Novel microcatheter

Abstract

The utility model discloses a novel micro catheter, and belongs to the field of medical instruments. Comprising a microcatheter body, the microcatheter body comprises an inner catheter layer, a middle layer and an outer sleeve layer, the middle layer is connected with the inner catheter layer and the outer sleeve layer, the microcatheter is characterized in that the outer sleeve layer is composed of a plurality of splicing sections, and the adjacent splicing sections of the splicing sections are spliced in a staggered mode. The outer sleeve layer is provided with the multiple splicing sections and the middle layer, the multiple splicing sections can be made of different materials according to needs, the size of the catheter is not changed, and the adhesion, smoothness, flexibility, torsion control, fracture resistance, tensile resistance and ellipticity resistance of the multi-layer structure such as the inner catheter layer, the middle layer and the outer sleeve layer can be remarkably improved; and an excellent clinical use effect is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of medical equipment, and particularly relates to a micro-catheter structure. Background Art

[0002] Cardiovascular and cerebrovascular diseases are a general term for cardiovascular and cerebrovascular diseases, and refer to ischemic or hemorrhagic diseases of the heart, brain and systemic tissues caused by hyperlipidemia, blood viscosity, atherosclerosis, hypertension, etc., which can cause patients to have symptoms such as palpitations, chest pain, headache, vomiting, hemiplegia of one limb, and in severe cases, angina pectoris and organ dysfunction may occur and even lead to death, endangering the patient's life safety.

[0003] In recent years, the treatment of cardiovascular and cerebrovascular diseases has been developing towards precise and minimally invasive interventional treatment. Interventional treatment is a minimally invasive therapy that uses puncture needles, catheters and other interventional equipment under the guidance of advanced imaging equipment to accurately place specific instruments into the site of cardiovascular and cerebrovascular lesions through natural channels or tiny incisions in the human body for operation and treatment. Because its treatment process is minimally invasive, visualized and precise, it has the advantages of less trauma, multiple indications, definite efficacy and rapid postoperative recovery. It has now become one of the important means of clinical treatment of cardiovascular and cerebrovascular diseases. Microcatheters are used in vascular interventional treatment to establish a pathway for the delivery of instruments from outside the body to the target site of the blood vessel (lesion site). They are mainly used to deliver diagnostic instruments (such as contrast agents, etc.) and therapeutic instruments (such as coils, embolic agents, stents, etc.) into blood vessels. They are also used for guidewire support / exchange and passing lesions.

[0004] Microcatheters have now developed into multi-layer composite structures, which are generally divided into a smooth inner layer, a multi-layer reinforced middle layer (woven or wrapped with metal wire) and an outer layer. They have a multi-section tube body and hardness design. The proximal end is hard and provides support, which has good pushability. The distal end is soft and can pass through curved bifurcated blood vessels and lesions. The multi-layer reinforced middle layer can enhance the strength, folding resistance and pushing force of the catheter. However, with the continuous development of minimally invasive surgical technology, the complexity of cases continues to increase, the application of multi-layer reinforced catheters is becoming more and more extensive, and the comprehensive performance requirements for microcatheters are becoming higher and higher. Microcatheters have shown many shortcomings in the interventional treatment of cardiovascular and cerebrovascular diseases.

[0005] First, the filling of the gap in the reinforcement layer inside each section of the hardness tube body is completely determined by a single section of the outer jacket material, and the material of each section of the outer jacket material is fixed and cannot be changed to multiple materials (two or more) or other substances. This makes the hardness transition between different hardness sections of the microcatheter tube body change in a step-like manner, and the flexibility and smoothness are insufficient.

[0006] Secondly, the permeability of the outer jacket material into the middle reinforcement layer is limited. When the thermal welding permeability of the outer jacket material of two adjacent hardness sections is poor, the gap between the reinforcement layers is not completely filled, and the hardness between each section of the pipe body changes more suddenly, making the catheter twist control poor. Furthermore, the outer jacket hot melt cannot fully fill the gap between the reinforcement layers, especially when the pipe body has two reinforcement layers, or the two reinforcement layers are close together, the layers of the pipe body are not completely fused, and the reinforcement layer is not firmly bonded to the inner and outer layer materials, resulting in a decrease in flexural resistance, tensile resistance and elliptical resistance.

