US20060241745A1 - Blood flow controlling apparatus - Google Patents

Abstract

A blood flow controlling apparatus, which is configured to be implanted into a blood circulatory system of a patient, comprises an anchoring means, which is arranged to fix the position of the apparatus in the blood circulatory system, and a valve means being connected to the anchoring means. The valve means is configured to be arranged within the blood circulatory system and is configured to be extendable in a direction transverse to blood flow in order to make contact with native tissue when inserted in the blood circulatory system. The valve means is further configured to release said contact as a result of being exposed to blood flow in a permitted direction.

Description

CROSS REFERENCE TO A RELATED PATENT APPLICATION
• The present application claims priority to Swedish Patent Application Serial No. 0500891-7, filed on Apr. 21, 2005, the disclosure of which is incorporated by reference herein in its entirety.
TECHNICAL FIELD
• The present invention relates to a blood flow controlling apparatus, which is configured to be implanted into a blood circulatory system of a patient, and to a method for treatment of leaking heart valves.
BACKGROUND OF THE INVENTION
• Heart valve disease is a very common problem. Each year, half a million people in the world develop heart valve disease. 200,000 are too sick to be treated, but the rest are treated. At present, the treatment of heart valve disease consists of either heart valve repair or valve replacements. Both methods require open-heart surgery, by the use of total cardiopulmonary by-pass, aortic cross-clamping and arrest of the heart. To certain groups of patients, open-heart surgery is particularly hazardous. However, a less invasive method for repair of heart valves is considered generally advantageous.
• Heart valve insufficiency may arise from a dilation of the valve annulus, whereby the leaflets of the heart valve are moved away from each other such that the area of coaptation is minimized or vanished. The area of coaptation is the area where the leaflets of heart valves lean against each other, thereby closing the valve opening sufficiently. Thus, an existing gap or incomplete area of coaptation between the leaflets creates a leak in the valve.
• In U.S. Pat. No. 6,210,432, a less invasive method is proposed for treating heart valve insufficiency. Here, a method is described for treatment of mitral insufficiency without the need for cardiopulmonary by-pass and opening of the chest and heart. The method uses a device comprising an elongate body having such dimensions as to be insertable into the coronary sinus, which is a vein that substantially encircles the mitral orifice and annulus and drains blood from the myocardium to the right atrium. The elongate body has two states, in a first of which the elongate body has a shape that is adaptable to the shape of the coronary sinus, and to the second of which the elongate body is transferable from said first state assuming a reduced radius of curvature. Consequently, the radius of curvature of the coronary sinus is reduced. Due to the coronary sinus encircling the mitral annulus, the radius of the coronary sinus curvature as well as the circumference of the mitral annulus are reduced by the reduction of the radius of the coronary sinus. Thus, the described method takes advantage of the position of the coronary sinus being close to the mitral annulus, which makes repair possible by the use of current catheter-guided techniques. However, the described method is only useful in diseased valves where the reason for a valvular leak is caused by a dilation of the valve annulus.
• For prolapsing leaflets, catheter-based methods have been presented where the two leaflets of the mitral valve are attached to each other by means of a thread (Percutaneous Edge-to-Edge provided by Edwards Lifesciences Corporation of Irvine, USA) or a clip (Evalve System provided by Evalve, Inc. of USA) creating a double opening with a shape like a bow-tie in the valve.
• In cases where these methods are not useful, the valve may need to be replaced. Percutaneous replacement of heart valves are being developed for the aortic and pulmonary valves by Percutaneous Valve Technologies, Inc., now owned by Edwards Lifesciences Corporation and by CoreValve S.A. of Paris, France. NuMED, Inc. of New York, USA deliver a valve designed by Dr. Bonhoeffer for sole use in the pulmonary valve position. In all these devices, copies of normal human valves with three cusps are sewn from Glutaraldehyde-treated calf or horse pericardium tissue or bovine jugular vein tissue and mounted inside a stent. The stents from Edwards Lifesciences and NuMED are made of stainless steel and need to be dilated by a balloon, whereas the valve from CoreValve is mounted inside a self expanding stent of Nitinol. These devices from Edwards Lifesciences, NuMED and CoreValve will hereinafter be denoted stented valves. The stented valve is placed in the position of the valve it is supposed to replace and dilated, thereby pushing the leaflets and any calcified tissue away and thereby completely eliminating the remaining function of the valve leaflets. However, the stented valves are only useful in circular orifices such as the pulmonary and the aortic valves.
• For the mitral valve and the tricuspid valve, no artificial valve has so far been presented for percutaneous placement. The main reason for not having access to percutaneously implantable valves in the tricuspid and in the mitral valve position is that the valve annulus is oval and the valve opening has a slit-like shape in case of a diseased mitral valve and triangular shape in case of a diseased tricuspid valve. The known stented valves are fixed to the valve annulus by means of friction caused by pressure from the stents towards the surrounding tissue in the valve opening. If the known stented valves with round circumference are introduced into the oval mitral annulus with a leaking area of slit-like shape, there will be wide open areas causing a severe leak, so called paravalvular leak, between the implanted device and the annulus. In addition, the tissue is too weak to allow a good fixation in the tricuspid and mitral orifices. Further, if a known stented valve is introduced in the mitral valve orifice, it would also create a block in the outflow of the aortic valve.
• The known stented valves also have limitations in use for the pulmonary valve. The known stented valves are not suited to be implanted in children or growing juveniles, since they do not permit growths of the valve annulus. However, the most severe drawback with the known stented valves is the size of the device when mounted in delivery systems before implant. Mounting the valve inside a stent creates a huge diameter of the device catheter. The present devices are 7 to 9 mm in diameter, which is a huge diameter considering that the catheter is to be introduced through puncture holes in vessels through the skin and guided through sometimes severely calcified vessels, most of them having the same size as the device, to the target area. The diameter of such devices is half and half caused by the stent and the valve, which each is 3-4 mm thick.
SUMMARY OF THE INVENTION
• It is an object of the invention to provide a device and method for treatment of leaking heart valves, wherein the treatment may be performed on any heart valve. It is a further object of the invention to provide a device and method that may be used without the need for open heart surgery or stopping the heart.
• These and other objects of the invention are accomplished by a blood flow controlling apparatus and a method according to the independent claims.
• Thus, the invention provides a blood flow controlling apparatus, which is configured to be implanted into a blood circulatory system of a patient. The apparatus comprises an anchoring means, which is arranged to fix the position of the apparatus in the blood circulatory system, and a valve means being connected to the anchoring means. The valve means is configured to be arranged within the blood circulatory system and is configured to be extendable in a direction transverse to blood flow in order to make contact with native tissue when inserted in the blood circulatory system. The valve means is further configured to release said contact as a result of being exposed to blood flow in a permitted direction.
• The blood flow controlling apparatus according to the invention may advantageously be used for treating a leaking heart valve. The valve means of the apparatus is arranged to make contact with surrounding tissue for closing the valve and to release the contact for opening of the valve. The valve means may be arranged for making contact with heart valve tissue, such as leaflet tissue. While having contact with the leaflet, an area of coaptation between the valve means and the native leaflet is established. In the area of coaptation, backflow through the valve may be prohibited. The introduction of the valve means in an orifice of a heart valve therefore introduces a further leaflet which cooperates with the native valve leaflets. Thereby, the apparatus is arranged according to an entirely new concept conserving and utilizing the remaining function of the leaflets of the diseased native valve.
• The valve means may be configured to contact tissue in the area of coaptation such that the valve means seals against native tissue to prevent blood flow past the valve means when the valve means extends in the direction transverse to blood flow.
• The feature that the valve means is configured to be extendable in a direction transverse to blood flow should be construed as the valve means being moveable to increase its extension in the direction transverse to blood flow and not necessarily that the valve means will extend entirely in this direction. Thus, the valve means is able to move between a closed state, wherein it extends sufficiently in the direction transverse to blood flow for preventing blood flow past the valve means, and an open state, wherein it extends primarily in a direction along the blood flow.
• Further, the valve means may be oversized such that the valve means is arranged to overlap with native tissue when extending in the direction transverse to blood flow. This strengthens the seal between the valve means and the tissue.
• Since the valve means is arranged to close the leak in a regurgitating heart valve by contacting and overlapping native valve tissue, the apparatus may be applied to a valve of any size and shape. As a matter of fact, the valve means of the apparatus can be oversized to such a degree that it will compensate for continuous deteriorations and shrinking of the native leaflets that is probable to occur especially in rheumatic heart disease. In the same way, an oversized valve means will allow growth of the native vessel or valve when implanted in children or still growing juveniles.
• Although the apparatus has been described above as cooperating with valve tissue, it is contemplated that the apparatus may alternatively be arranged such that the valve means makes contact with an inner wall of a vessel in which it is inserted, such as to introduce a valve function within a vessel.
• The apparatus may appropriately be inserted through the vascular system into a body and advanced to the heart or the great vessels close to the heart and to be subsequently deployed in or adjacent to the native heart valve in order to treat any leak in a heart valve. Thus, there is no need for opening the chest, stopping the heart or cutting or treating of the native valve tissue with advanced or demanding methods.
• The valve means may present a contact surface comprising a contact area to make contact with native tissue, wherein the contact surface is arranged to extend such as to face blood flow from the permitted direction. Thus, blood flow from the permitted direction will hit the contact surface, providing a force on the valve means. This will press the valve means to release contact with tissue and allow blood flow past it.
• The apparatus may further comprise a spacer for providing a distance between the anchoring means and the valve means. The spacer may be arranged in the form of an elongate connecting means which connects the anchoring means to the valve means and provides an axial spacing between the anchoring means and the valve means. Consequently, the apparatus separates the valve means from the anchoring means, providing a small diameter of the apparatus, since the diameter of the anchoring means is not superposed on the diameter of the valve means. The diameter of the apparatus may typically be 3-4 millimetres. This is very useful for introduction of the apparatus, since it may be introduced through a small puncture hole into the body. This makes the surgical procedure less invasive. Further, the anchoring means will not be arranged in the orifice of the native valve, whereby a much larger valve opening is permitted and blood flow is facilitated through the valve.
