Balloon dilatation catheter capable of conveying intracavitary treatment instruments

Abstract

The invention relates to a balloon dilatation catheter capable of conveying intracavity treatment instruments, and relates to the technical field of medical equipment. Comprising a Luer taper, an inner tube, an outer tube, a balloon and a head end, one end of the inner tube is connected with the Luer taper, the other end of the inner tube is connected with the head end, one end of the outer tube is connected with the Luer taper, the other end of the outer tube is connected with the balloon, and the inner tube is sleeved with the outer tube and the balloon. The balloon is of a three-layer structure and sequentially comprises a sealing layer, a structural layer and a blood vessel contact layer from inside to outside. The device can be used for conveying and releasing thrombectomy stents and intracranial stents; the operation complexity of doctors is simplified, the process is simplified, the operation time is shortened, the safety is improved, and timely treatment of diseases is facilitated.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a balloon dilation catheter capable of delivering intracavitary therapeutic instruments. Background Technology

[0002] Balloon catheters are widely used in the treatment of intracranial vascular stenosis or acute thrombectomy, primarily to dilate blood vessels or block proximal blood flow. The current standard procedure involves first inserting a balloon catheter, then removing it, and finally using a microcatheter. This process is cumbersome, prolongs the procedure, is time-consuming and labor-intensive, and is not conducive to timely treatment.

[0003] Therefore, how to provide a balloon dilation catheter that can deliver endovascular therapeutic devices has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a balloon dilation catheter that can deliver intracavitary therapeutic instruments. It can be used for the delivery and release of thrombectomy stents and intracranial stents. It simplifies the cumbersome operation of doctors, simplifies the process, reduces the operation time, improves safety, and is conducive to the timely treatment of diseases.

[0005] To achieve the above objectives, the present invention provides a balloon dilation catheter for delivering endovascular therapeutic devices, comprising: a Luer connector, an inner tube, an outer tube, a balloon, and a tip; one end of the inner tube is connected to the Luer connector, and the other end is connected to the tip; one end of the outer tube is connected to the Luer connector, and the other end is connected to the balloon, and both the outer tube and the balloon are fitted onto the inner tube; the balloon is configured with a three-layer structure, consisting of a sealing layer, a structural layer, and a blood vessel contact layer, from the inside out.

[0006] Furthermore, the outer surface of the balloon is provided with a nanoscale groove structure.

[0007] Furthermore, the Luer connector is provided with a conical inlet 1 and a conical inlet 2. The conical inlet 1 is connected to the inner tube, and the conical inlet 2 is connected to the channel between the outer tube and the inner tube.

[0008] Furthermore, the sealing layer is made of block polyetheramide.

[0009] Furthermore, the structural layer is made of a nanoscale blend of polyethylene terephthalate and nylon 12.

[0010] Furthermore, the material of the contact blood vessel layer is styrene block copolymer or TPU.

[0011] Furthermore, the inner tube is configured with a three-layer structure, with the outer layer made of polyether block amide, the middle layer made of polyurethane, and the inner layer made of polytetrafluoroethylene coating.

[0012] Furthermore, a highly visible platinum-iridium alloy marker band is set at each end of the balloon. The proximal platinum-iridium alloy marker band is connected to the inner tube, while the distal platinum-iridium alloy marker band has a small, controllable axial sliding gap with the guidewire.

[0013] Furthermore, the inner wall of the outer tube is provided with a spiral guide groove with a width of 0.1 mm and a depth of 0.05 mm.

[0014] Furthermore, the head end adopts a gradient hardness design, with a hardness of 72D at the proximal end and decreasing to 55D at the distal end, and the material is polyether block amide resin; and the head end has a bullet-shaped structure with a bevel angle of 15°.

[0015] The beneficial effects of this invention are as follows: This invention can be used for the delivery and release of thrombectomy stents and intracranial stents; it simplifies the cumbersome surgical procedures for doctors, streamlines the process, reduces surgical time, improves safety, and facilitates timely treatment of diseases. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the balloon of the present invention.

