Independent expandable rotary-cut stent and processing technology thereof

Abstract

The invention discloses an independent expandable rotary-cut stent and a processing technology thereof.The expandable rotary-cut stent comprises a head end connecting assembly, a rotary-cut section and a tail end control section, and the head end connecting assembly can be matched with the head end of a balloon dilatation catheter; the rotary cutting section is formed by cutting nickel-titanium metal, and local focusing pressure can be formed after the rotary cutting section is expanded; and the tail end control section can realize dynamic cutting of vasculopathy by pushing, pulling and stretching the stent. The balloon can perform dynamic rotary cutting operation in the blood vessel to treat the narrow lesion after being matched with the balloon, so that the cutting effect on the lesion is enhanced; the rotary cutting section is flexibly sleeved on the surface of the balloon and can be controlled to relatively slide on the balloon through the tail end, so that the damage to the balloon is reduced; the tail end control section adopts the cutting wire design, the overall size of the balloon is reduced after matching, the delivery performance is enhanced, the size of the delivery section of the balloon is hardly increased, and the balloon can enter narrow lesions more easily.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an independent expandable rotary cutting stent and a processing technology thereof. Background Art

[0002] Percutaneous transluminal angioplasty (PTA) uses interventional devices such as balloon catheters and stents, and adopts balloon dilation technology or implanted stents to open or maintain vascular patency in various vascular stenosis and occlusions. This method has minimal trauma, low surgical risk, and significant efficacy.

[0003] Conventional balloons require high pressure to fully expand, and there are risks of spiral tearing and loss of lumen geometry during expansion, which is low in safety. The blade of the cutting balloon cuts along the longitudinal direction of the blood vessel wall during expansion, reducing the expansion pressure, irregular tearing and severe dissection. However, there is a risk of detachment between the cutting piece and the balloon.

[0004] The cutting parts on the existing scored balloons reduce the overall flexibility of the balloon, making it difficult to pass through the bends of blood vessels. After the balloon is expanded, it cannot completely return to its original shape, making it not smooth when withdrawn. If the height of the cutting knife of the cutting balloon is too high, the outer diameter of the balloon will be too large and it will not be able to pass through small blood vessels or severely narrowed lesions. The blades of the existing scored balloons are unevenly arranged, causing the blood vessels to be subjected to greater force in the direction of contact with the blades, which is prone to tearing. In addition, when the balloon expands radially, since the axial ends of the blades remain fixed, when the stent expands radially, tension will be generated in the axial direction, which will hinder the expansion.

[0005] Existing cutting balloons and scoring balloons are more expensive than ordinary balloon dilatation catheters; and the function of a single balloon dilatation catheter is relatively simple and difficult to adapt to surgical needs in different environments. Summary of the invention

[0006] The purpose of the present invention is to provide an independent expandable rotary cutting stent and its processing technology, aiming to overcome the safety problems in the use of cutting balloons and scoring balloons, and at the same time provide a new application mode for ordinary balloon dilatation catheters.

[0007] The present invention is implemented by adopting the following technical scheme: an independent expandable rotary cutting stent, comprising a head end connection component, a rotary cutting section and a tail end control section connected in sequence, the head end connection component can be connected to the head end of a balloon dilatation catheter, and the tail end control section can be connected to the tail end of the balloon dilatation catheter.

[0008] Furthermore, the rotary cutting section is composed of a locking section and a cutting section. The rotary cutting section of the expandable rotary cutting stent is compressed or stretched by circumferential twisting before assembly and has elastic potential energy.

[0009] Furthermore, after expansion, the rotary cutting segment can be controlled by the tail end control segment to be stretched or compressed to release elastic potential energy and perform rotary cutting on the lesion.

[0010] Furthermore, the rotary cutting section and the balloon are interference fit, and the balloon supports and straightens the rotary cutting section of the expandable rotary cutting stent, so that the axial displacement of the rotary cutting section is controllable during twisting.

[0011] Furthermore, the length ratio of the locking section and the cutting section is 4:(0-13), and the overall length is at least 50 mm longer than the length of the balloon dilatation catheter.

