CN114681126A

CN114681126A - Multi-stent valve dilator and valve dilation system

Info

Publication number: CN114681126A
Application number: CN202011585270.5A
Authority: CN
Inventors: 张庭超; 丘信炯; 王柏栋
Original assignee: Hangzhou Valgen Medtech Co Ltd
Current assignee: Hangzhou Valgen Medtech Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2022-07-01

Abstract

The invention provides a multi-stent valve dilator and a valve dilating system. The valve dilator includes an expandable outer stent and at least one expandable inner stent disposed within the outer stent. The external bolster includes opposite first distal and proximal ends, and at least two expansion arms connected between the first distal and proximal ends. At least one of the expansion arms is provided with a cutting portion on a side facing away from the remaining expansion arms. The inner stent includes opposite second proximal and distal ends and at least one reinforcement arm connected between the second proximal and distal ends. The reinforcing arm at least partially abuts against the expansion arm and is fixedly connected with the expansion arm. The second near end is fixedly connected with the first near end, and the second far end is fixedly connected with the first far end. According to the valve dilator, the outer support and the inner support jointly support the dilating arms, the dilating arms are less prone to deformation, the condition that the dilating arms collapse in the dilating process of the outer support can be prevented, valve damage is reduced, and the success rate of surgery is improved.

Description

Multi-stent valve dilator and valve dilation system

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to a multi-stent valve dilator and a valve dilating system.

Background

Valvular stenosis, such as aortic valve stenosis, is a common valvular disease. Aortic stenosis is mainly caused by sequelae of rheumatic fever, congenital aortic valve structural abnormality or senile aortic valve calcification, can cause insufficient blood supply to various organs of the body on one hand, and can cause insufficient oxygen supply to the heart due to relative reduction of coronary blood flow on the other hand, and finally can cause complications such as arrhythmia, pulmonary hypertension, coronary heart disease, cardiac insufficiency and the like.

Aortic stenosis is treated in the prior art by a radially expandable structure that is variable between a collapsed position and an expanded position. The expandable structure is formed from a plurality of expansion arms, each of which includes a proximal section, a distal section, and an intermediate section between the proximal and distal sections, and is operable to radially expand or collapse the expandable structure to provide ablative cutting of valve adhesions. However, since the middle section of the expansion arm has support points only near its proximal and distal ends, the rest is in a suspended state. The middle is suspended, and the structures supported by the two ends can be constructed into a simple beam model with a rectangular cross section on the aspect of engineering mechanics. The middle section, which acts as a beam, is subject to forces from the valve/tissue during operation in practical use. Referring to fig. 1, in the model, the two ends of the beam are respectively a point a and a point B, and are subjected to a supporting force F_AAnd F_BThe central part of the beam is subjected to a concentrated load F at the C point, and if the length of the central part is l, the central part of the beam is subjected to the maximum bending moment M_maxThe middle section is susceptible to deformation and collapse at F × l/4. Moreover, for the valve which swings ceaselessly, the cutting part of the expansion arm with insufficient supporting force is difficult to keep always aligned with the cutting position of the valve in flowing blood, which easily causes damage to the valve during ablation cutting and prolongs the operation time.

Disclosure of Invention

It is a primary object of the present invention to overcome the above-mentioned disadvantages of the prior art in which the arms of a radially expandable structure are susceptible to deformation and collapse, and to provide a multi-stent valve dilator comprising:

an expandable external stent comprising opposite first distal and proximal ends, and at least two expansion arms connected between said first distal and proximal ends, at least one of said expansion arms being provided with a cutting portion on a side facing away from the remaining expansion arms; and the number of the first and second groups,

at least one expandable inner stent disposed within said outer stent, said inner stent comprising opposed second proximal and second distal ends, and at least one reinforcing arm connected between said second proximal end and said second distal end, said reinforcing arm at least partially conforming to and fixedly connecting said expansion arm, said second proximal end fixedly connected to said first proximal end, and said second distal end fixedly connected to said first distal end.

The invention also provides a valve expansion system, which comprises a tube body assembly and the valve expander with the structure, wherein the first near end is fixedly sleeved on the second near end, the first far end is fixedly sleeved on the second far end, the tube body assembly comprises a limiting head, an inner tube, a first middle tube and an outer tube, the inner tube is slidably arranged in the first middle tube, the first middle tube is slidably arranged in the outer tube, the inner tube sequentially penetrates through the first near end, the second near end and the second far end and extends out of the first far end to be fixedly connected with the limiting head, and the first middle tube is fixedly connected with the first near end.

The invention relates to a multi-stent valve expander and a valve expanding system, which utilize a cutting part of an expanding arm to gradually cut and continuously expand the valve adhesion part, an outer stent and an inner stent together provide support for the expanding arm, a reinforcing arm of the inner stent is fixed with the expanding arm, so that the supporting force can be increased for the outer stent in the process of cutting and expanding the valve, a stressed fulcrum can be additionally arranged on the expanding arm to support the expanding arm, and the expanding arm has the supporting force under the action of the same concentrated load and is less prone to deformation, thereby preventing the condition that the expanding arm collapses due to the insufficient valve resistance and self supporting force of the outer stent in the expanding process, effectively improving the stability of the expanding arm, reducing the valve damage and improving the success rate of the operation.

Drawings

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.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a force model diagram of an expansion arm of a prior art valve dilator.

Fig. 2 is a schematic structural diagram of the valve dilator according to the first embodiment.

Fig. 3 is an exploded view of the valve dilator of the first embodiment.

Fig. 4 is a schematic structural diagram of an external stent according to the first embodiment.

Fig. 5 is a side view of the external bolster of the first embodiment.

