CN112439122A - Balloon dilatation catheter - Google Patents

Abstract

The invention discloses a balloon dilatation catheter which comprises a soft head, a balloon, an inner tube, a far-end outer tube, a transition tube, a hypotube and a catheter handle. The combination body of the soft head and the inner tube is arranged in and connected with the far-end neck of the saccule, and the inner tube penetrates through the inner cavity of the far-end outer tube and the inner cavity of the saccule; the distal-most end of the distal outer tube is placed into and attached to the proximal neck of the balloon. The balloon surface is provided with one or more blood flow guiding grooves along the axial direction. The inner pipe is of a multilayer structure, the outer layer is a polymer layer with gradually changed hardness, the middle layer is a metal net, and the inner layer is PTFE. The balloon is provided with the blood flow guide groove, so that the blood flow cannot be completely blocked when the balloon is inflated, and the injury caused by ischemia of a far-end blood vessel and a far-end tissue is avoided; the far ends of the saccule and the catheter are very flexible, the operation performance is good, the penetrating performance is strong, and therefore the operation is rapid, the cost is saved, and the risk to the patient is small.

Description

Balloon dilatation catheter

Technical Field

The invention belongs to medical instruments, and particularly relates to a balloon dilatation catheter.

Background

Cerebrovascular disease is the most common and serious disease threatening human life and health. Wherein, the cerebral apoplexy is the first cause of death in China. Research data shows that 330 million new stroke patients occur in China each year, the number of stroke death patients is about 170 million each year, the treatment cost for the stroke is over 100 million yuan each year in China, and heavy economic burden is caused to the nation and families. Cerebral aneurysm refers to intracranial aneurysm, with hidden course, sudden onset, and high disability and mortality rate once it occurs, and is called intracranial "sporadic bomb" which is one of the most dangerous cerebrovascular diseases. The number of new cerebral aneurysm patients in China is as much as 20 ten thousand every year. For cerebral apoplexy and cerebral aneurysm, the treatment with drugs is almost ineffective. Although the craniotomy has good curative effect, the intracranial vascular structure is complex, so that the surgery is very limited and has great risks. With the continuous development of minimally invasive interventional therapy, the interventional therapy technology of intracranial vascular diseases is more and more advanced, and methods such as intracranial vascular stent forming operation, intravascular stent thrombus removal, suction catheter thrombus removal treatment and the like have brought great benefits to patients. However, interventional procedures often involve stenotic vessels, such as when a stent or a thrombus aspiration catheter is inserted, and the stenotic vessels are likely to be unable to pass through during stent delivery, so that the stenotic vessels need to be pre-expanded by a balloon dilatation catheter for smooth passage of the stent or other therapeutic devices. Because intracranial vessels are small in tortuosity and complex in structure, the far end of the balloon dilatation catheter is required to have very good flexibility and fracture resistance. On the other hand, the balloon inflated at high pressure is closely attached to the vessel wall, so that blood flow is blocked, and then far-end blood vessel ischemia is caused, brain tissue death is caused, great risk is brought to a patient, and even the life of the patient is threatened. Thus, an ideal intracranial balloon dilation catheter should have very good compliance and resistance to flexing, while not completely blocking blood flow.

The advent of vascular stents opened a new era for vascular therapy. But In Stent Restenosis (ISR) is a significant problem. If another stent is released within the restenosis drug stent, the incidence of subsequent restenosis can be as high as 43%. The superiority of Drug-coated balloons (DCB), a combination of traditional balloon angioplasty and advanced Drug elution techniques, is increasingly shown. DCB is not only simple and convenient to operate, but also has unique advantages on stent restenosis, bifurcation lesion, small vessel lesion, severe bending calcification lesion and the like. While DCB has many potential advantages, it has several significant problems:

1. to ensure adequate penetration of the drug into the vessel or tissue, DCB is generally maintained in a full state for more than one minute, but conventional balloon dilation procedures for coronary and peripheral vessels limit balloon dilation times (blood flow blocking times) to no more than a few tens of seconds. The problems of short contact time of DCB and pathological tissues and low drug transfer rate are urgently solved.

