IMPLANTABLE DEVICE TO FORM A CONSTRICTION WITHIN A BLOOD VESSEL LUMEN

A device includes a constricting portion and an anchoring element. The anchoring element anchors the device to an inner wall of a blood vessel. The constricting portion extends from an inlet at a proximal end for receiving blood flow therethrough to at least one outlet at a distal end through which flow is expelled. The constricting portion includes a neck section and tapers from the inlet to the neck section. The tapering defines a space substantially surrounding the constricting portion in which flow expelled from the at least one outlet can freely flow.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to an implantable device to form a constriction in blood vessel and, more particularly, but not exclusively, to an implantable device configured to improve left ventricle (LV) systolic function in patients with congestive heart failure (CHF) based on forming the constriction in a pulmonary artery.

Congestive heart failure (CHF) is a condition in which the heart does not pump out sufficient blood to meet the body's demands. CHF can result from either a reduced ability of the heart muscle to contract (systolic failure) or from a mechanical problem that limits the ability of the heart's chambers to fill with blood (diastolic failure). When weakened, the heart is unable to keep up with the demands placed upon it and the left ventricle (LV) may get backed up or congested. CHF is a progressive disease. Failure of the left side of the heart (left-heart failure/left-sided failure/left-ventricle failure) is the most common form of the disease.

When CHF due to LV systolic failure occurs, it is typically associated with changes in the geometry of the ventricles, often called remodeling. The LV becomes dilated and the interventricular septum is deflected towards the right ventricle (RV), resulting in decreased LV output/pumping efficiency. The efficient systolic function of the LV is dependent not only on the strength of the myocardium but also on the LV geometry, the position and shape of the interventricular septum and the geometry and function of the RV. Interventricular dependence has been documented in experimental studies which have evaluated both normal and pathological preparations from animals. LV systolic function can be directly influenced by interventions affecting the RV and the position of the interventricular septum.

CHF affects people of all ages including children, but it occurs most frequently in those over age 60, and is a leading cause of hospitalization and death in that age group. Current treatments of CHF include lifestyle changes, medications, and surgical procedures, such as to bypass blocked blood vessels, replace or repair regurgitated or stenotic valves, install stents to open narrowed coronary vessels, install pump assist devices or transplantation of the heart.

U.S. Pat. No. 10,667,931 entitled “Pulmonary artery implant apparatus and methods of use thereof,” the content of which is incorporated by reference herein, discloses an implantable apparatus and methods of use thereof to treat congestive heart failure. The implantable apparatus is anchored by implantation of a section of the apparatus within in a branch pulmonary artery, for example the left pulmonary artery, which then positions and anchors another section, for example a device frame section of the apparatus within the main pulmonary artery. A medical device may be attached to the anchored device frame.

U.S. Patent Publication No. 20180085128, entitled “Artery medical apparatus and methods of use thereof,” the contents of which is incorporated by reference herein, discloses a medical apparatus for deployment within an anatomical blood vessel. The medical apparatus disclosed includes a first tubular wall, a second tubular wall within the first tubular wall, and a constricting element that constricts a circumference of a portion of the second tubular wall. The combination of the first tubular wall, the second tubular wall and the constricting element is disclosed to form a diametrical reducer for reducing an effective diameter of an anatomical blood vessel. It is also disclosed that at least a portion of the second tubular wall is coated with a coating material. Example coating materials disclosed include silicone elastomers, urethane containing polymers, polytetrafluoroethylene, polylactic acid, xenograft or allograft tissue (such as pericardial tissue).

U.S. Patent Publication No. 20180085128, entitled “Double walled fixed length stent like apparatus and methods of used thereof,” the contents of which is incorporated by reference herein, discloses a medical apparatus for deployment within an anatomical blood vessel and methods of use thereof. The medical apparatus includes a first tubular wall and a second tubular wall, placed within the first tubular wall. The first and second tubular walls are firmly connected at their edges and restricted to have same overall longitudinal length. The second tubular wall is configured to be partially constricted towards its inner radial axis, while maintaining its overall longitudinal length. It is also described that the method includes at least partially coating the second tubular wall.

SUMMARY OF THE INVENTION

According to an aspect of some embodiments there is provided a device configured to form a constriction in a blood vessel and affect a change in pressure upstream and/or downstream the implantable device based on forming the constriction. Optionally and preferably, the change in pressure is selected to improve LV output in patients with CHF and more particularly in patients with a dilated LV. According to some example embodiments, the device is configured to be implanted within a pulmonary artery and is configured to impose a narrowing of the flow path within the pulmonary artery. Optionally and preferably, the imposed narrowing significantly reduces an effective diameter of the pulmonary artery and/or increases flow resistance within the artery and based on this adjusting affects an elevation in RV pressure. The elevated RV pressure may reposition and support an interventricular septum that otherwise may be deflected toward the RV in CHF patients with a dilated LV.

According to some example embodiments, the device is sized and shaped for placement in the branch pulmonary arteries (right and/or left pulmonary arteries). Optionally and preferably, a desired elevation in RV pressure with the device is affected based on implanting a pair of the devices, e.g. one device in each of the right pulmonary artery and the left pulmonary artery. According to some example embodiments, it is desirable to implant the device proximal to a sub-bifurcation of the left or right branch pulmonary arteries to direct all the flow through the device and therefore avoid diversion of flow through a sub-branch artery upstream of the device. In this manner, all flow through the branch pulmonary arteries may be directed through the device rather than be diverted around the device.