• The valve means may be attached to the connecting means as to strive towards extending in the transverse direction to the connecting means. This implies that the valve means has an inherent strive towards making contact with a valve leaflet or a vessel wall when implanted in the patient. The valve means will then need to be exposed to a force to prevent extending in the transverse direction. Such force may be provided by blood flow in the allowed direction. As a result, the function of the valve means to allow blood flow in a forward direction and prevent blood flow in a backwards direction may be accomplished by the inherent strive. Thus, no outside control of the valve means will be needed to achieve this function. In fact, the valve means may be arranged such that blood flow in the backwards direction pushes the valve means towards the native heart valve leaflets or a vessel wall to make contact with the valve leaflets or vessel wall. Thus, backflow may initially aid in extending the valve means in the transverse direction.
• The valve means may be arranged on the connecting means. According to one embodiment, the valve means is arranged symmetrically around the connecting means. This implies that the valve means will act identically around the circumference of the connecting means in order to close against the native valve leaflet or the vessel wall. As a result, the placement of the connecting means and the anchoring means is not very critical for ensuring that the valve means will completely seal blood flow through the valve or the vessel by making contact with the native valve leaflet or the vessel wall over its entire circumference. Further, as mentioned above, the valve means may be over-sized such that the diameter of the valve means, when extending transversely to the connecting means, is larger than the jet of leaking blood or larger than the diameter of the vessel in which it is placed. This ensures that the valve means will seal the vessel properly when making contact with the vessel wall, even when the connecting means is not exactly centrally positioned in the valve or the vessel. However, the apparatus may be designed such that at least part of the connecting means is flexible allowing the valve means to center itself to the center of the blood flow.
• The valve means may in its open state be configured to have a larger extension along the direction of blood flow than a native valve in its open state. This implies that the valve means may be arranged to reach and make contact with native valve leaflets that are extending to abnormal positions. This ensures that a coaptation will be achieved also to areas of the native valve that are prolapsing towards the atria, a situation that often occurs in diseases with redundant native valve material. Also, coaptation will be achieved with leaflets restrained by shortened chordae tendinae.
• The valve means may comprise a flap, which is moveable between an open position where it extends along the connecting means and a closed position where it extends in a transverse direction to the connecting means.
• The flap may comprise an attachment end, which forms an attachment of the flap to the connecting means in a longitudinal position of the connecting means. The flap may further comprise a contact end, which is arranged to make contact with native tissue. The flap may be hingedly moveable around the attachment position between its open position and closed position, where the contact end makes contact with tissue.
• The contact end may be connected to the connecting means by means of control strings. The control strings may prevent the flap from turning over to extend along the connecting means in the opposite longitudinal direction. If the flap would turn over, no contact with the native valve or the vessel wall would occur, and consequently blood may regurgitate through the valve means.
• The flap may form an attachment to the connecting means extending along a longitudinal direction of the connecting means. The flap will then have a secure attachment to the connecting means to avoid the need of control strings for preventing the flap to be turned over.
• The sealing of the valve means to the native valve leaflet or the vessel wall may be accomplished by various embodiments. In one embodiment, the flap extends around the entire circumference of the connecting means. The flap may be homogenous or comprise several subsections, which may form an umbrella- or parachute-like shape.
• In another embodiment, the valve means comprises several flaps. The flaps may overlap each other to properly seal the valve or vessel when extending to make contact with the native valve leaflet or the vessel wall. Thus, no backflow is allowed between the flaps. As an alternative, adjacent flaps may tightly contact each other to prevent leakage between the flaps.
• The flaps may be strengthened at an end which is attached to the connecting means. The strengthened base may act to prevent the flaps from turning over.
• The flap or flaps may preferably be made of biological tissue, such as animal tissue treated with Glutaraldehyde or similar solutions. The animal tissue may originate from heart valve, blood vessels or pericardial tissue, which is normally used for producing artificial biological heart valves. However, the flaps may also or alternatively be made of a synthetic material, such as polyurethane, polyvinyl or polytetrafluoroethylene (PTFE), or a shape memory material, such as Nitinol or shape memory polymers.
• One advantageous feature of the blood flow controlling apparatus is the anchoring means for fixing the position of the apparatus in the blood circulatory system. The anchoring means prevents migration of the valve means away from a correct position inside a heart valve or a vessel. During systole of the heart rhythm, there is a high pressure gradient between ventricle and atrium and, during diastole of the heart rhythm, there is a high pressure gradient between the aorta and left ventricle and between the pulmonary artery and the right ventricle. Therefore, a strong fixation of the apparatus is needed to avoid migration of the valve means.
• Depending on the fixation site for the anchoring means, the valve means may be arranged on either side of the anchoring means such that the allowed blood flow may be directed from the anchoring means to the valve means or vice versa.
• Further, depending on the fixation site in the blood circulation system of the patient, there are a number of embodiments for the anchoring means. The valve means may be arranged to be placed at a mitral valve, a tricuspid valve, a pulmonary valve or an aortic valve. The apparatus may therefore be used to treat a leak in any of these valves. Alternatively, the valve means may be arranged in an arterial vessel or a venous vessel for introducing a valve function in the artery or the vein, which may replace the function of a diseased heart valve. The anchoring means may be arranged to engage an arterial vessel wall, a venous vessel wall, the atrial septum, the interventricular muscular septum, a muscular ventricular wall, or an atrial wall. The anchoring means is fixed in a position that is suitable for the placement of the valve means.
• The anchoring means may comprise an expandable element for engaging wall tissue. This implies that the anchoring means fixes the position of the apparatus by securing the apparatus to wall tissue. The expandable element may be tube-shaped. The anchoring means may then be used to fix the position of the apparatus to a wall of a vessel by engaging the vessel wall along the entire circumference of the tube-shaped element. The anchoring means may be arranged to fix the position of the apparatus to a vessel in or adjacent to the heart where the valve means is to be arranged in a regurgitating heart valve. The expandable element may be a stent forming a tube from a mesh of struts. The expandable element may be a conventional vascular stent, which is normally used for supporting vessel walls during dilation treatment of vascular disease.
• The connecting means is attached to the anchoring means for connecting the valve means to the anchoring means. The connecting means may e.g. be connected to either end of the anchoring means, such as to extend through the anchoring means towards the valve means or as an extension from the anchoring means towards the valve means. The connecting means may be attached to one or more, preferably two, stent struts. Preferably, the attachment is a seamless continuation of the strut material into the connecting means. Such attachment could be achieved if the anchoring means and the connecting means are constructed out of the same piece of material, for instance by laser cutting. Otherwise, the attachment could be made by means of welding.
• The expandable element may alternatively comprise a plurality of springs arranged to engage with opposite sides of a wall of a heart atrium. The anchoring means may thus fix a position inside a heart atrium by engaging opposite walls of the heart atrium.
• In an alternative embodiment, the anchoring means comprises a disk-shaped element, which is arranged for engaging a tissue wall. In this embodiment, the valve means and the disk-shaped element of the anchoring means are arranged on opposite sides of the tissue wall and the connecting means extends through the tissue wall. The position is fixed by the disk-shaped element abutting and engaging the tissue wall.
• The anchoring means may comprise another disk-shaped element and wherein the disk-shaped elements are connected by a penetration part for engaging opposite sides of a tissue wall. In this embodiment, the disk-shaped elements fix the position of the apparatus by abutting and engaging opposite sides of the tissue wall.
• The anchoring means comprising one or more disk-shaped elements may be used for fixation to e.g. the interatrial septum or another heart wall, where the valve means is to be arranged in the mitral or tricuspid valve.
• According to a further alternative embodiment, the anchoring means comprises hooks arranged for penetrating wall tissue. Such an anchoring means may also be used for fixation to e.g. the interatrial septum or another heart wall, where the valve means is to be arranged in the mitral or tricuspid valve.
• According to another alternative embodiment, the anchoring means comprises a plurality of arms arranged for engaging chordae tendinae. According to yet another alternative embodiment, the anchoring means comprises clips arranged for engaging papillary muscles. These embodiments of the anchoring means may also be used for fixation to e.g. the interatrial septum or another heart wall, where the valve means is to be arranged in the mitral or tricuspid valve.
• The anchoring means may be made of a shape memory material, such as Nitinol or a shape memory polymer. This implies that the anchoring means may be self-expandable to assume its preprogrammed shape. However, ordinary stainless steel, stainless spring steel or any other metal might be used. The connecting means would preferably be made of similar material as the anchoring means.
• The apparatus may comprise two connecting means extending from the anchoring means in different directions, wherein valve means are attached on each connecting means. The apparatus may then be used for treating two malfunctions in the body simultaneously. For example, the apparatus may be arranged such that one valve means is placed in the mitral valve and one valve means is placed in the tricuspid valve for simultaneous treatment of these valves. The anchoring means may comprise two disk-shaped elements arranged to engage opposite sides of the interatrial septum or the interventricular septum and connecting means may extend in opposite directions from the anchoring means towards the mitral and tricuspid valves, respectively.
• The connecting means may be arranged to assume a programmed shape within the blood circulatory system. In this case, the connecting means may be made of a shape memory material, e.g. Nitinol, allowing the connecting means to be straight during insertion and to resume a pre-programmed, curved shape exactly fitting the calculated track from the fixation point to the correct position of the valve means. This facilitates insertion and placing of the apparatus in the blood circulatory system.
• In an alternative embodiment, the connecting means comprises a plurality of segments arranged in sequence, wherein the interrelationship between adjacent segments is controllable. This implies that the connecting means may be designed in a very flexible manner by the segments being able to flexibly move in relation to each other. The connecting means may thus e.g. allow an operator to manipulate it for centering the valve means in a stream of blood created by the leak in the native valve.
• The connecting means may further comprise a locking mechanism for locking the position of adjacent segments to each other. Thus, when placed in an appropriate position, each segment may then be locked to each other for fixating the shape of the connecting means and thus the position of the valve means. The locking mechanism may comprise a tension wire arranged extending through the sequential segments. The wire may be locked under tension for fixating the shape of the connecting means. The locking mechanism may further comprise a tap for engaging the tension wire to lock the form of the tension wire through the sequential segments. Thus, the tap locks the wire under tension to fix the shape of the connecting means.
