Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be understood that the directions or positional relationships indicated by "front", "rear", "upper", "lower", "left", "right", "longitudinal", "transverse", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail", etc. are configured and operated in a specific direction based on the directions or positional relationships of the drawings, are merely for convenience of description of the present invention, and do not indicate that the apparatus or element referred to must have a specific direction, and thus should not be construed as limiting the present invention.
It should also be noted that unless explicitly stated or limited otherwise, terms such as "mounted," "connected," "secured," "disposed," and the like are to be construed broadly, and may be fixedly connected, detachably connected, or integrally formed, directly connected, indirectly connected via an intermediate medium, or in communication between two elements or in an interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, it can be "directly" or "indirectly" on the other element or one or more intervening elements may also be present. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present invention, it should be still noted that, the proximal end refers to the end of the instrument or component that is close to the operator, the distal end refers to the end of the instrument or component that is far away from the operator, the axial direction refers to the direction parallel to the line connecting the distal end and the center of the proximal end 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 around the axial direction.
In order to overcome the defect that an expanding arm is easy to collapse in the cutting process of a valve expander in the prior art, the invention discloses a multi-bracket valve expander and a valve expanding system. The invention is illustrated by way of specific examples in the following description taken in conjunction with the accompanying drawings.
Example 1
Referring to fig. 2-9, the present invention provides a multi-stent valve dilator 12 comprising an expandable outer stent 121 and at least one expandable inner stent 122. The outer stent 121 includes opposed first distal and proximal ends 1212, 1211, and at least two expansion arms 1210 connected between the first distal and proximal ends 1212, 1211. At least one of the expansion arms 1210 is provided with a cutting portion 1215 on the side facing away from the remaining expansion arms 1210. The inner stent 122 is disposed within the outer stent 121, the inner stent 122 including opposed second proximal and distal ends 1221, 1222 and at least one reinforcement arm 1220 connected between the second proximal and distal ends 1221, 1222. The reinforcement arm 1220 at least partially engages and is fixedly coupled to the expansion arm 1210, the second proximal end 1221 is fixedly coupled to the first proximal end 1211, and the second distal end 1222 is fixedly coupled to the first distal end 1212.
According to the technical scheme of the embodiment, the cutting part 1215 of the expansion arm 1210 is utilized to gradually cut and continuously expand the valve adhesion part, the outer support 121 and the inner support 122 jointly provide support for the expansion arm 1210, the reinforcing arm 1220 of the inner support 122 is fixed with the expansion arm 1210, the support force can be increased for the outer support 121 in the process of cutting and expanding the valve, a stress fulcrum can be additionally arranged on the expansion arm 1210 to prop up the expansion arm 1210, the expansion arm 1210 has the support force under the action of the same concentrated load, and deformation is less prone to occur, so that the situation that the expansion arm 1210 collapses due to insufficient valve resistance and self-supporting force of the outer support 121 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 operation is improved.
The valve expander 12 is arranged in a multi-stent structure, and aims to increase the supporting force of the outer stent 121 in the valve expanding process, so that the condition that the outer stent 121 cannot support and continuously expand the valve due to the fact that the supporting force is weak and the external resistance is large in the expanding process is prevented, and the stent collapses is avoided. 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 supporting points at the two ends of the beam are points a and B, and are supported by the supporting forces FA and FB, when the inner bracket 122 is present, i.e., the supporting force FC is increased to the beam at point C, the simple-support beam model is changed into an hyperstatic beam, i.e., additional constraint FC is added, thereby 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 coaxially secured within the outer stent. It is of course conceivable that the present invention is not limited to a double stent configuration, but that a triple stent configuration is equally applicable to the present invention, i.e. the valve dilator 12 comprises 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 more.
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, and the pulmonary valve, considering the anatomical structure of the valve, and at least two expansion arms 1210 considering the inner stent 122 disposed inside the outer stent 121. The expansion arms 1210 can radially expand into the calcified junctions of adjacent leaflets, and the adhesion sites on the adjacent leaflet junctions can be cut, such as by mechanical cutting or ablative cutting, by the cutting portion 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 unevenly circumferentially arranged. The two and three stent arms 1210 can be used in two-leaflet and three-leaflet stenosis, respectively. Because the cutting portions 1215 of the two or three expansion arms 1210 do not form a cylinder shape similar to the middle of the balloon around the circumference, the cutting portions 1215 of the valve expander 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 orifice and alleviating a series of adverse symptoms caused by stenosis. Notably, the number of expansion arms 1210 is not desirably provided in excess, preventing all of the expansion arms 1210 from circumferentially contacting the leaflets like a balloon and not entering the interface gap between adjacent leaflets.