2. Because the existing drug coating carrier material and balloon material have insufficient bonding force, the drug on the surface of the balloon is seriously lost in the intervention process.

3. The existing drug coating carrier material has general blood compatibility and can generate negative effect on blood vessel healing.

In order to solve the above problems, some modifications of the structure, composition and drug delivery manner of DCB have been made by those skilled in the art, for example, chinese patent application 201510378938.1 provides a drug balloon catheter, in which a first cavity and a second cavity are arranged in the inner cavity of the catheter body along the axial direction of the catheter body, and the first cavity and the second cavity penetrate through the catheter body where the balloon portion is arranged; wherein the first cavity is used for a guide wire to pass through; the second lumen is for the passage of blood. However, due to the design, the aperture of the second cavity is small, and the unobstructed blood flow cannot be ensured. Chinese patent application 201610186716.4 provides a balloon catheter for blocking blood flow, describing a balloon consisting of a four petal shaped balloon. This design can provide adequate blood flow lumen, but the significant drawback is that the gaps between the petal balloons are too large and the plaque or emboli that sloughed off during the vasodilation procedure can flow to and occlude the distal vessel, posing a significant risk to the patient. To address the problem of drug loss from the balloon surface during the intervention, chinese patent application 201310535041.6 describes a double-layered balloon in which one layer is a porous structure. The balloon of this design is complex in structure, very costly to manufacture, and requires many less hemocompatible chemicals, such as one of silica or starch as the filler, and hydrophilic polar monomers (one of acrylic acid, methacrylic acid, acrylamide, acrylate, methacrylate, hydroxyethyl methacrylate, vinyl acetate, or acrylonitrile).

In fact, some unsaturated fatty acids which are good in blood compatibility and beneficial to human bodies have good affinity with balloon materials, and are good in compatibility and fitting with blood vessels. For example, linoleic acid is not synthesized by humans, but it lowers blood cholesterol and prevents atherosclerosis. Omega-3 fatty acid is also very beneficial to human body, and more than 1.5 ten thousand research reports show that Omega-3 fatty acid has the characteristics of anti-inflammation, anti-thrombosis, anti-cardiac rhythm, blood fat reduction and blood vessel relaxation.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the balloon dilatation catheter which can avoid the risks brought to the patient due to balloon dilatation and far-end blood vessel ischemia. The balloon is provided with the blood flow guide groove, so that the blood flow cannot be completely blocked when the balloon is inflated, and the injury caused by ischemia of far-end blood vessels and tissues is avoided; the balloon and the balloon catheter have very soft and smooth far ends, good control performance and strong crossing performance, thereby having quick operation, cost saving and small risk to patients.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a balloon dilation catheter, comprising: the device comprises a soft head, a balloon, an inner tube, a far-end outer tube, a transition tube, a hypotube and a catheter handle;

the combination body of the soft head and the inner tube is arranged in and connected with the far-end neck of the saccule, and the inner tube penetrates through the inner cavity of the far-end outer tube and the inner cavity of the saccule; the most distal end of the distal outer tube is arranged in the proximal neck of the balloon and is connected with the proximal neck of the balloon;

the balloon main body is provided with one or more blood flow guide grooves along the axial direction;

the inner pipe is of a multilayer structure, the outer layer is a polymer layer, the middle layer is a metal mesh, and the inner layer is Polytetrafluoroethylene (PTFE).

The outer layer of the inner tube is made of nylon, a block polyether amide elastomer Pebax or Polyurethane; the middle layer is a metal woven net or a spring net.

The hardness of the material of the far end of the outer layer of the inner pipe is lower than or equal to that of the material of the near end of the outer layer of the inner pipe, and the thickness of the material of the far end of the outer layer of the inner pipe is lower than or equal to that of the material of the near end of the outer layer of the inner pipe.

