JP2005537073A - Blood control device - Google Patents

Abstract

The present invention is a cardiovascular stent comprising a generally tubular body and a prosthetic valve (22) capable of moving from a first open state to a second closed state, wherein in use, the stent is Installed between one section and a second section, movement of blood in a first direction causes the valve to move to an open state, movement of blood in a second opposite direction causes the valve to move The present invention relates to a cardiovascular stent (18) characterized by being moved to a closed state. In particular, a stent is provided to connect the left ventricle of the heart to the coronary artery and allows blood to flow through the stent from the left ventricle of the heart to the coronary artery, but does not allow blood to flow from the coronary artery to the left ventricle of the heart. Minimize backflow.

Description

  The present invention relates to a stent for connecting a first section to a second section. In particular, the invention relates to a cardiovascular stent, such as for connecting the left ventricle of the heart to a coronary artery.

  Coronary artery disease is a major problem around the world, especially in western societies. Coronary arteries, like other blood vessels, can become clogged with plaque and impair the efficiency of the heart's pumping action. This can lead to heart failure, angina, and death.

  A number of methods, such as bypass surgery and balloon angioplasty, are used to treat clogged coronary arteries.

  In bypass surgery, one or more venous segments are inserted between the aorta and the coronary arteries to block the coronary arteries so that unobstructed blood flow and thereby blood supply to the heart is achieved. Form a bypass in the part. More than 500,000 bypass procedures are performed annually in the United States.

  However, bypass surgery is a very annoying means requiring expensive and time consuming surgery. During the bypass surgery, an incision is made through the patient's skin and the patient is attached to the bypass pump while the heart stops beating so that the heart can operate. A saphenous vein graft is taken from the patient's leg and the vein is implanted at a location between the aorta and the coronary artery to allow unobstructed blood flow. This surgical procedure is traumatic to the patient and requires a sufficient length of hospitalization and a long recovery period.

  In some situations, balloon angioplasty means may be used instead of the method described above to treat coronary plaque occlusion. In this case, a deflated balloon catheter is placed in a constricted portion of the coronary artery. The balloon is then inflated to a high pressure to transmit the surrounding pressure to the plaque that occludes the artery, compressing the plaque and thereby increasing the diameter through which blood flows.

  Balloon angioplasty is minimally invasive, but this measure is only used under limited circumstances.

  In addition to the above two techniques traditionally used to treat coronary occlusions, more recent measures have bypassed the occluded portion of the coronary arteries to allow blood to flow to the left ventricle of the heart. Allows a stent to be placed between the coronary artery and the left ventricle of the heart so that it can flow safely from the coronary artery to the coronary artery. The stent can be placed between the left ventricle of the heart and the coronary arteries using less invasive means than is required for coronary artery bypass surgery.

  Typically, a stent is a conduit having a passage extending longitudinally therethrough. Generally, a stent is cylindrical in cross section and is generally an elongated tube.

  A disadvantage of providing a stent that extends from the left ventricle of the heart to the coronary artery is that blood can flow back from the coronary artery to the left ventricle of the heart during the relaxation phase. Such a back flow of blood is not preferable.

  Some reports indicate that if oxygen-rich blood flows back into the left ventricle of the heart during the relaxation phase, the myocardium may not be adequately supplied with blood. This can lead to myocardial ischemia. In fact, some studies have shown that the measurement of blood flow during systole and regurgitation during relaxation is only 30% of the net flow rate of blood from the left ventricle to the artery after introduction of the stent between its two segments. Suggests that only% is achieved.

  There remains a need for improved (more efficiently) stents.

  The inventor has overcome many of the problems of prior art stents.

  According to a first aspect of the present invention, a cardiovascular stent comprising a generally tubular body and an artificial check valve capable of moving from a first open state to a second closed state, in use The valve takes the open state by movement of fluid in a first direction through the stent, for example blood, and the valve takes the closed state by movement of fluid in the second opposite direction. A cardiovascular stent is provided.

