Balloon microcatheter and method of making a balloon microcatheter

Abstract

The embodiment of the present application provides a balloon microcatheter and a preparation method thereof, and relates to the field of medical devices. The balloon microcatheter has a hydrophilic lubricating layer, and the hydrophilic lubricating layer is coated on the balloon shoulder of the balloon microcatheter. Since the balloon of the balloon microcatheter is only partially coated with the hydrophilic lubricating layer, that is, the shoulder of the balloon microcatheter has the hydrophilic lubricating layer, and the working section of the balloon does not have the hydrophilic lubricating layer, the balloon has both anchoring and lubricating properties, the balloon microcatheter can pass through the contrast catheter and the tortuous and narrow blood vessel without resistance, and at the same time, the working section of the balloon anchors the blood vessel wall and can buffer the recoil force generated by the infusion of embolic materials; at the same time, the partial coating form can take into account the ductility of the balloon and the hydrophilic lubricating layer, so as to avoid the cracking and falling of the hydrophilic lubricating layer when the balloon expands, or the pinhole rupture of the balloon in the expansion process due to the restraint of the hydrophilic lubricating layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the domestic priority of the invention patent with the application date of December 2, 2022, the invention name of which is "Balloon microcatheter and balloon microcatheter preparation method" and the application number is 202211539705.1. Technical Field

[0003] The present invention relates to the field of medical devices, and in particular to a balloon microcatheter and a method for preparing the balloon microcatheter. Background Art

[0004] Balloon Occluded TACE (B-TACE) has been widely used in clinical practice since its introduction in Japan in 2011. Balloon microcatheter, the main interventional consumable of B-TACE, is a microcatheter equipped with a compliant balloon. While infusing embolic material, the balloon expands, changing hemodynamics and directing the embolic material toward the tumor-feeding artery, thereby effectively increasing the deposition density of the embolic material. At the same time, the expanded balloon adheres to the blood vessel wall to create a local occlusion environment, which can effectively prevent the embolic material from flowing back into normal tissue.

[0005] In the prior art, to ensure good device and vascular compatibility, balloon microcatheters are typically coated with a hydrophilic lubricating layer on the surface of the compliant balloon. However, both the balloon and the hydrophilic lubricating layer have a certain degree of ductility (and the ductility of the hydrophilic lubricating layer is less than that of the balloon). Therefore, in clinical practice, the hydrophilic lubricating layer often cracks and falls off during balloon inflation, or the balloon is constrained by the hydrophilic lubricating layer during inflation, resulting in pinhole ruptures, which can lead to surgical failure or corresponding complications. Summary of the Invention

[0006] The present invention provides a balloon microcatheter and a method for preparing the balloon microcatheter, which can avoid the phenomenon of cracking and shedding of a hydrophilic lubricating layer during balloon expansion, and avoid pinhole rupture caused by being constrained by the hydrophilic lubricating layer during balloon expansion.

[0007] The embodiments of the present invention can be implemented as follows:

[0008] An embodiment of the present invention provides a balloon microcatheter, comprising:

[0009] A balloon microcatheter and a hydrophilic lubricating layer are coated on the balloon shoulder of the balloon microcatheter.

[0010] Optionally, the balloon microcatheter includes a tube body and a balloon, the balloon is installed at one end of the tube body, the tube body includes an inner tube, an outer tube and a core wire, the outer tube is sleeved outside the inner tube, the core wire is wrapped around the outer wall of the outer tube, and the core wire abuts between the inner wall of the outer tube and the outer wall of the inner tube to limit the relative movement of the outer tube and the inner tube.

[0011] Optionally, part of the structure of the core wire is embedded in the outer tube.

[0012] Optionally, the core wire is connected to the proximal end of the balloon.

[0013] Optionally, the diameter of the balloon is 2 to 6 mm.

