Expansion method and expansion device for an expandable implant device, transcatheter implant device system

Abstract

This application belongs to the field of medical device technology, specifically relating to an expansion method and device for an expandable implantable device, and a transcatheter implantation device system. The expansion method of this application includes: delivering the expandable implantable device to the implantation site in a radially compressed state; applying a first radial expansion force to the expandable implantable device, causing the expandable implantable device to present a first expanded state, in which the diameter of the first end and the second end increases by 50% to 400% compared to the radially compressed state; and applying a second radial expansion force to the expandable implantable device, causing the expandable implantable device as a whole to expand from the first expanded state to a final state with a larger diameter. The expansion method of this application enables the expandable implantable device to expand into a uniform and smooth shape.

Description

Expanding methods and devices for expandable implantable devices, and transcatheter implantable device systems. Technical Field

[0001] This application belongs to the field of medical device technology, specifically relating to an expansion method and expansion device for an expandable implantable device, and a transcatheter implantable device system. Background Technology

[0002] The human body has many lumens, such as blood vessels and the prostate. The size and shape of these lumens vary depending on their location. The most common treatment for lumens stenosis is to implant a stent at the lesion site. The success rate of this treatment is closely related to the compatibility between the stent and the lesion site. Therefore, when designing a stent, the shape and size of the lesion site must be fully considered. When the lesion site is cylindrical, the stent should be designed as a cylindrical stent of the corresponding size. When the lesion site is irregularly shaped, the stent should be designed as an irregularly shaped stent.

[0003] Currently, stents are divided into balloon-expandable stents and self-expanding stents. Each of these two types of stents has its advantages. However, during implantation and release, self-expanding stents can be directly released into the corresponding shape according to the shape of the lesion site, while balloon-expandable stents need to be expanded into the corresponding shape with the help of an expansion device. Therefore, for balloon-expandable stents, especially when applied to irregular lesion lumens, whether the stent can be well fixed at the lesion site is also closely related to the design of the expansion device.

[0004] Taking the pulmonary artery valve as an example, due to the unique structure of the pulmonary valve, most valve frames are currently designed with openings at both ends to facilitate valve positioning. Self-expanding valve frames, such as the Venus-P valve from Hangzhou Qiming, can position a valve with openings at both ends directly to the target location through their own structural design. However, currently available bulbar valves, such as Edwards's, use a combination of a dumbbell-shaped pre-dilatation valve frame and a straight bulbar valve frame for implantation at the target location. This requires implanting both a valve frame and a valve simultaneously, with the valve frame primarily serving a positioning function. This not only complicates the procedure but also places a greater burden on the patient due to the excessive number of implants at the lesion site. The more foreign objects implanted, the worse it is for the body. Furthermore, after the valve and pre-dilatation valve are implanted, as they become endometrialized within the body, they occupy a large volume of the lumen, leading to a reduction in lumen size and problems such as insufficient blood supply. Therefore, this invention provides a device suitable for large and / or irregularly shaped lumens that achieves the same effect as Edwards's bulbar valve with only one valve. The present invention also provides a valve frame system, which, when combined with an expansion device, enables the implantation of a single valve into the target lesion site and achieves the corresponding effect.

[0005] Heart valves are one-way valves between the atria and ventricles or between the ventricles and arteries. Heart valve disease is one of the most common cardiovascular diseases. Clinically, single or multiple valve structural or functional abnormalities caused by rheumatic inflammation, degenerative changes, congenital malformations, ischemic necrosis, trauma, etc., can lead to valvular stenosis or insufficiency. Mild cases of heart valve disease can be treated with medication to relieve symptoms, while severe cases may require valve repair. Patients who are not suitable for repair require artificial heart valve replacement.

[0006] Heart valve replacement refers to the replacement of a heart valve with an artificial mechanical valve made of synthetic materials or an artificial biological valve made of biological tissue. Transcatheter heart valve replacement (TCVHR) is a commonly used procedure. An interventional catheter is inserted through the femoral vein, radial artery, or apex of the heart to deliver a compressed artificial heart valve to the original valve location and unfold it, ensuring stable placement of the artificial valve at the target implantation site. An artificial heart valve typically consists of a valve frame and biomaterial leaflets sutured to the inside of the frame. Based on the unfolding method, artificial heart valves can be divided into self-expanding valves and balloon-expandable valves. Patent document US20210346158A1 discloses a self-expanding artificial pulmonary artery valve, while patent document US20240024101A1 discloses a balloon-expandable artificial pulmonary artery valve. Both types have their advantages and are suitable for different situations. Generally speaking, current balloon-expandable valves typically have short valve frames, while self-expanding valves typically have long valve frames. In addition, similar situations exist with vascular stents. For example, peripheral vascular stents are generally longer than coronary stents. Currently, self-expanding stents occupy a larger share of the peripheral vascular stent market, while coronary stents are mostly balloon-expandable.

[0007] When balloon dilation is used to expand various stents (including valve stents), especially large-diameter and long stents, the large stent diameter, combined with the expansion of the conical portions at both ends of the balloon after filling with fluid, can cause the stent to expand outwards beyond its expected angle. This can lead to individual stent struts detaching from the overall outline and forming barbs. It can also cause some stent patterns to be squeezed inwards, resulting in insufficient expansion of some patterns and overstretching of others, potentially even causing some stent struts to break. These phenomena result in poor uniformity and smoothness of the deployment morphology of luminal stents, heart valves, and other implantable devices at the target location, leading to insufficient support at the implantation site. In severe cases, this can cause implantation failure, or even if implantation is successful, it can easily lead to restenosis, valvular insufficiency, regurgitation, and other subsequent problems, seriously endangering the patient's health.

[0008] Therefore, there is an urgent need to develop an expansion device and expansion method that can make the expansion shape of the expandable implantable device uniform and smooth, thereby improving the overall safety of the device. Summary of the Invention

[0009] To address the aforementioned technical problems, the present application provides an expansion method for an expandable implantable device, an expansion device for an expandable implantable device, and a transcatheter implantation device system, which can improve the uniformity, smoothness, and fullness of the final expansion shape of the expandable implantable device, thereby enhancing the overall safety of the device.

[0010] The first aspect of this application provides a method for expanding an expandable implantable device, the method comprising:

[0011] The expandable implantable device is delivered to the implantation site in a radially compressed state;

[0012] A first radial expansion force is applied to the expandable implantable device, causing the expandable implantable device to present a first expanded state, wherein the diameter of the axially opposite first end and second end of the expandable implantable device in the first expanded state is increased by 50% to 400% relative to the diameter of the expandable implantable device in the radially compressed state.

[0013] A second radial expansion force is applied to the expandable implantable device, causing the expandable implantable device to expand from the first expansion state to a final state, wherein the diameter of the first end and / or the second end in the final expansion state is greater than the diameter in the first expansion state.

[0014] Another aspect of this application provides an expansion device for an expandable implantable device, the expansion device comprising a catheter assembly and a balloon portion, wherein the catheter assembly includes at least one catheter; the balloon portion is connected to and fixed to the distal end of the catheter assembly and is capable of loading the radially compressed expandable implantable device, the balloon portion including a first inner balloon, a second inner balloon, and an outer balloon; the first inner balloon and the second inner balloon are fitted inside the outer balloon, the first inner balloon and the second inner balloon being used to provide a first radial expansion force to the axially opposite first and second ends of the expandable implantable device when inflated, such that the diameter of the first end and the second end is increased by 50% to 400% relative to the diameter of the radially compressed expandable implantable device; the outer balloon is used to provide a second radial expansion force to the expandable implantable device when inflated to expand the expandable implantable device to its final state.

[0015] Another aspect of this application provides a transcatheter implantation device system, which includes the aforementioned expansion device and expandable implantable device. The expandable implantable device mounted thereon can be expanded according to the aforementioned expansion method using the expansion device.

[0016] The expansion method and apparatus for the expandable implantable device proposed in this application expands the two ends of the radially compressed expandable implantable device to a first expansion state that is not fully expanded, and then further expands the expandable implantable device from the first expansion state to the final state. This provides a buffer process for the expansion of the expandable implantable device. Since the first radial expansion ratio is between 50% and 400%, the degree and range of expansion in the two stages are fully balanced. This prevents excessive local concentration of expansion force in each expansion stage, which could cause uneven stress on the support rod of the expandable implantable device. This avoids outward barbs protruding beyond the overall outline of the support rod, or poor unfolding shape caused by inward extrusion of the pattern. As a result, the unfolding shape of the expandable implantable device is more uniform, the outline is smooth and barb-free, and the positioning accuracy is more ideal, thereby improving the safety of the device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 is a flowchart illustrating the expansion method of an expandable implantable device according to one embodiment of this application;

[0019] Figure 2 is a schematic diagram of an expandable implantable device in a radially compressed state, using an example of the expansion method provided in this application;

[0020] Figure 3 is a schematic diagram of an expandable implantable device in a first expanded state, using an example of the expansion method provided by the embodiments of this application.

[0021] Figure 4 is a schematic diagram of an expandable implantable device in a first expanded state, using another example of the expansion method provided by the embodiments of this application.

[0022] Figures 5 and 6 are schematic diagrams of an expandable implantable device in a first expanded state, representing another example of the expansion method provided by the embodiments of this application.

[0023] Figure 7 is a schematic diagram of the expandable implantable device in its final state using the expansion method provided in the embodiments of this application;

[0024] Figure 8 is a structural schematic diagram of an expansion device for an expandable implantable device provided in one embodiment of this application in one state;

[0025] Figure 9 is a schematic diagram of the expansion device shown in Figure 8 in another state;

[0026] Figure 10 is an enlarged cross-sectional structural diagram of the balloon section of the expansion device shown in Figure 8;

[0027] Figure 11 is a schematic diagram of the combined structure of the expandable implantable device and the balloon in a radially compressed state according to an embodiment of this application.

[0028] Figure 12 is a schematic cross-sectional view of the balloon section shown in Figure 8 in the first inflated state.

[0029] Figure 13 is a schematic diagram of the combined structure of the expandable implantable device and the balloon in the first expanded state according to an embodiment of this application.

[0030] Figure 14 is a schematic cross-sectional view of the balloon section shown in Figure 8 in the second inflated state.

[0031] Figure 15 is a schematic diagram of the combined structure of the expandable implantable device and the balloon in the second expanded state according to one embodiment of this application.

[0032] Figure 16 is a structural schematic diagram of an expandable implantable device and expansion apparatus according to another embodiment of this application;

[0033] Figure 17 is a schematic diagram of the overall structure of the expansion device shown in Figure 8 when the balloon is in the second inflated state.

