Multi-stent valve expander and valve expansion system

Abstract

The present invention provides a multi-stent valve dilator and a valve dilation system. The valve dilator includes an expandable outer stent and at least one expandable inner stent arranged in the outer stent. The outer stent includes a first distal end and a first proximal end opposite to each other, and at least two expansion arms connected between the first distal end and the first proximal end. At least one expansion arm is provided with a cutting portion on a side away from the other expansion arms. The inner stent includes a second proximal end and a second distal end opposite to each other, and at least one reinforcing arm connected between the second proximal end and the second distal end. The reinforcing arm at least partially fits the expansion arm and is fixedly connected. The second proximal end is fixedly connected to the first proximal end, and the second distal end is fixedly connected to the first distal end. In the valve dilator of the present invention, the outer stent and the inner stent jointly provide support for the expansion arm, and the expansion arm is less likely to deform, which can prevent the expansion arm of the outer stent from collapsing during the expansion process, reduce valve damage, and improve the success rate of the operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular, relates to a multi-stent valve dilator and a valve dilation system. Background Art

[0002] Valvular stenosis, such as aortic stenosis, is a common valvular disease. Aortic stenosis is mainly caused by the sequelae of rheumatic fever, congenital aortic valve structural abnormalities or senile aortic valve calcification. On the one hand, it can cause insufficient blood supply to various organs in the body, and on the other hand, it can cause a relative decrease in coronary blood flow, resulting in insufficient oxygen supply to the heart, which may eventually lead to complications such as arrhythmia, pulmonary hypertension, coronary heart disease, and heart failure.

[0003] In the prior art, aortic valve stenosis is treated by a radially expandable structure that can change between a collapsed position and an expanded position. The expandable structure is composed of a plurality of expansion arms, each expansion arm including a proximal segment, a distal segment and an intermediate segment between the proximal segment and the distal segment. The expandable structure can be radially expanded or collapsed by operation to perform ablation and cutting of the valve adhesions. However, since the middle segment of the expansion arm only has support points near its proximal and distal ends, the rest of the segment is suspended. The structure that is suspended in the middle and supported at both ends can be constructed into a simply supported beam model with a rectangular cross-section in engineering mechanics. In actual use, as the middle segment of the beam, its middle portion will be subject to the force from the valve / tissue during operation. See. Figure 1 In this model, the two ends of the beam are supported at points A and B, and are subject to a support force F A and F B , the middle part of the beam will be subjected to a concentrated load F at point C. If the length of the middle section is l, the middle part will be subjected to the maximum bending moment M max =F*l / 4, the middle section is prone to deformation and collapse. Moreover, for a constantly swinging valve, the cutting part of the expansion arm with insufficient support is difficult to keep aligned with the cutting position of the valve in the flowing blood, which can easily damage the valve during the ablation cutting process and prolong the operation time. Summary of the invention

[0004] A main purpose of the present invention is to overcome the defect that the expansion arms of the radially expandable structure in the prior art are easily deformed and collapsed, and to provide a multi-stent valve expander, comprising:

[0005] An expandable external stent, comprising a first distal end and a first proximal end opposite to each other, and at least two expansion arms connected between the first distal end and the first proximal end, at least one of the expansion arms being provided with a cutting portion on a side away from the other expansion arms; and

[0006] At least one expandable inner support is arranged in the outer support, and the inner support includes a second proximal end and a second distal end relative to each other, and at least one reinforcement arm connected between the second proximal end and the second distal end, the reinforcement arm at least partially fits the expansion arm and is fixedly connected, the second proximal end is fixedly connected to the first proximal end, and the second distal end is fixedly connected to the first distal end.

[0007] The present invention also provides a valve expansion system, including a tube body assembly and a valve expander of the above structure, the first proximal end is fixedly sleeved on the second proximal end, the first distal end is fixedly sleeved on the second distal end, the tube body assembly includes a limiting head, an inner tube, a first intermediate tube and an outer tube, the inner tube is slidably arranged in the first intermediate tube, the first intermediate tube is slidably arranged in the outer tube, the inner tube passes through the first proximal end, the second proximal end, and the second distal end in sequence and extends out of the first distal end to be fixedly connected to the limiting head, and the first intermediate tube is fixedly connected to the first proximal end.

[0008] The multi-stent valve dilator and valve dilation system of the present invention utilize the cutting portion of the dilation arm to gradually cut and continuously dilate the valve adhesion. The outer stent and the inner stent jointly provide support for the dilation arm. The reinforcing arm of the inner stent is fixed to the dilation arm, which can increase the supporting force of the outer stent during the process of cutting and dilating the valve, and can add a force fulcrum on the dilation arm to prop up the dilation arm. Under the same concentrated load, the dilation arm has supporting force and is less likely to deform, thereby preventing the dilation arm from collapsing due to the valve resistance and insufficient supporting force of the outer stent during the dilation process, effectively improving the stability of the dilation arm, reducing valve damage, and improving the success rate of the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0011] Figure 1 The figure is a schematic diagram of the force model of the expansion arm of the existing valve expander.

[0012] Figure 2 Schematic diagram of the structure of the valve expander of Example 1.

[0013] Figure 3 This is a schematic diagram of an exploded view of the valve expander of Example 1.

[0014] Figure 4 It is a schematic structural diagram of the outer bracket of the first embodiment.

[0015] Figure 5 It is a side view of the outer bracket of the first embodiment.

[0016] Figure 6 It is a schematic diagram of the structure of the inner support of the first embodiment.

[0017] Figure 7 It is a front view of the inner bracket of the first embodiment.

[0018] Figure 8 FIG. 4 is another schematic diagram of the structure of the valve expander of the first embodiment.

[0019] Fig. 9 Another front view of the valve dilator of the first embodiment.

[0020] Fig.10 This is a simplified diagram of the force model of the expansion arm of the valve expander of Example 1.

[0021] Fig.11 Schematic diagram of the structure of the valve expansion system of Example 1.

[0022] Fig.12 for Fig.11 A partial enlarged view of part A in the middle.

