US20220168098A1 - Heart anchor device - Google Patents

Abstract

A medical implant including an anchor portion including a plurality of arms adapted to engage an internal tissue wall of a body from two opposite faces, wherein the anchor portion is configured such that at least one of the arms does not have an entirely overlapping arm on the other side of the wall and an opening portion adapted to define an opening for blood flow through the internal tissue wall, when the anchor portion engages the wall.

Description

RELATED APPLICATIONS
• The present application claims the benefit under 35 USC 119(e) of U.S. Provisional applications 60/862,496, filed Oct. 23, 2006, 60/777,315, filed Feb. 28, 2006 and 60/761,192, filed Jan. 23,2006, the disclosures of all of which are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
• The present invention relates to heart implants for example to implants for the heart which can be delivered in a minimally invasive procedure.
BACKGROUND OF THE INVENTION
• The heart operates as a pump which causes blood to flow throughout the body. In various cases, patients suffer from blockages and/or pressure elevation and it is required to keep a passage open for blood flow. In other patients, an undesired flow path opens and it is required to close the flow path. In such patients, stents, valves or seals are implanted to achieve a required blood flow pattern.
• An article titled “Creation with a stent of an unrestrictive lasting atrial communication”, by Marc Gewillig et a., Cardiol Young 2002; 12(4):404-7, the disclosure of which is incorporated herein by reference, describes use of a stent to create an unrestrictive and atrial communication. An article titled “Modified technique of stent fenestration of the atrial septum”, Stümper et al., 89 (10): 1227, Heart 2003, the disclosure of which is incorporated herein by reference, describes placing a stent across a fenestration and expanding the stent by a balloon.
• Various closure devices are known in the art.
• PCT publication WO 2005/027752, filed Sep. 13, 2004, the disclosure of which is incorporated herein by reference, describes a closure device formed of a pair of anchor members and a center flexible joint, which press on the septum and hold it closed.
• US patent publication 2006/0122647 to Callaghan et al., published Jun. 8, 2006, describes an occlusion device formed of a polymer tube that includes distal and proximal ends for securing to opposite ends of the septum.
• US patent publication 2007/0010852, to Blaeser et al., published Jan. 11, 2007, the disclosure of which is incorporated herein by reference, describes a device for sealing a patent foramen ovale (PFO) in the heart. The device includes a right atrial member including a plurality of arms and a cover attached to the arms, and a left atrial anchor including a plurality of arms.
• There are also various valves known in the art.
• PCT publication WO 2005/074367, published Aug. 18, 2005, the disclosure of which is incorporated herein by reference, describes a plurality of valves and methods of anchoring the valves in the heart. One anchoring method described is use of support arms opposite each other on both sides of a wall through which the valve passes.
• US patent publication 2006/0167541 to Lattouf, published Jul. 27, 2006, disclosure of which is incorporated herein by reference, describes a valve formed of a tube with hooks on both ends for anchoring in the heart and a leaflet valve placed in the tube.
• US patent publication 2004/0162514 to Alferness, the disclosure of which is incorporated herein by reference, describes a pop-off valve for placement in the heart between the left and right atriums. The valve includes spikes, referred to as anchor guides, which pierce a wall of the heart and thus keep the device in place. Such piercing is not always desirable as it may damage heart tissue.
• US patent publication 2006/0116710 to Corcoran et ale, the disclosure of which is incorporated herein by reference, describes an occlusion device having a relatively low profile against the occluded tissue.
SUMMARY OF THE INVENTION
• An aspect of some embodiments of the present invention relates to a medical implant adapted to define a passage in a tissue wall and to be anchored to the wall by a plurality of arms on both sides of the wall, at least some of the arms not having a matching overlapping arm on the other side of the wall.
• The arms optionally extend radially from the defined passage.
• In some embodiments of the invention, at least some of the arms do not have a corresponding arm on the other side of the wall, even not a corresponding arm which only partially matches the area of the arm. Alternatively or additionally, one or more of the arms have a corresponding arm on the other side of the wall whose area only partially matches the arm. In this alternative, one or more of the arms having a corresponding arm on the other side of the wall optionally have less than 50% of their length and/or area, matching to an arm on the other side of the wall.
• In one embodiment, all the arms do not meet an matching arm on the other side of the wall. By having the arms not press against each other on opposite sides of the wall, the pressure applied by the arms may be more evenly distributed, avoiding forming high pressure stress points on the tissue, which may result in deterioration of tissue at the stressed point and/or may damage the arms themselves.
• An aspect of some embodiments of the present invention relates to an anchor device adapted to be implanted across a wall of a body organ such as the heart. The anchor device is adapted to define an opening for blood flow with minimal contact of the blood in the opening with the implant. The length of the opening, measured in the perpendicular axis to the orifice plane, in which blood passing through the opening comes in contact with the implant is less than 3 millimeters or two millimeters. In some embodiments of the invention, the length of the opening is less than a millimeter or even less than half a millimeter. Optionally, the length of the opening is substantially equal to the thickness of the wall around the opening. In some embodiments of the invention, the anchor device defines the opening together with the wall tissue, such that the perimeter of the opening is mostly tissue and only less than 20%, less than 15% or even less than 10% or 7% of the perimeter is covered by the anchor device. Minimizing the length of a blood passage through the opening defined by the device, may improve washout and/or reduce residence time of the blood in the opening, which may result in avoiding tissue growth and/or blood clotting that will obstruct the opening.
• An aspect of some embodiments of the present invention relates to an anchor device adapted to define a passage through a wall of a body organ such as the heart, and to be implanted in the wall in a substantially flat configuration, in which the anchor device has a low profile minimal protrusion out of tissue wall. The anchor device is optionally adapted to have a thickness after implantation substantially equal to the thickness of the wall before implantation, for example up to 1 millimeter thicker than the wall or even not more than half a millimeter thicker.
• Optionally, in a deployed state of the anchor device its thickness is less than 3 millimeters, less than 2 millimeters or even less than 1 millimeter. In some embodiments of the invention, the thin dimension of the anchor device is perpendicular to the orifice axis and parallel the orifice plane. In some embodiments of the invention, the thickness of the anchor device when implanted on the wall is less than 5%, less than 2% or even less than 1% of the maximum end to end extent of the anchor device in the flat configuration. One potential advantage of using a flat device is that it may allow the device to be absorbed in the wall tissue.
• The term low profile refers herein to devices having a thin dimension that does not protrude substantially above a wall on which it is implanted. It is noted, however, that due to irregularity of the wall, the anchor device may not conform entirely to the surface of the wall, possibly diverging from the wall over 20% or even 40% of the area of the anchor device. In some embodiments of the invention, the anchor device is included in a flat plane regardless of the form of the wall. Alternatively, the anchor device may have a thin curved shape.
• It is a feature of some embodiments of the invention that the anchor device may serve as a base on which various units may be mounted. These units, which are not necessary for connecting the anchor device to the wall and holding the device in place, are not necessarily included in the low profile of the anchor device.
• In some embodiments of the invention, the anchor device is adapted in its flat configuration to hold an orifice in the body wall open, although the orifice is possibly blocked by a valve or closure sheet mounted on the anchor device. For example, the anchor device may hold the orifice open by applying a force in a radial direction, while carrying a closure unit which blocks the orifice in an axial direction. The anchor device optionally holds the orifice open by having some of the parts of the device on one side of the wall and some parts of the device on another side of the wall and the parts on the opposite sides of the wall being connected through the orifice.
• In some embodiments of the invention, the anchoring device is adapted for implantation in membranous tissue. Alternatively or additionally, the anchoring device is adapted for implantation in muscle tissue.
• The anchoring device optionally defines a central orifice which remains clear from portions of the anchoring device and/or elements mounted thereon, along the length of the anchor device. Optionally, in its deployed configuration, the device includes a plurality of petal shaped elements (referred to herein as petals) extending radially from the central orifice, some of which petals are adapted to be located on one side of the wall and others on the other side of the wall.
• In some embodiments of the invention, the anchoring device is formed using a minimal number of pieces (e.g., less than 5), requiring a minimal number of welds or other attachments. Optionally, the device is formed basically of a single elongate piece, e.g., a single wire. In an exemplary embodiment of the invention, the device is produced from a sheet by removing excess material, using a suitable cutting method (e.g., laser, water jet, chemical etching).
• The anchoring device optionally does not include sharp points, such as pins or spikes, adapted to penetrate the tissue in order to fasten to the wall. In some embodiments of the invention, the anchoring is performed without penetrating the tissue. Alternatively, spikes may be used to add to the strength of the bonding to the wall.
• An aspect of some embodiments of the present invention relates to an anchor device adapted to self expand from a folded state in which the anchor device has a first cross-section area to a deployed state in which the anchor device defines an orifice having a second cross-section area substantially larger than the first cross-section area. Optionally, the anchor device is adapted to be implanted in an orifice in a wall of a body organ such as the heart.
• In some embodiments of the invention, the second cross section area is at least 50%, 100% or even by at least 150% greater than the first area. Alternatively or additionally, the diameter of the orifice defined by the anchor device in the deployed state is at least 20%, 30%, 50% or even at least 100% larger than the diameter in the folded state.
• In an exemplary embodiment of the invention, the anchor device is delivered in a delivery tool (e.g., a delivery sheath) having a diameter of less than 12 French or even less than 10 French (e.g., 8 French). The anchor device is optionally inserted into a previously dilated orifice with a diameter close to that of the delivery tool, which orifice is expanded by the anchor device to a diameter of at least 12 French, or even to a diameter of 15 French, for example about 18 French. In an exemplary embodiment of the invention, the anchor device is adapted to expand from a diameter of about 4 millimeters when inserted into a deployed state in which it defines an orifice having a diameter of at least 6 millimeters.
• In some embodiments of the invention, the dimensions of the orifice defined by the anchor device depend on the thickness and structure of the wall tissue.
• The anchoring device may be adapted to keep the orifice open or may carry a flap or other unit which is adapted to close the orifice some times or all the time or may carry a tube, cardiac assist device, a sensor or any other device.
• An aspect of some embodiments of the invention relates to a method of perforating an orifice in the septum. The method includes puncturing a small orifice in the septum, inserting an expandable unit into the punctured orifice and expanding the expandable unit to increase the size of the orifice. In some embodiments of the invention, the expandable unit comprises a balloon. Alternatively or additionally, the expandable unit comprises an implant which is implanted in the orifice and remains in the orifice for at least a day, a week or even a month after expanding the orifice.
• In some embodiments of the invention, the punctured orifice before expansion has a diameter of less than 3 millimeters, less than 2 millimeters or even not more than 1 millimeter.
• Optionally, the anchor device expands most of its expansion upon being released from a delivery tool on which it is brought to the orifice. Alternatively or additionally, the anchor device is adapted to continue its expansion minutes, hours or even days after it is implanted in the hole.
• An aspect of some embodiments of the present invention relates to a valve adapted for implantation in a human body in a minimally invasive procedure, formed of an anchoring unit adapted to define a blood passage, and a single flap which covers the entire blood passage. Using a single flap for the valve may make the valve simpler and/or more robust. In some embodiments of the invention, using a single flap directs the blood flow passing through the orifice in an angle relative to the orifice, possibly even perpendicular to the flap, and thus generates in some of these embodiments, a washout flow in a direction different from the primary flow. In addition, the use of a single large flap may allow easier viewing of the flap operation using medical imaging modalities, such as fluoroscopy and ultrasound imaging.
• The blood passage may be defined by the anchoring unit itself, such that along the blood passage the blood comes in contact substantially only with the anchoring unit, or by the anchoring unit together with human tissue, such that blood passing through the blood passage contacts both human tissue and the anchoring device.
• In some embodiments of the invention, the flap has an area at least 20%, 40%, 70% or even at least 100% greater than the area of the blood passage, Using a flap substantially larger than the blood passage may provide a better closing of the blood passage and/or assure overlap and seal in a relatively flexible and compliant organ. In addition, the large flap may make it easier to open the flap and/or may add to the stability, predictability and/or accuracy of the valve's performance. In some embodiments of the invention, the flap has an area even 120% or 150% greater than the blood passage.
• Possibly, a flat sheet, for example having a disc like shape with an orifice larger than the blood passage (referred to herein as a skirt) radially surrounds the blood passage, parallel to the cross section of the orifice. In some embodiments of the invention, the flap is adapted to close against the skirt, such that the skirt optionally protects tissue underneath it from being hit by movements of the flap and/or prevents tissue growth toward the flap. Optionally, the skirt has a width of at least 1 millimeter or even at least two millimeters. In some embodiments of the invention, larger widths of the disc shape are used, for example with a width of at least 5 or even 9 millimeters. Using a large width is expected to prevent cell growth on the skirt. The skirt optionally has a thickness of at least 0.5 millimeters or even at least 0.8 millimeters, which thickness is expected to prevent tissue growth and wrapping on the skirt. Optionally, the distance from the outer edge of the blood passage to the inner edge of the skirt is at least 1 or even at least 2 millimeters, in order to prevent tissue growth in the blood passage.
• An aspect of some embodiments of the present invention relates to a valve adapted for implantation in a human body in which a flap of the valve has a hinge substantially remote from the passage covered by the flap. A single flap may cover the entire passage or a plurality of flaps may cooperate to cover the passage. A remote hinge allows for a safe location of the hinge, where it does not obstruct blood flow through the orifice. In addition, when the movement of the flap is based on the spring properties of an arm holding the flap, a long arm provides a low spring constant.
• In some embodiments of the invention, a maximal curvature point of the hinge of the flap is at least 1 millimeter, at least 3 millimeters or even at least 5 millimeters or 10 millimeters away from the passageway blocked by the flap. Optionally, the hinge of the flap is separated from the blocked passageway by at least 20%, 40% or even 60% of an end to end extent (referred to herein as the diameter even in non circular shapes) of the cross-section of the passageway.
• The hinge optionally extends over a long length of an arm carrying the flap. In such cases when a distance from the hinge is referred to herein, the distance relates to a distance to a maximal curvature point along the hinge. In some embodiments of the invention, the arm is produced with a single hinge. Alternatively, the arm carrying the flap has a plurality of weak points adapted to serve as hinges. In some embodiments of the invention, an integral pivot point of the arm is located in the hinge, optionally close to the maximal curvature point of the hinge. Alternatively to a U shaped hinge in an arm, other hinges may be used, such as a hinge formed of a rotating pin.
• An aspect of some embodiments of the present invention relates to a valve adapted for implantation in a human body in which a flap of the valve has a hinge around which it moves between an open and a closed state. The valve also includes a movement restrictor separate from the hinge, which restricts the movement of the flap.
• Optionally, the movement restrictor limits at least some movements of the flap allowed by its mounting at the hinge. In some embodiments of the invention, the movement restrictor prevents movements of the flap due to large pressures on the valve, above an allowed level. Alternatively or additionally, a movement restrictor connects the flap to a different point on the valve, in a manner which does not limit the movement of the flap at the hinge, but restricts movement of the flap if the mounting at the hinge breaks.
• In some embodiments of the invention, a wire, string or other stopper is positioned in the opening direction of the flap at a position which blocks or at least restricts the movement of the flap beyond the position. Alternatively or additionally, the wire, string and/or stopper is positioned in a manner which restricts the closing of the flap, forcing the flap to be in a partially open state. Further alternatively or additionally, a thin flexible element, such as a wire or string connects the flap to a stationary point, in a manner which prevents undesired movements of the flap. In some embodiments of the invention, the thin flexible element is connected along an arm of the flap, attached to the flap. In some embodiments of the invention, a spring is used instead of or in addition to the thin flexible element.
• An aspect of some embodiments of the present invention relates to a valve adapted for implantation in a human body including a flap held by an arm including a hinge. The arm of the flap is adapted to be spread out over the hinge of the arm to an angle of more than 150°, more than 165°, or even substantially 180°. In some embodiments of the invention, the arm is adapted to be spread out during delivery, before being put into operation.
• An aspect of some embodiments of the present invention relates to an orifice closing device adapted for use within a human body. The closing device is formed of an anchoring portion which defines an orifice and a closing portion which is adapted to seal the orifice upon deployment, without the aid of tissue growth on the closing device.
• In some embodiments of the invention, the anchoring portion is adapted to contact tissue surrounding the orifice in at least two, three or even at least five points. The relative positions of the points at which the anchoring portion is adapted to contact tissue are optionally predetermined before deployment. In some embodiments of the invention, the positions of the contact points are only partially predetermined, for example when the anchoring portion is elastic.
• The anchoring portion is optionally a single unit connected at one or more points to the closing portion. Alternatively, the anchoring portion comprises a plurality of separate anchors, which are separately connected to the closure device.
• The closing portion optionally covers a larger area than an orifice defined by the anchoring portion, in order to achieve a tight seal. Optionally, the area covered by the closing portion is at least 10%, 20% or even at least 40% greater than the maximal orifice defined by the anchoring portion.
• In some embodiments of the invention, the closing device is adapted for use in percutaneous procedures, optionally being deliverable through a catheter having a maximal diameter of less than 18 French or even less than 12 French.
• An aspect of some embodiments of the present invention relates to a method of treatment of humans in which an orifice is closed by percutaneously bringing a closure device to an orifice and implanting the closure device in the orifice in a manner which seals the orifice substantially immediately (e.g., less than a minute or even less than ten seconds) upon deployment. The term seal refers herein to a state in which no blood or very little blood (e.g., less than 10 milliliters prer minute) passes through the orifice.
• An aspect of some embodiments of the present invention relates to an orifice closing device for closing an orifice in a tissue wall of a human, which comprises an opening unit adapted to hold the orifice open and a cover unit adapted to at least partially cover the orifice.
• In some embodiments of the invention, the cover unit entirely covers the orifice and prevents flow of blood through the orifice. Alternatively or additionally, the cover unit comprises a mesh which covers the orifice but allows flow therethrough. Optionally, the mesh supports and/or serves as a scaffold for tissue growth. In some embodiments of the invention, the density of the mesh is selected to achieve a desired rate of tissue growth thereon. Further alternatively or additionally, the cover unit has one or more orifices defined therein.
• An aspect of some embodiments of the present invention relates to a method of closing an orifice in a body organ. The method includes implanting in the orifice a valve including a bio-degradable material which maintains the valve in an open position or in a state in which it may open and close. As the bio-degradable material dissolves or after it dissolves, the valve changes to a permanently closed state.
• In some embodiments of the invention, the bio-degradable material (e.g., Poly Ethylene Glycol(Peg)) prevents tissue growth on one or more portions of the valve. After the bio-degradable material dissolves, tissue growth on the valve closes the valve permanently and thus closes the orifice.