The outer stent 121 should preferably have an outer diameter maximum radial dimension of between 10-25mm in a natural state in consideration of the actual radial dimension of the human orifice. 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 reinforcement arms 1220 of the inner stent 122 may be one, with the reinforcement arms 1220 at least partially conforming to and fixedly attached to one of the expansion arms 1210. Preferably, to ensure the overall stability of the outer stent 121, the number of reinforcing arms 1220 is identical to that of the expansion arms 1210, and the reinforcing arms 1220 are uniformly spaced apart in the circumferential direction as well as the expansion arms 1210 and fixedly connected in one-to-one correspondence.
The maximum radial dimension of the outer diameter of the inner bracket 122 in the natural state should be equal to the maximum radial dimension of the inner diameter of the outer bracket 121 in the natural state, so as to ensure that the outer wall of the reinforcing arm 1220 of the inner bracket 122 can be just attached to the inner wall of the expanding arm 1210 of the outer bracket 121 when the inner bracket 122 is sleeved in the outer bracket 121 in the natural state, so as to better fixedly connect the two brackets together. Referring to fig. 2 and 3, the length of the expansion arm 1210 is slightly greater than the length of the reinforcement arm 1220 to ensure that the joint length of the two is greater and the support capability of the expansion arm 1210 is greater. Referring to fig. 8 and 9, in some embodiments, the bonding length between the reinforcement arm 1220 and the expansion arm 1210 is smaller, and the bonding fixing portion is disposed in the middle of the reinforcement arm 1220 to ensure that the reinforcement arm 1220 supports the expansion arm 1210 uniformly.
Referring to fig. 4 and 5, the expansion arm 1210 includes a cutting section 1214 and two first support sections 1213 disposed at opposite ends of the cutting section 1214. The other end of one of the first support sections 1213 is connected to the first proximal end 1211 and the other end of the other first support section 1213 is connected to the first distal end 1212, with the cutting portion 1215 being provided on the cutting section 1214. It will be appreciated that the first support section 1213, which is adjacent to 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 one side of the first distal end 1212 is connected at one end to the first distal end 1212 and at one end to the cutting section 1214. Thus, the first support section 1213 functions to support both ends of the cutting section 1214. The cutting portion 1215 is provided in the intermediate cutting section 1214, which facilitates cutting of the cutting portion 1215 in alignment with the adhesion site on the adjacent leaflet boundary.
The expansion arms 1210 are arranged in segments, and when the first proximal end 1211 and the first distal end 1212 are moved axially relative to each other, each first support section 1213 connects one end of the corresponding cutting section 1214 to vary the radial distance between the central axis X of the outer stent 121 (coinciding with the central axis Z of the valve expander) to adjust the radial distance between the cutting section 1214 and the central axis X. Specifically, when the first proximal end 1211 axially approaches the first distal end 1212, the axial distance between the first proximal end 1211 and the first distal end 1212 decreases, the radial distance between the 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 progressively cuts the adhesion at different radial positions on the boundary between adjacent leaflets to adapt to the physiological anatomical differences of different individual valves (the progressive cutting firstly maintains a radial distance between the cutting segment 1214 and the central axis X, and after a certain time of cutting, the radial distance between the cutting segment 1214 and the central axis X increases slightly, and the cutting is continuously performed, so as to perform the cycle). As 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 the end of each first support segment 1213 connecting the respective cutting segment 1214 and the central axis X decreases, such that the radial distance between the cutting segment 1214 and the central axis X decreases accordingly, to facilitate receiving 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., any point of the cutting segment 1214 is substantially the same distance from the central axis X, with a deviation of less than 0.5mm. Specifically, when the valve dilator 12 is in its natural state, the first support section 1213 is inclined outwardly relative 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 is radially expanded or contracted, and the cut sections 1214 may remain substantially parallel to the central axis X due to the adjustment of the radial distance of the cut sections 1214 from the central axis X by the radial distance variation of the end of each first support section 1213 connecting the corresponding cut section 1214.