[0023] Fig.13 for Fig.11 Schematic diagram of the exploded view of part A in the middle.

[0024] Fig.14 This is a schematic diagram of the working scene of the valve expansion system of Example 1.

[0025] Fig.15 This is a schematic diagram of the working scene of the valve expansion system of Example 2.

[0026] Fig.16 This is a schematic diagram of the working scene of the valve expansion system of Example 3.

[0027] Fig.17 This is a schematic diagram of the working scene of the valve expansion system of Example 4.

[0028] Fig.18 It is a top view of the embolic filter of the fourth embodiment.

[0029] Fig.19 It is a side view of the embolic filter of the fourth embodiment. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be understood that the directions or positional relationships indicated by “front”, “back”, “up”, “down”, “left”, “right”, “longitudinal”, “horizontal”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “head”, “tail”, etc. are based on the directions or positional relationships in the drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the technical solution, and do not indicate that the device or element referred to must have a specific direction, and therefore should not be understood as a limitation on the present invention.

[0032] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intervening elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0033] In the description of the present invention, it still needs to be explained that the proximal end refers to the end of the instrument or component close to the operator, and the distal end refers to the end of the instrument or component away from the operator; the axial direction refers to the direction parallel to the line connecting the distal and proximal centers of the instrument or component, the radial direction refers to the direction perpendicular to the axial direction, and the circumferential direction refers to the direction surrounding the axial direction.

[0034] In order to overcome the defect of the prior art that the expansion arm of the valve expander is easy to collapse during the cutting process, the present invention discloses a multi-stent valve expander and a valve expansion system. The present invention is described below through specific embodiments in conjunction with the drawings of the specification.

[0035] Embodiment 1

[0036] See also Figures 2 to 9The present invention provides a multi-stent valve expander 12, comprising an expandable outer stent 121 and at least one expandable inner stent 122. The outer stent 121 comprises a first distal end 1212 and a first proximal end 1211 opposite to each other, and at least two expansion arms 1210 connected between the first distal end 1212 and the first proximal end 1211. At least one expansion arm 1210 is provided with a cutting portion 1215 on a side away from the other expansion arms 1210. The inner stent 122 is arranged in the outer stent 121, and the inner stent 122 comprises a second proximal end 1221 and a second distal end 1222 opposite to each other, and at least one reinforcing arm 1220 connected between the second proximal end 1221 and the second distal end 1222. The reinforcing arm 1220 at least partially fits the expansion arm 1210 and is fixedly connected, the second proximal end 1221 is fixedly connected to the first proximal end 1211, and the second distal end 1222 is fixedly connected to the first distal end 1212.

[0037] The technical solution of this embodiment utilizes the cutting portion 1215 of the expansion arm 1210 to gradually cut and continuously expand the valve adhesion. The external support 121 and the internal support 122 jointly provide support for the expansion arm 1210. The reinforcing arm 1220 of the internal support 122 is fixed to the expansion arm 1210, which can increase the supporting force for the external support 121 during the process of cutting and expanding the valve, and can add a force fulcrum on the expansion arm 1210 to prop up the expansion arm 1210. Under the same concentrated load, the expansion arm 1210 has supporting force and is less likely to deform, thereby preventing the expansion arm 1210 from collapsing due to the valve resistance and insufficient supporting force of the external support 121 during the expansion process, effectively improving the stability of the expansion arm 1210, reducing valve damage, and improving the success rate of the operation.

[0038] The valve expander 12 is configured as a multi-stent structure, the purpose of which is to increase the support force of the external stent 121 during the valve expansion process, thereby preventing the external stent 121 from collapsing due to the inability to support and continue to expand the valve due to weak support force and large external resistance during the expansion process. Fig.10 The two ends of the expansion arm 1210 are connected to the first proximal end 1211 and the first distal end 1212, respectively, that is, the two end fulcrums of the beam are point A and point B, and are supported by the support force F A and F B When the inner support 122 is present, an upward support force F is added to the beam at point C. C , the simply supported beam model is transformed into an indeterminate beam, that is, an additional constraint F is added C , thereby improving the stability of the beam.

[0039] The valve dilator 12 in this embodiment is a double-stent structure, including an outer stent 121 and an inner stent 122 coaxially fixed therein. Of course, it is conceivable that this is not limited to a double-stent structure, and a three-stent structure is also applicable to the present invention, that is, the valve dilator 12 includes an outer stent 121 and two inner stents 122 coaxially fixed therein. Of course, the number of the inner stents 122 can also be three, or even more than three.

[0040] Considering the anatomical structure of the valve, the number of expansion arms 1210 of the outer support 121 may be less than or equal to the number of leaflets constituting the valve, for example, the leaflets of the mitral valve are two, and the leaflets of the aortic valve, tricuspid valve, and pulmonary valve are three, and considering that the inner support 122 is arranged inside the outer support 121, the number of expansion arms 1210 is at least two. The expansion arms 1210 may radially expand into the calcified junction of adjacent leaflets, and the adhesion site at the junction of adjacent leaflets may be cut by the cutting portion 1215, for example, mechanical cutting or ablation cutting.

[0041] The expansion arms 1210 of the external support 121 can be distributed at intervals along the circumference, preferably evenly arranged in the circumferential direction. Of course, the expansion arms 1210 can also be arranged non-uniformly in the circumferential direction. The structures of two and three expansion arms 1210 can be used for bicuspid valve stenosis and tricuspid valve stenosis, respectively. Since the cutting portion 1215 of the two or three expansion arms 1210 does not circumferentially form a cylindrical shape similar to the middle part of the balloon, the cutting portion 1215 of the valve dilator 12 can accurately fit into the junction gap between two adjacent leaflets to cut the calcified adhesion part at the junction, thereby achieving the purpose of expanding the valve orifice area and alleviating a series of adverse symptoms caused by stenosis. It is worth noting that the number of expansion arms 1210 should not be set too much to prevent all expansion arms 1210 from circumferentially contacting the leaflets like a balloon, and unable to enter the junction gap between adjacent leaflets.

