Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION: PROSTHETIC HEART VALVE
2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company of the address Survey No. 135/139, Bilakhia House Muktanand Marg, Chala, Vapi, Gujarat 396191, India

The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
[001] The present disclosure relates to a prosthetic heart valve. More specifically, the present invention relates to a prosthetic heart valve to be implanted percutaneously.
BACKGROUND OF INVENTION
[002] The human heart is a hollow organ with four chambers separated by respective valves (the aortic, pulmonary, tricuspid and mitral valves). The valves of the human heart can suffer from various diseases which result in malfunctioning of the heart causing serious cardiovascular compromise or death. The diseased heart valve may be stenotic and/or incompetent. A stenotic valve is not able to open sufficiently to allow adequate blood flow through it. An incompetent valve is not able to close completely causing blood to flow backwards in quantities more than that in a normally functioning valve.
[003] Recently, a percutaneous catheterization technique has been developed for introducing and implanting a prosthetic heart valve using a flexible catheter. In this technique, a prosthetic valve is mounted by crimping at the distal end of a flexible catheter. The catheter is introduced into a blood vessel (such as a femoral or carotid artery) of the patient and advanced through the blood vessel till the crimped valve reaches the implantation site. The valve is allowed to expand to its functional size at the site of the defective native valve.
[004] Despite the availability of advanced catheterization techniques, more often than not, the interventionalist cardiologist finds it difficult to accurately place and implant the prosthetic heart valve at the native valve annulus. As the implantation procedure is mostly dependent on the visibility of the prosthetic heart valve via fluoroscopy techniques, poor visibility of the prosthetic heart valve during the implantation procedure makes it hard for the interventionalist cardiologists to ascertain the position of the prosthetic heart valve with respect to the native heart valve annulus.
[005] Thus, there is a need for a prosthetic heart valve that provides excellent visibility under fluoroscopy so as to enable the interventionalist cardiologists to accurately place and implant the prosthetic heart valve at the native valve annulus.
SUMMARY OF INVENTION
[006] The present disclosure discloses a prosthetic valve including a support frame having a distal end, a proximal end and three adjacently placed rows of hexagonal cells between the distal end and the proximal end. The three rows include an upper row, a middle row and a lower row. The lower row is placed towards the distal end of the support frame. The support frame includes an expanded condition and a crimped condition. Each hexagonal cell has a plurality of straight strut members, and a plurality of V-shaped strut members having two arms. The upper row occupies 50-55% of total length of the support frame. In the crimped condition, high density areas corresponding to the V-shaped strut members alternate with low density areas corresponding to straight strut members are formed along the length of the support frame.
[007] The foregoing and other features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[008] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended figures. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the figures. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those familiar with the art will understand that the figures are not to scale. Wherever possible, like elements have been indicated by identical numbers.
[009] In the figures and the description to follow, the terms “frame” or “stent” or “frame structure” or “scaffold structure” or “support frame” or “scaffold” refer to the metallic frame of this invention. These terms are used interchangeably but carry the same meaning. The term “valve” or “prosthetic valve” refer to the prosthetic valve of this invention assembled using the frame structure and other components like leaflets of animal tissue, skirt, etc. These terms are also used interchangeably. The term “native valve” is used for the natural valve in human heart.
[0010] FIG. 1 is a perspective view of the support frame in accordance with an embodiment of the present disclosure.
[0011] FIG. 1A is the front view of the support frame of FIG. 1 in accordance with an embodiment of the present disclosure.
[0012] FIG. 1B depicts a prosthetic valve in accordance with an embodiment of the present disclosure.
[0013] FIG. 2 is a partial view of the cells of the support frame of FIG. 1 and 1A when the cylindrical frame is cut vertically across its length L and flattened on a plane surface in accordance with an embodiment of the present disclosure.
[0014] FIG. 3 is a schematic view of the prosthetic valve of FIG. 1B when crimped on the balloon of the delivery system in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION OF ACCOMPANYING DRAWINGS
[0015] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise.
[0016] The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[0017] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[0018] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and appended claims, or may be learned by the practice of embodiments as set forth hereinafter.
[0019] Disclosed embodiments of an improved radially expandable and compressible support frame having a plurality of leaflets made of animal tissue can be used with any prosthetic valve, such as a prosthetic aortic heart valve. The prosthetic valve with the embodiments of the support frame offers many advantages as described further.
