Catheter for expanding severe stenosis renal artery opening

Abstract

The utility model provides a catheter used for expanding a severe stenosis renal artery opening, the catheter is an elastic catheter, two ends of the catheter are respectively an input port and an output port, the catheter comprises a straight section, a bending section and an attacking section which sequentially extend between the input port and the output port, and the straight section is provided with an opening. The end, away from the input port, of the straight section extends towards one side in the radial direction to form the bent section and the straight section, and the included angle between the axis of the attack section and the axis of the straight section is not larger than 90 degrees. According to the catheter for expanding the severe stenosis renal artery opening, based on the anatomical structure relation between the renal artery and the aorta abdominalis, the attack section located at the head end of the catheter and the telecentric end of the aorta abdominalis form a right angle or an acute angle, and the appearance and the elasticity modulus of the attack section are limited, so that tension and stress of the bent section can be smoothly transferred; and therefore, the needle can easily and smoothly pass through the narrow section of artery during rolling and impact.

Description

Technical Field

[0001] This utility model relates to the field of interventional angiography catheter technology, and in particular to a catheter for dilating the orifice of a severely stenotic renal artery. Background Technology

[0002] Regarding the application of catheters in interventional therapy, Chinese utility model patent CN213963379U discloses a dedicated left and right adrenal vein blood collection catheter via the femoral vein. It has multiple bends to conform to the anatomical characteristics of the left and right adrenal veins. With the bends having a certain angle, coupled with the catheter's good flexibility and high plasticity, doctors can easily adjust the angle of the bends by gently following the arc trajectory, based on the anatomical characteristics of the left and right adrenal veins and different doctors' operating habits.

[0003] However, existing technologies have the following drawbacks during implementation:

[0004] After a thin guidewire successfully passes through a narrowed or nearly occluded renal artery, the key is to successfully pass the catheter through the narrowed segment. However, in Takayasu arteritis, since most patients have subclavian artery involvement, the femoral artery puncture approach is often used. Traditional SIM1 catheters, RH catheters, and single-curve catheters are more suitable for radial artery approaches, are used for angiographic assessment, have a large arterial orifice angle, and have low resistance, but in clinical practice they cannot successfully enter the renal artery, leading to surgical failure. In addition, unlike renal artery stenosis caused by traditional atherosclerosis, which is mainly located in the middle segment of the renal artery, renal artery stenosis caused by Takayasu arteritis is mainly located at the renal artery orifice, and the lesion is longer. Moderate to severe renal artery orifice stenosis that is an indication for interventional surgery often makes it difficult to pass the guidewire and catheter. Even if the guidewire passes through successfully, the catheter often slips out of the artery due to large tension and torque, making it impossible to continue subsequent treatment.

[0005] Therefore, in order to solve the above problems, this utility model proposes a catheter for dilating severely narrowed renal artery openings that can pass through the narrow renal artery opening without slipping out. Utility Model Content

[0006] To address the problem that existing catheters used for dilating severely stenotic renal artery orifices are difficult to pass through and are prone to slipping out, this invention provides a novel catheter for dilating severely stenotic renal artery orifices.

[0007] According to one objective of this utility model, this utility model provides a catheter for dilating the orifice of a severely stenotic renal artery. The catheter is an elastic catheter with an input port and an output port at its two ends. The catheter includes a straight section, a curved section, and an attack section extending sequentially between the input port and the output port. The end of the straight section away from the input port extends radially to form the curved section and the straight section. The angle between the axis of the attack section and the axis of the straight section is no greater than 90 degrees. The outer diameter of the attack section gradually decreases as it approaches the output port. The elastic modulus of the curved section is less than that of the attack section.

[0008] Preferably, the inner wall thickness of the attack segment is equal in the circumferential direction at any point in the axial direction, and the inner wall thickness of the attack segment gradually decreases as it approaches the output port.

[0009] Preferably, the inner diameter of the attack segment gradually decreases as it approaches the output port, and the end of the attack segment furthest from the output port is the connection end. The difference between the inner diameter of the connection end and the inner diameter of the output port is much smaller than the difference between the outer diameter of the connection end and the outer diameter of the output port.

