Patent Application
20240016601
The present invention relates to the field of medical devices and, in particular, to artificial heart valve prostheses.
Heart valves include the aortic valve that connects the left ventricle to the aorta, the pulmonary valve that connects the right ventricle to the pulmonary artery, the mitral valve that connects the left atrium to the left ventricle and the tricuspid valve that connects the right atrium to the right ventricle. All these heart valves function like one-way valves and rhythmically open and close with the rhythmic contraction and dilation of the heart in the blood circulation, allowing smooth passage of blood through heart valves in one direction and preventing its passage in the opposite direction, hence to enable the blood to circulate in a certain direction within a body. Inflammation of heart valves may cause structural damage, fibrosis, adhesions, shortening, myxomatous lesions, ischemic necrosis, calcium precipitation and other problems affecting normal blood circulation, which are collectively called heart valve disease.
An artificial heart valve prosthesis is a device that can be implanted into the heart to function in place of the native heart valve. For severe valvular disease that cannot be recovered or functionally improved by valvuloplasty or valvular repair, it is necessary to replace the diseased native valve with an implanted artificial heart valve prosthesis. Such an artificial heart valve prosthesis includes a stent and a valve attached to an inner surface of the stent. In practical applications, limited by the material of the valve and other factors, commissural joints of the valve with the stent tend to be overstressed and calcified.
It is an object of the present invention to provide an artificial heart valve prosthesis, which has an extended life thanks to its ability of effective stress distribution within joints of a valve structure with a stent.
To this end, the present invention provides an artificial heart valve prosthesis, comprising:
Optionally, the artificial heart valve prosthesis may further comprise hinge sheets, which are at least partially arranged between the commissure and the flaps of the leaflet, wherein the hinge sheet is provided with a through hole for passage therethrough of the flap and wherein the hinge sheet is sutured at the first window.
Optionally, the hinge sheet may cover the first window. Alternatively, the flaps may be sutured to the hinge sheet.
Optionally, the second window may be delimited by side support arms arranged circumferentially around the stent, wherein:
Optionally, the flap may be sutured at the second window by a suture thread successively passed through the main segment of the leaflet, the second window, the through hole and the trailing portions of the flap.
Optionally, in the circumferential direction of the stent, edges of the through hole may be coincident with or lateral to edges of the second window.
Optionally, the flap may be provided with an engagement notch on a side thereof proximate an inflow end of the stent, which are located at a junction of the flap with the main segment and configured to engage the through hole and the second window.
Optionally, the commissure may be further provided with a third window, which are located on a side of the second window proximate an inflow end of the stent,
Optionally, the second window may be delimited by side support arms arranged circumferentially around the stent,
Optionally, the flap may be sutured at the second window by a suture thread successively passed through the main segment of the leaflet, the second window and the trailing portion of the flap.
To the above end, the present invention also provides another artificial heart valve prosthesis, comprising:
Optionally, the second windows may be delimited by side support arms arranged circumferentially around the stent, wherein:
Optionally, the flap may be sutured at the second window by a suture thread successively passed through the main segment of the leaflet, the second window, the through hole and the trailing portion of the flap.
Optionally, in the circumferential direction of the stent, edges of the through holes may be coincident with or lateral to edges of the second window.
Optionally, the flap may be provided with an engagement notch on a side thereof proximate an inflow end of the stent, which are located at a junction of the flap with the main segment and configured to engage the through hole and the second window.
Optionally, the commissure may be further provided with a third window, which are located on a side of the second window proximate an inflow end of the stent,
Compared with the prior art, the artificial heart valve prostheses of the present invention have the advantages as follows:
First, the artificial heart valve prosthesis includes a stent and at least two leaflets. The stent includes at least two commissures spaced circumferentially around the stent. The commissure is provided with a first window and a second window, which are arranged along an axial direction of the stent. The first window is located closer to an outflow end of the stent. The at least two leaflets are arranged circumferentially around the stent. Each of the leaflets includes a main segment and flaps arranged on opposite circumferential sides of the main segment. The main segment is disposed on an inner side of the stent, and the flap is passed through the second window and at least partially covers an outer surface of the commissure. The flap is sutured at the first window and the second window. In addition to being sutured at the second window, the flap is also sutured at the first window. In this way, stress is distributed across the joints of the leaflet with the stent (i.e., areas around the second window), resulting in an extended life of service of the leaflets. Moreover, since the first window is closer to the outflow end of the stent, the leaflet can be prevented from sagging during use of the artificial heart valve prosthesis.