A drug coating is arranged on the surface of the balloon, and comprises a bottom layer and an outer layer; wherein the bottom layer is arranged on the surface of the balloon and is a mixture of a medicament and a medicament carrier; the outer layer is arranged above the bottom layer and is a drug coating auxiliary agent.

The medicine comprises: paclitaxel, rapamycin or a derivative of rapamycin, or a platelet inhibiting drug, or a vascular endothelialization inhibiting drug, or an anti-tumor drug;

the drug carrier comprises a biodegradable high molecular material, linoleic acid or Omega-3 fatty acid.

The drug coating auxiliary agent comprises: urea, iopromide, alcohols, amino acids or polyunsaturated fatty acids.

The far-end outer tube has a double-layer structure, and the outer layer is made of nylon or a block polyether amide elastomer Pebax or Polyurethane; the inner layer is a metal woven net or a spring net.

The far-end outer tube has a double-layer structure, and the outer layer is made of a block polyether amide elastomer Pebax or Polyurethane or ePTFE with low hardness; the inner layer is made of high-hardness nylon.

The outer surfaces of the distal outer tube and the transition tube are provided with hydrophilic coatings.

The invention has the beneficial effects that:

according to clinical requirements, the advantages of the scheme of the invention are summarized as follows:

1) when the balloon is used for dilating the narrow blood vessel, the blood flow can not be completely blocked due to the blood flow guide groove, so that the injury caused by ischemia of the far-end blood vessel and tissue is avoided;

2) the balloon and the far end of the balloon catheter are very flexible, the catheter has strong crossing performance, excellent bending resistance, good control performance, quick operation, small risk to patients and cost saving.

Drawings

FIG. 1 is a block diagram of a balloon dilation catheter;

FIG. 2 is a cross-sectional view of the balloon with a blood flow directing groove;

FIG. 3 is a cross-sectional view of another balloon with a blood flow directing groove;

FIG. 4 is a cross-sectional view of the balloon with two blood flow guide slots;

FIG. 5 is a schematic view of an inner tube of the present invention;

in the figure, 1. soft head; 2. a balloon; 3. a blood flow guide groove (balloon recess); 4. an inner tube; 5. a distal outer tube; 6, a transition pipe; 7. a hypotube; 8, supporting the stress tube; 9. a handle; 10. a hydrophilic coating; 11. and (4) coating the medicine.

Detailed Description

Example 1

As shown in fig. 1, the balloon dilation catheter of the embodiment includes: the device comprises a soft head 1, aballoon 2, a bloodflow guide groove 3, aninner tube 4, a distalouter tube 5, atransition tube 6, ahypotube 7, astress support tube 8, acatheter handle 9, ahydrophilic coating 10 and adrug coating 11.

The combination of the soft head 1 and theinner tube 4 is arranged in and connected with the neck part at the far end of theballoon 2, and theinner tube 4 penetrates through the inner cavity of the far-endouter tube 5 and the inner cavity of theballoon 2; the farthest end of the far-endouter tube 5 is placed in the neck part of the near end of theballoon 2 and is connected with the neck part of the near end of theballoon 2, so that the far-endouter tube 5 is communicated with theballoon 2;

thecatheter handle 9 is connected with the far-endouter tube 5 through thehypotube 7 and thetransition tube 6 and is communicated with the far-endouter tube 5, theballoon 2 can be filled at high pressure by injecting liquid from the filling cavity of thecatheter handle 9, and thestress support tube 8 is further arranged between thecatheter handle 9 and thehypotube 7 so as to ensure the anti-bending performance between thecatheter handle 9 and thehypotube 7.