[0042] Considering the actual radial size of the valve orifice of the human body, the maximum radial size of the outer diameter of the outer support 121 in the natural state should preferably be between 10-25 mm. Considering that the outer support 121 will expand radially when subjected to axial compression force, it is more preferably between 15-20 mm.

[0043] The number of the reinforcing arms 1220 of the inner bracket 122 may be one, and the reinforcing arm 1220 at least partially fits and is fixedly connected to one of the expansion arms 1210. Preferably, to ensure the overall stability of the outer bracket 121, the number of the reinforcing arms 1220 is consistent with the number of the expansion arms 1210, and the reinforcing arms 1220 are evenly spaced and fixedly connected along the circumferential direction like the expansion arms 1210.

[0044] The maximum radial dimension of the outer diameter of the inner bracket 122 in its natural state should be equal to the maximum radial dimension of the inner diameter of the outer bracket 121 in its natural state, so as to ensure that when the inner bracket 122 is inserted into the outer bracket 121 in its natural state, the outer wall of the reinforcing arm 1220 of the inner bracket 122 can just fit on the inner wall of the expansion arm 1210 of the outer bracket 121, so as to better fix and connect the two brackets together. Figure 2 and Figure 3 The length of the expansion arm 1210 is slightly greater than the length of the reinforcement arm 1220 to ensure that the fitting length of the two is larger and the support capacity of the expansion arm 1210 is stronger. Figure 8 and Fig. 9 In some embodiments, the fitting length between the reinforcing arm 1220 and the expansion arm 1210 is relatively small. In this case, the fitting fixing portion is arranged in the middle of the reinforcing arm 1220 to ensure that the reinforcing arm 1220 supports the expansion arm 1210 in a balanced manner.

[0045] See also Figure 4 and Figure 5 , the expansion arm 1210 includes a cutting segment 1214 and two first support segments 1213 respectively arranged at both ends of the cutting segment 1214. The other end of one of the first support segments 1213 is connected to the first proximal end 1211, and the other end of the other first support segment 1213 is connected to the first distal end 1212, and the cutting portion 1215 is arranged on the cutting segment 1214. It can be understood that the first support segment 1213 near the first proximal end 1211 is connected to the first proximal end 1211 at one end and connected to the cutting segment 1214 at the other end. The first support segment 1213 near the first distal end 1212 is connected to the first distal end 1212 at one end and connected to the cutting segment 1214 at one end. In this way, the function of the first support segment 1213 is to support the two ends of the cutting segment 1214. The cutting portion 1215 is arranged in the middle of the cutting segment 1214, which makes it easier for the cutting portion 1215 to align with the adhesion site at the junction of adjacent leaflets for cutting.

[0046] The expansion arm 1210 is arranged in sections. When the first proximal end 1211 and the first distal end 1212 move relative to each other axially, the radial distance between one end of each first support segment 1213 connected to the corresponding cutting segment 1214 and the central axis X of the outer support 121 (coinciding with the central axis Z of the valve expander) changes to adjust the radial distance between the cutting segment 1214 and the central axis X. Specifically, when the first proximal end 1211 approaches the first distal end 1212 axially, the axial distance between the first proximal end 1211 and the first distal end 1212 decreases, and the radial distance between one end of each first support segment 1213 connected to the corresponding cutting segment 1214 and the central axis X increases, and the radial distance between the cutting segment 1214 and the central axis X increases accordingly, so that the cutting portion 1215 on the cutting segment 1214 can perform progressive cutting on adhesions at different radial positions on the junction of adjacent leaflets to adapt to the physiological and anatomical differences of different individual valves (progressive cutting means first maintaining a radial distance between the cutting segment 1214 and the central axis X, and after cutting for a certain period of time, slightly increasing the radial distance between the cutting segment 1214 and the central axis X, and continuing to cut, and this cycle is repeated). When the first proximal end 1211 moves axially away from the first distal end 1212, the axial distance between the first proximal end 1211 and the second distal end 1222 increases, and the radial distance between one end of each first support segment 1213 connected to the corresponding cutting segment 1214 and the central axis X decreases, so that the radial distance between the cutting segment 1214 and the central axis X decreases accordingly, so as to facilitate the storage of the valve expander 12.

[0047] It can be understood that the cutting segment 1214 of the expansion arm 1210 is substantially parallel to the central axis X of the outer support 121, that is, the distance between any point of the cutting segment 1214 and the central axis X is substantially the same, with a deviation of less than 0.5 mm. Specifically, when the valve dilator 12 is in a natural state, the first support segment 1213 is tilted outward relative to the central axis X of the outer support 121 to form an angle, the angle range is 30-60°, and the cutting segment 1214 is substantially parallel to the central axis X. When the valve dilator 12 is in a cutting state, the outer support 121 is radially expanded or contracted, and the radial distance between the cutting segment 1214 and the central axis X is adjusted by changing the radial distance between one end of each first support segment 1213 connecting the corresponding cutting segment 1214 and the central axis X, so that the cutting segment 1214 can remain substantially parallel to the central axis X.

[0048] In this embodiment, the cutting segment 1214 is basically a straight rod parallel to the axial direction. Of course, it is foreseeable that in other embodiments, it can also be a wavy rod or other forms of rods, as long as the cutting segment 1214 meets the mechanical requirements used here to ensure that it will not break during the expansion and contraction process. Specifically, the overall length of the cutting segment 1214 should preferably be between 10-30 mm. Considering the height of the leaflet when it moves in the body, the length is more preferably between 15-25 mm. The width of the cutting segment 1214 should preferably be between 0.8-1.5 mm, and the wall thickness is preferably between 0.3-0.5 mm.

[0049] See also Figure 4 and Figure 5 Each first support segment 1213 includes two support rods 12131, one end of the two support rods 12131 is joined and fixedly connected to one end of the cutting segment 1214, and the other ends of the two support rods 12131 are joined and fixedly connected to the first proximal end 1211 or the first distal end 1212. Of course, each first support segment 1213 can be a single support rod.