[0014] An embodiment of the present invention provides a method for preparing a balloon microcatheter, which comprises:

[0015] Provide balloon microcatheters;

[0016] A hydrophilic lubricating layer is coated on the balloon shoulder of the balloon microcatheter.

[0017] Optionally, the step of coating the shoulder of the balloon with a hydrophilic lubricating layer comprises:

[0018] inflating the balloon of the balloon microcatheter;

[0019] wrapping an isolation membrane around the working section of the balloon;

[0020] The balloon microcatheter with the isolation membrane is placed in a hydrophilic lubricating layer device to coat and solidify the hydrophilic lubricating layer.

[0021] Optionally, the isolation membrane is a PTFE film.

[0022] Optionally, the balloon microcatheter method comprises:

[0023] manufacturing the tube body;

[0024] The balloon is installed at one end of the tube.

[0025] The steps of manufacturing the tube body include:

[0026] Winding a core wire around the outer wall of the inner tube;

[0027] The outer tube is sheathed over the inner tube, wherein the core wire is located between the outer wall of the inner tube and the inner wall of the outer tube;

[0028] A heat shrink tube is sleeved on the outer side of the outer tube and rheoforming is performed so that part of the core wire is embedded in the outer tube and the core wire abuts against the outer wall of the inner tube.

[0029] Optionally, before the step of winding the core wire around the outer wall of the inner tube, the method for preparing the balloon microcatheter further comprises:

[0030] A core shaft is arranged in the inner cavity of the inner tube.

[0031] Optionally, the core wire is made of stainless steel, nickel-titanium alloy, or high-density linear polyethylene.

[0032] The beneficial effects of the balloon microcatheter and the method for preparing the balloon microcatheter according to the embodiments of the present invention include, for example:

[0033] Embodiments of the present invention provide a balloon microcatheter comprising a balloon microcatheter and a hydrophilic lubricating layer, the hydrophilic lubricating layer being coated on the shoulder portion of the balloon microcatheter. Because the hydrophilic lubricating layer is only partially coated on the balloon of the balloon microcatheter, cracking and shedding of the hydrophilic lubricating layer, which often occurs during balloon inflation, and pinhole rupture caused by the hydrophilic lubricating layer during balloon inflation can be avoided.

[0034] An embodiment of the present invention provides a method for preparing a balloon microcatheter, comprising: providing a balloon microcatheter; and coating a hydrophilic lubricating layer on the shoulder of the balloon microcatheter. Because the balloon of the balloon microcatheter is only partially coated with the hydrophilic lubricating layer, that is, the shoulder of the balloon microcatheter has the hydrophilic lubricating layer, while the working section of the balloon does not, the balloon has both anchoring and lubricating properties. The balloon microcatheter can pass through angiographic catheters and tortuous and narrow blood vessels without resistance. At the same time, the working section of the balloon anchors the blood vessel wall and can buffer the recoil force generated by the infusion of embolic materials. Due to the unique balloon structure, the wall thickness of the working section of the balloon is thinner at the intersection of the shoulder. Therefore, during the balloon inflation process, the working section of the balloon deforms before the shoulder, being elongated and increasing in diameter by 2-3 times, while the shoulder deformation is only 1.2-1.5 times. Therefore, the local coating form can take into account the ductility of the balloon and the hydrophilic lubricating layer, avoiding the hydrophilic lubricating layer from cracking and falling off during balloon expansion, or pinhole rupture caused by the hydrophilic lubricating layer during balloon expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic diagram of a balloon inflated into an "apple shape" in the prior art;

[0037] Figure 2 It is a schematic diagram of balloon folding in the prior art;

[0038] Figure 3 A schematic diagram of a balloon microcatheter provided in an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of a core wire wound around an inner tube provided in an embodiment of the present invention;

[0040] Figure 5 A cross-sectional view of a tube body provided in an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of an isolation membrane provided in an embodiment of the present invention wrapped around a working section of a balloon;

[0042] Figure 7 The results of the comparative experiments provided in the embodiments of the present invention are shown in FIG.