[0020] The terms “upper”, “middle”, “lower”, “vertical” and “horizontal” refer to a specific way an item or a component is shown in a diagram and do not refer to absolute direction or location.
[0021] The present invention discloses a balloon expandable prosthetic heart valve (or prosthetic valve) implanted by catheterization technique in a human stenosed aortic orifice.
[0022] A representative embodiment of the present disclosure provides a prosthetic valve having a flexible support frame which can expand and collapse, a plurality of leaflets (preferentially three leaflets) formed from animal tissue and an annular skirt made from a fabric attached to the frame. Each leaflet has a rectangular shape portion at one end followed by a semi-circular arc (scallop shape) at the other end and two attachment nodes for attaching the leaflet to commissure posts. The scallop shaped portion is fixed by suturing to lower part of the frame and the skirt.
[0023] The design of the support frame helps an operator in precisely positioning and deploying the prosthetic valve by viewing under fluoroscopy during implantation procedure. Moreover, the support frame length is such that the protrusion of the support frame in LVOT after precise implantation is limited to maximum 4 mm, preferably around 3.3 – 3.5 mm. This eliminates any possibility of disturbance of the cardiac muscles which carry electrical signals and interfering with normal functioning of the anterior leaflet of the mitral valve. The total length of the support frame is such that the portion of the support frame extending into the ascending aorta after precise implantation and the large open cells in the upper row of the support frame ensure un-jailing of the coronary ostia. The design of the support frame makes the prosthetic valve mechanically stronger to make it possible to reduce the strut thickness to 350 micrometers without compromising mechanical strength (radial strength and fatigue resistance) of the support frame.
[0024] FIGs. 1 and 1A are embodiments of a support frame 110 of an exemplary embodiment of the prosthetic valve. FIG. 1 is perspective view of the support frame 110 and FIG. 1A depicts front view of the support frame 110 of FIG. 1 when viewed from direction A. As depicted, the support frame 110 is a cylindrical scaffold structure with diameter D and length L. The support frame 110 has a distal end 117 and a proximal end 118. Further, there are three rows, upper row 111, middle row 112 and lower row 113 of hexagonal cells disposed between the distal and proximal ends 117, 118. The hexagonal cells located in a single row have same cross-sectional area, e.g. cross-sectional area of hexagonal cells located in upper row 111 is same. However, the cross-sectional area of hexagonal cells located in different rows may be same or different, e.g. cross-sectional area of cells in upper row 111 may be same or different than the hexagonal cells located in middle row 112 or lower row 113. In an embodiment, the area of hexagon cells of a row is different than the area of hexagonal cells of one or more of the remaining rows.
[0025] The support frame 110 may include a plurality of commissure posts 114 which function to attach one or more leaflets to the support frame 110. As shown in FIG. 1A, there are three commissure posts 114 disposed at 120o with respect to each other located on the upper row 111.
[0026] FIG. 1B depicts the prosthetic valve 110A constructed using the support frame 110 of FIG. 1-1A with diameter D and length L. As depicted in FIG. 1B, there are three commissure posts 114 in the upper row 111 located at 120° to each other. To each of the commissure posts 114, an attachment node of corresponding leaflet is attached. The attachment nodes of two leaflets are sutured to a commissure post 114 of the support frame 110. The scallop portion 115 of the leaflets is attached to the middle row 112 and the lower row 113 by suturing to the cell struts and the skirt 116. Further, a skirt 116 is attached to the support frame 110 covering the middle row 112 and the lower row 113.
[0027] The blood enters from the distal end 117 (inflow/lower end) of the prosthetic valve 110A and is discharged through proximal end 118 (outflow/upper end). Hence, after implantation of the prosthetic valve 110A, the lower end 117 is towards the left ventricle and upper end 118 is towards the ascending aorta.
[0028] FIG. 2 depicts an elemental view of a portion of the support frame 110 of FIG. 1-1A when the cylindrical portion of the support frame 110 is cut vertically along its length L (across X-X shown in FIG. 1A) and flattened. This elemental support frame corresponds to a portion of support frame 110 and is depicted as 210 in FIG 2. The support frame 210 comprises a plurality of repetitive strut members a, b, b1, b2, c and d interconnected to each other to form a scaffold of hexagonal cells. The hexagonal cells are interconnected to yield a honeycomb shaped support frame 110 (FIG. 1-1A). In an embodiment, the support frame 110 has three rows of hexagonal cells viz. upper row 111, middle row 112 and lower row 113 comprising of hexagonal cells 211A, 211B, and 211C respectively.