Second, the artificial heart valve prosthesis may further include hinge sheet, which is at least partially arranged between the commissure and the flap to reduce friction between the flap and the stent. In particular, the second window may be delimited by side support arms arranged circumferentially around the stent. Moreover, the hinge sheet may at least partially cover an outer surface of the side support arms and completely covers outer side face and inner surface of the side support arm. Additionally, each of the flaps may include a head portion, a middle portion and a trailing portion, which are sequentially joined. The head portion may be inserted in the second window and the through hole, and the middle portion may extend over the outer surface, the outer side face and the inner surface of the side support arm so as to wrap a portion of the hinge sheet arranged on the side support aim. The trailing portions may overlap a portion of the main segment in the leaflet. With this arrangement, stress can be uniformly distributed across the entire commissure, thus effectively preventing stress concentration and improving the stent's durability.
Third, the flap may be overseamed with a suture thread that is successively passed through the main segment of the leaflet, the second window, the through hole and the trailing portion and then again through the main segment in such a manner the suture thread do not come into contact with the side support aims. In this way, the risk of the suture thread breaking due to rubbing against the side support arms is eliminated.
Fourth, the other artificial heart valve prosthesis includes a stent, hinge sheets and at least two leaflets arranged circumferentially around the stent. The stent includes at least two commissures, which are spaced circumferentially around the stent and provided with second windows. The hinge sheet at least partially covers an outer surface of the commissure and is provided with a through hole. Each of the leaflets includes a main segment and flaps arranged on opposite circumferential sides of the main segment. The main bodies are disposed on an inner side of the stent, and the flap is passed through the second window and the through hole and at least partially covers an outer surface of the hinge sheet. Moreover, the flaps are sutured at the second windows. Through arranging the hinge sheet between the commissure and the flap of the leaflet, friction between the commissure and the flap can be effectively reduced, resulting in an extended life of service of the leaflet.
The accompanying drawings are provided to facilitate a better understanding of the present invention and do not limit the scope thereof in any sense, in which:
Particular embodiments of the present invention will be described below by way of specific examples. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will readily realize other advantages and benefits provided by the present invention. The present invention may also be otherwise embodied or applied through different embodiments, and various modifications or changes may be made to the details disclosed herein from different points of view or for different applications, without departing from the spirit of the present invention. It should be noted that the accompanying drawings are provided herein merely to schematically illustrate the basic concept of the present invention. Accordingly, they only show components relating to the present invention but not necessarily depict all the components as well as their real shapes and dimensions in practical implementations. In practice, the configurations, counts and relative scales of the components may vary arbitrarily and their arrangements may be more complicated.
In the following, each of the embodiments is described as having one or more technical features. However, this does not mean that the present invention must be practiced necessarily with all such technical features, or separately with some or all the technical features in any of the embodiments. In other words, as long as the present invention can be put into practice, a person skilled in the art may choose some or all of the technical features in any of the embodiments or combine some or all of the technical features in different embodiments based on the teachings herein and depending on relevant design specifications or the requirements of practical applications. In this way, the present invention can be carried out more flexibly.
As used herein, the singular forms “a”, “an” and “the” include plural referents, and the plural form “a plurality of” means “two or more”, unless the context clearly dictates otherwise. As used herein, the term “or” is generally employed in the sense including “and/or”, unless the context clearly dictates otherwise. The terms “mounting”, “coupling” and “connection” should be interpreted in a broad sense. For example, a connection may be a permanent, detachable or integral connection, or a mechanical or electrical connection, or a direct or indirect connection with one or more intervening media, or an internal communication or interaction between two elements. Those of ordinary skill in the art can understand the specific meanings of the above-mentioned terms herein, depending on their context.
As used herein to describe an artificial heart valve prosthesis, the term “inner” refers to a direction toward a central axis of the prosthesis, and the term “outer” refers to a direction away from the central axis.
Objects, advantages and features of the present invention will become more apparent upon reading the following more detailed description of the present invention, which is made with reference to the accompanying drawings. Note that the figures are provided in a very simplified form not necessarily drawn to exact scale and for the only purpose of facilitating easy and clear description of the embodiments. Throughout the annexed figures, like numerals indicate like elements.
Any valve mentioned in the following description refers to an artificial heart valve, unless it is stated as a native valve.
Referring to
With particular reference to
Optionally, the first window 1110 may be a circular opening, and the second window 1120 may be a rectangular opening extending along the axial direction of the stent 1000. In other implementations, the first window 1110 may be otherwise shaped, such as a rectangle. Alternatively, the second window 1120 may have another elongate shape, such as oblong.