[0010] Preferably, the inner diameter of the attack segment is the same at any point along the axial direction.

[0011] Preferably, the conduit includes a flexible element and a rigid element, and the elastic modulus of the bending section and the attack section is controlled by adjusting the ratio of the flexible element and the rigid element.

[0012] Preferably, the flexible component is nylon and polyurethane, the rigid component is steel wire and polytetrafluoroethylene, the polyurethane content in the bending section is higher than the polyurethane content in the attacking section, and the polytetrafluoroethylene and steel wire content in the bending section is lower than the polytetrafluoroethylene and steel wire content in the attacking section.

[0013] Preferably, the angle between the axis of the attack segment and the axis of the straight segment is less than 90 degrees.

[0014] Preferably, the length of the attack segment is no more than 1 cm.

[0015] Preferably, the attack section is covered with a radiopaque coating, which is configured to block X-rays.

[0016] Preferably, the radial cross-sectional dimension of the straight section near the input port gradually increases towards the input port to form a connecting portion;

[0017] The outer radial side of the connector is provided with a raised thread that matches the thread cap of the syringe pump connecting tube, and the inner radial side of the connector matches the syringe port.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] This catheter, used to dilate the opening of severely stenotic renal arteries, is designed based on the anatomical relationship between the renal artery and the abdominal aorta. The attack section at the tip of the catheter is at a right angle or acute angle to the distal end of the abdominal aorta. The shape and elastic modulus of the attack section are defined to ensure that the tension and stress of the curved section can be transferred smoothly, making it less likely to pop out of the renal artery and easier to pass through the stenotic artery during kneading and impact.

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0021] Figure 1 This is an overall schematic diagram of a catheter for dilating the orifice of a severely stenotic renal artery, as described in this utility model.

[0022] Figure 2 This is a schematic diagram of the attack segment of a catheter used to dilate the orifice of a severely stenotic renal artery, as described in this utility model. Detailed Implementation

[0023] The following description is intended to provide a detailed account of the present invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the present invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0024] Please see Figure 1-2 This utility model provides a technical solution: a catheter for dilating the orifice of a severely stenotic renal artery. The catheter is an elastic catheter with an input port a and an output port b at its two ends. The catheter includes a straight section 100, a curved section 200, and an attack section 300 extending sequentially between the input port a and the output port b. The end of the straight section 100 away from the input port a extends radially to form the curved section 200 and the straight section 100. The angle between the axis of the attack section 300 and the axis of the straight section 100 is no greater than 90 degrees. The outer diameter of the attack section 300 gradually decreases as it approaches the output port b. Preferably, the radial cross-section of the outer side of the attack section 300 is wedge-shaped, and the elastic modulus of the curved section 200 is less than that of the attack section 300.

[0025] Clinically, some patients have stenosis at the opening of the renal artery, such as patients with aortitis. Traditional renal arteriography catheters have obtuse angles at the tip, are flexible, and have a long tip with high tension, making it difficult to pass through the stenotic end of the opening.

[0026] This catheter, used to dilate the opening of severely stenotic renal arteries, is designed based on the anatomical relationship between the renal artery and the abdominal aorta. The attack section 300 at the tip of the catheter is at a right angle or an acute angle to the distal end of the abdominal aorta. The shape and elastic modulus of the attack section 300 are defined to allow the tension and stress of the curved section 200 to be transferred smoothly, making it less likely to pop out of the renal artery and easier to pass through the stenotic artery during kneading and impact.

[0027] Furthermore, the inner wall thickness of the attack segment 300 is equal in the circumferential direction at any point in the axial direction, and the inner wall thickness of the attack segment 300 gradually decreases towards the output port b. This is to avoid the reduction in the radial outer dimension of the attack segment 300 affecting the radial inner dimension of the attack segment 300, facilitating the guide wire's insertion into the radial inner side of the attack segment 300. Combined with the aforementioned limitation on the elastic modulus of the attack segment 300, the attack segment 300 maintains rigidity while reducing its wall thickness, allowing the inner wall of the attack segment 300 to fit tightly against the guide wire, thereby enabling smoother passage through narrow sections.