  The valve is determined to be closed when restricting the passage of fluid, for example, in a second direction from the second section to the first section. A stent as described by the present invention is used to allow fluid movement from a close location in a first cardiovascular segment to a distant location in the same or different cardiovascular segment. Can be done.

  Preferably, in the closed state, the valve moves the fluid in the second direction to less than 40% of that in the open state.

  More preferably, the valve, when closed, provides fluid movement in the second direction less than 30%, preferably less than 20%, even more preferably less than 10%, when the valve is open. More preferably less than 5%, even more preferably less than 2%, and most preferably less than 1%.

  A stent with a prosthetic valve is advantageous because it can restrict the passage of fluid in a second direction, eg, from the second segment to the first segment, eg, from the coronary artery to the left ventricle of the heart. This provides an increase in the net flow rate of blood from the first segment to the second segment, e.g. the possibility that the myocardium where the coronary artery provides the supply of blood cannot fully receive the supply of blood. Minimize.

  In such an embodiment, the movement of fluid, for example in a first direction from the first section to the second section, causes a pressure differential across the valve sufficient for the valve to assume an open state. For example, the valve is closed due to fluid flow in a second opposite direction from the second section across the valve to the first section.

  In addition, the use of a prosthetic valve has the additional advantage that veins need not be taken from the patient.

  Preferably, the valve is closed when there is no fluid movement in either the first or second direction. Thus, preferably, the valve is elastically moved to a closed configuration.

  Preferably, the stent is used to connect cardiovascular sections together.

  Preferably, the first segment is a first cardiovascular segment and the second segment is a second cardiovascular segment.

  A cardiovascular stent is a stent that is suitable for use in connecting a portion of a cardiovascular segment to another portion of the same cardiovascular segment or to another cardiovascular segment.

  A cardiovascular segment is defined as any tissue or structure of the circulatory system that includes arteries, veins, or cardiac compartments.

  In a preferred embodiment, the stent is for use as a stent between the left ventricle of the heart and the coronary artery.

  Preferably, the valve is made of an elastic material.

  A valve formed of an elastic material requires very few mechanical elements that allow the valve to move between the open and closed states, thereby potentially damaging red blood cells that have moved through the stent. This is advantageous because there is almost no.

  Preferably, the flexible elastic material is a suitable biologically stable biocompatible polymer.

  Preferably, the flexible elastic material comprises Elast-Eon (R), Biomer or Biospan.

  Details of the polymer, Elast-Eon (R), can be found in WO98 / 13405, WO92 / 00338, WO92 / 09467, WO99 / 01496.

  In an embodiment in which the valve is formed of an elastic material, in the closed state, preferably at least the opening formed of the elastic material of the valve is elliptical in cross section. This oval restricts blood flow from the second cardiovascular segment to the first cardiovascular segment.

  Preferably, movement of fluid, such as blood, through the stent in a first direction encourages the valve elastic material to take a form in which the opening defined by the material is substantially circular in cross section; This configures the valve so that increased liquid can flow through the valve and thus through the stent. Thus, the circular opening provides increased flow from the first cardiovascular segment to the second cardiovascular segment.

  In other embodiments, the valve includes at least two leaflets formed of an elastic material and fluid is flowing through the stent in a second direction or when fluid is not flowing through the stent. The leaflets may be opposed to each other so that the passage of fluids such as blood is minimized. In this embodiment, movement of fluid in a first direction, eg, from the first section to the second section, moves the leaflets of the valve away from each other, allowing fluid to pass through the stent.

  The valve may be placed in any position on the stent.

  Preferably, the valve is located at either end of the stent.

  Such an embodiment is advantageous because the valve portion of the stent can extend into the cardiovascular segment. This is because, for example, if a stent is used between the left ventricle of the heart and the coronary artery, placing the valve in the myocardium will limit the movement of the valve when the muscle contracts and relaxes It can be important because there is a possibility.