• The connecting means may have a longitudinal groove or channel for receiving a guide wire. The connecting means may e.g. be tubular or U-shaped for allowing a guide wire to pass through the connecting means. This implies that the connecting means may be introduced into the patient by sliding over a guide wire.
• The connecting means may further comprise a disengaging means for releasing the valve means from the anchoring means. This implies that a valve means, which may have lost its treating function over time, may be replaced without the need to replace the entire apparatus.
• According to another aspect of the invention, there is provided a kit for controlling blood flow in a blood circulatory system of a patient. The kit comprises a blood flow controlling apparatus as described above and a delivery system for carrying the blood flow controlling apparatus to a desired position in the blood circulatory system.
• The kit may provide a package to a surgeon who is about to introduce a blood flow controlling apparatus into a patient. Thus, the kit provides both an implant which may be used for treating the patient and a delivery system which may be used for inserting the implant.
• The anchoring means of the blood flow controlling apparatus may be mounted in the delivery system during storage, whereas the valve means of the blood flow controlling apparatus may be mounted in a container with appropriate storage fluid. Where the valve means is made of biological material, it will need to be stored in a storage fluid in order not to be destroyed during storage. The valve means may be arranged such that the operator may pull the valve means inside the delivery system just prior to insertion into the patient.
• The valve means may be disconnected from the anchoring means during storage. This implies that the valve means is stored in a separate container and may be attached to the rest of the blood flow controlling apparatus just prior to insertion into the patient.
• The kit may further comprise a guide wire for guiding insertion of the delivery system to the desired position through the vascular system of the patient. The delivery system may also comprise a guiding catheter which is arranged to be pushed over the guide wire to the desired position. Thus, the blood flow controlling apparatus may be inserted to the desired position through the vascular system of the patient.
• According to a further aspect of the invention, there is provided a method for controlling blood flow in a blood circulatory system of a patient. The method comprises inserting an artificial valve means to a desired position in the blood circulatory system; arranging the artificial valve means in the desired position such that the valve means extends in a direction transverse to blood flow for making contact with heart valve tissue or vessel wall tissue and the valve means releases said contact when being exposed to blood flow in a permitted direction; and fixing the position of the artificial valve means by attaching an anchoring means in the blood circulatory system, said anchoring means being connected to the artificial valve means at an axial distance therefrom. The implanted artificial valve means may thus block backflow in a leaking heart valve and allow only forward flow in the valve. The anchoring means may be arranged at an axial distance from the valve means provided by an elongate spacer. Consequently, the valve means is spaced from the anchoring means, enabling insertion into the blood circulatory system through a small diameter, since the diameter of the anchoring means is not superposed on the diameter of the valve means.
• The inserting may be performed through the vascular system by means of a catheter. According to this method, the valve means may be inserted and fixated by means of an instrument being inserted through the vascular system of a patient providing a low-invasive treatment method that only requires a needle puncture of the skin, thereby getting access to the vascular system, without the need of any surgery or anaesthesia. The access to the vascular system may be achieved through the venous or arterial system of the patient.
• As an alternative, the valve means may be inserted and fixated through a small surgical access from outside the chest, entering the pericardial space and inserting the apparatus through the ventricular or atrial wall by guidance of direct vision and/or x-ray and ultrasound imaging.
• As another alternative, the valve means may be inserted and fixated thoracoscopically, by means of an endoscope or a surgical robot, using an access from outside the chest, entering the pericardial space and inserting the device through the ventricular or atrial wall by guidance of vision through the endoscope or the robot equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention will now be described in further detail by way of example under reference to the accompanying drawings.
• FIG. 1 is a schematic view of a partial cross-section of the heart indicating its general anatomy.
• FIG. 2ais a schematic view of a blood flow controlling apparatus according to a first embodiment of the invention with a valve means of the apparatus being in an open state allowing blood flow.
• FIG. 2bis a schematic view of a blood flow controlling apparatus according to a first embodiment of the invention with a valve means of the apparatus being in a closed state preventing blood flow.
• FIG. 2cshows different cross-sections of the blood flow controlling apparatus in expanded and compressed states.
• FIGS. 3a-3dare schematic views of the blood flow controlling apparatus showing different embodiments of an expanding element for anchoring the apparatus.
• FIGS. 4a-4fare schematic views of the blood flow controlling apparatus showing other embodiments of an anchoring means.
• FIG. 4gis a schematic view of a blood flow controlling apparatus comprising two anchoring means.
• FIGS. 5a-iare schematic views of a connecting means of the blood flow controlling apparatus.
• FIG. 5jis a schematic view of a connecting means providing detachment of the valve means from the anchoring means.
• FIGS. 6a-care schematic views of different embodiments of a valve means of the blood flow controlling apparatus.
• FIGS. 7a-fare views of a further embodiment of the valve means.
• FIGS. 8a-fare schematic views of a mitral valve indicating a valve means of a blood flow controlling apparatus according to the invention being inserted for treating a leak in the mitral valve.
• FIGS. 9a-care schematic views of a tricuspid valve indicating a valve means of a blood flow controlling apparatus according to the invention being inserted for treating a leak in the tricuspid valve.
• FIGS. 10a-cshow a blood flow controlling apparatus being inserted in the aorta for treatment of a leaking aortic valve.
• FIGS. 11a-dshow different embodiments of a blood flow controlling apparatus being inserted in the pulmonary artery.
• FIG. 12 shows blood flow controlling apparatuses being inserted in the superior vena cava and the inferior vena cava.
• FIGS. 13a-kare schematic views of a heart showing different embodiments of the blood flow controlling apparatus being inserted in the mitral valve and tricuspid valve, respectively.
• FIGS. 14a-hare schematic views showing a delivery system carrying and releasing the blood flow controlling apparatus.
• FIGS. 15a-20eare schematic views illustrating methods for inserting the blood flow controlling apparatus into a patient.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
• Referring toFIG. 1, the general anatomy of aheart1 will be described. Blood is lead through thesuperior vena cava2 and theinferior vena cava4 into theright atrium6 of theheart1. Thetricuspid valve8 controls blood flow between theright atrium6 and theright ventricle15. Thetricuspid valve8 is closed when blood is pumped out from theright ventricle15 to the lungs. During this period, blood is filled into theright atrium6. Thereafter, thetricuspid valve8 is opened to fill theright ventricle15 with blood from theright atrium6. Free edges of leaflets of thetricuspid valve8 are connected viachordae tendinae10 topapillary muscles12 for controlling the movements of thetricuspid valve8. Blood from theright ventricle15 is pumped through thepulmonary valve20 to thepulmonary artery22 which branches into arteries leading to each lung. Blood from the lungs are lead throughpulmonary veins28 into theleft atrium26 of theheart1. Themitral valve30 controls blood flow between theleft atrium26 and theleft ventricle17. Themitral valve30 is closed when blood is pumped out from theleft ventricle17 to theaorta34 and the arteries of the body. During this period, blood is filled into theleft atrium26. Thereafter, themitral valve30 is opened to fill theleft ventricle17 with blood from theleft atrium26. Free edges of leaflets of themitral valve30 are connected via chordae tendinae11 topapillary muscles13 for controlling the movements of themitral valve30. Blood from theleft ventricle17 is pumped through theaortic valve32 into theaorta34 which branches into arteries leading to all parts of the body.
• The function of theheart1 may be impaired by any of the heart valves not functioning properly. The heart valves may lose their ability to close properly due to e.g. dilation of an annulus around the valve or a leaflet being flaccid causing a prolapsing leaflet. The leaflets may also have shrunk due to disease, e.g. rheumatic disease, and thereby leave a gap in the valve between the leaflets. The inability of the heart valve to close will cause a leak backwards, so called regurgitation, through the valve, whereby the function of theheart1 will be impaired since more blood will have to be pumped through the regurgitating valve.
• Referring now toFIGS. 2a-2c, anapparatus42, which may be used in treatment of a regurgitating heart valve, will be generally described. Theapparatus42 is arranged to be implanted into a patient for providing a permanent or at least long-term treatment. Theapparatus42 comprises a valve means52, which is transferable between an open state, as shown inFIG. 2a, allowing blood flow past the valve means52, and a closed state, as shown inFIG. 2b, preventing blood flow past the valve means52. The valve means52 is arranged to make contact with surrounding tissue in its closed state for sealing a blood flow path. As illustrated inFIGS. 2a-b, the valve means52 has a greater radial extension in the closed state than in the open state for making contact with tissue. The valve means52 will release the contact in its open state to allow blood flow, wherein the valve means52 in its open state will be arranged within the path of the blood flow. Different embodiments of the valve means52 will be described in further detail below with reference toFIGS. 6-7.
• Theapparatus42 further comprises an anchoring means54. The anchoring means54 is arranged to fix the position of theapparatus42 in a patient. The anchoring means54 is arranged to engage with tissue for fixing the position of theapparatus42. Different embodiments of the anchoring means54 will be described in further detail below with reference toFIGS. 3-4.
• The apparatus further comprises a connectingmeans46, which connects the valve means52 with the anchoring means54. The connecting means46 provides a spacing between the anchoring means54 and the valve means52. This implies that theapparatus42 may be arranged in an elongate form and may be arranged in a small diameter. This facilitates insertion of theapparatus42 into the patient, since theapparatus42 may be inserted through a small incision. InFIG. 2c, the cross-section of theapparatus42 at the anchoring means54 and at two positions in the valve means52 are shown below a side view of theapparatus42. The cross-section of theapparatus42 when implanted is shown immediately below the view of theapparatus42. Further below, the cross-section of theapparatus42 when compressed during insertion is shown. The valve means52 and the anchoring means54 are inserted in sequence and therefore the diameter of the device will not be an accumulation of the diameters of the valve means52 and the anchoring means54. Instead, theapparatus42 may be compressed to a very small diameter as shown inFIG. 2c. Further, the connectingmeans46 provides a possibility to fix the position of the valve means52 by the anchoring means54 engaging an appropriate site in the vicinity of the desired position of the valve means52. The anchoring means54 is not intended to engage tissue at the exact positioning of the valve means52. The connecting means46 also provides a surface or position, to which the valve means52 is attached.
• Theapparatus42 is arranged to be inserted in a minimally invasive manner into the patient. Theapparatus42 may be inserted endoscopically through a small diameter or be guided through the vascular system of the patient by means of a catheter-based technique. In the latter case, theapparatus42 may be introduced into the vascular system through a puncture in e.g. the groin or the neck of the patient. Theapparatus42 may be held in a compressed state during insertion for providing as small diameter as possible of theapparatus42. Further, theapparatus42 may comprise a channel or groove for receiving a guide wire through theapparatus42, such that theapparatus42 may be guided to the correct position sliding on the guide wire.