[0034] Figure 18 is a cross-sectional view of the expansion device shown in Figure 17 along line AA;

[0035] Figure 19 is a cross-sectional schematic diagram of the conduit assembly according to two different embodiments of this application;

[0036] Figure 20 is a partial cross-sectional structural schematic diagram of the expansion device according to another embodiment of this application;

[0037] Figure 21 is a schematic diagram of a comparative balloon structure of this application. Detailed Implementation

[0038] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0039] It should be noted that if the symbol “ / ” is used in this application, it means “or”, such as “required / applicable in vivo”, which means required or applicable in vivo.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of conflict, this document, including the definitions, shall prevail. Preferred methods and materials are described below, although similar or equivalent methods and materials described herein may be used to practice or test the invention. The materials, methods, and embodiments disclosed herein are illustrative only and not restrictive.

[0041] The term “approximately” or “substantially” used with respect to a quantity includes variations of the listed quantity that are equivalent to the listed quantity, such as quantities that are not significantly different from the listed quantity used for the intended purpose or function.

[0042] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0043] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0044] It should be understood that, for ease of description, the terms “proximal end” and “distal end” are used in this application, where “proximal end” refers to the end closer to the operator and “distal end” refers to the end farther from the operator.

[0045] This application discloses an expansion method and device for expandable implantable devices. The expandable implantable devices include implants such as artificial heart valves, vascular stents, urinary stents, and biliary stents. Specifically, the expandable implantable device 1 can be various implantable devices with radial compression and expansion states, such as artificial pulmonary valves, artificial aortic valves, artificial mitral valves, artificial tricuspid valves, thoracic / abdominal aortic stents, pulmonary stents, coronary stents, peripheral vascular stents, vena cava stents, and biliary stents, and can be implanted into the human body via catheterization. The substrate of the expandable implantable device can be a metallic material or a polymer. Further, the substrate can be made of ferroalloys, pure iron, magnesium alloys, pure magnesium, zinc alloys, pure zinc, cobalt-chromium alloys, stainless steel, nickel-titanium alloys, polymers, etc., and may or may not have a drug-eluting coating.

[0046] Please refer to Figure 1, which illustrates an expansion method for an expandable implantable device according to one embodiment of this application. The expansion method includes the following steps:

[0047] S01: Deliver the expandable implantable device to the implantation site in a radially compressed state;

[0048] S02: Apply a first radial expansion force to the expandable implantable device, causing the expandable implantable device to present a first expansion state, wherein the diameter of the axially opposite first end and second end of the expandable implantable device in the first expansion state is increased by 50% to 400% relative to the diameter of the expandable implantable device in the radial compression state.

[0049] S03: Apply a second radial expansion force to the expandable implantable device, such that the expandable implantable device expands from the first expansion state to the final state, wherein the diameter of the first end and / or the second end in the final expansion state is greater than the diameter in the first expansion state.

[0050] To facilitate the explanation of the expansion method of the embodiments of this application, the following detailed description is mainly based on the expandable implantable device 1 in Figures 2-7 and the expansion device 2 in Figures 8-19. As an example, the expandable implantable device 1 is an artificial pulmonary valve, which includes a valve frame 10 and valve leaflets 15 connected within the valve frame. The valve frame 10 includes support rods 100 and hollow portions 102, with the support rods 100 interlocking to form multiple hollow portions 102. The material of the valve frame 10 can be absorbable or non-absorbable, such as absorbable materials like iron, magnesium, zinc, and polylactic acid, or non-absorbable materials like nickel-titanium alloy, stainless steel, and chromium-cobalt alloy. This application does not impose any limitations on this.

[0051] In some embodiments, the expansion method of this application delivers the expandable implantable device 1 to the implantation site in a radially compressed state. Referring to Figure 2, the expandable implantable device 1 is loaded in a radially compressed state onto an expansion device 2. The expansion device 2, which carries the expandable implantable device 1, can be inserted into the right ventricular outflow tract via femoral vein puncture, and the expandable implantable device 1 is expanded in the right ventricular outflow tract, thereby fixing the expandable implantable device 1 to the pulmonary valve position to replace the original pulmonary valve.

[0052] When the expandable implantable device 1 is in a radially compressed state, the expansion device 2 passes axially through the expandable implantable device 1. The expandable implantable device 1 is generally a cylindrical structure, in which the support rod 100 of the valve frame 10 is in a contracted state, and the hollow portion 102 takes on a relatively long or narrow shape as the support rod 100 contracts. In the radially compressed state, the axial length of the valve frame 10 of the expandable implantable device 1 is Ls1, the radial width or diameter is Dcr, the distances from the edge of the leaflet 15 to the two ends of the valve frame 10 in the axial direction are Li and Lo, respectively, Li and Lo may be equal or unequal, and the axial length of the leaflet 15 is Lv. As an example, the axial length Lv of the leaflet 15 can be 5 to 30 mm, preferably 9 to 24 mm, specifically 9 mm, 10 mm, 11.5 mm, 12 mm, 13.5 mm, 14.5 mm, 15 to 17 mm, 16.5 to 20 mm, 18 to 22 mm, 21 mm, 23 mm, etc.

[0053] In some feasible implementations, the axial length Ls1 can range from 8 to 150 mm; in some feasible implementations, the axial length Ls1 can range from 20 to 150 mm, and specifically it can be 20 to 30 mm, 20 to 80 mm, 20 to 60 mm, 20 to 50 mm, 40 to 60 mm, 45 to 58 mm, 60 to 78 mm, 85 to 128 mm, 100 to 150 mm, etc. The range of Li or Lo can be 9 to 20 mm, and in some specific examples it can be 9 to 12 mm, 10 to 15 mm, 12 to 18 mm, 16 to 20 mm, etc.

[0054] Referring to Figure 3, in this embodiment, when the expandable implantable device 1 is delivered to the implantation site, an external force is applied to it to change it from a radially compressed state to an expanded state, thereby allowing it to conform to and be fixed with the human body's luminal tissue. In this embodiment, the expansion of the expandable implantable device 1 is performed in stages. First, an external force is applied to the expandable implantable device 1 to bring it to a first expanded state. This first expanded state is not the final expanded state of the expandable implantable device 1, but rather a state between the radially compressed state and the final expanded state. The expansion method of this application achieves staged expansion by applying different radial expansion forces to the expandable implantable device in stages, thereby buffering the uneven expansion caused by the expansion force on the overall expansion of the expandable implantable device 1, resulting in a more uniform and expected unfolded shape. Specifically, in step S02, the diameters of the axially opposite first end 110 and second end 112 of the expandable implantable device 1 in the first expanded state are increased by 50% to 400% compared to the diameter in the radially compressed state. Taking the artificial pulmonary valve as an example, the expandable implantable device 1 is divided into two axial ends, defined as the first end 110 and the second end 112, according to their relative positions with the blood flow after implantation. For example, the first end 110 corresponds to the inflow end, and the second end 112 corresponds to the outflow end, and vice versa. In step S02, the diameter DL of the first end 110 of the partially expanded expandable implantable device 1 increases by 50% to 400% relative to the diameter Dcr of the radially compressed state, and the diameter DR of the second end 112 of the expandable implantable device 1 increases by 50% to 400% relative to the diameter Dcr of the radially compressed state. For ease of description, the diameter increase rate of the first expanded state relative to the radially compressed state is defined as the first radial expansion ratio of the expandable implantable device 1, i.e., (DL-Dcr) / Dcr*100%.

[0055] In some feasible embodiments, the first radial expansion ratio can be 50%–80%, 50%–100%, 50%–200%, 50%–250%, 50%–220%, 50%–300%, 50%–330%, 50%–350%, 70%–100%, 90%–200%, 130%–250%, 180%–220%, 200%–300%, 240%–330%, 100%–350%, 150%–400%, etc. Furthermore, the diameter Dcr of the expandable implantable device 1 in the radial compression state can range from 3 to 8 mm. In some specific examples, the diameter Dcr can be 3–8 mm, 3–5 mm, 4–7 mm, 4–5.6 mm, 4.5–6 mm, etc. In the first expansion state, the diameter DL of the first end 110 can be 4.5–24 mm, and the diameter DR of the second end 112 can be 4.5–24 mm. Further, DL and DR can be 4.5–5.5 mm, 4.5–7.8 mm, 4.7–10 mm, 6.5–12 mm, 9–14 mm, 10.3–15 mm, 12–17 mm, 13–22.5 mm, etc. When the first radial expansion ratio is less than 50%, it is equivalent to the expansion amplitude in the first stage being too small. This may cause excessive diameter change of the expandable implantable device 1 during subsequent expansion to the final state, resulting in inward extrusion of the stent pattern, outward folding of the stent rod near the end, etc., ultimately leading to poor stent deployment morphology. Consequently, the stent's support and fit to human tissue do not meet expectations, failing to achieve the desired clinical effect. When the first radial expansion ratio exceeds 400%, the expandable implantable device 1 in the first expansion state is prone to inward extrusion of the stent pattern and outward folding of the stent rod near the end. When the next expansion is carried out based on this poor intermediate expansion shape and the final state is reached, it is easy for the inwardly extruded and outwardly folded stent rod to be difficult to adjust to the expected compliant shape, which will also lead to poor stent deployment shape in the final expansion state. When the first radial expansion ratio is 180% to 220%, it is particularly suitable for expandable implantable devices 1 with a final expansion diameter of 20 mm or more.

[0056] In some feasible implementations, in the first expansion state, the diameter difference between the first end 110 and the second end 112 is less than 50%, that is, the ratio of the difference between the diameter DL of the first end 110 and the diameter DR of the second end 112 to DL or DR is less than 50%. For example, the difference can be 0 (i.e., DL = DR), or it can be 0% to 5%, 3% to 10%, 8% to 20%, 15% to 30%, 20% to 45%, etc. The smaller the difference, the better the symmetry at both ends under the action of the first radial expansion force, avoiding axial displacement caused by excessive force difference at both ends. This ensures that the expandable implantable device 1 completes expansion at the target position without axial displacement. At the same time, it also avoids the need to add an axial position fine-tuning structure to the delivery system, simplifying the system structure and operation, ensuring the accuracy of the implantation position and reducing the complexity of operation, thereby improving the safety and effectiveness of the surgical procedure.

[0057] In some feasible implementations, the expandable implantable device 1 in the first expansion state can be axially expanded as a whole; in other feasible implementations, the expandable implantable device 1 in the first expansion state can also be axially partially expanded. Referring again to Figure 3, as an example, in step S02, a portion of the axial central region of the partially expanded expandable implantable device 1 can remain in a radially compressed state, i.e., the expansion ratio of this portion is 0. During the transition from the radially compressed state to the first expansion state, the expandable implantable device 1 maintains its axial central portion in a radially compressed state. This radially compressed portion provides axial anchoring force for the device's expansion process. Because the radially compressed portion does not expand, its pattern shape remains unchanged, and the relative positional relationship of the support rods is stable. Using this as a reference, the expanded support rods connected to it are pulled, avoiding uneven force due to local differences in contact with the expansion device caused by the relative displacement of the support rods between the ends and the connecting ends due to radial expansion, thus preventing oblique piercing, twisting, etc. This ensures the flexibility of its unfolded shape and provides a good transitional shape basis for the final expansion state, thereby making the final expansion state meet the implantation requirements.

