Guiding extension catheter
By using a stainless steel braided mesh reinforcement layer and an integrally molded semi-circular push rod design in the guide extension catheter, the problems of excessive hardness in the catheter transition connection section and easy breakage during welding are solved, improving the catheter's flexibility and coaxiality, and enhancing instrument compatibility and surgical safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2026-04-14
AI Technical Summary
Existing guiding extension catheters have excessive rigidity at the transition connection section, resulting in poor bending performance and easy breakage of the welded connection, affecting coaxiality and safety, and potentially causing vascular damage to patients.
Stainless steel braided mesh is used as the reinforcing layer. The push rod and the imaging ring are integrally molded and designed as a semi-circular arc. The outer layer is coated with a hydrophilic coating. The push rod and the imaging ring are bonded with UV glue to avoid welding and maintain a large inner lumen and good coaxiality of the catheter.
It improves the flexibility and coaxiality of the catheter, reduces the risk of push rod breakage, enhances instrument compatibility, simplifies surgical procedures, and reduces the risk of damage to blood vessels.
Smart Images
Figure CN224113103U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of medical device technology, and more specifically, to a guiding extension catheter. Background Technology
[0002] A guide extension catheter is an auxiliary device used in percutaneous coronary intervention (PCI). It is a coaxial "mother-daughter" catheter system that can be used for deep vascular insertion and device delivery, and provides active support through a long, flexible tubular distal end.
[0003] The guiding extension catheter has three main clinical applications: 1) In cases of coronary artery ostiole abnormalities, the guiding catheter is difficult to be coaxial and in place, in which case the extension catheter can play a role in maintaining coaxiality; 2) It is used to deliver special devices such as drug-eluting balloons and covered stents; 3) The extension catheter can enhance the support for antegrade and retrograde opening, and assist in the delivery of guidewires, microcatheters and balloons.
[0004] The transition section of existing guided extension catheter technology typically uses a metal ring (collar piece) connected (usually welded or riveted) to the end of the guide shaft. The metal ring is then inlaid and connected to the plastic layer of the guide tube to ensure tensile strength. The metal ring usually extends from the end of the plastic layer of the guide tube to the guide shaft and is cut in the transition area to form an arc-shaped or stepped metal skirt. This metal skirt is also the entrance to the inner lumen of the guide tube. The transition is completed through the arc or stepped shape of the metal skirt. Its advantages are that the metal structure provides good support for the inner lumen entrance and is not easy to collapse, with good mechanical transmission and high tensile strength. The disadvantages are that the transition section is too rigid, with poor bending performance and poor mechanical transition. There is a large stress concentration at the junction of the metal ring end and the guide tube, which can cause the tube body to bend at the junction and lose the inner lumen. In actual use, due to the poor bending performance, the guided extension catheter cannot reach the designated position to play its role, or it may cause damage to the patient's blood vessels due to excessive resistance during the advancement. Furthermore, the metal ring covering the outer layer of the catheter and the push rod welded to the metal ring mean that the guide tube lumen, metal ring, and push rod are located on three different horizontal planes. This reduces the coaxiality of the guiding and lengthening catheter, making it prone to folding when passing through tortuous blood vessels. Additionally, the welding method between the push rod and the metal ring increases the risk of breakage at the weld point, potentially leading to medical accidents during surgery. Utility Model Content
[0005] To overcome the aforementioned deficiencies of the prior art, this utility model provides a guiding extension catheter with a safer and more flexible structural design.
[0006] To achieve the above-mentioned objectives, this invention provides a guiding extension catheter, comprising an extension tube, a push rod, and a push handle; the extension tube includes an inner layer, a reinforcing layer, and an outer layer, the reinforcing layer being located between the inner and outer layers, the reinforcing layer being a stainless steel braided mesh with a braiding density of PPI ≥ 150; the reinforcing layer has a first imaging ring and a second imaging ring spaced apart, wherein the first imaging ring is located at the distal end of the catheter, and the second imaging ring is located at the proximal end of the extension tube; the push rod is integrally formed with the second imaging ring, and the push rod extends along the extension tube to the push handle; the outer layer of the extension tube and the push rod are coated with a hydrophilic coating.