[0050] Specifically, the first support section 1213 can be composed of two support rods 12131 that extend radially outward along the axial direction of the outer bracket 121 and finally converge. One end of the two support rods 12131 forms a first intersection 12132 with the cutting section 1214, and the other end forms a second intersection 12133 with the first proximal end 1211 or the first distal end 1212. The middle of each support rod 12131 protrudes away from the other support rod 12131, and the two support rods 12131 are similar to a rhombus. One end of the two support rods 12131 gathers at one end of the cutting section 1214 to form the first intersection 12132, and the other end gathers at the first proximal end 1211 or the first distal end 1212 to form the second intersection 12133. The first support segment 1213 is a structure that separates and then gathers together, which increases the stability of the valve dilator 12, especially the stability when the valve dilator 12 is axially contracted, and greatly reduces the torsional deformation phenomenon that may occur to the valve dilator 12 during axial contraction.

[0051] In this embodiment, the first distal end 1212 and the first proximal end 1211 are hollow tubular structures, and hollow grooves are provided in the circumference of the first distal end 1212 and the first proximal end 1211. Specifically, spiral grooves, zigzag grooves, mesh grooves or other forms of hollow grooves are processed on the tube walls of the first distal end 1212 and the first proximal end 1211. Preferably, the hollow grooves are spiral. The hollow grooves can increase the surface roughness of the first proximal end 1211 and the first distal end 1212, ensure the connection firmness and material adhesion of the valve dilator 12 when it is connected to the relevant structures on the conveying device, and enhance its anti-pull-off ability.

[0052] See also Figure 6 and Figure 7 The structure of the inner support 122 is similar to that of the outer support 121. The inner support 122 includes a second proximal end 1221, a second distal end 1222 and a reinforcing arm 1220 connected between the second proximal end 1221 and the second distal end 1222.

[0053] Specifically, the reinforcing arm 1220 includes a reinforcing section 1223 and two second supporting sections 1224 respectively provided at both ends of the reinforcing section 1223. The other end of one of the second supporting sections 1224 is connected to the second proximal end 1211, and the other end of the other second supporting section 1224 is connected to the second distal end 1212.

[0054] It is understandable that the second support segment 1224 of the inner support 122 can be formed by extending and gathering two support rods like the first support segment 1213 of the outer support 121. The specific structure is described above and will not be described in detail here. Of course, the second support segment 1224 can also be formed by a single support rod. Specifically, the single support rod is formed by the second proximal end 1221 or the second distal end 1222, extending radially outward along the axis, and finally intersecting with the two ends of the reinforcement segment 1223 of the inner support 122. The reinforcement segment 1223 is a straight rod parallel to the central axis Y of the inner support 122 (coinciding with the central axis Z of the valve dilator 12), which facilitates the fixed connection between the reinforcement segment 1223 and the cutting segment 1214. In order to facilitate the connection between the reinforcing section 1223 and the cutting section 1214, the width of the reinforcing section 1223 should be consistent with the width of the cutting section 1214, the length of the reinforcing section 1223 should be less than or equal to the length of the cutting section 1214, and the reinforcing section 1223 should be attached to and fixedly connected with at least part of the cutting section 1214.

[0055] See also Figure 2 and Figure 3 , similar to the structure of the outer bracket 121, the second proximal end 1221 and the second distal end 1222 of the inner bracket 122 are also hollow tubular structures, and hollow grooves are provided in the circumference of the second proximal end 1221 and the second distal end 1222. The outer diameter of the second proximal end 1221 should be smaller than the inner diameter of the first proximal end 1211, and the outer diameter of the second distal end 1222 should be smaller than the inner diameter of the first distal end 1212, so that the first proximal end 1211 can be sleeved on the second proximal end 1221 and fixed, and the first distal end 1212 can be sleeved on the second distal end 1222 and fixed. The hollow grooves of the second distal end 1222 and the second proximal end 1221 are conducive to improving the connection stability of the inner bracket 122 and the outer bracket 121.

[0056] See also Figure 3 , Figure 5 and Figure 7The second proximal end 1221 of the inner bracket 122 passes through the inner cavity of the first proximal end 1211, and the second distal end 1222 passes through the inner cavity of the first distal end 1212 and is sleeved therein, so that the inner bracket 122 is arranged in the outer bracket 121. At this time, the outer wall of the reinforcement section 1223 of the inner bracket 122 is in contact with the inner wall of the cutting section 1214 of the outer bracket 121, and the reinforcement section 1223 and the cutting section 1214 can be fixedly connected together by a connecting piece.

[0057] Specifically, see Figures 3 to 7 , the cutting section 1214 of the outer bracket 121 is provided with connecting holes 1216 at both ends, and each end has two connecting holes 1216. The corresponding part of the reinforcing section 1223 of the inner bracket 122 is provided with the same number of connecting holes 1225. Through a connecting piece such as a metal wire 123, the inner bracket 122 and the outer bracket 121 are respectively passed through the connecting holes set at the same part to reach the inner wall of the inner bracket 122. At this time, a fixing plate 124 is installed on the inner wall of the reinforcing section 1223 of the inner bracket 122. The metal wire 123 then passes through the two holes of the fixing plate 124 and is welded to the back of the fixing plate 124, so that the inner bracket 122 and the outer bracket 121 are firmly fixed together. Of course, the fixing plate 124 can also be omitted, and the reinforcing section 1223 and the cutting section 1214 are directly fixedly connected together through a connecting piece. The location and number of the connection holes of the inner and outer brackets 121 are not limited thereto. For example, the connection holes may also be located in the middle of the cutting section 1214 of the outer bracket 121 and the reinforcing section 1223 of the inner bracket 122 .

[0058] In other embodiments, one or more rivets may be respectively passed through the cutting section 1214 of the outer bracket 121 and the reinforcing section 1223 of the inner bracket 122 to achieve the fixation of the two. Of course, a sheet of metal may also be used to wrap the cutting section 1214 and the reinforcing section 1223, and then the inner bracket 122 and the outer bracket 121 may be fixedly connected together by welding the metal sheet.