• Optionally, the bio-degradable material dissolves after more than 24 hours, more than 3 days or even more than a week or a month.
• In some embodiments of the invention, the valve is coated by a material which increases tissue growth, such as vascular endothelial growth factor (VEGF). Alternatively, the valve has rough surfaces which encourages tissue growth. The surface and/or materials that induce tissue growth are optionally coated by the bio-degradable material, such that they do not come in contact with tissue until the bio-degradable material has dissolved. The inducement of tissue growth may be on moving parts of the valve, for example, in order to quickly disable the valve, or on non-moving parts, possibly allowing more time until the orifice closes permanently.
• Alternatively or additionally, the bio-degradable material forms a stopper that prevents the valve from closing until it dissolves.
• An aspect of some embodiments of the present invention relates to a method of closing an orifice within a heart. The method includes diagnosing a patient to determine a desired time and/or rate at which to close the orifice and selecting a valve having a desired closure profile. The selected valve is then implanted in the patient and gradually moves to a permanently closed state.
• In some embodiments of the invention, the rate at which the valve closes is controlled by selecting an amount and/or type of a bio-degradable material which delays the movement of the valve to a permanently closed state. Alternatively or additionally, the rate at which the valve closes is controlled by selecting an amount, location and/or type of a tissue growth enhancement drug. Further alternatively or additionally, the rate at which the valve closes is controlled by selecting dimensions and/or structures of surfaces of the valve. For example, a mesh structure or density may be selected to control tissue growth. Alternatively or additionally, a roughness level of one or more surfaces may be selected.
• In some embodiments of the invention, the valve is used in CHF patients and is adapted to gradually close only if it has not encountered high pressures for over a predetermined time. If, however, the valve encounters high pressures, the flow through the valve washes off beginnings of tissue growth and prevents permanent closure due to tissue growth. Thus, if after a while of operation the patient is cured, the valve closes and is covered by tissue. Optionally, the time for which the valve needs to not encounter high pressures until it closes is a feature of the valve and may be adjusted, for example, by setting the roughness of surfaces of the valve, drug amounts and/or the amount of blood it passes when it does not under high pressures.
• Optionally, in accordance with these embodiments, if although the patient did not suffer from high pressures, a physician determined that it is too early to allow the valve to permanently close, an override mechanism may be applied from outside the patient in order to open the valve, for example using magnetic or RF coupling, and thus restart the counting of the period until closure. Alternatively or additionally, the valve is adapted to open when the patient performs special exercises and/or other activities, which the patient may be instructed to perform to prevent closure.
• Optionally, a kit of closure devices includes a plurality of closure devices which are each marked with an average closure time and/or an opening pressure threshold.
• An aspect of some embodiments of the present invention relates to a method of closing an orifice within a heart. The method includes implanting a valve which is adapted to open and close in the patient's heart and at a later time moving the valve to a state in which it is permanently closed by an external intervention.
• In some embodiments of the invention, the external intervention is performed by magnetic or RF coupling which is used to change the conditions governing the opening of the valve. Alternatively or additionally, the external intervention includes a percutaneous procedure which accesses the valve to change its operation parameters.
• An aspect of some embodiments of the present invention relates to a method of treating an aneurism, for example a septal aneurism. The method includes perforating an orifice in the aneurism and implanting a closure device in the perforated orifice. The closure device strengthens the wall including the aneurism and this avoids the problems associated with the aneurism.
• An aspect of some embodiments of the present invention relates to a delivery tool, for delivering a thin element into a patient. The tool includes a central rod, a partially cut tube and an external channel, which surrounds the rod and tube. Delivering a flat element using the delivery tool comprises confining the flat element between the central rod and the partially slotted tube and delivering the tube within a channel which prevents the tube from expanding and releasing the flat element. When the flat element is at its desired location, the channel is refracted relative to the slotted tube, the tube is allowed to expand and releases the flat element.
• In some embodiments of the invention, the flat element is a springy element which is held forcefully in the tube. Upon release of the tube from the channel, the springy element exits the tube radially relative to a long axis of the elongate tube, perpendicular to the tube.
• In some embodiments of the invention, the delivery tool comprises a percutaneous tool, such as a minimally invasive tool, a catheter or a laparoscope.
• An aspect of some embodiments of the present invention relates to a delivery device for leading an implant including one or more loops into a human body. The delivery device includes one or more protrusions which hold the loop between an inner core and an outer channel. As long as the inner core is within the outer channel, the one or more loops of the implant are held by the protrusion. When, however, the inner core is moved beyond the outer channel, the loops are released from the protrusion.
• In some embodiments of the invention, until release, the protrusions are adapted to engage the loops in a manner which allows both pull and push the implant.
• The implant is optionally mounted into the delivery device in a collapsed state in a manner in which at least portions of the implant are allowed to expand upon release from the channel. In some embodiments of the invention, at least some portions of the implant are allowed to expand without the protrusion releasing one or more of the loops. Optionally, as long as the loop is not released from the protrusion, the expanded portions can be re-collapsed by pulling the implant backwards.
• An aspect of some embodiments of the present invention relates to a method of mounting an implant including one or more arms into a delivery tube. The implant is originally packaged in a separate magazine of a diameter substantially equal to the diameter of the delivery tube. The magazine is optionally inserted into a proximal port of the delivery tube, e.g., a haemostatic valve, and the implant is pushed therein from the magazine to the delivery tube.
• An aspect of some embodiments of the present invention relates to an implant including a plurality of arms, which includes a string or wire connecting between a plurality of the arms. The string is attached to the arms such that pulling on the string collapses the implant and introduces the implant back into a removal tube, which may be a same tube used for delivery of the implant or a different tube.
• In some embodiments of the invention, the implant includes distal and proximal arms and the string connects to each of the proximal arms. Optionally, the string has a central point at which string portions connecting to all the proximal arms meet.
• An aspect of some embodiments of the present invention relates to an implant including a plurality of arms having different lengths. Optionally, the arms define loops which may be held by a delivery device during delivery. In some embodiments of the invention, the implant includes at least three or even at least four arms of different lengths. Optionally, the arms of different lengths are adapted to be included in a single plane in a deployed state of the implant and/or are adapted to be directed in a single direction in a folded state, for delivery.
• An aspect of some embodiments of the present invention relates to a delivery tool for delivering an implant into a human body. The delivery tool includes an outer channel and an inner rod adapted to engage arms of an implant together with the channel. Pushing the rod distally releases the arms when the point at which they are held is pushed beyond the distal end of the channel. The rod is adapted to engage the arms of the implant at different points along the length of the rod's distal portion, such that pushing the rod distally within the channel gradually releases the arms.
• An aspect of some embodiments of the present invention relates to a method of delivering an implant having a plurality of arms in a percutaneous and/or minimally invasive procedure. The method includes separately releasing the arms until a last arm is released and the implant moves into place.
• An aspect of some embodiments of the present invention relates to a delivery tool for delivering an implant including a plurality of arms, the delivery tool including a coil adapted to receive the arms. Rotation of the coil optionally separately releases the arms.
• An aspect of some embodiments of the present invention relates to an implant including a plurality of arms adapted to participate in anchoring the implant to internal body tissue and a flat sheet fixed to the arms. Optionally, the length of the arms is fixed parallel to the sheet. In some embodiments of the invention, the arms are embedded within the skirt.
• In some embodiments of the invention, the implant defines an orifice in the a wall to which it anchors and the sheet does not cover the orifice.
• Optionally, the sheet is coated to prevent tissue growth on the sheet. Alternatively, the sheet is coated to induce tissue growth thereon.
• In some embodiments of the invention, the implant includes a flap that is adapted to close against the sheet, and the sheet serves to protect tissue from the flap's contact as it closes.
• An aspect of some embodiments of the invention relates to a valve adapted to be implanted in internal tissue of a patient. The valve is adapted to open under pressures normally encountered during the cardiac cycle in patients between the right and left atrium, for a first duration of the cardiac cycle and under higher pressures for a second duration of the cardiac cycle different from the first duration.
• Optionally, the valve is adapted to open for a larger percentage of the cardiac cycle under pressures encountered between the right and left atrium in patient's under stress than under pressures in normal conditions between the right and left atrium.
• In an exemplary embodiment of the invention, the valve is adapted to open in a healthy patient for less than 100 milliseconds or even less than 50 milliseconds in each cardiac cycle. In a patient under a high pressure episode, the valve optionally opens for at least 150 milliseconds, 200 milliseconds or even at least 400 milliseconds in each cardiac cycle. Optionally, the valve is adapted to open at a pressure of at least 2 mmHg, 4 mmHg or even at least 6 mmHg. In some embodiments of the invention, the valve is adapted to open at a pressure difference of at least 6 mmHg or even at least 10 mmHg.
• In some embodiments of the invention, when implanted between the right and left atrium, the valve is adapted to pass during the second duration at least 50% more blood than during the first duration. Optionally, during the second duration, the valve is adapted to shunt blood at a rate of at least 600 or even at least 800 milliliters per minute, while during the first duration the valve is adapted to shunt blood at a rate of less than 400 or even less than 300 milliliters per minute.
• There is therefore provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion including a plurality of arms adapted to engage an internal tissue wall of a body from two opposite faces, wherein the anchor portion is configured such that at least one of the arms does not have an entirely overlapping arm on the other side of the wall and an opening portion adapted to define an opening for blood flow through the internal tissue wall, when the anchor portion engages the wall.
• Optionally, the opening portion is adapted to radially expand in changing from a collapsed state to a deployed state. Optionally, a largest end to end extent of the anchor portion in a deployed state is at least twice the largest end to end extent of the opening defined by the opening portion. Optionally, a largest end to end extent of the anchor portion is at least four times the largest end to end extent of the opening defined by the opening portion. Optionally, the opening portion comprises a ring surrounding the defined opening. Optionally, the anchor portion and opening portion are configured to have a low profile of less than 3 millimeters in a deployed state not on a tissue wall. Optionally, the plurality of arms comprise flexible elongate elements and/or petals. Optionally, in the deployed state at least one of the arms does not have an even a partially overlapping arm on the other side of the wall, Optionally, the arms are configured to surround the orifice in a deployed state and wherein most of the arms are neighbored along a line surrounding the orifice by two arms configured to be on an opposite side of the wall.
• Optionally, most of the arms of the anchoring portion do not have arms overlapping them on the other side of the wall, in the deployed state. Optionally, the anchor portion and the opening portion are comprised in a single element. The medical implant optionally includes a mesh mounted on the opening portion.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant optionally includes a valve mounted on the anchor portion in a manner which regulates flow through an opening defined by the opening portion.
• Optionally, the valve is formed together with the anchor portion from a same sheet, wire or tube. Optionally, the valve is at least partially formed from a different material from the anchor portion. Optionally, portions of the implant are covered by ePTFE or polyurethane.
• The medical implant optionally includes a motor mounted on the anchor portion and adapted to control the valve. The medical implant optionally includes a sensor mounted on the anchor portion.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion adapted to attach to internal tissue of a body; and an opening portion adapted to define an opening for blood flow when deployed within the body, which opening has a length of less than 3 millimeters, in which blood passing through the opening comes in contact with the implant.
• Optionally, the anchor portion includes a plurality of arms adapted to be located on opposite sides of the attach to the tissue by including parts adapted to be located on opposite sides of a tissue wall. Optionally, the anchor portion comprises a plurality of elongate elements extending radially from the opening portion, wherein a first group of the elongate elements are adapted to be located on one side of the wall and a second group of the elongate elements is adapted to be located on a second side of the wall.
• Optionally, each of the first and second groups comprises at least three elongate elements. Optionally, at least some of the elongate elements comprise petal and/or hoof shaped elements. Optionally, the anchor portion and opening portion are formed from a single piece. Optionally, the implant has a collapsed state and a deployed state and wherein the opening portion is adapted to apply a radial force when released from the collapsed state. Optionally, the opening portion is adapted to cover less than 20% of the perimeter of the opening it defines. Optionally, the anchor portion is configured to engage a tissue wall such that a length in which blood passing through the opening comes in contact with the implant is less than 1 millimeter thicker than the wall. Optionally, the anchor portion and opening portion are configured to have in a deployed state a low profile of less than 3 millimeters. Optionally, the anchor portion and opening portion are configured to have a low profile of less than 15% of an end to end extent of the anchor portion in a deployed state. Optionally, the anchor portion and opening portion are configured to have a low profile of less than 10% of an end to end extent of the anchor portion in a deployed state. Optionally, in the deployed state, the implant does not include parts within the opening defined by the opening portion, beyond parts of the opening portion defining the opening. Optionally, implant optionally includes a skirt surrounding the opening defined by the opening portion.
• Optionally, the implant includes a closure unit adapted to block blood flow through the opening. Optionally, the closure unit is part of a valve which controls the extent of blood flow through the opening. Optionally, the anchor portion does not include sharp points. Optionally, the anchor portion includes at least one spike adapted to penetrate the tissue.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion adapted to attach to an internal tissue wall of a body; and an opening portion adapted to define an opening in the wall, wherein the implant is configured to have a low profile of less than 5 millimeters in a released state in which it is not subject to external forces.
• Optionally, the implant is configured to have a low profile of less than 12% of its largest end to end length in its released state. Optionally, the anchor portion and opening portion are configured to have a low profile of less than 8% of an end to end extent of the anchor portion in the released state. Optionally, the implant is configured to have a low profile not adding to the thickness of the wall more than a millimeter in a deployed state in which the anchor portion is attached to the wall. Optionally, the anchor portion does not include sharp spikes. Optionally, the anchor portion includes a plurality of arms adapted to be located on opposite sides of the tissue wall and to engage the tissue wall between them. Optionally, the anchor portion and opening portion are formed from a single sheet, tube or wire. Optionally, the implant has a collapsed state and a deployed state and wherein the opening portion is adapted to apply a radial force when released from the collapsed state. Optionally, in the deployed state, the implant does not include parts within the opening defined by the opening portion, beyond parts of the opening portion defining the opening. Optionally, the opening portion is adapted to cover less than 40% of the perimeter of the opening it defines.
• Optionally, the implant is configured to have a low profile of less than 2.5 millimeters in a released state in which it is not subject to external forces. Optionally, the implant is configured to have a low profile of less than 1 millimeters in a released state in which it is not subject to external forces. Optionally, the anchor portion comprises a plurality of arms adapted to engage a tissue wall from opposite sides and wherein in the released state a height difference between the arms is less than 2 millimeters.
• Optionally, the anchor portion comprises a plurality of arms adapted to engage a tissue wall from opposite sides and wherein in the released state the arms intended for the different sides of the wall are in the same plane.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion adapted to attach to an internal tissue wall of a body; and an opening portion adapted to define an opening in the wall, wherein the implant is configured to have a collapsed state in which the implant is contained in a cylinder shape of a first diameter, and a deployed state in which the anchor portion engages the wall and the opening portion has a rest state in which it defines an orifice having a second diameter larger than the first diameter.
• Optionally, the implant is adapted to self expand from the collapsed state to the deployed state. Optionally, the second diameter is larger than the first diameter by at least 50%.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of placing an implant in an orifice in a tissue wall in a body, comprising inserting the implant into the orifice in a collapsed state, releasing the implant so that it engages the tissue wall and allowing the implant to elastically expand while engaging the wall, such that it radially expands within the orifice and expands the orifice. Optionally, the implant expands the diameter of the orifice by at least 20%. Optionally, inserting the implant into the orifice comprises inserting into an orifice in a septum.
• Optionally, inserting the implant into the orifice comprises inserting into an orifice made less than six hours before inserting the implant. Optionally, inserting the implant into the orifice comprises inserting into an orifice existent in the patient for at least a week.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical valve for implant in a human body, comprising an anchor portion adapted to attach to internal tissue of a body, an opening portion adapted to define an opening for blood flow and a single flap adapted to control the amount of blood flowing through the opening defined by the opening portion.
• Optionally, the single flap is adapted to have a closed state in which substantially no blood can flow through the opening. Optionally, the single flap has at least one orifice in the flap which allows flow through the opening even when the flap is in a closed state covering the opening. The valve optionally includes a stopper adapted to prevent the flap from entirely covering the opening defined by the opening portion. Optionally, the single flap has an area at least 10% greater than the cross-section area of the opening. Optionally, the single flap is mounted on an arm with a hinge having a maximal curvature point distanced from the opening defined by the opening portion by more than 0.5 millimeters or even more than five millimeters. Optionally, the single flap is mounted on an arm with a hinge having a maximal curvature point distanced from the opening defined by the opening portion by more than a diameter of the opening. Optionally, the single flap is mounted on an arm with a hinge having a maximal curvature point distanced from a distal point of the anchor portion by more than 1 millimeter. Optionally, the single flap is mounted on an arm with a hinge having a maximal curvature point distanced from a distal point of the anchor portion by more than five millimeters.