[0043] Figure 8 Schematic diagram of a balloon provided in an embodiment of the present invention.

[0044] Icon: 10-balloon microcatheter; 100-catheter seat; 200-tube body; 210-inner tube; 220-core wire; 230-outer tube; 201-spiral channel; 300-balloon; 310-shoulder; 320-working section; 20-isolation membrane. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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 herein can be arranged and designed in various different configurations.

[0046] 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 as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0047] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0048] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0049] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0050] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0051] Transcatheter arterial chemoembolization (TACE) is a common interventional therapy for unresectable hepatocellular carcinoma (HCC). It involves infusing a chemical embolic material (such as iodized oil, microspheres, or medical tissue glue) into the tumor's blood supply artery via a microcatheter, blocking it and causing tumor cells to undergo apoptosis and necrosis due to lack of nutrients. However, during the infusion of the embolic material, some of it inevitably refluxes into the normal liver parenchyma, causing accidental embolism and irreversible tissue damage.

[0052] Balloon Occluded TACE (B-TACE) has been widely used in clinical practice since its introduction in Japan in 2011. The balloon microcatheter is the main interventional consumable for B-TACE. It is a microcatheter equipped with a compliant balloon. While infusing the embolic material, the balloon expands, which changes the hemodynamics and causes the embolic material to flow directionaly toward the tumor-feeding artery, thereby effectively increasing the deposition density of the embolic material. At the same time, the expanded balloon adheres to the blood vessel wall to create a local occlusion environment, which can effectively prevent the embolic material from flowing back into normal tissue.

[0053] In the prior art, to ensure good device and vascular compatibility, balloon microcatheters are typically coated with a hydrophilic lubricating layer on the surface of the compliant balloon. However, both the balloon and the hydrophilic lubricating layer have a certain degree of ductility (and the ductility of the hydrophilic lubricating layer is less than that of the balloon). Therefore, in clinical practice, the hydrophilic lubricating layer often cracks and falls off during balloon inflation, or the balloon is constrained by the hydrophilic lubricating layer during inflation, resulting in pinhole ruptures, which can lead to surgical failure or corresponding complications.

[0054] Specifically, due to the unique balloon structure, the wall thickness of the working section of the balloon is thinner than that of the shoulder. Therefore, during the balloon expansion process, the working section of the balloon deforms before the shoulder. Usually, the length or diameter of the working section is stretched or expanded to 2-3 times, while the deformation of the shoulder is only 1.2-1.5 times.

[0055] Compared to the ductility of the balloon, the hydrophilic lubricating layer has less ductility, so the hydrophilic lubricating layer is often incompatible with balloon expansion, resulting in cracking and shedding of the hydrophilic lubricating layer or pinhole rupture caused by balloon expansion being constrained. Furthermore, existing balloon microcatheters use laser welding to connect coaxial catheters, which is difficult to operate and damages the integrity of the catheter surface. Furthermore, the discrete welding points make the mechanical transmission of the catheter uneven, with multiple mechanical inflection points, which can easily hinder push and even cause problems such as kinking and deformation. Alternatively, the only connection points between the inner and outer tubes of the balloon microcatheter are the catheter seat and the balloon, where the proximal and distal ends of the inner and outer tubes are connected to the catheter seat and the balloon, respectively. However, when the balloon microcatheter is pushed, relative displacement between the inner and outer tubes is likely to occur, leading to kinking and deformation.

[0056] In clinical practice, after puncturing the femoral or radial artery, the balloon microcatheter is navigated to the target lesion area with the support of a microguidewire, and the embolic material is delivered through the infusion lumen. At the same time, in order to prevent the embolic material from flowing into the normal liver parenchyma and causing accidental embolism, the balloon needs to be inflated while the embolic material is being infused to make it fit the blood vessel wall. Since the balloon is a compliant balloon, its length and diameter will change during the balloon filling process.