[0017] In the figure: 1. Luer connector; 2. Inner tube; 3. Outer tube; 4. Balloon; 5. Head end; 6. Conical inlet port one; 7. Conical inlet port two; 8. Sealing layer; 9. Structural layer; 10. Contact vessel layer. Detailed Implementation

[0018] To achieve the above objectives and effects, the technical means and structure adopted by the present invention will be described in detail with reference to the accompanying drawings, focusing on the features and functions of the preferred embodiments of the present invention.

[0019] like Figure 1 and Figure 2 As shown, the present invention provides a neurovascular balloon dilation catheter 4 for pushing intracranial thrombectomy stents, comprising: a Luer connector 1, an inner tube 2, an outer tube 3, a balloon 4, and a tip 5; one end of the inner tube 2 is connected to the Luer connector 1, and the other end is connected to the tip 5; one end of the outer tube 3 is connected to the Luer connector 1, and the other end is connected to the balloon 4, and both the outer tube 3 and the balloon 4 are fitted onto the inner tube 2; the balloon is configured with a three-layer structure, consisting of a sealing layer 8, a structural layer 9, and a vascular contact layer 10, from the inside out.

[0020] To further optimize the technical solution, the outer surface of the balloon 4 is provided with a nanoscale groove structure, which can greatly reduce the damage to the blood vessel wall during expansion.

[0021] To further optimize the technical solution, the Luer connector 1 is equipped with a conical inlet 6 and a conical inlet 7. The conical inlet 6 is connected to the inner tube 2, and the conical inlet 7 is connected to the channel between the outer tube 3 and the inner tube 2. The conical inlet 6 allows for the independent delivery of a stent or medication to the inner tube 2, enabling the release of the thrombectomy stent or medication to the intracranial lesion. The conical inlet 7 allows for the independent delivery of fluid to the channel between the outer tube 3 and the inner tube 2. The delivery and withdrawal of the fluid causes the balloon 4 to inflate and contract, thereby pushing and withdrawing the tip 5, thus realizing the function of the balloon 4 as a dilation catheter and microcatheter.

[0022] Considering that most balloons compromise between compliance, nominal pressure, and burst pressure, high-compliance balloons are prone to the dog-bone effect, excessively stretching normal blood vessels at both ends of the lesion; while low-compliance (semi-compliant or non-compliant) balloons are prone to vascular tearing if pressure is not properly controlled. Therefore, the sealing layer 8 of this invention is made of block polyetheramide, and the sealing layer 8 is made of a flexible material with good adhesion to the balloon 4, ensuring a reliable seal with the catheter lumen. The structural layer 9 is made of a nanoscale blend of polyethylene terephthalate (PET) and nylon 12. By controlling the mixing ratio and processing technology (such as biaxial stretching) of the two materials, the balloon 4 exhibits characteristics similar to a semi-compliant balloon before reaching the nominal pressure (e.g., 6-8 atm), facilitating initial shaping and passage through tortuous sections. Once the pressure exceeds the nominal pressure, the molecular chain network of PET rapidly dominates the mechanical behavior, causing the balloon 4 to enter a working plateau period. Within this pressure range (e.g., 8-12 atm), the change rate of the balloon 4 diameter with increasing pressure is extremely small (i.e., low compliance), thereby safely and powerfully focusing and dilating calcified plaques while effectively suppressing the dog bone effect. The vascular contact layer 10 is made of styrene block copolymer or TPU. The surface of this material can be molecularly smoothed, and antiproliferative drugs (such as paclitaxel) or anti-inflammatory drugs can be uniformly dispersed in its matrix to inhibit intimal hyperplasia after balloon 4 dilation and prevent restenosis (it can be used as a variant of drug-eluting balloon DCB). The design of the balloon 4 gives it a unique pressure-diameter curve, which ensures good permeability and initial shaping ability under certain pressure, while providing stable and controllable expansion force within the treatment pressure range, effectively opening calcified plaques, and minimizing the risk of canine bone effect and vascular tearing.