There may be a number of potential advantages associated with implanting bilateral devices in the branch pulmonary arteries as opposed to a single device in the main pulmonary artery. One potential advantage is that the relatively longer length of the branch arteries and the smaller diameters as compared to the main pulmonary artery allow for more favorable length to diameter ratio of the device and provides more surface area for securely anchoring the device within the artery. Another potential advantage is that the branch arteries are spaced away from the pulmonary valve. By spacing the device away from the pulmonary valve, the risk of the device moving toward the pulmonary valve and/or interfering with its operation may be significantly reduced.

When implanting a device within the branch pulmonary arteries there is a risk that the device may be overlaid a sub-branch artery and block flow into that sub-branch artery. Since there is significant variability in location of the first sub-branch arteries among individuals, such a risk would be difficult to mitigate simply by selecting a desirable location along the branch artery for implanting and/or based on limiting a length of the device.

According to an aspect of some example embodiments, the device is configured to support backflow along a length of the device to reduce or avoid the risk of blocking sub-branch arteries that may be present along a length of the device. In some example embodiments, a portion of the device is configured to form a seal between with the inner arterial wall to prevent incoming flow from flowing around the device.

According to an aspect of some example embodiments, there is provided a device including a constricting portion extending from an inlet at a proximal end for receiving blood flow therethrough to at least one outlet at a distal end through which flow is expelled; and an anchoring element configured to anchor the device to an inner wall of a blood vessel; wherein the constricting portion includes a neck section and wherein the constricting portion tapers from the inlet to the neck section and wherein the tapering defines a space substantially surrounding the constricting portion in which flow expelled from the at least one outlet can freely flow.

Optionally, the constricting portion includes a flared section that flares from the neck section to the at least one outlet.

Optionally, the anchoring element is an outer frame defining an outer cylindrical wall with openings through which blood may freely flow.

Optionally, the device further includes an inner frame defining an inner cylindrical wall with openings through which blood may freely flow and a cover partially lining the inner frame, wherein the constriction portion is formed by a first portion of the inner frame that is lined with the cover, the first portion extending from the inlet to the at least one outlet.

Optionally, the inner frame is within the outer frame and oriented in a same direction.

Optionally, the inner frame and the outer frame extends from the proximal end to a frame distal end.

Optionally, the inner frame is fixed to the outer frame at each of the proximal end and the frame distal end.

Optionally, a second portion of the inner frame extends beyond the at least one outlet to the frame distal end of the inner frame and wherein flow expelled from the at least one outlet is free to flow through the second portion of the inner frame.

Optionally, the cover lines 50%-90% of a length of the inner frame.

Optionally, the cover extends to the frame distal end and includes openings at the distal end of the constricting portion and wherein the at least one outlet includes the openings formed through the cover at the distal end of the constricting portion.

Optionally, the cover is a liquid impermeable cover.

Optionally, the cover is a pliable material that is fixed on one or both of an inner surface and an outer surface of the inner frame.

Optionally, a diameter of the neck section is 5 mm-15 mm.

Optionally, the anchoring element is fixed to the constricting portion at the proximal end and further includes a circumferential sealing strip extending around the anchoring element at the proximal end.

Optionally, the circumferential sealing strip lines the anchoring element over a length of 3 mm-10 mm from the proximal end.

Optionally, the constricting portion is lined with a cover and wherein the circumferential sealing strip is connected to the cover of the constricting portion with a liquid impermeable sealed connection.

Optionally, the device further includes a constricting element fitted around the neck section and configured to constrict the neck section to a defined diameter.

Optionally, the constricting portion is formed with the neck section in a neutral state absent the constricting element and wherein the constricting element is configured to further constricts the neck section.

Optionally, the constricting element is configured to maintain the defined diameter while implanted within blood vessel.

According to an aspect of some example embodiments, there is provided an outer frame defining an outer cylindrical wall with openings through which blood may freely flow and configured for being anchored within a blood vessel; an inner frame defining an inner cylindrical wall with openings through which blood may freely flow, wherein the inner frame is within the outer frame, and wherein at least a portion of the inner frame is fixedly attached to the outer frame, the inner frame having an inner frame length that extends from a proximal end to a frame distal end; a cover lining the inner frame from the proximal end to a cover distal end to form a constricting portion, wherein the constricting portion has a length that is shorter than the inner frame length, wherein the cover seals the openings in the inner frame over the length of the constricting portion; a constricting element configured to constrict a diameter of the inner frame along the constricting portion to form a neck section with a defined neck diameter, wherein the constricting portion tapers from the proximal end to the neck section and wherein the tapering defines a space substantially surrounding the constricting portion in which flow expelled from constricting portion can freely flow.

Optionally, the cover lines 50%-90% of a length of the inner frame.

Optionally, the cover is a pliable material that is fixed on one or both of an inner surface and an outer surface of the inner frame.

Optionally, a second portion of the inner frame extending from the cover distal end to the frame distal end is not lined with the cover and is exposed.