[0059] See also Figure 4 The cutting portion 1215 of the external support 121 is conductive at least on the surface in contact with the valve tissue, and the cutting portion 1215 is electrically connected to an energy generating device 11, so that the cutting portion 1215 can ablate and cut the adhesion parts at the junction of adjacent leaflets. The principle of ablation cutting is: the cutting portion 1215 and the negative electrode plate attached to the outside of the human body form a loop, and the cutting portion 1215 conducts high-frequency current to the adhesion tissue, so that the water molecules in the tissue oscillate rapidly, and the cells are lysed and vaporized, thereby disconnecting the adhesion parts at the junction of adjacent leaflets to achieve cutting. Ablation cutting has a good effect on the expansion of valve stenosis, and can reduce tissue damage and effectively avoid bleeding.

[0060] In this embodiment, the outer bracket 121 and the inner bracket 122 are both insulating parts or covered with insulating coatings, and the cutting part 1215 includes at least one conductive electrode. Specifically, the outer bracket 121 and the inner bracket 122 are insulated as a whole, and the cutting part 1215 is electrically conductive through at least one exposed conductive electrode independent of the outer bracket 121, and the conductive electrode can be fixedly connected to the middle part of the cutting section 1214 of the outer bracket 121 by bonding, crimping, welding, etc. The shape of the conductive electrode includes but is not limited to ring-shaped, sheet-shaped or filament-shaped structures. The cutting part 1215 can be provided with one or more conductive electrodes in the middle part of the cutting section 1214 according to specific performance requirements. It can be understood that when a plurality of conductive electrodes are provided on a single cutting section 1214, preferably, the plurality of conductive electrodes are evenly distributed along the axial direction on the cutting section 1214, and should be symmetrically distributed on the central axis of the cutting section 1214. In this embodiment, the energy generating device 11 is directly electrically connected to the conductive electrode through a wire.

[0061] In other embodiments, the inner bracket 122 is an insulating member or covered with an insulating coating, and the outer bracket 121 is covered with an insulating coating except for the cutting portion 1215, and the cutting portion 1215 is a conductive portion. Specifically, the inner bracket 122 is insulated as a whole, and the cutting portion 1215 of the outer bracket 121 is a conductive portion that can conduct electricity, and other parts are insulated. In this embodiment, the energy generating device 11 can be electrically connected to the first proximal end 1211 through a wire, so that the energy generating device 11 is electrically connected to the cutting portion 1215.

[0062] It can be considered that the insulating material coated on the outer bracket 121 and / or the inner bracket 122 should have a high dielectric strength and should not be easily broken down by voltage, and the insulating coating should have excellent adhesion to the bracket and should not fall off easily under the action of external forces. In addition, the insulating coating should have a uniform thickness and a low friction coefficient. Therefore, the insulating material coated can be a polytetrafluoroethylene coating, a parylene coating, etc. Of course, other coatings with the above properties and applicable can also be used.

[0063] The outer bracket 121 and the inner bracket 122 can be cut from metal tubes including but not limited to nickel-titanium alloys, copper-nickel shape memory alloys, copper-aluminum shape memory alloys, copper-zinc shape memory alloys and the like. In terms of technology, in addition to using the tube for overall cutting, the parts can also be made separately and then welded together. Since the nickel-titanium tube has good metal memory and excellent mechanical properties such as strength, stiffness and elasticity, in this embodiment, preferably, the outer bracket 121 and the inner bracket 122 are both formed by cutting a single nickel-titanium tube and then shaping it. Specifically, a single nickel-titanium tube of a suitable length is used to complete the cutting under a laser cutting machine, and the shaping process is performed after the cutting is completed. After the cutting and shaping, the inner and outer brackets 121 as a whole present a small radial expansion state in the radial direction in the free state.

[0064] See also Figures 11 to 13 The first embodiment of the present invention further discloses a valve expansion system 10, comprising a tube assembly 14 and a valve expander 12 of the aforementioned structure. Figure 3 , Figure 4 and Figure 6 , the first proximal end 1211 is fixedly sleeved on the second proximal end 1221, and the first distal end 1212 is fixedly sleeved on the second distal end 1222. The tube body assembly 14 includes a limiting head 141, an inner tube 142, a first intermediate tube 143 and an outer tube 145. The inner tube 142 is slidably disposed in the first intermediate tube 143, and the first intermediate tube 143 is slidably disposed in the outer tube 145. The inner tube 142, the first intermediate tube 143 and the outer tube 145 of the tube body assembly 14 are axially movably sleeved together in sequence from the inside to the outside, and the proximal end of the limiting head 141 is fixedly connected to the distal end of the inner tube 142.

[0065] See also Fig.12 , the inner tube 142 sequentially passes through the first proximal end 1211, the second proximal end 1221, and the second distal end 1222 and extends out of the first distal end 1212 to be fixedly connected to the limiting head 141, and the first intermediate tube 143 is fixedly connected to the first proximal end 1211. In this way, the radial expansion or contraction of the valve dilator 12 can be controlled by the axial sliding of the inner tube 142 and / or the first intermediate tube 143. The inner tube 142 is slidably arranged in the first intermediate tube 143, so the axial distance between the distal end of the inner tube 142 and the distal end of the first intermediate tube 143 changes with the sliding of the inner tube 142 and / or the first intermediate tube 143, and the axial distance determines the expansion degree or contraction degree of the valve dilator 12.

[0066] Specifically, the first proximal end 1211 and the first distal end 1212 of the outer bracket 121, the second proximal end 1221 and the second distal end 1222 of the inner bracket 122 are all hollow tubular structures, the second proximal end 1221 of the inner bracket 122 passes through the inner cavity of the first proximal end 1211, the second distal end 1222 passes through the inner cavity of the first distal end 1212 and is sleeved inside, the distal end of the inner tube 142 passes through the inner cavities of the first proximal end 1211, the second proximal end 1221 and the second distal end 1222 in sequence and extends out of the first distal end 1212 of the outer bracket 121 and is fixedly connected to the limiting head 141. The fixed connection between the distal end of the inner tube 142 and the limiting head 141, and the fixed connection between the distal end of the first intermediate tube 143 and the first proximal end 1211 can be achieved by welding.