As shown in fig. 2, 3 and 4, the main body of theballoon 2 is provided with one or more bloodflow guiding grooves 3 along the axial direction, i.e. the outer surface of the balloon has depressions when inflated. The balloon is provided with a blood flow guide groove, so that the filled balloon can not completely block blood flow, and the injury to far-end blood vessels and tissues is avoided;

theinner tube 4 is of a multilayer structure, and the outer layer is a high polymer layer with gradually-changed hardness, or nylon or a block polyether amide elastomer Pebax or Polyurethane; the middle layer is a metal reinforcing mesh or a spring mesh, and the inner layer is ultra-smooth PTFE, or high density polyethylene HDPE, or block polyether amide elastomer Pebax containing a friction coefficient reducing additive.

The outer surface of the distalouter tube 5 and thetransition tube 6 is provided with ahydrophilic coating 10.

Theballoon 2 surface may also be provided with adrug coating 11.

The far-endouter tube 5 has a double-layer structure, and the outer layer is made of nylon or a block polyether amide elastomer Pebax or Polyurethane; the inner layer is a metal woven net or a spring net.

The distalouter tube 5 may also be used: the outer layer is made of a low-hardness block polyether amide elastomer Pebax or Polyurethane or ePTFE; the inner layer is made of high-hardness nylon.

The soft head 1, theballoon 2, theinner tube 4 and the distalouter tube 5 at the distal end of the balloon dilatation catheter are very flexible, good in control performance and strong in crossing performance, so that the operation is fast, the cost is saved, and the risk to patients is small.

When the balloon dilatation catheter is used, a proper guide wire is pushed to a far-end blood vessel narrow section, the guide wire penetrates through a guide wire opening, the balloon dilatation catheter is pushed to enter a diseased blood vessel along the guide wire, when theballoon 2 in an unfilled state reaches the narrow section, liquid is injected from acatheter handle 9 filling cavity, the high-pressure filled balloon expands the narrow blood vessel, meanwhile, themedicine coating 11 on the surface of the balloon is attached to the blood vessel wall, and in order to transfer more medicines to the blood vessel wall and promote the medicine molecules to diffuse into the blood vessel wall, theballoon 2 is kept in a filled state for at least 2 minutes. Because thesaccule 2 is provided with the two axial blood flow guide grooves 3 (as shown in fig. 3), the blood flow is not blocked in the drug transfer process, and the far-end blood vessel and the brain tissue cannot be damaged; on the other hand, since the axial blood flow guide groove is provided with a small cross section, a large thrombus is intercepted, and thus does not flow into and block the distal blood vessel.

Example 2

Based on example 1, theinner tube 4 of the balloon dilation catheter of the present invention is shown in fig. 5, and includes an outer layerproximal end 44, an outer layerdistal end 43, a circular tubularintermediate metal mesh 42, and an ultra-thin Polytetrafluoroethylene (PTFE) tubeinner layer 41. The guidewire passes through theguidewire lumen 12 to the distal vascular stenosis.

The wall thickness of the outer layer material of theinner tube 4 is gradually reduced or equal from the proximal end to the distal end, the outer diameter of theinner tube 4 is also gradually reduced or equal from the proximal end to the distal end, and the hardness of theinner tube 4 is also gradually reduced or equal from the proximal end to the distal end.

The material of thenear end 44 of the outer layer of the inner tube is nylon or Pebax with higher hardness, and the material of thefar end 43 of the outer layer of the inner tube is Pebax with lower hardness; the inner tube with the intermediate expandedmetal 42 is superior in bending resistance, and such a design is well suited for very tortuous and soft cerebral vessels.

The woven mesh of the intermediate wire netting 42 is made of one or more of the following wire materials, including but not limited to: 1) Titanium alloy with tweezers; 2) A cobalt chromium alloy; 3) Stainless steel; 4) Pure platinum and its alloys; 5) Pure tungsten and its alloys. The wire material of the metal wire is a round wire or a flat wire. The diameter of the round wire, the thickness of the flat wire and the width are between 5 and 500 micrometers. The mesh grid can also be made of polymer wires made of nylon, PEEK, Liquid Crystal polymer or silicone rubber.

