The description relates to valvular prostheses.
One or more embodiments may apply to valvular prostheses, such as valvular heart prostheses.
Valvular prostheses are an effective means of treating various pathologies, such as e.g. cardiac valve pathologies, and providing a higher life expectancy and less morbidity in those patients receiving an implanted prosthesis.
An increasing demand thus exists for valvular prostheses which may be produced with a cost-effective manufacturing process.
An object of one or more embodiments is to meet such a demand.
One or more embodiments may relate to a corresponding prosthetic valvular device, including e.g. a valvular sleeve coupled with a stent.
The claims are an integral part of the disclosure of embodiments as provided herein.
One or more embodiments will now be described, by way of example only, with reference to the annexed figures, in which:
a to 20d are exemplary of the possible use of pad members in the leaflets of a valvular sleeve of one or more embodiments;
It will be appreciated that, for the sake of clarity, one or more of the figures may not be drawn to a same scale.
In the ensuing description, one or more specific details are illustrated, aimed at providing an in-depth understanding of examples of embodiments. The embodiments may be obtained without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials, or operations are not illustrated or described in detail so that certain aspects of embodiments will not be obscured.
Reference to “an embodiment” or “one embodiment” in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is comprised in at least one embodiment. Hence, phrases such as “in an embodiment” or “in one embodiment” that may be present in one or more points of the present description do not necessarily refer to one and the same embodiment. Moreover, particular conformations, structures, or characteristics may be combined in any adequate way in one or more embodiments.
The references used herein are provided merely for convenience and hence do not define the scope of protection or the scope of the embodiments.
In the figures, reference numeral 10 indicates a valvular prosthesis.
In one or more embodiments, the prosthesis may be adapted for implantation at a valvular site of a patient. A heart annulus, such as e.g. an aortic annulus, may be exemplary of such an implantation site. A pulmonary valvular annulus may be exemplary of another site for implantation of a valvular heart prosthesis. A mitral valvular annulus may be exemplary of a further site for implantation of such an implantation site.
The embodiments are not limited to possible use as a heart valvular prosthesis. Other exemplary implantation sites may include, e.g. various sites in the blood circulatory system, both arterial and venous.
In one or more embodiments, the prosthesis 10 may include a valvular sleeve 14.
In one or more embodiments, the valvular sleeve 14 may include a tubular body intended to define a flow conduit (e.g. a conduit for the flow of blood) between an inflow end IF and an outflow end OF.
In one or more embodiments, the valvular sleeve 14 may include one or more (e.g., a plurality) a plurality of valve leaflets. For example, an embodiment having three leaflets, indicated as 14a, 14b and 14c, are shown by way of example in the drawings. The one or more valve leaflets 14a, 14b, 14c may extend from the inflow end IF towards the outflow end OF (that is distally of the inflow end IF) and is displaceable under fluid pressure, e.g. blood pressure:
It will be appreciated that the designations “inflow end” and “outflow end” refer to the direction of unimpeded fluid flow through the valve prosthesis 10.
In one or more embodiments, the valvular sleeve 14 may be coupled with a supporting armature 16, currently referred to as “stent”, which is intended to support the (generally flexible) valvular sleeve 14.
Stents 16 as exemplified in
Stent configurations may vary depending on the material of the stent. It will be appreciated that a wide variety of biocompatible materials may be incorporated into stents 16.
For instance,
The open (e.g. apertured) configuration of
One or more embodiments may include network-like stent structures, e.g. for valvular prostheses intended to be (e.g. radially) collapsed in view of implantation: EP-A-1 690 515 A1 is exemplary of a valvular prosthesis including such a collapsible stent.
In one or more embodiments, coupling a valvular sleeve 14 with a stent 16 may be either with the stent 16 surrounding (e.g., radially outside of) the valvular sleeve 14 as schematically represented in
In one or more embodiments, the stent 16 may include a ring-like body 160 intended to be located at the inflow end IF of the valvular sleeve 14 and a plurality of posts or prongs 162 extending from the base body 160 in a distal direction from the inflow end IF towards the outflow end OF of the valvular sleeve 14.
In the exemplary configurations of
In one or more embodiments, the leaflets 14a, 14b, 14c of the valvular sleeve 14 may have a semi-lunar (half-moon), scoop-like shape so that each leaflet 14a, 14b, 14c in turn includes a proximal, crescent-shaped margin essentially co-extensive with one of the scallops of the stent 16 as well as a distal margin adapted to coapt with the distal margins of the other leaflets when the valvular sleeve is in the “closed” condition, which impedes fluid flow from the outflow end OF towards the inflow end IF.
In one or more embodiments (e.g. in so-called “stentless” valvular prostheses) a stent 16 may not be present, thus providing a valvular prosthesis of high flexibility.