Optionally, an edge of the inner frame at the cover distal end is configured to be spaced away from an inner wall of a blood vessel when the device is implanted therein.

Optionally, a diameter of the inner frame at the cover distal end is at least 10% smaller than a diameter of the inner frame at the distal end.

Optionally, the outer frame is fixed to the inner frame at the proximal end and further including a circumferential sealing strip extending around the outer frame at the proximal end.

Optionally, the circumferential sealing strip lines the outer frame over a length of 3 mm-10 mm from the proximal end.

Optionally, a diameter of the neck section is 5 mm-15 mm.

Optionally, the neck section is configured to be opened by inserting a balloon through the constricting portion and inflating the balloon therein.

Optionally, the device is collapsible and configured to be implanted within the blood vessel by transcatheter implantation.

Optionally, the spacing is configured to provide free blood flow into branch blood vessels along a length of the blood vessel in which the device is implanted.

Optionally, the device is configured for being implanted within a pulmonary artery.

Optionally, the device is configured for being implanted in the right or left pulmonary artery.

Optionally, the device is configured for elevating pressure in the right ventricle.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to an implantable device to form a constriction in a blood vessel and, more particularly, but not exclusively, to an implantable device configured to improve left ventricle (LV) systolic function in patients with congestive heart failure (CHF) based on forming the constriction in a pulmonary artery.

According to some example embodiments, the implantable device includes both a constricting portion, e.g., a diameter constricting portion, to direct the flow in the blood vessel through a defined narrowing and an anchoring element to anchor the constricting portion to an inner wall of the blood vessel. The constricting portion may extend between a first opening (an inlet) at a proximal end through which flow in blood vessel is received and at least one second opening (an outlet) at a distal end through which flow is expelled from the device. According to some example embodiments, the inlet has a diameter that is substantially the same as a diameter of the blood vessel when implanted therein and the constricting portion narrows with respect to the inlet. According to some example embodiments, the diameter of both an inner surface and the outer surface of the constricting portion is narrowed in relation to the inlet. The outer surface as defined herein refers to the abluminal surface of the constricting portion that faces the inner wall of the blood vessel (away from the lumen) when implanted therein. The inner surface as defined herein refers to the luminal surface of the constricting portion that faces the lumen within the constricting portion through which the flow in the blood vessel is directed. The shape and extent of the narrowing of the outer surface may be the same or different than that of the inner surface.

According to some example embodiments, the narrowed diameter of the outer surface is configured for defining a volume around the outer surface through which blood may flow to feed any sub-branch blood vessels positioned along a length of the constricting portion and the at least one second opening includes an opening that provides flow access (a flow path) to the volume around the outer surface.

Optionally, the at least one second opening is a single opening with an outlet diameter that is smaller than a diameter at the inlet. In some example embodiments, the smaller opening at the distal end is configured to be at least partially spaced away from an inner blood vessel wall when the device is implanted therein. Optionally, the second opening is at least partially spaced away from the anchoring element. Spacing between the second opening and the anchoring element provides a backflow path along a length of the device.

Optionally and preferably, the constricting portion tapers from its proximal end towards a neck section and then flares from the neck section to its distal end. Optionally, the neck section is a radial neck section. Optionally, the neck section is off-centered over a length of the device and closer to the distal end than to the proximal end. Optionally, the neck section is at a position corresponding to 50%-90% of the device length from the proximal end. Alternatively, the neck section may be centered over a length of the device. The flaring angle between the neck section and the distal end may or may not correspond to the tapering angle between the proximal end to the neck section. Optionally, a diameter of the constricting portion at the distal end is 2 mm-20 mm less than the diameter of the constricting portion at the proximal end in an implanted state (or in its fully expanded state). Optionally, an inlet diameter of the constriction portion at the proximal end is 25 mm-35 mm, e.g., 30 mm. Alternatively, constricting portion does not include the flaring section between the neck section and the distal end. According to some example embodiments, the proximal end of the constricting portion is configured to abut the inner blood vessel wall and direct the flow therethrough while the distal end is configured to be at least partially spaced away from the inner arterial wall to allow backflow between the constricting portion and the inner wall along a length of the constricting portion.

In some example embodiments, the constricting portion is a cylindrical body including the neck section. Optionally and preferably, the neck section has a diameter that is 5 mm-15 mm. According to some example embodiments, a diameter of the narrowing, e.g. the neck section is configured to be substantially maintained throughout the cardiac cycle and over the period of treatment. Optionally, the narrowing is released (or opened) manually during a catheterization procedure. In some example embodiments, the narrowing is released and/or expanded with a balloon inserted and inflated therein. Release of the narrowing may be actuated to terminate the treatment. Optionally, the device accommodates some variation in neck diameter due to pulsating flow, e.g. 0%-20%. Optionally, and preferably, a selected diameter for the narrowing is supported with a dedicated constricting element that is maintained on the cylindrical body. Optionally, the constricting element is in the form of a ring-shaped element and/or a wire wrapped and secured around the cylindrical body. According to some example embodiments, the constricting element is configured to support the narrowing at the neck section over an extended period of time, e.g. over a plurality of years.