[0007] Therefore, it is of great significance to adopt new technologies and processes to develop new microcatheters to improve the efficacy of interventional treatment of cardiovascular and cerebrovascular diseases. Utility Model Content

[0008] In order to solve the above problems, the primary purpose of the utility model is to provide a new type of microcatheter, which increases the flexibility of the tube body, reduces the hardness difference between different hardness sections of the tube body, reduces the breakage and delamination between the layers of the tube body, and improves the adhesion, smoothness, torsion control, folding resistance, tensile resistance and elliptical resistance of the catheter multi-layer structure.

[0009] To achieve the above purpose, the technical solution of the utility model is as follows:

[0010] The utility model provides a novel microcatheter, comprising a microcatheter body, wherein the microcatheter body comprises an inner catheter layer, an intermediate layer and an outer jacket layer, wherein the intermediate layer is arranged between the inner catheter layer and the outer jacket layer, and the outer jacket layer is composed of a plurality of splicing sections, and adjacent splicing sections are staggered and spliced.

[0011] Furthermore, the middle layer includes a reinforcement layer and a gap filling layer, wherein the gap filling layer is formed to fill the gap of the reinforcement layer. Wherein, the inner conduit layer is preferably a smooth inner layer.

[0012] Furthermore, the outer jacket layer includes a proximal end, a distal end, and two or more splicing sections, wherein the splicing section is located between the proximal end and the distal end, and a splicing notch is provided between adjacent splicing sections for increasing the splicing area. The design of the splicing notch can increase the contact area between adjacent splicing sections, making the outer jacket layer more firmly welded and not easy to separate.

[0013] Furthermore, the multi-layer reinforcement layer includes a first reinforcement layer and a second reinforcement layer, a first filling gap is provided in the first reinforcement layer, a second filling gap is provided on the second reinforcement layer, and the gap filling layer includes a first filling gap and a second filling gap. The above-mentioned method of pre-filling the gaps in the first reinforcement layer and the second reinforcement layer can ensure that the filling gaps of the first reinforcement layer and the second reinforcement layer are completely filled, and also play a bonding role for the inner catheter layer and the outer jacket layer, so that the various layers of the catheter body are more tightly bonded and better integrated into one, reducing the risk of delamination and fracture between the layers during use, and improving the adhesion, smoothness, folding resistance, tensile strength and elliptical resistance of the multi-layer structure of the tube body. It overcomes the problem in the prior art that the permeability of the outer jacket layer material into the reinforcement layer is limited, and when the hot welding permeability of the outer layer material of the two adjacent hardness sections is poor, the gaps in the reinforcement layer are not completely filled, and the hardness between each section of the tube body is more abrupt, resulting in poor torsional control of the catheter. Furthermore, the problem that the hot melt of the outer sleeve cannot fully fill the gap in the reinforcement layer is overcome, especially when the pipe body has two reinforcement layers, or the two reinforcement layers are closely attached, the layers of the pipe body are not completely fused, and the reinforcement layer is not firmly bonded to the inner and outer layer materials, resulting in a decrease in the bending resistance, tensile resistance and ovality resistance.

[0014] Furthermore, the two or more splicing sections are respectively composed of thermoplastic polymer materials of different hardness, and the hardness of the splicing section decreases from the proximal end to the distal end. The above arrangement can achieve a mixed hot-melt connection of two outer jacket materials during hot-melt welding of the reinforcement layer within the transition length of the two splicing sections, thereby reducing the hardness difference between the tube body sections and improving the smoothness and flexibility of the catheter. This overcomes the problem of the prior art that the gap filling of the reinforcement layer in each tube body of the current microcatheter is determined by a single outer jacket material and filled by hot-melt filling of the outer jacket, which is filled with only one material, causing the hardness of the tube body to change in a step-like manner and the tube body to be not smooth and flexible enough.

[0015] Furthermore, the thermoplastic polymer material includes one or more of polyamide, polyurethane, polyether and nylon.