[0058] In some feasible embodiments, the application range of the first radial expansion force can be from the first end 110 to the first connecting end 114, and from the second end 112 to the second connecting end 116. Correspondingly, the portion of the expandable implantable device 1 whose diameter changes relative to the radial compression state in the first expansion state includes: the portion from the first end 110 to the first connecting end 114; and the portion from the second end 112 to the second connecting end 116. The first connecting end 114 and the second connecting end 116 are located between the first end 110 and the second end 112. The first connecting end 114 is located between the axial center of the expandable implantable device 1 and the first end 110, and the second connecting end 116 is located between the axial center of the expandable implantable device 1 and the second end 112. The diameter of the expandable implantable device 1 located between the first connecting end 114 and the second connecting end 116 remains unchanged in the first expansion state relative to the radial compression state. The first connecting end 114 and the second connecting end 116 serve as the boundary between the radial compression portion and the expansion portion of the expandable implantable device 1 in the first expansion state. The diameter of the expandable implantable device 1 gradually decreases from the first end 110 to the first connecting end 114, i.e., from DL to Dcr. Similarly, the diameter between the second end 112 and the first connecting end 116 gradually decreases from DR to Dcr. In some feasible embodiments, the axial distance Lcr between the first connecting end 114 and the second connecting end 116 is 7.5% to 80% of the axial length Ls1 of the expandable implantable device 1 in the radially compressed state. In some feasible embodiments, the axial distance Lcr between the first connecting end 114 and the second connecting end 116 is 10% to 80% of the axial length Ls1 of the expandable implantable device 1 in the radially compressed state. Specifically, the ratio of the axial distance Lcr between the first connecting end 114 and the second connecting end 116 to the axial length Ls1 of the expandable implantable device 1 in the radially compressed state can be 10%–30%, 15%–40%, 20%–60%, 25%–50%, 30%–65%, 40%–70%, 45%–80%, etc. On the other hand, the axial distance Lcr between the first connecting end 114 and the second connecting end 116 can be 3mm–60mm, and more specifically, it can be 5–20mm, 5–30mm, 8–30mm, 10mm–45mm, 15–50mm, 20–60mm, 25–55mm, etc.As mentioned above, in some feasible embodiments, the axial length Ls1 of the expandable implantable device 1 under radial compression can range from 8 to 150 mm; the axial length Ls1 of the expandable implantable device 1 under radial compression can range from 20 mm to 150 mm; further, the axial length Ls1 of the expandable implantable device 1 under radial compression can range from 20 mm to 80 mm; and even further, the axial length Ls1 of the expandable implantable device 1 under radial compression can range from 20 mm to 60 mm. In some embodiments, the axial length Lv of the leaflet 15 is less than Lcr, and the leaflet 15 is located in the region between the first connecting end 114 and the second connecting end 116. For the expandable implantable device 1 with leaflets 15, since leaflets 15 usually include 2 to 3 leaflets, they are gathered in a certain folded state within the valve frame 10 under radial compression. By expanding both ends of the valve frame 10 in the first expansion state, the leaflets 15 can expand from both ends along with the valve frame 10 in the next overall expansion process, so that the leaflets can be fully unfolded. The adjacent leaflets that make up the leaflets 15 can open smoothly under the action of blood flow, ensuring the smooth flow of blood.

[0059] Furthermore, in some feasible embodiments, the axial length of each end of the expandable implantable device 1 in the first expanded state is 2 to 50 mm, that is, the axial length L from the first end 110 to the first connecting end 114. L The axial length L from the second end 112 to the first connecting end 116 R The values ​​are in the range of 2 to 50 mm, L L With L R They can be equal, or they can have some differences. Specifically, L L or L R It can be 3-10mm, 5-15mm, 8-18mm, 11-22mm, 13-25mm, 16-30mm, 19-34mm, 26-45mm, 31-50mm, etc. Furthermore, L... L L R DL, DR, and Lcr can satisfy equations (1) and (2) based on the aforementioned numerical range: 0° <Arctan((DL-Dcr) / 2L L )≤60°......(1); 0° <Arctan((DR-Dcr) / 2L R )≤60°......(2).

[0060] The parameters L that satisfy the above formula L L RDL, DR, and Lcr enable the expandable implantable device 1 to form a slope at its end during the expansion step in the first stage. That is, a first slope 400, such as a cone or arc, with a diameter decreasing from large, is formed between the first end 110 and the first connecting end 114 of the expandable implantable device 1, and between the second end 112 and the second connecting end 116. Since the first end 110 and the second end 112 of the expandable implantable device 1 are only constrained by the adjacent structure on one side, the first end 110 and the second end 112 are more easily expanded than the middle part during the expansion process. By forming a slope structure towards the center at the two ends of the expandable implantable device 1 in the first expansion state, the expansion between the end and the connecting end is completed in a relatively small range (relative to the change in diameter from radial compression to the final state) in accordance with the above-mentioned expansion characteristics of the expandable implantable device 1 under the action of the first radial expansion force, thus obtaining a better expansion shape and avoiding excessive compression of the support rod near the connecting end. Furthermore, because the slope formed at both ends can play an axial positioning role for the two ends of the expandable implantable device 1, it can avoid axial displacement caused by the unavoidable axial force during the expansion process and ensure that the expandable implantable device 1 unfolds at the precise target position.

[0061] Furthermore, in the first expanded state, the first slope 400 has an angle α. The angle α of the first slope can be defined as the angle formed by the first slope 400 and the central axis O of the expandable implantable device 1, which can also be equivalent to the angle α between the first slope 400 and the extension line of the adjacent straight segment 401 (the straight cylindrical portion that remains compressed between the first connecting end 114 and the second connecting end 116). In the example shown in Figure 3, the first slope 400 is a conical structure, which forms a corresponding oblique line segment on the axial plane from the first end 110 to the first connecting end 114. Therefore, the angle α of the first slope 400 can be directly defined as the angle between the first slope and the extension line of the adjacent straight segment 401 or the central axis O. In other examples, as shown in Figures 4 and 5, the first slope 400 forms an arc segment on the axial plane, where Figure 4 shows a concave surface that is concave inward in the axial direction, and Figure 5 shows a relatively convex surface. At this point, the inclination angle α of the first slope 400 can be defined as the line connecting the first end 110 and the first connecting end 114 on the axial plane. The angle α formed by the extension of the adjacent straight segment 401 is also equivalent to the line connecting the two sides. The angle formed with the central axis O is also defined in this way, and this definition also applies to the conical first slope 400 shown in Figure 3. In some other embodiments, as shown in Figure 6, the angle of the first slope 400 can also be defined as the tangent line passing through the first connecting end 114 and tangent to the first slope 400. The angle α' formed by the extension of the adjacent straight segment 401 is also equivalent to a tangent. The angle formed with the central axis O.

[0062] In some feasible implementations, the oblique angle α is 0° < α ≤ 60°. Further, the oblique angle α can be within the range of examples such as 1°–10°, 5°–25°, 8°–30°, 15°–40°, 20°–50°, and 25°–58°, or example values ​​such as 12°, 18°, 22°, 28°, 32°, 36°, and 42°. If the oblique angle α of the first slope 400 is greater than 0°, it indicates that the end of the expandable implantable device 1 in the first expansion state bulges and expands outward from the connecting end, which has the aforementioned advantages of good expansion shape and avoidance of axial displacement. Meanwhile, if the oblique angle α is within 60°, it can simultaneously prevent the support rod near the connecting end from forming excessively large-angle deformation, thus preventing it from smoothly completing the final expansion shape during subsequent expansion processes.

[0063] It should be understood that the expandable implantable device 1 typically has an axisymmetric structure, and the first slope 400 can be viewed in three-dimensional structure as a surrounding structure symmetrical about the central axis O. Furthermore, although the figure illustrates the specific setting and effect of the angle α using the first slope 400 between the first end 110 and the first connecting end 114 as an example, the first slope 400' formed between the second end 112 and the second connecting end 116 also has a similar angle and a similar effect. It can have the same range or the same value as the aforementioned angle, or it can have the same range but different values; this will not be described in detail here.

[0064] In other embodiments, the expandable implantable device 1 in the first expanded state may be at the critical point between elastic deformation and plastic deformation. On the other hand, in the first expanded state, the expandable implantable device 1 may not be in contact with the tissue structure at the target location, or may be in contact but not exert an expansion force on it. The specific details vary depending on the application scenario and requirements of the expandable implantable device, and will not be described in detail here.

[0065] Referring to Figure 7, in step S03, a second radial expansion force is applied to the expandable implantable device 1, causing it to expand from the first expansion state to the final state. It should be understood that the final state refers to the state where, according to the device's design specifications, the expandable implantable device 1 is fully expanded to meet the expected shape and structure at the target location. Compared to the fully expanded expandable implantable device 1 in the final state, the expandable implantable device 1 in the first expansion state in step S02 is in a partially expanded state, representing an intermediate transitional state between radial compression and full expansion. In the final state, the expandable implantable device 1 as a whole further expands radially relative to the first expansion state.

[0066] In some feasible implementations, the diameter Din of the first end 110 in the final state is 1.5 to 4.5 times the diameter DL of the first end 110 in the first expanded state, and the diameter Dout of the second end 112 in the final state is 1.5 to 4.5 times the diameter DR of the second end 112 in the first expanded state. Further, as mentioned above, DL and DR are 4.5 to 24 mm; Din and Dout are 10 to 50 mm. Specifically, Din and Dout can be 10 to 15 mm, 12 to 20 mm, 16 to 24 mm, 18 to 28 mm, 20 to 42 mm, 22 to 30 mm, 26 to 34 mm, 32 to 40 mm, 36 to 50 mm, 40 to 50 mm, etc.

[0067] In some feasible embodiments, the expandable implantable device 1 forms a waist 118 in its final state, the waist 118 being located between the first end 110 and the second end 112. The diameter Dmin of the waist is smaller than the diameter Din of the first end 110 and / or the diameter Dout of the second end 112, respectively. The diameter Dmin of the waist can be 10–40 mm. Further, the diameter Dmin of the waist can be 16–40 mm. Specifically, the diameter Dmin of the waist can be 10–20 mm, 10–22 mm, 10–24 mm, 10–30 mm, 10–34 mm, 10–38 mm, 16–20 mm, 16–22 mm, 16–24 mm, 16–34 mm, 23–30 mm, 28–38 mm, 32–40 mm, etc.

[0068] In some other feasible implementations, the diameter of the expandable implantable device 1 in its final state is substantially uniform in the axial direction, that is, in its final state it can be a structure with a cylindrical outline.