Fig. 6 is a schematic structural diagram of the inner bracket according to the first embodiment.

Fig. 7 is a front view of the inner frame according to the first embodiment.

Fig. 8 is another structural schematic view of the valve dilator of the first embodiment.

Fig. 9 is another elevation view of the valve dilator of the first embodiment.

Fig. 10 is a force model diagram of the dilating arms of the valve dilator of the first embodiment.

Fig. 11 is a schematic structural view of the valve-expanding system of the first embodiment.

Fig. 12 is a partially enlarged view of a portion a in fig. 11.

Fig. 13 is an exploded view of portion a of fig. 11.

Fig. 14 is a schematic view of the working scene of the valve expanding system according to the first embodiment.

Fig. 15 is a schematic view of the working scene of the valve expanding system of the second embodiment.

Fig. 16 is a schematic view of the working scene of the valve expanding system of the third embodiment.

Fig. 17 is a schematic view of an operating scenario of the valve expanding system according to the fourth embodiment.

FIG. 18 is a top view of an embolic filter according to the fourth embodiment.

FIG. 19 is a side view of an embolic filter of a fourth embodiment.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

It should be understood that the directions and positional relationships indicated by the terms "front", "back", "upper", "lower", "left", "right", "longitudinal", "lateral", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc., are constructed and operated in specific directions based on the directions and positional relationships in the drawings, and are only for convenience of describing the present invention, but do not indicate that the device or element referred to must have a specific direction, and thus, should not be construed as limiting the present invention.

It is also noted that, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," "disposed," and the like are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or intervening elements may also be present. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is still to be noted 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; axial refers to a direction parallel to the line joining the distal and proximal centers of the instrument or component, radial refers to a direction perpendicular to the axial direction, and circumferential refers to a direction around the axial direction.

In order to overcome the defect that the expansion arms of the valve expander are easy to collapse in the cutting process in the prior art, the invention discloses a multi-support valve expander and a valve expanding system. The invention is described below with reference to specific embodiments in conjunction with the accompanying drawings.

Example one

Referring to fig. 2-9, the present invention provides a multi-stent valve dilator 12 including an expandable outer stent 121 and at least one expandable inner stent 122. Outer stent 121 includes opposing first distal end 1212 and first proximal end 1211, and at least two expansion arms 1210 connected between first distal end 1212 and first proximal end 1211. At least one expansion arm 1210 is provided with a cut 1215 on the side facing away from the remaining expansion arms 1210. Inner stent 122 is disposed within outer stent 121, and inner stent 122 includes opposing second proximal end 1221 and second distal end 1222, and at least one reinforcement arm 1220 connected between second proximal end 1221 and second distal end 1222. The reinforcement arm 1220 is at least partially received and fixedly attached to the expansion arm 1210, the second proximal end 1221 is fixedly attached to the first proximal end 1211, and the second distal end 1222 is fixedly attached to the first distal end 1212.

According to the technical scheme of the embodiment, the cutting part 1215 of the expansion arm 1210 is used for gradually cutting and continuously expanding the valve adhesion part, the outer support 121 and the inner support 122 jointly support the expansion arm 1210, the reinforcing arm 1220 of the inner support 122 is fixed with the expansion arm 1210, so that supporting force can be increased for the outer support 121 in the process of cutting and expanding the valve, a stressed fulcrum can be additionally arranged on the expansion arm 1210 to support the expansion arm 1210, and under the action of the same concentrated load, the expansion arm 1210 has supporting force and is less prone to deformation, so that the situation that the expansion arm 1210 is collapsed due to the fact that the outer support 121 is subjected to valve resistance and insufficient self-supporting force in the expansion process is prevented, the stability of the expansion arm 1210 is effectively improved, valve damage is reduced, and the success rate of the operation is improved.

The valve dilator 12 is configured as a multi-stent structure, and aims to increase a supporting force for the outer stent 121 in the process of valve dilation, so as to prevent the outer stent 121 from being incapable of supporting and continuously dilating the valve due to the fact that the supporting force is weak and the external resistance is large in the process of dilation, and causing stent collapse. Referring to fig. 10, two ends of the expansion arm 1210 are respectively connected to the first proximal end 1211 and the first distal end 1212, i.e. the two ends of the beam are supported by the supporting force F at the points a and B_AAnd F_BWhen the inner support 122 is present, i.e. at point C, an upward supporting force F is added to the beam_CChanging the model of simply supported beam into statically indeterminate beam, i.e. adding additional constraints F_CThereby improving the stability of the beam.

The valve dilator 12 in this embodiment is a double stent structure, comprising an outer stent 121 and an inner stent 122 fixed coaxially inside it. It is of course conceivable that the present invention is not limited to a double stent structure, but a triple stent structure is equally applicable to the present invention, i.e., the valve dilator 12 includes an outer stent 121 and two inner stents 122 coaxially fixed inside thereof. Of course, the number of the inner brackets 122 may be three, or even more than three.

Considering the anatomical structure of the valve, the number of expansion arms 1210 of the outer stent 121 may be less than or equal to the number of leaflets constituting the valve, for example, two leaflets of the mitral valve, three leaflets of the aortic valve, the tricuspid valve, the pulmonary valve, and considering the inner stent 122 disposed inside the outer stent 121, the number of expansion arms 1210 is at least two. The expansion arms 1210 can be radially expanded into calcified junctions of adjacent leaflets and the adhesion site at the junction of adjacent leaflets can be cut, e.g., mechanically or ablatively, by the cutting section 1215.