In this embodiment, the cutting section 1214 is substantially straight rod presenting a parallel axial direction. It is of course contemplated that in other embodiments, wavy rods or other forms of rods are possible, with only the cutting segment 1214 meeting the mechanical requirements used herein, ensuring 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, more preferably between 15-25mm in length, considering the height of the leaflet when moving in the body. The width of the cutting section 1214 should preferably be between 0.8-1.5mm and the wall thickness preferably between 0.3-0.5 mm.
Referring to fig. 4 and 5, each first support segment 1213 includes two support rods 12131, one end of each support rod 12131 is joined to and fixedly connected with one end of the cutting segment 1214, and the other end of each support rod 12131 is joined to and fixedly connected with either the first proximal end 1211 or the first distal end 1212. Of course, each first support segment 1213 may be a single support rod.
Specifically, the first support section 1213 may be formed by combining two support rods 12131 that radially extend outward in the axial direction of the outer bracket 121 and that finally meet. One end of the two support rods 12131 forms a first junction 12132 with the cutting section 1214 and the other end forms a second junction 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, two support rods 12131 are similar to diamond shapes, one ends of the two support rods 12131 are gathered at one end of the cutting section 1214 to form a first junction 12132, and the other ends are gathered at the first proximal end 1211 or the first distal end 1212 to form a second junction 12133. The first support segment 1213 is a separate, refocused structure that increases the stability of the valve dilator 12, particularly when the valve dilator 12 is axially contracted, and greatly reduces torsional deformation of the valve dilator 12 that may occur when 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 circumferences of the first distal end 1212 and the first proximal end 1211. Specifically, the 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, preferably the hollow grooves are spiral. The hollowed out grooves may increase the surface roughness of the first proximal end 1211 and the first distal end 1212, ensuring the attachment integrity and material adhesion of the valve dilator 12 when interconnected with the associated structure on the delivery device, to enhance its resistance to pull-out.
Referring to fig. 6 and 7, the inner bracket 122 is similar in structure to the outer bracket 121. The inner support 122 includes a second proximal end 1221, a second distal end 1222, and a reinforcement arm 1220 connected between the second proximal end 1221 and the second distal end 1222.
Specifically, the reinforcing arm 1220 includes a reinforcing section 1223 and two second support sections 1224 provided at both ends of the reinforcing section 1223, respectively. The other end of one of the second support sections 1224 is connected to the second proximal end 1211 and the other end of the other second support section 1224 is connected to the second distal end 1212.
It is to be understood that the second support section 1224 of the inner bracket 122 may be formed by extending and gathering two support rods as the first support section 1213 of the outer bracket 121, and the specific structure thereof is described above, which is not repeated herein. Of course, the second support section 1224 may also be formed from a single support rod, and in particular, a single support rod may be formed from a second proximal end 1221 or a second distal end 1222 that extends radially outwardly in an axial direction and eventually meets both ends of the reinforcement section 1223 of the inner bracket 122. The reinforcing section 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), so that the reinforcing section 1223 is conveniently and fixedly connected with the cutting section 1214. In order to facilitate the connection of the reinforcing section 1223 to the cutting section 1214, the reinforcing section 1223 should have a width that corresponds to the width of the cutting section 1214, the length of the reinforcing section 1223 being less than or equal to the length of the cutting section 1214, and the reinforcing section 1223 being in engagement with and fixedly attached to at least a portion of the cutting section 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, with hollow grooves in the circumferential direction 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 over and secured to the second proximal end 1221 and the first distal end 1212 can be sleeved over and secured to the second distal end 1222. The hollowed out grooves of the second distal end 1222 and the second proximal end 1221 facilitate improved connection stability of the inner bracket 122 and the outer bracket 121.
Referring to fig. 3, 5 and 7, the second proximal end 1221 of the inner housing 122 extends through the lumen of the first proximal end 1211, and the second distal end 1222 extends through the lumen of the first distal end 1212 and is received therein such that the inner housing 122 is disposed within the outer housing 121. At this time, the outer wall of the reinforcing 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 reinforcing section 1223 and the cutting section 1214 may be fixedly connected together by a connecting member.