[0057] The soft distal end is stretched under the action of the tension in the balloon 300. After the embolic material is infused, the balloon 300 is deflated under the action of negative pressure. At this time, the tension in the balloon 300 is released and it is subjected to the tensile force of the negative pressure. That is, during the expansion of the balloon, the inner tube is pulled under the action of the tensile force. During the retraction of the balloon 300, the inner tube is pulled back, resulting in a difference in length from the original state, thereby causing the balloon 300 to fold. Figure 2 As shown, from top to bottom, the three states of the balloon 300 are the original state, the expanded state and the deflated state.

[0058] However, the rigid distal end does not stretch under the tension in the balloon 300, and the balloon 300 will be expanded into an "apple shape" (e.g. Figure 1 As shown), at this time, the expansion of the shoulder of the balloon 300 is restricted, resulting in a reduction in its rated diameter; at the same time, after the embolic material is infused, the balloon 300 is deflated under the action of negative pressure, and the balloon 300 retracts in an irregular shape, resulting in abnormal folding of the balloon 300.

[0059] In view of this, please refer to Figure 3-Figure 8The balloon microcatheter 10 and the method for preparing the balloon microcatheter provided in the embodiments of the present invention can solve this problem, which will be described in detail below.

[0060] Please refer to Figure 3-Figure 6 An embodiment of the present invention provides a balloon microcatheter 10, comprising a balloon microcatheter and a hydrophilic lubricating layer, the hydrophilic lubricating layer being coated on a shoulder portion 310 of a balloon 300 of the balloon microcatheter. Because the hydrophilic lubricating layer is only partially coated on a portion of the balloon 300 of the balloon microcatheter, cracking and shedding of the hydrophilic lubricating layer, which often occurs during balloon 300 inflation, and pinhole rupture caused by the hydrophilic lubricating layer during balloon 300 inflation can be avoided.

[0061] Specifically, the shoulder 310 of the balloon microcatheter has a hydrophilic lubricating layer, while the working section 320 of the balloon 300 does not have a hydrophilic lubricating layer, so that the balloon 300 has both anchoring and lubricating properties. The balloon microcatheter 10 can pass through the angiography catheter and tortuous and narrow blood vessels without resistance. At the same time, the working section 320 of the balloon 300 anchors the blood vessel wall and can buffer the recoil generated by the infusion of embolic materials. Due to the unique structure of the balloon 300, the wall thickness of the working section 320 of the balloon 300 is thinner at the intersection of the shoulder 310. Therefore, during the expansion process of the balloon 300, the working section 320 of the balloon 300 deforms before the shoulder 310. The working section 320 is elongated and its diameter increases by 2-3 times, while the deformation of the shoulder 310 is only 1.2-1.5 times.

[0062] The hydrophilic coating is omitted in the area of ​​balloon 300 where the balloon is most inflated, namely, the working section 320 of balloon 300. This helps ensure that the working section 320 of balloon 300 is not constrained by the ductility of the hydrophilic lubricating layer during the expansion process, which could lead to pinhole rupture. Meanwhile, the hydrophilic coating is applied to the area of ​​balloon 300 where the balloon is least inflated, namely, the shoulder 310 of balloon 300, which helps prevent the hydrophilic lubricating layer on the shoulder 310 from cracking or falling off. Therefore, the partial coating method can balance the ductility of both the balloon 300 and the hydrophilic lubricating layer, preventing the hydrophilic lubricating layer from cracking or falling off during the expansion of the balloon 300, or preventing the hydrophilic lubricating layer from constraining the balloon 300 during the expansion process, which could lead to pinhole rupture.