The expansion arms 1210 of the outer stent 121 may be circumferentially spaced apart, preferably uniformly circumferentially arranged. Of course, the expansion arms 1210 may also be non-uniformly circumferentially arranged. The two and three expansion arms 1210 are configured for use in bilobe and trilobe stenosis, respectively. Because the cutting parts 1215 of the two or three expansion arms 1210 do not enclose a cylindrical shape similar to the middle part of the balloon around the circumferential direction, the cutting parts 1215 of the valve dilator 12 can be accurately clamped into the boundary gaps of two adjacent valve leaflets to cut calcified adhesion parts at the boundary, thereby achieving the purpose of expanding the area of the valve orifice and relieving a series of adverse symptoms caused by stenosis. Notably, the number of expansion arms 1210 is undesirably large, preventing all of the expansion arms 1210 from circumferentially contacting the leaflets, like a balloon, and failing to enter the interface gaps between adjacent leaflets.

In view of the actual radial dimension of the orifice of the body, the maximum radial dimension of the outer diameter of the outer support 121 in its natural state should preferably be between 10-25 mm. Considering that the outer stent 121 expands radially when subjected to an axial compressive force, it is more preferably between 15-20 mm.

The number of the arms 1220 of the inner stent 122 may be one, with the arms 1220 at least partially engaging one of the expansion arms 1210 and being fixedly attached. Preferably, in order to ensure the stability of the whole external frame 121, the number of the reinforcing arms 1220 is the same as that of the expansion arms 1210, and the reinforcing arms 1220 are uniformly arranged at intervals in the circumferential direction like the expansion arms 1210 and are fixedly connected in a one-to-one correspondence manner.

In the natural state of the inner stent 122, the maximum radial dimension of the outer diameter of the inner stent 122 should be equal to the maximum radial dimension of the inner diameter of the outer stent 121 in the natural state, so as to ensure that when the inner stent 122 is sleeved in the outer stent 121 in the natural state, the outer walls of the reinforcing arms 1220 of the inner stent 122 can be just attached to the inner walls of the expansion arms 1210 of the outer stent 121, so as to better fixedly connect the two stents together. Referring to fig. 2 and 3, the length of the expansion arm 1210 is slightly greater than that of the reinforcement arm 1220, so as to ensure that the fit length of the expansion arm 1210 is greater and the expansion arm 1210 can be supported more strongly. Referring to fig. 8 and 9, in some embodiments, the engagement length of the reinforcing arm 1220 and the expansion arm 1210 is smaller, and the engagement fixing portion is disposed at the middle of the reinforcing arm 1220 to ensure the uniform support of the expansion arm 1210 by the reinforcing arm 1220.

Referring to fig. 4 and 5, the expansion arm 1210 includes a cutting segment 1214 and two first support segments 1213 disposed at two 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, the other end of the other of the first support segments 1213 is connected to the first distal end 1212, and the cutting portion 1215 is provided in the cutting segment 1214. It will be appreciated that the first support section 1213 adjacent one side of the first proximal end 1211 is connected at one end to the first proximal end 1211 and at the other end to the cutting section 1214. A first support section 1213 adjacent to the side of the first distal end 1212 has one end connected to the first distal end 1212 and one end connected to the cutting section 1214. Thus, the first support section 1213 functions to support both ends of the cutting section 1214. The cutting part 1215 is disposed on the middle cutting section 1214, so that the cutting part 1215 can be aligned with the adhesion part on the boundary of the adjacent valve leaflets for cutting.

When the expansion arms 1210 are arranged in segments, and the first proximal end 1211 and the first distal end 1212 move relatively in the axial direction, 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 stent 121 (which coincides with the central axis Z of the valve dilator) is changed to adjust the radial distance between the cutting segment 1214 and the central axis X. Specifically, when the proximal end 1211 is axially close to the distal end 1212, the axial distance between the proximal end 1211 and the distal end 1212 decreases, the radial distance between the end of each first support section 1213 connecting the corresponding cutting section 1214 and the central axis X increases, and the radial distance between the cutting section 1214 and the central axis X increases, so that the cutting portion 1215 on the cutting section 1214 progressively cuts the adhesion at different radial positions at the boundary of the adjacent valve leaflets to adapt to the physiological anatomical difference of different individual valves (the progressive cutting is performed by keeping a radial distance between the cutting section 1214 and the central axis X for a certain period of time, then slightly increasing the radial distance between the cutting section 1214 and the central axis X, and continuing to perform the cutting, which is repeated). As the first proximal end 1211 is axially spaced apart relative to 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 from the central axis X decreases for each end of the first support segment 1213 connecting the respective cutting segment 1214, such that the radial distance from the central axis X decreases for the cutting segment 1214 to receive the valve dilator 12.

It will be appreciated that the cutting segment 1214 of the expansion arm 1210 is substantially parallel to the central axis X of the outer stent 121, i.e., the cutting segment 1214 is substantially the same distance from the central axis X at any point, with a deviation of less than 0.5 mm. Specifically, when the valve dilator 12 is in a natural state, the first support section 1213 is inclined outwardly with respect to the central axis X of the outer stent 121 at an angle in the range of 30-60 °, and the cutting section 1214 is substantially parallel to the central axis X. When the valve dilator 12 is in the cut state, the outer stent 121 radially expands or contracts, and the cutting segments 1214 may remain substantially parallel to the central axis X due to the adjustment of the radial distance of the cutting segments 1214 from the central axis X by the change of the radial distance of the end of each first support segment 1213 connecting the respective cutting segment 1214 from the central axis X.

In this embodiment, the cutting section 1214 is substantially a straight rod that is parallel to the axial direction. It is of course contemplated that in other embodiments, the rod may be an undulating rod or other form of rod, and that the cutting segment 1214 may simply meet the mechanical requirements used herein to ensure that it does not break during expansion and contraction. In particular, the overall length of the cutting section 1214 should preferably be between 10-30mm, and more preferably between 15-25mm in length in consideration of the height of the leaflet when moving in vivo. The width of the cutting section 1214 should preferably be between 0.8-1.5mm and the wall thickness between 0.3-0.5 mm.