[0067] The limiting head 141 and the first distal end 1212 can be fixedly connected or non-fixedly connected. Fixed connection means that the limiting head 141 and the first distal end 1212 are fixedly connected together by welding, and the first distal end 1212 cannot slide outside the inner tube 142. Non-fixed connection means that the first distal end 1212 of the valve dilator 12 is movably sleeved on the inner tube 142, and the first distal end 1212 can be separated from the limiting head 141 and slide outside the inner tube 142.

[0068] The valve expansion system 10 also includes a handle 15, and the proximal ends of the outer tube 145, the first intermediate tube 143, and the inner tube 142 are all connected to the driving mechanism of the handle 15, and the axial sliding thereof is controlled by the driving mechanism. For example, the driving mechanism can control the outer tube 145 to slide axially to release or retract the valve expander 12; the driving mechanism can control the inner tube 142 to slide axially to achieve relative movement with the first intermediate tube 143, thereby adjusting the radial expansion degree of the valve expander 12. Specifically, after the outer tube 145 releases the valve expander 12, the outer tube 145 and the first intermediate tube 143 are kept stationary, and the inner tube 142 is controlled to move proximally by the driving mechanism of the handle 15, thereby driving the axial compression of the valve expander 12, and at the same time causing the expansion arm 1210 to gradually expand radially, and the cutting portion 1215 gradually ablates the adhesion of the cut valve. Alternatively, the inner tube 142 and the outer tube 145 can be kept fixed, and the driving mechanism of the operating handle 15 can push the first intermediate tube 143 to the distal end, which can also achieve the same effect. The inner tube 142 can be a hollow tubular structure, and the guide wire can pass through the inner cavity of the inner tube 142 to guide the valve expansion system 10 into the human body.

[0069] See also Fig.11 The valve expansion system 10 further includes an embolic protection device 13, which includes an embolic filter 131 and a suction mechanism 132. The tube assembly 14 further includes a second intermediate tube 144, in which the first intermediate tube 143 is slidably disposed, and the second intermediate tube 144 is slidably disposed in the outer tube 145. The embolic filter 131 is fixed to the distal end of the second intermediate tube 144, and the suction mechanism 132 is fixed to the proximal end of the second intermediate tube 144 and communicates with the inner cavity of the second intermediate tube 144.

[0070] It can be understood that the embolic filter 131 is used to intercept the debris that falls off when the valve dilator 12 dilates the narrow calcified valve, preventing it from entering the cerebral blood vessels through the aortic branch and causing harm such as stroke, and the suction mechanism 132 is used to suck out the embolic debris intercepted by the embolic filter 131 from the body, further preventing these debris from circulating with the blood to other parts of the blood vessels and causing blockage. The proximal end of the second intermediate tube 144 can be fixedly connected to the driving mechanism of the handle 15, and its axial movement is controlled by the driving mechanism, so that when the embolic filter 131 is released, its position in the blood vessel can be adjusted, so as to better fix the embolic filter 131.

[0071] Specifically, the distal end of the embolic filter 131 is open, and the proximal end of the embolic filter 131 gradually gathers and is fixedly connected to the distal end of the second intermediate tube 144. When the embolic filter 131 extends from the distal end of the outer tube 145, the embolic filter 131 is in a divergent expansion state from the proximal end to the distal end. The distal end of the embolic filter 131 is close to the surgical site, and the debris generated during the valve expansion process is collected by the open distal end, and then gathered at the proximal end and sucked into the second intermediate tube 144. In this way, a larger debris collection volume is guaranteed, and it is also compatible with the second intermediate tube 144, so that the debris can be directly discharged to the body through the pipeline that intervenes in the human body, and the debris will not enter or flow through other parts, and the safety is greatly improved.

[0072] See also Fig.14 The valve expansion system 10 of this embodiment is used to expand the aortic valve. The embolic filter 131 is set at the position of the ascending aorta and completely fits with the inner wall of the ascending aorta to prevent the embolic debris from continuing to flow to other parts with the blood flow. The outer diameter of the maximum outer diameter of the embolic filter 131 after release should be larger than the inner wall diameter of the aortic blood vessel, so that the embolic filter 131 after release can be squeezed by the inner wall of the blood vessel and fixed in the inner wall of the blood vessel without displacement under the impact of blood flow.

[0073] The embolic filter 131 may include but is not limited to a filter support with a filter membrane attached, a filter net, a filter net with a filter membrane attached, etc. Specifically, the filter support with a filter membrane attached means that the main body of the embolic filter 131 is formed by laser cutting or weaving of a single tube, and a filter membrane is attached to the main body, and the embolic debris is intercepted and filtered through the filter membrane. The tube material can be made of superelastic or shape memory alloy materials such as nickel-titanium alloy, copper-nickel shape memory alloy, etc. The size of the filter hole on the filter membrane should allow blood cells to pass through, while preventing the passage of embolic debris. Preferably, the size of the filter hole of the filter membrane should be greater than 50um. Specifically, the hole size can be set according to the size of the debris that actually needs to be intercepted.

[0074] The filter mesh refers to an embolic filter 131 that is made of a tube through laser cutting or cross-arranged silk threads, preferably woven. For example, a filter mesh woven from nickel-titanium wire or other alloy wires with superelasticity and shape memory, or a filter mesh woven from nylon wire, or a filter mesh woven from a combination of the above nickel-titanium wire and nylon wire. Considering its in vivo development, tantalum wire, platinum wire, tungsten wire and other metal materials with development properties can be inserted at intervals during weaving to improve its in vivo development effect. Preferably, the wire diameter of the above-mentioned braided wire should be between 0.01-0.1mm, more preferably, between 0.01-0.05mm. The braided filter mesh can be a single-layer braided structure or a double-layer braided structure. What is important is that the gaps in the braided mesh can effectively filter embolic debris. Preferably, the gaps should be between 50um-500um. The braided filter mesh with a filter membrane attached is formed by combining the above-mentioned filter membrane and the braided filter mesh, which will not be repeated here.