[0016] In the present invention, the middle layer can be set as a multi-layer reinforcement layer, and the middle layer includes three types: a multi-layer reinforcement layer with gap filling, a multi-layer reinforcement layer with gap filling, and a metal wire multi-layer reinforcement layer pre-coated with a polymer material. The gap filling and polymer materials different from the outer layer and the inner catheter layer materials can be selected as needed, which not only does not change the catheter size, but also can significantly improve the adhesion, smoothness, flexibility, torsion control, folding resistance, tensile resistance and elliptical resistance of the multi-layer structure such as the inner catheter layer, the middle layer and the outer layer, so as to achieve excellent clinical use effects. The gap filling material can be selected from flexible polymer materials such as TPU and silica gel, which can be completed by hot melting, dipping, coating and welding, and can be filled before or after the reinforcement layer is combined with the inner catheter layer.

[0017] Furthermore, the first reinforcement layer and the second reinforcement layer are both formed by braiding or winding metal wires. The metal wires can be made of stainless steel, nickel titanium and tungsten. The permeability of the inner lining layer or outer sleeve material of the traditional microcatheter into the reinforcement layer by hot melting is limited, and after the two reinforcement layers are combined, especially when the two reinforcement layers are in close contact, the inner lining layer or outer sleeve is difficult to melt into the gap between the reinforcement layers and the gap between the reinforcement layer and the inner and outer layers during the hot welding process. The infiltration filling is insufficient, resulting in poor fusion between the layers of the tube body, and the reinforcement layer is not firmly bonded to the inner and outer layer materials. Furthermore, by filling the gap between the reinforcement layers of the tube body by hot welding, the rebound force of the metal wires of the reinforcement layer will directly act on the smooth inner layer and the outer sleeve, causing the layers of the catheter body to separate. The first reinforcement layer and the second reinforcement layer in the utility model are both formed by braiding or winding metal wires, and combined with gap filling, it can well solve the problems existing in traditional microcatheters. The gap filling can fully fill the gap between the first reinforcement layer and the second reinforcement layer in advance, and also play a bonding role for the inner catheter layer and the outer jacket layer, so that the various layers of the microcatheter body are more tightly bonded and better integrated into one, reducing the risk of delamination and fracture between the layers during use, and improving the adhesion, smoothness, folding resistance, tensile resistance and elliptical resistance of the multi-layer structure of the tube body.

[0018] Furthermore, the microcatheter also includes a catheter seat and a stress relief tube, and the stress relief tube is sleeved at the connection between the proximal end of the outer jacket layer and the catheter seat.

[0019] Furthermore, the inner catheter layer is made of a material with a low friction coefficient, including high-density polyethylene, polytetrafluoroethylene, etc. The above material setting can make it smoother to assist other instruments to pass through.

[0020] The advantage of the utility model is that, compared with the prior art, the outer jacket layer is configured as multiple spliced ​​segments and an intermediate layer is configured, so that the multiple spliced ​​segments can be configured to be made of different materials as needed, not only without changing the size of the catheter, but also significantly improving the adhesion, smoothness, flexibility, torsion control, folding resistance, tensile strength and elliptical resistance of the multi-layer structure such as the inner catheter layer, the intermediate layer and the outer jacket layer, thereby achieving excellent clinical use effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model.

[0022] Figure 2 It is a structural schematic diagram of the utility model in which the splicing gap of the outer jacket layer is a grain-shaped incision.

[0023] Figure 3 It is a structural schematic diagram of the utility model in which the splicing gap of the outer jacket layer is a serrated incision.

[0024] Figure 4It is a structural schematic diagram of the utility model in which the splicing notch of the outer jacket layer is an oblique cut.

[0025] Figure 5 It is a schematic diagram of the hierarchical structure of each layer of the microcatheter main body of the utility model.

[0026] Figure 6 The utility model micro-catheter main body is Figure 5 Schematic diagram of the cross-sectional structure along the AA direction. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0028] See also Figure 1-6 The present embodiment provides a novel microcatheter, comprising a microcatheter body 1, wherein the microcatheter body 1 comprises an inner catheter layer 11, an intermediate layer 12 and an outer jacket layer 13, wherein the intermediate layer 12 is arranged between the inner catheter layer 11 and the outer jacket layer 13, wherein the inner catheter layer 11, the intermediate layer 12 and the outer jacket layer 13 are sequentially arranged from the inside to the outside, wherein the outer jacket layer 13 is composed of a plurality of splicing segments 133, wherein adjacent splicing segments 133 of the plurality of splicing segments 133 are staggered and spliced.