In one or more embodiments, a valvular prosthesis may include various other elements in addition to the valvular sleeve 14 or the prosthetic valvular device (valvular sleeve 14 plus stent 16) as considered herein.
These other elements may include e.g. a sewing ring R (as exemplified in phantom lines in
The concepts and principles outlined in the foregoing are generally known in the art, thus making it unnecessary to provide a more detailed description herein.
One or more embodiments may take advantage of the possibility of producing the valvular sleeve 14 of a flexible material which may be in the form of e.g. a planar sheet member or a tubular member as better detailed in the following.
Materials adapted to provide a desired degree of flexibility of the valvular sleeve 14 may include e.g.
One or more embodiments may employ sheet or laminar material reinforced by fibers, such as e.g. carbon fibers or Kevlar® fibers.
Materials adapted for use in one or more embodiments may include e.g.:
Materials produced by “tissue-engineering” technologies may represent an option for one or more embodiments.
In one or more embodiments, the valvular sleeve 14 may be coated with a biocompatible coating e.g. a carbonaceous biocompatible coating. Such a coating may extend over the whole sleeve or only over part of it e.g. the part exposed to blood flow.
In one or more embodiments, as exemplified in
Tubular sheet members T as schematically represented in
As exemplified in
An essentially identical result may be obtained with the second section T20 overturned inwardly of the first section T10, so that the section T10 will surround the section T20, with the portions T10, T20 forming then the outer portion and the inner portion, respectively, of the double-walled tubular body of
In one or more embodiments, the overturning process of
In one or more embodiments, the two sections T10, T20, i.e. the inner and outer portions of the tubular body of
In one or more embodiments as exemplified in
Such a U-shaped sheet member as shown in
The end edges L10, L20 may then be joined to each other (e.g. via stitching, adhesive, welding, including ultrasound welding) along a joining line W to again produce a double-walled tubular body as shown in
Whether the portion S10 or the portion S20 will constitute the inner or the outer portion of the tubular body of
In one or more embodiments, joining the opposed end edges L10, L20 of the U-folded sheet member of
In one or more embodiments, the process as described (however performed, i.e. irrespective of the direction of shaping into a ring or collar of
Again, in one or more embodiments the two portions S10, S20, i.e. the inner and outer portions of the tubular body of
In one or more embodiments, such a valvular sleeve 14 for valvular prostheses may include a tubular body (e.g. as shown in
In one or more embodiments:
Whatever the specific arrangement, a tubular body as per
In that way (see e.g.
Due to the inner and outer portions 141, 142 being formed by overturning/folding a sheet-like member (possibly formed into a tube) the inner portion 141 and outer portion 142 will be formed out of a single sheet member having a loop or fold extending around the outflow end OF between the inner and outer portions 141, 142. The inner and outer portions 141, 142 are parts of a same laminar (sheet-like) body e.g. of a fabric material or the like, with a loop or fold at the overturning line T2/folding line S2 located at (e.g. extending around) the outflow end OF of the sleeve 14.
In one or more embodiments, by using a single sheet of material overturned or folded upon itself, the inner and outer portions 141, 142 will not require to be joined at the outflow end OF of the sleeve 14 by resorting to e.g. stitching, gluing, welding and so on, as required if two separate sheets were joined at the outflow end OF of the sleeve 14.
In one or more embodiments, the two portions 141, 142 being already connected at the overturning line T1 or the folding line S2 “originally”, e.g. due to being formed as one piece of fabric or other laminar material, will avoid any sort of cutting (followed by stitching, gluing, welding and so on) as possibly needed to connect two separate portions 141 and 142. In one or more embodiments, the drawbacks possibly related e.g. to fibres of a fabric cut becoming loose, sharp edges or protrusions formed by cutting, stitching, gluing, welding may thus be avoided.
In one or more embodiments the valvular sleeve 14 may be vested onto the stent 16 as schematically shown in
In that way, the valvular sleeve 14 may be retained onto the stent 16 against any force urging the valvular sleeve 14 in the proximal direction (outflow to inflow, e.g. downward in
As noted previously e.g. in connection with
Various types of coupling of the valvular sleeve 14 to the stent 16 may be otherwise envisaged e.g. as exemplified in the following.
Also, while possible coupling of the valvular sleeve 14 to a stent 16 to form a prosthetic valvular device has been exemplified here, the valvular sleeve 14 may be included in a “stentless” valvular prosthesis without being coupled to a stent.