[0075] The entire system can achieve the release and recovery of the valve dilator 12 and the embolic filter 131 by controlling the axial movement of the outer tube 145 .

[0076] This embodiment uses aortic valve expansion as an example to illustrate the operation of the valve expansion system. Of course, the valve expander system 10 and its operation method can also be applied to the expansion of other valves, such as the mitral valve, tricuspid valve, pulmonary valve, etc.

[0077] S1: Puncture the femoral artery with a puncture device. After the puncture is completed, the valve dilator 12 is delivered to a position close to the aortic valve by using the cooperation of the guide wire and the inner tube 142.

[0078] S2: Under the guidance of external medical imaging equipment such as CT and ultrasound, the driving mechanism of the operating handle 15 allows the limiting head 141 to pass through the narrow aortic valve, so that the limiting head 141 is located on the side of the aortic valve close to the left ventricle.

[0079] S3: The driving mechanism of the operating handle 15 controls the outer tube 145 to slowly move toward the proximal end, so that the valve dilator 12 gradually exposes the outer tube 145. During the release process, external medical imaging equipment such as CT and ultrasound is used to ensure that the cutting section 1214 is accurately inserted into the junction of adjacent valves, and the calcified adhesion is located on the cutting portion 1215 of the cutting section 1214. Then, the outer tube 145 continues to be moved toward the proximal end to completely release the valve dilator 12.

[0080] S4: After the valve dilator 12 is completely released, the outer tube 145 is continuously moved proximally to gradually release the embolic filter 131, which is pressed against the inner wall of the blood vessel. Under the guidance of the external medical imaging device, the embolic filter 131 is placed in the correct position. If the release position is not ideal, the second intermediate tube 144 can be finely adjusted axially by the driving mechanism of the handle 15 to fix the embolic filter 131 to the correct position in the blood vessel.

[0081] S5: When the valve dilator 12 and the embolic filter 131 are completely released and correctly positioned, the energy generating device 11 is started, powered on, and the ablation cutting of the stenotic valve is started. The suction mechanism 132 should be started in advance before starting the energy generating device 11.

[0082] S6: While the energy generating device 11 is working, the driving mechanism of the operating handle 15 controls the inner tube 142 to gradually move toward the proximal end, thereby driving the valve dilator 12 to expand radially, and the bonded stenotic valve is cut open by the dual effects of the radio frequency energy of the energy generating device 11 and the mechanical expansion force of the radial expansion of the valve dilator 12. While cutting and expanding, the embolic filter 131 can effectively intercept and filter out the embolic debris dropped during the operation, and suck it out of the body through the suction mechanism 132.

[0083] S7: When the aortic valve expansion reaches the desired effect, the energy generating device 11 is turned off, the driving mechanism of the operating handle 15 restores the valve expander 12 to the state before expansion, and then the outer tube 145 is moved axially toward the distal end, and the embolic filter 131 and the valve expander 12 are sequentially recovered into the outer tube 145. The system is then withdrawn from the body.

[0084] Embodiment 2

[0085] See also Fig.15 The difference between this embodiment and the first embodiment lies in the structure of the embolic filter 13. In this embodiment, according to the anatomical structure of the ascending aorta, such as the geometric shape of the blood vessel, the curvature of the blood vessel, etc., a fixing position 1311 for contacting with the inner wall of the blood vessel is provided at the distal end of the embolic filter 131, and the fixing position 1311 is recessed inward along the radial direction of the valve dilator 12. The setting of the fixing position 1311 enables the embolic filter 131 to better adapt to and cooperate with the anatomical structure of the aortic vessel in structure, and the embolic filter 131 is fixed in the position of the ascending aorta through this good structural coordination, so as to maintain the stability of the position under the impact of blood flow.

[0086] Embodiment 3

[0087] See also Fig.16The difference between this embodiment and the first embodiment is that the location of the embolic filter 131 in the body is changed from the ascending aorta to the location of the aortic branch.

[0088] In this embodiment, the overall structure of the embolic filter 131 is the same as that described in the first embodiment, and will not be described in detail here. In this embodiment, the embolic filter 131 is located at the aortic arch, and its outer diameter should be slightly larger than the diameter of the inner wall of the aortic arch blood vessel, so that the embolic filter 131 can effectively fit the inner wall of the aortic arch blood vessel. The axial length of the embolic filter 131 should be greater than the farthest distance between the openings of the left subclavian artery and the brachiocephalic trunk, so as to protect embolic debris from entering the aortic arch branch blood vessels, especially preventing it from entering the common carotid artery branch.

[0089] Placing the embolic filter 131 at the aortic arch can avoid hindering and interfering with the blood flow pumped out from the left atrium and reduce the occurrence of vortexes and the like.

[0090] Embodiment 4

[0091] See also Figure 17-19 The difference between this embodiment and the second embodiment lies in the structure of the embolic filter 13. The embolic filter 131 includes a sheet structure, which is made of a shape memory material. In a natural state, the thickness of the middle part of the sheet structure is greater than the thickness of the two ends, and the middle part of the sheet structure is arched. It can be understood that since the middle part of the sheet structure faces the opening of the blood vessel, the middle part is relatively thick and the arch fits the opening and closing of the blood vessel, the effect of intercepting embolic debris is better.

[0092] Specifically, the embolic filter 13 in this embodiment is a spindle-shaped sheet structure, and the curvature of the side profile of the embolic filter 13 is adapted to the vascular curvature of the aortic arch branch segment. When the embolic filter 13 is released, it should fit well to the aortic arch branch segment blood vessel and completely cover the three branch blood vessel openings to prevent embolic debris from entering the branch blood vessel.

[0093] Embodiment 5

[0094] The difference between this embodiment and the first embodiment is that the valve expansion system 10 further includes at least one pressure sensor, and the pressure sensor is disposed on the valve expander 12 and / or the embolic filter 131 .

[0095] Specifically, one or more pressure sensors are added to the valve dilator 12 and / or the embolic filter 131, and the function of measuring blood flow pressure is integrated on the energy generating device 11, so that the real-time blood flow pressure value is dynamically and continuously displayed on the energy generating device 11 in the form of a curve-assisted numerical value, so that the doctor can judge the real-time blood flow pressure during the operation.