[0012] Furthermore, the cutting segment is a cutting component made of nickel-titanium metal cutting, which forms a spiral shape after expansion, and the rod width of the cutting component is 0.4~0.8mm.

[0013] Furthermore, any cross section of the thin rod of the cutting assembly perpendicular to the axial direction is a triangle, one side of which is the inner surface of the cylindrical hollow tube, which contacts the surface of the balloon and has edges on the outer side.

[0014] Furthermore, the tail end control section is a cutting wire made of the same material as the stent and has a buckle, and the tail end control section is connected to the tail end of the balloon dilatation catheter through the buckle.

[0015] Furthermore, a physical locking structure is provided inside the head end connection component, the head end connection component is wrapped by a polymer material, and the head end connection component is connected to the rotary cutting section by hot air welding.

[0016] A process for processing an independent expandable rotary-cut stent, characterized by comprising the following steps: Step 1: laser cutting of the rotary cutting section of the expandable rotary cutting stent; Step 2: Pickling and polishing of the peeled segment of the expandable peeled stent: After laser cutting, the expandable peeled stent is placed in a slag solution containing pure phosphoric acid and sulfuric acid (10:3) for ultrasonic removal of slag for 4-8 minutes, the water temperature is controlled at 50°C, and then placed in anhydrous ethanol for ultrasonic cleaning for 5-15 minutes. Repeat 3-6 times to remove residual oxidation products on the surface and then blow dry with compressed air; Step 3, welding the peeling section of the expandable peeling stent to the head end connection component and the tail end control section; Step 4: Bond the tail end control section to the buckle.

[0017] The independent expandable rotary cutting stent and its processing technology described in the present invention have the following beneficial effects: Dynamic cutting: The tail end control section releases the elastic potential energy of the rotary cutting section by pushing and pulling the cutting wire to achieve precise rotary cutting.

[0018] Improved flexibility: The stent is sleeved on the outside of the balloon, and the overall outer diameter is small, allowing it to pass through narrow lesions.

[0019] Safe withdrawal: The superelasticity of the nickel-titanium material allows the stent to retract and wrap around the balloon, making it easy to withdraw.

[0020] Uniform cutting: The locking section of the rotary cutting section adopts a spatial dense mesh structure to avoid blood vessel tearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0022] Figure 1 is an overall schematic diagram of the expandable rotary cutting stent of the present invention; Figure 2 It is a schematic structural diagram of the rotary cutting section of the expandable rotary cutting stent of the present invention; Figure 3 It is an expanded view of the locking section of the present invention along the circumferential direction; Figure 4 It is a partial enlarged expansion diagram of the locking section of the present invention; Figure 5 It is a schematic diagram of the structure of the rotary cutting section of the expandable rotary cutting stent of the present invention before releasing the elastic potential energy; Figure 6 It is a schematic diagram of the structure of the rotary cutting section of the expandable rotary cutting stent of the present invention after releasing the elastic potential energy; In the figure, 1-head end connecting component, 2-rotating cutting section, 3-tail end control section, 4-locking section, 5-cutting section. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] like Figure 1-6As shown, an independent expandable rotary cutting stent and its processing technology include a head end connection component 1, a rotary cutting section 2 and a tail end control section 3, wherein the head end connection component 1 can be connected to the head end of a balloon dilatation catheter, and the tail end control section 3 can be connected to the tail end of the balloon dilatation catheter.

[0026] The rotary cutting section 2 of the expandable rotary cutting stent is composed of a locking section 4 and a cutting section 5. The rotary cutting section 2 of the expandable rotary cutting stent is compressed or stretched by circumferential twisting before assembly and has elastic potential energy. After expansion, the rotary cutting section 2 can be controlled by the tail end control section 3 to stretch or compress to release the elastic potential energy and perform rotary cutting on the lesion. After the rotary cutting section 2 and the balloon are interference-fitted, the balloon supports and straightens the rotary cutting section of the expandable rotary cutting stent, so that its axial displacement is controllable during twisting.