[0069] Furthermore, in some feasible embodiments, the expansion ratio of the diameter Dmin of the waist 118 in the final expanded state relative to the first expanded state (i.e., the diameter of the waist 118 in the first expanded state) is greater than the expansion ratio of the diameter Din or Dout of the first end 110 or the second end 112 in the final state relative to the first expanded state (i.e., the diameter DL or DR of the first end 110 or the second end 112 in the first expanded state). Specifically, in step S03, the expansion amplitude of the middle part (waist) of the expandable implantable device 1 is greater than the expansion amplitude of the end. Because in step S02, that is, during the expansion process of the first stage, the expansion amplitude of the end is greater than the expansion amplitude of the waist, for example, the position corresponding to the waist remains unchanged in the relative radial compression state in the first expanded state, or its expansion diameter is smaller than the expansion diameter of the end (forming a slope), to avoid excessive expansion of the end, the expandable implantable device 1 can also form a swing-like expansion in two different expansion stages, making the expansion shape of the support rod more flexible.

[0070] In some feasible implementations, the diameter ratio of the first or second end to the waist in the final state is 110% to 200%. Specifically, the diameter ratio can be 110%, 115%, 120%, 125%, 128%, 130%, 135%, 140%, 150%, 155%, 160%, 170%, 185%, etc. In the final state, the expandable implantable device 1 has a relatively larger diameter flare at one or both ends, allowing it to be positioned after implantation. A diameter ratio of 110% or higher can better serve the actual positioning function, making it more suitable for device positioning at target implantation sites with large-diameter lumens, such as heart valves, aorta, and pulmonary arteries. A diameter ratio of less than 200% ensures that the entire expandable implantable device 1 maintains the uniformity of the stent pattern and the smoothness of the overall contour during expansion to the final state, avoiding local sharp angle protrusions that could damage tissue.

[0071] In some feasible embodiments, in the final state, a second slope 400” is formed between the first end 110 or the second end 112 and the waist 118, and the angle δ of the second slope 400” is 5° to 50°. The definition of the angle δ can be referenced to the definition of the angle α, and will not be elaborated here. In some examples, the angle of δ is consistent with α; in other examples, the difference between the angle of δ and α is between 0% and 20%. In the two different radial expansion stages, the slope angles formed in the end regions differ by less than 20% or are approximately equal, so that the expansion amplitude of the end region (from the end to the connecting end) of the expandable implantable device 1 is relatively consistent in the axial direction during the expansion from the first expansion state to the final state. Thus, the end region in the final state can maintain the uniformity and smoothness of the end region in the first expansion state, and at the same time, it can maintain the axial positioning effect in this expansion stage, so that no axial displacement occurs during the entire expansion process.

[0072] In some embodiments, referring to Figures 2-7, the axial length Ls2 of the expandable implantable device 1 in the first expanded state is shortened to a certain extent relative to the axial length Ls1 in the radially compressed state, i.e., Ls2 < Ls1, and the axial length Ls3 in the final state is further reduced, i.e., Ls3 < Ls2 < Ls1. As an example, Ls1, Ls2, and Ls3 can be 8-150 mm, 7.9-145 mm, and 7.85-140 mm, respectively. Further, Ls1, Ls2, and Ls3 can also be 40-45 mm, 36-43 mm, and 28-36 mm, respectively. In some embodiments, the axial shortening rate (Ls1-Ls3) / Ls1*100% of the expandable implantable device 1 is 2%-30%. For stents with a final expansion diameter of 20 mm or more, the overall shortening rate can be controlled within 10%-30%.

[0073] When the expandable implantable device 1 has a leaflet 15, the distance Li between the first end 110 and the leaflet 15 in the radially compressed state can be equal to or unequal to the distance Lo between the second end 112 and the leaflet 15. Specifically, Li and Lo can be 9–20 mm. In other embodiments, Li = (Ls1-ls3) / 2 + Li', Lo = (Ls1-ls3) / 2 + Lo', where Li' and Lo' are the distances between the first end 110 and the leaflet 15 and the second end 112 and the leaflet 15, respectively, in the final expanded state. As an example, Li' and Lo' are 6–30 mm. In the final state, the axial span L of the second slope 400” is… L '、L RThe leaflets are 'smaller than Li' and 'Lo' respectively, which ensures that leaflet 15 is located in the flat expansion area rather than the slope area. This makes the axial cross-sectional shape of leaflet 15 uniform after expansion, and the joint between adjacent leaflets is good. It can close smoothly under the action of blood flow and avoid reflux.

[0074] It should be understood that the first radial expansion force and the second radial expansion force are not used to define the magnitude of the expansion force, but only to distinguish the forces applied to different ranges / sites of the expandable implantable device 1 at different stages of the expansion process. On the other hand, in some embodiments, the magnitudes of the first radial expansion force and the second radial expansion force may differ. For example, when the radial expansion force of the expandable implantable device 1 is provided by balloon expansion, the first radial expansion force may be provided by a balloon with a higher pressure, while the second radial expansion force may be provided by a balloon with a relatively lower pressure.

[0075] Although the expansion method of this application has been described above using a two-step expansion as an example, the expansion method of this application is not limited to two-step expansion. One or more discrete expansion steps can be added between the final state and the first expansion state.

[0076] It should be understood that the force applied to expand the expandable implantable device 1 can be either a positive or negative force. A positive force refers to the force applied to the expandable implantable device 1, from having no radial support for the blood vessel to having radial support. For example, if the expandable implantable device 1 is a balloon-expandable stent, it has virtually no elastic potential energy in its radially compressed state. It requires balloon expansion to apply an outward expansion force to the stent, causing it to undergo elastic and plastic deformation. After the balloon is removed, it can maintain a radially expanded state, thus providing sufficient radial support for the blood vessel. The expansion force provided to the stent by the balloon expansion is a positive force.

[0077] A negative force, relative to a positive force, applies an external force to cause the expandable implantable device 1 to "restore" its radial support force. For example, if the expandable implantable device 1 is a self-expanding stent, before implantation, the self-expanding stent is compressed to a smaller size for delivery to the diseased blood vessel via a catheter. In this state, the stent stores a large amount of elastic potential energy. When the stent reaches the target position, the sheath is retracted, and the stent is released from the sheath. The stored elastic potential energy, due to the loss of the sheath's constraint, is converted into the stent's expansion force, causing the stent to restore its radial support force to the blood vessel before compression. In other words, retracting the sheath is equivalent to applying a negative force to the stent, causing it to expand radially. The following description, with reference to Figures 8-19 in the specification, uses the application of a positive force to expand the expandable implantable device as an example to illustrate the expansion device of the present application embodiment.

[0078] Please refer to Figure 8, which is a schematic diagram of the overall structure of an expansion device for an expandable implantable device according to one embodiment of this application. It should be understood that the expansion device 2 of this application, in addition to the portion that directly provides radial expansion force, such as the balloon portion, also includes components or assemblies that constitute a complete delivery system, such as a catheter, an inflation port, and a sheath. The expansion device 2 includes a balloon catheter assembly 21 and a sheath assembly 23. The balloon catheter assembly 21 is at least partially slidably fitted within the sheath assembly 23 and can move forward as it enters the blood vessel. The balloon catheter assembly 21 includes a distal balloon portion 215. By inflating the balloon portion 215, a radial expansion force is applied to the expandable implantable device 1, causing the expandable implantable device 1 to expand radially under the action of the radial expansion force.

[0079] Please refer to Figures 10 and 11. After the balloon portion 215 carrying the expandable implantable device 1 is dislodged from the sheath assembly 23, the expandable implantable device 1 remains in a radially compressed state within the balloon portion 215. The specific structure and shape of the expandable implantable device 1 shown in Figure 11 are the same as those shown in Figure 2 (leaflets 15 are omitted). The balloon portion 215 of this embodiment can be used to implement the aforementioned expansion method. Specifically, the balloon portion 215 includes a first inner balloon 51, a second inner balloon 52, and an outer balloon 50. The first inner balloon 51 and the second inner balloon 52 are fitted inside the outer balloon 50. The two inner balloons are sealed to the catheter, meaning that when the inner balloons are inflated, the filling fluid will only fill the inner balloons and will not leak into the outer balloon. This ensures that the stent expansion proceeds in a predetermined phased manner, avoiding uncontrolled expansion of the stent due to uncontrolled flow of the filling fluid, which could lead to unintended stent expansion. When the expandable implantable device 1 is loaded in the balloon portion 215 in a radially compressed state, the balloon portion 215 is in an uninflated state, specifically it can be in a compressed / folded / collapsed / folded state.

[0080] Referring further to Figures 12-15, the balloon portion 215 of the expansion device 2 provides a first radial expansion force and a second radial expansion force to the expandable implantable device 1, causing the expandable implantable device 1 to expand stepwise according to the aforementioned expansion method. Specifically, the first inner balloon 51 and the second inner balloon 52 provide the first radial expansion force to the axially opposite first end 110 and second end 112 of the expandable implantable device 1 during inflation, increasing the diameters DL and DR of the first end 110 and second end 112 by 50% to 400% relative to the diameter Dcr of the expandable implantable device 1 in the radially compressed state. The outer balloon 50 provides the second radial expansion force to the expandable implantable device 1 during inflation, causing the expandable implantable device 1 to expand to its final state, where the diameter Din of the first end 110 and the diameter Dout of the second end 112 in the final state are larger than DL and DR. For simplicity, the diameter after balloon inflation is referred to as the balloon diameter, and unless otherwise specified, it generally refers to the value measured at the point of maximum balloon diameter after inflation.

[0081] As shown in Figures 12 and 13, when the first inner balloon 51 and the second inner balloon 52 are inflated, they force the outer balloon 50 covering them to expand to a certain extent, so that the overall outline of the balloon portion 215 is basically consistent with the outline of the two inner balloons after they are inflated. The expandable implantable device 1, which is initially held in the balloon portion 215, expands to the first expansion state due to the radial expansion force applied to it by the balloon portion 215. Because the expandable implantable device 1 and the balloon portion 215 are usually closely fitted, the outline of the expandable implantable device 1 in the first expansion state is relatively consistent with the outline of the balloon portion 215 corresponding to the holding position. Since the wall thickness of the expandable implantable device 1 remains essentially constant regardless of whether it is in a radially compressed or expanded state, and the wall thickness of each balloon is generally around tens to hundreds of micrometers, this application achieves a 50% to 400% increase in the diameter of the first end of the expandable implantable device relative to the radially compressed state by setting the ratio of the maximum diameter D21 of the first inner balloon 51 to the diameter of the connected catheter (such as the second catheter 2121) to 50% to 400%. Similarly, the ratio of the diameter of the second inner balloon 52 to the diameter of the catheter connected to the second inner balloon 52 is 50% to 400%. Furthermore, D21 is larger than the outer diameter of the sheath 232, and is preferably 1 / 4 to 1 / 2 of the maximum diameter D11 of the outer balloon. Specifically, D21 can be between 1.5 and 24 mm, and can be further set with reference to DL and DR.