[0023] Furthermore, the overall shape of balloon 4 is slightly spindle-shaped, rather than the traditional cylindrical shape. That is, the diameter of the middle part of balloon 4 is slightly larger than that of the two ends (the difference is approximately 0.1mm-0.25mm). This design allows balloon 4 to make initial contact with the lesion at the middle, which is beneficial for focused rupture of the plaque at the center and guides the plaque to slightly shift towards both ends, rather than being forcibly cut off, thus reducing the risk of embolism. The tapered transition section of balloon 4 is designed to be long and gentle, reducing stress concentration on normal blood vessels.

[0024] Further optimization of the technical solution revealed that an overly flexible inner catheter 2 was difficult to advance to distal lesions, while a highly maneuverable inner catheter 2 often lacked flexibility and was prone to damaging the vessels along the path. Therefore, the inner catheter 2 was designed with a three-layer structure: the outer layer uses polyether block amide to improve flexibility and kink resistance; the middle layer uses polyurethane to enhance elastic recovery; and the inner layer uses a polytetrafluoroethylene coating to reduce frictional resistance when delivering stents or drugs. In vitro simulation experiments showed that the improved catheter's free taper (FTA) was reduced by 30% (from 0.8N to 0.56N), resulting in smoother advancement; kink resistance was also improved; in a 2mm radius bending test, the improved catheter did not exhibit kinking, while the original catheter had a kinking rate of 15%.

[0025] In addition, the inner tube 2 can also employ a multi-layered composite structure that gradually transitions from proximal to distal to achieve smooth force transmission and a gradient change in compliance: the proximal end is composed of stainless steel braided mesh or high-modulus polymer (such as Pebax 7233) segments, providing strong pushing force and bending resistance. The outer layer is coated with a hydrophilic coating to reduce friction with the guide tube. The intermediate transition section uses multi-segment polymer co-extrusion technology (such as the Pebax series), with its hardness gradually decreasing from proximal to distal. Spiral-wound stainless steel wires or flat wires are embedded in this section; this winding structure has a small spacing and thick wires at the proximal end, providing tensile strength and torque transmission. At the distal end, the spacing increases, the wires become thinner or flatter, gradually enhancing compliance. This composite multi-layered gradient inner tube 2 design perfectly balances pushing force, bending resistance, torque response, and distal compliance, enabling it to safely and smoothly pass through extremely tortuous anatomical structures such as the internal carotid artery siphon, directly reaching distal lesions such as the M2 segment of the middle cerebral artery. The ultra-lubricated inner tube design greatly facilitates the operation of the microguidewire and shortens the operation time.

[0026] To further optimize the technical solution, a highly visible platinum-iridium alloy marker strip is placed at each end of the balloon 4. The proximal platinum-iridium alloy marker strip is connected to the inner tube 2, while a small, controllable axial sliding gap (preferably 0.5-1.5 mm) is provided between the distal platinum-iridium alloy marker strip and the guidewire. When the balloon 4 inflates in a tortuous blood vessel, this sliding gap allows the catheter system to adaptively fine-tune, absorbing some of the displacement caused by vascular pulsation and blood flow impact, thereby making the positioning of the balloon 4 at the lesion site more stable and reducing the "watermelon seed effect." Through the ingenious design of the mechanical structure, the stability of the balloon 4 in a dynamic blood flow environment is improved, ensuring the accuracy of expansion.

[0027] To further optimize the technical solution, a spiral guide groove with a width of 0.1 mm and a depth of 0.05 mm is provided on the inner wall of the outer tube 3, which can reduce the resistance to liquid flow. Experimental verification shows that the inflation time of the balloon 4 is shortened from 3.2 seconds to 1.8 seconds, and the negative pressure requirement for aspiration is reduced by 25%.