[0027] The length ratio of the locking section 4 to the cutting section 5 is 4:(0-13), and the overall length is at least 50 mm longer than the length of the balloon dilatation catheter. The locking section 4 is a cylindrical hollow tube, and the cutting section 5 is a cutting assembly made of nickel-titanium metal cutting, which forms a double-helix rod-shaped structure after expansion, and the rod width of the cutting assembly is 0.4-0.8 mm.

[0028] The cross section of any part of the spiral thin rod of the cutting assembly perpendicular to the axial direction is a triangle, one side of which is the inner surface of the cylindrical hollow tube, which contacts the surface of the balloon, and has edges on the outer side.

[0029] The head end connection component 1 of the expandable rotary cutting stent has a physical locking structure inside, the head end connection component 1 is wrapped by a polymer material, and the head end connection component 1 is connected to the locking section 4 by hot air welding.

[0030] The tail end control section 3 of the expandable rotary cutting stent has a cutting wire made of the same material as the stent and has a buckle, and the tail end control section 3 is connected to the tail end of the balloon dilatation catheter through the buckle.

[0031] A process for manufacturing an expandable rotary-cut stent comprises the following steps: Step 1: Laser cutting of the exfoliated section of the expandable exfoliated stent: 3D laser cutting can be used to process the spiral section, and the laser cutting angle can be 30-60°; Step 2: Pickling and polishing of the peeled section of the expandable peeled stent: After laser cutting, the expandable peeled stent is placed in a slag solution containing pure phosphoric acid and sulfuric acid (10:3) for ultrasonic removal of slag for 4-8 minutes, the water temperature is controlled at 50°C, and then placed in anhydrous ethanol for ultrasonic cleaning for 5-15 minutes. Repeat 3-6 times to remove residual oxidation products on the surface and then blow dry with compressed air; Step 3: Weld the expansible peeling stent peeling section to the head end connection component and the tail end control section. Use TPU or PEBAX round tube to hot-melt weld the expansible peeling stent peeling section and the head end connection component (material can be PP, PEBAX, PE, etc.) to complete the assembly. Use laser welding to weld the expansible peeling stent peeling section and the tail end connection section cutting wire.

[0032] Step 4: Bond the tail end control section to the buckle. Use photosensitive glue, instant glue, etc. to bond the handle buckle (material can be PP, PE, PC, ABS, etc.) to the tail of the cutting wire of the tail end control end.

[0033] Based on the above technical solution, the embodiments of the present invention can at least produce the following technical effects: The present invention provides an independent expandable rotary cutting stent, which includes a head end connecting component, a rotary cutting section and a tail end control section. The head end connecting component can cooperate with the head end of a balloon dilatation catheter; the rotary cutting section is cut from nickel-titanium metal and can form local focused pressure after expansion; the tail end control section can achieve dynamic cutting of vascular lesions by pushing, pulling and retracting the stent.

[0034] The present invention provides an independent expandable rotary cutting stent. After the expandable stent is sleeved, the overall size of the balloon is reduced, the radius is reduced, and the tail end control section adopts a cutting wire design. After cooperation, the size of the balloon delivery section is almost not increased, making it easier to enter small lesions, and the flexibility is increased, making it easier to enter small lesions.

[0035] The present invention provides an independent expandable rotary cutting stent, wherein the rotary cutting segment of the expandable rotary cutting stent is made of nickel-titanium material, which has the property of superelasticity. After the expansion force is removed, the force of the expandable rotary cutting stent made of nickel-titanium material to restore its original state can wrap the balloon again, promote the retraction of the balloon segment, and make the withdrawal smoother.

[0036] The present invention provides an independent expandable rotary cutting stent, wherein the surface of the expandable rotary cutting stent in contact with the balloon is a plane, and the corresponding outer side has a sharp angle, so that the stent can be more easily cut into the narrow part of the blood vessel without damaging the balloon, thereby reducing the risk of surgery.

[0037] The present invention provides an independent expandable rotary cutting stent. The locking section of the expandable rotary cutting stent can use a space dense mesh structure. The circumferentially surrounding and axially extended blade mesh can make the effect of cutting the narrow blood vessel more uniform, less likely to tear the blood vessel, and effectively avoid the risk of causing dissection. At the same time, it can play a fixing role to prevent the position of the cutting section from changing during rotary cutting.