According to some example embodiments, the cylindrical body is a collapsible frame that is configured to expand to a defined shape. Optionally and preferably, the frame is formed from shape memory material. According to some example embodiments, the frame is at least partially lined and/or encapsulated with a cover and the frame together with the cover define the constricting portion of the device. Optionally and preferably, the cover is a liquid impermeable lining (or membrane). Optionally, the cover is a pliable material that may form folds and/or creases when further constricting the neck section with the constricting element. Example materials for the cover include PTFE, polyurethane and silicone. In some example embodiments, the cover may have elastic properties. Optionally, the clastic properties provide reducing or avoiding folds over a range of diameters for the neck section when further constricting the neck section with the constricting element. Optionally, the cover is formed with a polymer material.

As defined herein, the portion of the frame that is lined with the cover defines the constricting portion of the frame that extends between the proximal end and the distal end. Optionally, the cover is applied to the frame while the frame is in its neutral configuration, e.g. fully expanded. In some example embodiments, the neutral configuration includes a neck section, which may be significantly larger in diameter than an operational constriction diameter used for treatment. Optionally, in operation, the neck section is constricted to a smaller diameter (the operational diameter) with the constricting element. The constricting element may be positioned before or after implantation.

According to some example embodiments, the constricting portion is formed with a frame that is partially covered with the cover. Optionally and preferably, the cover is not along the entire length of the frame so that a portion of the frame extending past the distal end of constricting portion is exposed and allows flow therethrough. In some example embodiments, the exposed portion of the frame is configured to flare to a substantially same diameter as the proximal end of the constricting portion in its neutral or fully expanded state. Optionally, the frame is fixed to the anchoring element at one or both ends.

According to some example embodiments, the anchoring element is an outer frame (or second frame) that is configured to substantially surround the constricting portion. According to some example embodiments, the anchoring element is fixedly attached to the proximal end of the constricting portion, the distal end, both the proximal end and the distal end, or anywhere else along the constricting portion. Optionally, when the constricting portion is formed with a frame that is partially lined with a cover, the anchoring element is fixedly attached to one or both ends of the frame. In some example embodiments, the anchoring element is configured to promote tissue ingrowth and/or provide an atraumatic interface while anchoring the device within the inner wall of the blood vessel. Optionally, the outer frame and the inner frame are defined to have the same length. In other example embodiments, the outer frame may be either longer or shorter than the inner frame. Optionally, more than one anchoring element may be used to anchor the device. Optionally, a first anchoring element may be configured to anchor a proximal end of the constricting portion and a second anchoring element may be configured to anchor a distal end of the constricting portion within the arterial inner wall. Optionally, each of the first and second anchoring elements is a collapsible frame.

According to some example embodiments, the device is further fitted with a circumferential sealing strip extending from the proximal end and partially covering, e.g. lining the anchoring element. In some example embodiments, the circumferential sealing strip extends over a length of 2 mm-10 mm or 3 mm-8 mm, e.g. 5 mm or 7.5 mm. In some example embodiments, when the anchoring element is a collapsible frame, the circumferential scaling strip is configured to extend to a first array of strut junctions on the collapsible frame. According to some example embodiments, the circumferential sealing strip is configured to enhance a seal between the proximal end of the constricting portion and the inner wall of the blood vessel. According to some example embodiments, the length of the circumferential sealing strip is selected to provide an adequate seal while reducing a risk of covering sub-branch blood vessels, e.g. sub-branch pulmonary arteries. In some example embodiments, the circumferential scaling strip is configured to be fixed to and/or integrated with the proximal end of the cover lining the inner frame. Optionally and preferably, the circumferential sealing strip is formed with pliable material, e.g. with the same material used for the cover lining of the inner frame, e.g. PTFE, polyurethane or silicone. Optionally, when the device includes more than one anchoring elements, the circumferential sealing strip is configured to line the anchoring element at the proximal end.

Reference is now made toFIGS.1A and1Bshowing simplified schematic drawings of two example devices in accordance with some example embodiments. According to some example embodiments, a device, e.g. device101or device102include a constricting portion130though which flow20in an artery or other blood vessel10is directed and an anchoring element120. Anchoring element120is configured to prevent shifting of constricting portion130along a length of blood vessel10and optionally and preferably to support a defined orientation of constricting portion130within blood vessel10when implanted therein. According to some example embodiments, anchoring element120is a cylindrical structure with substantially constant diameter that corresponds to diameter D of blood vessel10. In some example embodiments, anchoring element120is a frame, e.g. a mesh and/or a stent that is configured to engage and/or abut inner wall11of blood vessel10without blocking flow into a sub-branch artery15along a length of anchoring element120. Optionally and preferably, anchoring element120is collapsible. Optionally and preferably, anchoring element120is configured to self-expand from a collapsed state to an operational state. Optionally and preferably, in an operational state, anchoring element120assumes a diameter D of blood vessel10.

According to some example embodiments, constricting portion130is shaped to taper from a proximal end105to a neck section140having a diameter D2. Optionally and preferably, constricting portion130is fixed to anchoring element120at proximal end105and a diameter D1of constricting portion130at proximal end105may be substantially the same as diameter D of blood vessel10when implanted therein. According to some example embodiments, tapering of constricting portion130defines a space and/or volume18surrounding constricting portion130in which blood flow30′ exiting constricting portion130may flow in an upstream direction40along a length L1to feed sub-branch artery15.