  Preferably, the valve is integral with the stent.

  A stent may be placed and valve means may be provided to the stent, but the stent and valve may be provided in a single unit so that they can be placed between cardiovascular sections in a single procedure. preferable.

  The stent may be composed of any suitable material.

  The stent may include a suitable hard biocompatible metal and may include, but is not limited to, one or more of stainless steel, spring steel, nitinol, and / or a flexible elastic material.

  Preferably, the stent may be composed of a reticulated skeleton.

  Preferably, the stent includes a flange portion disposed toward or at one end of the stent.

  This is advantageous because when the stent is pushed into the tissue to provide a passage between the two sections, the depth of the stent in the tissue can be controlled by the flange. For example, if the flange is on the back or back of the stent, the front will be the part that is first inserted into the tissue, and the back of the stent as it is pushed into the tissue from one section to the other. The provided flange prevents the stent from being pushed too far into the tissue and ensures that the lumen of the stent extends from the first section to the second section. Furthermore, the flange portion can also be used to secure the stent in place by preventing tissue around the flange from moving the stent from the first section to the second section.

  In a preferred embodiment, the valve includes at least one cantilevered member having a first end and a second end, the cantilevered member being hinged to the stent at the first end; The cantilever member can elastically rotate from a first extended state in which the valve is closed to a second state in which the valve is open. In a preferred example of such an embodiment, the material forming the valve and defining the opening of the valve in the open state is the material when the second end of the cantilevered member is extended. It is drawn so that the area of the formed opening is reduced.

  In such a preferred example of this embodiment, fluid movement in the first direction through the stent causes the second end of the cantilevered member to move radially toward the longitudinal axis of the center of the stent. Move elastically inward. This movement of the second end of the cantilevered member causes the material forming the valve and defining the valve opening to have a wide opening (preferably substantially) through which increased fluid can flow through the valve. A circular shape). When the fluid flow in the first direction is reduced or when there is no fluid flow in the first direction, the cantilevered member moves elastically to the extended state. The second end movement of the cantilevered member to the extended state pulls the material forming the valve and defining the valve opening to form an opening of reduced area in cross-section. The opening has a smaller area in cross section than the substantially circular opening, thereby restricting the flow of fluid in both the first and second directions.

  More preferably, the valve includes two cantilevered members. In this embodiment, the two cantilevered members are elastically hinged to the stent at the first end of the members. In the absence of fluid flowing through the stent, the second end of the cantilevered member moves radially outward to an extended state. Preferably, it is larger in the radial direction than the circumference of the stent. The material forming the valve and defining the valve opening when in the open state is formed by the material when the second end of the cantilevered member is in the extended state. The area of the opening is kept to be reduced and forms an ellipse in cross section.

  Such an embodiment can function as follows. Movement of the fluid through the stent in the first direction elastically moves the second end of the cantilevered member radially inward toward the longitudinal axis of the center of the stent. The movement of the second end of the cantilevered member forms a substantially circular opening through which the material forming the valve and defining the valve opening can flow blood in cross section through the valve. Let me do that.

  When the fluid flow in the first direction is reduced, or when there is no fluid flow in the first direction, the second end of the cantilevered member moves elastically again to the extended state. The movement of the second end of the cantilevered member to their extended state again causes the material forming the valve and defining the opening of the valve to have an oval opening of reduced area in cross section. Pull to form. Since the opening has a smaller area in cross section than the substantially circular opening, fluid flow is limited in both the first and second directions.

  The circular cross section allows for increased flow through the stent and the oval cross section minimizes flow in the second direction.

  In such an embodiment, the opening formed by the elastic material is preferably drawn from a substantially circular cross-section to a substantially oval cross-section, and in use, from the second section to the first Restrict the flow of liquid to the compartment.