[0082] In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, and the distance L20 between the distal end of the first inner balloon 51 and the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls1 of the expandable implantable device 1 in the radially compressed state. When the inner balloon is inflated, no inflation fluid enters the portion of the balloon portion 215 corresponding to the portion between the distal end of the first inner balloon 51 and the proximal end of the second inner balloon 52, so that the space between the first inner balloon 51 and the second inner balloon 52 is not inflated when the inner balloon is inflated, and the expandable implantable device 1 corresponding to this portion remains radially compressed. Simultaneously, because the axial center distance L20” between the first inner balloon 51 and the second inner balloon 52 is greater than or equal to Ls1, or the distance L20' between the proximal end of the first inner balloon 51 and the distal end of the second inner balloon 52 is greater than or equal to Ls1, the first end 110 to the first connecting end 114 and the second end 112 to the second connecting end 116 of the expandable implantable device 1 expand due to the expansion of the inner balloons, while the first connecting end 114 to the second connecting end 116 remains radially compressed. Specifically, L20≈Lcr, which can be 3~60mm. When the expandable implantable device... During the journey of device 1 from the intervention point to the target position, it maintains a radially compressed state on the balloon catheter. Since the balloon portion 215, located between the two inner balloons, consists of only one outer balloon wall, and this section is used to correspondingly press against the valve frame 10 with leaflets 15, the overall profile of the expandable implantable device 1 can be smaller, and the axial pressing shape more consistent. Furthermore, the diameter of the sheath surrounding it can also be smaller, making the delivery system easier to operate and applicable to a wider range of patients. In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52... The two inner balloons 52 are axially spaced apart, and the distance L20 from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls1 of the expandable implantable device 1 in the radially compressed state, and the expandable implantable device covers the area between the first inner balloon and the second inner balloon. In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, and the distance L20 from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls1 of the expandable implantable device 1 in the radially compressed state, and the expandable implantable device covers the area between the first inner balloon and the second inner balloon. The axial distance between the first inner balloon 51 and the second inner balloon 52 is less than the axial length Ls2 of the expandable implantable device 1 in the first expanded state. In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced, and the distance L20 from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls2 of the expandable implantable device 1 in the first expanded state, and the expandable implantable device covers the area between the first inner balloon and the second inner balloon.In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, and the distance L20 from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls3 of the expandable implantable device 1 in its final state. In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, and the distance L20 from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 (i.e., the axial distance between the first inner balloon 51 and the second inner balloon 52) is less than the axial length Ls3 of the expandable implantable device 1 in its final state, and the expandable implantable device covers the area between the first inner balloon and the second inner balloon.

[0083] In some feasible embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, so that the catheter is exposed between the distal end of the first inner balloon 51 and the proximal end of the second inner balloon 52. Therefore, when the inner balloons are inflated, the balloon portion 215 corresponding to the spacer between the two inner balloons does not bulge substantially, so that the middle portion of the expandable implantable device corresponding to this segment remains radially compressed. That is, by inflating the first inner balloon 51 and the second inner balloon 52, the range of application of the first radial expansion force is from the first end 110 of the expandable implantable device 1 to the first connecting end 114, and from the second end 112 to the second connecting end 116, so that the first connecting end 114 and the second connecting segment 116 of the expandable implantable device 1 remain radially compressed after the inner balloons are inflated.

[0084] In some feasible embodiments, the cone angle β of the second inner balloon is 20° to 120°. This allows the first slope 400 formed at both ends of the expandable implantable device 1 in the first expanded state to have an angle α greater than 0° and within 60°. It also allows the balloon wall to retract in a better contracted shape and return through the sheath when the filling fluid is removed and the balloon catheter is withdrawn. In other embodiments, the difference between the diameter of the first inner balloon 51 and the diameter of the second inner balloon 52 is less than 50%, i.e., the ratio of the difference between the diameters of the first inner balloon 51 and the second inner balloon 52 to the diameter of either the first inner balloon 51 or the second inner balloon 52 is less than 50%. This ensures more precise axial positioning throughout the expansion of the stent and avoids axial displacement.

[0085] When the outer balloon 50 is inflated, the two inner balloons can remain inflated. In some embodiments, the maximum diameter D21 of the first inner balloon or the maximum diameter D21' of the second inner balloon is equal to the maximum diameter D11 of the outer balloon 50. In some embodiments, the maximum diameter D11 of the external balloon 50 is 1.33 to 5 times the maximum diameter D21 of the first inner balloon or the maximum diameter D21' of the second inner balloon; in other embodiments, the maximum diameter D11 of the external balloon 50 is 1.5 to 4.5 times the maximum diameter D21 of the first inner balloon or the maximum diameter D21' of the second inner balloon, so that the end diameter of the expandable implantable device 1 in the final state is 1.5 to 4.5 times the end diameter in the first expanded state. It should be understood that the balloon diameter is the outer diameter (including the balloon wall thickness), and the stent diameter is the inner diameter (excluding the stent wall thickness). D11 can be set according to the expanded end diameter of the expandable implantable device 1, specifically within the range of 20 to 60 mm.

[0086] The inflated outer balloon 50 has a general shape resembling a peanut shell. Specifically, the outer balloon 50 includes a first portion 501 adjacent to the proximal end of the balloon portion 215, a second portion 502 adjacent to the distal end of the balloon portion 215, a third portion 503 connected to the first portion 501 and extending toward the distal end of the balloon portion 215, a fourth portion 504 connected to the second portion 502 and extending toward the proximal end of the balloon portion 215, and a waist portion 505 connecting the third and fourth portions. After the outer balloon is inflated, the cone angles θ of the first portion 501 and the second portion 502 are 40° to 80°, which is beneficial for the retraction of the balloon catheter. The single-sided oblique angle γ formed by the third portion 503 and the fourth portion 504 with the axial centerline of the balloon portion is basically equal to the oblique angle δ of the second slope 400", which is 5° to 50°, so that the expandable implantable device 1 forms the second slope 400 at both ends in the final state. As other examples, γ may be less than half the cone angle θ of the first segment 501 (or the second segment 502). It should be understood that these segments of the external balloon 50 are all part of the balloon wall of the external balloon 50.

[0087] The axial length L12 of the third section 503 and the axial length L13 of the fourth section 504 can be respectively related to the axial span L of the second slope 400". LThis allows for full utilization of the balloon length and avoids material waste. Furthermore, L12 or L13 equals (L10-L11) / 2. Correspondingly, the connection point between the first section 501 and the third section 503 is the first peak point of the change in the diameter of the external balloon 50, and the connection point between the second section 502 and the fourth section 504 is the second peak point of the diameter of the external balloon 50. The distance L10 between the two peak points can be: Ls3≤L10≤Ls1. Further, its specific parameter range can be 7.85~150mm, 28~36mm, etc., which can be set with reference to the corresponding parameters of the expandable implantable device 1, and will not be elaborated here. The length of the waist section 505 is greater than or equal to 0mm. When the length of the waist section 505 is 0mm, it is equivalent to the third section 503 and the fourth section 504 being directly connected. When the length of the waist 505 is greater than 0 mm, as shown in Figure 14, the axial cross-sectional profile of the waist 505 can be a straight line; the axial cross-sectional profile of the waist 505 can also be a smooth curve, corresponding to the expandable implantable device 1 that can be used to expand the waist 118 with a straight line or a smooth curve profile.

[0088] In some embodiments, the effective total length L1 of the balloon portion 215 can be set according to formula (3):

[0089] Ls1+2*D11 / tan(θ / 2)......(3).

[0090] Wherein, Ls1 is the length of the expandable implantable device 1 in a radially compressed state, specifically the stent gripping length; D11 is the maximum diameter of the external balloon 50 after inflation; θ is the cone angle of the external balloon 50, which is the cone angle of the first portion of the external balloon 50 mentioned above. It should be understood that the effective total length L1 of the balloon refers to the overall length of the inflatable portion of the external balloon 50, excluding the length of the portion that cannot be inflated due to adhesion to the catheter. In some specific examples, L1 can be 15–200 mm. Further, L1 can be 18–35 mm, 25–50 mm, 30–60 mm, 36–74 mm, 42–77 mm, 48–82 mm, 50–95 mm, 60–105 mm, 74–109 mm, 77–114 mm, 82–120 mm, 83–126 mm, 88–113 mm, 91–137 mm, 94–142 mm, 100–168 mm, 110–180 mm, 130–195 mm, etc. Within this length range, L1 allows various types of supports with an axial length Ls1 of 20–150 mm in a radially compressed state to implement the expansion method described in the preceding embodiments. In some examples, the θ angle ranges from 40° to 80°. Further variations include 42° to 48°, 45° to 50°, 47° to 55°, 52° to 60°, 55° to 64°, 58° to 66°, 62° to 74°, 65° to 78°, and so on. If the θ angle is too small (below 40°), the maximum expansion diameter D11 of the outer balloon 50 cannot be increased within a given effective total balloon length, thus failing to meet the expansion requirements of some large-diameter stents and limiting its application range. If the expansion diameter is increased by extending the balloon length, an excessively long balloon section affects the overall pushability of the balloon catheter assembly 21. Conversely, if the θ angle is too large, the balloon section 215 may exhibit poor retraction when the filling fluid is removed after the expandable implantable device 1 is expanded and implanted, making it impossible to retract through the sheath 232 and hindering the successful completion of the surgical procedure.

[0091] In some feasible implementations, D11 can be 4-8 mm longer than Dmin, so that the expandable implantable device 1 forms a structure with gently flared ends in the final state; L11 can be between one-third and two-thirds of L10, so that the leaflet 15 region located at the waist of the balloon 505 and the non-leaflet regions at both ends of the valve frame 10 form a better length ratio, so that when implanted into the native valve, the leaflet 15 is of moderate length and the flared regions at both ends of the valve frame 10 can also play a sufficient positioning role.

[0092] In some feasible embodiments, the length L21 of the first inner balloon 51 and the length L21' of the second inner balloon 52 can be 5–70 mm, and further, they can be 5–10 mm, 6–12 mm, 8–15 mm, 10–20 mm, 12–24 mm, 15–28 mm, 20–31 mm, 25–37 mm, 28–40 mm, 30–43 mm, 34–49 mm, 46–55 mm, 50–67 mm, etc. When leaflet 15 is present, the maximum value of L21 is (L1–Lv) / 2. The distance L24 from the proximal end of the outer balloon 50 to the proximal end of the first inner balloon 51 can be (L1–L10–2L21+10) / 2, ranging from 3.6 to 48 mm.