[0029] The inner conduit layer 11 is preferably a smooth inner layer. The gap filling layer 121 can be made of flexible polymer materials such as TPU and silicone, and can be completed by hot melting, dipping, coating and welding, and can be filled before or after the reinforcing layer 122 is combined with the inner conduit layer 11.

[0030] By configuring the outer jacket layer 13 to be composed of multiple splicing segments 133 and configuring the middle layer 12, the multiple splicing segments 133 can be configured to be made of different materials as needed, which not only does not change the size of the catheter, but also significantly improves the adhesion, smoothness, flexibility, torsion control, folding resistance, tensile strength and elliptical resistance of the multi-layer structure of the inner catheter layer 11, the middle layer 12 and the outer jacket layer 13, thereby achieving excellent clinical use effects.

[0031] In this embodiment, the intermediate layer 12 includes a gap filling layer 121 and at least one reinforcement layer 122 . The reinforcement layer 122 has a filling gap, and the gap filling layer 121 fills the filling gap.

[0032] In this embodiment, the reinforcing layer 122 includes a first reinforcing layer 1221 and a second reinforcing layer 1222, a first filling gap 2 is provided in the first reinforcing layer 1221, a second filling gap 3 is provided on the second reinforcing layer 1222, and the gap filling layer 121 includes the first filling gap 2 and the second filling gap 3. The above-mentioned method of pre-filling the gap filling layer 121 in the first reinforcing layer 1221 and the second reinforcing layer 1222 can ensure that the filling gaps of the first reinforcing layer 1221 and the second reinforcing layer 1222 are completely filled, so as to avoid the limited permeability of the existing microcatheter outer layer material when hot-melting into the middle reinforcing layer, when the outer layer material of two adjacent hardness sections has poor hot welding permeability, the gap in the middle reinforcing layer is not completely filled, resulting in abrupt hardness changes between each section of the tube body and poor catheter torsion control. Furthermore, the problem that the hot melt of the outer sleeve cannot fully fill the gap in the reinforcement layer is overcome, especially when the pipe body has two reinforcement layers, or the two reinforcement layers are closely attached, the layers of the pipe body are not completely fused, and the reinforcement layer is not firmly bonded to the inner and outer layer materials, resulting in a decrease in the bending resistance, tensile resistance and ovality resistance.

[0033] In this embodiment, the outer jacket layer 13 includes a distal end 131, a proximal end 132, and two or more splicing sections 133, wherein the splicing sections 133 are located between the distal end 131 and the proximal end 132, and splicing notches 4 for increasing the splicing area are provided between adjacent splicing sections 133. The design of the splicing notches 4 can increase the contact area between adjacent splicing sections 133, so that the outer jacket layer 13 is welded more firmly and is not easy to separate.

[0034] In this embodiment, the splicing notch 4 includes a corrugated notch, a serrated notch and an oblique notch.

[0035] In this embodiment, the two or more splicing sections 133 are respectively composed of thermoplastic polymer materials with different hardness, and the hardness of the splicing section 133 decreases from the proximal end 132 to the distal end 131. The above arrangement can achieve that the 122 reinforcement layer within the splicing transition length range of the two splicing sections 133 has a mixed hot-melt connection of two jacket layer 13 materials during hot-melt welding, thereby reducing the hardness difference between the pipe body sections and improving the smoothness and flexibility of the catheter.

[0036] In this embodiment, the thermoplastic polymer material includes one or more of polyamide, polyurethane, polyether and nylon.