Specifically, referring to fig. 3 to 7, the outer bracket 121 is provided with connection holes 1216 at both ends of the cut section 1214, two for each end of the connection holes 1216. The reinforcing section 1223 of the inner bracket 122 is provided with the same number of connecting holes 1225 at the corresponding positions. The connecting members such as wires 123 are respectively passed through the connecting holes provided at the same portion of the inner bracket 122 and the outer bracket 121 to the inner wall of the inner bracket 122, at this time, a fixing piece 124 is installed on the inner wall of the reinforcing section 1223 of the inner bracket 122, and the wires 123 are passed through the two holes of the fixing piece 124 and welded to the back surface of the fixing piece 124, thereby firmly fixing the inner bracket 122 and the outer bracket 121 together. Of course, the fixing piece 124 may be omitted, and the reinforcing section 1223 and the cutting section 1214 may be directly and fixedly connected together by a connecting member. The positions and the number of the connecting holes of the inner and outer brackets 121 are not limited to this, and for example, the positions of the connecting holes may be provided in the middle portion between the cut sections 1214 of the outer brackets 121 and the reinforcing sections 1223 of the inner brackets 122.
In other embodiments, the securement of the outer bracket 121 and the reinforcement section 1223 of the inner bracket 122 may be accomplished by one or more rivets passing through the cut section 1214 of the outer bracket, respectively. Of course, the cut sections 1214 and the reinforcement sections 1223 may also be wrapped with a sheet metal piece, and then the inner and outer brackets 122 and 121 may be fixedly connected together by welding the sheet metal pieces.
Referring to fig. 4, the cutting portion 1215 of the outer stent 121 is electrically conductive at least at the surface of the valve tissue contacting surface, 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 portion on the boundary between adjacent valve leaflets. The principle of ablation cutting is that the cutting part 1215 and the 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 rapidly oscillate, cells are cracked and vaporized, and adhesion parts on the junctions of adjacent valve leaflets are disconnected to realize cutting. Ablation cutting has good effect on valve stenosis and can reduce tissue injury and effectively avoid bleeding.
In this embodiment, the outer and inner brackets 121 and 122 are each an insulating member or covered with an insulating coating, and the cut 1215 includes at least one conductive electrode. Specifically, the outer bracket 121 and the inner bracket 122 are integrally insulated, the cut portion 1215 is electrically conductive through at least one exposed conductive electrode independent of the outer bracket 121, and the conductive electrode may be fixedly connected to the middle portion of the cut section 1214 of the outer bracket 121 by bonding, crimping, welding, or the like. The morphology of the conductive electrode includes, but is not limited to, ring, sheet or filament like structures. The cutting portion 1215 may be provided with one or more conductive electrodes at the middle of the cutting section 1214 according to specific performance requirements. It will be appreciated that when a plurality of conductive electrodes are provided on a single cutting segment 1214, the plurality of conductive electrodes are preferably evenly distributed axially across the cutting segment 1214 and are correspondingly distributed about the central axis of the 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 leg 122 is an insulator or covered with an insulating coating, the outer leg 121 is covered with an insulating coating except for the cut portion 1215, and the cut portion 1215 is a conductive portion. Specifically, the inner bracket 122 is integrally insulated, and the cut portion 1215 of the outer bracket 121 is a conductive portion that can be electrically conductive, and other portions are insulated. In this embodiment, the energy generating device 11 may be electrically connected to the first proximal end 1211 by 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 bracket 121 and/or the inner bracket 122 should have high insulating strength, not be easily broken down by voltage, and the insulating coating should have excellent adhesion to the bracket, not be easily detached under 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, a parylene coating, etc., although other coatings having the above properties and suitable therefor may be employed.
The outer bracket 121 and the inner bracket 122 may be cut from metal tubes made of nickel-titanium alloy, copper-nickel alloy, copper-aluminum alloy, copper-zinc alloy, etc. Besides the integral cutting of the pipe, the process can also be realized by separately manufacturing all parts and welding. Because the nitinol tube has good metal memory, excellent strength and rigidity, and excellent elastic properties, in this embodiment, the outer and inner brackets 121 and 122 are preferably formed by cutting and shaping a single nitinol tube. Specifically, the cutting is completed by using a single nickel-titanium tube with a proper length under a laser cutting machine, the cutting is completed, the shaping treatment is performed again, and the cut and shaped inner and outer brackets 121 are integrally in a radial expansion state with a small amplitude in the radial direction in a free state.