[0093] In some feasible embodiments, the inflation pressure of the first inner balloon 51 and the second inner balloon 52 is 6–10 atm, and the inflation pressure of the outer balloon is 1–2 atm. The second radial expansion force is generated by the expansion of the 1–2 atm balloon. The burst pressure of the first inner balloon 51 and the second inner balloon 52 is 12–16 atm, and the burst pressure of the outer balloon 50 is 5–8 atm. The first radial expansion force can be provided by the higher-pressure inner balloon, while the second radial expansion force can be provided by the relatively lower-pressure outer balloon 50, thereby providing sufficient force for the expansion of the expandable implantable device 1 in the first stage. In addition, the smaller inner balloon has a higher inflation pressure than the larger outer balloon, which helps to maintain pressure balance and improves the reliability of the balloon portion 215.

[0094] In some feasible embodiments, the external balloon 50, the first internal balloon 51, and the second internal balloon 52 are all semi-compliant balloons. The wall thickness of the first internal balloon 51 and the second internal balloon 52 is 50-80 μm; the wall thickness of the external balloon 50 at its maximum diameter after inflation is 60-120 μm, and the wall thickness at its waist is 100-160 μm.

[0095] Please refer to Figure 16, which is a schematic diagram of the expandable implantable device and expansion device according to another embodiment of this application. Compared with expandable implantable device 1, the main difference of expandable implantable device 1' is that the diameter of the final state is basically the same in the axial direction, that is, the outer contour after expansion is cylindrical. The corresponding expansion device 2' includes a first inner balloon 61 and a second inner balloon 62 similar to those in the aforementioned embodiment. The first inner balloon 61 and the second inner balloon 62 are located inside the outer balloon 60. The length, cone angle, spacing and other parameters of the two inner balloons can be referred to the aforementioned embodiment. The main difference between the outer balloon 60 and the outer balloon 50 in the aforementioned embodiment is that the outer balloon 60, after being inflated, presents a cylindrical structure with cone angles at both ends, that is, the oblique angle γ = 0°. The wall thickness of the outer balloon 60 can be basically equal along the axial direction. Other aspects can be referred to the aforementioned embodiment. For the expandable implantable device 1' whose final expanded state is a cylindrical structure, the inner balloon of the expansion device 2' in this embodiment first expands both ends of the expandable implantable device 1' to a certain extent, and then the outer balloon 60 is inflated to further expand the expandable implantable device 1'. This allows for time-segmented expansion of the expandable implantable device 1', buffering the expansion from both time and location dimensions. This effectively reduces unpredictable uneven expansion, local eversion, barbs, and other phenomena, resulting in a uniform and smooth final expansion shape of the expandable implantable device 1', providing better support for the implantation site and avoiding damage to the tissue.

[0096] The balloon section 215 of this application performs a first-stage expansion of the expandable implantable device 1 through the inner first inner balloon 51 and the second inner balloon 52, and performs a second-stage expansion using the outer balloon 50. The two expansion steps are discrete and performed independently, which not only allows the expandable implantable device 1 to be uniformly, smoothly and fully expanded at a precise target position in a preset manner, but also makes the operation simple and controllable, thus improving the safety of the entire system.

[0097] Referring again to Figures 8 and 9, the balloon catheter assembly 21 also includes a catheter hub 210, a catheter assembly 212, and a nasal cone 217. The proximal end of the catheter assembly 212 is connected to the catheter hub 210 and is connected to at least one input port through the catheter hub 210. As an example, there are three input ports, including a first port 201, a second port 202, and a third port 203. The first port 201 is used for the guidewire to enter and pass through the catheter assembly 212 to reach the distal end. The second port 202 and the third port 203 are used for injecting filling fluid into the balloon portion 215. Of course, depending on the different structural designs or functional requirements of the balloon portion 215 and the catheter assembly 212, the number of input ports can also be one, two, four, or more. The balloon portion 215 is fixed to the distal end of the catheter assembly and is used to provide radial expansion force to the expandable implantable device 1. The nasal cone 217 is connected to the distal end of the catheter assembly 212 and has a tapered structure with a diameter decreasing towards the distal end for guiding the balloon catheter assembly 21 forward within the blood vessel.

[0098] The sheath assembly 23 includes a handle 230, a sheath 232, a three-way valve 235, a connecting tube 233, and a rotary joint 236. The rotary joint 236 is connected to the proximal end of the handle 230 and is used to lock the relative position of the sheath assembly 23 and the balloon catheter assembly 21. The sheath 232 extends from the distal end of the handle 230 and covers the catheter assembly 212. The three-way valve 235 is connected to the handle 230 via the connecting tube 233 and communicates with the sheath 232. Flushing fluid, contrast agent, etc., can be injected into the lumen of the sheath 232 through the valve port of the three-way valve 235.

[0099] Please refer to Figures 8 and 9 for comparison. They show two states during the transcatheter implantation of the expandable implantable device 1. Figure 8 shows the expandable implantable device 1 loaded in the balloon catheter assembly 21 and covered by the sheath 232. Figure 9 shows the sheath 232 being withdrawn and the expandable implantable device 1 dislodging from the sheath 232 along with the balloon catheter assembly 21. The expandable implantable device 1 is held in place by the balloon catheter assembly 21, specifically in the balloon portion 215, and is covered and constrained by the sheath 232, wherein the distal end S of the sheath 232 abuts against the proximal end of the nasal cone portion 217. Guided by a pre-inserted guidewire (not shown), the dilator 2, together with the expandable implantable device 1 mounted thereon, is pushed into the blood vessel and advanced to the target position. Then, the sheath assembly 23 is withdrawn, so that the distal end S of the sheath 232 is retracted proximally relative to the balloon catheter assembly 21, and the balloon portion 215 is dislodged from the sheath 232. The balloon portion 215 can then be inflated to radially dilate the expandable implantable device 1.

[0100] In some feasible embodiments, the catheter assembly 212 may include a first catheter 2120 and a second catheter 2121, wherein the first catheter 2120 serves as an outer tube and the second catheter 2121 serves as an inner tube, the inner tube being fitted inside the outer tube and shorter than the outer tube. Please refer to Figure 19, where Figure 19(A) shows a schematic diagram of the structure of a catheter assembly according to one embodiment. The second catheter 2121, serving as the inner tube, includes two axially extending and mutually isolated lumens C1 and C2, wherein lumen C1 serves as a lumen through which a guidewire (not shown) passes. The proximal end of lumen C1 communicates with the first port 201, and its distal end communicates with a cavity within the nasal cone 217 so that the guidewire enters lumen C1 from the first port 201 and finally passes through the nasal cone 217. The lumen C2 can be used as an inflation cavity for the first inner balloon 51 and the second inner balloon 52. Two inflation holes h1 and h2 are formed in the wall of the second catheter 2121, corresponding to the first and second inner balloons 51 and 52 respectively. Both inflation holes h1 and h2 communicate with the lumen C2. The inflation fluid flowing through the lumen C2 can enter the first and second inner balloons 51 and 52 through the inflation holes h1 and h2 to achieve inflation and provide a first radial expansion force to the expandable implantable device 1. The proximal end of the lumen C2 also communicates with the second port 202 for connecting an injection device containing the inflation fluid. The annular lumen C0 formed between the inner wall of the first catheter 2120 and the outer wall of the second catheter 2121 can be used to inflate the outer balloon 50. The inflation fluid flowing through the lumen C0 can flow out from the distal end of the first catheter 2120 and enter the outer balloon 50. The proximal end of the lumen C0 communicates with the third port 203 for connecting an injection device containing the inflation fluid.

[0101] Figure 19(B) shows another modified embodiment of the catheter assembly 212, which is largely the same as the structure shown in 19(A). The connection relationships between the lumens C0, C1, and C2 and the ports and filling holes remain unchanged. The main difference is that a third catheter 2122 is sleeved between the first catheter 2120 and the second catheter 2121. A lumen C1 is formed inside the second catheter 2121, a lumen C2 is formed between the outer wall of the second catheter 2121 and the inner wall of the third catheter 2122, and a lumen C0 is formed between the outer wall of the third catheter 2122 and the inner wall of the first catheter 2120. Since both catheter assemblies use the same lumen (C2) to inflate the first inner balloon 51 and the second inner balloon 52, the two inner balloons are inflated in a single inflation step using an injection device, which is convenient to operate and can reduce the number of catheters contained in the catheter assembly, reduce the overall diameter of the catheter, and broaden the applicable scenarios for catheter-based interventional surgery. Of course, in other embodiments, the catheter assembly 212 may also be a three-lumen catheter, with the mutually isolated lumens C0 to C2 all formed within the same catheter.

[0102] Please refer to Figures 17 and 18. Figure 17 shows a schematic diagram of the overall structure of the dilation device 1 according to one embodiment of this application after the balloon portion 215 is fully inflated, while Figure 18 is a cross-sectional view along line AA in Figure 17. In some embodiments, the balloon catheter assembly 21 further includes a stainless steel tube 2125. One end of the stainless steel tube 2125 is fixed inside the catheter seat 210, and the other end covers the outside of the first catheter 2120 and a section of the proximal end of the first catheter 2120, which can serve to support and protect the balloon catheter assembly 21. Additionally, referring to Figure 14, the balloon catheter assembly 21 also includes one or more imaging rings. As an example, it may specifically include a first imaging ring 2170, a second imaging ring 2171, and a third imaging ring 2172, which are fixed around the outer wall of the second catheter 2121. The three imaging rings are axially spaced apart. The second imaging ring 2171 is located inside the first inner balloon 51, close to the axial center of the first inner balloon 51, and avoiding the filling hole h1. The third imaging ring 2172 is located inside the second inner balloon 52, close to the axial center of the second inner balloon 52, and avoiding the filling hole h2. The first imaging ring 2170 is located between the first inner balloon 51 and the second inner balloon 52, and preferably near the axial center of the outer balloon 50.

[0103] This application also provides a transcatheter implantation device system, as shown in Figures 8-9. The transcatheter implantation device system includes the dilation device 2 described in the foregoing embodiments and an expandable implantable device 1 mounted on the dilation device. The expandable implantable device 1 includes an axially opposed first end 110 and a second end 112. The dilation device includes a balloon portion 215, and the expandable implantable device 1 is mounted on the balloon portion 215. The balloon portion 215 includes a first inner balloon 51, a second inner balloon 52, and an outer balloon 50. The first inner balloon 51 and the second inner balloon 52 are fitted inside the outer balloon 50. When the first inner balloon... When the balloon 51 and the second inner balloon 52 are inflated, the expandable implantable device 1 expands from a radially compressed state to a first expanded state, and the diameters of the first end 110 and the second end 112 increase by 50% to 400% relative to the diameter of the expandable implantable device 1 in the radially compressed state; when the outer balloon 50 is inflated, the expandable implantable device 1 expands from the first expanded state to a final state, and the diameter of the first end 110 and / or the second end 112 in the final state is greater than the diameter in the first expanded state.