[0028] In one embodiment, the inner diameter of the attack segment 300 gradually decreases as it approaches the output port b. The end of the attack segment 300 furthest from the output port b is a connecting end 300a. The difference between the inner diameter of the connecting end 300a and the inner diameter of the output port b is much smaller than the difference between the outer diameter of the connecting end 300a and the outer diameter of the output port b. In another embodiment, the inner diameter of the attack segment 300 is the same at any point along the axial direction.

[0029] To ensure the guidewire passes smoothly through the straight section 100, the curved section 200, and the attack section 300 in the catheter, the curved section 200 is further connected to the opening axis of the attack section 300 and coincides with the axis of the attack section 300; the curved section is connected to the opening axis of the straight section 100 and coincides with the axis of the straight section 100.

[0030] Regarding the fact that the elastic modulus of the bending section 200 is less than that of the attacking section 300, specifically, the conduit includes flexible and rigid components, and the elastic modulus of the bending section 200 and the attacking section 300 is controlled by adjusting the ratio of the flexible and rigid components. The elastic modulus can also be understood as the local flexibility and stiffness of the conduit.

[0031] In one embodiment, the flexible component is made of nylon and polyurethane, and the rigid component is made of steel wire and polytetrafluoroethylene (PTFE). For ease of description, PTFE is hereinafter referred to as PIFE. The polyurethane content of the bending section 200 is higher than that of the attacking section 300, while the PIFE and steel wire content of the bending section 200 is lower than that of the attacking section 300. This achieves good toughness in the bending section 200, facilitating the catheter's smooth entry into the renal artery according to its shape. Simultaneously, it ensures that the attacking section 300 closely adheres to the guidewire, smoothly passes through the stenosis, and expands the stenotic artery through the radial outer wall of the attacking section 300.

[0032] Furthermore, the angle between the axis of the attack segment 300 and the axis of the straight segment 100 is less than 90 degrees, that is, the angle between the axis of the attack segment 300 and the axis of the straight segment 100 is an acute angle, in order to adapt to lesions where the renal artery opening is at a right angle or an acute angle. Combined with the shaped curved segment 200, it is better adapted to the femoral artery puncture catheter approach, making it easier for the attack segment 300 of the catheter to enter the renal artery.

[0033] Furthermore, the length of the attack segment 300 is no more than 1 cm, preferably 1.0 cm. The attack segment 300 is shorter than that of traditional SIM1 catheters, RH catheters, or single-bend catheters, in order to better release the tension when the catheter passes through the stenotic segment and make the attack segment 300 less likely to pop out of the renal artery.

[0034] Furthermore, the attack section 300 is covered with a radiopaque coating 301, which is not easily penetrated by X-rays and is used to display the catheter position to better adapt to passing through narrow renal artery areas and clearly display the position of the catheter tip.

[0035] Furthermore, the radial cross-sectional dimension of the straight section 100 near the input port a gradually increases in a manner close to the input port a to form the connecting portion 101;

[0036] The connecting part 101 has a raised thread on its radially outer side, which matches the thread cap of the syringe pump connecting tube, and the connecting part 101 has a radially inner side that matches the syringe port.

[0037] Furthermore, the inner and outer radial sides of the catheter are covered with a hydrophilic coating to significantly reduce the friction between the guidewire and the catheter and increase the controllability of the catheter. The hydrophilic coating includes, but is not limited to, polyvinylpyrrolidone (PVP) and polyacrylamide (PAM) molecules.

[0038] Furthermore, the catheters are designed in various sizes to meet clinical practice needs, including microcatheters suitable for 0.015 inches and relatively thinner 0.018-inch catheters.

[0039] How to use:

[0040] S1. After obtaining informed consent from the patient, disinfect and drape the area. Local infiltration anesthesia is performed at the femoral artery puncture site using lidocaine. The femoral artery is punctured with a 4F puncture needle. After good blood flow, the needle is alternately inserted into the 7F arterial sheath via the guidewire. The guidewire and pigtail angiography catheter are then inserted through the arterial sheath.

[0041] S2. Using a pigtail catheter for angiography at the level of thoracic vertebra 12 to lumbar vertebra 1, the location of the renal artery opening and the level of renal artery stenosis are determined. For example, severe stenosis at the opening of the left renal artery is found to be close to occlusion.