According to some example embodiments, distal end107of constricting portion130is spaced away from anchoring element120and/or inner wall11to create flow access into volume18between constricting portion130and inner wall11. According to some example embodiments, blood flow30exiting flow constricting device120is free to flow downstream and also in an upstream direction40, e.g., flow30′ over a length L1of constricting portion130. Flow30may typically exit the device (e.g., device101or device102) with some turbulence so that while some of flow30flows in a natural downstream direction through blood vessel10, a portion of the flow (flow30′) will flow in space18between constricting portion130and inner wall11of blood vessel10creating backflow30′. Optionally and preferably, the backflow30′ of blood in an upstream direction40(backflow) is blocked at proximal end105. Flow into volume18may provide feeding any sub-branch artery (or arteries)15. Any excess backflow30′ that is not fed into sub-branch arteries15may reverse direction and flow downstream blood vessel10.

Optionally, anchoring element120includes one or more structures to support constricting portion130, neck section140and/or flared section145in a concentric orientation with respect to anchoring element120and/or blood vessel10. In other example embodiments, neck section140may be configured to be non-concentrically oriented with respect to anchoring element120and/or blood vessel10, and anchoring element120supports the tapered structure and/or neck section140in the defined non-concentrically orientation.

According to some example embodiments, the device (device101or device102) is implanted in a pulmonary artery, e.g. a branch pulmonary artery and diameter D2is defined to affect a desired raise in pressure in the right ventricle of the heart upstream from the device (device101or device102).

In some example embodiments as shown inFIG.1A, an example device101including neck section140is at a distal end107of constricting portion130and flow30exiting constricting portion130exits from neck section140. Neck section140is defined to have a diameter D2that is smaller than diameter D1at proximal end105. In some example embodiments, D2is 5 mm-15 mm or 7 mm-10 mm. According to some example embodiments, neck section140is configured to be at least partially spaced away from inner wall11of blood vessel10when implanted therein. According to some example embodiments, neck section140provides flow access to volume18that may otherwise have been blocked based on diverting flow in the artery through constricting portion130. According to some example embodiments, based on the defined geometry of constricting portion130, flow exiting neck section140is free to flow upstream (flow30′) into volume18as well as downstream (flow30) in its natural direction through blood vessel10.

In some example embodiments, length L1is 0 mm-40 mm and D1is 25 mm-35 mm in a neutral state (prior to being implanted within blood vessel10). Optionally and preferably, the device is in a partially compressed state when implanted within blood vessel10so that D1while implanted within blood vessel10may be less than D1prior to being implanted.

In some example embodiments, as shown inFIG.1B, an example device102includes a flared section145in constricting portion130that extends downstream from neck section140to distal end107. According to some example embodiments, flared section145at distal end107has a diameter D3that is larger than diameter D2of neck section140and smaller than diameter D1of constricting portion130at proximal end105while implanted within artery10. According to some example embodiments, D3is defined to be at least 10% smaller than D1. According to some example embodiments, D3is at least 10% smaller than D1at its neutral state (prior to being implanted within blood vessel10). Optionally, D3is 15 mm-27 mm and D1is 28 mm-32 mm at its neutral state (prior to being implanted within blood vessel10).

According to some example embodiments, flared section145is configured to be at least partially spaced away from inner wall11of blood vessel10when implanted therein to provide flow access to volume18that may otherwise have been blocked based on diverting flow in the artery through constricting portion130. According to some example embodiments, flow exiting flared section145is free to flow upstream (flow30′) into volume18as well as downstream (flow30) in its natural direction through blood vessel10.

In some example embodiments, flared section145may flare at an angle46that is wider than an angle44of tapering. In other example embodiments, flaring angle46and tapering angle44may be the same or flaring angle46may be less than tapering angle44.

According to some example embodiments when constricting portion130includes flared section145, neck section140is positioned around a middle of constricting portion130or toward a distal end107. For example, L11may be 40%-90% of L1.

Reference is now made toFIGS.2A and2Bshowing two example devices with a partially covered inner frame forming a narrowing in accordance with some example embodiments. According to some example embodiments, a device, e.g. device103or device104includes anchoring element120and an inner frame135that is partially lined with a cover133. Optionally and preferably, inner frame135is a mesh and/or a stent that is collapsible. Optionally and preferably, inner frame135is configured to self-expand from a collapsed state to an operational state. In some example embodiments inner frame135is formed with a shape memory material and/or shape memory alloy, e.g., Nitinol. Inner frame135may be braided or may be tube that is cut with a meshed pattern.

According to some example embodiments, cover133extends from proximal end105to distal end107. Optionally and preferably, cover133is a liquid impermeable cover or lining. According to some example embodiments, the partial lining of inner frame135with cover133forms constricting portion130. Optionally and preferably, inner frame135includes neck section140. Constricting portion130is defined herein as a portion of inner frame135that is lined with cover133and extends from proximal end105to distal end107. Distal end107may be at neck section140(similar to device101inFIG.1A) or at a defined distance downstream neck section140to define a flared section145. Flared section145may be as described inFIG.1B. According to some example embodiments, distal end107of constricting portion130includes an opening through which flow within constricting portion130may be expelled.