[0029] The support frame 210 has two ends viz. 212 and 213. The prosthetic valve 110A is structured and implanted in such a manner that the blood flows in through the end 212 and it flows out from end 213. Thus, the end 212 of the support frame 210 is the “inflow end” (corresponding to distal end 117 in FIG. 1/1A/1B) and the end 213 is the “outflow end” (corresponding to proximal end 118 in FIG. 1/1A/1B). After the prosthetic valve 110A is implanted across the native aortic annulus, the blood will enter the prosthetic valve 110A from the end 212 and will leave the prosthetic valve 110A from the end 213. Hence, the end 212 will be towards the left ventricle and the end 213 will be towards the ascending aorta.
[0030] Each hexagonal cell 211A, 211B or 211C, as depicted in FIG. 2, has six sides which correspond to the six strut members a, b, b1, b2, c and d. The said sides of hexagonal cell 211A, 211B or 211C are commonly shared with sides of an adjacent hexagonal cell 211A, 211B or 211C. As shown in FIG. 2, a strut member ‘a’ of each hexagonal cell 211A, 211B or 211C contains two arms at an angle A that form a V-shape. The angle A between the two arms of the V shaped strut member ‘a’ in each hexagonal cell 211A, 211B or 211C may be 120° to 135° (preferably 125° to 130°) when the support frame 110/210 is in its fully expanded state. The angle A between the two arms of the V shaped strut members ‘a’ may be different for different sizes (diameters) of the prosthetic valves 110A.
[0031] The strut members b, b1, b2, c and d of the hexagonal cells 211A, 211B or 211C are straight strut members and connect the two pairs of V shaped strut members ‘a’. In an embodiment, the lengths of straight strut members b, b1 and b2 are same. The lengths of straight strut members c and d may be same or different. In an embodiment, the straight strut members b, b1 and b2 are longer than straight strut members c and d. These features make the cross-sectional area of the hexagonal cells 211A larger than that of the hexagonal cells 211B and 211C. A thickness of the plurality of straight strut members b, b1, b2, c, d and the plurality of V-shaped strut members ‘a’ is 350 micrometers.
[0032] Although the strut members b, b1, b2, c, d are described as straight strut members, they may be replaced with one or more crooked strut members, angled strut members, curvaceous strut members, etc. The same is within the scope of the teachings of the present disclosure.
[0033] In an embodiment, the hexagonal cells 211A of the upper row 111 have strut members ‘a’ and ‘b’. The structure of hexagonal cell 211A has two pairs of V-shaped strut members ‘a’ and two straight strut members ‘b’. The hexagonal cells 211A interconnect with each other to form upper row 111 of hexagonal cells 211A. Two adjacently placed cells 211A share a common straight strut member ‘b’. Each straight strut member acting as a commissure post 215 is composed of straight strut members b1 and b2 in place of a single straight strut member ‘b’.
[0034] The straight strut members b1 and b2 form a rectangular opening of the commissure post 215 in upper row 111 where the attachment nodes of the leaflets are fixed. In an embodiment, there are three pairs of such straight strut members b1/b2 in the support frame 110 located at 120° to each other forming three commissure posts 215. Each commissure post 215 has a rectangular opening formed by straight strut members b1 and b2. There are methods known in art for attaching the leaflets to such commissure posts 215.
[0035] Similarly, in an embodiment, the hexagonal cells 211B of the middle row 112 have strut members ‘a’ and ‘c’. The structure of hexagonal cell 211B has two pairs of V-shaped strut members ‘a’ and two straight strut members ‘c’. The hexagonal cells 211B interconnect with each other to form middle row 112. Two adjacently placed hexagonal cells 211B share a common straight strut member ‘c’.
[0036] Likewise, the hexagonal cells 211C of the lower row 113 have strut members ‘a’ and ‘d’. The structure of hexagonal cell 211C has two pairs of V-shaped strut members ‘a’ and two straight strut members ‘d’. The hexagonal cells 211C interconnect with each other to form lower row 113. Two adjacently placed hexagonal cells 211C share a common straight strut member ‘d’.