Referring to fig. 4 and 5, each of the first support segments 1213 includes two support bars 12131, one end of two support bars 12131 being joined and fixedly connected to one end of the cutting segment 1214, and the other end of two support bars 12131 being joined and fixedly connected to the first proximal end 1211 or the first distal end 1212. Of course, each first support section 1213 may be a single support bar.

Specifically, the first support section 1213 may be combined by two support bars 12131 that extend radially outward in the axial direction of the outer carrier 121 and eventually meet. One end of the two support bars 12131 forms a first intersection 12132 with the cutting segment 1214 and the other end forms a second intersection 12133 with the first proximal end 1211 or the first distal end 1212. Each strut 12131 has a central portion projecting away from the other strut 12131, the two struts 12131 resemble a diamond, one end of each strut 12131 converges at one end of the cutting segment 1214 to form a first convergence point 12132, and the other end converges at the first proximal end 1211 or the first distal end 1212 to form a second convergence point 12133. The first support section 1213 is a split and gathered structure, which increases the stability of the valve dilator 12, especially when the valve dilator 12 is axially contracted, and greatly reduces the torsion deformation phenomenon that may occur when the valve dilator 12 is axially contracted.

In this embodiment, the first distal end 1212 and the first proximal end 1211 are hollow tubular structures, and hollow grooves are formed in the circumferential directions of the first distal end 1212 and the first proximal end 1211. Specifically, the tube walls of the first distal end 1212 and the first proximal end 1211 are each formed with a spiral groove, a zigzag groove, a mesh groove, or other hollow grooves, and preferably, the hollow grooves are spiral. The hollowed-out grooves can increase the surface roughness of the first proximal end 1211 and the first distal end 1212, and ensure the firmness of connection and the adhesion of the material of the valve dilator 12 when interconnected with the associated structures on the delivery device, thereby enhancing the pull-off resistance.

Referring to fig. 6 and 7, inner support 122 is similar in structure to outer support 121. Inner housing 122 includes a second proximal end 1221, a second distal end 1222, and a reinforcement arm 1220 coupled between second proximal end 1221 and second distal end 1222.

Specifically, the reinforcement arm 1220 includes a reinforcement section 1223 and two second support sections 1224 provided at both ends of the reinforcement section 1223, respectively. The other end of one of the second support sections 1224 is coupled to the second proximal end 1211 and the other end of the other of the second support sections 1224 is coupled to the second distal end 1212.

It is understood that the second support section 1224 of the inner support 122 may be formed by extending and converging two support rods as the first support section 1213 of the outer support 121, and the specific structure thereof is described above, and will not be described herein. Of course, the second support section 1224 may be formed from a single support rod, specifically, a single support rod extending radially outward from the second proximal end 1221 or the second distal end 1222 and finally meeting both ends of the reinforcement section 1223 of the inner support 122. The reinforcing section 1223 is a straight rod parallel to the central axis Y of the inner stent 122 (coinciding with the central axis Z of the valve dilator 12), so that the reinforcing section 1223 is fixedly connected to the cutting section 1214. In order to facilitate the connection between the reinforcing segment 1223 and the cutting segment 1214, the width of the reinforcing segment 1223 should be consistent with the width of the cutting segment 1214, the length of the reinforcing segment 1223 is less than or equal to the length of the cutting segment 1214, and the reinforcing segment 1223 is attached and fixedly connected to at least a portion of the cutting segment 1214.

Referring to fig. 2 and 3, similar to the structure of the outer stent 121, the second proximal end 1221 and the second distal end 1222 of the inner stent 122 are also hollow tubular structures, and the second proximal end 1221 and the second distal end 1222 are circumferentially provided with hollow grooves. 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 and fixed on the second proximal end 1221, and the first distal end 1212 can be sleeved and fixed on the second distal end 1222. The hollowed-out slots of the second distal end 1222 and the second proximal end 1221 are beneficial for improving the stability of the connection between the inner stent 122 and the outer stent 121.

Referring to fig. 3, 5 and 7, the second proximal end 1221 of the inner stent 122 passes through the lumen of the first proximal end 1211, and the second distal end 1222 is sleeved inside the lumen of the first distal end 1212, such that the inner stent 122 is disposed inside the outer stent 121. At this time, the outer wall of the reinforcing segment 1223 of the inner stent 122 is in close contact with the inner wall of the cutting segment 1214 of the outer stent 121, and the reinforcing segment 1223 and the cutting segment 1214 are fixedly connected together by a connector.

Specifically, referring to fig. 3 to 7, both ends of the cutting segment 1214 of the outer bracket 121 are provided with connecting holes 1216, two of each end connecting hole 1216. The reinforcing section 1223 of the inner bracket 122 is provided with the same number of attachment holes 1225 at corresponding locations. A fixing piece 124 is installed on the inner wall of the reinforcing segment 1223 of the inner bracket 122 by passing a connecting member such as a wire 123 through the connecting holes of the inner bracket 122 and the outer bracket 121, which are provided at the same location, to the inner wall of the inner bracket 122, and the wire 123 passes through two holes of the fixing piece 124 and is welded to the back of the fixing piece 124, thereby firmly fixing the inner bracket 122 and the outer bracket 121 together. Of course, the fixing plate 124 may be omitted, and the reinforcing section 1223 and the cutting section 1214 may be directly fixedly connected together by a connecting member. The arrangement position and number of the coupling holes of the inner and outer brackets 121 are not limited to this, and for example, the position of the coupling holes may be arranged in the middle between the cutting section 1214 of the outer bracket 121 and the reinforcing section 1223 of the inner bracket 122.