  Preferably, the stent is configured to expand in diameter from a “collapsed” configuration to an “expanded” configuration, wherein the stent has a smaller diameter than in the expanded configuration.

  Such a structure allows the stent to be properly attached to a living body in a narrowed collapsed form and then expanded from the collapsed form to a fully expanded form.

  The diameter of the stent can be increased from a collapsed state to an expanded state using any suitable procedure, for example, using a balloon angioplasty procedure.

  To place such a stent, the stent may be delivered in a collapsed state with a catheter in vivo, for example, to the desired location of the myocardium between the left ventricle and the coronary artery. A properly placed stent may then be placed by expanding the balloon attached to the stent so that the diameter of the stent increases from the collapsed stent state to the increased diameter of the expanded stent. .

  In addition to expanding the diameter of the stent by means of a balloon, the stent is fixed in an expanded state to hold the stent in the myocardium and maintain the stent in an expanded state with an increased diameter.

  A collapsed stent can be deployed by any suitable technique with minimal invasiveness, such as percutaneous delivery.

  In other embodiments, the stent may be constructed of a memorizing material so that once properly placed in the body, the diameter of the stent expands from a collapsed state to a fully expanded state.

  For example, in such an embodiment, the stent assumes a collapsed state at a low temperature, eg, a temperature lower than body temperature, but takes an expanded state at body temperature.

  In one preferred embodiment, the valve of the stent moves to a closed state as the stent diameter increases from a collapsed state to an expanded state when the stent is properly placed in the body.

  In a particularly preferred embodiment, the valve comprises at least one cantilevered member as described above. Increasing the diameter of the stent, for example during stent deployment, causes the valve to take a closed configuration.

  In this embodiment, the cantilevered member may be elastically hinged to the stent at the first end, with the second end of the cantilevered member extended upon expansion of the stent diameter. Is pulled, the material forming the valve and defining the opening of the valve in the open state is reduced, thereby reducing the area of the opening formed by the material.

  More preferably, the valve comprises two cantilevered members, the stent diameter being reduced during stent deployment from the collapsed configuration in which the valve portion of the stent is open, and the valve is closed. Try to expand to an expanded form. A circular cross section allows increased flow through the stent, and an elliptical cross section minimizes flow in the second direction.

  In such an embodiment, the opening formed by the elastic material is preferably drawn from a substantially circular cross-section to a substantially elliptical cross-section, and in use, from the second section to the first Restrict fluid flow to the compartment.

  The diameter and length of the stent depends on its application. For example, the stent may be of a length that is adapted to extend between the left ventricle of the heart and the coronary artery.

  Preferably, the stent is 2-15 millimeters in diameter.

  The stent may be constructed such that multiple stents are placed “end to end” and the effective length of the stent array is increased.

  Thus, in certain preferred embodiments, the stent is elastically deformable at least at one end so as to receive and couple a second stent.

  In other embodiments, the stent may be shaped so that it can be coupled to the second stent at one or both ends.

  The stent may include a chemical coating and / or a chemical and / or mechanical coating, such as a TEFLON® membrane, to minimize stenosis.

  As mentioned above, the stent of the present invention can be used to connect or repair two cardiovascular segments.

  For example, the stent of the present invention can be used to connect a coronary artery to the left ventricle of the heart.

  The stent of the present invention may also be used for non-coronary structures such as non-coronary veins and / or arteries.

  For example, a stent may be used to connect a first portion of the ascending venous structure, such as the saphenous vein, and a second portion of the same ascending venous structure. If the region between the first and second portions of the femoral artery is damaged or occluded, the stent of the present invention allows blood movement from the first portion to the second portion. Therefore, it may be disposed between the first and second portions.

  Thus, in use, the stent of the present invention is provided between first and second portions of a vein, such as the saphenous vein, to flow blood from the first portion to the second portion. In doing so, it restricts the flow of blood from the second part to the first part. Such an arrangement can be used to treat varicose veins.

