Stent and securely-installed artificial valve replacement device having same

Abstract

A stent and a securely-installed artificial valve replacement device having the same, the stent being of a cylindrical structure; the top of the stent is provided with a fixed ear (60); the fixed ear (60) has a neck portion (601) connected to the top of the stent, and a head portion (602) engaged with the fixed head of the stent; the head portion (602) has a bending structure for improving the overall radial thickness; and the artificial valve replacement device is comprised of a stent and a prosthetic valve fixed on the stent. The stent with a bending structure overcomes the problem of easily disengaging from the fixed head of the stent, while not affecting the release of the stent.

Claims

1. A foldable stent, comprising: a cylindrical structure having a top edge, at least one fixed ear provided at the top edge, each fixed ear includes: a neck portion connected to the top edge of the stent, and a head portion configured to engage with a stent fixing head, the head portion having a width greater than a width of the neck portion in a circumferential direction of the stent, wherein each head portion has a fixed end connected to the neck portion and a free end extending from the fixed end, the free end being bent relative to the fixed end, and an overall radial thickness of the head portion being increased by the bent free end, and and wherein the fixed end and the free end of the head portion are arranged next to one another in a radial direction of the stent.

2. The stent according to claim 1, wherein the whole head portion or a part of the head portion is bent.

3. The stent according to claim 2, wherein a ratio of a radial thickness of the whole head portion or the part of the head portion that is bent to a radial thickness of the neck portion equals 2:1.

4. The stent according to claim 1, wherein the free end is formed by a top edge of the head portion bending towards the neck portion.

5. The stent according to claim 4, wherein a bent angle of the top edge is from 160-180 degrees.

6. The foldable stem according to claim 1, wherein the fixed end and the free end of the head portion are substantially parallel to each other.

7. The foldable stent according to claim 1, wherein the head portion is bent in an axial direction of the stent.

8. A stably-mounted artificial valve replacement device, comprising a stent according to claim 1 and a prosthesis valve fixed to the stent.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural schematic view of a stent of an artificial valve replacement device in the prior art;

(2) FIG. 2 is a structural schematic view of a stent fixing head in the prior art;

(3) FIG. 3 is a cut-away view of the stent fixing head shown in FIG. 2;

(4) FIG. 4 is a structural schematic view of a stent of an artificial valve replacement device of the present application;

(5) FIG. 5 is a structural schematic view of a first type of fixed ear of FIG. 4;

(6) FIG. 6 is a schematic view of mounting the fixed ear shown in FIG. 5 onto a transport system (according to a first fitting method);

(7) FIG. 7 is a schematic view of mounting the fixed ear shown in FIG. 5 onto a transport system (according to a second fitting method);

(8) FIG. 8 is a structural schematic view of a second type of fixed ear of FIG. 4;

(9) FIG. 9 is a schematic view of mounting the fixed ear shown in FIG. 8 onto a transport system (according to a first fitting method);

(10) FIG. 10 is a schematic view of mounting the fixed ear shown in FIG. 8 onto a transport system (according to a second fitting method);

(11) FIG. 11 is a structural schematic view of a third type of fixed ear of FIG. 4;

(12) FIG. 12 is a structural schematic view of a fourth type of fixed ear of FIG. 4;

(13) FIG. 13 is a schematic view of opening the stent of the artificial valve replacement device of the present application before the stent is released.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(14) The present application will be further described hereafter with reference to the accompany drawings and embodiments.

(15) An artificial valve replacement device of the present application comprises a stent and a prosthesis valve fixed on the stent.

(16) Taking an aortic stent as an example, a structure of the artificial valve replacement device of the present application will be described hereafter. However, it should be noted that the artificial valve replacement device of the present application is not limited to use the aortic stent, but can also use a pulmonary stent, a tricuspid valve stent, etc.

(17) As shown in FIG. 4, the stent (aortic stent) is a netlike cylindrical structure, which comprises an aortic stent 4, a valve stent 5, and an inflow tract stent 6 that are connected sequentially.

(18) The stent comprises a plurality of diamond unit meshes arranged continuously, and three hollow areas are arranged at a side wall of the valve stent 5. Due to the limit of the view angle, only two hollow areas 9a, 9b of the three hollow areas are visible in FIG. 4. The hollow areas are used to respectively accommodate a top end of a prosthesis valve when the prosthesis valve is opened. Each hollow area is formed by combining four adjacent diamond unit meshes together, that is, at least a part of the skeletons inside the hollow area are removed to form the hollow area. In this way, the stent is not only easy to process but also able to achieve a good overall strength.

(19) Of course, the shapes of the mesh structures of the stent are not limited to diamond, and can also be regular or irregular oval, round, rectangular, and so on, as long as they can meet the requirement for supporting force and compliance of the stent.

(20) A top edge of the aortic stent 4 is provided with at least one fixed ear 60, which is configured to engage within a positioning groove of a stent fixing head of a transport system when the stent is implanted into a human body.

(21) The fixed ear 60 is substantially T-shaped, in particular, the fixed ear 60 includes a neck portion 601 and a head portion 602, the neck portion 601 is connected with the top edge of the aortic stent 4, and the head portion 602 engages with a stent fixing head; a top end of the neck portion 601 of the fixed ear 60 is connected with a center of a bottom of the head portion 602, and the head portion 602 further comprises a bent structure that increases an overall radial thickness of the head portion 602.