[0037] The interconnection points of all the strut members a, b, b1, b2, c and d are rounded. In an embodiment, for example, two V-shaped strut members ‘a’ intersect with each other forming a U shape, shown as “e” in FIG. 2. As is evident in FIG 2, all points of interconnections are rounded in U shape. This U shape helps to dissipate the excessive stress concentration at these intersection points.
[0038] The total length of the support frame 110 of this embodiment is L. In an embodiment, the upper row 111 made of hexagonal cells 211A occupies around 50%-55%, preferably 52%-53% of the total length L of the support frame 110. The middle row 112 and lower row 113 made of hexagonal cells 211B and 211C together occupy the rest of the length of the support frame 110. Due to this, the cross-sectional area of the hexagonal cells 211A is larger than that of the hexagonal cells 211B or 211C.
[0039] The honeycomb structure of support frame 110 makes the frame structure mechanically stronger which makes it possible to reduce the strut thickness without compromising mechanical strength of the support frame 110 viz. its radial strength and fatigue resistance. The low strut thickness results in reduction of the profile of the prosthetic valve 110A when crimped on the balloon of the delivery catheter. The low profile makes it easy to maneuver the crimped prosthetic valve 110A through patient’s vasculature to the target site in aorta. In an embodiment, the support frame 110 is made from a metal alloy, say, Cobalt-Chromium-Molybdenum alloys, for example, MP35N or alloy L605. The thickness of the strut members of the support frame 110 of an embodiment, when made from alloy MP35N, is 350 micrometers. The support frame 110 has radial strength of at least 100 Newtons, preferably in the range of 150-200 Newtons. This support frame 110 successfully passed durability test for 600 million cycles under conditions specified in ISO 5840.
[0040] As shown in Fig. 2, the hexagonal cells 211B and 211C are located in the lower half of the support frame 210, i.e., towards the inflow end 212 of the prosthetic valve 110A (upstream of the blood flow) and are located towards the left ventricle. The inflow end 212 of the prosthetic valve 110A experiences higher mechanical forces than the outflow end 213 of the prosthetic valve 110A. In an embodiment, the hexagonal cells 211B and 211C have lower cross sectional area than the hexagonal cells 211A. This results into more dense structure of the hexagonal cells 211B and 211C than the hexagonal cells 211A which imparts higher radial strength to the lower portion of the prosthetic valve 110A to withstand higher mechanical forces at the inflow end 212.
[0041] In an embodiment of the present invention, when the prosthetic valve 110A is implanted precisely, the protrusion of the prosthetic valve 110A in LVOT is limited to maximum 4 mm, preferably around 3.3 – 3.5 mm. This eliminates any possibility of disturbance of the cardiac muscles which carry electrical signals and interfering with normal functioning of the anterior leaflet of the mitral valve.
[0042] The overall length L of the prosthetic valve 110A is low and varies from 17 mm to 29 mm (for prosthetic valve 110A with diameter D varying from 20 mm to 32 mm) when the support frame 110 (and the prosthetic valve 110A) is in its expanded condition. Lower length of the prosthetic valve 110A helps in eliminating jailing of coronary ostia.
[0043] When the support frame 110 (and the prosthetic valve 110A) is collapsed from its expanded condition to its crimped condition, the length L of the prosthetic valve 110A increases and the diameter D decreases. In an exemplary embodiment, the length L of the prosthetic valve 110A, in its crimped condition, increases in a range of 21% to 24%. In another exemplary embodiment, the length L of the prosthetic valve 110A, in its crimped condition, increases in a range of 18% to 22%. In an exemplary embodiment, the diameter D of the prosthetic valve 110A, in its crimped condition, decreases from 20 mm to 7 mm (for the prosthetic valve 110A having a nominal volume diameter of 20mm), i.e., by more than 2.8 times. In another exemplary embodiment, the diameter D of the prosthetic valve 110A, in its crimped condition, decreases from 32 mm to 7.8 mm (for the prosthetic valve 110A having a nominal volume diameter of 32mm), i.e., by more than 4.1 times.
[0044] On precise implantation of the prosthetic valve 110A, the hexagonal cells 211A would be positioned generally above the native valve i.e., where the coronary ostia are located. As stated above, the length L of the support frame 110 is low which ensures that the prosthetic valve 110A does not jail the coronary ostia. In addition, the hexagonal cells 211A have higher cross sectional area i.e. higher open area (hatched area 214 in FIG. 2). This further ensures that there is no obstruction to the blood flow to the coronary ostia.