In other embodiments, the fixation of the cut segment 1214 of the outer stent 121 and the reinforced segment 1223 of the inner stent 122 may be accomplished by one or more rivets passing through both. Of course, the cutting segment 1214 and the reinforcing segment 1223 may be wrapped by a sheet of metal, and the inner bracket 122 and the outer bracket 121 may be fixedly connected by welding the sheet of metal.

Referring to fig. 4, the cutting portion 1215 of the outer frame 121 is electrically conductive at least at the surface where the valve tissue contacts, and the cutting portion 1215 is electrically connected to an energy generating device 11, such that the cutting portion 1215 can ablate and cut the adhesion site at the interface between adjacent leaflets. The principle of ablation cutting is: the cutting part 1215 and a negative plate applied outside the human body form a loop, the cutting part 1215 conducts high-frequency current to the adhesion tissue, so that water molecules in the tissue are rapidly oscillated, cells are cracked and vaporized, and the adhesion part on the boundary of adjacent valve blades is disconnected to realize cutting. The ablation and cutting effect on the expansion of the valvular stenosis is good, the tissue damage can be reduced, and the bleeding can be effectively avoided.

In this embodiment, both the outer support 121 and the inner support 122 are insulators or covered with an insulating coating, and the cut 1215 includes at least one conductive electrode. Specifically, the outer frame 121 and the inner frame 122 are integrally insulated, the cut part 1215 is electrically conducted through at least one exposed conductive electrode independent of the outer frame 121, and the conductive electrode may be fixedly attached to the middle portion of the cut section 1214 of the outer frame 121 by means of bonding, crimping, welding, or the like. The form of the conductive electrode includes, but is not limited to, a ring-shaped, sheet-shaped or filament-shaped structure. The cutting section 1215 may provide one or more conductive electrodes in the middle of the cutting segment 1214, depending on the particular performance requirements. It will be appreciated that when a plurality of conductive electrodes are disposed on a single cutting segment 1214, the plurality of conductive electrodes are preferably uniformly distributed axially across cutting segment 1214 and symmetrically distributed about a central axis of cutting segment 1214. In this embodiment, the energy generating device 11 is directly electrically connected to the conductive electrode through a wire.

In other embodiments, the inner support 122 is an insulator or covered with an insulating coating, the outer support 121 is covered with an insulating coating except for the cut 1215, which is a conductive portion. Specifically, the inner frame 122 is insulated as a whole, the cut 1215 of the outer frame 121 is electrically conductive for the conductive portion, and the other portions are insulated. In this embodiment, the energy generating device 11 may be electrically connected to the first proximal end 1211 through a wire, such that the energy generating device 11 is electrically connected to the cutting portion 1215.

It is considered that the insulating material coated on the outer holder 121 and/or the inner holder 122 should have high insulating strength and should not be easily broken down by voltage, and the adhesion between the insulating coating and the holder should be excellent and should not be easily released by an external force. In addition, the insulating coating should have a uniform thickness and a low coefficient of friction. Thus, the insulating material applied may be a polytetrafluoroethylene coating, parylene coating, or the like, although other suitable coatings having the above properties may also be used.

The outer frame 121 and the inner frame 122 can be cut from a metal tube made of, but not limited to, nitinol, copper-nickel shape memory alloy, copper-aluminum shape memory alloy, copper-zinc shape memory alloy, etc. In the process, the pipe is integrally cut, and each part can be manufactured in a split mode and then welded. Since the nitinol tube has good metal memory and excellent mechanical properties such as strength, rigidity and elasticity, in this embodiment, the outer stent 121 and the inner stent 122 are preferably formed by cutting and shaping a single nitinol tube. Specifically, a single nickel-titanium tube with a proper length is used to complete cutting under a laser cutting machine, shaping is performed after the cutting is completed, and the cut and shaped inner and outer stents 121 integrally present a small-amplitude radial expansion state in a radial direction in a free state.

Referring to fig. 11-13, a valve dilation system 10 is further disclosed in accordance with a first embodiment of the present invention, which includes a tube assembly 14 and a valve dilator 12 of the foregoing construction. Referring to fig. 3, 4 and 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 body assembly 14 includes a confining head 141, an inner tube 142, a first intermediate tube 143, and an outer tube 145. The inner tube 142 is slidably disposed within the first intermediate tube 143, and the first intermediate tube 143 is slidably disposed within the outer tube 145. The inner tube 142, the first middle tube 143 and the outer tube 145 of the tube assembly 14 are sequentially and movably sleeved together along the axial direction from inside to outside, and the proximal end of the limiting head 141 is fixedly connected with the distal end of the inner tube 142.

Referring to fig. 12, the inner tube 142 passes through the first proximal end 1211, the second proximal end 1221, the second distal end 1222, extends out of the first distal end 1212, and is fixedly connected to the limiting head 141, and the first middle tube 143 is fixedly connected to the first proximal end 1211. In this way, radial expansion or contraction of the valve dilator 12 can be controlled by axial sliding of the inner tube 142 and/or the first intermediate tube 143. The inner tube 142 is slidably disposed within the first intermediate tube 143 such that the axial distance between the distal end of the inner tube 142 and the distal end of the first intermediate tube 143, which determines the degree of expansion or contraction of the valve dilator 12, changes as the inner tube 142 and/or the first intermediate tube 143 slide.