Referring to fig. 11-13, a valve dilation system 10 is also disclosed in accordance with a first embodiment of the present invention, comprising 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 disposed on the second proximal end 1221, and the first distal end 1212 is fixedly disposed on the second distal end 1222. The tube body assembly 14 includes a defining 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 intermediate tube 143 and the outer tube 145 of the tube assembly 14 are movably sleeved together in sequence from inside to outside along an axial direction, and a proximal end of the limiting head 141 is fixedly connected with a distal end of the inner tube 142.
Referring to fig. 12, the inner tube 142 sequentially passes through the first proximal end 1211, the second proximal end 1221, the second distal end 1222, and extends beyond the first distal end 1212 to fixedly connect with the defining head 141, and the first intermediate tube 143 is fixedly connected with 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, varies with the sliding of the inner tube 142 and/or the first intermediate tube 143.
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 hollow tubular structures, the second proximal end 1221 of the inner bracket 122 passes through the tube lumen of the first proximal end 1211, the second distal end 1222 passes through the tube lumen of the first distal end 1212 to be sleeved inside thereof, 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 bracket 121 to be fixedly connected with the defining head 141. The fixed connection of the distal end of the inner tube 142 to the defining head 141 and the fixed connection of the distal end of the first intermediate tube 143 to the first proximal end 1211 may be achieved by welding.
The defining head 141 and the first distal end 1212 may be fixedly attached or non-fixedly attached. The fixed connection means that the limiting head 141 and the first distal end 1212 are fixedly connected together in a welded manner, and the first distal end 1212 cannot slide outside the inner tube 142. The 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 slide outside the inner tube 142, out of the defining head 141.
The valve dilation system 10 further comprises a handle 15, the proximal ends of the outer tube 145, the first intermediate tube 143, and the inner tube 142 being connected to a drive mechanism of the handle 15 by which the axial sliding thereof is controlled. For example, the drive mechanism may control the outer tube 145 to slide axially to release or retract the valve dilator 12, and the drive mechanism may control the inner tube 142 to slide axially to effect relative movement with the first intermediate tube 143 to adjust the degree of radial expansion of the valve dilator 12. Specifically, after the outer tube 145 releases the valve dilator 12, the outer tube 145 and the first intermediate tube 143 are kept stationary, and the driving mechanism of the handle 15 controls the inner tube 142 to move proximally, so as to drive the valve dilator 12 to compress axially, and simultaneously gradually expand the expansion arms 1210 along the radial direction, and the cutting portion 1215 gradually ablates and cuts the valve adhesion. Alternatively, the inner tube 142 and the outer tube 145 may be kept stationary, and the driving mechanism of the operating handle 15 may push the first intermediate tube 143 distally, thereby achieving the same effect. 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 dilation system 10 into the human body.
Referring to fig. 11, the valve dilation system 10 further comprises an embolic protection device 13, the embolic protection device 13 comprising an embolic filter 131 and a suction mechanism 132. The tube 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 aspiration mechanism 132 is secured to the proximal end of the second intermediate tube 144 and is in communication with the lumen of the second intermediate tube 144.
It will be appreciated that embolic filter 131 is used by valve dilator 12 to intercept dislodged debris during dilation of a stenosed calcified valve, to prevent it from entering a cerebral vessel through an aortic branch, to cause damage such as stroke, and that aspiration mechanism 132 is used to aspirate embolic debris intercepted by embolic filter 131 out of the body, to further prevent such debris from clogging with blood circulating to other site vessels. The proximal end of the second intermediate tube 144 may be fixedly connected to the drive mechanism of the handle 15, with its axial movement controlled by the drive mechanism, to adjust its position 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 protrudes from the distal end of the outer tube 145, the embolic filter 131 assumes a divergent distended state from the proximal end to the distal end. The distal end of embolic filter 131 is proximal to the surgical site, and debris generated during valve dilation is collected by the open distal end and is then collected proximally and sucked into second intermediate tube 144. Thus, a larger collection volume of the scraps is ensured, and the scraps are matched with the second middle pipe 144, so that the scraps can be directly discharged outside the body through a pipeline intervening in a human body, and the scraps cannot enter or flow through other parts, so that 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 an embolic filter 131 is disposed at the position of the ascending aorta and fully engages the inner wall of the ascending aorta to prevent the detached embolic debris from continuing to flow along with the blood flow to other sites. The outer diameter of the released embolic filter 131 at the maximum outer diameter should be larger than the inner wall diameter of the aortic blood vessel, so that the released embolic filter 131 can be fixed in the inner wall of the blood vessel by being pressed by the inner wall of the blood vessel without being displaced under the impact of blood flow.