Referring to
It would be appreciated that the outer surface of the hinge sheet 2000 is a surface thereof facing away from the respective commissure 1100. Moreover, each hinge sheet 2000 sutured at the first window 1110 means that a suture thread is passed through the first window 1110 so as to suture the hinge sheet 2000 to the commissure 1100 Similarly, each flap 3120 sutured at the first window 1110 means that a suture thread passed through the first window 1110 so as to suture the flap 3120 to the commissure 1100. Additionally, each flap 3120 sutured at the second window 1120 means that a suture thread is passed through the second window 1120 so as to suture the flap 3120 to the commissure 1100. Further, in this embodiment, the flaps 3120 may be additionally sutured to the hinge sheet 2000 to facilitate relative positioning of them so that they stay at stable relative positions during the subsequent suturing of them to the commissures 1100. Furthermore, in order to enable successful passage of the flaps 3120 through the second windows 1120 and the through holes 2100, the through holes 2100 are preferably elongate hole along the axial direction of the stent 1000, and the through holes 2100 and the second windows 1120 are properly arranged so that a part of the second windows 1120 is exposed and not covered by the respective hinge sheets 2000.
In the artificial heart valve prosthesis according to this embodiment, the hinge sheets 2000 can distribute stress within joints of the leaflets 3100 with the stent 1000 (i.e., around the second windows 1120), resulting in an extended service life of the leaflets 3100. Moreover, at least one of the hinge sheets 2000 and the flaps 3120 is sutured at the first windows 1110, effectively preventing the valve 3000 from sagging, when it closes, due to blood pressure and thereby improving its use. The present invention is not limited to any particular material of the hinge sheets 2000, and they may be made of either a polymer material or a natural biological material.
Optionally, with continued reference to
Referring back to
Each flap 3120 includes a head portion 3121, a middle portion 3122 and a trailing portion 3123, which are sequentially joined together. The head portion 3121 is inserted in both the respective second window 1120 (i.e., the head portion 3121 covers the inner side face 1121a of the respective side support arm 1121) and the respective through hole 2100. The middle portion 3122 extends over the outer surface 1121b, the outer side face 1121c and the inner surface 1121d of the respective side support arm 1121 so as to surround the portion of the respective hinge sheet 2000 arranged on the respective side support arm 1121. The trailing portion 3123 overlaps a part of the main segment 3110 of the corresponding leaflet 3100. In this way, the portions of each hinge sheet 2000 arranged on the respective side support arms 1121 of the respective second window 1120 are completely wrapped by the respective leaflet 3100, facilitating uniform distribution of stress at the joints of the leaflets 3100 with the stent 1000 across the entire commissures 1100. This can avoid stress concentration and enhance durability of the stent 1000. In addition, since the hinge sheets 2000 cover the outer surfaces 1121b, the outer side faces 1121c and the inner surfaces 1121d of the side support arms, the side support arms 1121 are separated from the flaps 3120, avoiding friction from occurring between the side support arms 1121 and the flaps 3120, and extending the life of the leaflets 3100.
Further, since the trailing portions 3123 of the flaps 3120 overlap portions of the main bodies 3110, the flaps 3120 may be overseamed with suture threads 4000. As shown in
In order to enable the flaps 3120 to be neatly overseamed at the second windows 1120, the through holes 2100 in the hinge sheets 2000 are preferred to have a width greater than or equal to a width of the second windows 1120. Here, the widths of the through holes 2100 and the second windows 1120 refer to their extents in the circumferential direction of the stent 1000. As such, in the circumferential direction of the stent 1000, edges of the through holes 2100 are located laterally to the second windows 1120, or coincide with edges of the second windows 1120.
Those skilled in the art would appreciate that the artificial heart valve prosthesis has equal numbers of leaflets 3100, hinge sheets 2000 and commissures 1100, which may be determined as required by practical applications. For example, when the artificial heart valve prosthesis is used to replace a mitral valve, there may be two or more leaflets 3100, hinge sheets 2000 and commissures 1100. As another example, when the artificial heart valve prosthesis is used to replace a tricuspid valve, there may be three or more leaflets 3100, hinge sheets 2000 and commissures 1100. Generally, in the artificial heart valve prosthesis, the multiple commissures 1100 are arranged on the same circumference.
In the context of the artificial heart valve prosthesis including two leaflets 3100, two hinge sheets 2000 and two commissures 1100 in the stent 1000 as an example, assembly of the artificial heart valve prosthesis will be described below with reference to
In the following description, for ease of distinction, the two leaflets 3100 are referred to respectively as a first leaflet 3100a and a second leaflet 3100b, the two flaps 3120 of the first leaflet 3100a as a first left flap 3120a and a first right flap 3120b, the two flaps 3120 of the second leaflet 3100b as a second left flap 3120c and a second right flap 3120d, and the two hinge sheets 2000 as a first hinge sheet 2000a and a second hinge sheet (not shown).