Specifically, the first proximal end 1211 and the first distal end 1212 of the outer stent 121, the second proximal end 1221 and the second distal end 1222 of the inner stent 122 are both hollow tubular structures, the second proximal end 1221 of the inner stent 122 passes through the tube lumen of the first proximal end 1211, the second distal end 1222 is sleeved inside the tube lumen of the first distal end 1212, and the distal end of the inner tube 142 passes through the tube lumens 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 stent 121 to be fixedly connected with the limiting head 141. The fixed connection of the distal end of the inner tube 142 to the delimiting head 141 and the fixed connection of the distal end of the first intermediate tube 143 to the first proximal end 1211 can be realized by means of welding.

The confining head 141 may be fixedly connected or non-fixedly connected to the first distal end 1212. The fixed connection finger limiting head 141 and the first distal end 1212 are fixedly connected together in a welding manner, and the first distal end 1212 cannot slide outside the inner tube 142. The first distal end 1212 of the non-fixed connection finger valve dilator 12 is movably sleeved on the inner tube 142, and the first distal end 1212 can slide outside the inner tube 142 away from the retaining head 141.

Valve-expanding system 10 further includes a handle 15, and the proximal ends of outer tube 145, first intermediate tube 143, and inner tube 142 are all connected to a driving mechanism of handle 15, and are controlled to slide axially by the driving mechanism. For example, the drive mechanism may control outer tube 145 to slide axially to release or retract valve dilator 12; the driving mechanism can control the inner tube 142 to slide axially to realize relative movement with the first middle tube 143, so as to adjust the expansion degree of the valve expander 12 along the radial direction. Specifically, after the outer tube 145 releases the valve dilator 12, the outer tube 145 is kept stationary with the first intermediate tube 143, and the inner tube 142 is controlled to move proximally by the driving mechanism of the handle 15, thereby compressing the valve dilator 12 in the axial direction and simultaneously gradually expanding the expansion arms 1210 in the radial direction, and the cutting portion 1215 gradually ablates and cuts the valve adhesion. Alternatively, the same effect can be achieved by holding the inner tube 142 and the outer tube 145 stationary and pushing the first intermediate tube 143 distally by the drive mechanism of the operating handle 15. The inner tube 142 may be a hollow, tubular structure and a guidewire may be passed through the lumen of the inner tube 142 to guide the valve expansion system 10 into the body.

Referring to fig. 11, the valve dilation system 10 further includes an embolic protection device 13, the embolic protection device 13 including an embolic filter 131 and a suction mechanism 132. The body assembly 14 further includes a second intermediate tube 144, the first intermediate tube 143 being slidably disposed within the second intermediate tube 144 and the second intermediate tube 144 being slidably disposed within the outer tube 145. The embolic filter 131 is secured to the distal end of the second intermediate tube 144 and the suction mechanism 132 is secured to the proximal end of the second intermediate tube 144 and in fluid communication with the lumen of the second intermediate tube 144.

It will be appreciated that the embolic filter 131 is used to intercept sloughed debris from entering the cerebral vessels through the aortic branch to cause stroke and the like when the valve dilator 12 dilates the stenotic calcified valve, and the suction mechanism 132 is used to suck the embolic debris intercepted by the embolic filter 131 out of the body, further preventing the debris from being blocked by the blood vessels flowing to other parts along with the blood. The proximal end of the second intermediate tube 144 may be fixedly connected to a drive mechanism of the handle 15, the axial movement of which is controlled by the drive mechanism to adjust the position of the embolic filter 131 within the vessel when the embolic filter 131 is released, thereby better securing the embolic filter 131.

Specifically, the distal end of the embolic filter 131 is open and the proximal end of the embolic filter 131 is gradually gathered and fixedly attached to the distal end of the second intermediate tube 144. When the embolic filter 131 is extended from the distal end of the outer tube 145, the embolic filter 131 is in a diverging expanded state from the proximal end to the distal end. The distal end of the embolic filter 131 is proximal to the surgical site and debris generated during the valve expansion process is collected by the open distal end and collected proximally and sucked into the second intermediate tube 144. Thus, the collection volume of larger debris is ensured, and the second middle pipe 144 is matched with the debris, so that the debris can be directly discharged to the outside of the body through a pipeline intervening in the human body, the debris cannot enter or flow through other parts, and the safety is greatly improved.

Referring to fig. 14, the valve dilation system 10 of the present embodiment is used to dilate an aortic valve, and the embolic filter 131 is disposed in the ascending aorta and fully engages the inner wall of the ascending aorta to prevent sloughed embolic debris from continuing to flow with the blood to other locations. The outer diameter of the largest outer diameter of the released embolic filter 131 should be larger than the diameter of the inner wall of the aortic vessel so that the released embolic filter 131 can be pressed by the inner wall of the vessel and fixed in the inner wall of the vessel without being displaced by the impact of blood flow.

The embolic filter 131 may be, but is not limited to, a filter support to which a filter membrane is attached, a filter mesh to which a filter membrane is attached, or the like. Specifically, the filtering stent with the filtering membrane attached thereto means that the main body of the embolic filter 131 is formed by laser cutting or weaving a single pipe, the filtering membrane is attached to the main body, and the embolic debris is intercepted and filtered by the filtering membrane. The tube material can be made of super-elastic or shape memory alloy materials such as nickel-titanium alloy, copper-nickel shape memory alloy and the like. The filter pores of the filter membrane are sized to allow passage of blood cells while preventing passage of embolic debris. Preferably, the size of the filtering holes of the filtering membrane should be larger than 50um, and in particular, the size of the holes can be set according to the size of the fragments intercepted in actual needs.