[0007] In some embodiments, the push rod is a semi-circular hollow tube made of nickel-titanium alloy.
[0008] In some embodiments, the reinforcing layer is woven from circular knitting yarns with a diameter of 0.015-0.1 mm.
[0009] In some implementations, the push rod has a thickness of 0.2-1 mm and a width of 0.1-0.5 mm.
[0010] In some embodiments, a first marking ring is provided at a distance of 50 mm from the push handle on the push rod, and a second marking ring is provided at a distance of 100 mm from the distal end of the first marking ring. The first and second marking rings are made of platinum.
[0011] In some implementations, the push handle is made of polycarbonate.
[0012] In some embodiments, the outer diameter of the developing ring is 1.65 mm, the wall thickness is 0.1-0.2 mm, and the length is 1-3 mm.
[0013] In some implementations, the inner layer of the extension tube is made of highly lubricating PTFE material, and the outer layer is made of Pebax polymer material.
[0014] Compared with the prior art, the beneficial effects of this utility model are:
[0015] By integrating the push rod with the second imaging ring into a single unit, the problem of push rod breakage during use, which is often caused by welding in existing technologies, is solved. Furthermore, the push rod's semi-circular shape allows for a larger inner lumen compared to existing guide extension catheter designs, enabling better compatibility with more instruments, simplifying surgical procedures, and improving surgical efficiency. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the guiding and extension catheter structure of this application.
[0018] Figure 2 This is a schematic diagram of the push rod structure in this application.
[0019] Figure 3 This is a schematic diagram of the extension tube structure of this application.
[0020] Figure 4 This is a comparison diagram of the inner lumen size of the extension tube in this application and existing designs.
[0021] Icons: 1-First developing ring; 2-Extension tube; 3-Second developing ring; 4-Push rod; 5-Push handle;
[0022] 211-Hydrophilic coating; 212-Outer layer; 213-Reinforcing layer; 214-Inner layer. Detailed Implementation
[0023] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0024] 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 application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0025] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.
[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0027] In the description of the embodiments of this application, the technical terms "middle", "lower", "inner", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.
[0028] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "connection" and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can also refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.
[0029] like Figure 1-4 As shown, the guiding extension catheter includes an extension tube, a push rod, and a push handle. The extension tube includes an inner layer (214), a reinforcing layer (213), and an outer layer (212). The outer layer (212) is made of a polymer, such as Pebax; the inner layer (214) is made of a polymer, such as PTFE; the reinforcing layer (213) is a stainless steel braided mesh, woven from round braided wires with a diameter of 0.015-0.1 mm and a braiding density of PPI ≥ 150. A hydrophilic coating is applied to the outer surface of the extension tube to reduce vascular resistance.
[0030] Two developing rings are spaced apart on the braided layer of the extension tube. The developing ring at the distal end of the extension tube (away from the operating end) is defined as the first developing ring and is made of platinum; the developing ring at the proximal end of the extension tube (closer to the operating end) is defined as the second developing ring and is made of nickel-titanium alloy. The first and second developing rings are fixed to the reinforcing layer by pressing. The outer diameter of the developing ring is 1.65 mm, the wall thickness is 0.1 mm, 0.15 mm, or 0.2 mm, and the length is 1 mm, 1.5 mm, 2 mm, 2.5 mm, or 3 mm.
[0031] The second imaging ring extends axially upwards with a push rod that is a semi-circular hollow tube, also made of nickel-titanium alloy. The push rod has a thickness of 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, and a width of 0.1mm, 0.2mm, 0.3mm, 0.4mm, or 0.5mm. The push rod and the second imaging ring are integrally molded. The proximal end of the push rod (closer to the operating end) is bonded to the push handle with UV adhesive under UV lamp curing conditions. The push handle can be made of polymer materials such as polycarbonate. To facilitate identification of the length of the catheter inserted into the blood vessel, a first marking ring is located 50mm from the push handle, and a second marking ring is located 100mm distal to the first marking ring. Both the first and second marking rings are made of platinum.