At first, as shown in
Subsequently, the first right flap 3120b is bent to the left, and the first hinge sheet 2000 is sutured to the first right flap 3120b with a suture thread 4000. Similarly, the second left flap 3120c is bent to the right, and the first hinge sheet 2000a is sutured to the second left flap 3120c with a suture thread 4000 (see
The above process is then repeated to hinge the first left flap 3120a of the first leaflet 3100a and the second right flap 3120d of the second leaflet 3100b to the second hinge sheet.
After that, the first hinge sheet 2000a, the first right flap 3120b and the second left flap 3120c are inserted, as a whole from the inner side of the stent 1000, through one of the second windows 1120 and then straighten the first hinge sheet 2000a, the first right flap 3120b and the second left flap 3120c (see
Next, the hinge sheets 2000 and the flaps 3120 are bent in the manner as shown in
After that, upper portions of the hinge sheets 2000 are sutured to the respective first windows 1110 (not shown) with suture threads. Afterward, the flaps 3120 are sutured down to the respective second windows 1120 along the axial direction of the stent 1000 in the manner as described above. Finally, lower portions of the hinge sheets 2000 are sutured at the respective third windows 1130 (not shown).
Preferably, the flaps 3120 are provided with, on their side closer to the inflow end 1001 of the stent 1000, engagement notches 3130 at their junctions with the main bodies 3110, which are adapted for location during assembly. Specifically, during assembly of the leaflets 3100 with the hinge sheets 2000, the engagement notches 3130 may engage the through holes 2100 of the hinge sheets 2000. Moreover, during assembly of the leaflets 3100 and the hinge sheets 2000 with the stent 1000, the engagement notches 3130 may engage lower edges of the second windows 1120.
Further, the main segment 3110 of each leaflet 3100 has a fixed edge 3111 and a free edge 3112. The fixed edge 3111 is disposed closer to the inflow end 1001 of the stent 1000 and is attached to the stent 1000. The free edge 3112 is disposed closer to the outflow end 1002 of the stent 1000. When the valve 3000 opens, the free edges 3112 of all the leaflets 3100 separate from one another. When the valve 3000 closes, the free edges 3112 of all the leaflets 3100 fit together. Preferably, in the axial direction of the stent 1000, a distance from the free edges 3112 to the outflow end 1002 of the stent 1000 is greater than a minimum distance from the flaps 3120 of the leaflets 3100 to the outflow end 1002. With this arrangement, in the closed configuration of the valve 3000, the leaflets 3100 are pulled at locations lower than locations where the stent 1000 is pulled. This can reduce stress on the stent 1000 and improve durability of the stent 1000.
Preferably, each fixed edge 3111 is substantially a V-shaped structure with a rounded corner. This shape of the fixed edges 3111 can reduce stress on the leaflets 3100 and improve durability of the valve 3000. Moreover, it can mitigate creasing and wrinkling of central portions of the leaflets 3100. This can reduce early calcification and the amount of material used.
Further, as shown in
It is to be noted that in the foregoing embodiments, the hinge sheets 2000 are not mandatory. In alternative implementations, they may be omitted. In these cases, the flaps 3120 of the leaflets 3100 may be brought into direct contact with the commissures 1100 of the stent 1000.
Embodiments of the present invention also provide another artificial heart valve prosthesis, which is substantially the same as the artificial heart valve prosthesis according to the above embodiments, except that no first windows are formed in the stent. In other words, the artificial heart valve prosthesis according to these embodiments includes: a stent comprising at least two commissures, which are spaced circumferentially around the stent, each of the commissures comprising a second window; hinge sheets, each covering at least a part of an outer surface of a respective one of the commissures and comprising a through hole; and at least two leaflets disposed circumferentially around the stent, each of the leaflets including a main segment and flaps arranged on opposite circumferential sides of the main segment, the main segment disposed on an inner side of the stent, each of the flaps passed through the second window of a respective one of the commissures and the through hole of a respective one of the hinge sheets and covering at least a part of an outer surface of the respective hinge sheet, the flaps are sutured at the second window.
It would be appreciated that, as each hinge sheet covers at least a part of the outer surface of the respective commissure and each flap covers at least a part of the outer surface of the respective hinge sheet, the hinge sheets are at least partially situated between the commissures and the flaps. In this way, when suturing the flaps at the second windows, the hinge sheets are sandwiched and secured between the flaps and the commissures.
For other structural details of this artificial heart valve prosthesis, reference can be made to the description of the preceding embodiments, and further description thereof is therefore omitted here. Although the present invention has been disclosed hereinabove, it is not limited to the above disclosure. Those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope thereof. Accordingly, it is intended that any and all such changes and modifications also fall within the scope of the present invention as defined by the appended claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202011459644.9 | Dec 2020 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2021/128826 | 11/4/2021 | WO |