Also, coupling with a stent 16 has been exemplified in
Whatever the embodiments (e.g. a “stentless” arrangement or a “stented” arrangement involving coupling with a stent 16, with the stent 16 arranged inside, outside or inserted between the inner and outer portions 141, 142 of the valvular sleeve 14), the (double-walled) leaflet portions 14a, 14b, 14c may be shaped to a desired semi-lunar (e.g. eyelid-shaped) scoop-like form as exemplified e.g. in
Such shaping of the leaflets may be by known means including e.g. mechanical shaping, liquid pressure, application of heat or combinations of these. The nature of the sheet material (e.g. fabric or tissue) of the valvular sleeve 14 may dictate or limit available options for the technique(s) adopted for shaping the leaflets.
In that way, the inner and outer portions 141, 142 formed of a single piece of sheet material with a loop therebetween at the outflow end OF (that is, at the distal margins of the leaflets 14a, 14b, 14c) will also be joined—by a positive seam as represented the joining line 20—at the inflow end IF so that the double-walled structure of the valvular sleeve 14 may be closed (also) at the inflow end IF.
A joining line 20 as exemplified in
By resorting to such an arrangement, the leaflets (which are double-walled due to the presence of the inner portion 141 and the outer portion 142) will behave in fact as a single (layered) laminar body e.g. avoiding the formation of pockets between the inner and outer portions 141, 142.
Also, the joining lines 24, 26 may be beneficial in facilitating bestowing onto the leaflet portions 14a, 14b, 14c their concave scoop-like configuration as exemplified in
The pattern of the joining lines 24, 26 (which may be either continuous or discontinuous, e.g. point-wise as exemplified in
In one or more embodiments, such pad members 28 may be generally crescent—shaped, semi-circular, semi-elliptical or eyelid-shaped (e.g. in the form of a shield), and may be scored or have notches cut in portions thereof, as schematically represented in parts a), b), c) and d) of
In one or more embodiments, the pad members 28 may include a spongy material.
In one or more embodiments, the pad members 28 may have a surface sculpturing as exemplified at 280 in part c) of
In one or more embodiments, the pad members 28 may include e.g. at their distal rim, at least one notch 282 which may bestow on the pad member an overall V or U shape. The notch or notches 282 may facilitate the closing and opening movement of the corresponding leaflet, that is the movement of the leaflet portions under fluid pressure between an inward condition to impede fluid flow from the outflow end OF to the inflow end IF and an outward condition to permit fluid flow from the inflow end IF to the outflow end OF.
In one or more embodiments, the pad members 28 may be retained at their location and prevented from being dislodged distally of the valvular sleeve 14 by the loop or fold between the inner portion 141 and the outer portion 142 at the outflow end OF of the valvular sleeve 14.
In one or more embodiments, the joining lines 24, 26 and/or the pad members 28 (possibly provided with the sculpturing 280 and/or the notch(es) 282) may be functional in bestowing onto the leaflets 14a, 14b, 14c a “bi-stable” behaviour thus making the leaflets 14a, 14b, 14c capable of alternatively “snapping open” under inflow-to-outflow fluid (e.g. blood) pressure and “snapping closed” under reversed outflow-to-inflow fluid pressure.
The valvular sleeve 14 as exemplified herein may include a plurality of (e.g., three) double-walled valve leaflets 14a, 14b, 14c (with the stent 16, if present, including a matching plurality (e.g., three) prongs 162) equally extending angularly 120° around the main axis X160.
One or more embodiments may include a different number of leaflets and/or leaflets of different sizes. For instance, embodiments for use e.g. in venous valves may include two leaflets or even just one leaflet. Valvular sleeves for implantation at, e.g., a mitral site may include a higher number of leaflets e.g. four leaflets, possibly of different sizes.
One or more embodiments are largely independent of the number and sizes of the leaflets in the valvular sleeve 14.
As shown in
The embodiment of
Such an hourglass-shaped tubular member T as shown in
The tapered tubular body of
The related disclosure provided in connection with
In one or more embodiments as exemplified in
In that way, the valvular sleeve 14 will essentially extend within a portion of the stent 16, that is with the stent 16 largely surrounding the valvular sleeve 14. However, the folded portions 140, will at least marginally extend at the outer surface of the stent 16 so that a peg member 144 may be inserted into each folded portion 140 to provide anchoring of the commissures of valvular sleeve 14 to the prongs 162.
That mounting arrangement may be applied also in the case on non-tapered (e.g. cylindrical) valvular sleeves 14/stents 16.