• Referring now toFIGS. 3-4, different embodiments of the anchoring means will be described. The anchoring means may be realised in any manner providing engagement with tissue for fixing the position of the apparatus. The anchoring means may thus comprise hooks, barbs, spikes or any other means for engaging with or partially or wholly penetrating a tissue portion. The anchoring means may also or alternatively comprise an element which is arranged for contacting a tissue portion for fixing the position. This element may be accomplished in a tubular or ring-like form for engaging an inner wall of a structure in the blood circulatory system, such as a vessel wall or an atrium wall. The element engages the inner wall to create contact along a circumference of the element. Preferably, the element is pushed towards the inner wall by an internal strive to expand its radius. The anchoring means may, as a further alternative, be arranged to contact a tissue portion at an opposite side of a tissue wall to the position of the valve means. The anchoring means may thus form a contact surface with the tissue portion which is larger than a penetration hole through the tissue portion for fixing the position of the apparatus.
• As shown inFIG. 3a-c, the anchoring means54 may comprise a tubularexpandable element55, which is arranged to make contact with a blood vessel wall along its circumference. Thetubular element55 may be a stent. Thestent55 may be self-expandable having an internal strive to expand into contact with the vessel wall. Alternatively, thestent55 may be expanded by means of an external force, such as an inflation of a balloon from inside thestent55. Thestent55 may be formed of threads or struts that constitute a zig-zag pattern. Thestent55 may be inserted into the patient in a compressed shape having a small radius and be expanded when placed in the desired position. As shown inFIG. 3a, the connecting means46 branches into twoarms58 which are attached to diametrically opposite positions of thestent55. As shown inFIG. 3b, the connecting means146 may alternatively branch into twoarms158 which are attached to struts of thestent55 which are close to each other or immediately adjacent each other. Further, as shown inFIG. 3c, the connecting means246 may be arranged to assume a prebent shape such as to provide a connection between an anchoring means54 and a valve means52, which are not to be placed in line with each other within the patient. The connecting means246 may alternatively be flexible such that it may be forced to a desired shape within the patient by using e.g. a preshaped catheter. As a further alternative, the connecting means246 may be flexible such that it centers itself within the blood flow in which it is located.
• As shown inFIG. 3d, the anchoring means154 may alternatively comprise a plurality of threads or struts155 that are resilient or spring-like such that they have an inherent strive towards assuming a shape having contact with an inner wall of an atrium over a substantial length of thethread155. Thethread155 may be elliptic or circular for contacting the atrium wall. The anchoring means154 may comprise a plurality ofthreads155 such that a large contact area is created with the atrium wall. Thethreads155 may be symmetrically distributed such that contact is symmetrically achieved with the atrium wall.
• InFIGS. 3a-d, the anchoring means is arranged on an “inflow” side of the valve means, that is the valve means permits blood flow from the direction of the anchoring means past the valve means. This is suitable when the valve means is to be arranged in the mitral or tricuspid valve and the anchoring means is to be arranged in a blood vessel or a heart atrium for fixing the position of the apparatus. The embodiments of the anchoring means shown inFIGS. 4a-f, which will be described further below, are arranged on an “outflow” side of the valve means, that is the valve means permits blood flow past the valve means towards the anchoring means. This is suitable e.g. when the valve means is to be arranged in the mitral or tricuspid valve and the anchoring means is arranged to fix the position of the apparatus by engaging ventricular tissue.
• As shown inFIG. 4a, the anchoring means254 may comprise a disk-shapedelement255 to be arranged in contact with a heart wall portion, such as a ventricular wall or interventricular septum. The connecting means46 will extend through the heart wall and the disk-shapedelement255 will prevent the anchoring means254 from migrating through the heart wall. The anchoring means254 may further comprise a hook, barb or the like for engaging the heart wall. The disk-shapedelement255 may be compressed for insertion through the heart wall and may assume its disk-shape when a compressing force is released.
• As shown inFIG. 4b, the anchoring means354 may comprise two ormore hooks355 for engaging chordae tendinae. The connecting means346 branches off into essentially transversal branches extending to the respective hooks355. Thehooks355 are arranged to capture chordae tendinae within thehooks355 for fixing the position of theapparatus42.
• As shown inFIG. 4c, the anchoring means454 may comprise a plurality ofclips455 for engaging papillary muscles. Theclips455 are arranged to grab around the papillary muscles for fixing the position of theapparatus42. Again, the connecting means446 branches off into branches extending transversally and even backwards to one ormore clips455, respectively.
• As shown inFIG. 4d, the anchoring means554 may comprise a plurality of disk-shaped or bar-shapedelements555 arranged to engage a valve annulus. The connecting means546 branches off into branches extending backwards such that the anchoring means554 may be arranged in engagement with a valve annulus where the valve means52 is arranged in the valve. The engagement with the valve annulus may be accomplished by two disk-shaped or bar-shapedelements555 engaging opposite sides of the annulus. The anchoring means554 may then further comprise aconnection557 between the disk-shapedelements555, wherein theconnection557 is arranged to extend through the valve annulus. Theconnection557 may further compriseprojections559, which may be used for fixing the position of one of the disk-shapedelements555 along theconnection557. The disk-shapedelement555 may then be pushed or forced over theprojection559 and be held in this position. Thus, the distance between the two disk-shapedelements555 is adjustable to fit the thickness of the valve annulus and to thereby attach the apparatus to the valve annulus.
• As shown inFIGS. 4e-f, the anchoring means arranged on an “outflow” side of the valve means may comprise astent55 as described above with reference toFIGS. 3a-c. As shown inFIG. 4e, the connectingmeans46 may branch into twoarms58 which are attached to diametrically opposite positions of thestent55 and are attached to an end of thestent55 which is closest to the valve means52. As shown inFIG. 4f, the twoarms58 of the connectingmeans46 may alternatively be attached to an end of thestent55 which is farthest away from the valve means52. This embodiment may be arranged in a very compact form with the valve means52 being arranged close to the anchoring means54.
• As shown inFIG. 4g, theapparatus42 may comprise two anchoring means54,254, which are arranged on an “inflow” and “outflow” side of the valve means52, respectively. The two anchoring means54,254 may cooperate to securely fix the position of theapparatus42 within the patient.
• The anchoring means may be made of a shape memory material, such as Nitinol or a shape memory polymer. This implies that the anchoring means may be self-expandable to assume its preprogrammed shape. This is especially suitable where the anchoring means comprises an element to be expanded within the patient. However, ordinary stainless steel, stainless spring steel or any other metal might be used. The connecting means could be made of similar material as the anchoring means. The connecting means may then be an extension of the anchoring means without the need of any welding or attachment point between the connecting means and the anchoring means.
• The connecting means may be realised as an elongate body providing a spacer and connection between the valve means and the anchoring means. The connecting means may have branches for extending to different parts of an anchoring means in order to provide a more secure connection between the anchoring means and the connecting means or in order to create a connection between separate anchoring means. The connecting means may e.g. have a round or flat cross-section. The connecting means may be tubular or have a groove, e.g. U- or C-shaped, for receiving a guide wire during insertion of theapparatus42. The connecting means may alternatively be formed from a solid material. The connecting means may as a further alternative be made of threads or struts forming a grid of zig-zag or scissor-shaped thin material. The connecting means may still be hollow or present a groove while being shaped as a grid. The connecting means may be arranged in a flexible material or in a shape memory material such that the connecting means may be fitted to a specific track after being inserted in the body. As a further alternative, the connecting means may be formed from a plurality of sequentially arranged segments, whose mutual relationship may be controlled or adjusted.
• Referring now toFIGS. 5a-i, a segment-based embodiment of the connecting means will be described. InFIG. 5a, anapparatus42 is shown with a connectingmeans46 being arranged between the anchoring means54 and the valve means52. InFIG. 5b, a portion of the connecting means46 marked with circle B inFIG. 5a, is shown in greater detail. The connecting means46 comprises sequential connectingsegments100. InFIG. 5c, two connectingsegments100 are indicated in even greater detail. The connectingsegments100 comprise ahead102, which may e.g. be spherically shaped, and anend104 with arecess105 corresponding to the shape of thehead102, such that therecess105 may receive ahead102. Therecess105 is slightly larger than thehead102 to allow thehead102 to be rotated within the recess for adjusting the mutual relationship ofadjacent segments100. Thehead102 comprises a small protrusion orknob106 and theend104 comprises a small notch108 for receiving theprotrusion106. When theprotrusion106 is positioned in the notch108, thesegments100 are aligned. Theprotrusion106 may be pushed out of the notch108 by applying a small force to the connectingmeans46. There may bemultiple protrusions106 and notches108 on thehead102 and end104, respectively, so that thehead102 and end104 may engage in multiple different relationships in order to lock the connectingsegments100 in different desired angles. Thesegments100 further comprise achannel110 for receiving a locking wire. By locking the shape of the locking wire when extending through thesegments100, the mutual relationships of thesegments100 is locked, as will be further described below. InFIG. 5d, afront segment113 of the connectingmeans46 is shown. Thefront segment113 comprises anend104 similar to theends104 of theother segments100. Thefront segment113 comprises ablind bore114 in itsend104. Thelocking wire112 is received in theblind bore114 and attached to thefront segment113 within thebore114. Thefront segment113 provides a non-flexible part of the connectingmeans46 and may have a longer longitudinal extension than theother segments100. Thefront segment113 is arranged at the end of the connecting means46 closest to the valve means52.
• InFIG. 5e, arear segment116 of the connectingmeans46 is shown. Therear segment116 comprises ahead102 similar to theheads102 of theother segments100. Therear segment116 also comprises achannel110 for receiving thelocking wire112. Therear segment116 also comprises at its end alocking mechanism101 for locking the shape of thelocking wire112. Therear segment116 also comprises welding orfixation points118 for attaching therear segment116 to the anchoring means54 or toarms58,158 or branches of the connectingmeans46, which in turn are attached to the anchoring means54.
• Thelocking mechanism101 will now be further described with reference toFIGS. 5f-h. InFIG. 5f, the parts of thelocking mechanism101 are shown. The locking mechanism comprises anarm120, which is a rotatably attached to theend segment116 in arotation point122. Thearm120 may be attached to theend segment116 by means of a pin extending through a hole in thearm120 and engaging theend segment116. Thearm120 has aprotrusion124, which may be rotated into engagement withgrooves126 in thelocking wire112. Theprotrusion124 may be e.g. wedge-shaped as shown inFIG. 5f. Anadjustment wire128 may be attached and detached to thelocking wire112. Theadjustment wire128 may be arranged to extend outside the patient for providing control of the position of thelocking wire112 from outside the patient during insertion of theapparatus42. Thelocking wire112 and theadjustment wire128 may comprise correspondingnotches133,134 andgrooves130,132 for providing an attachment between the wires. Operation of thelocking mechanism101 is shown inFIGS. 5g-h. Theadjustment wire128 is arranged in afixation tube136, which covers the attachment between theadjustment wire128 and thelocking wire112 for preventing detachment of the wires. When thefixation tube136 is pulled backwards or withdrawn from the patient, theadjustment wire128 can be detached from thelocking wire112. InFIG. 5g, the lockingarm120 is shown in engagement with thelocking wire112 locking the shape of thelocking wire112. As shown inFIG. 5h, thefixation tube136 can also be moved forward to rotate thelocking arm120, so that the wedge-shapedprotrusion124 is forced out of thegroove126 and thereby the lock is opened. The mutual relationships of thesegments100 of the connecting means46 can then be adjusted again. When thelocking wire112 is stretched and locked instead, the friction between the spherical-shapedrecess105 in a segment and thehead102 of the adjacent segment will fix the segments in a certain position relative to each other.