In a second aspect of the invention, a method for treating complete or partial blood occlusion, comprising:
The stent means comprises at least one stent of the first aspect of the invention;
A first end of the lumen of the stent means communicates with a cardiovascular segment on a first side of the occlusion;
The second end of the lumen of the stent means communicates with the cardiovascular segment on the other side of the occlusion, and blood flows from the first side of the cardiovascular segment to the other side through the lumen of the stent means. There is provided a method of treating a complete or partial occlusion of a blood vessel, including the step of providing a stent means that allows for this.

  The cardiovascular segment on each side of the occlusion may be the same blood vessel in which the occlusion is present.

  In other embodiments, the cardiovascular segment may be a different segment, eg, the left ventricle of the heart and the coronary artery.

  The stent means may comprise a single stent. Alternatively, the stent means may include a plurality of stents arranged so as to be connected in the longitudinal direction, and blood may flow from the stent at the first end of the stent means to the stent at the second end of the stent means. .

  Preferably, the stent means comprises one stent of the first aspect of the present invention.

  Further, in a preferred embodiment, the method places a stent means between sections to reduce the diameter of the stent means from a reduced diameter in the collapsed state to an increased diameter in the expanded state. Including a step of enlarging.

In a particularly preferred embodiment, the method comprises
Inserting a stent at a location between the first cardiovascular segment and the second cardiovascular segment;
The valve moves in a closed state, but when the fluid flows in a first direction from the first cardiovascular segment to the second cardiovascular segment, the diameter of the stent is increased so that it can move in the open state. Process.

  According to a further aspect of the present invention, there is provided a method for treating varicose veins wherein a stent means comprising at least one stent of the first aspect of the present invention is disposed in a vein, or all or a portion of a vein is present in the present invention. There is provided a method of treating varicose veins comprising replacing a stent means comprising at least one stent on the first side of

  As described above, the stent means includes a plurality of stents arranged so as to be connected in the longitudinal direction, and blood flows from the stent at the first end of the stent means to the stent at the second end of the stent means. You may be able to do that.

  As described above, a preferred embodiment of the first aspect of the present invention provides a stent including a valve with at least one cantilevered member. Use of such a valve is not limited to in vivo use. Thus, in a further independent aspect, tube means is provided, the tube means comprising a valve comprising at least one cantilevered member having a first end and a second end, the cantilevered member comprising: The cantilevered member is hinged to the tube at the first end and is elastically moved from a first extended state in which the valve is closed to a second state in which the valve is open. It is possible to rotate.

  A tube with such a valve may be used to couple the first cardiovascular section with the section of the cardiovascular device or vice versa.

  In a further embodiment, a tube with such a valve may be used to connect the first and second sections of the device to transport a fluid, such as blood.

  For example, such a tube with at least one cantilevered member can be used in a machine or device such as a dialysis machine that is used to move fluid, eg, blood.

  A further independent aspect of the invention is an apparatus for fluid movement.

  Preferably the fluid is blood.

  The invention will now be described, by way of example only, with reference to the accompanying drawings.

  As shown in FIG. 1, the coronary artery 10 is known to be branched from the aorta 12 and positioned along the outer surface of the heart wall 14.

  After oxygenation of the blood, the oxygenated blood flows from the heart 16 to the aorta 12 and the rest of the body. Some of the oxygenated blood is circulated along the coronary artery 10 to add oxygen to the myocardium. In some individuals, an occlusion is formed in the coronary artery due to the formed plaque. These obstructions can cause a variety of symptoms and diseases ranging from mild angina to heart attacks.

  To allow blood to flow around the occlusion in the coronary artery and at least partially restore the oxygenated blood flow through the coronary artery, as shown in FIG. 2, from the left ventricle 20 of the heart to the coronary artery By providing a stent 18 extending to 10, a bypass can be created in the occluded portion of the coronary artery. As shown in FIG. 2, the placement of the stent 18 allows blood to flow from the left ventricle 20 of the heart into the coronary artery 10 without difficulty.