[0032] The push rod and the second developing ring are integrally molded, avoiding the welding method used in existing designs to connect the extension tube and the push rod. Figure 4 As shown, in conventional methods, the push rod is welded to the extension tube or connector, which inevitably occupies part of the tube opening space. However, in this application's solution (B), the push rod is integrally formed with the imaging ring and is arc-shaped, completely eliminating the need to occupy the tube opening space and allowing for the accommodation of larger medical devices. Furthermore, the push rod is integrally formed with the second imaging ring, eliminating the problem of welding breakage.
[0033] On the other hand, in the present application, the push rod and the second developing ring are integrally formed and are semi-circular. It can be assumed that the axis of the extension tube and the push rod are at the same level. However, with the collar connector of the existing design, since the collar connector, the extension tube and the push rod need to be connected to each other, the axis cannot be kept at the same level, which is not conducive to the transmission of force.
[0034] To maintain the lubrication of the guide extension tube, both the extension tube and the push tube are coated with a hydrophilic coating on their outer surfaces.
[0035] Stent passability test
[0036] Experimental materials:
[0037] 1. 3D silicone blood vessels: Purchased from Ningbo Chuangdao 3D Medical Technology Co., Ltd. The model was made using 3D printing technology.
[0038] 2. Guide extension catheter with 4.0mm stent: Prepared according to the structure and method of this application, the guide extension catheter has a length of 1400mm, of which the length of the extension tube is 250mm; the length of the push rod is 1150mm; the outer layer of the extension tube is Pebax, the reinforcing layer is a 304 stainless steel braided layer with a braiding density of 150PPI, and the inner layer is high-lubricity PTFE. The three layers are fused together by heating at 200℃, and then the outermost high-lubricity hydrophilic coating is prepared by dip coating and UV curing process. The push rod and the handle are bonded with medical adhesive.
[0039] 3. Comparison product: Guidezilla extension catheter (similar product on the market), model 6Fr, manufactured by Boston Scientific Corporation.
[0040] Experimental methods:
[0041] Using 3D silicone blood vessels to simulate human blood vessels, a vascular stent with a nominal diameter of 4.0 mm was placed and evaluated for smooth stent delivery during PCI (percutaneous coronary intervention) procedures and techniques.
[0042] Experimental results: The Guidezilla extension catheter (comparative product) experienced scraping and resistance when the 4.0mm stent was delivered to the proximal inlet of the extension tube; the engineering sample of this invention had a smooth and unobstructed delivery process of the 4.0mm stent throughout the entire process.
[0043] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A guiding and lengthening catheter, characterized in that, Includes an extension tube, a push rod, and a push handle; The extension tube includes an inner layer, a reinforcing layer, and an outer layer. The reinforcing layer is located between the inner layer and the outer layer. The reinforcing layer is a stainless steel woven mesh with a weaving density of PPI ≥ 150. The reinforcing layer has a first developing ring and a second developing ring distributed at intervals, wherein the first developing ring is located at the far end of the extension tube and the second developing ring is located at the near end of the extension tube. The first developing ring is made of platinum and the second developing ring is made of nickel-titanium alloy. The push rod is integrally formed with the second developing ring, and the push rod extends along the extension tube to the push handle; The outer layer of the extension tube and the push rod are coated with a hydrophilic coating.
2. The guiding extension catheter according to claim 1, characterized in that... The push rod is a semi-circular hollow tube made of nickel-titanium alloy.
3. The guiding extension catheter according to claim 1, characterized in that... The reinforcing layer is woven from circular braided yarns with a diameter of 0.015-0.1 mm.
4. The guiding extension catheter according to claim 1, characterized in that... The thickness of the push rod is 0.2-1mm, and the width is 0.1-0.5mm.
5. The guiding extension catheter according to claim 1, characterized in that... The push rod is provided with a first marking ring 50mm away from the push handle, and a second marking ring is provided 100mm away from the first marking ring. The first and second marking rings are made of platinum.
6. The guiding extension catheter according to claim 1, characterized in that... The push handle is made of polycarbonate.
7. The guiding extension catheter according to claim 1, characterized in that... The outer diameter of the developing ring is 1.65 mm, the wall thickness is 0.1-0.2 mm, and the length is 1-3 mm.
8. The guiding extension catheter according to claim 7, characterized in that... The inner layer of the extension tube is made of highly lubricating PTFE material, and the outer layer is made of Pebax polymer material.