• Orientation of thesegments100 in relation to each other may in one embodiment, as shown inFIG. 5i, be made by means of apreshaped catheter135 that force thesegments100 to line up according to the shape of thecatheter135 before thesegments100 are locked relative to each other. Thecatheter135 may have any shape to mimic the desired track of the connectingmeans46. Thecatheter135 may have a shape memory such that thecatheter135 may be activated to assume its shape when theapparatus42 has been fixed in the body.
• Another embodiment for orientating thesegments100 in relation to each other is to attachthreads135′ to thesegments100. By pulling in thethreads135′, at least onesegment100 can be steered to the correct position. When allsegments100 have been correctly placed, thesegments100 may be locked relative to each other. Thethread135′ may be double forming a loop that engages a hook or loop on thesegment100. When the steering is completed, thethread135′ may be pulled out.
• As shown inFIG. 5j, the connectingmeans46 may provide a possibility to disengage the valve means52 from the anchoring means54. The valve means52 may in time suffer structural damage or calcification and may therefore need to be replaced. By disengaging the implanted valve means52, there is only a need to replace the valve means52. The connecting means46 may therefore comprise alock137 for enabling detachment of the valve means52 from the anchoring means54. Where an embodiment of the connecting means46 as shown inFIGS. 5a-jis used, thelock137 may e.g. be provided in the front segment103. InFIG. 5j, thelock137 is enlarged showing one possible embodiment. Thelock137 has amale portion138 with a threaded winding139, which is fitted into afemale portion140 with a threadedgroove141. Thus, themale portion138 may be screwed on or off thefemale portion140 for engaging or releasing the lock. It should be appreciated that numerous other embodiments of the lock are possible. For example, the lock may be formed from a hook engaging a loop or a pin engaging a bore.
• Referring now toFIGS. 6-7, different embodiments of the valve means will be described. Generally, the valve means is arranged to seal the native heart valve or blood vessel in which it is placed in order to prevent backflow in the valve or the vessel. The valve means is therefore oversized so that it will certainly contact and seal against the leaflets of the native valve or against the wall of the vessel. The valve means will further provide a surface facing forward flow in the native heart valve or the vessel, wherein the surface is arranged in such a manner that when exposed to blood flow in the forward direction, the blood flow will force the valve means to open.
• According to a first embodiment shown inFIG. 6a, the valve means52 comprises aflap44 which symmetrically encircles the connectingmeans46. Theflap44 is attached to the connecting means46 around its entire circumference in alongitudinal attachment point90 forming a fluidtight attachment around the connectingmeans46. Theflap44 is hinged in theattachment point90 such that it is moveable between an open position where it extends mainly along the connectingmeans46 and a closed position, as shown inFIG. 6a, where it extends in a mainly transverse direction to the connectingmeans46. Theflap44 has acontact surface92 which faces the forward flow in the native heart valve or the vessel and which is arranged to contact the leaflets of the native heart valve or the vessel wall in the closed position of theflap44. When moving into the closed position, theflap44 will move towards increasingly extending in a transverse direction to the connectingmeans46. Thecontact surface92 will then come into contact with the leaflets of the native heart valve or the vessel wall before theflap44 extends in a fully transverse direction to the connectingmeans46. Theflap44 will therefore contact the leaflets of the native heart valve or the vessel wall in acoaptation area94 of thecontact surface92 corresponding to a short distance along the leaflets of the native heart valve or the vessel and the boundary of thecoaptation area94 forming a closed circumferential shape such that coaptation is achieved around the entire valve means52. This oversizing of theflap44 also implies that the connectingmeans46 will not need to be precisely centrally positioned in the native heart valve or the vessel.
• Thecontact surface92 has arim96 at the end which comes in contact with the leaflets of the native heart valve or the vessel wall. Therim96 is strengthened byenforcement strings53 connecting therim96 with afixation point98 on the connectingmeans46. The enforcement strings53 stabilize the shape of theflap44 in the closed position. The enforcement strings53 may be an integrated part of theflap44 or they may be attached to theflap44 by e.g. gluing or a knot. The enforcement strings53 also prevent theflap44 from turning over, i.e. to extend in the opposite direction along the connecting means46 from theattachment point90. If theflap44 would turn over it would no longer function to allow forward flow nor preventing backflow past the valve means52.
• Theflap44 of the valve means52 has an internal strive to assume the shape of the closed position. When inserted and released from a restraining cover, the valve means52 will open like a parachute, make contact with the leaflets of the native heart valve or the vessel wall and form a valve that only allows flow in one direction.
• The second embodiment of the valve means is shown inFIG. 6b. This valve means152 comprises aflap144, which is divided intosubsections145 by means of flap enforcement parts147. This gives the flap144 a more stable umbrella-like or parachute-like shape and therefore fewer enforcement strings153 are needed. In fact, the enforcement strings153 may be completely omitted if the flap enforcement parts147 are sufficiently strong or rigid to prohibit a turning over of theflap144. The enforcement strings153 are attached to theflap144 at the interface between twoadjacent subsections145 and connect theflap144 to afixation point198. As for the first embodiment, theflap144 is attached symmetrically around anattachment point190 of the connectingmeans46 and provides a contact surface192 with acoaptation area194.
• In the third embodiment shown inFIG. 6c, the valve means252 comprisesseveral flaps244. Theflaps244 are attached to acommon attachment position290 around the connectingmeans46. Eachflap244 has a contact surface292 with a coaptation area294 and theflap244 is moveable to put the coaptation area294 of the contact surface292 in contact with the leaflets of the native heart valve or the vessel wall. Theflaps244 are broadening towards the coaptation area294. Further, theflaps244 are overlapping and arranged as the leaves of a hibiscus flower so as to form a tight seal between them when extending to make contact with the heart valve or the vessel wall. Theflaps244 further have a strengthenedbase296 close to theattachment position290. The strengthenedbase296 will prevent theflap244 from turning over due to backflow in the heart valve or the vessel.
• In the fourth embodiment shown inFIGS. 7a-d, the valve means352 comprisesseveral flaps344 which are arranged side-by-side encircling the connectingmeans46. As indicated inFIG. 7cshowing a perspective view of the valve means352, eachflap344 comprises acontact surface392 with acoaptation area394. Theflaps344 are wedge-formed with the narrow end towards the connectingmeans46 and the broad end arranged to make contact with the native heart valve or the vessel wall. As indicated inFIG. 7ashowing a cross section of the valve means352 when inserted in a native heart valve or a vessel,adjacent flaps344 extend along each other and are arranged close together such that adjacent surfaces presentrespective coaptation areas392, which will be in close contact with each other to prevent leakage between theflaps344. InFIG. 7a, the valve means352 is depicted in the closed position in which it is arranged to make contact with the native heart valve or a vessel wall. When blood flows forward through the open valve means352 it will take the shape depicted inFIGS. 7band7d. Now the wedge-shapedflaps344 are pressed against the connectingmeans46 by the force of the blood stream and the valve means352 is open. This embodiment of the valve means352 would be especially effective in irregular shaped orifices, as for instance in severe calcified native heart valves.
• InFIGS. 7eand7f, attachment of theflaps344 to the connectingmeans46 is shown. Theflaps344 are attached to the connecting means46 in anattachment line390 along a longitudinal direction of the connectingmeans46. Theflap344 may be attached to the connecting means46 over the entire length of the flap344 (seeFIG. 7e) or over a part of the length of the flap344 (seeFIG. 7f). Thelonger attachment line390 makes enforcement strings unnecessary.
• As shown inFIGS. 7band7d, theflaps344 will collapse towards the connectingmeans46 when exposed to blood flow in the forward direction. The flap material is very thin to allow theflap344 to contract towards the connectingmeans46 when exposed to the blood flow.
• The flap or flaps of the valve means according to any embodiment are preferably made of biological tissue, which has been treated with glutaraldehyde or any tanning or fixation medium. The biological tissue may e.g. be tissue from pericardium or heart valve of an animal.
• The valve means may alternatively be made of polymers, such as polyurethane, polyvinyl, polyethylene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), or rayon. However, the flap or flaps may also be made of a shape memory material, such as Nitinol or shape memory polymers, whereby an ultrathin flap having a thickness of 3-4 μm may be formed.
• The valve means may be covered with active drugs. One such drug would be heparin, for prevention of clot formation in the blood circulation system of the patient. Another drug would be nitric oxide, which also prevents clot formation, and also a combination of heparin and nitric oxide is possible.
• Referring now toFIGS. 8-12, the use of anapparatus42 for controlling blood flow in a patient will be generally described. Theapparatus42 may be used for treating a regurgitating heart valve, as illustrated inFIGS. 8-9, or for controlling blood flow through an artery or a vein, as illustrated inFIGS. 10-12.
• FIGS. 8a-fillustrate the treatment of a regurgitatingmitral valve30. Themitral valve30 comprises aposterior leaflet35 and ananterior leaflet37. Theleaflets35,37 move for opening and closing themitral valve30.
• InFIG. 8a, a regurgitatingmitral valve30 is shown, where the posterior andanterior leaflets35,37 are not able to close the valve properly. Thevalve30 has aleak31 in a central position of thevalve30. InFIG. 8b, themitral valve30 with an implantedapparatus42 is shown. The valve means52 of theapparatus42 is placed in theleak31 such that acoaptation area94 between the valve means52 and theleaflets35,37 is created for closing theleak31. The valve means52 in its closed state makes contact with the leaflets in a short distance along thecontact surface92 such that a cylindrical surface constitutes thecoaptation area94 such that a tight seal is created. InFIG. 8c, another shape of the valve means52 is shown for treatment of theleak31. In this case, the valve means52 has a rectangular or an oval shape in its closed state, which may also effectively form acoaptation area94 for tightly sealing theleak31. InFIGS. 8dand8e, amitral valve30 having aleak31 positioned asymmetrically in thevalve30 is shown. Theapparatus42 is implanted such that the valve means52 is centrally positioned within theleak31 for forming acoaptation area94 in order to tightly seal theleak31. InFIG. 8f, a schematic cross-section of theheart1 is shown illustrating the placement of the valve means52 within themitral valve30. The valve means52 has a greater extension along the blood flow between theleft atrium26 and theleft ventricle17 than the nativemitral valve30. This implies that the valve means52 may effectively contact prolapsing leaflets that extend into theleft atrium26 and that the valve means52 may form atight coaptation area94 to many different shapes of leaks in themitral valve30. Such a great extension of the valve means52 along the blood flow also implies that the valve means52 effectively may contact leaflets restrained by shortened chordae tendinae11 inside theleft ventricle17.