• Optionally, the valve is configured to open and close without bending the single flap in an area covering the opening. Optionally, the single flap is coated by a bio-degradable material. Optionally, the single flap is formed of a metal coated by a polymer. Optionally, the single flap is made of nitinol. Optionally, the single flap comprises a frame and a sheet carried by the frame. Optionally, the single flap and anchor portion are formed in a monolithic process. Optionally, the single flap and anchor portion are produced separately and then combined. Optionally, the single flap is mounted on the anchor portion through an arm having a plurality of weak points adapted to serve as hinges. Optionally, the single flap is mounted on the anchor portion through an arm with an angle of at least 30° between the flap and the arm in a closed state of the flap. Optionally, the single flap is mounted on the anchor portion through a plurality of arms.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical valve for implant in a human body, comprising an anchor portion adapted to attach to internal tissue of a body, an opening portion adapted to define an opening for blood flow, a flap adapted to cover at least a portion of the opening; and an arm connecting the flap to a hinge at least 1 millimeter away from the opening. Optionally, the hinge is distanced from the opening by more than 3 millimeters. Optionally, the hinge is distanced from the anchor portion by more than 3 millimeters. Optionally, the flap and arm are formed as a single piece. Optionally, the arm, anchor portion and opening portion are formed as a single piece. Optionally, the arm is folded in a manner which forms a hinge around which the flap opens and closes. Optionally, the arm is adapted to be stretched out during delivery into the patient such that the arm around the maximal curvature point of the hinge has an angle of at least 160°. Optionally, the arm comprises a plurality of arms.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical valve for implant in a human body, comprising an anchor portion adapted to attach to internal tissue of a body, an opening portion adapted to define an opening for blood flow, a flap adapted to controllably cover at least a portion of the opening, a hinge on which the flap moves between an open state and a closed state in which it covers the opening and a movement restrictor separate from the hinge, adapted to restrict the movement of the flap.
• Optionally, the valve is adapted to be delivered into a body in a percutaneous procedure, for example through a catheter. Optionally, the movement restrictor comprises a thin flexible element stretched behind the flap in a manner which limits its movement away from the opening portion. Optionally, the thin flexible element is connected at a plurality of points to the anchoring portion or to a skirt mounted on the anchoring portion. Optionally, the movement restrictor comprises a thin flexible element which connects the flap or an arm connecting the flap to the hinge, to the anchor portion or another element which does not move with the flap. Optionally, the movement restrictor is configured to restrict movement of the flap only if another portion of the valve fails. Optionally, the movement restrictor comprises a tab or sheet.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical valve for implant in a human body, comprising an anchor portion adapted to attach to internal tissue of a body, an opening portion adapted to define an opening for blood flow, a flap adapted to controllably cover at least a portion of the opening and an arm connecting the flap to the anchor portion, wherein the arm is adapted to have an operation state in which it is folded and defines a hinge for the flap and a delivery state in which the arm has an angle of at least 150 degrees at the hinge.
• Optionally, the arm is adapted to have an angle of substantially 180 degrees at the hinge in the delivery state.
• There is further provided in accordance with an exemplary embodiment of the invention, an orifice closing implant, comprising an opening portion adapted to define an opening for blood flow in internal tissue of humans and to hold the opening open; and a cover mounted on the opening portion and covering the opening.
• Optionally, the cover and opening portion are adapted to be delivered together into a patient in a percutaneous procedure. Optionally, the cover is adapted to seal the opening defined by the opening portion. Optionally, the opening portion is adapted to anchor the implant to the internal tissue. Optionally, the cover comprises at least one hole allowing blood flow therethrough. Optionally, the cover comprises a mesh pre-attached to the opening portion.
• Optionally, the cover comprises a material which encourages tissue growth. Optionally, the cover and anchor portion are produced separately and later combined. Optionally, the cover and anchor portion are produced together in a monolithic process. Optionally, the cover and anchor portion are produced from different materials.
• There is further provided in accordance with an exemplary embodiment of the invention, an orifice closing implant, comprising an anchoring portion adapted to connect to tissue within a patient and define an opening for blood flow in internal tissue of humans; and a closing portion adapted to seal the opening upon deployment without the aid of tissue growth, the closing portion and the anchoring portion are adapted to be delivered together into a patient in a percutaneous procedure.
• Optionally, the closing portion has an area at least 20% greater than the opening defined by the anchoring portion. Optionally, the anchoring portion is connected to the closing portion in at least three points.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of closing an orifice in internal human tissue, comprising bringing a closure device to an orifice in a percutaneous procedure; and placing the closure device on the orifice in a manner which seals the orifice immediately upon placement.
• There is further provided in accordance with an exemplary embodiment of the invention, an implant, comprising a valve adapted for implantation in a patient; and a bio-degradable material placed on the valve in a manner which prevents permanent closure of the valve and in a manner which slowly dissolves when the valve is implanted in a patient.
• Optionally, the valve is adapted to be delivered to an internal body organ in a percutaneous procedure. Optionally, the bio-degradable material is adapted to dissolve over a period longer than a week. Optionally, the bio-degradable material prevents tissue growth.
• Optionally, at least one surface of the valve is coated by a drug which enhances tissue growth, and the drug is coated by a bio-degradable material which delays the tissue growth until it is dissolved. Optionally, the biodegradable material forms a stopper which prevents closing of the valve. Optionally, the valve is adapted to move to a permanently closed state due to its interaction with body tissue, after the biodegradable material dissolves.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of closing an orifice in the blood system of a patient, comprising diagnosing a patient to determine a desired closure profile of an internal orifice, selecting a valve responsive to the determined closure profile and implanting the selected valve in the internal orifice, such that after implantation the valve is adapted to open and close and allowing the selected valve to change to a permanently closed state.
• Optionally, selecting the valve comprises selecting a valve having an average time between implantation and permanent closure closest to a desired time for the patient.
• Optionally, implanting the valve comprises implanting in a percutaneous procedure. Optionally, selecting the valve comprises selecting a valve which includes a biodegradable material which delays the movement to permanent closure. Optionally, selecting the valve comprises selecting a valve having one or more surfaces adapted to encourage tissue growth. Optionally, selecting the valve comprises selecting a valve which moves to a permanently closed state if the valve is not opened for at least a predetermined amount of time. Optionally, selecting the valve comprises selecting a valve adapted to change to the permanently closed state not less than a month after implantation.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of closing an orifice in the blood system of a patient, comprising implanting a valve in the patient such that closing the valve prevents passage of blood through the orifice and changing a state of the valve to a state in which it is permanently closed and does not allow passage of blood. Optionally, moving the valve to the state in which it is permanently closed comprises transferring the valve to the permanently closed state at least a week after implanting the valve.
• Optionally, the valve opens and closes a plurality of times before moving to the permanently closed state. Optionally, implanting the valve comprises implanting a valve coated by a bio-degradable material which prevents tissue growth on the valve. Optionally, moving the valve to the permanently closed state comprises having tissue grow on the valve.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of treating an aneurism, comprising identifying an aneurism in a patient, perforating a hole in the aneurism and implanting a closure device in the hole.
• There is further provided in accordance with an exemplary embodiment of the invention, a delivery tool for delivering an implant into a patient in a percutaneous procedure, comprising a central rod, a slotted tube along part of its perimeter at a distal end thereof, mounted on the central rod, the tube being adapted to receive a flat implant part between the tube and the central rod; and an outer channel surrounding the central rod and the tube, the channel being adapted to be retracted relative to the tube, edges of the tube around the cut are adapted to expand the tube when the outer channel is retracted, and allow the flat implant part to exit the tube in a direction perpendicular to the rod.
• Optionally, the tube is cut over between 10-25% of its perimeter along at least a portion of its length.
• There is further provided in accordance with an exemplary embodiment of the invention, a delivery tool for delivering an implant into a patient in a percutaneous procedure, comprising a channel adapted to be placed in a blood vessel of a patient for leading an implant to an internal organ of the patient, an elongate rod adapted to pass into the channel; and a notched head mounted on a distal end of the rod, the head having areas in which its radial size is smaller than the inner cross-section of the channel, such that a wire of an implant can fit between the notched head and the channel and having at least one protrusion which substantially touches the channel, such that a loop of an implant can fit around the protrusion and can be pulled proximally by pulling the rod proximally.
• Optionally, the head comprises at least three protrusions adapted to receive respective loops of an implant. Optionally, the head comprises behind the at least one protrusion a protruding ring, such that a loop head of the implant is caught between the protrusion and the protruding ring and moving the head distally pushes the implant distally.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of delivering an implant in a percutaneous procedure, comprising providing a delivery tool including a channel and internal rod, mounting an implant including arms with loops in the delivery tool, in a manner such that the implant moves distally and radially with movements of the rod and delivering the implant through the delivery tool to an internal body organ; and releasing the implant in the internal body organ.
• Optionally, mounting the implant comprises mounting the loops on a coil shaped wire. Optionally, mounting the implant comprises mounting the loops between protrusions on a distal end of the rod and the channel.
• Optionally, releasing the implant comprises releasing a plurality of anus together. Alternatively or additionally, releasing the implant comprises releasing at least two of the arms separately. Optionally, the method includes diagnosing the patient and selecting the implant responsive to the diagnosis.
• Optionally, diagnosing the patient comprises determining a thickness of a tissue wall in the patient. Optionally, diagnosing the patient comprises diagnosing the patient using the delivery tool. Optionally, selecting the implant comprises selecting an implant having a desired anchor portion responsive to the diagnosis.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of delivering an implant into a patient, comprising providing an implant including an anchor portion, an opening defining portion, a flap and an arm connecting the flap to the anchor portion, mounting the implant with the arm at least partially folded over itself; and inserting the implant with the folded arm into a catheter channel.
• Optionally, the implant is adapted to operate in a first configuration in which the arm is folded over itself, and wherein inserting the implant into the catheter channel comprises inserting with the arm folded at a different point than in the first configuration.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of delivering an implant into a patient, comprising inserting an implant into a magazine having an inner diameter, passing the magazine into a proximal port of a delivery tube having an inner diameter substantially the same as the inner diameter of the magazine and advancing the implant from the magazine into the delivery tube.
• Optionally, inserting the implant into the magazine comprises inserting the implant into the magazine in a folded state in which arms of the implant attempt to expand and are prevented from expanding by the magazine. Optionally, passing the magazine into a proximal port of the delivery tube comprises passing through a haemostatic valve.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion including a plurality of arms and a wire connecting a group of the arms of the anchor portion in a manner which allows folding the group of arms by pulling the wire at a single point.
• Optionally, the anchor portion has a folded state in which it has distal and proximal arms and wherein the wire is connected to the proximal arms. Optionally, the wire is connected to at least three arms. Optionally, the anchor portion is adapted to self expand from a folded state to an expanded state.
• There is further provided in accordance with an exemplary embodiment of the invention, a medical implant, comprising an anchor portion including a plurality of arms adapted to anchor in internal tissue of a patient; and a flat sheet fixed to the arms.
• Optionally, the plurality of arms are adapted to anchor to a tissue wall by having some of the arms located on one side of the walls and others of the arms on the other side of the wall. Optionally, the plurality of arms are adapted to define a passage. Optionally, the flat sheet is adapted to surround the passage but not cover the passage. Optionally, the flat sheet has a disc shape. Optionally, the inner perimeter of the flat sheet is distance from the defined passage by at least 1.5 millimeters. Optionally, the inner perimeter of the flat sheet is substantially leveled with the defined passage. Optionally, the flat sheet is adapted to cover the passage. Optionally, the plurality of arms are adapted to attach to the sheet with their length parallel the plane of the sheet.
• The medical implant optionally includes an additional sheet on an opposite side of the anchor portion. Optionally, the plurality of arms are adapted to attach to the sheet with some slack, allowing for a wavy shaped skirt.
• There is further provided in accordance with an exemplary embodiment of the invention, a method of generating a hole in an internal tissue wall of a patient, comprising puncturing a small orifice in a tissue wall, inserting an expander into the orifice; and applying substantially only radial forces by the expander to expand the hole.
• Optionally, the expander comprises a balloon and/or an implant which is left in the orifice after it is expanded. Optionally, puncturing the small orifice comprises puncturing an orifice having a diameter of less than 2 millimeters. Optionally, applying the radial forces comprises increasing the diameter of the orifice by at least 20% or even by at least 50%.
• There is further provided in accordance with an exemplary embodiment of the invention, an implant for internal tissue, comprising an anchor portion adapted to anchor the valve in a patient and a valve adapted to open for a first percentage of the cardiac cycle when subject to pressures between the left and right atrium of a healthy patient and for a second percentage of the cardiac cycle when subject to the pressures between the left atrium and the right atrium of a patient with a high pressure level. Optionally, the implant is adapted to open for pressures above a threshold which is lower than 7 mmHg.
BRIEF DESCRIPTION OF THE DRAWINGS
• Exemplary non-limiting embodiments of the invention will be described with reference to the following description of the embodiments, in conjunction with the figures. Identical structures, elements or parts which appear in more than one figure are preferably labeled with a same or similar number in all the figures in which they appear, and in which:
• FIG. 1 is a schematic illustration of an anchoring device in a deployed configuration, in accordance with an exemplary embodiment of the present invention;
• FIGS. 2A-2E are schematic illustrations of implant devices, in accordance with other exemplary embodiments of the invention;
• FIG. 3 is a schematic illustration of an implant device, in accordance with another exemplary embodiment of the invention;
• FIG. 4A is a schematic illustration of a valve formed of an anchor device carrying a flap, in accordance with an exemplary embodiment of the invention;
• FIG. 4B is a schematic illustration of an anchor device, in accordance with an exemplary embodiment of the invention;
• FIG. 4C is a schematic graph of operation schemes of a valve, in accordance with various exemplary embodiments of the invention;
• FIG. 5 is a schematic illustration of a flap valve, in accordance with another exemplary embodiment of the invention;
• FIGS. 6A and 6B illustrate an anchoring device, carrying a shunt, in a deployed state and collapsed state, respectively, in accordance with an exemplary embodiment of the invention;
• FIGS. 7A-7C describe a two stage valve, in accordance with an exemplary embodiment of the invention;
• FIG. 8A is a schematic illustration of a valve, in accordance with another exemplary embodiment of the invention;
• FIG. 8B is a schematic illustration of a shunt, in accordance with an embodiment of the present invention;
• FIG. 9 is a schematic illustration of a valve, in accordance with an exemplary embodiment of the invention;
• FIGS. 10A and 10B are schematic illustrations of closure devices, in accordance with exemplary embodiments of the invention;
• FIG. 11 is a schematic illustration of an anchoring device holding a cannula, in accordance with an exemplary embodiment of the invention;
• FIG. 12 is a schematic top view of an implantable flow control device, in accordance with an exemplary embodiment of the invention;
• FIG. 13 is a flowchart of acts performed in implanting an anchoring device in a heart, in accordance with an exemplary embodiment of the invention;
• FIG. 14A is a schematic illustration of anchoring device being mounted into a magazine, in accordance with an exemplary embodiment of the present invention;
• FIG. 14B is a schematic illustration of an anchoring device within a magazine, in accordance with an exemplary embodiment of the present invention;
• FIG. 14C is a schematic illustration of an anchoring device being moved from a magazine to a delivery channel, in accordance with an exemplary embodiment of the present invention;
• FIG. 14D is a schematic illustration of anchoring device within a delivery channel in the vicinity of a wall in which it is to be implanted, in accordance with an exemplary embodiment of the present invention;
• FIGS. 15A-15C are schematic illustrations of a handle of a minimally invasive delivery tool, in a process of implanting an anchoring device, in accordance with an exemplary embodiment of the invention;
• FIG. 16 is a schematic view of a distal end of a delivery tool carrying a valve flap, in accordance with another exemplary embodiment of the present invention;
• FIG. 17 is a schematic illustration of a delivery tool, in accordance with another exemplary embodiment of the invention; and
• FIG. 18 is a schematic illustration of an anchoring device with a removal string, in accordance with an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTSOverview
• FIG. 1 is a schematic illustration of ananchoring device100 in a deployed configuration, in accordance with an exemplary embodiment of the present invention.Device100 is adapted for use within internal organs of a patient, for example in the heart. Anchoringdevice100, as well as the other anchoring device embodiments described hereinbelow, may be used on its own to hold an orifice open or may carry one or more functional devices, such as a valve, a closure device, a tube and/or any other device requiring anchoring within a patient.
• Whiledevice100 is suitable for use in many body organs, it is especially useful for organs which move and endure varying pressures, such as the heart.Device100 is optionally adapted for use in organs which are sensitive to formation of embolisms and is designed to minimize the chances of formation of embolisms.
• Device100 comprises asingle wire102 formed into a plurality of petals104 (marked104A and104B) extending radially from acentral orifice106, defined by an imaginary circle, ellipse or any other shape (e.g., a polygon) connecting curve points112, betweenpetals104.Petals104A are optionally designed to be slightly higher thanpetals104B (in the Z direction inFIG. 1), such that when deployed within an orifice in a wall,petals104A are located on one side of the wall andpetals104B are on the other side of the wall. In some embodiments of the invention, the distance between the planes ofpetals104B andpf petals104A is less than 3 millimeters or even less than 1.5 millimeters. In an exemplary embodiment of the invention, the distance is about 2.5 millimeters. Alternatively, the distance is about 1 millimeter or more. Alternatively,petals104A and104B are included in a single plane, such that the profile ofdevice100 is equal to the thickness of thewire102 or sheet from which the device is produced, for example about 0.3 millimeters or possibly even less than 0.1 millimeters.
• Curve points112 are designed to abut against the walltissue facing orifice106 and prevent the tissue from substantially extending intocentral orifice106. Thus, when located within an orifice in a wall of the heart, the wall is caught betweenpetals104 and is held open by curve points112. Curve points112 are optionally designed to have a relatively large curve radius, so as to better endure the forces applied to wire102 at the curve points. As discussed below, a wire of the same material aswire102 or a different material such as fabric, optionally connects curve points112.
• In some embodiments of the invention,wire102 is formed into its closed shape using two crimpedtubes122 which connect the ends ofwire102 together at two different points, defining anoverlap portion120 between the ends ofwire102. The use of two crimpedtubes122 adds to the stability of the device and locks against torque. Optionally,crimped tubes122 are attached at middle points along the length of apetal104A. Alternatively or additionally,crimped tubes122 may be connected closer to the base or closer to thetip118 of thepetal104A. Further alternatively or additionally, other devices may be added todevice100 to increase its stability and/or a simple attachment at the distal end of the petal is used, as described below with reference toFIG. 2B.Overlap portion120 may optionally also be used to define and/or determine a preferred angle and/or position ofdevice100. Instead ofcrimp tubes122, other methods and/or devices may be used, such as soldering, welding and/or glue bonding.Tubes122 may be made from any suitable biocompatible material, such as nitinol, titanium or stainless steel.
Exemplary Structure and Sizes
• In some embodiments of the invention, as shown inFIG. 1,petals104A andpetals104B are arranged alternately aroundcentral orifice106, such that eachpetal104A is neighbored by twopetals104B on opposite sides. A different arrangement of petals, in which two petals on one side of the wall are not separated by petals on the other side of the wall is described below with reference toFIG. 12.Petals104A and104bare optionally adapted to the side of the wall they are to engage according to their height. Alternatively or additionally,petals104A and104B are adapted to their intended side of the wall by being pre-bent differently as to the configuration they are to have in the deployed state. Further alternatively or additionally,petals104A and104B are adapted to their intended side of the wall by being designed to be folded in a specific direction in delivery.