[0063] In this embodiment, the balloon microcatheter includes a tube body 200 and a balloon 300. The balloon 300 is installed at one end of the tube body 200. The tube body 200 includes an inner tube 210, an outer tube 230 and a core wire 220. The outer tube 230 is sleeved on the outer side of the inner tube 210. The core wire 220 is wrapped around the outer wall of the outer tube 230. The core wire 220 abuts between the inner wall of the outer tube 230 and the outer wall of the inner tube 210 to limit the relative movement of the outer tube 230 and the inner tube 210. In this way, the balloon microcatheter 10 is smoother during the pushing process.

[0064] Among them, part of the structure of the core wire 220 is embedded in the outer tube 230, the core wire 220 is connected to the proximal end of the balloon 300, and the diameter of the balloon 300 is 2 to 6 mm. The balloon 300 is specifically a compliant balloon 300. The diameter of the balloon 300 can be 2 to 6 mm. For example, the diameter of the balloon 300 can be 2 mm, 3 mm, 4 mm, 5 mm or 6 mm. The diameter of the balloon 300 is the rated diameter.

[0065] An embodiment of the present invention provides a method for preparing a balloon microcatheter, which can be used to prepare the balloon microcatheter 10 mentioned above. The method for preparing the balloon microcatheter includes:

[0066] S1. Provide a balloon microcatheter.

[0067] Specifically, the balloon microcatheter can directly adopt the balloon microcatheter in the prior art.

[0068] Of course, in this embodiment, the balloon microcatheter method includes:

[0069] S110. Make the pipe body 200.

[0070] The steps of manufacturing the tube body 200 include:

[0071] S111 , winding the core wire 220 around the outer wall of the inner tube 210 .

[0072] It should be noted that, in order to facilitate the winding of the core wire 220 around the outer wall of the inner tube 210, the method for preparing the balloon microcatheter 10 further includes, before the step of winding the core wire 220 around the outer wall of the inner tube 210, inserting a core shaft into the inner lumen of the inner tube 210. This allows the inner tube 210 to be unfolded and facilitates the winding of the core wire 220.

[0073] S112 , sleeve the outer tube 230 onto the inner tube 210 , wherein the core wire 220 is located between the outer wall of the inner tube 210 and the inner wall of the outer tube 230 .

[0074] S113 , a heat shrink tube is placed on the outside of the outer tube 230 and rheoforming is performed so that part of the core wire 220 is embedded in the outer tube 230 and the core wire 220 abuts against the outer wall of the inner tube 210 . At this point, the tube body 200 is completed.

[0075] S120 , installing the balloon 300 at one end of the tube 200 .

[0076] Specifically, the catheter seat 100 and the balloon 300 are respectively installed at both ends of the tube body 200 to manufacture the balloon microcatheter 10 , wherein the catheter seat 100 is installed at the proximal end of the tube body 200 and the balloon 300 is located at the distal end of the tube body 200 .

[0077] It is easy to understand that the tube body 200 has a spiral core wire 220, wherein the core wire 220 extends from the proximal end of the inner tube 210 to the proximal end of the balloon 300 or inside the balloon 300, and the inner tube 210 and the outer tube 230 are coaxially connected through the core wire 220. The core wire 220 can limit the relative displacement between the inner tube 210 and the outer tube 230, and a spiral channel 201 for conveying contrast agent is formed between the inner tube 210 and the outer tube 230, that is, the addition of the core wire 220 creates a predetermined contrast agent filling route for the flow of contrast agent.

[0078] At the same time, the addition of the core wire 220 allows for controllable rigidity and flexibility at the distal end of the tube body 200, preventing the release of tension within the balloon 300 and the resulting negative pressure pull. This occurs when the balloon 300 expands, pulling on the inner tube 210. During the deflation process, the inner tube 210 is pulled back, resulting in a difference in length from its original state. Therefore, the addition of the core wire 220 helps prevent the balloon 300 from folding during expansion and deflation.