• FIGS. 9a-cillustrate the treatment of a regurgitatingtricuspid valve8. Thetricuspid valve8 comprises a medial leaflet9a, a posterior leaflet9band an anterior leaflet9c. The leaflets9a,9b,9cmove for opening and closing thetricuspid valve8.
• InFIG. 9a, a regurgitatingtricuspid valve8 is shown, where the leaflets9a,9b,9care not able to close the valve properly. Thevalve8 has aleak19 in a central position of thevalve8. InFIG. 9b, thetricuspid valve8 with an implantedapparatus42 is shown. The valve means52 of theapparatus42 is placed in theleak19 such that acoaptation area94 between the valve means52 and the leaflets9a,9b,9cis created for closing theleak19. The valve means52 in its closed state makes contact with the leaflets in a short distance along thecontact surface92 such that a cylindrical surface constitutes thecoaptation area94 such that a tight seal is created. InFIG. 9c, a schematic cross-section of theheart1 is shown illustrating the placement of the valve means52 within thetricuspid valve8. The valve means52 has a greater extension along the blood flow between theright atrium6 and theright ventricle15 than the nativetricuspid valve8. This implies that the valve means52 may effectively contact prolapsing leaflets that extend into theright atrium6 and that the valve means52 may form atight coaptation area94 to many different shapes of leaks in thetricuspid valve8. Such a great extension of the valve means52 along the blood flow also implies that the valve means52 effectively may contact leaflets restrained by shortenedchordae tendinae10 inside theright ventricle15.
• FIGS. 10a-cillustrate use of theapparatus42 for controlling blood flow through the aorta, which may be used for treatment of a regurgitatingaortic valve32. Theapparatus42 may replace the function of theaortic valve32.
• As shown inFIG. 10a, the anchoring means54 of theapparatus42 may be placed in theaorta34 for fixing the position of theapparatus42. The anchoring means54 comprises astent55, which is expanded in contact with theaorta34 for fixing the position of theapparatus42. The anchoring means54 is preferably arranged on the “outflow” side of the valve means52 such that the valve means52 may be arranged close to the position of theaortic valve32. The valve means52 is placed upstream to a position wherecoronary arteries39 branches off from theaorta34. Thus, the valve means52 may effectively control blood flow from theleft ventricle17 to all parts of the body. The valve means52 is arranged to make contact with the walls of theaorta34 in acoaptation area94 for preventing blood flow past the valve means52. The valve means52 releases the contact and opens when exposed to blood flow from theleft ventricle17. InFIG. 10b, a specific embodiment of the valve means52 is illustrated. The valve means52 comprisesrecesses97 corresponding to the openings of thecoronary arteries39 to the aorta. Thus, the valve means52 may be arranged at least partly overlapping the position in the aorta where thecoronary arteries39 branches off from the aorta. The valve means52 will prevent blood flow between theaorta34 and theleft ventricle17 when the valve means52 is closed, leaving thecoronary arteries39 open to theaorta34 in order to permit blood flow to the heart muscle. Instead of havingrecesses97 in theflap44, the valve means52 may be positioned with therim96 arranged just below the coronary artery opening in theaorta34. Thus, blood flow to the coronary arteries during diastole may occur undisturbed even when the valve means52 is in the closed position. As a matter of fact, the valve means52 may be positioned partly inside theleft ventricle17 such that theflap44 is leaning on theanterior leaflet37 of themitral valve30. As shown inFIG. 10c, afurther stent41 may be arranged in theaorta34 at the position of theaortic valve32. Thisstent41 may press the malfunctioningaortic valve32 and any calcification thereof against the wall of theaorta34, such that the blood flow control of the valve means52 of theapparatus42 is not disturbed by the nativeaortic valve32 if this is calcified. Thisstent41 may be a covered or at least partially coveredstent41. The coveredstent41 may be positioned partly inside theleft ventricle17 in order to be arranged upstream of thecoronary arteries39. The coveredstent41 thereby provides a channel from inside theleft ventricle17 into theaorta34.
• FIGS. 11a-dillustrate use of theapparatus42 for controlling blood flow through thepulmonary artery22, which may be used for treatment of a regurgitatingpulmonary valve20. Theapparatus42 may replace the function of thepulmonary valve20.
• As shown inFIG. 11a, the anchoring means54 of theapparatus42 may be placed in thepulmonary artery22 for fixing the position of theapparatus42. The anchoring means54 comprises astent55, which is expanded in contact with thepulmonary artery22 for fixing the position of theapparatus42. The anchoring means54 is arranged on the “outflow” side of the valve means52 such that the valve means52 may be arranged close to the position of the pulmonary valve. The valve means52 is placed to effectively control blood flow from theright ventricle15 to the lungs. The valve means52 is arranged to make contact with the walls of thepulmonary artery22 in acoaptation area94 for preventing blood flow past the valve means52. The valve means52 releases the contact and opens when exposed to blood flow from theright ventricle15. InFIG. 11b, another positioning of the anchoring means54 is illustrated. The anchoring means54 is placed in the mainleft branch24 of thepulmonary artery22. The connecting means46 may in this embodiment have a preprogrammed shape to adapt to the curve of the artery between the position of the valve means52 and the anchoring means54. As shown inFIG. 11c, the anchoring means54 may alternatively be arranged on the “inflow” side of the valve means52. The anchoring means54 fixes the position of theapparatus42 in a position of thepulmonary artery22 close to theright ventricle15. The valve means52 may then be placed in a position in thepulmonary artery22 upstream of a position where thepulmonary artery22 branches into the left and right pulmonary arteries. Thus, the valve means52 is still placed to effectively control the blood flow from the right ventricle to the lungs. As shown inFIG. 11d, afurther stent43 may be arranged in thepulmonary artery22 at the position of thepulmonary valve20. Thisstent43 may press the malfunctioning pulmonary valve and any calcification thereof against the wall of thepulmonary artery22, such that the blood flow control of the valve means52 of theapparatus42 is not disturbed by the nativepulmonary valve20. As for thestent41, thestent43 may also be a covered or at least partially coveredstent43.
• InFIG. 12, there is shown a bloodflow controlling apparatus42 being positioned in thesuperior vena cava2 and another bloodflow controlling apparatus42 being positioned in theinferior vena cava4. The valve means52 is arranged to make and release contact with the wall of thesuperior vena cava2 and theinferior vena cava4, respectively, for opening and closing blood flow through the vessel. A valve means52 in thesuperior vena cava2 orinferior vena cava4 may be useful in cases of congenital defects where it is impossible to place a valve means52 in thepulmonary artery22. Then, the valve means52 may instead be placed upstream in the blood circulation system, such as shown inFIG. 12.
• Referring now toFIGS. 13a-k, the positioning and anchoring of different embodiments of the apparatus for placing the valve means in the mitral or tricuspid valve will be described. The valve means is arranged in the mitral or tricuspid valve for improving the valve function as described above with reference toFIGS. 8-9. The apparatus may be anchored in a number of different ways, as is shown inFIGS. 13a-k. Depending on how the apparatus is anchored, the anchoring means is designed in different ways. It will be appreciated by those skilled in the art, that the apparatus may be designed in many other alternative ways for appropriately placing the valve means in a heart valve or within a blood vessel.
• InFIG. 13a, theapparatus42 is arranged such that the valve means52 is placed in thetricuspid valve8. The position of theapparatus42 is fixed in the body by the anchoring means54 being placed in thesuperior vena cava2 for engaging the wall of the vessel. An embodiment of the anchoring means54 as shown inFIG. 3bis used. The connecting means146 extends through theright atrium6 between thesuperior vena cava2 and thetricuspid valve8 for connecting the valve means52 to the anchoring means54. InFIG. 13b, theapparatus42 is arranged such that the valve means52 is placed in themitral valve8. Now, an anchoring means54 as shown inFIG. 3cis used for engaging the wall of thesuperior vena cava2. The connecting means246 extends from thesuperior vena cava2, through theright atrium6, penetrating theinteratrial septum14 and through theleft atrium26 to the valve means52 placed in themitral valve30. The connecting means46 may have a preprogrammed shape adapted to its extension between thesuperior vena cava2 and themitral valve30. Alternatively, the connectingmeans46 may be flexible for allowing it to be appropriately shaped and thereafter locked in the appropriate shape.
• InFIG. 13c, anapparatus42 as shown inFIG. 3dis used for treating amitral valve30. The anchoring means154 is expanded to contact the inner wall of theleft atrium26 for fixing the position of theapparatus42, while the valve means52 is arranged in themitral valve30. InFIG. 13d, another way of using theapparatus42 shown inFIG. 3bis shown. The anchoring means54 is now arranged to make contact with a vessel wall in apulmonary vein28 and the connectingmeans46 is arranged extending through theleft atrium26 to the valve means52 which is arranged in themitral valve30.
• FIGS. 13e-iillustrate different embodiments of the anchoring means54 for use when the valve means52 is arranged in themitral valve30. It will be appreciated by those skilled in the art that these embodiments may be used instead for placing the valve means52 in thetricuspid valve8. InFIG. 13e, an apparatus as shown inFIG. 4bis used. The anchoring means354 is arranged to engage the chordae tendinae11 such that the chordae tendinae11 are captured within thehooks355 of the anchoring means354 for fixing the position of theapparatus42. InFIG. 13f, an apparatus as shown inFIG. 4dis used. The anchoring means554 is arranged to engage the mitral valve annulus. The anchoring means554 is shown penetrating the valve annulus with disk-shapedelements555 engaging opposite sides of the valve annulus for fixing the position of theapparatus42. Further, another disk-shapedelement555 is arranged in contact with a ventricular side of the valve annulus for stabilizing theapparatus42 within theleft ventricle17. InFIG. 13g, anapparatus42 as shown inFIG. 4cis used. The anchoring means454 hasclips455 which are arranged engaging thepapillary muscles13 for fixing the position of theapparatus42. InFIGS. 13hand13i, anapparatus42 as outlined inFIG. 4ais used. The anchoring means254 has a disk-shapedelement255 which is arranged in contact with a tissue wall. The valve means52 and the anchoring means254 are arranged on opposite sides of the tissue wall and the connectingmeans46 penetrates the tissue wall. The anchoring means254 in contact with the tissue wall therefore fixes the position of theapparatus42. However, inFIGS. 13hand13i, the anchoring means254 comprises another disk-shapedelement255 such that the disk-shapedelements255 engage opposite sides of the tissue wall for securely fixing the position of theapparatus42. InFIG. 13h, the anchoring means254 is arranged to engage theinterventricular septum16 and inFIG. 13i, the anchoring means254 is arranged to engage the leftventricle muscle wall18.
• FIGS. 13jand13killustrate anapparatus42 being used for simultaneously treating themitral valve30 and thetricuspid valve8. Theapparatus42 comprises two valve means52 being positioned in the respective native valves. Theapparatus42 comprises a connectingmeans46 connecting the two valve means52. The connecting means46 is arranged extending between the valves through the interventricular septum16 (as shown inFIG. 13j) or the interatrial septum14 (as shown inFIG. 13k), respectively. Further, theapparatus42 comprises anchoring means254 having disk-shapedelements255 which are arranged on opposite sides of theinterventricular septum16 orinteratrial septum14, respectively, in order to engage tissue and fix the position of theapparatus42.
• Referring now toFIGS. 14a-h, adelivery system500 for inserting theapparatus42 into a patient will be described. As shown inFIG. 14a, thedelivery system500 comprises aguide wire508, which is first introduced into the patient extending to the position where theapparatus42 is to be placed. Theguide wire508 thereafter provides a guiding path to the desired position within the patient. Thedelivery system500 further comprises adelivery catheter502, which is the outermost part of thedelivery system500 within the vascular system of the patient. For the sake of clarity, thedelivery catheter502 is not shown in the following figures of thedelivery system500. Theapparatus42 is guided to the position inside thedelivery catheter502. Thedelivery system500 further comprises a restrainingcatheter504. Thiscatheter504 keeps theapparatus42 in a compressed state during delivery. Thedelivery system500 further comprises aninner tube506 which is arranged to slide on the guide wire to the desired position and push theapparatus42 in front of it.