[0045] It is important that the prosthetic valve 110A is implanted precisely at an optimal location to ensure optimal performance. Ideally, the location of the leaflets (cusps) of a prosthetic valve 110A should be located where the cusps of the native valve are located. This is generally achieved by the operator’s judgment during implantation under fluoroscopic imaging. The structure of the support frame 110 of the prosthetic valve 110A of the present invention guides the operator to position the prosthetic valve 110A precisely during implantation (as explained below).
[0046] The prosthetic valve 110A is meant to be mounted on a delivery system catheter by crimping it over the balloon of the delivery catheter.
[0047] FIG. 3 illustrates schematically the prosthetic valve 311 after crimping on the balloon 312 of the delivery system.
[0048] In an embodiment, the crimped prosthetic valve 311 exhibits alternate “dark bands” and “light bands” as visualized under fluoroscopy. The number of “dark bands” and “light bands” exhibited by the prosthetic valve 311 depends on the number of rows of hexagonal cells 211A, 211B and 211C present in the support frame 110 of the prosthetic valve 311.
[0049] In an exemplary embodiment, as shown in Fig. 3, the support frame 110 having three rows of hexagonal cells 211A, 211B and 211C, the support frame 110 will exhibit four “dark bands” and three “light bands”. The zone visible near the distal balloon marker 313 is the first dark band 316. The order of zones is: first dark band 316- first light band 317- second dark band 318- second light band 319- third dark band 320- third light band 321-fourth dark band 322. As seen in the FIG. 3, the distal and proximal balloon markers 313 and 314 lie outside the length of the crimped prosthetic valve 311 (i.e., beyond the first dark band 316 and the fourth dark band 322).
[0050] When the support frame 110 is crimped to its crimped state (or crimped condition), the angle A between the two arms of the V-shaped strut member ‘a’ reduces to angle B (not shown). One or more high density areas are formed due to said reduction of angle A to angle B. The arms of the V-shaped strut member ‘a’ comes close (or aggregate) to each other, thereby increasing the density of the material of the support frame 110 where the V-shaped strut members ‘a’ are disposed, thereby forming high density areas. The said aggregation of the V-shaped strut members ‘a’ when the support frame 110 is crimped and the resultant high density of the material of the support frame 110 is observed as “dark bands” under fluoroscopy.
[0051] Due to the aggregation of the arms of the V-shaped strut members ‘a’, each of the straight strut members b, b1, b2, c and d comes close to an adjacent straight strut members b, b1, b2, c and d when the support frame 110 is crimped to its crimped state (or crimped condition).
[0052] After the support frame 110 is crimped to its crimped state, one or more low density (of material) areas are formed by the straight strut members b, b1, b2, c, d. The straight strut members b, b1, b2, c, d aggregate together to increase the density of the material of the support frame 110. However, due to the presence of relatively less number of straight strut members ‘b’, ‘c and ‘d’ (because, each of the straight strut members ‘b’, ‘c’ and ‘d’ are shared by adjacent hexagonal cells 211A, 211B and 211C respectively), the increase in density of the material of the support frame 110 due to the straight strut members ‘b’, ‘c’ and ‘d’ is relatively less than the increase in density of the material of the support frame 110 due to the V-shaped strut members ‘a’. Thus, the V-shaped strut members ‘a’ produce one or more high density (of material) areas of support frame 110 and the straight strut members b, b1, b2, c, d produce one or more low density (of material) areas of support frame 110.
[0053] Accordingly, under fluoroscopy, the “light bands” are formed as a result of lower density of material of the support frame 110 due to the aggregation of the straight strut members b, b1, b2, c and d.
[0054] Moreover, the material used for the construction of support frame 110 aids in the visualization of dark bands and light bands. When the crimped prosthetic valve 311 is viewed under fluoroscopy, the V-shaped strut members ‘a’ at the lowest end (marked as 1 in FIG. 2) are visible as the first dark band 316 (FIG. 3). The straight strut members in lower row 113, marked as 2 in FIG. 2 are visible as first light band 317 in FIG. 3. In similar manner V-shaped strut members ‘a’ marked as 3 (FIG. 2) are visible as second dark band 318 in FIG. 3. In this way the strut members marked 4, 5, 6 and 7 are visible as second light band 319, third dark band 320, third light band 321 and fourth dark band 322 respectively. In an embodiment of the present invention, the support frame 110 is constructed of Cobalt-Chromium-Molybdenum alloy such as MP35N or alloy L605.