(22) FIG. 5 illustrates a first embodiment of the bent structure of the head portion 602 of the fixed ear 60 of the present application. In this embodiment, the whole head portion 602 of the fixed ear is bent to be arc-shaped, and a concave portion of the arc shape is positioned towards an axis of the stent. In this way, an overall radial thickness H of the head portion 602 (i.e., a difference between a height of a middle portion of the arc shape and a height of either end of the arc shape) is increased. When the fixed ear 60 engages with a positioning groove, as shown in FIG. 7, a depth of a positioning groove 8 of a stent fixing head 7 can be increased appropriately (however, it is also possible that the depth is not increased), so that the head portion 602 of the fixed ear 60 is in tight contact with an inner wall of a sheath tube 14. Of course, when the depth of the positioning groove 8 is increased, the depth can be fit for the thickness of the head portion 602 of the fixed ear 60, as shown in FIG. 6; in this way, even though the sheath tube 14 is bent and/or deformed, the fixed ear 60 is not prone to disengage from the positioning groove 8, and thus the stent is prevented from disengagement.

(23) Even though the depth of the positioning groove 8 is unchanged, since the overall radial thickness of the head portion 602 is increased so that the radial thickness equals several times of a width of a clearance between the sheath tube 14 and the stent fixing head 7, requirement for the accuracy of the clearance can still be greatly reduced, and requirement for the accuracy of the sheath tube can also be reduced at an order of magnitude, such that the processing technology is simpler and easier to perform.

(24) FIG. 8 illustrates a second embodiment of the bent structure, wherein the head portion 602 of the fixed ear 60 is substantially wave-shaped, and wave peaks and wave troughs of the wave-shaped head portion 602 are alternately arranged along a circumference of the stent. In particular, two ends of the head portion 602 that abut a bottom of the positioning groove 8 are wave troughs of the head portion 602, so that the fixed ear 60 can be embedded in the positioning groove 8 of the stent fixing head 7 more stably. FIG. 9 and FIG. 10 show mounted states of the head portion 602 of the wave-shaped fixed ear 60 in the transport system when mounting the stent.

(25) In a third embodiment of the bent structure of the head portion 602, the head portion 602 of the fixed ear 60 is partially bent, in particular, two side edges of the head portion 602 are bent towards each other. As shown in FIG. 11, the two side edges of the head portion 602 are bent towards the same side, the bent angle of each side edge equals 180 degrees, and a thickness of the bent fixed ear 60 equals two times of a thickness of the fixed ear 60 before being bent.

(26) Of course, the two side edges of the head portion 602 can also be bent towards two opposite sides respectively, so that the head portion 602 is substantially S-shaped.

(27) FIG. 12 illustrates a fourth embodiment of the bent structure of the head portion 602 of the present application. In this embodiment, the top edge of the head portion 602 is bent towards the neck portion 601, the bent angle equals 180 degrees, and a thickness of the bent fixed ear 60 equals two times of a thickness of the fixed ear 60 before being bent; of course, a bent angle in the range of about 160180 degrees can also achieve good effect.

(28) Obviously, when the fixed ear 60 shown in FIG. 11 or FIG. 12 engages with the positioning groove 8, the aforementioned engaging ways (e.g., the first engaging way) can also be adopted, and these engaging ways do not need to be repeatedly detailed here.

(29) It should be noted that the bent structure of the head portion 602 of the fixed ear 60 of the present application is not limited to the above-described embodiments but can have many variations. For example, each of the two side edges of the head portion 602 of the fixed ear 60 shown in FIG. 11 is bent only once, actually, each of the two side edges can be bent twice or more times, so that a thickness of the bent fixed ear 60 with the multilayer laminate structure equals three or more times of a thickness of the fixed ear 60 before being bent.

(30) Furthermore, in the bent structure, the bending or curving angle of the head portion 602 can be adjusted according to actual situations.

(31) The number of the fixed ears 60 is usually three, as shown in FIG. 13, three fixed ears 60a, 60b, and 60c are provided. Heights of top edges of three fixed ears 60a, 60b, and 60c are different, for example, it can be seen from FIG. 13 that the fixed ear 60b is obviously higher than the fixed ear 60a, and the fixed ear 60c is obviously higher than the fixed ear 60b.

(32) A height H1 of the fixed ear 60c is a distance between a top edge of the aortic stent 4 and the top edge of the fixed ear 60c. In this embodiment, the height of the fixed ear 60c is about 7 mm, the height of the fixed ear 60b is about 5 mm, the height of the fixed ear 60a is about 2.8 mm, and a height H2 of the stent (without the heights of the fixed ears) is about 55 mm.

(33) It needs to be explained that the stent of the artificial valve replacement device is in a folded state when it is not used, that is, it is a compact tubular structure, and is usually fabricated by machining tubing made of memory metal material using laser cutting; while it is implanted into a human body and released, it will expand under the action of the body temperature and form a loose cylindrical structure. In the present application, if not specially described, all described structures of the artificial valve replacement device and the stent thereof refer to the structures having completely expanded in a human body.