[0096] For patients with aortic valve stenosis, the small valve opening causes obstruction of blood flow in the left ventricular outflow tract, faster blood flow, and increased pressure. Therefore, in minimally invasive interventional treatment of aortic valve stenosis, the pressure difference before and after the operation becomes an effective indicator for judging the treatment effect. In current technology, the commonly used pressure difference measurement method is to use the Doppler effect of color Doppler ultrasound to collect the high-speed blood flow spectrum of the left ventricular outflow tract before and after the operation to analyze the corresponding pressure value, and then compare the changes in the pressure value before and after the operation to judge the effect of the operation. The ultrasonic measurement method cannot display the blood pressure value during the operation in real time. It can only rely on the doctor's judgment to statically save the blood flow pressure value at a certain moment and make a comparison. This inspection method has a great relationship with the doctor's subjective judgment and operation level during the operation.

[0097] This embodiment adopts a pressure sensor to measure blood flow pressure. The external device can display the blood flow pressure curve in real time. The doctor can use this curve to determine whether the expansion of the valve has reached the desired state. It is simpler and the results are more intuitive and accurate, which reduces the difficulty of the doctor's operation and improves the efficiency of the operation.

Claims

1. A multi-stent valve expander, characterized in that: include: An expandable external stent, comprising a first distal end and a first proximal end opposite to each other, and at least two expansion arms connected between the first distal end and the first proximal end, wherein the at least two expansion arms are spaced apart along the circumference, and at least one of the expansion arms is provided with a cutting portion on a side away from the other expansion arms; and At least one expandable inner support is arranged in the outer support, and the inner support includes a second proximal end and a second distal end relative to each other, and at least one reinforcement arm connected between the second proximal end and the second distal end, the reinforcement arm at least partially fits the expansion arm and is fixedly connected, the second proximal end is fixedly connected to the first proximal end, and the second distal end is fixedly connected to the first distal end.

2. The valve dilator according to claim 1, characterized in that: The expansion arm includes a cutting segment and two first supporting segments respectively arranged at both ends of the cutting segment, wherein the other end of one of the first supporting segments is connected to the first proximal end, and the other end of the other first supporting segment is connected to the first distal end, and the cutting part is arranged in the cutting segment.

3. The valve dilator according to claim 2, characterized in that: Each of the first support segments includes two support rods, one end of the two support rods merges with and is fixedly connected to one end of the cutting segment, and the other ends of the two support rods merge with and are fixedly connected to the first proximal end or the first distal end.

4. The valve dilator according to claim 2, characterized in that: The cutting section is substantially parallel to the central axis of the outer support.

5. The valve dilator according to claim 2, characterized in that: The reinforcing arm includes a reinforcing section and two second supporting sections respectively arranged at both ends of the reinforcing section, wherein the other end of one of the second supporting sections is connected to the second proximal end, and the other end of the other second supporting section is connected to the second distal end, and the reinforcing section is fixedly connected to the cutting section.

6. The valve dilator according to claim 5, characterized in that: The length of the reinforcement section is less than or equal to the length of the cutting section, and the reinforcement section is attached to and fixedly connected with at least a portion of the cutting section.

7. The valve dilator according to claim 1, characterized in that: The first distal end and the first proximal end are hollow tubular structures, and hollow grooves are provided in the circumference of the first distal end and the first proximal end; and / or, The second distal end and the second proximal end are both hollow tubular structures, and hollow grooves are arranged around the circumference of the second distal end and the second proximal end.

8. The valve dilator according to claim 1, characterized in that: The outer bracket and the inner bracket are both insulating parts or covered with insulating coatings, and the cutting part includes at least one conductive electrode.

9. The valve dilator according to claim 1, characterized in that: The inner bracket is an insulating member or is covered with an insulating coating, and the outer bracket is covered with an insulating coating except for the cutting portion, and the cutting portion is a conductive portion.

10. A valve expansion system, characterized in that: It includes a tube body assembly and the valve dilator according to any one of claims 1 to 9, the first proximal end is fixedly sleeved on the second proximal end, the first distal end is fixedly sleeved on the second distal end, the tube body assembly includes a limiting head, an inner tube, a first intermediate tube and an outer tube, the inner tube is slidably arranged in the first intermediate tube, the first intermediate tube is slidably arranged in the outer tube, the inner tube passes through the first proximal end, the second proximal end, the second distal end in sequence and extends out of the first distal end to be fixedly connected to the limiting head, and the first intermediate tube is fixedly connected to the first proximal end.

11. The valve expansion system according to claim 10, characterized in that: The valve expansion system also includes an embolic protection device, which includes an embolic filter and a suction mechanism. The tube body assembly also includes a second intermediate tube, the first intermediate tube is slidably disposed in the second intermediate tube and the second intermediate tube is slidably disposed in the outer tube, the embolic filter is fixed to the distal end of the second intermediate tube, and the suction mechanism is fixed to the proximal end of the second intermediate tube and communicates with the inner cavity of the second intermediate tube.

12. The valve expansion system according to claim 11, characterized in that: The distal end of the embolic filter is open, the proximal end of the embolic filter gradually gathers and is fixedly connected to the distal end of the second intermediate tube, and when the embolic filter extends from the distal end of the outer tube, the embolic filter is in a divergent expansion state from the proximal end to the distal end.

13. The valve expansion system according to claim 12, characterized in that: The distal end of the embolic filter is provided with a fixing position for abutting against the inner wall of a blood vessel, and the fixing position is recessed inwardly along the radial direction of the valve dilator.

14. The valve expansion system according to claim 11, characterized in that: The embolic filter comprises a sheet-like structure, the sheet-like structure is made of a shape memory material, the thickness of the middle portion of the sheet-like structure is greater than the thickness of both ends, and the middle portion of the sheet-like structure is arched.

15. The valve expansion system according to claim 11, characterized in that: The valve expansion system further comprises at least one pressure sensor, which is disposed on the valve expander and / or the embolic filter.

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