• As shown inFIG. 1,device100 includes six petals. In some embodiments of the invention, however, the device may have more petals, so as to better define a circular border forcentral orifice106, as a circular shape is better compatible to the body in some cases, for example in not having sharp edges. On the other hand, fewer petals makesdevice100 simpler, possibly allowing easier delivery. Exemplary numbers of petals include between 4 to 20, although more, and possibly fewer may be used under some circumstances. In some embodiments of the invention, the anchoring device includes an even number of petals, optionally half of the petals being intended for each side of the wall. It is noted, however, that anchoring devices in accordance with embodiments of the present invention may have odd numbers of petals, such as 5, 7 or 9 petals.
• Petals104 are optionally sufficiently long to stabilize on a tissue wall (e.g., prevent slippage), while not being too long as in general it is desired to minimize the material inserted into body organs. In an exemplary embodiment of the invention, one or more ofpetals104 is longer than 3 mm, longer than 5 mm, or even longer than 8 mm as measured from curve points112 to their tips radially farthest from the curve points. Possibly, however,petals104 are shorter than 10 mm or even shorter than 6 mm.
• In some embodiments of the invention, all ofpetals104 have a same shape, width and length. In other embodiments, however, different petals have different lengths, widths and/or shapes (for example as shown inFIG. 12). For example,petals104A intended for a first side of the wall (e.g., the right atrium) may be longer thanpetals104B for the other side of the wall (e.g., the left atrium), for example due to different expected pressures. In another exemplary embodiment, one ofpetals104A may be made longer or wider than theother petals104A in order to define a desired orientation ofdevice100. Further alternatively or additionally, one or more ofpetals104 may be made shorter in order to conform to the geometry of the body organ in whichdevice100 is to be implanted.
• As shown,petals104 have a relatively wide base close tocentral orifice106, which narrows toward theirtips118, possibly substantially monotonously. In some embodiments, having a wide base and narrower tip makes it easier to folddevice100 for delivery and for removal, if necessary. Alternatively, as discussed hereinbelow,petals104 may have other shapes. For example,petals104 may have a narrow base which monotonously expands, especially in embodiments including a skirt116 (FIG. 4A below), as the expanding petals may prevent slippage of the skirt during delivery. In another exemplary embodiment of the invention,petals104 have a constant width and/or have an expanded distal end.
• Petals104 are optionally biased to apply pressure toward the wall on which they are placed, so that the wall is firmly caught betweenpetals104A and104B, which serve as a double spring. In addition to making the petals firmly hold the wall, the bias ofpetals104 optionally tensions curve points112 and thus increases the radial force applied by curve points112. Alternatively,petals104 are in a rest state against the wall, so as not to press hard against the wall which may be damaged by too much pressure. In some embodiments of the invention, petals may me curved away of the wall at theirdistal tips118 or may be curved back to pressure the wall attip118. Possibly,petals104 are coated with a material adapted to encourage tissue growth arounddevice100, such thatdevice100 is embedded in the wall, after a while.
• The extent to whichpetals104 are biased, the distance in the axial (Z direction) betweenpetals104A and104B and possibly other parameters ofdevice100, such as the thickness ofwire102, the length ofpetals104 and/or the number of petals, optionally depend on characteristics of the tissue in which the device is to be implanted. The characteristics of the tissue may include, for example, one or more of the thickness of the wall in which the device is to be deployed, the calcium content of the tissue, the electrical properties of the tissue and an extent of scarring of the tissue. In an exemplary embodiment of the invention, a plurality ofdevices100 which differ in their parameter values are produced. The device actually used on a specific patient is selected according to the characteristics of the patient. For example, adevice100 with longer petals and/or a stronger bias of the petals toward the tissue is optionally used for softer tissue from which the device may slip.
• The distance in the Z direction betweenpetals104A and104B is optionally selected according to the thickness of the wall on whichdevice100 is implanted. In some embodiments of the invention, the total thickness ofdevice100, when deployed, is less than 3 millimeters, less than 2 millimeters or even less than a single millimeter. Alternatively or additionally, upon implantation on a wall,device100 extends beyond the wall, on both sides of the wall together, by less than 2 millimeters, 1 millimeter or even less than 0.6 millimeters. The thickness ofdevice100 is optionally less than 3%, 1% or even less than 0.5% of the largest diameter of the area defined by the tips ofpetals104.
Materials and Production
• Wire102 optionally has a circular profile, which does not have sharp edges. Alternatively,wire102 may have any other convenient profile, for example a rectangular or square cross section.Wire102 is optionally thin, having a thickness of less than 1 millimeter, less than half a millimeter or even less than 0.3 millimeters, in order to minimize the amount of foreign material in the patient's body and allow folding into a delivery device. In some embodiments of the invention,wire102 has a thickness of more than 0.1 millimeters or even more than 0.25 millimeters, so that it has sufficient strength to resist tissue pressures in anchoring to a tissue wall. Optionally, over its entire length,wire102 has a same thickness. Alternatively, the cross-section shape and/or thickness ofwire102 may vary over its length, for example to have additional strength at curve points112. In some embodiments of the invention, the variable thickness ofwire112 is achieved in an etching process and/or an electro-polishing process.
• In some embodiments of the invention,device100 is produced from a wire which is bent into the desired shape ofdevice100. Alternatively,device100 is produced from a sheet which is etched or cut into the desired shape. This alternative may be considered advantageous in embodiments in which it is desired to have different stiffness of the wire ofpetals104 in different directions.
• Wire102 may comprise substantially any bio-compatible material, such as nitinol, stainless steel or a flexible hard polymer.Wire102 optionally comprises an elastic springy material, for example a super-elastic material.
• Nitinol has several advantages for use in anchoringdevice100. Its super-elasticity allowsanchor device100 to be collapsed for delivery into a small diameter and nitinol is considered highly bio-compatible.
• Possibly, the outer surface orwire102 is relatively smooth. Alternatively, the outer surface ofwire102 is roughened, for example, in order to induce growth of tissue cells thereon and thus causewire102 to be embedded partially or entirely in the wall. The roughening is optionally performed using any suitable method known in the art, such as applying micronic layers of a porous polymer such as polyurethane by, for example, electrospinning, applying fractal (e.g., ceramic) coatings such as Titanium Nitride (TiN) or Iridium Oxide (Irox) and/or applying other coatings which are used to increase capacitance of electrodes.
• Alternatively or additionally,wire102 is coated with one or more materials that encourage tissue growth and/or with other materials, such as anti-inflammation (e.g., steroids) and/or other drugs, such as a heparin-emitting polymer. The coating or roughening may be added over theentire wire102 or may be added only on parts thereof. In an exemplary embodiment of the invention, only thepetals104 to be located on one side of the wall, e.g., intended to be located in the left atrium are coated. Alternatively or additionally, only the distal ends of the petals are coated, leaving the proximal ends of the petals without tissue growth, such that theorifice106 is not blocked by tissue growth.
• The portions coated are optionally selected in a manner which minimizes inflammation and/or adverse reaction of the body todevice100. In some embodiments of the invention, the portions coated are selected in a manner which is directed to achieve a desired size oforifice106 and/or length of flow throughorifice106.
• In some embodiments of the invention, metallic components ofdevice100, such aswire102 and/orskirt116, undergo processes such as electro-polish and/or passivation, on some or all of the surfaces in order to prevent chemical contamination and/or to prevent exposed surfaces from reacting with the environment. Alternatively or additionally,wire102 is encased in a thin ePTFE (expanded polytetrafluoroethylene) cover, in order to improve the hemocompatibility of the wire without substantially changing its mechanical characteristics.
• Device100 optionally minimizes the amount of foreign material participating in defining an orifice in a patient and coming in contact with the blood stream passing through the orifice. In some embodiments of the invention, less than 20%, less than 15% or even less than 10% of the perimeter of the orifice is covered by parts ofdevice100. For example, an opening of 5 millimeters in diameter has a circumference of about 15 millimeters. Ifwire102 has a thickness of 0.3 millimeters and crossesorifice106 at six curve points112, the total perimeter area covered bywire102 is 1.8 mm, which is 12% of a 15 millimeter perimeter.
• In some embodiments of the invention,device100 does not include pins or spikes which penetrate body tissue, thus being less traumatic to the tissue wall in which the device is implanted. Alternatively, for example in order to provide a better coupling,device100 includes pins or spikes which penetrate the tissue wall.
Additional Embodiments of Anchor Device
• FIG. 2A is a schematic illustration of animplant device200, in accordance with another exemplary embodiment of the invention.Device200 includes eight petals154 (marked154A and154B), arranged intermittently around acentral orifice106, Indevice300, the distal ends of petals154 include a head of increasedsize160, which better anchors the petals on the wall, for such cases in which additional anchoring is required.
• FIG. 2B is a schematic illustration of animplant device220, in accordance with still another exemplary embodiment of the invention.Device220 includes four petals154, such that on each side of the wall there are only two petals. One of the petals has aconnection point212, at which the ends of the wire forming the device are connected.
• FIG. 2C is a schematic illustration of animplant device320, in accordance with still another exemplary embodiment of the invention.Device320 includes threepetals104A, for a first side of a wall on whichdevice320 is mounted, and threethin bars134 for an opposite side of the wall. In an exemplary embodiment of the invention,device320 is implanted in the septum,thin bars134 are located in the left atrium andpetals104A are located in the right atrium. Thus, the amount of material in the left atrium is minimized. In some embodiments of the invention, one or more ofbars134 has apin136 along its length, for example at its distal end, which pin is used to anchor the bar in the septum.
• Device320 includes, in some embodiments of the invention, one ormore drug reservoirs322, for example mounted on one or more ofpetals104A. Thereservoirs322 optionally contain a drug, such as a steroid, which is slowly released from the reservoir according to a predetermined scheme and/or according to instructions from a controller. Alternatively, the drug is contained in a coating of the device.
• FIG. 2D is a schematic view of ananchoring device380, in accordance with an exemplary embodiment of the invention. Anchoringdevice380 comprises acentral ring382, which defines a passage and prevents tissue from entering and occluding the passage. A plurality ofpetals384 extend radially fromring382. Some of the petals extend from anupper side390 of thering382, while others extend from abottom392 of the ring, such thatpetals384 can engage a tissue wall, in which ring382 is positioned, between them. Optionally, unlikepetals104,petals384 are curved along their extent fromring382 to their distal end, in a manner which avoids harsh bends, which may cause breakage and in a manner which increases the pressure of the distal ends ofpetals382 against the tissue wall. In some embodiments of the invention, some or all ofpetals384 define arespective loop386 along their length, for example at their distal end.Loop386 is optionally used for engagement of the petals during delivery.Device380 is particularly suitable for production by laser cutting or etching out of a tube, although other methods of production may also be used.Device380 is considered particularly suited for embodiments in which a tube is carried by the anchoring device, for example a tube having a length of more than 3 or even 5 millimeters.Device380 is sufficiently massive to carry such a tube and its being less foldable is not a concern in view of the tube which it carries.
• Optionally, as shown,ring382 comprises a solid sheet, for example of nitinol or a thermoplastic material. Alternatively,ring382 comprises a net texture, in order to minimize its material content and allow folding during delivery into the patient. Use of a net texture may also serve in anchoringring382 to the tissue.Ring382 optionally has a minimal height, of less than 5 millimeters, less than 3 millimeters or even less than 1 millimeter, in order to minimize the extent of foreign material within the patient and the length of contact between blood flow andring382. Alternatively or additionally,ring382 may be cut or slit, forming an open ring or being formed of a plurality of separate portions. In some embodiments of the invention,ring382 is coated entirely or at specific areas of the ring, with a porous layer which enhances tissue growth. Alternatively or additionally,ring382 defines an internal drug reservoir which gradually releases a drug, for example an anti-inflammatory drug.
• Other symmetric or non-symmetric arrangements may be used for anchoring devices in accordance with embodiments of the invention.
• In the above embodiments, petals intended to be on opposite sides of the tissue wall are not located directly on opposite each other, in order to avoid excess pressure on specific points of the wall. In other embodiments of the invention, petals are located partially or entirely parallel each other on opposite sides of the wall.
• FIG. 2E is a schematic illustration of ananchoring device420, in accordance with another exemplary embodiment of the invention.Device420 includes banana shapedpetals422 and424. As shown, thepetals422 and424 have distal heads pointing clockwise, from a view directed at the petals in font of the wall. Thus, while the portions of the petals close tocentral orifice106 are substantially parallel to each other on opposite sides of the wall, the heads of the petals are not parallel to each other. In some embodiments of the invention, however, the tips ofdifferent petals422 and424 are parallel each other on opposite sides of the tissue wall. Petals of other shapes, such as hoof shaped with a larger distal portion than proximal portion, may be used.
• As with the above described embodiments, thepetals422 may be distributed evenly or unevenly around thecentral orifice106. In addition, there may be the same number ofpetals422 aspetals424 or there may be different numbers ofpetals422 and424.
• FIG. 3 is a schematic illustration of animplant device300, in accordance with another exemplary embodiment of the invention.Device300 includes twoexternal rings302 which are to be located on opposite sides of the wall. A plurality ofbands304 connect between the tworings302 in a manner which pressures the tissue of the wall to keep the orifice in the wall open.Device300 is shown with fourbands304, although fewer or more bands may be used.Bands304 may be formed from the same material asrings302 or may be formed separately from a metal or plastic. Alternatively,bands304 my be formed of a fabric, such as Dacron, ePTFE or PolyUrethane strips.
• Alternatively or additionally tobands304, rings302 may be connected partially or entirely by a sheet of fabric or a mesh.
• In some embodiments of the invention, in addition torings302, an additionalsmaller ring306, which fits into oradjacent orifice106, is included indevice300.
• In some embodiments of the invention, rings302 are elliptical and the longer axis of onering302 is located in a rest state ofdevice300, against the shorter axis of thesecond ring302, This arrangement ofrings302 allows folding ofrings302, by applying pressure alongarrows308, for fitting into a narrow delivery tool, without disturbance between the rings. Alternatively, rings302 are circular or have any other suitable shape.
• FIGS. 1-3 illustrate various embodiments of flat anchoring devices. Combinations and variations of these embodiments may also be used in accordance with the present invention. Further embodiments of anchoring devices are described below, for example with reference toFIGS. 6A and 6B.
Keep Orifice Open
• As mentioned above, the above described anchoring devices may be used on their own to keep an orifice open in internal tissue of humans or animals. For example, in some congestive heart failure (CHF) patients it is considered advantageous to perforate a hole between the right and left atria or between other inner chambers. Implanting of one of the above described anchoring devices holds the orifice open, with minimal intervention.
Valve
• in some embodiments of the invention,device100 carries a valve, which regulates the flow through the open orifice.
• FIG. 4A is a schematic illustration of avalve180 formed of ananchor device100 carrying aflap138, in accordance with an exemplary embodiment of the invention.Flap138 is mounted on anelastic arm135 connected to one ofpetals104A ofanchor device100.Arm135 is optionally pre-configured with abent portion146 serving as a hinge offlap138.Arm135 is adapted to allowflap138 to shift between a closed state in whichflap138 is adjacentcentral orifice106 and an open state in which the flap is distanced from the central orifice and allows flow through the orifice.
• In some embodiments of the invention, askirt116 is mounted onanchor device100 in a manner which protects the tissue wall from recurring strikes offlap138. Awire149 is positioned aboveflap138 in a manner which preventsflap138 from opening by more than an allowed extent.
Skirt
• Skirt116 optionally has a ring shape which surroundsorifice106. Alternatively to a round skirt, a polygon shaped skirt may be used, for example having a number of sides equal to the number ofpetals104 to which the skirt is to be connected. Use of such a polygon shaped skirt is expected to provide a good attachment of the skirt todevice100, when attached to all the petals intended to be on its side of the wall. Thus,skirt116 is kept flat, which provides a better contact betweenskirt116 and the tissue wall. For example, for adevice100 having threepetals104 on each side of the wall, a triangular skirt may be used. Alternatively,skirt116 is attached in a manner which allows some slack, such that the skirt may have a wavy form, which could be better in some cases for achieving a desired tissue growth pattern. In some embodiments of the invention,skirt116 is sufficiently wide and/or thick, optionally, at least 100 microns (e.g. 150 microns) thick, for example to prevent undesired tissue growth thereon and/or to protect against force applied byflap138. Alternatively,skirt116 may be thinner and/or be otherwise configured such that the skirt does not protect from force applied by the flap.
• In an exemplary embodiment of the invention,skirt116 is produced by dipping and has a thickness, withoutwire102, of between about 180-300 microns (e.g., 200 microns). For implanting in the septum,skirt116 optionally has an outer diameter including thecentral orifice106 of at least 0.5 centimeters, 1 centimeter or even at least 1.3 centimeters. Optionally,skirt116 does not extend up tocentral orifice106, under an assumption that this may prevent additional obstruction oforifice106 due to the edges of the skirt. In some embodiments of the invention, in accordance with this option, the inner edges ofskirt116 are distanced from the central orifice by at least 1 millimeter or even at least 2 or 3 millimeters. Alternatively, the inner edges of the skirt reach up tocentral orifice106. Further alternatively or additionally,skirt116 has soft and/or sharp edges to avoid tissue growth.
• In embodiments in whichdevice100 is implanted in the wall between the left and right atria, the skirt is optionally located in the right atrium, which has lower pressures and is less disturbed by such an implant. In other embodiments of the invention,device100 includes two skirts, for both sides of the wall on whichdevice100 is mounted.
• In an exemplary embodiment of the invention,skirt116 is produced from the same material aswire102. In some embodiments of the invention,skirt116 andwire102 are produced together as a single piece, for example in an etching process from a single tube or sheet. In the etching process, different elements are optionally given different thickness. For example,petals104 may be made relatively thick, whileskirt116,arm135 and/orflap138 are made thinner with the same or different thicknesses.
• Alternatively,skirt116 and/orflap138 are produced in a deposit process. For example,skirt116 is optionally produced by depositing a material onwire102. In some embodiments of the invention,skirt116 is formed of nitinol, a suitable polymer or of cloth (e.g., Dacron). Alternatively or additionally,skirt116 comprises polyurethane (PU) and/or ePTFE.Skirt116 and/orflap138 may be produced using any method known in the art, including the methods described in U.S. Pat. No. 7,018,408 to Bailey et al., issued Mar. 28, 2006 and US patent publication 2006/0116751 to Bayle et al., the disclosures of which documents are incorporated herein by reference.
• In another embodiment of the invention,skirt116 is manufactured using a dipping and brushing technique. Optionally, a first skirt layer is dipped on a designated shaped mandrel. After a partial curing process, thepetals104 on the side ofskirt116 are held against the partially cured surface and additional layers of the polymer are applied by brushing to obtain full and smooth embedding of the petals in the skirt.
• In some embodiments of the invention,skirt116 comprises two layers formed of different materials, that are bonded together using any of the methods known in the art. One layer intended to face the wall is rough and/or is otherwise adapted to induce tissue growth and the other layer is optionally smooth and/or anti-thrombosis.
• As shown,petals104B are embedded withinskirt116. In other embodiments of the invention,skirt116 is mounted onpetals104A on the opposite side frompetals1048. In still other embodiments of the invention,skirt116 is located betweenpetals104A and1048.