The embolic filter 131 may be a filter holder including, but not limited to, a filter membrane attached, a filter mesh attached with a filter membrane, and the like. Specifically, the filter support with the filter membrane attached thereto means that the main body of the embolic filter 131 is formed by cutting or braiding a single tube material by laser, and the filter membrane attached thereto intercepts and filters embolic debris through the filter membrane. The pipe material can be made of superelasticity or shape memory alloy materials such as nickel-titanium alloy, copper-nickel shape memory alloy and the like. The filter pores on the filter membrane are sized to permit passage of blood cells while preventing passage of embolic debris. Preferably, the size of the filter membrane aperture should be greater than 50um, in particular the aperture size may be set according to the size of the actual required intercepted debris.
The filter screen is that the embolic filter 131 is woven from wires of a tube material that are laser cut or cross-laid, preferably woven. For example, a filter mesh woven from nickel-titanium wires or other alloy wires having superelasticity and shape memory may be a filter mesh woven from nylon wires, or a filter mesh woven from a combination of nickel-titanium wires and nylon wires. In consideration of the developing property in the body, a metal material with developing property such as tantalum wire, platinum wire, tungsten wire and the like can be put in at intervals for knitting, so that the developing effect in the body is improved. Preferably, the diameter of the braided filaments is between 0.01 and 0.1mm, more preferably between 0.01 and 0.05mm. 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 50um and 500 um. The woven filter screen attached with the filter membrane is formed by combining the filter membrane and the woven filter screen, and the description is omitted here.
The entire system can effect release and retrieval of the valve dilator 12 and embolic filter 131 by controlling the movement of the outer tube 145 in the axial direction.
The present embodiment illustrates the manner in which the valve dilation system operates using aortic valve dilation as an example, although the valve dilator system 10 and method of operation thereof may be adapted for dilation of other valves, such as mitral valve, tricuspid valve, pulmonary valve, etc.
S1, puncturing the femoral artery by a puncturing device, and after the puncturing is completed, conveying the valve dilator 12 to a position close to the aortic valve by utilizing the cooperation of the guide wire and the inner tube 142.
S2, under the guidance of external medical imaging equipment such as CT, ultrasound and the like, the driving mechanism of the operating handle 15 enables the limiting head 141 to penetrate through the narrow aortic valve, so that the limiting head 141 is positioned on one side of the aortic valve close to the left ventricle.
And S3, the driving mechanism of the operating handle 15 controls the outer tube 145 to slowly move proximally, so that the valve expander 12 gradually exposes out of the outer tube 145, the cutting section 1214 is ensured to be accurately clamped into the junction of the adjacent valve by external medical imaging equipment such as CT, ultrasonic and the like in the releasing process, and calcified adhesion is positioned on the cutting part 1215 of the cutting section 1214. Continued proximal movement of the outer tube 145 then causes the valve dilator 12 to be fully released.
After the valve dilator 12 is completely released, the outer tube 145 is continuously moved proximally to gradually release the embolic filter 131, the embolic filter 131 is abutted against the inner wall of the blood vessel, and the embolic filter 131 is positioned correctly under the guidance of the external medical imaging device. If the release position is less than ideal, the second intermediate tube 144 may be trimmed axially by the drive mechanism of the handle 15 to secure the embolic filter 131 in the correct position in the vessel.
S5, after the valve dilator 12 and the embolic filter 131 are completely released and correctly positioned, the energy generating device 11 is started, and the power is applied to start the ablation cutting of the narrow valve. The suction mechanism 132 should be activated in advance before the power generation device 11 is activated.
And 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 that the valve expander 12 is driven to expand along the radial direction, and the bonded narrow valve is cut through the dual functions of the radio frequency energy of the energy generating device 11 and the mechanical expanding force of the radial expansion of the valve expander 12. While the incision is being dilated, the embolic filter 131 is effective to intercept embolic debris that falls out of the procedure and to aspirate the body through the aspiration mechanism 132.