[0042] S3. Remove the pigtail catheter and alternately insert the single-curved catheter. Position it at the opening of the narrow renal artery on the left side. It was found that the conventional catheter could not pass through the narrow area. Therefore, the catheter was positioned at the opening of the renal artery. The microguidewire was alternately inserted and repeatedly tried to make the microguidewire pass through the narrow renal artery area smoothly.

[0043] S4. The catheter is inserted along the microguidewire. The catheter follows the guidewire to the narrow area. Under the guidance of the 300-degree imaging positioning point in the attack section, the catheter is slowly kneaded and impacted back and forth to allow the catheter to pass through the narrow area smoothly. After passing through, the catheter is withdrawn and repeated several times to initially shape the narrow area and open the blood vessel.

[0044] Withdraw the microguidewire and catheter, then attempt to insert a thicker guidewire and angiography catheter, re-enter the affected renal artery, and gradually insert larger diameter catheters. Finally, when a certain extent is reached, alternately insert balloon catheters to dilate the affected blood vessel and achieve recanalization.

[0045] In summary, the optimized design of the catheter's curved and attack sections facilitates smooth insertion and impact through severely stenotic renal arteries. The application of this catheter can significantly reduce radiation exposure time and contrast agent dosage, increase patient and surgeon confidence, improve surgical success rate, and significantly enhance surgical safety.

[0046] This catheter for dilating the orifice of a severely stenotic renal artery has the following advantages:

[0047] 1. The angle between the attack segment 300 and the straight segment 100 is acute, which is suitable for cases of renal artery orifice stenosis via the femoral artery approach;

[0048] 2. The shorter 300-meter attack section reduces tension and is suitable for cases with renal artery orifice stenosis, where the catheter is less likely to be ejected from the renal artery due to high resistance;

[0049] 3. The outer side of the 300 section of the attack section is wedge-shaped, and the radial wall thickness gradually decreases, making it easier for the catheter to pass through the narrow section along the guidewire.

[0050] The embodiments described above are only used to illustrate the technical ideas and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. The scope of patent application of this utility model should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in this utility model still fall within the patent scope of this utility model.

Claims

1. A catheter for dilating the orifice of a severely stenotic renal artery, said catheter being an elastic catheter, characterized in that, The conduit has an input port (a) and an output port (b) at its two ends. The conduit includes a straight section (100), a curved section (200), and an attack section (300) extending sequentially between the input port (a) and the output port (b). The straight section (100) extends radially from the input port (a) to form the curved section (200) and the straight section (100). The angle between the axis of the attack section (300) and the axis of the straight section (100) is no greater than 90 degrees. The outer diameter of the attack section (300) gradually decreases as it approaches the output port (b). The elastic modulus of the curved section (200) is less than that of the attack section (300).

2. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 1, characterized in that, The inner wall thickness of the attack section (300) is equal in the circumferential direction at any point in the axial direction, and the inner wall thickness of the attack section (300) gradually decreases as it approaches the output port (b).

3. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 2, characterized in that, The inner diameter of the attack section (300) gradually decreases as it approaches the output port (b). The end of the attack section (300) furthest from the output port (b) is the connection end (300a). The difference between the inner diameter of the connection end (300a) and the inner diameter of the output port (b) is much smaller than the difference between the outer diameter of the connection end (300a) and the outer diameter of the output port (b).

4. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 2, characterized in that, The inner diameter of the attack section (300) is the same at any point in the axial direction.

5. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 1, characterized in that, The angle between the axis of the attack segment (300) and the axis of the straight segment (100) is less than 90 degrees.

6. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 1, characterized in that, The length of the attack segment (300) is no more than 1 cm.

7. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 1, characterized in that, The attack section (300) is covered with a radiopaque coating (301) which is configured to block X-rays.

8. A catheter for dilating the orifice of a severely stenotic renal artery according to claim 1, characterized in that, The straight section (100) near the input port (a) has a radial cross-sectional dimension that gradually increases in a manner close to the input port (a) to form a connecting part (101). The connecting part (101) has a raised thread on its radially outer side, which matches the thread cap of the injection pump connecting tube, and the connecting part (101) matches the syringe port on its radially inner side.

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