• Any suitable method may be used to attachskirt116 topetals104A. In some embodiments of the invention, an adhesive is used to connectskirt116 towire102. Optionally, micro pores are drilled inskirt116 at the expected connection points using a laser, in order to increase the effectiveness of the adhesive. In some embodiments of the invention,wire102 is woven throughskirt116, which is made in these embodiments of a suitable material to allow weaving therethrough (e.g., eFTFE). In another embodiment of the invention in which skirt116 is formed from two layers, the two layers are attached to each other withpetals104A between them. In other embodiments of the invention,skirt116 is made of a metal and is welded, crimped or soldered topetals104A.
• In some embodiments of the invention,skirt116 is a substantially solid flat surface. Alternatively, in order to minimize the amount of material,skirt116 partially or entirely comprises a mesh.
• Whileskirt116 is described for use withflap138, in other embodiments of the invention an anchoring device not carrying a valve carriesskirt116 to protect the tissue wall for other reasons, for example to prevent or induce tissue growth. In other embodiments of the invention,flap138 is used withoutskirt116, for example when theanchoring device380 ofFIG. 2D is used.Ring382 ofdevice380 optionally has sharp edges, in embodiments in whichflap138 is mounted thereon, in order to prevent tissue growth on the ring.
• FIG. 48 is a schematic illustration of ananchor device171, in accordance with another exemplary embodiment of the invention. Inanchor device171, rather than limiting the amount of material in the anchoring device to a minimum, twolarge skirts177 and179 connected together at acircle139 surroundingorifice106, are used.Skirts177 and179 are formed of a flexible material which allows minimally invasive delivery. In some embodiments of the invention, skirts177 and179 are reinforced byexternal rings143 and optionally an internal ring atcircle139. Alternatively or additionally, other reinforcement structures are used, forexample device100 or any of the other anchoring devices described above.Inner circle139 optionally has a diameter of at least 3, 5 or even at least 8 millimeters. In an exemplary embodiment of the invention,inner circle139 has a diameter of about 10 millimeters andexternal rings143 have a diameter of about 25 millimeters. Other dimensions may also be used.
• The use of the embodiment ofFIG. 4B is particularly useful when the wall in which the anchor device is embedded is weak and requires extra protection. Optionally, the inner surfaces ofskirts177 and179 which face each other are coated with a growth enhancing coating which induces tissue growth and enhances the bond of the implant to the wall.
Skirt and Flap Coating
• As discussed above regardingwire102,skirt116 is optionally coated on its surface intended to face the wall, with a drug which has desired therapeutic characteristics, such as an anti-inflammatory drug. Alternatively or additionally,skirt116 is made rough or from a highly porous material on its face intended to be directed to the wall, in order to encourage tissue growth and/or better attach to the wall tissue.
• In some embodiments of the invention, bothskirt116 andwire102 are treated using the same materials and/or application techniques. Alternatively,wire102 and/or areas ofskirt116 andwire102 which are subject to high friction and/or extensive surface strain are treated with a porous polymer which endures such strain and friction, while other areas, such as the flat areas ofskirt106 are coated by a fractal coating.
• The other face ofskirt116 is optionally made of a low porous material, optionally sealed or otherwise smooth, to prevent tissue growth thereon and/or adhesion of the flap to the skirt, flap failure or formation of clots. Alternatively, the face ofskirt116 not facing the wall is also coated to some extent, in order to form at least a partial barrier between the skirt and blood flow, in order to reduce coagulation. In some embodiments of the invention, the coating on the face ofskirt116 not facing the wall less induces tissue growth compared to the coating on the other face.
• In some embodiments of the invention, one or more surface ofskirt116 is coated with an anti-inflammatory drug, like steroid to prevent inflammation formation, which may encourage tissue growth. Optionally, this layer is covered with blood diluting drugs, like heparin, to prevent formation of clotting. The release of the drugs may be immediate or slow for a short period of less than an hour, or for a long period of more than an hour, several days, more than two weeks or more.
• Optionally,flap138 is not coated to prevent tissue growth, for example in those embodiments in which it is in movement. Alternatively, for example in embodiments in whichflap138 only moves under special conditions,flap138 is partially or entirely coated to prevent tissue growth. In some embodiments of the invention,skirt116,arm135 and/orflap138 are covered by a thin ePTFE cover to improve their hemocompatibility.
• In some embodiments of the invention in which a ring or other portion of the anchoring device defines the orifice, as illustrated inFIG. 2D, the ring may have a sharp edge in the direction facing theflap138, in order to prevent tissue growth on the ring.
• In some embodiments of the invention,flap138 has a balloon mounted on itssurface facing orifice106. Optionally, the balloon is inflated before insertion into the patient. Alternatively, the balloon is inflated using the delivery tool used in delivering the flap into the patient. Further alternatively or additionally, the balloon is inflated by an osmotic gradient method. The inflated balloon may provide a better sealing oforifice106 and/or cushion the repeated forces offlap138 againstskirt116 or the tissue wall behind.
Flap and Arm
• In some embodiments of the invention, the opening and closing offlap138 depend on the relative pressure between the opposite sides of the wall on whichvalve180 is mounted. The pressure required in order to openflap138 is optionally selected according to the task ofdevice180 and is set, for example, by controllinghinge146 and/or the elasticity ofarm135. Alternatively or additionally, the opening pressure offlap138 is controlled by selecting a desired size of the flap, a suitable material from which the flap is manufactured, the length of arm135 (i.e., a longer arm opens at lower pressure) and the width of the arm. In some embodiments of the invention, the opening pressure ofvalve180 is set by setting the extent of preload of theflap138, e.g., the amount of force applied by the flap againstanchor device100 in its rest state.
• In some embodiments of the invention,flap138 comprises a plastic or nitinol sheet cut into shape. The use of nitinol adds to viewability by medical imaging modalities such as fluoroscopy. In addition, nitinol has a high endurance to movements and can withstand large reoccurrences of opening and closing offlap138, without suffering from substantial fatigue. Nitinol may also facilitate a monolithic design, optionally made from a sheet of the material.
• It is noted, that other materials may also be used, optionally with miniature radio opaque markers to allow visibility in medical imaging methods. Such materials optionally have similar properties as nitinol, although not necessarily the same.
• Alternatively,flap138 comprises a metal (e.g., nitinol) frame, with a plastic or other material sheet held, optionally in tension, by the frame. The plastic or other material sheet may be rigid, flexible or elastic. In some embodiments of the invention,flap138 is formed from the same material aswire102 optionally being produced from a same sheet (e.g., foil), for example using an etching procedure. The thickness offlap138 is optionally selected according to a desired stiffness of the flap. In some embodiments of the invention,flap138 has a thickness of less than 100 microns, less than 60 microns or even less than 40 microns (e.g., 30 microns). Alternatively,flap138 may have a thickness above 50 microns or even above 100 microns.
• The length ofarm135 from the perimeter offlap138 to a maximal curvature point ofhinge146 is optionally at least 0.5 millimeters, at least 3 millimeters or even at least 5 millimeters. In some embodiments of the invention, the length ofarm135 from the perimeter offlap138 to the maximal curvature point ofhinge146 is at least greater than half the diameter offlap138 or is even greater than the diameter offlap138.
• The maximal curvature point ofhinge146 is located, in some embodiments of the invention, beyond the outer perimeter ofanchor device100 in its flat deployed state. Optionally, in these embodiments, the maximal curvature point ofhinge146 is at least 0.5 millimeters, at least 3 millimeters or even at least 5 millimeters beyond the outer perimeter ofanchor device100.
• In some embodiments of the invention,flap138 andarm135 are formed as a single piece of the same material, for example nitinol or a suitable polymer. Alternatively,flap138 andarm135 may be formed of separate pieces, possibly from different materials.
• Alternatively to being connected to an end of apetal104A,arm135 may be connected to skirt116. Further alternatively, instead of mountingflap138 on an elastic arm,flap138 is mounted on a pin hinge which rotates in a pin housing. Optionally, in accordance with this alternative, a spring of any suitable type is used to close the flap after it is opened.
• In some embodiments of the invention, when the condition governing the opening offlap138 is met, it opens to a specific extent, regardless of the pressure difference (i.e., pressure gradient) between its opposite sides or the conditions that caused it to open. Alternatively, the extent of opening offlap138 depends on the pressure between the opposite sides ofdevice180. In some embodiments of the invention, the extent of opening increases linearly with the pressure, from a minimal pressure for whichflap138 opens to a pressure corresponding to a maximal opening extent offlap138. Alternatively, the opening extent offlap138 is a non-linear function of the pressure on its opposite sides. In some embodiments of the invention, a spiral spring is connected to arm135 to govern the opening offlap138. The spiral spring is optionally designed to allow opening to a small extent at low pressure levels but requiring very high pressure, which generally are never reached for large opening extents.
• In the maximal opening extent offlap138, the flap is optionally at an angle of less than 30°, 20°, or even less than 10° relative to thesurface containing petals104. Optionally, in the maximal opening extent,flap138 is at an angle of at least 5° relative to thesurface containing petals104, for example 9°. The strain onarm135 optionally does not exceed 0.5% or even does not exceed 0.3%, in order to avoid wear due to fatigue.
• Optionally, in its maximally open state, the projection offlap138 oncentral orifice106 covers at least 50% or even at least 75% of the orifice. In some embodiments of the invention, at its maximal opening, the area of a surface between the tissue wall and the flap is about equal to the area ofcentral orifice106, allowing maximal flow. Accordingly, for example, the distance (H) from the farthest edge offlap138 to the tissue wall, in the open state, is optionally substantially equal to a quarter of the diameter of the orifice in the wall. Alternatively or additionally, the maximal opening extent offlap138 is selected to be small enough such that it allows a substantially infinite number of openings of the valve without causingarm135 to break.
• In some embodiments of the invention, in the maximal opening state, the rate of flow of blood throughcentral orifice106 is less than 2000 cc/min, less than 1500 cc/min or even less than 1000 cc/min in order to enable a sufficient amount of blood to go through other paths even whenflap138 is purposely and/or inadvertently maximally open. The blood flow rate throughorifice106 is optionally selected to achieve a required pressure drop while maintaining a required cardiac output level.
• In an exemplary embodiment of the invention, whendevice180 is placed in the wall between the left atrium and the right atrium,flap138 is designed to open when the pressure gradient is above a predetermined value, which is not encountered during a normal cardiac cycle of a healthy patient. The opening is optionally designed to pass a sufficient amount of blood from the left atrium to the right atrium in order to alleviate high pressures associated with CHF.
• Alternatively,flap138 is designed to open at lower pressures, even pressures encountered during the normal cardiac cycle of the patient. Optionally, in this alternative, the opening at the lower pressure is for a short duration and/or to a small extent, so that only a small amount of blood passes through the orifice under normal conditions. The opening offlap138 under normal conditions is considered advantageous as it prevents clotting, but does not have a substantial effect on the patient's cardiac output and/or chambers loading or otherwise on the patient's blood flow.
• In some embodiments of the invention,flap138 opens, when the pressure in the left chamber is greater than in the right chamber, even when there is only a small pressure gradient between the sides of the wall. In other embodiments of the invention,flap138 is preloaded, such that it only opens when the pressure gradient is greater than zero, for example at least 1 mmHg, at least 3 mmHg or even about 6 mmHg. In some embodiments of the invention,flap138 is preloaded to open only in response to high pressures, for example pressures above 12 mmHg or even 15 mmHg. Other pressure thresholds may be used according to the characteristics of the specific patient in whichdevice180 is implanted. In some embodiments of the invention,flap138 is produced preloaded with a predetermined pressure by pullingflap138 belowskirt116 at the time of setting the rest state offlap138.
• The pressure gradient at whichflap138 opens to its maximal extent, may be as low as 1 or 2 mmHg or lower, or may be higher, for example at least 5 mmHg, at least 7 mmHg or even at least 10 mmHg. In an exemplary embodiment of the invention,flap138 opens to its maximal extent at a pressure gradient of about 12 mmHg.
• In some embodiments of the invention,flap138 has a slow opening response time, such thatflap138 opens only when the required opening pressure occurs for at least a minimal time, thus avoiding opening due to sporadic short term pressure peaks or pressure peaks occurring for short periods during the cardiac cycle. Alternatively,flap138 has a fast response time which is faster than the heart pulse of the patient, for example less than 100 ms, or even less than 30 milliseconds, such that the valve will open for short periods at frequent pressure spike occasions. In accordance with this alternative, the frequent opening offlap138 is considered advantageous in order to prevent clotting. In an exemplary embodiment of the invention,flap138 has a response rate of about 30 Hz. Optionally, in these embodiments,flap138 opens frequently, e.g., every cardiac cycle, for a short period of less than 100 milliseconds or even less than 60 milliseconds, for example about 30 milliseconds. In some of these embodiments of the invention,flap138 is adapted to allow flow of between 400-600 cc/min, at times in whichflap138 is considered in a closed state, i.e., the heart is not subject to high pressures and the flap only opens for short periods. In some embodiments of the invention,flap138 has a fast closing rate, e.g., less than 15 milliseconds, in order to prevent back flow in the wrong direction.Flap138 optionally has a very low mass and/or spring constant in order to achieve the fast response time.
• Optionally, when the pressures in the heart are normal, no more than 1200 cc/min, no more than 800 cc/min, possibly no more than 600 cc/min or even less than 400 cc/min is allowed to pass throughcentral orifice106. In an exemplary embodiment of the invention, about 600 cc/min is allowed to flow throughcentral orifice106 under normal conditions. In other embodiments, smaller amounts of blood are allowed to flow through the orifice under normal conditions, for example between 200-300 cc/min.
• Alternatively or additionally to setting the opening profile offlap138 to allow passage of a relatively small amount of blood throughorifice106 under normal conditions,flap138 is kept slightly open by, for example, having an orifice or slit inflap138 and/or by havingflap138 not close completely againstorifice106.
• FIG. 4C is a graph which shows the correlation between the pressure onflap138 and the amount of blood shunting throughorifice106, in accordance with various exemplary embodiments of the invention. Afirst line460 shows the flow throughorifice106 whenflap138 is fixed in a substantially closed state in which it leaves only a small opening for blood flow. This may be achieved, for example, by having a stopper keepflap138 always slightly open or have a small window inflap138, which allows continuous shunting of blood even whenflap138 is closed. As can be seen, as the pressure gradient (ΔP) between the chambers on the opposite sides of the wall in which anchor100 increases, the flow through the orifice moderately increases.
• Line462 represents the flow throughorifice106 whenflap138 is held maximally opened regardless of the pressure gradient between the chambers on opposite sides of the wall.
• In some embodiments of the invention,flap138 is set to open only when the pressure gradient ΔP is greater than a threshold value ΔP_th.Line464 represents the blood flow throughorifice106, in one of these embodiments, in whichflap138 entirely closesorifice106 andline465 represents the blood flow in another of these embodiments, in whichflap138 does not entirely prevent blood flow in its closed state.
• The slopes oflines464 and465 are determined by the spring rigidity offlap138. When the spring constant is low,flap138 is easily opened and the lines have a steep slope. In some embodiments of the invention, when it is desired to openflap138 maximally when the pressure on the flap is above threshold value ΔP_tharm135 has a very low spring constant. In contrast, in some embodiments of the invention, a high spring constant is used, which in the graph ofFIG. 4C is represented by a non-steep slope.
• The structure ofdevice100 and flap138 (FIG. 4A) mounted thereon is optionally used to adjust the threshold value ΔP_th, for example by setting the preload extent offlap138 and/or by adding a spring which adds to the pressure required in order to openflap138. In addition, the structure ofdevice100 andflap138 may be controlled in order to set a maximal opening extent offlap138, for example by adding a non linear spring, e.g., a spiral spring, which makes the pressure required to exceed a predetermined opening extent, very high.
• In some embodiments of the invention, threshold value ΔP_this set sufficiently high in order thatflap138 opens only when pressure levels above those normally encountered in healthy patients during the cardiac cycle are encountered. Optionally, in accordance with these embodiments line465 is used, such that blood regularly shunts throughorifice106 and prevents coagulation. Optionally, in accordance with these embodiments, threshold value ΔP_this set to above 8 mmHg or even above 10 mmHg.
• In other embodiments of the invention, threshold value ΔP_this set relatively low, such thatflap138 opens in substantially every cardiac cycle. For example, under normal conditions, the pressure during the cardiac cycle varies between ΔP₁and ΔP₂allowing passage of blood at a rate of between 300-600 milliliters per minute. When, however, the patient suffers from left atrial excess blood pressure levels, the pressure varies between ΔP₁and ΔP₃allowing shunting of blood at a rate of between 800-1200 milliliters per minute. Optionally, in accordance with these embodiments, threshold value ΔP_this set to below 7 mmHg or even below 6 or 5 mmHg.
• In some embodiments of the invention, a physician treating a CHF patient selects a valve with a desired threshold value according to a state of the patient. Optionally, in a patient in which there is an expectance of reoccurrence of high pressures even after the pressures are reduced to a desired level, a valve with a low pressure threshold, for example less than 7 mmHg is used, so that the valve will open periodically even when the patient does not suffer from high pressures. Alternatively, when it is desired that the valve permanently close when the pressures go down, a valve with a high pressure threshold (e.g., above 7 or even above 9 mmHg) is used.
• In some embodiments of the invention,flap138 has a fast response time, which is much shorter than the cardiac cycle of patients. For example, the response time offlap138 is optionally shorter than 100 milliseconds or is even shorter than 50 milliseconds. In accordance with these embodiments, threshold value ΔP_this selected such that the average pressure difference in a healthy patient is below the threshold, but during the cardiac cycle the pressure reaches above the threshold. Due to the short response time,flap138 opens during a partial portion of the cardiac cycle and thus provides washout oforifice106.
• In other embodiments of the invention,flap138 has a slow response time of close to the length of a single cycle of the cardiac cycle. In these embodiments, threshold value ΔP_this optionally selected to be above the average pressure during the cardiac cycle of a normal patient, such that the valve opens only when the patient suffers from a high pressure difference. Optionally, in accordance with these embodiments,flap138 is held constantly slightly open or has a small window, which allows washout of theorifice106. Optionally, in these embodiments, constant leakage due to a small opening can be used to assure proper washout of the orifice.
• Alternatively, threshold value ΔP_this set to be slightly below the average pressure between the right and left atrium in a healthy patient. Thus,flap138 regularly opens during the cardiac cycle in healthy patients, but only small amounts of blood shunt throughorifice106 when the flap opens, because the opening extent is small. When, however, the patient suffers from a high pressure difference,flap138 opens to a greater extent and allows passage of large amounts of blood.
Restriction Wire
• Wire149 (FIG. 4A) is optionally connected between two points onskirt116. Alternatively or additionally,wire149 may be connected between two ofpetals104B.Wire149 optionally preventsflap138 from opening by more than an allowed extent, in order to prevent too much blood from passing throughorifice106 and/or in order to prevent stressingarm135.Wire149 optionally comprises Kevlar, nitinol or any other suitable biocompatible material.
• Alternatively or additionally to wire149, astring151 connectsskirt116 or apetal104B toarm135 in a manner which restricts the maximal opening extent offlap138.
• Alternatively to a restriction wire, a restriction string, sheet or tab may be used.
Another Flap Embodiment
• FIG. 5 is a schematic illustration of aflap valve440, in accordance with another exemplary embodiment of the invention.Valve440 comprises threepetals442 for one side of the tissue wall and threepetals444 for the other side of the wall. The petals have a non-symmetric shape, and are arranged such that they partially overlap on opposite sides of the wall, increasing the pressure applied on the wall, Aflap448, shown as being formed from a frame and internal sheet, is held by a pair ofholders446 which extend substantially perpendicular toorifice106. Ahandle449 is optionally used in delivery ofvalve440 into the patient and/or removal ofvalve440 from within the patient.
• Alternatively toholders446 extending substantially perpendicular toflap448 at the point of their connection in the closed state,holders446 may be connected at a smaller angle, optionally an angle of at least 30°, at least 45° or even at least 60°.