[0037] In the present embodiment, the first reinforcement layer 1221 and the second reinforcement layer 1222 are both formed by braiding or winding metal wires. The metal wires can be made of stainless steel, nickel titanium and tungsten. The permeability of the inner lining layer or outer sleeve material of the traditional microcatheter into the reinforcement layer by hot melting is limited, and after the two reinforcement layers are combined, especially when the two reinforcement layers are close together, the inner lining layer or outer sleeve is difficult to melt into the gap between the reinforcement layers and the gap between the reinforcement layer and the inner and outer layers during the hot welding process, and the penetration filling is insufficient, resulting in poor fusion between the layers of the tube body, and the reinforcement layer is not firmly bonded to the inner and outer layer materials. Furthermore, by filling the gap between the reinforcement layers of the tube body by hot welding, the rebound force of the metal wire of the reinforcement layer will directly act on the smooth inner layer and the outer layer, causing the layers of the catheter body to separate. The first reinforcement layer 1221 and the second reinforcement layer 1222 in the utility model are both formed by braiding or winding metal wires, and combined with the gap filling layer 121, it can well solve the problems existing in the traditional microcatheter. The gap filling layer 121 can fully fill the gap between the first reinforcement layer 1221 and the second reinforcement layer 1222 in advance, and also play a bonding role for the inner catheter layer 11 and the outer jacket layer 13, so that the various layers of the microcatheter body are more tightly bonded and better integrated into one, reducing the risk of delamination and fracture between the layers during use, and improving the adhesion, smoothness, folding resistance, tensile resistance and elliptical resistance of the multi-layer structure of the tube body.

[0038] In this embodiment, the microcatheter further comprises a catheter seat 5 and a stress relief tube 6, and the two ends of the stress relief tube 6 are respectively connected to the catheter seat 5 and the proximal end 132 of the microcatheter body 1. The catheter seat 5 conforms to the ergonomic design, and is in a three-dimensional cone shape as a whole, which is easier to rotate, improves the clinical operation feel, and the surface shape design is more convenient for clinical physicians to hold. The catheter seat 5 is made of hard and transparent polycarbonate, polyamide or polyurethane material, and the proximal cross-section of the tube body is expanded into a trumpet shape, and then it is inserted into the inner hole of the catheter seat, and then connected to the tube body with glue. The stress relief tube 6 is made of a soft elastomeric material, such as polyurethane elastomer, polyolefin or polyethylene elastomer, and the stress relief tube 6 is sheathed at the connection between the proximal tube body and the Luer seat.

[0039] In this embodiment, the inner catheter layer 11 is made of a material with a low friction coefficient, including high-density polyethylene, polytetrafluoroethylene, etc. The above material configuration can make it smoother and assist other instruments to pass through.

[0040] The outer layer 13 material contains developing material, which can ensure the X-ray development of the tube body. The outer layer 13 is fused into one by heat welding.

[0041] The above detailed description of the preferred implementation methods of this patent is only a preferred embodiment of the utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A novel microcatheter, comprising a microcatheter body, wherein the microcatheter body comprises an inner catheter layer, an intermediate layer and an outer jacket layer, wherein the intermediate layer is arranged between the inner catheter layer and the outer jacket layer, and wherein: The outer shell layer is composed of a plurality of splicing sections, and adjacent splicing sections of the plurality of splicing sections are spliced ​​alternately.

2. The novel microcatheter according to claim 1, characterized in that: The outer shell layer comprises a proximal end, a distal end and more than two splicing sections, wherein the splicing sections are located between the proximal end and the distal end, and splicing gaps are arranged between adjacent splicing sections.

3. The novel microcatheter according to claim 1, characterized in that: The intermediate layer includes a reinforcement layer and a gap filling layer, and the gap filling layer is formed to fill the gap of the reinforcement layer.

4. The novel microcatheter according to claim 3, characterized in that: The reinforcement layer includes a first reinforcement layer and a second reinforcement layer, and a filling gap is provided in each of the first reinforcement layer and the second reinforcement layer.

5. The novel microcatheter according to claim 1, characterized in that: The two or more splicing sections are respectively composed of thermoplastic polymer materials with different hardness, and the hardness of the splicing sections decreases from the proximal end to the distal end.

6. The novel microcatheter according to claim 5, characterized in that: The thermoplastic polymer material includes one or more of polyamide, polyurethane, polyether and nylon.

7. The novel microcatheter according to claim 4, characterized in that: The first reinforcement layer and the second reinforcement layer are both formed by weaving or winding metal wires.

8. The novel microcatheter according to claim 1, characterized in that: The micro-catheter also comprises a catheter seat and a stress relief tube, wherein the stress relief tube is sleeved at the connection between the proximal end of the outer jacket layer and the catheter seat.

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