  Using the stent 18 to allow blood to flow through or around the occlusion of the coronary artery 10 is deployed and attached using a technique that is minimally invasive. This is preferred over traditional bypass surgery. In general, stents previously used to connect the left ventricle 20 of the heart to the coronary artery 10 are hollow, made of a biocompatible material, such as a titanium alloy, a nickel alloy or a biocompatible polymer. It is a stent formed by the tube. These tubes may be provided and placed between the left ventricle 20 of the heart and the coronary artery 10 in a collapsed state, and a balloon catheter that can be inflated when properly placed. Or other methods may be used to expand from a collapsed state to a fully expanded state.

  While such stents allow blood flow from the left ventricle 20 of the heart to the coronary arteries, conventional stents do not have artificial or mechanical means to limit blood regurgitation.

  As shown in FIG. 3, the stent of the present invention includes a prosthetic valve 22, an example of which is a portion of a flexible elastic material disposed at the second end 24 of the stent. This flexible elastic material is desirably integral with the rest of the stent.

  The valve may be formed during the manufacture of the stent prior to insertion of the stent into the living body.

  Alternatively, as shown in the stent embodiment of FIG. 4, when the stent is placed in vivo, the valve is a cantilevered member while the stent moves from a collapsed state to an expanded state. It can be created by rotation.

  In this embodiment, as shown in FIG. 4 a, the elastic material held by the two cantilevered members 21 forms a substantially cylindrical opening 28 in the collapsed state.

  The cantilevered member is bonded to the stent only at the first end and with the rigid biocompatible metal portion 23 of the stent. During stent deployment (diameter increase), the second ends of the cantilevered members move away from each other. This movement pulls the elastic material so that the cross-sectional shape changes from a substantially circular shape to a substantially elliptical shape. This change in cross-sectional shape restricts blood flow in the second direction from the second section through the stent to the first section. The flow of blood through the stent from the first section to the second section causes the leaflet material to elastically move the cantilevered members toward each other and the valve opening is substantially circular in cross section. Press to become. The area of the circular cross section is larger than the elliptical cross section, so that blood can easily flow from the first section to the second section. In the relaxation phase, when blood is not pushed from the first section to the second section, the pressure of blood on the valve material decreases. The second ends of the elastic cantilever members again move away from each other and cause the valve member to form an elliptical cross section.

  If more than one cantilevered member is used, for example, three, four, or five cantilevered members, the cross-sectional shape is not elliptical when deployed, but substantially It turns out that it becomes a triangle, a rectangle, or a pentagon. Different shaped openings may be used as appropriate to restrict blood flow from the second section to the first section. In addition, differently shaped openings can be selected to minimize compression on the arterial wall caused by the cantilevered member.

  In some embodiments, a valve formed of an elastic material does not require an increase in the diameter of the stent in order for the elastic material to assume a closed state. In this embodiment, the cantilevered member need not pull the valve material to the closed state and the valve is manufactured in the closed state. The flow of blood in the first direction from the first section to the second section causes the elastic material to be open.

  In addition to the cantilevered members disclosed herein, various methods are possible for causing the elastic material to close after expansion from the collapsed state of the stent structure.

  During systole (heart contraction), blood is pumped by the heart through the stent 18 from the first end 26 located in the left ventricle 20 of the heart to the second end 24 of the stent located in the coronary artery. During heart contraction, the left ventricular blood of the heart is moved in a first direction through the stent, moving the valve from an elliptical (closed state) to an open (circular cross-sectional shape) state.

  In the closed state, the elliptical shape reduces the area through which blood can flow from the second section to the first section to 10% of the area of the valve open state. In this way, blood backflow is reduced when blood is not pumped through the stent from the first section to the second section.