[0055] The exemplary embodiment of the prosthetic valve 110A, 311 described above has a support frame 110, 210 having three rows of hexagonal cells 211A, 211B or 211C. The prosthetic valve 110A, 311 may be precisely placed under fluoroscopy by locating a light/dark band using aortic annular aorta as reference.
[0056] Similarly, the said teaching may be applied to the frame of a prosthetic valve having more than three rows of cells. For example, a frame with four rows of hexagonal cells will exhibit five dark bands and four light bands. Similarly, a frame with five rows of hexagonal cells will exhibit six dark bands and five light bands. In either case, precise positioning of the crimped valve may be achieved by locating a particular light band or a particular dark band with respect to aortic annular plane using the aortic annular plane as reference. In an individual case, the aortic annular plane may align with an edge of a band or may bisect a band depending on number of rows and dimensions of individual rows in a frame. A person skilled in art can work out the number and dimensions of the cells and fix the criteria for precisely locating the valve with respect to the anatomical features of the native valve annulus using same principles for any frame structure.
[0057] The teaching of this invention may also be applied to a prosthetic valve frame made of cells that are not hexagonal, provided, this frame structure should exhibit alternate light bands and dark bands under fluoroscopy when the valve is positioned in human aortic orifice.
[0058] In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims.
[0059] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , C , C , C , Claims:WE CLAIM
1. A prosthetic valve (110A, 311) comprising:
a support frame (110, 210) having a distal end (117), a proximal end (118) and three adjacently placed rows of hexagonal cells (211A, 211B or 211C) between the distal end (117) and the proximal end (118), the three rows comprise an upper row (111), a middle row (112) and a lower row (113) where the lower row (113) is placed towards the distal end (117) of the support frame (110, 210), the support frame (110, 210) having an expanded condition and a crimped condition;
wherein, each hexagonal cell (211A, 211B or 211C) has
a plurality of straight strut members (b, b1, b2, c, d), and
a plurality of V-shaped strut members (a) having two arms;
wherein, the upper row (111) occupies 50-55% of total length (L) of the support frame (110, 210);
wherein, in the crimped condition, high density areas corresponding to the V-shaped strut members (a) alternate with low density areas corresponding to straight strut members (b, b1, b2, c, d) are formed along the length (L) of the support frame (110, 210).
2. The prosthetic valve (110A, 311) as claimed in claim 1, wherein cross-sectional area of the hexagonal cells (211A) of the upper row (111) is different than the cross-sectional areas of the hexagonal cells (211B, 211C) of the middle or lower row (112, 113).
3. The prosthetic valve (110A, 311) as claimed in claim 1, wherein an angle A between the two arms of the V shaped strut member (a) in each hexagonal cell (211A, 211B, 211C) ranges from 120° to 135°.
4. The prosthetic valve (110A, 311) as claimed in claim 1, wherein the length (L) of the support frame (110, 210) varies between 17 mm and 29mm.
5. The prosthetic valve (110A, 311) as claimed in claim 1, wherein a diameter (D) of the support frame (110, 210) varies between 20 mm to 32 mm.
6. The prosthetic valve (110A, 311) as claimed in claim 1, wherein a thickness of the plurality of straight strut members (b, b1, b2, c, d) and the plurality of V-shaped strut members (a) is 350 micrometers.
7. The prosthetic valve (110A, 311) as claimed in claim 1, wherein the support frame (110, 210) is made of Cobalt-Chromium-Molybdenum alloys.
8. The prosthetic valve (110A, 311) as claimed in claim 1, wherein the support frame (110, 210) includes a plurality of commissure posts (114) to attach one or more leaflets to the support frame (110, 210).
9. The prosthetic valve (110A, 311) as claimed in claim 1, wherein a skirt (116) is attached to the support frame (110, 210) covering the middle row (112) and the lower row (113).
10. The prosthetic valve (110A, 311) as claimed in claim 1, wherein the length (L) of the support frame (110, 210) increases and a diameter D of the support frame (110, 210) decreases when the support frame (110, 210) is collapsed from its expanded condition to its crimped condition.