Example 3

As shown in fig. 1, on the basis of embodiment 1, adrug coating 11 is disposed on the surface of theballoon 2, and thedrug coating 11 includes a bottom layer and an outer layer; wherein the bottom layer is arranged on the surface of the balloon and is a mixture of a medicament and a medicament carrier; the outer layer is arranged above the bottom layer and is a drug coating auxiliary agent.

The medicine is paclitaxel, rapamycin or rapamycin derivative, the drug-loading rate is 1-6 microgram/square millimeter, and can also be platelet inhibiting medicine, vascular endothelialization inhibiting medicine or antitumor medicine. The drug coating thickness is between 5-100 microns. The drug carrier is a material having good affinity with both the balloon material and the vessel wall, such as a biodegradable polymer material, or linoleic acid and Omega-3 fatty acid. The drug coating auxiliary agent is urea, iopromide, alcohol substances or amino acid or polyunsaturated fatty acid.

When theballoon 2 of the invention reaches the stenosis section, the liquid is injected from the filling cavity of thecatheter handle 9, the balloon filled at high pressure expands the stenotic vessel, and thedrug coating 11 on the surface of theballoon 2 is transferred and attached to the vessel wall because the carrier material and the vessel wall also have good affinity.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims (9)

1. A balloon dilation catheter, comprising: the device comprises a soft head, a balloon, an inner tube, a far-end outer tube, a transition tube, a hypotube and a catheter handle;

the combination body of the soft head and the inner tube is arranged in and connected with the far-end neck of the saccule, and the inner tube penetrates through the inner cavity of the far-end outer tube and the inner cavity of the saccule; the most distal end of the distal outer tube is arranged in the proximal neck of the balloon and is connected with the proximal neck of the balloon;

the balloon main body is provided with one or more blood flow guide grooves along the axial direction;

the inner pipe is of a multilayer structure, the outer layer is a polymer layer, the middle layer is a metal mesh, and the inner layer is Polytetrafluoroethylene (PTFE).

2. The balloon dilation catheter according to claim 1 wherein the outer layer of the inner tube is nylon, a block polyetheramide elastomer Pebax or Polyurethane; the middle layer is a metal woven net or a spring net.

3. The balloon dilation catheter according to claim 1 wherein the hardness of the inner tube outer layer distal material is lower than or equal to the hardness of the inner tube outer layer proximal material and the thickness of the inner tube outer layer distal material is lower than or equal to the thickness of the inner tube outer layer proximal material.

4. The balloon dilation catheter of claim 1 wherein a balloon surface is provided with a drug coating comprising a bottom layer and an outer layer; wherein the bottom layer is arranged on the surface of the balloon and is a mixture of a medicament and a medicament carrier; the outer layer is arranged above the bottom layer and is a drug coating auxiliary agent.

5. The balloon dilation catheter of claim 4 wherein the medicament comprises: paclitaxel, rapamycin or a derivative of rapamycin, or a platelet inhibiting drug, or a vascular endothelialization inhibiting drug, or an anti-tumor drug;

the drug carrier comprises a biodegradable high molecular material, linoleic acid or Omega-3 fatty acid.

6. The balloon dilation catheter of claim 4 wherein the drug coating adjuvant comprises: urea, iopromide, alcohols, amino acids or polyunsaturated fatty acids.

7. The balloon dilatation catheter of claim 1 or 4 wherein the distal outer tube has a double layer structure with an outer layer of material selected from nylon or a block polyetheramide elastomer Pebax or Polyurethane; the inner layer is a metal woven net or a spring net.

8. The balloon dilatation catheter of claim 1 wherein the distal outer tube has a double layer structure with outer layer material of low durometer block polyetheramide elastomer Pebax or Polyurethane or ePTFE; the inner layer is made of high-hardness nylon.

9. The balloon dilation catheter of claim 1 wherein the distal outer tube and transition tube outer surface have a hydrophilic coating.

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