Optionally and preferably, both anchoring element120and inner frame135are collapsible frames. Inner frame135may be positioned within anchoring element120and may be aligned in a same direction as anchoring element120. According to some example embodiments, inner frame135is fixedly attached at least at proximal end105to anchoring element120. In some example embodiments, inner frame135and anchoring element120have a same length L2. In some example embodiments, inner frame135is fixedly attached at both ends to anchoring element120, e.g., at proximal end105and at frame distal end111. Optionally, inner frame135is fixed to anchoring element120at least at each of proximal end105and at frame distal end111.

According to some example embodiments, cover133is formed from a pliable material. Optionally, cover133is PTFE, polyurethane, silicone or a hybrid material, e.g. an electrospun polytetrafluoroethylene/polyurethane (PTFE/PU) composite. Cover133may be sewn, welded, glued or otherwise attached to inner frame135. In some example embodiments, cover133includes an inner cover that lines an inner surface of a portion of inner frame135. Optionally, cover133includes an outer cover that lines an outer surface of a portion of inner frame135. Optionally and preferably, cover133includes both an inner cover and an outer cover, encapsulating inner frame135. Optionally, inner cover and outer cover may be sewn, welded, glued or otherwise connected to form cover133.

According to some example embodiments, the device (device103or device104) is implanted in a pulmonary artery, e.g. a branch pulmonary artery, and diameter D2is defined to affect a desired raise in pressure in the right ventricle of the heart upstream of the device.

Referring now toFIG.2A, in some example embodiments, impermeable cover133extends past neck section140to form a flared section145through which flow30exits from constricting portion130. According to some example embodiments, flow30exiting constricting portion130is free to flow in and out of volume18between constricting portion130and inner wall11, e.g. flow30′. D1, D2, D3and L1may be as described herein, e.g. in reference toFIGS.1A and1B. In some example embodiments, a diameter of inner frame135at frame distal end111may be substantially the same as D1in a neutral state of device103(prior to implanting). In some example embodiments, L2is 28 mm-32 mm, e.g. 30 mm. Optionally, neck section140is positioned anywhere between substantially in a center of inner frame135and 1-5 mm from distal end107.

Referring now toFIG.2B, in some example embodiments, impermeable cover133extends along an entire length L2of device104with one or more openings137through which backflow30′ may flow toward sub-branch artery15. Optionally and preferably, one or more openings137are configured to provide free flow into and out of space18. Constricting portion130in this embodiment is defined as a portion of inner frame135that extends from proximal end105to one or more openings137. D1, D2, D3, L1and L2may be as described herein, e.g. in reference toFIGS.1A,1B and2A. Length L31may be 1 mm-4 mm and/or L31is 10% of L2.

Reference is now made toFIG.3showing the example device with an outer circumferential sealing strip in accordance with some example embodiments. According to some example embodiments, device103includes a circumferential scaling strip150that lines a portion of anchoring element120. Circumferential sealing strip150may be sewn, welded, glued or otherwise attached to anchoring element120. Optionally, circumferential sealing strip150is an integral part of anchoring element120, e.g. a liquid impermeable portion of anchoring element120. In some example embodiments, circumferential sealing strip150includes an inner cover that lines an inner surface of anchoring element120, an outer cover that lines an outer surface of anchoring element120or both an inner cover and an outer cover.

According to some example embodiments, circumferential scaling strip150is configured for improving a sealed engagement of proximal end105of constricting portion130with inner wall11so that flow20within blood vessel10will be directed through constricting portion130and not leak around constricting portion130. According to some example embodiments, circumferential sealing strip150further provides a seal configured to prevent backflow30′ from flowing upstream proximal end105.

In some example embodiments, it is advantageous to limit a length of circumferential scaling strip150to prevent a risk that circumferential sealing strip150may cover, e.g. block entrance into sub-branch artery15extending from blood vessel10in which device103is implanted while being long enough to provide the desired sealing. In some example embodiments, circumferential sealing strip150is defined to have a length L3of 2 mm-10 mm or 3 mm-8 mm, e.g., 5 mm or 7.5 mm.

In some example embodiments, sealing strip150includes or is integrally connected to an annular extension155configured to block flow30′ from entering a pocket space19between circumferential sealing strip150and cover133.

Reference is now made toFIG.4showing the example device with a constricting element, in accordance with some example embodiments. According to some example embodiments, a diameter of neck section140is set with a constricting element148that encompasses and/or is wrapped around constricting portion130. In some example embodiments, constricting element148is configured to narrow neck section140to obtain a desired narrowing, e.g., a desired diameter D2. In some example embodiments, constricting element148is configured to support substantially maintaining the narrowing over pulsating flow through the artery. Optionally, a 0%-20% change in diameter may be expected over the cardiac cycle with constricting element148. Constricting element148may be a Nitinol wire or tube. Optionally, a diameter D2may be defined by fixing ends of constricting element148, e.g. by welding, clasping or fastening. In other example embodiments, constricting element148may be ring piece or a clasp. Optionally, constricting portion130is pre-formed with neck section140and constricting element is configured to further constrict neck section140. In these example embodiments, D2without constricting element148is 15 mm-30 mm and with constricting element148is 5 mm-15 mm. In other example embodiments, is not pre-formed with neck section140. Optionally, a width or shape of constricting element148may be selected to provide a desired geometry for neck section140. In some example embodiments, the further constriction of neck section140with constricting element148introduces ruffles, creases or folds in impermeable cover133. According to some example embodiments, the constricting element148is adjustable and/or openable. Adjusting or opening constricting element148may optionally provide terminating the treatment provided by the device without the need to remove the device from the artery.