  Typically, the backflow of blood through the valve from the second segment to the first segment should be 25% of what would be expected when the valve was open.

  The movement of the elastic material in this way from an ellipsoid (closed state) to a circular (open state) causes the blood to flow from the first section (in this case the left ventricle of the heart) to the second section (in this case coronary). The area of the opening 28 that can flow into the artery (artery) is increased to allow unhindered flow of blood through the valve.

  When the pressure of the blood flow in the first direction through the valve is reduced, the elastic material causes the material (and, in certain embodiments, the cantilevered member of the hard portion of the stent) to The valve causes a resting state in which the opening to the coronary artery forms an ellipse. This change in the shape of the opening reduces the area of the opening located in the second section, minimizing blood flow from the coronary artery to the left ventricle of the heart.

  The movement of the stent from the collapsed state to the expanded state causes the stent to be more firmly fixed by the myocardium. A flange or other protrusion may also be provided on the stent to assist in stent placement.

  As shown in FIGS. 6 and 7, at least two stents are aligned along the longitudinal axis so that blood passes from the lumen of the first stent to the lumen of the second adjacent stent. be able to. By aligning several stents together, either between two different cardiovascular segments such as the left ventricle of the heart and a coronary artery, or within the same cardiovascular segment such as a blood vessel, Blood may move from the first near position to the second far position.

  By aligning multiple stents along the longitudinal axis, it is possible to provide blood flow over a relatively long distance. In addition, since each of the stents is equipped with a valve, the stent more closely resembles a situation that prevents backflow of blood in a real vein and allows blood to move upward. An example of where it is required to move blood up is the patient's foot when the patient is standing.

  The valve on each of the stents allows blood to be pushed through the valve during heart contraction, but minimizes reverse movement of blood during the relaxation phase. This allows blood to move up the foot and through the body.

  To allow the stents to be tied together, the first end of the stent can be deformed (as shown in FIG. 7 (30)) and the second stent can be partially inserted therein. Alternatively or additionally, the stent may be expanded (FIG. 7 (32)) to allow entry of a second stent as shown in FIG.

  It will be appreciated that various modifications and changes can be made without departing from the scope of the invention. In particular, it will be appreciated that the valve may be formed of at least two leaflets and in opposition may be opposed to each other to minimize blood flow from the second cardiovascular segment to the first cardiovascular segment. . Upon movement of blood in the first direction from the first section to the second section through the stent, these leaflets are pushed away from each other and blood from the first section to the second section. May be able to flow. In the relaxation phase, the two leaflets of the valve are opposed to each other by the elasticity of the material. Alternatively, various methods may be used to align the stents along their length, for example providing a coupling means.

FIG. 2 is an illustration of an embodiment of the stent of the present invention extending from the left ventricle of the heart to the coronary artery. FIG. 3 is an enlarged view of an embodiment of the stent of the present invention connecting the left ventricle of the heart to the coronary artery. It is explanatory drawing of the embodiment of the stent of this invention which the 2nd terminal of a stent is a closed state. (A) is explanatory drawing of the embodiment of the stent of a collapsed shape, (B) is explanatory drawing of the embodiment of the stent of this invention which is an expanded shape. It is explanatory drawing of the embodiment of the stent of this invention when the 2nd terminal of a stent is an open state. At least two of the stents of the present invention aligned to connect along their longitudinal axis so that blood can flow from the lumen of the first stent to the lumen of the second adjacent stent. It is explanatory drawing of an embodiment. A stent according to an embodiment of the present invention aligned along its length, wherein the first stent has a distal end shaped to receive the second stent and the other stent is one FIG. 10 is an illustration of what can be deformed to receive a stent inside the distal end.