The filtering net is formed by weaving the embolic filter 131 by laser cutting or cross arrangement of threads, preferably weaving. For example, the filter net may be woven from a nickel-titanium wire or another alloy wire having superelasticity and shape memory properties, may be woven from a nylon wire, or may be woven from a combination of the nickel-titanium wire and the nylon wire. In consideration of the in vivo developability, a metal material having developability, such as a tantalum wire, a platinum wire, or a tungsten wire, may be inserted at intervals during weaving to improve the in vivo developability. Preferably, the filament diameter of the above-mentioned braided filaments should be between 0.01-0.1mm, more preferably between 0.01-0.05 mm. The woven filter screen can be of a single-layer woven structure or a double-layer woven structure, and importantly, gaps of the woven filter screen can effectively filter embolic debris, and preferably, the gaps are between 50 and 500 microns. The woven filter net with the attached filter membrane is formed by combining the filter membrane and the woven filter net, and the details are not repeated herein.

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

The present embodiment describes the operation of the valve dilation system by taking aortic valve dilation as an example, but the valve dilation system 10 and the operation method thereof can also be applied to dilation of other valves, such as mitral valve, tricuspid valve, pulmonary valve, and the like.

S1: the puncture device punctures the femoral artery, and after the puncture is completed, the valve dilator 12 is sent to a position close to the aortic valve by the matching of the guide wire and the inner tube 142.

S2: under the guidance of external medical imaging equipment such as CT, ultrasound, etc., the driving mechanism of the handle 15 is operated to make the limiting head 141 pass through the narrow aortic valve, so that the limiting head 141 is positioned at the side of the aortic valve close to the left ventricle.

S3: the driving mechanism of the operating handle 15 controls the outer tube 145 to move slowly and proximally, so that the valve dilator 12 gradually exposes out of the outer tube 145, the cutting section 1214 is ensured to be accurately clamped at the junction of the adjacent valves by an external medical imaging device such as CT, ultrasound and the like during the releasing process, and the calcified adhesion part is positioned on the cutting part 1215 of the cutting section 1214. Subsequent continued proximal movement of outer tube 145 causes valve dilator 12 to be fully released.

S4: after the valve dilator 12 is fully released, the outer tube 145 is moved further proximally to gradually release the embolic filter 131, and the embolic filter 131 abuts against the inner wall of the blood vessel, so that the embolic filter 131 is in the correct position under the guidance of the external medical imaging device. If the release position is less than ideal, the second intermediate tube 144 may be fine-tuned axially by the drive mechanism of the handle 15 to secure the embolic filter 131 in the correct position in the blood vessel.

S5: when the valve dilator 12 and the embolic filter 131 are both fully released and properly positioned, the energy generating device 11 is activated and the ablation cut of the stenotic valve is initiated. The pumping mechanism 132 should be activated in advance before the energy generating means 11 is activated.

S6: when the energy generating device 11 works, the driving mechanism of the operating handle 15 controls the inner tube 142 to gradually move towards the proximal end, so as to drive the valve dilator 12 to perform radial expansion, and the bonded stenotic valve is cut through the dual functions 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 the dilation, the embolic filter 131 effectively intercepts and filters out intraoperatively dropped embolic debris and is aspirated out of the body through the suction mechanism 132.

S7: when the desired effect on the expansion of the aortic valve is achieved, the energy generating device 11 is turned off, the actuating mechanism of the operating handle 15 returns the valve expander 12 to the pre-expanded state, and the outer tube 145 is then moved axially distally, which in turn retracts the embolic filter 131 and the valve expander 12 into the outer tube 145. The system was then withdrawn outside the body.

Example two

Referring to fig. 15, the difference between the first embodiment and the second embodiment is the structure of the embolic filter 13. In this embodiment, according to the anatomy of the ascending aorta: specifically, the distal end of the embolic filter 131 is provided with a fixation site 1311 for abutting against the inner wall of the blood vessel, such as the geometry of the blood vessel, the curvature of the blood vessel, etc., and the fixation site 1311 is recessed inward in the radial direction of the valve dilator 12. The positioning of the fixation site 1311 allows the embolic filter 131 to structurally better conform to the anatomy of the aortic vessel, by providing a structurally sound fit to hold the embolic filter 131 in place in the ascending aorta, thereby maintaining positional stability under the impact of blood flow.

EXAMPLE III

Referring to fig. 16, the difference between the first embodiment and the second embodiment is that the position of the embolic filter 131 in the body is changed from the position of the ascending aorta to the position of the aortic branch.

In this embodiment, the overall structure of the embolic filter 131 is the same as that described in the first embodiment, and is not described herein again. In this embodiment, the embolic filter 131 is located at the aortic arch, and the outer diameter thereof 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 adhere to the inner wall of the aortic arch blood vessel. The axial length of the embolic filter 131 should be greater than the farthest distance of the left subclavian artery and brachiocephalic artery openings to protect embolic debris from entering the aortic arch branch vessel, particularly from the common carotid artery branch.

By placing the embolic filter 131 at the aortic arch, the flow of blood pumped from the left atrium is not impeded or interfered with, reducing the occurrence of turbulence and the like.

Example four

Referring to fig. 17 to 19, the present embodiment is different from the second embodiment in the structure of the embolic filter 13. The embolic filter 131 comprises a sheet-like structure made of a shape memory material, and in a natural state, the thickness of the middle portion of the sheet-like structure is greater than the thickness of the two ends, and the middle portion of the sheet-like structure is arched. It can be understood that the middle part of the sheet structure faces the opening of the blood vessel, the middle part is thicker and arched to be attached to the opening and closing of the blood vessel, and the effect of intercepting embolic debris is better.

Specifically, in the present embodiment, the embolic filter 13 is a fusiform sheet structure, and the curvature of the side profile of the embolic filter 13 is adapted to the curvature of the blood vessel of the aortic arch branch section. When released, the embolic filter 13 should conform well to the aortic arch branch vessel and completely cover the three branch vessel openings to prevent embolic debris from entering the interior of the branch vessel.