Reference is now made toFIGS.5A,5B,5C and5Dshowing images of an example device in different configurations, all in accordance with some example embodiments. According to some example embodiments, flow through an artery may be directed into constricting portion130from proximal end105and exit constricting portion130at distal end107. Optionally, flow exiting distal end107may continue to flow downstream or may flow around an edge131, e.g., a flare of constricting portion130at distal end107and then flow through space18between constricting portion130and anchoring element120in a direction upstream toward proximal end105.

In some example embodiments, circumferential sealing strip150is defined to extend to a first array of strut junctions128formed in anchoring element120. In some example embodiments, favorable scaling is obtained based on extending circumferential sealing strip150to first array of strut junctions128. According to some example embodiments, circumferential scaling strip150and cover133are integral or fixedly connected with a liquid impermeable seal at proximal end105. Optionally, circumferential scaling strip150is an extension of cover133that is folded over anchoring element120.

According to some example embodiments, device103is configured to be implanted in a blood vessel by a trans-catheterization procedure. Optionally, device103includes one or more holding elements180with which device103may be manipulated during the catheterization procedure. Optionally, holding element180are formed on anchoring element120. Optionally, holding element180are positioned near or at proximal end105.

FIG.5Bis an example image of device103in a fully opened state, e.g. maximum radial neck section. Device103is an example device that is pre-formed with neck section140.FIG.5Cis an example image of device103in a further constricted state in which the constriction element148is tightened around the radial neck section.FIG.5Dis an example image of device103in a delivery system. During delivery, e.g., implantation, device103may be collapsed within delivery capsule210. Optionally, device103may be collapsed around a guide wire lumen220extending through a delivery system sheath230.

Reference is now made toFIGS.6A and6Bshowing two drawings of an example inner frame including the constricting portion130shown without and with its cover, both in accordance with some example embodiments. According to some example embodiments, inner frame135is a collapsible frame formed from a shape memory material. Optionally and preferably, inner frame135includes neck section140with a slight narrowing in its neutral state. According to some example embodiments, neck section140may be adjusted, e.g., further constricted with a constricting element that engages neck section140. Optionally and preferably, neck section140in its neutral state is not configured to affect any substantial pressure differential when implanted within a blood vessel. Optionally and preferably, a desired pressure elevation is provided based on further constricting neck section140with the constricting element. In some example embodiments, the slight narrowing in the neutral state predisposes inner frame135to a desired shape, reduces fatigue of material at neck section140that may occur when further constricting with the constricting element and also provides reducing the amount of ruffling of material133that occurs when further constricting with the constricting element.

According to some example embodiments, inner frame135includes an array of weld eyelets124that define each of a proximal end105and a frame distal end111. Optionally, one or more of weld eyelets124are welded or otherwise connected to corresponding weld eyelets on anchoring element120to form device103.

According to some example embodiments, inner frame135is partially lined (or covered) with a cover133that is liquid impermeable. According to some example embodiments, cover133extends from one end of inner frame135, e.g. proximal end105past neck section140to a distal end107that is spaced away from frame distal end111. According to some example embodiments, flow entering through the portion of inner frame135lined with cover133at proximal end105and out from distal end107is free to flow across struts129of a portion of inner frame135extending between distal end107and frame distal end111.

Reference is now made toFIG.7showing a drawing of an example anchoring element shown without a circumferential scaling strip, in accordance with some example embodiments. Optionally and preferably, the anchoring element120is cylindrical in shape and has a constant diameter along its length in its neutral state, e.g. its fully expanded state. Optionally, anchoring element120may vary somewhat in diameter while implanted within a blood vessel based on the mechanical properties of the blood vessel. According to some example embodiments, anchoring element120is a frame, e.g., a mesh including strut elements129joined at strut junctions128.

In some example embodiments, one and/or both ends of anchoring element120is defined by an array of weld eyelets126. Optionally, one or more of these weld eyelets126are configured to be welded or otherwise connected to corresponding weld eyelets124on inner frame135to form device103. Optionally, one or more of weld eyelets126includes holding element180.

According to some example embodiments, openings between strut junctions129allows substantially free blood flow across the frame body. Optionally and preferably, anchoring element120is configured to be collapsible. Optionally and preferably, anchoring element120is made from shape memory material. Optionally, anchoring element120is formed from Nitinol or other shape memory alloy and/or metal material suitable for implanting in blood vessel. Optionally, anchoring element120may be a mesh formed by cutting a tube or by braiding a wire. Optionally, anchoring element120is configured to be self-expanding. Optionally, anchoring element120is configured to be balloon expandable.