Claims (20)

  A cardiovascular stent comprising a generally tubular body and an artificial check valve capable of moving from a first open state to a second closed state in a first direction through the stent in use. The cardiovascular stent is characterized in that the valve is in the open state by movement of fluid and the valve is in the closed state by movement of fluid in the second opposite direction.   The cardiovascular stent according to claim 1, wherein the valve is formed of an elastic material.   In use, the movement of fluid in the first direction through the stent encourages the resilient material of the valve to take a form in which the opening defined by the material is substantially circular in cross-section. The cardiovascular stent of claim 2, wherein the valve is configured such that increased fluid can flow through the valve and thus through the stent.   When the valve includes two leaflets formed of an elastic material and when fluid flows in the second direction through the stent in use, or when no fluid flows through the stent, the leaflet is fluid The cardiovascular stent according to claim 2 or 3, wherein the cardiovascular stents are opposed to each other so as to minimize the passage of each other.   The valve includes at least one cantilevered member having a first end and a second end, the cantilevered member being hinged to the stent at the first end, the cantilevered The member according to claim 1, wherein the member is capable of elastically rotating from a first extended state in which the valve is in a closed state to a second state in which the valve is in an open state. The cardiovascular stent of any one of Claims.   6. The cardiovascular stent of claim 5, wherein the valve includes two cantilevered members.   The stent can be configured such that the diameter of the stent can be increased from a “collapsed” configuration to an “expanded” configuration, wherein the stent has a smaller diameter than the expanded configuration. A cardiovascular stent according to any one of the preceding claims.   As the diameter of the stent expands, the second end of the cantilevered member pivots to an extended state, pulling the material that forms the valve and defines the valve opening in the open state. 8. A cardiovascular stent according to claim 7 when dependent on claim 5 or claim 6, wherein the area of the opening formed by the material is reduced.   A cardiovascular stent according to any one of the preceding claims, characterized in that the stent is elastically deformable at one or both ends so as to receive and couple a second stent.   The cardiovascular stent according to any one of the preceding claims, characterized in that the stent is shaped so that it can be coupled to a second stent at one or both ends.   A cardiovascular stent according to any one of the preceding claims for connecting a coronary artery to the left ventricle of the heart.   The cardiovascular stent according to any one of claims 1 to 10, for connecting a first part of the ascending venous structure and a second part of the same ascending venous structure. A method of treating a complete or partial occlusion of a blood vessel, comprising:
A stent means comprising at least one stent according to claims 1-12, wherein a first end of the lumen of the stent means communicates with a cardiovascular segment on a first side of the occlusion;
The second end of the lumen of the stent means communicates with the cardiovascular segment on the other side of the occlusion, and the other end of the cardiovascular segment from the first side of the occlusion through the lumen of the stent means. A method of treating complete or partial occlusion of a blood vessel comprising the step of providing a stent means characterized by allowing blood to flow to the sides of the blood vessel.   The stent means includes a plurality of stents arranged so as to be connected in the longitudinal direction, and allows blood to flow from the stent at the first end of the stent means to the stent at the second end of the stent means. 14. A method according to claim 13 characterized in that   15. The method of claim 13 or claim 14, further comprising increasing the diameter of the stent from a reduced diameter in the collapsed state to an increased diameter in the expanded state. A method for treating varicose veins, comprising:
13. A method of treating varicose veins comprising the step of placing a stent means comprising at least one stent according to claim 1 in a vein. A method for treating varicose veins, comprising:
A method for treating varicose veins comprising the step of replacing a stent means comprising at least one stent of the first aspect of the present invention with at least a portion of a vein.   Tube means including a tubular portion and a valve, wherein the valve includes at least one cantilevered member having a first end and a second end, the cantilevered member at the first end of the tubular portion. The cantilevered member can be elastically rotated from the first extended state in which the valve is closed to the second state in which the valve is in the open state. Tube means characterized in that there is.   19. Tube means according to claim 18, characterized in that when moving from the closed state to the open state, the opening of the valve is moved from an elliptical shape to a substantially circular shape.   20. An apparatus for moving a fluid comprising the tube of claim 18 or 19.

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