EXAMPLE five

The present embodiment differs from the first embodiment in that the valve dilation system 10 further comprises at least one pressure sensor, which is provided at the valve dilator 12 and/or the embolic filter 131.

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

For a patient with aortic stenosis, because the valve opening is small, the blood flow of the left ventricular outflow tract is blocked, the blood flow speed is accelerated, and the pressure is increased, so that the pressure difference between the preoperative and the postoperative becomes an effective index for judging the treatment effect in the minimally invasive intervention operation for treating aortic stenosis. In the current technology, the commonly used differential pressure measurement mode is to acquire the corresponding pressure values of the high-speed blood flow spectrum analysis of the left ventricular outflow tract before and after the operation through the Doppler effect of the color Doppler ultrasound, and then compare the changes of the pressure values before and after the operation, thereby judging the effect of the operation. The blood pressure value in the operation can not be displayed in real time by adopting an ultrasonic measurement mode, the blood pressure value at a certain moment can be statically stored only by the judgment of a doctor, and comparison is made.

The mode that pressure sensor measures blood flow pressure is adopted to this embodiment, and external equipment can demonstrate the pressure curve of blood flow in real time, and doctor's accessible this curve judges whether the expansion of valve reaches the state of expectation, and is simpler and result more directly perceived accurate, has reduced the degree of difficulty of doctor's operation, has improved the efficiency of operation.

Claims

1. A multi-stent valve dilator, comprising:

at least one expandable inner stent disposed within said outer stent, said inner stent comprising opposing second proximal and second distal ends and at least one reinforcing arm connected between said second proximal and second distal ends, said reinforcing arm at least partially conforming to and fixedly connecting said expansion arm, said second proximal end fixedly connecting said first proximal end, and said second distal end fixedly connecting said first distal end.

2. The valve dilator of claim 1, wherein said dilating arm comprises a cutting section and two first support sections disposed at opposite ends of said cutting section, wherein the other end of one of said first support sections is connected to said first proximal end, the other end of the other of said first support sections is connected to said first distal end, and said cutting portion is disposed at said cutting section.

3. The valve dilator of claim 2, wherein each said first support section comprises two support rods, one end of each of said two support rods being joined and fixedly connected to one end of said cutting section, the other end of each of said two support rods being joined and fixedly connected to said first proximal end or said first distal end.

4. The valve dilator of claim 2, wherein said cutting segment is substantially parallel to a central axis of said outer stent.

5. The valve dilator of claim 2, wherein the reinforcing arm comprises a reinforcing segment and two second support segments respectively disposed at two ends of the reinforcing segment, wherein the other end of one of the second support segments is connected to the second proximal end, the other end of the other of the second support segments is connected to the second distal end, and the reinforcing segment is fixedly connected to the cutting segment.

6. The valve dilator of claim 5, wherein the length of the reinforcing segment is less than or equal to the length of the cutting segment, the reinforcing segment conforming to and fixedly connecting with at least a portion of the cutting segment.

7. The valve dilator of claim 1, wherein the first distal end and the first proximal end are hollow tubular structures, and hollow grooves are circumferentially arranged on the first distal end and the first proximal end; and/or the presence of a gas in the gas,

the second far end and the second near end are both hollow tubular structures, and hollow grooves are formed in the circumferential directions of the second far end and the second near end.

8. The valve dilator of claim 1, wherein said outer stent and said inner stent are each insulated or covered with an insulating coating, said cutting portion comprising at least one conductive electrode.

9. The valve dilator of claim 1, wherein said inner stent is an insulator or covered with an insulating coating, said outer stent is covered with an insulating coating except for said cut portion, said cut portion being a conductive portion.

10. A valve dilation system comprising a tube assembly and the valve dilator of any one of claims 1 to 9, wherein said first proximal end is fixedly secured to said second proximal end and said first distal end is fixedly secured to said second distal end, said tube assembly comprising a defining head, an inner tube, a first intermediate tube, and an outer tube, said inner tube slidably secured to said first intermediate tube, said first intermediate tube slidably secured to said outer tube, said inner tube passing through said first proximal end, said second distal end in sequence and extending out of said first distal end and said defining head fixedly connected, said first intermediate tube fixedly connected to said first proximal end.

11. The valve expansion system of claim 10, further comprising an embolic protection device comprising an embolic filter and a suction mechanism, the catheter body assembly further comprising a second intermediate tube, the first intermediate tube slidably disposed within the second intermediate tube and the second intermediate tube slidably disposed within the outer tube, the embolic filter secured to a distal end of the second intermediate tube, the suction mechanism secured to a proximal end of the second intermediate tube and in communication with a lumen of the second intermediate tube.

12. The valve dilation system of claim 11 wherein the distal end of the embolic filter is open, the proximal end of the embolic filter is gradually gathered and fixedly attached to the distal end of the second intermediate tube, and the embolic filter is in a diverging expanded state from the proximal end to the distal end when the embolic filter extends from the distal end of the outer tube.

13. The valve dilation system of claim 12 wherein the distal end of the embolic filter is provided with a fixation site for abutment with an inner wall of a blood vessel, the fixation site being recessed radially inward of the valve dilator.

14. The valve dilation system of claim 11 wherein the embolic filter comprises a sheet-like structure made of a shape memory material, the sheet-like structure having a thickness in a middle portion that is greater than a thickness at both ends, and the sheet-like structure having a middle portion that is domed.

15. The valve dilation system of claim 11, further comprising at least one pressure sensor provided to the valve dilator and/or the embolic filter.