• Referring toFIGS. 14b-d, deployment of anapparatus42 will be indicated. InFIG. 14b, theentire apparatus42 is inside the restrainingcatheter504. The valve means52 is arranged distal to the anchoring means54 in the restrainingcatheter504, that is the valve means52 is introduced into the patient in front of the anchoring means54. The restrainingcatheter504 is retracted to release the restrain on the valve means52, as shown inFIG. 14c. Thus, the valve means52 is expanded, while the anchoring means54 is kept in a compressed state. The restrainingcatheter504 is then further retracted, releasing the anchoring means54, as shown inFIG. 14d. Now, theentire apparatus42 is deployed.
• Referring toFIGS. 14e-g, another deployment of anapparatus42 will be described. InFIG. 14e, theentire apparatus42 is inside the restrainingcatheter504. Now, the valve means54 is arranged distal to the anchoring means52 in the restrainingcatheter504. Again, the restrainingcatheter504 is retracted to release the restrain on the anchoring means54, as shown inFIG. 14f. Thus, the anchoring means54 is expanded for fixing the position of theapparatus42, while the valve means52 is kept in a compressed state. The restrainingcatheter504 is then further retracted, releasing the valve means52, as shown inFIG. 14g. Now, theentire apparatus42 is deployed.
• InFIG. 14h, thedelivery system500 is shown in connection to anapparatus42 having a connectingmeans46 with alock137 for providing a possibility to detach the valve means52 from the anchoring means54. The detachment mechanism can be utilized for storage purposes. When the valve means52 are made of glutaraldehyde-treated biological tissue, the valve means52 can be stored in a liquid fluid while the rest of theapparatus42 anddelivery system500 may be stored under dry conditions. When making ready for use, the valve means52 that has been stored in liquid may be rinsed and thereafter connected to the anchoring means54 by attaching themale portion138 of thelock137 to thefemale portion140 of thelock137. Thereafter the valve means52 may be folded and retracted or pushed inside the restrainingcatheter504 to make theentire apparatus42 ready for insertion into a patient.
• Referring now toFIGS. 15-20, methods for inserting anapparatus42 into a patient will be described.
• Referring first toFIGS. 15a-e, a method for inserting anapparatus42 for treatment of thetricuspid valve8 will be described. InFIG. 15a, a body of a patient is shown, indicating theheart1 and access to theheart1 via the vascular system. A puncture is made in the groin of the patient for accessing thefemoral vein5, which leads to theinferior vena cava4 and further to theright atrium6 of theheart1. Anintroducer sheath501 of thedelivery system500 is applied in the puncture for providing an access tube into thefemoral vein5. Theguide wire508 of thedelivery system500 is lead into theright atrium6 for providing guidance of theapparatus42 to the desired position. InFIG. 15b, another access route to theright atrium6 is indicated. A puncture is made in the neck of the patient for accessing the internaljugular vein7 of the patient. Theguide wire508 is lead through the internaljugular vein7 to thesuperior vena cava2 and into theright atrium6. Theguide wire508 is further introduced extending through thetricuspid valve8 into theright ventricle15. As shown inFIG. 15c, thedelivery catheter502 is now introduced extending to the orifice of thetricuspid valve8. For the sake of clarity, thedelivery catheter502 will not be shown in the followingFIGS. 15d-e. Now, the restrainingcatheter504 and theapparatus42 is introduced over theguide wire508 to thetricuspid valve8. As shown inFIG. 15d, the restrainingcatheter504 is retracted so far that the valve means52 is released inside the orifice of thetricuspid valve8. Theentire delivery system500 with theapparatus42 may still be moved in the axial direction to find the optimal position of the valve means52 in the orifice of thetricuspid valve8. During this positioning, the effect of the introduced valve means52 may be controlled simultaneously by means of ultrasound. The restraining means504 is thereafter withdrawn further and finally from the body, as shown inFIG. 15e. Hereby, the anchoring means54 is deployed inside thesuperior vena cava2 and theapparatus42 is completely deployed. Theapparatus42 has now been implanted for providing permanent treatment of thetricuspid valve8. Theinner tube506, thedelivery catheter502 and theguide wire508 may now also be withdrawn.
• Referring now toFIGS. 16a-d, a method for inserting anapparatus42 for treatment of themitral valve30 will be described. InFIG. 16a, an access route to theleft atrium26 is indicated. A puncture is made in the neck of the patient for accessing the internaljugular vein7 of the patient. Theguide wire508 is lead through the internaljugular vein7 to thesuperior vena cava2 and into theright atrium6. Theguide wire508 is further introduced through theinteratrial septum14 into theleft atrium26 and further through themitral valve30 into theleft ventricle17. If the patient has a persistent foramen ovale, theguide wire508 may instead be lead from theright atrium6 through the foramen ovale into theleft atrium26. As shown inFIG. 16b, thedelivery catheter502 is thereafter introduced over theguide wire508 extending to the orifice of themitral valve30. Again, thedelivery catheter502 will not be shown in the followingFIGS. 16c-d. The restrainingcatheter504 with theapparatus42 is now introduced over theguide wire508 extending to themitral valve30. Thereafter, the restrainingcatheter504 is retracted, as shown inFIG. 16c, so that the valve means52 is released inside the orifice of themitral valve30. Again, theentire delivery system500 with theapparatus42 may still be moved in the axial direction to find the optimal position of the valve means52 in the orifice of themitral valve30. The restrainingcatheter504 is thereafter withdrawn to release the anchoring means54 and finally withdrawn from the patient. As shown inFIG. 16d, the anchoring means54 has been deployed inside thesuperior vena cava2 and theapparatus42 is completely deployed.
• Referring now toFIGS. 17a-d, a method for inserting anapparatus42 for treatment of thepulmonary valve20 will be described. InFIG. 17a, an access route to thepulmonary artery22 is indicated. A puncture is made in the neck of the patient for accessing the internaljugular vein7 of the patient. Theguide wire508 is lead through the internaljugular vein7 to thesuperior vena cava2 and into theright atrium6. Theguide wire508 is further introduced through thetricuspid valve8, theright ventricle15 and into thepulmonary artery22. The restrainingcatheter504 is introduced over theguide wire508 and inside thedelivery catheter502 to extend into thepulmonary artery22, as shown inFIG. 17b. The restrainingcatheter504 is retracted, as shown inFIG. 17c, so that the anchoring means54 is released inside thepulmonary artery22 for fixing the position of theapparatus42. The restrainingcatheter504 is further retracted and withdrawn from the patient. As shown inFIG. 17d, the valve means52 is deployed inside thepulmonary artery22 at the position of thepulmonary valve20 and theapparatus42 is completely deployed. The same method may be used in case the anchoring means54 is arranged on an “inflow” side of the valve means52, as shown inFIG. 11c, or when astent43 is arranged in the pulmonary valve position, as shown inFIG. 11d. In the latter case, thestent43 is first implanted at the position of thepulmonary valve20. Thereafter, theapparatus42 is inserted.
• Referring now toFIGS. 18a-d, a method for inserting anapparatus42 for treatment of theaortic valve32 will be described. InFIG. 18a, an access route to theaortic valve32 is indicated. A puncture is made in the neck of the patient for accessing the internaljugular vein7 of the patient. Theguide wire508 is lead through the internaljugular vein7 to thesuperior vena cava2 and into theright atrium6. Theguide wire508 is further introduced through theinteratrial septum14 into theleft atrium26, further through themitral valve30 into theleft ventricle17, and through theaortic valve32 into theaorta34. Alternatively, the route through a persistent foramen ovale might be chosen, as described above with reference to FIG.16a. The restrainingcatheter504 and theapparatus42 is introduced inside the delivery catheter (not shown) such that the restrainingcatheter504 extends into the ascendingaorta33, as shown inFIG. 18b. The valve means52 is located adjacent to theaortic valve32 such that therim96 of the valve means52 is located just below the orifices of thecoronary arteries39. Alternatively, the apparatus depicted inFIG. 10bis used, wherein the valve means52 comprisesrecesses97 to fit the orifices of thecoronary arteries39. The restrainingcatheter504 is retracted, as shown inFIG. 18c, such that the anchoring means54 is released inside the ascendingaorta33 for fixing the position of theapparatus42. The restrainingcatheter504 is further retracted and finally withdrawn from the patient. As shown inFIG. 18d, the valve means52 is deployed inside the aortic ostium and theapparatus42 is completely deployed.
• Referring now toFIGS. 19a-d, another method for inserting anapparatus42 for treatment of theaortic valve32 will be described. InFIG. 19a, an access route to theaortic valve32 is indicated. A puncture is made in the groin of the patient to access afemoral artery38. Aguide wire508 is passed through thefemoral artery38, the descendingaorta36 to the ascendingaorta33 and into theleft ventricle17. Alternatively, other arteries can be used such as thesubclavian artery29. Aguide wire508 is introduced through the arteries to the ascendingaorta33, through theaortic valve32 and into theleft ventricle17. InFIG. 19b, theguide wire508 has been introduced through thesubclavian artery29 into theaorta34. The restrainingcatheter504 and theapparatus42 are introduced inside the delivery catheter (not shown) such that the restrainingcatheter504 extends into the ascendingaorta33. The valve means52 is located adjacent to theaortic valve32 with therim96 of the valve means52 being located below the orifices of thecoronary arteries39. As shown inFIG. 19c, the restrainingcatheter504 is retracted such that the valve means52 is released inside theaortic valve32. Again, theentire delivery system500 with theapparatus42 may still be moved in the axial direction to find the optimal position of the valve means52 at theaortic valve32. The restrainingcatheter504 is thereafter withdrawn further and finally from the patient. As shown inFIG. 19d, the anchoring means54 has been deployed inside the ascendingaorta33 and theapparatus42 is completely deployed.
• Referring now toFIGS. 20a-e, methods for introducing anapparatus42 into theinferior vena cava4 and thesuperior vena cava2, respectively, will be described. InFIG. 20a, an access route to theinferior vena cava4 is indicated. A puncture is made in the neck of the patient to access the internaljugular vein7. Aguide wire508 is passed through the internaljugular vein7 into thesuperior vena cava2 and theright atrium6 and further into theinferior vena cava4. The restrainingcatheter504 and theapparatus42 are introduced inside the delivery catheter (not shown) such that the restrainingcatheter504 extends into theinferior vena cava4. As shown inFIG. 20b, the restrainingcatheter504 is retracted such that the anchoring means54 is released inside theinferior vena cava4 for fixing the position of theapparatus42. The restrainingcatheter504 is thereafter withdrawn further and finally from the patient. As shown inFIG. 20c, the valve means52 has been deployed inside theinferior vena cava4 and theapparatus42 is completely deployed.
• The same access route may be used for placing anapparatus42 in thesuperior vena cava2. The restrainingcatheter504 and theapparatus42 are introduced into thesuperior vena cava2. The restrainingcatheter504 is retracted such that the valve means54 is released inside thesuperior vena cava2, as shown inFIG. 20d. The restrainingcatheter504 is withdrawn further and finally from the patient. As shown inFIG. 20e, the anchoring means54 is deployed inside thesuperior vena cava2 and theapparatus42 is completely deployed. If the groin access to the femoral vein is used, anapparatus42 would first be deployed in thesuperior vena cava2 and anapparatus42 would secondly be deployed in theinferior vena cava4 using an identical method.
• It should be emphasized that the preferred embodiments described herein is in no way limiting and that many alternative embodiments are possible within the scope of protection defined by the appended claims. For example, the different embodiments of the valve means and the anchoring means may be combined in any manner. Further, it would be apparent to a person skilled in the art, that other veins or arteries may be chosen in order to obtain access to the large vessels around the heart and to the different chambers of the heart.