In one or more embodiments (related to a tapered valvular prosthesis 10 as exemplified in
The peg members 144 may be inserted wedge-like into the folded portions 140 in such a way that the folded portions 140 will be widening towards the outflow end OF of the valvular sleeve. The circumferential extension, and thus the radial size of the valvular sleeve 14 within the stent 16 will thus be smaller at the outflow end OF in comparison with the inflow end IF: this is because the folded portions 140 will “draw” more material of the valvular sleeve 14 out of the stent 16 at the outflow end OF than at the inflow end IF. The “effective” valvular sleeve 14 surrounded by the stent 16 will then have a tapered shape as in the case of the tapered tubular body of
In
Once formed into a ring or collar, the tubular member T4 will in fact have two opposed loop portions designated S2 and S1 in
As exemplified by a scissor K in
In one or more embodiments, the opposed walls S10 and S20 of the tubular member T4 may be left connected at both lines S2 and S1. This may apply e.g. to “stentless” valvular prostheses for which coupling to a support stent 16 may not be envisaged or to those embodiments were coupling with a stent 16 may occur either by causing the stent 16 to surround the valvular sleeve 14 (see e.g.
For instance, an arrangement wherein the inner and outer portions 141, 142 of the valvular sleeve 14 have a loop or fold therebetween at both the inflow end IF and the outflow end OF (that is at the distal margins of the leaflets 14a, 14b, 14c) may be adapted for coupling to a stent using the slit/aperture and peg arrangement as exemplified in
In one or more embodiments a double-walled tubular body as exemplified in
One or more embodiments may thus include a plurality of (e.g. three) valve leaflet portions extending distally of said inflow end towards distal margins at said outflow end.
In one or more embodiments, the valve leaflets may be displaceable under fluid pressure to an inward, “closed” condition wherein the distal margins of the leaflets coapt to impede fluid flow from said outflow end to said inflow end.
In one or more embodiments, the inner and outer portions 141, 142 of the (double-walled) leaflets 14a, 14b, 14c may be formed of a single piece of sheet material with a fold or loop (e.g. the folding line S2) therebetween at the outflow end OF (that is, at the distal margins of the leaflets 14a, 14b, 14c).
In the following, examples are described to facilitate the understanding of embodiments.
In some embodiments: A valvular sleeve for valvular prostheses including a tubular body extending between an inflow end and an outflow end, the tubular body including a sheet member folded at said outflow end, whereby the tubular body includes an inner tubular portion and an outer tubular portion surrounding the inner tubular portion.
In some embodiments: The valvular sleeve of Embodiment 1, wherein said inner and outer portions comprise either of:
In some embodiments: The valvular sleeve of Embodiment 1 or Embodiment 2, wherein said inner and outer portions are joined to each other, optionally by suture, at said inflow end.
In some embodiments: The valvular sleeve of Embodiment 1, wherein said inner and outer portions comprise respective wall portions of a tubular ribbon-like member, optionally having opposed ends joined to each other to form said tubular body.
In some embodiments: The valvular sleeve of any of the previous Embodiments, wherein said inner and outer portions include valve leaflet portions extending distally of said inflow end towards said outflow end, said valve leaflet portions displaceable under fluid pressure to an inward condition to impede fluid flow from said outflow end to said inflow end and an outward condition to permit fluid flow from said inflow end to said outflow end.
In some embodiments: The valvular sleeve of Embodiment 5, wherein said inner and outer portions are joined to each other, preferably by suture, at said valve leaflet portions.
In some embodiments: The valvular sleeve of Embodiment 6, wherein said inner and outer portions are joined to each other at said valve leaflet portions by at least one of:
In some embodiments: The valvular sleeve of any of Embodiments 5 to 7, including a pad member set between said inner and outer sheets at said valve leaflet portions.
In some embodiments: The valvular sleeve of any of the previous Embodiments, wherein said inner and outer portions comprise respective subsequent sections of an hourglass-shaped tubular sheet member overturned at an overturn line at the waistline of the hourglass shape, said overturn line being at said outflow end of the valvular sleeve, whereby said valvular sleeve has a tapered shape from said inflow end towards said outflow end.
In some embodiments: A prosthetic valvular device including:
In some embodiments: The prosthetic valvular device of Embodiment 10, including anchoring formations, optionally suture formations, anchoring said valvular sleeve to said stent.
In some embodiments: The prosthetic valvular device of Embodiment 10 or Embodiment 11, wherein said stent extends between said inner and outer portions of the valvular sleeve.
In some embodiments: The prosthetic valvular device of Embodiment 10 or Embodiment 11, wherein:
In some embodiments: The prosthetic valvular device of Embodiment 13, wherein:
In some embodiments: The prosthetic valvular device of any of embodiments 10 to 14, wherein said stent is collapsible.
Without prejudice to the underlying principles, the details and embodiments may vary, even significantly, with respect to what has been described by way of the example only, without departing from the extent of protection.
The extent of protection is defined by the annexed claims.
Number | Date | Country | Kind |
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102015000037126 | Jul 2015 | IT | national |
This application is a national stage application of PCT/IB2016/054281, filed Jul. 19, 2016, which claims priority to Italian application 102015000037126, filed Jul. 22, 2015, both of which are herein incorporated by reference in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2016/054281 | 7/19/2016 | WO | 00 |