[0079] In addition, in this embodiment, the core wire 220 is not welded to the inner tube 210 by laser welding. The pitch stability of the core wire 220 is better, and the integrity of the surface of the tube body 200 is not damaged. The mechanical transmission of the tube body 200 is more uniform, avoiding problems such as push being easily blocked or even twisting and deformation.

[0080] It should be noted here that the pitch of the core wire 220 decreases successively along the length direction of the inner tube 210, and the pitch of the core wire 220 close to one end of the balloon 300 is the smallest. At the same time, the material of the core wire 220 is stainless steel, nickel-titanium alloy, or high-density linear polyethylene. In this embodiment, the material of the core wire 220 can be stainless steel. At the same time, in this embodiment, the core wire 220 is connected to the proximal end of the balloon 300.

[0081] Thus, the core wire 220 at one end close to the catheter seat 100 has a larger pitch, which can fill and retract the contrast agent in a shorter time, while the core wire 220 at one end away from the catheter seat 100 has a relatively smaller pitch, which can help prevent the balloon 300 from rupturing due to rapid filling.

[0082] At the same time, the core wire 220 extending to the proximal end of the balloon 300 can connect and fix the proximal end of the balloon 300 to the inner tube 210 on one side of the catheter seat 100, so as to prevent the balloon 300 from being relatively displaced toward the proximal end of the tube body 200 when inflated, that is, to ensure the rigidity and flexibility of the distal end of the tube body 200, and to ensure unidirectional displacement of the inner tube 210 during the process of expanding and retracting the balloon 300, thereby preventing the balloon 300 from stacking and folding.

[0083] S2. Coating a hydrophilic lubricating layer on the shoulder 310 of the balloon 300 of the balloon microcatheter.

[0084] Specifically, the step of coating the hydrophilic lubricating layer on the shoulder 310 of the balloon 300 comprises:

[0085] S201, inflate the balloon 300 of the balloon microcatheter.

[0086] Specifically, clean air is filled into the balloon 300, so that the diameter of the balloon 300 of the balloon microcatheter is 2mm.

[0087] S202, wrap the isolation film 20 on the working section 320 of the balloon 300.

[0088] It should be noted that in the present embodiment, preferably, the isolation film 20 is a PTFE film, which completely covers the working section 320 of the balloon 300, and then the coating of the hydrophilic lubricating layer is performed.

[0089] S203, place the balloon microcatheter with the isolation film 20 in the hydrophilic lubricating layer device to perform the coating and curing of the hydrophilic lubricating layer.

[0090] And the balloon microcatheter is subjected to the processes of standing, light irradiation and pulling back, preferably, the standing time is 15-30s, the pulling back speed is 8-15mm / s, and the light irradiation time is 160-250s, so that the outer wall of the tube body 200 and the shoulder 310 of the balloon 300 of the balloon microcatheter have the hydrophilic lubricating layer, while the working section 320 of the balloon 300 does not have the hydrophilic lubricating layer, that is, only part of the surface of the balloon 300 is coated with the hydrophilic lubricating layer, at this time, the friction of the working section 320 of the balloon 300 is greater than that of the shoulder 310 of the balloon 300, and since the friction of the working section 320 of the balloon 300 is greater, the balloon 300 has an anchoring function, that is, the working section 320 of the balloon 300 anchors the blood vessel wall, and can buffer the recoil force generated by the infusion of embolic materials.

[0091] It should be noted that in the present embodiment, the material of the hydrophilic lubricating layer is polyvinylpyrrolidone (PVP) and polyacrylamide (PAM).

[0092] Since the balloon 300 of the balloon microcatheter is only partially coated with the hydrophilic lubricating layer, that is, the shoulder 310 of the balloon microcatheter has the hydrophilic lubricating layer, while the working section 320 of the balloon 300 does not have the hydrophilic lubricating layer, the balloon 300 has both anchoring and lubricating properties, and the balloon microcatheter 10 can pass through the contrast catheter and the tortuous and narrow blood vessel without resistance, while the working section 320 of the balloon 300 anchors the blood vessel wall, and can buffer the recoil force generated by the infusion of embolic materials.