Claims (20)

1. A prosthesis for improving blood flow through a native heart valve within a heart comprising:

an anchoring framework configured to engage tissue associated with the heart and thereby anchor the prosthesis; and

a valve member coupled to the anchoring framework and extending from the anchoring framework so as to be interposed between leaflets of the native heart valve when the anchoring framework is engaged with the tissue;

wherein the valve member has an expanded configuration for contacting at least one leaflet of the native heart valve during a first direction of blood flow and the valve member has a contracted configuration for releasing contact with at least one leaflet of the native heart valve during a second direction of blood flow.

2. The prosthesis ofclaim 1, wherein the anchoring framework comprises a tissue engagement structure configured to engage ventricular tissue in the heart.

3. The prosthesis ofclaim 2, wherein the anchoring framework further comprises a connecting member for coupling the valve member to the tissue engagement structure.

4. The prosthesis ofclaim 1, wherein the anchoring framework is a stent configured for deployment in a body lumen.

5. The prosthesis ofclaim 1, wherein the valve member is expandable in a direction transverse to the flow of blood for preventing regurgitation through the native heart valve.

6. The prosthesis ofclaim 1, wherein the valve member comprises an umbrella-shaped flexible flap.

7. The prosthesis ofclaim 6, wherein the anchoring framework includes an elongated rod extending through a center region of the umbrella-shaped flap.

8. The prosthesis ofclaim 7, further comprising a plurality of flexible connecting members extending from a peripheral edge of the umbrella-shaped flap and the anchoring framework.

9. An apparatus for restoring function to a mitral valve in a human heart, comprising:

a flow control member; and

an anchor having a first end and a second end, the first end of the anchor being connected to the flow control member, the second end of the anchor having a tissue engagement structure, the anchor having a length such that the flow control member is positioned at least partially within the mitral valve when the tissue engagement structure is engaged with the tissue;

wherein the flow control member is movable between an expanded state to contact at least one leaflet of the mitral valve and thereby substantially prevent blood flow past the mitral valve and a reduced state to thereby allow blood flow past the mitral valve.

10. The apparatus ofclaim 9, wherein the anchor is elongated between the first and the second ends.

11. The apparatus ofclaim 10, wherein the flow control member is a flexible umbrella-shaped flap.

12. The apparatus ofclaim 11, further comprising a plurality of connecting threads extending from a circumference of the umbrella-shaped flap to the anchor.

13. The apparatus ofclaim 9, wherein the tissue engagement structure includes a framework of struts engageable with an interior surface of the heart.

14. The apparatus ofclaim 13, wherein the tissue engagement structure comprises a plurality of hooks.

15. A method for restoring function to a heart valve in a human heart, comprising:

introducing a prosthesis into an interior of the heart;

securing one end of the prosthesis to tissue within the heart;

positioning an opposite end of the prosthesis between opposing leaflets of the heart valve;

expanding the prosthesis so as to place the prosthesis into contact with at least one leaflet of the heart valve and thereby substantially prevent blood flow through the heart valve in a first direction; and

contracting the prosthesis so as to substantially allow blood flow through the heart valve in a second direction.

16. The method ofclaim 15, wherein the securing of one end of the prosthesis in the heart includes extending the one end of the prosthesis at least partially through heart tissue in a left ventricle.

17. The method ofclaim 15, wherein expanding the prosthesis to contact at least one leaflet of the heart valve includes coapting at least one leaflet of the heart valve with the prosthesis.

18. The method ofclaim 15, wherein expanding the prosthesis to contact at least one leaflet of the heart valve includes expanding an umbrella-like flexible flap disposed at one end of the prosthesis.

19. The method ofclaim 18, further comprising securing a periphery of the flexible flap to the prosthesis with a plurality of flexible connecting members extending between the periphery of the flexible flap and the prosthesis.

20. The method ofclaim 18, wherein the contracting the prosthesis to substantially allow blood flow includes allowing the umbrella-like flexible flap to collapse.

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