• In other embodiments of the invention, a flap connects to its arm or handle at an angle of less than 30°, less than 20° or even less than 10°.
Other Valves
• Although the single flap valve described above has many advantages, the present invention is not limited to any specific valve, andanchor device100 as well as other embodiments of the present invention may be used with other types of valves, such as a duck valve, a bi-leaflet valve, a tri-leaflet valve and/or a parachute shaped valve. For example, for a leaflet valve, a short tube, with the valve therein, is optionally mounted ondevice100 with the central axis of the short tube coveringcentral orifice106.
• FIGS. 6A and 6B illustrate ananchoring device600, carrying ashunt628, in accordance with an exemplary embodiment of the invention. Anchoringdevice600 includes aring610, which carriesshunt628. A plurality ofbent arms620 and622 which are adapted to clamp between them a tissue wall. Optionally,arms620 and/or622 includeloop elements636 at their distal ends.Loop elements636 provide an attachment mechanism for a delivery system, and also allow for reattaching the arms to the delivery system during a removal or other procedure, if necessary.Loop elements636 optionally also increase the area enduring the force applied by the arms to the wall tissue and may further help to anchordevice600 in place by incorporating scar tissue within the loop area and over a greater surface area.
• In some embodiments of the invention, a circumferential connectingwire634 connects toarms620 forcing thearms620 to move together and thus prevent arms from falling to an opposite side of the wall, as well as to prevent arm entanglement and/or unintentional premature release of one or multiple arms, in release of anchoringdevice600. Alternatively or additionally,wire634 provides structural stability to the distal portion ofdevice600. For example,wire634 optionally prevents one or more ofarms620 from applying excess force against the tissue wall and if necessary prevents one of the arms from migrating through the wall, to the other side of the wall. Optionally,wire634 may be used to collapsearms620 back into their folded state, for example if a release of the arms was not successful and it is desired to perform the release a second time.
• Wire634 is optionally formed from an elastic material, such as nitinol or a polymeric material.
• Alternatively to including asingle loop element636 at its distal end, some or all ofarms620 and/or622 may include a plurality (e.g., two) of loops at their distal end. Two loops may be used for example to passwire634 through both the loops.Loops636 may be of substantially any suitable size, optionally having an outer diameter between 1-10 millimeters.
• Further alternatively or additionally, some or all ofarms620 are connected to wire634 using any other connection method, for example, permanently connecting (e.g., welding)arms620 towire634.Wire634 may be connected permanently toarms620, or may be connected releasably (e.g., using snaps and/or adhesion), for example, allowing removal ofwire634 afterdevice600 is anchored on the tissue wall.
• The number of arms indevice600 is optionally in accordance with any of the embodiments described above regardingpetals104 indevice100. It is noted, however, that more arms may be required than petals, due to the fact that the petals may be viewed as double arms.FIG. 6A illustrates12 arms, six arms on each side of the device, but more or fewer arms may be used.
• During delivery,device600 is optionally led into the patient held in the orientation shown inFIG. 6B, by channel500 (FIG. 14C), a delivery tool, or any other mechanism. When properly positioned, the device is gradually or at once released anddevice600 assumes its natural state shown inFIG. 6A, engaging the tissue wall. Optionally, in the collapsed state ofFIG. 6B,device600 and shunt628 can fit into a tube of a diameter of less than 24 French, optionally even not more than 18 or 15 French.
• In some embodiments of the invention,shunt628 comprises a same material asanchor device600 on which it is mounted. Possibly,anchor device600 and shunt628 are formed from a single sheet or tube of material using cutting or etching.
• Whileshunt628 is described in conjunction with anchoringdevice600, it is to be understood that it may be mounted on, or produced with, any of the other anchoring devices described herein.
• Shunt628 optionally comprises a valve, which regulates the flow of blood through the shunt. The valve ofshunt628 may operate in accordance with any of the opening schemes described above regardingflap138 and/or any other opening schemes known in the art. Substantially any type of valve known in the art may be used, including both active and passive valves, for example, a disc attached to a spring, or a leaf opening. Examples of valves and operation patterns which may be used are described more fully in U.S. Patent publication US 2002/0173742, filed Apr. 20, 2001, in U.S. Provisional application 60/573,378, flied May 24, 2004, and in U.S. Patent Publication US 2005/0148925, filed Jul. 7, 2005, the disclosures of all of which are incorporated herein by reference in their entireties.
• FIGS. 7A-7C describe avalve660, which is mounted onshunt628, in accordance with an exemplary embodiment of the invention.Valve660 comprises aframe662, which supports ashunt cover664 mounted on the frame through a pair ofsprings666 and668. Astopper665 optionally preventsspring666 from expanding towardcover664 and compressingspring668. Absent pressure throughshunt628 ontocover664, cover664 entirely prevents flow of blood through the shunt. Alternatively, cover664 in the closed state only allows passage of a small blood volume. When, however, the pressure increases to above a first threshold,spring668, collapses, opening a small blood passage, as shown inFIG. 7B. Optionally, whenspring668 is collapsed, blood at a rate of between about 300-600 milliliters per minute can pass throughshunt628. Alternatively or additionally, the collapse ofspring668 moves cover664 away from the edge ofshunt628 by less than 2 millimeters, less than 1 millimeter or even not more than 0.5 millimeters. If the pressure increases to above a second threshold, higher than the first threshold, also spring666 gives way, as shown inFIG. 7C, allowingcover664 to move farther fromshunt628 and allowing a much larger amount of blood to pass through the shunt. Optionally, the collapse ofspring666 allowscover664 to move at least 3 millimeters, at least 5 millimeters or even at least 7 millimeters away from the edge ofshunt628. In some embodiments of the invention, the compressing ofspring666 allowscover664 to move between 9-12 millimeters away from the edge ofshunt628.
• In some embodiments of the invention, the force required to compressspring668 is selected to be lower than the peak pressure during a normal cardiac cycle of the patient in which shunt628 is implanted, such that in substantially everycardiac cycle cover664 opens and allows flow of a small amount of blood which is believed to prevent blood clotting inshunt628.Spring666 is optionally selected, on the other hand, to require a pressure above the highest pressure normally appearing in the cardiac cycle, such thatspring666 is compressed only at clinically high pressures, such as occurring in CHF patients. Optionally, for each patient, aspecific shunt628 is selected from a plurality of shunts having springs of different force profiles, according to the patients specific characteristics.
• Alternatively to only two springs,valve660 may include three or even more springs, in order to implement a more complex opening profile.
• Frame662 is shown as including foursupport members669 but may include more or fewer members or may be replaced by any other structure, such as a net.
• FIG. 8A is a schematic illustration of avalve670, in accordance with an exemplary embodiment of the invention. Invalve670, the coil springs666 and668 ofvalve660 are replaced by one or more thinspringy elements676 and aspringy tube675, which is compressed at protrudingportions678 only under high pressures. Thinspringy elements676 have a fraction of the thickness ofspringy tube675, for example between 0.3 to 0.5 of the thickness.Springy tube675 and thinspringy elements676 are optionally comprised of Nitinol or another shape memory alloy. Thinspringy elements676 are optionally bendable up to 90 degrees, and require less force for bending than protrudingportions678 ofspringy tube675. Under low pressures,springy elements676 give way and allow passage of a small amount of blood. Under high pressures,springy tube675 collapses and gives way for larger amounts of blood.
• FIG. 8B is a schematic illustration of ashunt700 in accordance with another embodiment of the present invention.Shunt700 includes aframe702 and aninner membrane714.Membrane714 is comprised of flexible material, such as Dacron.Frame702 is open at aproximal end703 and adistal end704, butmembrane714 can be compressed and block flow of fluid throughshunt700. A first spring mechanism includinginner spring arms712 and a second spring mechanism includingouter spring arms710hold membrane714 in a closed position, and can be outwardly compressed, releasingmembrane714, thereby providing an opening for the flow of fluid therethrough. At small pressure differentials,inner spring awls712 may be pushed outwardly until they hitouter spring arms710. At higher pressures, such as during a CHF event, inner andouter spring arms710 and712 are pushed further outwardly,opening membrane714 further, to allow for a greater amount of blood to pass throughshunt700.
• FIG. 9 is a schematic illustration of avalve930, in accordance with an exemplary embodiment of the invention.Valve930 is shown as being mounted on an anchor device similar todevice171 ofFIG. 4B. Invalve930,skirts931 and932 are intended to capture a tissue wall between them. Arim933 connects theskirts931 and932 and defines a blood passage between them. A cover935 (corresponding to flap138) mounted on acompressible rod936 serves as a flap which controllably blocks flow throughrim933. Optionally, a plurality ofmembers937 connected to skirt932, supportcompressible rod936.Valve930 may have any of the opening profiles discussed above regardingflap138, including preload embodiments in which the rest point ofcover935 is belowskirt932 and even possibly belowskirt931.
• Alternatively or additionally torod936 being compressible,members937 provide elasticity allowing movement ofcover935. Cover935 is mounted in accordance with this alternative on a plurality of members (or arms), optionally at least three arms.
• It is noted that the valve arrangement ofvalve930 does not necessarily need to be mounted oncontinuous skirts931 and932, but rather may be mounted on other anchors, such asanchor100. In some embodiments of the invention,anchor100 is embedded withinskirts931 and/or932.
Closure Device
• The above described anchor devices may also be used to carry a closure device for sealing undesired orifices in internal tissue walls of humans. For example, instead offlap138 being mounted oncentral orifice106 in a manner which allows opening of the orifice for flow,flap138 may be mounted overcentral orifice106 permanently or any other cover may be mounted on the anchoring device to coverorifice106. Similarly, the other embodiments of anchor devices and valves described herein may be used with minimal changes in construction of closure devices.
• FIG. 10A is a schematic illustration of aclosure device726, in accordance with an exemplary embodiment of the invention.Device726 comprises an anchoring portion formed frompetals104A and104B and aclosure portion198, which seals an orifice defined bypetals104.Closure portion198 is optionally substantially larger than the area oforifice106, for example having an area at least 10%, 20% or even at least 40% greater thanorifice106. Such a large closure portion achieves a substantially immediate closure of the hole upon deployment and there is no need to wait for tissue growth to achieve the seal.
• FIG. 10B is a schematic illustration of aclosure device273, in accordance with another exemplary embodiment of the invention.Closure device273 comprises aclosure portion198 and a plurality of anchoringarms271 adapted to engage tissue between thearms271 andclosure portion198. Alternatively, alower portion281 ofarms271 may extend sufficiently long, such that wall tissue is caught between the ends ofarms271.
• In some embodiments of the invention,arms271 extend beyond the outer perimeter ofclosure portion198. Alternatively,arms271 are shorter. As shown,arms271 are located relatively close to the outer perimeter ofclosure portion198. Alternatively,arms271 may be located in the center ofclosure portion198, adjacent each other.
• While two arms are shown,closure device273 may include more arms, possibly at least four or even at least six arms. The arms are optionally elastic, for example formed from a suitable polymer or metal. In some embodiments of the invention, the arms are pre-shaped in an open state which engages tissue and are delivered in a folded state. Upon release, the arms engage the tissue wall. Alternatively, the arms are bent by a delivery tool into their engaging state.
• Alternatively or additionally,closure device273 may include one ormore pins277 which engage tissue by penetration therein.
• In an exemplary embodiment of the invention, in treating an aneurism, for example in the septum, an orifice is perforated in the aneurism and a closure device is implanted in the orifice, to strengthen the wall suffering from the aneurism.
• The closure devices may be produced using any of the methods discussed above regarding theskirt116 andflap138, for example using nitinol, stainless steel and/or thermoplastic polymers. In some embodiments of the invention, a closure device as inFIG. 10A orFIG. 10B is produced as a monolithic unit from nitinol or a polymer.
Gradual Closure
• In some embodiments of the invention, valve180 (FIG. 4A) is used to achieve a gradual closure device.Flap138 is set to require a very large pressure in order to open, thus keeping it permanently closed absent an additional opening force. A bio-degradable stopper optionally holdsflap138 open, until it dissolves. Alternatively or additionally,skirt116 and/or other surfaces ofvalve180 are coated with a bio-degradable material, which prevents tissue growth. Once the bio-degradable material dissolves, tissue begins to grow onskirt116 until the tissue growth causesvalve180 to be permanently closed. In some embodiments of the invention, beneath thebio-degradable material skirt116 has a tissue growth enhancing drug, in order to speed up the tissue growth. Alternatively or additionally, the smoothness ofskirt116 and/or other surfaces ofvalve180 are selected according to a desired closure time. Further alternatively or additionally,closure device726,closure device273 or a variation thereof is used with a mesh instead ofclosure portion198. The density of the mesh optionally determines the time between implant and achieving the complete closure, possibly together with other parameters, such as anti-coagulation drug administration.
• The time during which the material keeping the flow path open dissolves is optionally selected according to the needs of the patient. In an exemplary embodiment of the invention, the time passing until the flap permanently closes is at least a week or even at least 2 or 3 weeks.
• The bio-degradable material may include, for example PEG (Poly Ethylene Glycol), although other materials may be used.
Cannula Carrier
• FIG. 11 is a schematic illustration of usinganchoring device100 to hold acannula570, in accordance with an exemplary embodiment of the invention.Cannula570 may be held, for example, in theinter-atrial septum310 for draining blood from the left atrium to the arterial system, for example as part of a cardiac assist device. Alternatively,device100 may be used in holding tubes in other locations, for example a tube leading from the left atria to the right atria.
• Valve with Controller
• FIG. 12 is a schematic top view of an implantableflow control device280, in accordance with an exemplary embodiment of the invention.Device280 comprises threepetals154A adapted to be located on one side of a wall and threepetals154B adapted to be located on another side of the wall.FIG. 12 illustrates thatpetals154A and1548 may be of different lengths and that each twopetals154A may be separated by a plurality ofpetals154B. In this arrangement, points174 betweenpetals154A and154B serve to prevent wall tissue from entering the central orifice, whileproximal points172 betweenadjacent petals154B do not serve in preventing tissue from extending into the central orifice, since thepetals154B on both their sides are on the same side of the wall. Whilepoints172 do not add to the functionality ofdevice180 upon implantation, they optionally add to the anchoring of the device when tissue begins to coverdevice180.FIG. 12 further illustrates aflap138 mounted on ahinge147 which serves as a valve,sensors142 and144, amotor196 and acontroller192.
• In some embodiments of the invention, the opening and closing offlap138 is controlled by acontroller192, which controls the opening and closing according to predetermined settings and/or according to readings of one or more sensors, for example any of the sensors detailed hereinbelow.Controller192 optionally controls the valve using any method known in the art, such as using an electromagnet and/or amotor196. The sensors may be locatedadjacent device180, or may be remote from the device. In some embodiments of the invention,controller192 allows a human operator to provide override commands which open, close or otherwise set the state offlap138, without relation to the predetermined schemes for opening and closing the flap. The override commands may be provided, for example, through wires leading along the patient to a surface port on or beneath the patient's skin. Other methods of externallycontrolling flap138 include magnetic and/or RF coupling. Operation energy may be provided tocontroller192 by an embedded battery and/or by an external source. In some embodiments of the invention, an anchor device is coupled to a pacemaker or ICD and shares with its power source.
• The control may be performed according to any of the schemes known in the art and/or any of those described in US patent publication 2002/0173742, filed Apr. 20, 2001 and/or PCT publication WO 2005/074367, filed Feb. 3, 2005, the disclosures of which patent documents are incorporated herein by reference. For example, the opening offlap138 may depend on the absolute pressure in one or more of the chambers of the heart, on the temperature in one or more chambers of the heart, on the patient's blood pressure and/or on the patient's blood oxygen content. The control may also depend on any of the parameters used by pacemakers, for example in synchronized pacing.
• In some embodiments of the invention,device180 may include apump194, which aids in passing blood through the central orifice, for example under instructions fromcontroller192. Possibly, pump194 and/ormotor196 are used in the normal operation ofdevice180, substantially everytime flap138 is opened or opened to a large extent. Alternatively, pump194 and/ormotor196 operate responsive to sensors that identify thatflap138 did not sufficiently open. Further alternatively, pump194 and/ormotor196 are used substantially only to override the normal operation offlap138 according to external human instructions. Alternatively to the override being performed by an internal device (e.g., motor196), possibly battery operated, the override is performed by an external device, for example by magnetic external control.
Sensors
• Device280 further illustrates the mounting ofsensors142 and144 on the implanted device. As shown, afirst sensor142 is mounted onpetal154A and is located on one side of the wall, while asecond sensor144 is mounted onpetal154B, located on the other side of the wall. Thus, readings from both ofsensors142 and144 may be read and compared in order to determine the relative conditions on opposite sides of the wall. In an exemplary embodiment of the invention,sensors142 and144 comprise one or more temperature sensors and the relative temperature is used to determine the flow pattern of blood in the patient or any other characteristic of the patient's state. Alternatively or additionally, any other sensors may be used and more or fewer sensors may be mounted ondevice180. For example, the sensors may include one or more pressure sensors, oxygen (O₂) sensors, B Natriuretic Peptide (BNP) sensors, a sensor of toxic components, flow sensors and/or pH sensors.
• In some embodiments of the invention, the readings ofsensors142 and/or144 are used bycontroller192 or an external controller, in directly determining whenflap138 is to be opened/closed. Alternatively or additionally,controller192 or any other controller, monitors the health state of the patient using readings of one or more internal and/or external sensors, and accordingly sets the opening profile offlap138 as a function of the pressure difference. Optionally, when it is determined that the patient has recovered entirely, or when otherwise advantageous,controller192 instructs the valve to remain closed permanently. Possibly, when necessary,controller192 changes the minimal or maximal pressure required to open the valve. In an exemplary embodiment of the invention, when the state of the patient deteriorates, the amount of blood allowed to flow through the valve in its “closed” state is decreased. In other embodiments,controller192 may respond in other ways to the patient deterioration, according to the specific medical intervention considered best for the patient.
• Alternatively or additionally, the readings of the sensors are transmitted to a monitoring station outside the patient's body, using wire and/or wireless transmission methods, for example using any of the methods in the above described patent publications US patent publication 2002/0173742, filed Apr. 20, 2001 and/or PCT publication WO 2005/074367, filed Feb. 3, 2005.
Exemplary Deployment Method
• FIG. 13 is a flowchart of acts performed in implanting an anchoring device (e.g., device100) in a heart in a minimally invasive procedure, in accordance with an exemplary embodiment of the invention.Device100 is optionally delivered to the heart on a delivery device, through a peripheral vein or artery, such as the femoral vein or the right or left jugular veins in animals, or the right or left subcalvian in humans.
• If not already existent, an orifice is optionally formed (400) in a wall of the heart, at a required location. In an exemplary embodiment of the invention, the orifice is created using a transeptal puncture tool, for example one including a needle and a dilator catheter. In some embodiments of the invention, the orifice is gradually enlarged, for example with a series of diameter increasing dilators and/or with a non-compliant balloon, until it reaches the desired size for the anchoring device used. The balloon may be provided on the delivery tool of the anchor or on a different tool. Alternatively, when a self expanding device, such asanchoring device100, is used, gradual enlarging is not required and the entire medical procedure is shorter. The orifice may be formed in muscle but is preferably formed in a membrane which is easier to perforate. Whiledevice100 may be used to expand the orifice in which it is implanted, in some embodiments of theinvention device100 does not expand the orifice and the expansion is performed using dilating methods known in the art.
• Alternatively, the device is implanted in an existing orifice, for example in place of an inoperative natural valve and/or in an undesired orifice for example in order to close the orifice or to monitor the flow therethrough.