[0093] In order to better illustrate the effect of the balloon microcatheter 10, a comparative experiment of the rated diameter of the balloon 300 is also performed, please refer to Figure 7 , and the specific results are as follows:

[0094] Wherein, embodiment / comparative example explanation:

[0095] The embodiment is a schematic diagram of the hydrophilic lubricating layer coating of the balloon 300. Figure 6 As shown, the entire working section 320 of the balloon 300 is covered with the isolation membrane 20 , so that the hydrophilic lubricating layer covers all areas of the shoulder 310 of the balloon 300 , and the working section 320 of the balloon 300 has no hydrophilic lubricating layer.

[0096] Among them, the difference between comparative example 1 / 2 and the embodiment is only the coating length of the shoulder 310 of the balloon 300. The relative coating lengths of the shoulder 310 are -1mm and -2mm respectively, that is, the length is reduced by 1mm and 2mm relative to the coating length of the shoulder 310 of the embodiment.

[0097] The only difference between comparative examples 3 / 4 and the embodiment is the coating length of the working section 320 of the balloon 300. In this case, the working section 320 of the balloon 300 has a hydrophilic lubricating layer, and the relative coating lengths are 1 mm and 2 mm, respectively.

[0098] Analysis shows that the hydrophilic lubricating layer of the embodiment covers all areas of the shoulder 310 of the balloon 300, and the working section 320 of the balloon 300 has no hydrophilic lubricating layer. At this time, the rated diameter of the balloon 300 is 6 mm, and its friction coefficient is 0.04.

[0099] As the length of the hydrophilic lubricating layer of the shoulder 310 is shortened, its friction coefficient gradually increases from 0.04 to 0.055. At this time, the rated diameter of the balloon 300 does not change.

[0100] As the coating length of the hydrophilic lubricating layer of the working section 320 of the balloon 300 gradually increases, the rated diameter of the balloon 300 decreases from 6 mm to 4.5 mm, and its friction coefficient gradually decreases from 0.04 to 0.03. Therefore, in summary, the embodiment of the patent of the present invention achieves good comprehensive performance.

[0101] In addition, it should be noted that the test methods for the rated diameter of the balloon 300 include:

[0102] Step A1: Connect a negative pressure syringe filled with contrast agent to the filling cavity of the balloon 300, pull the push rod of the negative pressure syringe and lock it to expel the gas in the filling cavity of the balloon 300;

[0103] Step A2: Using a micro-guidewire to support the lumen of the inner tube 210 of the balloon microcatheter 10, the balloon 300 is completely submerged in a 37°C water bath;

[0104] Step A3: Connect the syringe filled with contrast agent to the filling port of the balloon 300, fill the balloon 300 according to the volume gradient, and equilibrate in a water bath for 2 minutes. Record the maximum diameter of the balloon 300 without damage, which is the rated diameter of the balloon 300.

[0105] The friction coefficient test method of the balloon microcatheter 10 includes:

[0106] Step B1: Place the balloon microcatheter 10 and the angiographic catheter in a 37° C. water bath to activate the hydrophilic lubricating layer on the surface of the tube body 200;

[0107] Step B2: With the support of the micro-guidewire, the balloon microcatheter 10 is passed through the angiography catheter, and the end of the balloon microcatheter 10 is exposed 300 mm;

[0108] Step B3: Fixing one end of the balloon microcatheter 10 on the fixture of the friction force tester;

[0109] Step B4: Activate the test program to start the test and read the friction coefficient value from the instrument.

[0110] In addition, an embodiment of the present invention further provides a balloon microcatheter 10 , which is manufactured using the above-mentioned method for manufacturing the balloon microcatheter 10 and has all the functions of the above-mentioned method for manufacturing the balloon microcatheter 10 .