[0038] The present invention provides an independent expandable rotary cutting stent, wherein the buckle of the tail end control end section of the expandable rotary cutting stent can be displacement-controlled, so that after the balloon is expanded, the stent has relative displacement with the balloon on the surface of the balloon, thereby rotary cutting the lesion.

[0039] The present invention provides an independent expandable rotary cutting stent. The buckle of the tail end control end section of the expandable rotary cutting stent has gear selection, which can accurately control the position and distance of the rotary cutting to prevent damage to healthy blood vessels.

[0040] The above embodiments describe the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the changes and modifications made by those skilled in the art shall be within the scope of protection of the appended claims of the present invention without departing from the spirit and scope of the present invention.

Claims

1. An independent expandable rotary cutting stent, characterized in that: It comprises a head end connection component (1), a rotary cutting section (2) and a tail end control section (3) which are connected in sequence; the head end connection component (1) can be connected to the head end of a balloon dilatation catheter, and the tail end control section (3) can be connected to the tail end of the balloon dilatation catheter.

2. The independent expandable rotary cutting stent according to claim 1, characterized in that: The rotary cutting section (2) is composed of a locking section (4) and a cutting section (5); the rotary cutting section (2) of the expandable rotary cutting stent is compressed or stretched by circumferential twisting before assembly, and has elastic potential energy.

3. The independent expandable rotary cutting stent according to claim 2, characterized in that: After expansion, the rotary cutting section (2) can be controlled by the tail end control section (3) to be stretched or compressed to release elastic potential energy and perform rotary cutting on the lesion.

4. The independent expandable rotary cutting stent according to claim 1, characterized in that: The rotary cutting section (2) is interference fit with the balloon, and the balloon plays a supporting and straightening role on the rotary cutting section (2) of the expandable rotary cutting stent, so that the axial displacement of the rotary cutting section (2) is controllable when it is twisted.

5. The independent expandable rotary cutting stent according to claim 2, characterized in that: The length ratio of the locking section (4) to the cutting section (5) is 4:(0-13), and the overall length is at least 50 mm longer than the length of the balloon dilatation catheter.

6. The independent expandable rotary cutting stent according to claim 2, characterized in that: The cutting section (5) is a cutting component made by cutting nickel-titanium metal, which forms a spiral rod-shaped structure after expansion, and the rod width of the cutting component is 0.4-0.8 mm.

7. The independent expandable rotary cutting stent according to claim 6, characterized in that: The cross section of any part of the rod-shaped structure of the cutting assembly perpendicular to the axial direction is a triangle, one side of which is the inner surface of the cylindrical hollow tube, which contacts the surface of the balloon, and has edges on the outer side.

8. The independent expandable rotary-cut stent according to claim 1, characterized in that: The tail end control section (3) is a cutting wire made of the same material as the stent and provided with a buckle, and the tail end control section (3) is connected to the tail end of the balloon dilatation catheter via the buckle.

9. The independent expandable rotary cutting stent according to claim 1, characterized in that: The head end connection component (1) has a physical locking structure inside, the head end connection component (1) is wrapped by a polymer material, and the head end connection component (1) is connected to the rotary cut section (2) by hot air welding.

10. A process for producing an independent expandable rotary-cut stent according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: laser cutting of the rotary cutting section of the expandable rotary cutting stent; Step 2: Pickling and polishing of the peeled segment of the expandable peeled stent: After laser cutting, the expandable peeled stent is placed in a slag solution containing pure phosphoric acid and sulfuric acid (10:3) for ultrasonic removal of slag for 4-8 minutes, the water temperature is controlled at 50°C, and then placed in anhydrous ethanol for ultrasonic cleaning for 5-15 minutes. Repeat 3-6 times to remove residual oxidation products on the surface and then blow dry with compressed air; Step 3, welding the peeling section of the expandable peeling stent to the head end connection component and the tail end control section; Step 4: Bond the tail end control section to the buckle.

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