• In some embodiments of the invention, the orifice is created in the patient immediately before the implantation of the anchor device, for example less than six hours, two hours or even less than 30 minutes before the implantation. Alternatively, the anchor device is implanted in the patient more than a day, more than a week or even more than a month after the orifice was created and/or identified.
• Thedevice100 is provided (402) in a folded state mounted on a distal end of a delivery medical tool. The minimally invasive tool is then inserted (404) into the patient and the device is brought to the orifice into which it is to be implanted. Optionally, the position of the device is accurately adjusted (406) and/or the device is rotated, until the device is in place, within an orifice in a wall, for example between two heart chambers. The device is then released (408) from the delivery tool and optionally self opens into its open state, such that some of the petals are on one side of the wall and some are on the other side of the wall.
• In some embodiments of the invention,device100 continues to expand (410) in place with curve points112 radially pushing against the tissue of the wall and expanding the orifice. Thus, the size of the orifice is radially increased, reducing the chances of trauma from shear forces in forming the orifice. Possibly, the formed orifice has a diameter of less than 4 millimeters, less than 3 millimeters or even less than 2 millimeters and the expansion of the device increases its diameter by at least 20%, 40% or even at least 60%. Alternatively or additionally to self expanding, the anchoring device may be expanded by a balloon, possibly a balloon delivered on the same delivery tool as the anchoring device or on a different tool guided on a same guide wire as the delivery tool of the anchor device. Further alternatively, any other method of generating the orifice may be used.
• The implanting ofdevice100 in the heart is optionally performed while the area is imaged by a real time imaging modality, such as Intracardiac Echo (ICE), Angio and/or Trans-esophageal Echocardiogram (TEE). In some embodiments of the invention, crimpbar120 and/or any other marker (e.g., radio-opaque marker) is used to aid in properly orienting and/orpositioning device100 in place. Radio-opaque markers, when used, are optionally positioned at extreme locations of the anchoring device, for example at the most radially distal points and/or the most radially inner points.
• As described below, the medical delivery tool is optionally designed such that the device may be moved back and forth as much as required for accurately adjusting (406) the location of the device. Possibly, once the device is released in place, it cannot be easily removed.
Device Release
• In some embodiments of the invention, the release of the device is performed all at once, such that all ofpetals104 open from their folded state substantially concurrently. Alternatively, the release is performed gradually, in a plurality of steps. In an exemplary embodiment of the invention,petals104 of a distal side of the wall from the direction in which the delivery tool approaches the orifice (referred to herein without loss of generality aspetals104A) are released first, and thereafter thepetals104B of the proximal side of the wall are released. In other embodiments of the invention, each of the petals is held separately and released separately, for example as described below with reference toFIG. 17 and/or in U.S. provisional applications 60/761,192, titled “Delivery System for Flow Regulation Device”, filed Jan. 23, 2006 and 60/777,315, titled “Arm Configuration for Flow Regulation Device”, filed Feb. 28, 2006, the disclosures of which documents are incorporated herein by reference. In an exemplary embodiment of the invention,device100 is folded non-symmetrically, so that each petal is released separately.
• Device100 is optionally preset in the open state, such that absent an external force it moves to and remains in the open state, using spring loading, pre-shaping, heat shrinking or any other method known in the art. Possibly,device100 is elastically packaged, such thatpetals104 spread out on their own when released from the delivery tool. Alternatively or additionally, external forces are used to induce the spreading out of the petals, for example an externally applied magnetic force. Further alternatively or additionally, a force applied through a minimally invasive tool, such as a catheter balloon, is used to expanddevice100 to its open state.
Exemplary Delivery Mechanism
• FIG. 14A is a schematic illustration of anchoringdevice100 being mounted into adelivery tool490, in accordance with an exemplary embodiment of the present invention.Delivery tool490 comprises an outer channel500 (FIGS. 14C and 14D), acore502 and arod506, adapted to push and pullcore502 withinouter channel500. InFIG. 14A,device100 is partially inserted into a proximal side of amagazine509 in a folded shape having a small diameter convenient for leading into the patient in a minimally invasive tool. Optionally,magazine509 has a size of less than 18 French, less than 15 French or even less than 12 French.Petals104B are inserted distally intomagazine509, aspetals104B are intended to be located on a distal side of the wall on whichdevice100 is mounted. In an exemplary embodiment of the invention, the distal side of the wall comprises the left atrium which is to receive as little as possible foreign materials. Alternatively or additionally, the side of the wall considered as the distal side is selected according to the direction in whichdelivery tool490 is brought to the vicinity of the wall.
• In some embodiments of the invention,core502 comprises a stiff material sufficiently hard to engagepetals104, but not too hard so as not to damage delicate surfaces with which it may come in contact, such as ceramic and/or oxidized surfaces ofskirt116,arm135 or flap138 (FIG. 4A). Optionally, the material ofcore502 has low friction withchannel500, and is suitable for acute contact with tissue. In an exemplary embodiment of the invention,core502 comprises Delrin, Teflon, Nylon, Pebax and/or any other suitable plastic. Alternatively,core502 is formed of a metal or alloy.
• FIG. 14B is a schematic illustration of anchoringdevice100 withinmagazine509, in accordance with an exemplary embodiment of the present invention.Core502 comprises a plurality ofprotrusions504, optionally a protrusion for eachpetal104A.Petals104A are placed inmagazine509 in a manner such that they are caught betweenprotrusions504 andmagazine509,protrusions504 allowdevice100 to be pulled proximally withinmagazine509 andchannel500, by pullingrod506 proximally.Core502 further optionally comprises ashelf508 which pushesdevice100 distally withinmagazine509 andchannel500, whenrod506 is pushed distally. In some embodiments of the invention, as shown inFIG. 14B, there is a short extent of axial freedom between pulling and pushingdevice100 bycore502. Alternatively,core502 firmly catchesdevice100 substantially without any axial freedom.
• It is noted thatdevice100 may be provided from a manufacturer already mounted withinmagazine509 or may be mounted by a physician or a medical staff member before the implantation procedure. For example, immediately before (e.g., on the same day, less than an hour before) the implantation procedure, the state of the patient may be determined and accordingly aspecific device100 to be used may be selected and mounted inmagazine509,
• FIG. 14C is a schematic illustration of the transfer ofanchor device100 frommagazine509 tochannel500, in accordance with an exemplary embodiment of the invention. The inner diameter ofmagazine500 is optionally designed to be substantially equal to the inner diameter ofchannel500.Magazine500 withanchor device100 folded within it is inserted into ahaemostatic valve517 of delivery tool490 (FIG. 14A).Rod506 is then pushed forward to moveanchor device100 out ofmagazine509 intochannel500. Thus, the inner diameter ofchannel500 does not need to be large enough to receivemagazine509 and there is more room for foldedanchor device100 and/orchannel500 can have a smaller outer diameter.
• FIG. 14D is a schematic illustration of anchoringdevice100 withindelivery tool490 in the vicinity of awall310, in accordance with an exemplary embodiment of the present invention.
• Optionally,channel500 is inserted into the patient using any method known in the art and thenrod506 is pushed throughchannel500 and brought adjacent anorifice312 in awall310.
• After the distal end ofchannel500 is passed throughorifice312,rod506 is carefully pushed distally for a small extent, sufficient to releasepetals104B from the distal end ofchannel500, but not to an extent which will allowpetals104A to escapechannel500.Petals104B optionally elastically expand to the flat open configuration, which prevents pullingdevice100 proximally fromwall310.Channel500 androd506 are optionally pulled proximally together such thatpetals104B rest againstwall310.Channel500 is then pulled proximally, whilerod506 is held stationary, so as to releasepetals104A from the channel.Petals104A optionally self expand, such thatdevice100 moves to the expanded state shown inFIG. 1. Thereafter,channel500 androd506 are removed from the patient and the implant procedure is complete.
• In some embodiments of the invention, even after petals140B are released,rod506 can be pulled proximally so as to pullpetals104B back intochannel500.
• In some embodiments of the invention, during the insertion,petals104A and/or104B and/or other portions ofdevice100 are covered by a bio-degradable material, such as poly ethylene glycol, which prevents the petals from tangling during the insertion process. Whendevice100 is released fromchannel500, the bio-degradable material is dissolved and the petals open.
• Optionally, if desired to release each petal separately,protrusions504 are located oncore504 at different axial levels and each protrusion catches a different petal. In some embodiments of the invention, one or more protrusions hold a plurality ofpetals104 together.
• Although the above described method may be performed manually by a physician carefully controllingrod506 andchannel500 from their proximal ends, in some embodiments of the invention, a proximal control handle is provided for control of the delivery process, at the proximal end ofchannel500, as is now described with reference toFIGS. 15A-15C.
• FIGS. 15A-15C are schematic illustrations of ahandle550 of a minimally invasive delivery tool, in a process of implanting an anchoring device, in accordance with an exemplary embodiment of the invention. Handle550 includes aproximal channel handle520 which is used to push and pullchannel500. Arod handle530 is used to moverod506 backwards and forwards. In inserting delivery tool490 (FIG. 14A) into the patient, both ofhandles520 and530 are optionally used to pushchannel500 androd506 together into the patient. In order to releasepetals104B from channel500 (FIG. 14C), handle530 is pushed distally into aniche534 withinhandle520, which only allows advancement ofhandle530 withrod506 to an extent, shown inFIG. 15B, which allows release ofpetals104B and notpetals104A. Thereafter, handles520 and530 are pulled proximally together to bring expandedpetals104B againstwall310. Optionally, handles520 and530 may be rotated together, to bringdevice100 to a desired orientation. At this point, it is required to pullchannel500 proximally relative torod506, in order to releasepetals104A. In an exemplary embodiment of the invention, this is achieved, by first opening asafety lock handle538, which allows movement of aback handle540, relative to handle530. Back handle540 is optionally held stationary, whilehandles520 and530 are pulled proximally, so as to pullchannel500 proximally relative torod506 and release petals504A. In some embodiments of the invention, the relative movement ofhandle530 relative to back handle540 is damped by aspring542 which prevents undesired rough movements which may pullpetals104B out of place.
• In some embodiments of the invention,rod506 is not hollow. Alternatively, a hollow channel passes withinrod506, which may be used for passing fluids into and/or out of the patient. For example, a channel withinrod506 may be used for rinsing and/or applying suction to remove air bubbles. In some embodiments of the invention, a channel throughrod506 may be used for passing tools, e.g., a wire, to the vicinity of anchoringdevice100. Optionally,core502 also has a channel defined through it, serving as a continuation of the channel passing throughrod506. In some embodiments of the invention,rod506 comprises a catheter.
• It is noted that the details of the delivery tool may be varied and other types of delivery tools may be used. For example, while inFIGS. 14A-14C eachpetal104 is held by aseparate protrusion504, in some embodiments of the invention fewer protrusions may be used, although less controlling the delivery process.
Delivery of Additional Elements
• Optionally, in embodiments in whichdevice100 carries additional elements, such asskirt116,flap138 and crimpedtube120, these elements are mounted onproximal petals104A, such that they are delivered on the proximal side of thewall310. Optionally,skirt116 is folded intochannel500 betweenpetals104A, such that thepetals104A catch skirt116 between them. Alternatively, the skirt is folded around the petals, from the outside. Further alternatively or additionally, any other delivery methods may be used, for example any of the methods described in above mentioned PCT publication WO 2005/027752.
• FIG. 16 is a schematic view of a distal end ofdelivery tool490, in accordance with another exemplary embodiment of the present invention. InFIG. 16,delivery tool490 is used to deliver ananchoring device100 together withflap138 and arm135 (FIG. 4A). InFIG. 16,delivery tool490 includes in addition tochannel500 androd506, a slottedtube505 which is partially cut out toward its distal end.Flap138 andarm135 are held betweentube505 androd506 spread out on the rod. The use oftube505 protectschannel500 from sharp edges offlap138, for example when it is formed from nitinol.
• The cut outportion507 oftube505 optionally spans over less than the width offlap138, possibly even less than the width ofarm135, such that the edges of the flap (and arm135) come in contact withtube505 rather than withchannel500. In some embodiments of the invention, cut outportion507 spans over at least 40°, 60° or even at least 90° of the perimeter ofrod506. In an exemplary embodiment of the invention,rod506 has a diameter of between about 8-12 French, although smaller or larger sizes may be used.Channel500 optionally comprises a soft material which is simple to produce, use and move against body tissue, but is easily cut by sharp edges. For example,channel500 may comprise PTEE, PEBAX or other polymer materials.Tube505 optionally comprises a more durable material thanchannel500. Alternatively,tube505 is formed from the same material aschannel500, possibly being thicker.
• Whiletube505 is withinchannel500, flap unit189 is held in its flat state, as shown inFIG. 16, and optionally does not substantially come in contact withchannel500. When cut outportion507 oftube505 is pushed distally out ofchannel500, or whenchannel500 is retracted, flap unit189 is allowed to exit through cut outportion507. In some embodiments of the invention, flap unit189 is adapted to bend in a manner in which it narrows and exits through cut outportion507. Alternatively or additionally,tube505 comprises a soft, flexible and/or elastic material, although preferably not as soft aschannel500, and flap unit189 is designed to apply pressure againsttube505. Cut outportion507 optionally expands under the pressure and allows flap unit189 to move radially out oftube505, perpendicular to, and away from,rod506. Once released, flap unit189 optionally sets into its predetermined state in which it is employed. Using a soft material fortube505 additionally allowsflap138 to slightly dig or cut intotube505 and thus stabilizing flap unit189 while it is delivered withinchannel500.
• Alternatively totube505 allowingflap138 andarm135 to exit once it is pushed out ofchannel500, other triggers may be required to causetube505 to allowflap138 to be released. For example,tube505 may be made from a stiff material which softens when cooled or heated. When it is desired to releaseflap138, thetube505 is heated or cooled in order to release the flap unit. Alternatively or additionally, a biodegradable material is used to holdtube505 in a state which prevents release offlap138.
• Alternatively to deliveringflap138 andarm135 spread out flat,valve180 is delivered in a folded state similar to that shown inFIG. 4A. Optionally,flap138 is rolled into a rod which is a continuation ofarm135 andpetals104 withskirt116 are folded over the rolled up flap. In this state,device180 is inserted into a delivery tool for delivery to an internal organ of the patient. In a variation of this embodiment, rather than being folded at the maximal curvature point ofhinge146, during delivery,arm135 is folded during delivery at a point closer toflap138, to prevent the flap for passing through the orifice and getting stuck therein.
Additional Delivery Embodiments
• In the embodiment described above with reference toFIG. 14C, all of thepetals104A on one side of the wall are released together. While this is preferred for some anchoring devices, other devices may have a risk of petal (or arm) entanglement when allowing all the petals to be released together.
• FIG. 17 is a schematic illustration of adelivery tool750 of anchoring device600 (FIGS. 6A and 6B), in accordance with an exemplary embodiment of the invention.Delivery tool750 comprises anouter channel500 and aninner rod506 with a curledwire752 in the shape of a coil at its distal end. Ahandle754 is used to movechannel500 relative toinner rod506 and/or to entirely movedelivery tool750 into the patient. In use, anchoringdevice600, withshunt628 mounted on it, is mounted in its folded state withinchannel500.Proximal arms622 are mounted on curledwire752, curledwire752 passing throughloops636.
• When anchoringdevice600 is properly positioned in an orifice in which it is to be deployed,channel500 is retracted allowingarms620 to expand. Thereafter,rod506 is rotated in a manner which releasesarms622 from curledwire752. The rotation is optionally performed slowly and/or in steps, allowing a physician to carefully determine that a releasedarm622 is properly positioned, before releasing anotherawl622. When all ofarms622 have been released,rod506 andchannel500 are removed together from the patient.
• Rod506 is optionally sufficiently stiff to allow proximal and distal movement relative to channel500. Alternatively,rod506 is only used for proximal movement relative to channel500. On the other hand,rod506 is optionally sufficiently flexible to allow its insertion percutaneously into inner organs of patients, such as the heart.
• Curledwire752 is optionally formed of a strong material, such as nitinol, stainless steel or titanium, which does not deform and change its shape under the pressure ofarms622
• In some embodiments of the invention, all ofarms622 are of the same length. Alternatively, the arms have different lengths, according to their locations on curledwire752. It is noted that other arrangements for gradually releasingarms622 may be used in accordance with embodiments of the invention. For example,arms622 may have different lengths such that gradual retraction ofchannel500 causes separate release of the arms.
• Any of the delivery tools used for the anchoring devices may include in addition to the elements required for the delivery, other tools and/or elements such as working channels, a protective sheath, one or more cameras and/or sensors. Thus, in addition to performing the delivery, the delivery tool may be used to diagnose the patient before or after the implant. For example, immediately before the anchoring device is released, a last minute diagnosis, for example by sensing pressure, blood flow and/or temperature may be performed to by the same delivery tool to determine that the implant procedure is safe. Alternatively or additionally, after the anchoring device is implanted, sensors on the delivery device determine whether there were problems in the implant and if problems were encountered, the anchoring device may be removed, for example as is now described with reference toFIG. 18. In some embodiments of the invention, when a closure device is implanted, a sensor on the delivery tool may determine whether the orifice sufficiently sealed the orifice.
• FIG. 18 is a schematic illustration of ananchor device100 with aretrieval string801, in accordance with an exemplary embodiment of the invention. Aretrieval string801 connectsdistal points118 ofpetals104A to acentral junction802. If necessary, ahook810 is passed through a working channel of the delivery device, or is otherwise brought tocentral junction802 and is pulled proximally so as to foldpetals104A and pull them back intochannel500. In some embodiments of the invention, in order to inserthook810,rod506 is removed fromchannel500. Thereafter,channel500 is advanced to push alsodistal petals104B intochannel500 and removeanchor device100 from the patient.
• Alternatively or additionally,petals104 are long enough to allow attachment of a patch to them from inside the heart, e.g., the right chamber, to aid in the removal.
• Optionally, in embodiments in which an anchoring device carries aclosure portion198,retrieval string801 is connected toclosure portion198. Optionally, inembodiments including flap138, a same string is used for restricting movements of the flap (wire149,FIG. 4A) and for retrieval.
• In some embodiments of the invention,petals104A are inclined towardcentral junction802 in order to allow easier collapse.
• Althoughanchor device100 is described herein as being suitable for insertion in minimally invasive procedures, the anchor devices of the present invention may also be delivered in open surgery and in some embodiments of the invention, anchor devices not suitable for minimally invasive surgery are used.
CONCLUSION
• It will be appreciated that the above-described methods may be varied in many ways, including, changing materials, sizes and shapes. For example, rather than foldingdevice100 in an organized manner,device100 may be packaged by an irregular folding and/or by a collapsing of the device without any preplanned folding scheme. Furthermore,device100 may have a structure which conforms to a wavy or other shaped tissue wall surface.
• It should also be appreciated that the above described description of methods and apparatus are to be interpreted as including apparatus for carrying out the methods, and methods of using the apparatus.
• The present invention has been described using non-limiting detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. It should be understood that features and/or steps described with respect to one embodiment may be used with other embodiments and that not all embodiments of the invention have all of the features and/or steps shown in a particular figure or described with respect to one of the embodiments. Particularly, the delivery tools described for one anchoring device may be used for other anchoring devices. Also, the valves, closure devices and tubes described as being mounted on a specific anchoring device may be mounted on any of the other described anchoring devices and/or combination or variations thereof.
• Variations of embodiments described will occur to persons of the art. Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the claims, “including but not necessarily limited to”.
• It is noted that some of the above described embodiments may describe the best mode contemplated by the inventors and therefore may include structure, acts or details of structures and acts that may not be essential to the invention and which are described as examples. Structure and acts described herein are replaceable by equivalents which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the invention is limited only by the elements and limitations as used in the claims.

