film 18 with non-uniform intervals and non-uniform lengths. If the expansion / contraction deformation amount of the hemostatic film 18 is sufficiently secured by the elasticity of the hemostatic film 18 itself, it is not necessary to provide the slit 30.

  Such a cylindrical hemostatic membrane 18 is attached to the expansion / contraction member 16 by being extrapolated. Thereby, while the axial direction intermediate part of the expansion / contraction member 16 is covered with the hemostatic membrane 18, the axial both ends (the distal end side portion and the proximal end side portion of the expansion / contraction member 16) of the expansion / contraction member 16 The exposed state is not covered with the hemostatic film 18.

  Thereby, in the distal end side portion and the proximal end side portion that are not covered with the hemostatic film 18 of the expansion / contraction member 16, the outer region of the expansion / contraction member 16 through the mesh (lattice) in the wire member 24 having a mesh structure. Communication holes 32a and 32b are provided so that the inner region can communicate with each other.

  The cylindrical hemostasis film 18 is attached so as not to be detached from the expansion / contraction member 16 under the extrapolation state to the expansion / contraction member 16. Specifically, for example, the elasticity of the hemostasis film 18 is used so that the hemostasis film 18 is brought into close contact with the outer peripheral surface of the expansion / contraction member 16 to prevent the hemostasis film 18 from coming off in the axial direction, or the hemostasis film 18 is expanded. It is possible to prevent the hemostasis film 18 from being detached from the expansion / contraction member 16 by attaching to the wire 24 or the like. In addition, for example, the expansion / contraction member 16 is immersed in a melt that is a material of the hemostatic film 18, and the melt is attached, and then dried, so that it is stretched between the wires 24 constituting the expansion / contraction member 16. It is also possible to fix the hemostasis film 18 at the same time as molding so as to cover. The hemostasis film 18 formed in this way can be connected to the mesh between the wires 24 by, for example, excising both ends in the axial direction using a laser.

  If the hemostasis catheter 10 having the above-described structure is used, the damaged site of the blood vessel can be hemostatically, for example, by the following procedure.

  First, as shown in FIG. 3A, the hemostatic catheter 10 in which the expansion / contraction member 16 is in a reduced diameter state is inserted into the blood vessel 34 from an appropriate site. In that case, the expansion / contraction member 16 can be maintained in a reduced diameter state by holding the operation tube 14 so as not to move relative to the catheter body 12 in the backward direction.

  Then, the expansion / contraction member 16 is positioned inside the damaged portion 36 of the blood vessel 34. At this time, if necessary, the expansion / contraction member 16 is rotated around the central axis so that the slit 30 is removed from the damaged portion 36 so that the hemostatic film 18 faces the damaged portion 36 of the blood vessel 34. Align.

  Next, the proximal end side protrusion 22 of the operation tube 14 is pulled and retracted to move the operation tube 14 relative to the catheter body 12 in the proximal direction. As a result, as shown in FIG. 3B, the compression input in the axial direction acts on the expansion / contraction member 16, and the first fixing ring 26 and the second fixing ring 28 are displaced toward each other. Thus, each wire rod 24 constituting the expansion / contraction member 16 is curved and deformed so as to swell toward the outer periphery. In addition, the expansion deformation (expansion deformation) in the radial direction of the expansion / contraction member 16 becomes large at the axial central portion that is not constrained by the first and second fixing rings 26 and 28.

  Further, along with the expansion and contraction of the expansion / contraction member 16 in the radial direction, the hemostasis film 18 attached to the outer peripheral surface of the expansion / contraction member 16 is also pushed out radially and displaced. As a result, the hemostasis film 18 is pressed against the inner surface of the wall of the blood vessel 34, and the damaged part 36 of the blood vessel 34 is blocked with the hemostasis film 18. Therefore, by holding the operation tube 14 in the tension direction and holding the expansion / contraction member 16 in a diameter-expanded deformation state, the damaged portion 36 of the blood vessel 34 can be subjected to a compression hemostasis treatment with the hemostasis film 18.

  At this time, blood flowing in the blood vessel 34 flows into the expansion / contraction member 16 through one of the communication holes 32a, 32b of the wire 24 exposed on both axial sides of the expansion / contraction member 16, and is covered with the hemostatic film 18. The expansion / contraction member 16 flows and flows out of the expansion / contraction member 16 through the other of the communication holes 32a and 32b. In the present embodiment, blood may flow into or out of the expansion / contraction member 16 even through the slit 30 that has been greatly expanded in the expanded state of the hemostatic membrane 18.

  Therefore, even under a situation where the expanding / contracting member 16 is expanded and deformed and the damaged portion 36 of the blood vessel 34 is compressed and hemostatically treated with the hemostatic membrane 18, between the distal end side and the proximal end side of the expanding / contracting member 16. The blood flow in the blood vessel 34 is maintained.

  When the compression and hemostasis treatment of the damaged part 36 of the blood vessel 34 is completed, the operation tube 14 is advanced so as to be pushed into the catheter body 12, and the expansion / contraction member 16 is reduced in diameter as shown in FIG. . Along with this, the hemostatic membrane 18 attached to the expansion / contraction member 16 is also deformed in diameter, and the hemostatic membrane 18 is separated from the inner surface of the wall portion of the blood vessel 34. Thereafter, the hemostasis process can be completed by extracting the entire hemostasis catheter 10 from the blood vessel 34 while the expansion / contraction member 16 is restored and maintained in the reduced diameter state.