[0104] In some embodiments, the first inner balloon 51 and the second inner balloon 52 are axially spaced apart, the axial length of the expandable implantable device 1 is greater than the axial distance between the first inner balloon 51 and the second inner balloon 52, and the expandable implantable device 1 covers the area between the first inner balloon 51 and the second inner balloon 52.

[0105] In some embodiments, the expandable implantable device 1 is an artificial heart valve, which includes a valve frame 10 and leaflets 15 connected to the inside of the valve frame; the distance from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 is greater than the axial length of the leaflet 15 in the radially compressed state, and / or the distance from the distal end of the first inner balloon 51 to the proximal end of the second inner balloon 52 is greater than or equal to the axial length of the leaflet 15 in the final state.

[0106] Taking the expandable implantable device 1 as a pulmonary valve as an example, the exemplary operation procedure of the transcatheter implantation device system includes the following steps. For the sake of simplicity, routine steps such as device confirmation, disinfection, flushing, and angiography in interventional surgery are omitted.

[0107] 1) The expandable implantable device 1 is passed through the distal end of the balloon catheter assembly 21 and loaded into the balloon portion 215, wherein the first end and the second end of the expandable implantable device 1 are respectively aligned with the axial center of the first inner balloon 51 and the second inner balloon 52, and the balloon portion 215 is in a collapsed / folded state. At this time, the two ends of the expandable implantable device 1 have overlapping areas with the two inner balloons, while the leaflet 15 is between the two inner balloons, and the leaflet 15 has basically no overlap with the inner balloons;

[0108] 2) The expandable implantable device 1 fitted on the balloon catheter assembly 21 is pressed into a radially compressed state by means of instruments or manual operation, and the front end of the balloon catheter assembly 21 loaded with the expandable implantable device 1 is passed through the sheath assembly 23, so that the end of the sheath assembly 23 abuts against the nasal cone 217 of the balloon catheter assembly 21, forming a closed state as shown in Figure 8. At this time, the expandable implantable device 1 is located between the sheath 232 and the balloon catheter assembly 21 in a radially compressed state.

[0109] 3) Insert the above-mentioned transcatheter implantation device system into the blood vessel along the pre-placed guidewire from the prepared intervention point (femoral vein) until the target location (pulmonary valve) is reached;

[0110] 4) Keep the balloon catheter assembly 21 stationary and retract the sheath assembly 23 to expose the expandable implantable device 1. The catheter implantable device system is in the open position as shown in Figure 9. At this time, the expandable implantable device 1 is released from the sheath constraint.

[0111] 5) The filling fluid is injected into the first inner balloon 51 and the second inner balloon 52 through the syringe connected to the second port 202, so that the two inner balloons inflate and reach the nominal pressure. During the process of the two inner balloons being inflated and inflated, a first radial expansion force is generated, and the expandable implantable device 1 is locally radially expanded due to the radial expansion force provided by the two inner balloons, thus presenting a first expansion state.

[0112] 6) Maintain the aforementioned inflated state of the inner balloon, and inject filling fluid into the outer balloon 50 through the syringe connected to the third port 203, so that the outer balloon 50 inflates to the nominal pressure, and the outer balloon 50 inflates to generate a second radial expansion force, which is applied to the expandable implantable device 1 and causes it to expand to the final state.

[0113] 7) After confirming that the expandable implantable device 1 has expanded to the correct position, the filling fluid in the balloon is drawn back into the syringe by pulling back the syringe plunger, and the balloon 215 returns to its deflated state.

[0114] 8) Withdraw the balloon catheter assembly 21 and sheath assembly 23 from the blood vessel.

[0115] In some feasible embodiments, the materials of the outer balloon 50, the first inner balloon 51, and the second inner balloon 52 can be nylon, Pebax, polyethylene terephthalate, and polyurethane, etc.; their manufacturing process can include steps such as tube stretching, blowing, cutting, welding / bonding to the conduit, etc., wherein the first inner balloon 51 and the second inner balloon 52 can be formed simultaneously by blowing from a single tube, or they can be made separately by using separate tubes. The length of the welded portion of the first inner balloon 51 and the second inner balloon 52 can be about 1.5 to 3.5 mm at one end, for example, 2 mm, 2.5 mm, etc.; the length of the welded portion of the outer balloon 50 can be 1.5 to 5 mm at one end, for example, 2 mm, 3 mm, 3.5 mm, etc. When the first inner balloon 51 and the second inner balloon 52 are spaced apart, the welded portion at the distal end of the first inner balloon 51 and the welded portion at the proximal end of the second inner balloon 52 can be separated from each other without connection, that is, the balloon walls of the two inner balloons are completely separated; the welded portion at the distal end of the first inner balloon 51 and the welded portion at the proximal end of the second inner balloon 52 can also be connected, that is, there is a certain gap between the effective inflatable portions of the two inner balloons, but the balloon walls of the two are connected together, and the balloon wall located in the gap distance is tightly welded to the catheter and cannot be inflated.

[0116] As another aspect of this application, in order to accurately confirm the positioning of the expandable implantable device 1, angiography can be performed before positioning and when it is close to the target location. Contrast solution is injected into the sheath 232 through the three-way valve 235 and the connecting tube 233. The contrast solution flows out through the sheath 232 and mixes into the blood, thereby achieving angiography. Please refer to Figure 20, which is a partial cross-sectional structural schematic diagram of the expansion device according to another embodiment of this application. Its overall structure is roughly the same as the expansion device of the aforementioned embodiment, the main difference being that the sheath 232 includes multiple openings 2326. Specifically, the multiple openings 2326 are perforations that penetrate the sheath wall. When the expandable implantable device 1 is housed in the sheath 232, the position of the perforations is relatively located on the proximal side of the external balloon 50 (which is also the proximal end of the balloon portion 215). At this time, the distance of the perforation from the farthest end of the balloon catheter assembly 21 is greater than the distance from the proximal end of the balloon portion 215 to the farthest end of the balloon catheter assembly 21. In other words, these openings 2326 are axially offset from the balloon portion 215 and have a certain distance, or the openings are located outside the effective length of the balloon portion 215, so that the contrast agent can flow out through the openings 2326 and enter the blood vessel before reaching the balloon portion 215, fully mix with the blood near the openings 2326, and diffuse downstream of the blood vessel. This structure allows for direct angiography using the sheath before the expandable implantable device 1 is dislodged, eliminating the need to replace the guidewire. Furthermore, it enables angiography of the upstream and downstream vessels near the target location before the expandable implantable device 1 reaches that location, providing a clear view of the current vascular and lesion conditions and facilitating precise release of the expandable implantable device 1. Of course, the opening 2326 can also be used to diffuse therapeutic agents or other liquids into the lumen, which will not be elaborated upon here.

[0117] In other feasible embodiments, before sheath retraction, while the expandable implantable device 1 is still held in the sheath 232 in a radially compressed state, the first inner balloon 51 and the second inner balloon 52 are inflated to a certain extent, creating a "blocking" effect on the sheath 232. Although the deflated, folded balloon and the stent gripping the balloon can fill most of the lumen space of the sheath 232, some gaps are created by the folds of the balloon and the perforations of the stent, allowing the contrast agent to flow out of the end S of the sheath 232. Before detaching from the sheath 232, the inner balloons are inflated, and the portion of the first inner balloon 51 that proximally extends beyond the expandable implantable device 1 bulges, causing the balloon portion 215 to fit tightly against the inner wall of the sheath 232, blocking the path of the contrast agent to the end S. In this way, on the one hand, it can prevent some of the developing solution from overflowing from the opening at the end of the sheath 232 and force the developing solution to be concentrated and sprayed out from the opening 2326, increasing the developing solution output to the imaging target location and promoting thorough mixing of the developing solution with the blood, thereby improving the imaging effect upstream of the target location and facilitating the precise placement of the expandable implantable device at the target location. On the other hand, it can also prevent the developing solution from flowing into the expandable implantable device 1, avoiding contamination of the implantable device. Because the developing solution usually has a certain viscosity, it has not yet mixed with the blood when flowing in the sheath 232, and it is easy to cause contamination if it adheres to the expandable implantable device 1. Especially when the expandable implantable device 1 contains bioprosthetic leaflets, the developing solution adhering to the leaflets can also affect the smooth opening of the leaflets.

[0118] In some feasible embodiments, the sheath 232 includes a first segment 2321 and a second segment 2322, with the second segment 2322 located at a relatively distal end and having a larger diameter than the first segment 2321. The balloon portion 215 and the expandable implantable device 1 are primarily housed in the second segment 2322, and the larger diameter allows for the adaptation of expandable implantable devices 1 to different sizes and models. Additionally, an opening 2326 can be located in the second segment 2322, close to the first segment 2321. The opening 2326 can be distributed circumferentially and axially around the wall of the sheath 232, and its shape can be circular, square, elliptical, triangular, trapezoidal, or various other shapes.

[0119] In another feasible implementation, the expandable implantable device 1 can be a self-expanding stent, which can release the stent in a radially compressed state in stages through a structure such as a double-layer sheath, so that the stent changes from a radially compressed state to the aforementioned first expanded state, and then from the first expanded state to the final expanded state.

[0120] The specific implementation method of the expandable implantable device 1 of this application will be further described in detail below with reference to the embodiments and comparative examples.

[0121] Examples 1-6 and 27-29

[0122] The expandable implantable device 1 is an iron-based absorbable artificial pulmonary valve. The expandable implantable device 1 is expanded using the aforementioned expansion device 2. The balloon portion 215 is made of Pebax. Specific parameters of the expandable implantable device 1 in different embodiments 1-6 and 27-29 are shown in Table 1 below, and specific parameters of the expansion device 2 corresponding to embodiments 1-6 and 27-29 are shown in Table 2 below. The expandable implantable device 1 in embodiment 1 corresponds to the expansion device 2 in embodiment 1, the expandable implantable device 1 in embodiment 2 corresponds to the expansion device 2 in embodiment 2, and so on. In Tables 1 and 2, unless otherwise specified, the unit for each parameter is mm (millimeters). When the expandable implantable device 1 is in its first expansion state and final state, visual observation shows that the expandable implantable devices 1 in embodiments 1-6 and 27-29 are all uniformly expanded with smooth contours, and no end-stent eversion, barbs, or uneven patterns are observed.

[0123] Table 1

[0124] Table 2

[0125] Examples 7-14 and 30

[0126] The expandable implantable device 1' is a cobalt-chromium alloy coronary stent, employing the expansion device 2' shown in Figure 16. Specific parameters of the expandable implantable device 1' in different embodiments 7-14 and 30 are shown in Table 3 below, and the corresponding parameters of the expansion device 2' are shown in Table 4 below. When the expandable implantable device 1' is in its first expansion state and final state, visual observation shows that the expandable implantable devices 1' in embodiments 7-14 and 30 all expand uniformly, have smooth contours, and do not exhibit end stent eversion, barbs, uneven patterns, or other defects.