S7, when the expansion of the aortic valve has reached the desired effect, the energy generating device 11 is turned off, the driving mechanism of the operating handle 15 returns the valve expander 12 to the pre-expansion state, and then the outer tube 145 is moved distally in the axial direction, and the embolic filter 131 and the valve expander 12 are sequentially recovered into the outer tube 145. The system is then evacuated from the body.
Example two
Referring to fig. 15, the difference between the present embodiment and the first embodiment is the structure of the embolic filter 13. In this embodiment, a fixing site 1311 for abutting against the inner wall of the blood vessel is provided at the distal end of the embolic filter 131 according to the anatomical structure of the ascending aorta, specifically, the geometry of the blood vessel, the curvature of the blood vessel, etc., and the fixing site 1311 is recessed inward in the radial direction of the valve dilator 12. The positioning 1311 allows the embolic filter 131 to be better structurally adapted to the anatomy of the aortic vessel, by which the embolic filter 131 is fixed in position in the ascending aorta with good structural fit, thus maintaining position stability under the impact of blood flow.
Example III
Referring to fig. 16, the present embodiment differs from the first embodiment in that the placement site of the embolic filter 131 in the body is changed from the position of the ascending aorta to the site of aortic branching.
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 here. In this embodiment, the embolic filter 131 is positioned in the aortic arch with an outer diameter slightly larger than the diameter of the inner wall of the aortic arch vessel so that the embolic filter 131 can effectively conform to the inner wall of the aortic arch vessel. The axial length of embolic filter 131 should be greater than the furthest distance of the left subclavian artery and brachiocephalic vessel openings to protect embolic debris from entering the aortic arch branch vessels, and particularly into the common carotid artery branch.
The embolic filter 131 is placed in the aortic arch without interfering with or interfering with the flow of blood pumped out of the left atrium, reducing the occurrence of eddies, etc.
Example IV
Referring to fig. 17-19, this embodiment differs from the second embodiment in the construction of the embolic filter 13. The embolic filter 131 includes a sheet-like structure made of a shape memory material, the thickness of the middle of the sheet-like structure being greater than the thickness of both ends in a natural state, and the middle of the sheet-like structure arching. It can be appreciated that the middle part of the sheet structure faces the opening of the blood vessel, and the middle part is thicker and arches to be attached to the opening and closing of the blood vessel, so that the effect of intercepting embolic debris is better.
Specifically, the embolic filter 13 in this embodiment is a fusiform sheet-like structure, and the lateral profile curvature of the embolic filter 13 is adapted to the vessel curvature of the aortic arch vessel branch segment. When released, the embolic filter 13 should conform well to the aortic arch branch segment 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 provided in 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 functions of measuring blood flow pressure are integrated on the energy generating device 11, so that real-time blood flow pressure values are dynamically and continuously displayed on the energy generating device 11 in a curve auxiliary numerical mode, and a doctor can judge the blood flow real-time pressure in the operation process.
For patients with aortic valve stenosis, the left ventricular outflow tract blood flow is blocked, the blood flow speed is increased and the pressure is increased due to the smaller valve opening, so that the pressure difference between the preoperative pressure and the postoperative pressure is an effective index for judging the treatment effect in the operation of minimally invasive interventional treatment of aortic valve stenosis. In the prior art, a commonly used differential pressure measurement mode is to collect the high-speed blood flow spectrum of a left-hand outflow channel before and after an operation to analyze the corresponding pressure value through the Doppler effect of color Doppler ultrasound, and then compare the change of the pressure value before and after the operation so as to judge the operation effect. By adopting an ultrasonic measurement mode, the blood pressure value in the operation cannot be displayed in real time, the blood pressure value at a certain moment can be statically stored only by virtue of the judgment of a doctor, and compared, and the examination method has a great relationship with the subjective judgment and the operation level of the doctor in the operation.
In the embodiment, the pressure sensor is adopted to measure the blood pressure, the external equipment can display the blood pressure curve in real time, and a doctor can judge whether the expansion of the valve reaches the expected state or not through the curve, so that the method is simpler, the result is more visual and accurate, the operation difficulty of the doctor is reduced, and the operation efficiency is improved.