Optionally and preferably, circumferential sealing strip150lines a portion of anchoring element120that extends from one end of anchoring element120, preferably from the proximal end. In some example embodiments, circumferential sealing strip150is configured to extend from weld eyelets126and to at least to a first array of strut junctions128. Optionally, one or more of holding elements180may be exposed, e.g. may not be lined with circumferential scaling strip150. In some example embodiments, circumferential sealing strip150extends over a length L3of 2 mm-10 mm or 3 mm-8 mm, e.g., 5 mm or 7.5 mm. In some example embodiments, extending circumferential sealing strip150up to first strut junctions128improves the scaling effect of circumferential scaling strip150and avoids leakage through a flap for fold that may occur in circumferential sealing strip material when not fully stretched between weld eyelets128.

In some example embodiments, inner frame135including the constricting portion130is positioned within anchoring element120and fixed on anchoring element120. Optionally, the fixing includes connecting one or more eyelets124to corresponding eyelets126. In some example embodiments, eyelets124are welded to eyelets126. Inner frame135may be fixed to anchoring element120at proximal end105, at frame distal end111, or both proximal end105and frame distal end111.

Referring back toFIG.5A, according to some example embodiments, circumferential sealing strip150on anchoring element120is connected or fixed to cover133with a seamless connection. Optionally and preferably, circumferential scaling strip150is lined over an outer surface of anchoring element120after fixedly attaching inner frame135to anchoring element120. Circumferential scaling strip150and covering133may be connected to each other or may be integral, e.g., optionally cover133may fold over the proximal edge105and cover the outer surface of the anchoring element120.

Reference is now made toFIGS.8A and8Bshowing two images of a flaring section of an example device from the distal end (flow discharge), shown in an open and constricted configuration respectively, both in accordance with some example embodiments. According to some example embodiments, cover133partially covers inner frame135to form a flow constriction section that tapers to a neck section140and then flares along a flaring section, e.g. flared section145(FIG.1B). In some example embodiments, neck section140is adjustable. Optionally, a diameter of neck section140is defined with a constricting element148(FIG.4) that is positioned around neck section140.

In some example embodiments, cover133is formed from a pliable material. Optionally in an open configuration of flow constricting element130, cover133lines inner frame135with no creases or folds (FIG.8A). Optionally, when constricting neck section140is constricted by constricting element148, creases, ruffles and/or folds may be formed with the cover material of cover133(FIG.8B). In other example embodiments, ruffling is reduced and/or avoided by using a material with enhanced clastic or elastomeric material for cover133.

Reference is now made toFIG.9showing a schematic drawings of example devices implanted in each of the left and right branch pulmonary arteries in accordance with some example embodiments. According to some example embodiments, a device100is implanted in one or more of branch pulmonary arteries10, e.g., left pulmonary artery and right pulmonary artery. Device100generally represents a device configured to form a constriction for flow through blood vessel10and may be any one of devices101,102,103and104. Blood flow20from right ventricle90of heart70flows into main pulmonary artery80and to each of branch arteries10. According to some example embodiments, neck section140constricts flow20and creates back pressure in right ventricle90. Optionally, the back pressure is selected to affect a shift in septum88toward left ventricle95.

According to some example embodiments, one or more of devices100are implanted near a bifurcation85of main pulmonary artery80. Optionally, implanting device100near bifurcation85avoids a risk of diverting flow20into a sub-branch artery15upstream from device100. Such a diversion may potentially lead to excessive flow through such a sub-branch artery15and limit the ability to increase back pressure in the right ventricle90. This excessive flow may be undesirable as it may overload on the sub-branch artery and lead to an uneven distribution of flow in the lung, e.g., one lobe of the lung will receive excessive blood flow and proportionally decrease flow to the other lobes.

According to some example embodiments, device100is configured to allow back flow30′ around device100so that any sub-branch artery15that is covered by device100may have access to flow20from main pulmonary artery80. Neck section140may have a same or different diameter D2in each of branch arteries10. Optionally, a diameter D2of neck section140in each of devices100is defined to maintain a desired split of flow20from main pulmonary artery80into left branch artery and right branch artery. Optionally, one or more features of device100in the right branch artery10may be different than that of device100in left branch artery10. It is noted that anchoring element120as well as other features of device100are not shown here for clarity purposes.

Structural features and details on materials sharing a same reference number can be used with any one of embodiments shown in figures (FIGS.1A-8B). For example, details related to inner frame135discussed in reference toFIG.2Acan also be used in embodiments described in reference toFIGS.3-8B.

As used herein with reference to quantity or value, the term “about” means “within ±10% of”.

The terms “comprises”, “comprising”, “includes”, “including”, “has”, “having” and their conjugates mean “including but not limited to”.

The term “consisting of” means “including and limited to”.

As used herein, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof.

Throughout this application, embodiments of this invention may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

Whenever a numerical range is indicated herein (for example “10-15”, “10 to 15”, or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases “range/ranging/ranges between” a first indicate number and a second indicate number and “range/ranging/ranges from” a first indicate number “to”, “up to”, “until” or “through” (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers therebetween.

Unless otherwise indicated, numbers used herein and any number ranges based thereon are approximations within the accuracy of reasonable measurement and rounding errors as understood by persons skilled in the art.