[0111] At the same time, and refer to Figure 8 The balloon microcatheter 10 provided in this embodiment has three balloon 300 states from top to bottom, namely, the original state, the expanded state, and the retracted state. In the retracted state, the balloon 300 will not be folded or stacked.

[0112] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A balloon microcatheter, characterized in that: include: The balloon microcatheter comprises a tube body (200) and a compliant balloon (300), wherein the compliant balloon (300) is mounted on one end of the tube body (200), and the compliant balloon (300) comprises a shoulder (310) and a working section (320), wherein the shoulder (310) is coated with a hydrophilic lubricating layer, and the hydrophilic lubricating layer covers all areas of the shoulder (310); The tube body (200) comprises an inner tube (210), an outer tube (230), and a core wire (220); the outer tube (230) is sleeved outside the inner tube (210); a portion of the core wire (220) is embedded in the outer tube (230); the core wire (220) is wound around the outer wall of the inner tube (210); and the core wire (220) abuts between the inner wall of the outer tube (230) and the outer wall of the inner tube (210) to limit relative movement between the outer tube (230) and the inner tube (210); During the expansion of the compliant balloon (300), the working section (320) is elongated and its diameter increases by 2-3 times, and the deformation of the shoulder (310) is 1.2-1.5 times; the expansion degree of the working section (320) is greater than the expansion degree of the shoulder (310); The ductility of the hydrophilic lubricating layer is less than the ductility of the balloon (300); The working section (320) of the compliant balloon (300) is not coated with the hydrophilic lubricating layer.

2. The balloon microcatheter according to claim 1, characterized in that: The core wire (220) is connected to the proximal end of the compliant balloon (300).

3. The balloon microcatheter according to claim 1, characterized in that: The diameter of the compliant balloon (300) is 2-6 mm.

4. A method for preparing a balloon microcatheter, characterized in that: include: Provide balloon microcatheters; A hydrophilic lubricating layer is coated on the shoulder (310) of the balloon (300) of the balloon microcatheter, wherein the hydrophilic lubricating layer covers all areas of the shoulder (310); The step of coating the shoulder (310) of the balloon (300) of the balloon microcatheter with a hydrophilic lubricating layer comprises: A balloon (300) is filled in the balloon (300) catheter; Wrapping an isolation membrane (20) in the working section (320) of the balloon (300); Placing the balloon (300) catheter having the isolation membrane (20) in a hydrophilic lubricating layer device to coat and solidify the hydrophilic lubricating layer; The balloon microcatheter method comprises: Make tube body (200); The balloon (300) is installed at one end of the tube (200); Wherein, the steps of manufacturing the tube body (200) include: Winding a core wire (220) around the outer wall of the inner tube (210); The outer tube (230) is sleeved on the outer side of the inner tube (210), wherein the core wire (220) is located between the outer wall of the inner tube (210) and the inner wall of the outer tube (230); A heat shrink tube is sheathed on the outer side of the outer tube (230) and rheoformed to allow a portion of the core wire (220) to be embedded in the outer tube (230), and the core wire (220) to abut against the outer wall of the inner tube (210); During the expansion of the balloon (300), the working section (320) is elongated and its diameter increases by 2-3 times, and the deformation of the shoulder (310) is 1.2-1.5 times; the expansion degree of the working section (320) is greater than the expansion degree of the shoulder (310); The ductility of the hydrophilic lubricating layer is less than the ductility of the balloon (300); The working section (320) of the balloon (300) is not coated with the hydrophilic lubricating layer; The balloon (300) is a compliant balloon.

5. The method for preparing a balloon microcatheter according to claim 4, characterized in that: The isolation membrane (20) is a PTFE film.

6. The method for preparing a balloon microcatheter according to claim 4, characterized in that: Before the step of winding the core wire (220) around the outer wall of the inner tube (210), the method for preparing the balloon microcatheter further comprises: A core shaft is arranged in the inner cavity of the inner tube (210).

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