Claims (30)

What is claimed is:

1. A shunt for implantation at an atrial septum within a heart, the shunt comprising:

an anchor portion configured to transition from a collapsed state to a deployed state, the anchor portion comprising a first plurality of petals configured to engage, in the deployed state, a face of the atrial septum and a second plurality of petals configured to engage, in the deployed state, an opposing face of the atrial septum, wherein the anchor portion is configured such that at least one of the petals of the first plurality does not have an entirely overlapping petal in the second plurality on the opposing face of the atrial septum; and

an opening portion adapted to define an opening for blood flow through the atrial septum in the deployed state when the anchor portion engages the atrial septum.

2. The shunt ofclaim 1, wherein the anchor portion does not penetrate the atrial septum.

3. The shunt ofclaim 1, wherein the opening portion is configured to radially expand during the transition from the collapsed state to the deployed state.

4. The shunt ofclaim 1, wherein the anchor portion and the opening portion are formed from a tube.

5. The shunt ofclaim 4, wherein the anchor portion and the opening portion are formed by laser cutting out of the tube.

6. The shunt ofclaim 1, wherein the shunt is configured to permit blood flow through the atrial septum via the opening from a left atrium to a right atrium in an amount sufficient to alleviate high pressures associated with heart failure.

7. The shunt ofclaim 1, wherein the shunt further comprises radio-opaque markers.

8. The shunt ofclaim 1, wherein the opening has a diameter in the deployed state of at least 6 millimeters.

9. The shunt ofclaim 1, wherein the anchor portion and the opening portion are formed from a metal frame.

10. The shunt ofclaim 1, wherein the anchor portion and the opening portion are formed from a single piece of nitinol.

11. The shunt ofclaim 1, wherein the first plurality of petals are configured to transition from the collapsed state to the deployed state when deployed in a first atrium and, after deployment of the first plurality of petals, the second plurality of petals are configured to transition from the collapsed state to the deployed state when deployed in a second atrium, to thereby implant the shunt at the atrial septum.

12. The shunt ofclaim 1, wherein each petal of the first plurality of petals has a triangular shape.

13. The shunt ofclaim 12, wherein each petal of the first plurality of petals is configured to lie flat on the face of the atrial septum.

14. The shun ach petal of the second plurality of petals has a triangular shape.

15. The shunt ofclaim 1, wherein each petal of the second plurality of petals is configured to curve towards the atrial septum such that a distal portion of each petal applies pressure to the opposing face of the atrial septum.

16. The shunt ofclaim 1, wherein the first and second pluralities of petals are formed of a super-elastic material.

17. The shunt ofclaim 1, wherein, in the deployed state, at least one of the petals of the first plurality of petals does not have a partially overlapping petal from the second plurality of petals.

18. The shunt ofclaim 1, wherein the first and second pluralities of petals are configured to surround the opening in the deployed state.

19. The shunt ofclaim 1, wherein none of the petals of the first plurality of petals fully overlaps with a petal in the second plurality of petals in the deployed state.

20. The shunt ofclaim 1, wherein the shunt is configured such that the opening remains clear from elements mounted therein.

21. The shunt ofclaim 1, further comprising a valve mounted on the anchor portion in a manner which regulates blood flow through the opening defined by the opening portion.

22. The shunt ofclaim 1, further comprising a sensor mounted on the anchor portion.

23. The shunt ofclaim 1, wherein portions of the shunt are covered by ePTFE or polyurethane.

24. The shunt ofclaim 1, wherein the first and second pluralities of petals are arranged alternately around the opening, such that each petal of the first plurality of petals is neighbored by a petal of the second plurality of petals on one side and another petal of the second plurality of petal on the opposite side.

25. A method for delivering the shunt ofclaim 1, the method comprising:

creating an orifice in the atrial septum of the body via a transeptal puncture tool; and

deploying the shunt within the orifice such that the anchor portion engages the atrial septum and the opening portion defines the opening for blood flow through the orifice of the atrial septum.

26. The method ofclaim 25, wherein the transeptal puncture tool comprises a, needle and a dilator catheter.

27. The method ofclaim 25, wherein deploying the shunt within the orifice comprises percutaneously deploying the shunt such that the opening portion self-expands within the orifice and further expands the orifice.

28. The method ofclaim 27, wherein deploying the shunt comprises percutaneously deploying the shunt such that the first plurality of petals self-expands within a left atrium and, after the first plurality of petals self-expands, the second plurality of petals self-expands within a right atrium.

29. A shunt for implantation at an atrial septum within a heart, the shunt comprising:

a nitinol body comprising a first plurality of petals configured to engage, in a deployed state, a face of the atrial septum and a second plurality of petals configured to engage, in the deployed state, an opposing face of the atrial septum, wherein the nitinol body is configured such each petal of the first plurality of petals does not have an entirely overlapping petal in the second plurality of petals on the opposing face of the atrial septum,

wherein the nitinol body defines an opening for blood flow through the atrial septum in the deployed state when the nitinol body engages the atrial septum.

30. The shunt ofclaim 29, wherein the first and second pluralities of petals are arranged alternately around the opening, such that each petal of the first plurality of petals is neighbored by a petal of the second plurality of petals on one side and another petal of the second plurality of petal on the opposite side.

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