[0127] Table 3

[0128] Table 4

[0129] Examples 15-20 and 31

[0130] The expandable implantable device 1' is an iron-based peripheral vascular stent. The expandable implantable device 1' is expanded using the aforementioned expansion device 2'. Specific parameters of the expandable implantable device 1' in different embodiments 15-20 and 31 are shown in Table 5 below, and the corresponding parameters of the expansion device 2' are shown in Table 6 below. When the expandable implantable device 1' is in its first expansion state and final state, visual observation shows that the expandable implantable devices 1' in embodiments 15-20 and 31 are all uniformly expanded with smooth contours, and no end-stent eversion, barbs, or uneven patterns are observed.

[0131] Table 5

[0132] Table 6

[0133] Examples 21-26 and 32-33

[0134] The expandable implantable device 1' is an iron-based abdominal aortic stent. The expandable implantable device 1' is expanded using the aforementioned expansion device 2'. Specific parameters of the expandable implantable device 1' in different embodiments 21-26 and 32-33 are shown in Table 7 below, and the corresponding parameters of the expansion device 2' are shown in Table 8 below. When the expandable implantable device 1' is in its first expansion state and final state, visual observation shows that the expandable implantable devices 1' in embodiments 21-26 and 32-33 are all uniformly expanded with smooth contours, and no end-stent eversion, barbs, or uneven patterns are observed.

[0135] Table 7

[0136] Table 8

[0137] Comparative Examples 1-5

[0138] Expandable implantable device 1 is an iron-based absorbable artificial pulmonary valve. The expected expansion structure is similar to that shown in Figure 4. The expansion device shown in Figure 21 is used, in which the balloon part 215' is a single balloon. The one-step expansion method is used to expand the iron-based absorbable artificial pulmonary valve from the gripped state to the final state in one go. The parameters of different specifications of iron-based absorbable artificial pulmonary valves and their corresponding balloons and expansion effects are shown in Table 9. It can be seen that different specifications of devices exhibit different unsatisfactory expansion patterns after expansion with a single balloon.

[0139] Table 9

[0140] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Rather, any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for expanding an expandable implantable device, characterized in that, include: A first radial expansion force is applied to the expandable implantable device, causing the expandable implantable device to present a first expanded state, wherein the diameter of the axially opposite first end and second end of the expandable implantable device in the first expanded state is increased by 50% to 400% relative to the diameter of the expandable implantable device in the radially compressed state. A second radial expansion force is applied to the expandable implantable device, causing the expandable implantable device to expand from the first expansion state to a final state, wherein the diameter of the first end and / or the second end in the final expansion state is greater than the diameter in the first expansion state.

2. The method according to claim 1, characterized in that, The first radial expansion force is applied from the first end to the first connecting end and from the second end to the second connecting end, with the first connecting end and the second connecting end located between the first end and the second end.

3. The method according to claim 2, characterized in that, The axial distance between the first connecting end and the second connecting end is 10% to 80% of the axial length of the expandable implantable device in the radially compressed state; The axial distance between the first connecting end and the second connecting end is 3mm to 60mm, and the axial length of the expandable implantable device in the radially compressed state is 20mm to 150mm.

4. The method according to claim 2 or 3, characterized in that, The expandable implantable device is an artificial heart valve, which includes a valve frame and leaflets connected to the inside of the valve frame. The leaflets are located in the region between the first connecting end and the second connecting end. The axial distance between the first connecting end and the second connecting end is 5mm to 30mm, and the axial length of the expandable implantable device in the radially compressed state is 20mm to 60mm.

5. The method according to any one of claims 2-4, characterized in that, In the first expanded state, a first slope is formed between the first end and the first connecting end, and the slope angle of the first slope is greater than 0° and less than or equal to 60°.

6. The method according to any one of claims 2-5, characterized in that, When in the first expanded state, the diameter of the expandable implantable device gradually decreases from the first end to the first connecting end, and / or the diameter of the expandable implantable device gradually decreases from the second end to the second connecting end; The first connecting end is located between the axial center of the expandable implantable device and the first end, and the second connecting end is located between the axial center of the expandable implantable device and the second end. The diameter of the expandable implantable device in the first expanded state remains unchanged relative to the diameter in the radially compressed state when it is located between the first connecting end and the second connecting end.

7. The method according to any one of claims 1-6, characterized in that, In the first expanded state, the difference between the diameter of the first end and the diameter of the second end is less than 50% of the diameter of the first end in the first expanded state.

8. The method according to any one of claims 1-7, characterized in that, The diameter of the first end in the final state is 1.5 to 4.5 times the diameter of the first end in the first expanded state; and / or the diameter of the second end in the final state is 1.5 to 4.5 times the diameter of the second end in the first expanded state.

9. The method according to any one of claims 1-8, characterized in that, The expandable implantable device forms a waist in the final state, the waist being located between the first end and the second end, and the diameter of the waist being smaller than the diameter of the first end and / or the diameter of the second end, respectively; or the diameter of the expandable implantable device in the final state is substantially the same in the axial direction. The diameter of the waist relative to the first expanded state is increased at a rate greater than the diameter of the first end or the second end in the final state relative to the first expanded state; and / or the diameter ratio of the first end or the second end to the waist in the final state is 110% to 200%.

10. The method according to claim 9, characterized in that, In the final state, a second slope is formed between the first end or the second end and the waist, and the slope angle of the second slope is 5° to 50°.

11. An expansion device for an expandable implantable device, characterized in that, The expansion device includes: The catheter assembly includes at least one catheter; The balloon portion is connected to and fixed to the distal end of the catheter assembly and can accommodate the expandable implantable device. The balloon portion includes a first inner balloon, a second inner balloon, and an outer balloon. The first inner balloon and the second inner balloon are fitted inside the outer balloon. The first inner balloon and the second inner balloon are used to provide a first radial expansion force to the expandable implantable device when inflated. The outer balloon is used to provide a second radial expansion force to the expandable implantable device when inflated so that the expandable implantable device expands to its final state.

12. The expansion device according to claim 11, characterized in that, When the dilation device is in the inflated state, the maximum diameter of the first inner balloon or the second inner balloon is equal to the maximum diameter of the outer balloon. or The maximum diameter of the outer balloon is 1.5 to 4.5 times the maximum diameter of the first inner balloon, and / or the maximum diameter of the outer balloon is 1.5 to 4.5 times the maximum diameter of the second inner balloon.

13. The expansion device according to claim 11 or 12, characterized in that, The first inner balloon and the second inner balloon are axially spaced apart, and the distance from the distal end of the first inner balloon to the proximal end of the second inner balloon is less than the axial length of the expandable implantable device in the radially compressed state; the axial center distance between the first inner balloon and the second inner balloon is greater than or equal to the axial length of the expandable implantable device in the radially compressed state, or the distance from the proximal end of the first inner balloon to the distal end of the second inner balloon is greater than or equal to the axial length of the expandable implantable device in the radially compressed state; The distance between the distal end of the first inner balloon and the proximal end of the second inner balloon is 3mm to 60mm.

14. The expansion device according to any one of claims 11-13, characterized in that, The cone angle of the first inner balloon and / or the cone angle of the second inner balloon are 20° to 120°; and / or the difference between the diameter of the first inner balloon and the diameter of the second inner balloon is less than 50%.

15. The expansion device according to any one of claims 11-14, characterized in that, The external balloon includes a first portion adjacent to the proximal end of the balloon portion and a second portion adjacent to the distal end of the balloon portion. After the external balloon is inflated, the cone angles of the first portion and the second portion are 40° to 80°, respectively. The external balloon further includes a third portion and a fourth portion, wherein the third portion is connected to the first portion and extends distally toward the balloon portion, and the fourth portion is connected to the second portion and extends proximally toward the balloon portion, and the single-sided oblique angle formed by the third portion and the fourth portion with the axial centerline of the balloon portion is less than half of the cone angle of the first portion or the second portion; The external balloon further includes a waist section, which is connected between the third section and the fourth section. The length of the waist section is greater than or equal to 0 mm, and the axial cross-sectional profile of the waist section is a smooth curve or a straight line.

16. The expansion device according to any one of claims 11-15, characterized in that, The inflation pressure of the first inner balloon and the second inner balloon is greater than the inflation pressure of the outer balloon, and / or the burst pressure of the first inner balloon and the second inner balloon is greater than the burst pressure of the outer balloon; Inflate the first inner balloon and the second inner balloon to their inflated state and reach their nominal pressures; maintain the first inner balloon and the second inner balloon in the inflated state, and inflate the outer balloon to its nominal pressure.

17. The expansion device according to any one of claims 11-16, characterized in that, The dilation device further includes a sheath through which the balloon portion and the catheter assembly slidably pass. The sheath has a plurality of openings in its wall. When the balloon portion is contained in the sheath in a compressed state, the plurality of openings are located on the proximal side of the balloon portion and beyond the effective length of the balloon portion. The openings are used to diffuse contrast agents, therapeutic agents, or other liquids to the outside of the sheath. The first inner balloon and the second inner balloon are at least partially inflated and block the sheath. The catheter assembly includes a first catheter and a second catheter, with the first catheter sleeved over the second catheter. The external balloon is inflated through the first catheter, and the first internal balloon and the second internal balloon are inflated through the same inflation cavity of the second catheter.

18. A transcatheter implantation device system, characterized in that, The device includes an expansion device and an expandable implantable device mounted on the expansion device. The expandable implantable device includes a first end and a second end that are axially opposite each other. The expansion device includes a balloon portion, and the expandable implantable device is mounted on the balloon portion. The balloon portion includes a first inner balloon, a second inner balloon, and an outer balloon, with the first inner balloon and the second inner balloon fitted inside the outer balloon. When the first inner balloon and the second inner balloon are inflated, the expandable implantable device expands from a radially compressed state to a first expanded state, and the diameters of the first end and the second end are increased by 50% to 400% relative to the diameter of the expandable implantable device in the radially compressed state. When the outer balloon is inflated, the expandable implantable device expands from the first expanded state to a final state, and the diameter of the first end and / or the second end in the final state is larger than the diameter in the first expanded state.

19. The system according to claim 18, characterized in that, The first inner balloon and the second inner balloon are axially spaced apart, the axial length of the expandable implantable device is greater than the axial distance between the first inner balloon and the second inner balloon, and the expandable implantable device covers the area between the first inner balloon and the second inner balloon.

20. The system according to claim 18 or 19, characterized in that, The expandable implantable device is an artificial heart valve, which includes a valve frame and leaflets connected to the inside of the valve frame; the distance from the distal end of the first inner balloon to the proximal end of the second inner balloon is greater than the axial length of the leaflet in the radial compression state, and / or the distance from the distal end of the first inner balloon to the proximal end of the second inner balloon is greater than or equal to the axial length of the leaflet in the final state.

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