  As described above, when the hemostasis catheter 10 of the present embodiment is used, the catheter main body 12 is inserted into the blood vessel, and the proximal end side protruding portion 22 of the operation tube 14 is operated, whereby the damaged portion 36 of the blood vessel 34 is reached. Hemostasis treatment can be performed promptly. In addition, since the expansion / contraction member 16 has a substantially porous communication structure even in the state of expansion and deformation, the blood flow in the blood vessel can be sufficiently and stably secured even during such hemostasis treatment. This makes it possible to avoid risk due to blood flow inhibition.

  In particular, in this embodiment, since the expansion / contraction member 16 has a mesh structure formed by braiding the metal wire 24, the wire 24 can be made sufficiently small in diameter to further reduce blood flow resistance. In addition, the strength and pressure resistance during expansion deformation of the expansion / contraction member 16 can be ensured, and the hemostatic membrane 18 can be strongly pressed against the damaged portion 36 of the blood vessel 34 to stop hemostasis.

  Furthermore, in this embodiment, since the operation tube 14 is employed as the operation tool, the expansion / contraction member 16 can be guided to the target site along the guide wire previously inserted into the blood vessel, and the operation is easy. It becomes.

  As mentioned above, although embodiment of this invention has been explained in full detail, this invention is not limited by the specific description of this embodiment. For example, the size and shape of the hemostatic film 18 attached to the expansion / contraction member 16 and the position on the expansion / contraction member 16 are not particularly limited, and one axial direction of the expansion / contraction member 16 is shown in FIG. The hemostatic membrane 18 may be attached to the side. Although not shown, it is also possible to attach a plurality of independent hemostatic membranes at a predetermined distance in the circumferential direction or the axial direction of the expansion / contraction member 16. Further, a communicating hole is formed at a position that avoids the damaged portion 36 of the blood vessel 34, such as both axial end portions of the hemostatic membrane, so that the expanding and contracting member 16 can be passed through the communicating hole under the expanded diameter deformation state. Blood flow may be allowed.

  Further, the wire 24 constituting the expansion / contraction member 16 does not need to have a mesh structure as in the above-described embodiment. For example, as shown in FIG. 5, a plurality of wires 24 extending in the axial direction are circumferentially arranged. It is also possible to configure the expansion / contraction member 16 by arranging them at appropriate intervals. The plurality of wires 24 may be slightly inclined in the circumferential direction with respect to the axial line. Incidentally, in FIGS. 4 and 5, in order to facilitate the understanding, the same reference numerals as those in the above embodiment are given to members and parts having the same structure as in the above embodiment.

  Further, the first fixing ring 26 and the second fixing ring 28 are omitted, and the proximal end of the expansion / contraction member 16 is directly fixed to the distal end of the catheter body 12, or the distal end of the operation tube 14 is fixed to the expansion / contraction member. It can also be fixed directly to the 16 distal ends.

  In addition, as an operation tool, an operation wire may be employed instead of the operation tube 14 in the embodiment.

  Furthermore, instead of the hemostatic film 18 in the above-described embodiment, a drug supply film for supplying and applying a drug or the like to the target site of the blood vessel can be employed. For example, it can be used to apply a drug for preventing restenosis (paclitaxel, rapamycin, β-lapachone, etc.) to the treatment site of a vascular stenosis for the purpose of expanding the stenosis of the coronary artery. Such a drug is coated or impregnated on the drug supply film and held on the expansion / contraction member, and the expansion / contraction member is guided to the treatment site in the blood vessel by the same operation as in the above-described embodiment, so that the diameter is expanded. Thus, the drug supply membrane can be pressed against the target site in the blood vessel, and the drug can be eluted and supplied directly. In this way, by applying the present invention and supplying a drug into a blood vessel, unlike the conventional technique using a balloon as described in, for example, Japanese Translation of PCT International Publication No. 2010-509991, the drug can be applied without stopping the blood flow. It becomes possible to do.

10: hemostasis catheter, 12: catheter body, 14: operation tube, 16: expansion / contraction member, 18: hemostasis membrane, 24: wire rod, 30: slit

Claims (4)

Using an expansion / contraction member that is composed of a plurality of wires and expands and deforms in the radial direction by compression input in the axial direction,
The expansion / contraction member is attached to the distal end of the catheter body, and the distal end of the operation tool inserted through the expansion / contraction member is fixed to the distal end of the expansion / contraction member, thereby pulling the operation tool toward the proximal end side. While allowing the expansion / contraction member to be subjected to axial compression input,
A catheter comprising a therapeutic membrane attached to the expansion / contraction member.   The catheter according to claim 1, wherein a slit extending in a length direction is provided in the therapeutic membrane.   The catheter according to claim 1 or 2, wherein the therapeutic membrane is attached to an intermediate portion in the axial direction excluding both end portions in the axial direction of the expansion / contraction member.   The catheter according to any one of claims 1 to 3, wherein the therapeutic membrane is an elastic membrane that can be elastically deformed.

Images