[0028] The technical solution is further optimized by adopting a gradient hardness design for the head end 5, with a hardness of 72D at the proximal end and 55D at the distal end. The material is polyether block amide resin. Furthermore, the head end 5 adopts a bullet-shaped structure with a 15° bevel angle, which can increase the success rate from 85% to 98% and reduce the deformation rate of the head end 5 by 50%.

[0029] This invention can be used for the delivery and release of thrombectomy stents and intracranial stents; it simplifies the cumbersome surgical procedures for doctors, streamlines the process, reduces surgical time, improves safety, and facilitates timely treatment of diseases. Experimental verification shows that the improved catheter can significantly shorten surgical time (estimated to be reduced by 20-30%), reduce the risk of complications (such as vasospasm and perforation), and simultaneously enhance the ability to handle complex vascular lesions.

[0030] The process of using this invention: Taking the treatment of M1 segment stenosis of the middle cerebral artery as an example: After establishing a path with the guiding catheter and microguidewire, the catheter of this invention is delivered along the microguidewire. Thanks to its excellent compliance and tracking ability, the catheter smoothly traverses the tortuous path until the two marker bands on the balloon straddle both ends of the stenotic lesion. The pressure-time dual-control inflation device is connected, with a preset pressure of 8 atm and a maintenance time of 45 seconds. The inflation device handle is slowly and evenly pushed, and the pressure gauge is observed. The balloon gradually inflates, with its spindle-shaped midsection initially applying pressure to the narrowest point. Due to its focused, low-compliance characteristics, the balloon enters a plateau phase after reaching 7 atm, providing continuous and stable dilation of the calcified plaque, while the normal vessels at both ends experience gentle pressure. After maintaining dilation for 45 seconds, the balloon is slowly deflated. Angiography confirms satisfactory improvement in vessel diameter and the absence of complications such as dissection. The entire catheter is withdrawn into the guiding catheter, and the procedure is complete.

[0031] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A balloon dilation catheter for delivering endocavitary therapeutic instruments, characterized in that, include: The device comprises a Luer connector, an inner tube, an outer tube, a balloon, and a tip. One end of the inner tube is connected to the Luer connector, and the other end is connected to the tip. One end of the outer tube is connected to the Luer connector, and the other end is connected to the balloon. Both the outer tube and the balloon are fitted onto the inner tube. The balloon has a three-layer structure, consisting of a sealing layer, a structural layer, and a blood vessel contact layer, arranged sequentially from the inside out.

2. The balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The outer surface of the balloon is provided with a nanoscale groove structure.

3. The balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The Luer connector is provided with a conical inlet 1 and a conical inlet 2. The conical inlet 1 is connected to the inner tube, and the conical inlet 2 is connected to the channel between the outer tube and the inner tube.

4. The balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The sealing layer is made of block polyether amide.

5. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 4, characterized in that, The structural layer is made of a nanoscale blend of polyethylene terephthalate and nylon 12.

6. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 5, characterized in that, The material of the contact blood vessel layer is styrene block copolymer or TPU.

7. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The inner tube is configured with a three-layer structure: the outer layer is made of polyether block amide, the middle layer is made of polyurethane, and the inner layer is made of polytetrafluoroethylene coating.

8. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, A highly visible platinum-iridium alloy marker band is set at each end of the balloon. The proximal platinum-iridium alloy marker band is connected to the inner tube, while the distal platinum-iridium alloy marker band has a small, controllable axial sliding gap between it and the guidewire.

9. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The inner wall of the outer tube is provided with a spiral guide groove with a width of 0.1 mm and a depth of 0.05 mm.

10. A balloon dilation catheter for delivering endocavitary therapeutic devices as described in claim 1, characterized in that, The head end adopts a gradient hardness design, with a hardness of 72D at the proximal end and decreasing to 55D at the distal end. The material is polyether block amide resin. The head end is bullet-shaped with a 15° bevel angle.

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