CN116350302A

CN116350302A - Thrombolysis catheter

Info

Publication number: CN116350302A
Application number: CN202111627394.XA
Authority: CN
Inventors: 陈泉; 史浩
Original assignee: Hangzhou Wei Qiang Medical Technology Co ltd
Current assignee: Hangzhou Wei Qiang Medical Technology Co ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-06-30

Abstract

The invention provides a thrombolytic catheter. The thrombolysis catheter comprises a main body section and a thrombolysis section, wherein the inner cavity of the thrombolysis section is communicated with the inner cavity of the main body section; the thrombolytic segment is switchable between a straight state and a helical state, the thrombolytic segment forming a helical structure when the thrombolytic segment is in the helical state. The side wall of the thrombolysis section is provided with a first through hole group and a second through hole group, the first through hole group comprises a plurality of first through holes communicated with the inner cavity of the thrombolysis section, and the second through hole group comprises a plurality of second through holes communicated with the inner cavity of the thrombolysis section. When the thrombolytic section is in a spiral state, the first through hole groups and the second through hole groups are respectively distributed on the thrombolytic section in a spiral mode, and each first through hole is provided with a second through hole which is located on the same circumference and is arranged in a radial opposite mode. The invention provides a thrombolytic catheter with wide administration range and good thrombolytic effect.

Description

Thrombolysis catheter

Technical Field

The invention relates to the field of medical instruments, in particular to a thrombolysis catheter.

Background

At present, for the medical treatment of intravascular thrombosis, a minimally invasive interventional technique is generally adopted, and common minimally invasive interventional techniques for treating intravascular thrombosis comprise a thrombus aspiration method and a drug thrombolysis method. The thrombus sucking method adopts a suction catheter, a 5in6 catheter and the like, and takes the suction catheter as an example, the suction catheter is introduced into the thrombus position of a lesion blood vessel from the blood vessel of the upper limb/lower limb of a patient, the thrombus is sucked out by utilizing the negative pressure at the distal end of the catheter, and the suction catheter is repeatedly pushed to the thrombus position to suck the thrombus under the condition that the thrombus is sticky and difficult to suck out. However, the self-made drug delivery device has a lot of defects, such as small delivery range and poor thrombolysis effect.

Disclosure of Invention

The invention provides a thrombolytic catheter which has wide administration range and good thrombolytic effect.

The thrombolytic catheter includes a main body section and a thrombolytic section. The body section has a lumen extending axially therethrough and extending through the proximal and distal ends thereof. The thrombolysis section is connected with the far end of the main body section, and the inner cavity of the thrombolysis section is communicated with the inner cavity of the main body section; the thrombolytic section can be switched between a straight state and a spiral state, when the thrombolytic section is in the spiral state, the thrombolytic section forms a spiral structure, and the spiral center line of the spiral structure is coincident with or parallel to the axis of the main body section. The side wall of the thrombolysis section is provided with a first through hole group and a second through hole group, the first through hole group comprises a plurality of first through holes communicated with the inner cavity of the thrombolysis section, and the second through hole group comprises a plurality of second through holes communicated with the inner cavity of the thrombolysis section. When the thrombolytic section is in a spiral state, the first through hole group and the second through hole group are respectively spirally distributed on the thrombolytic section, and each first through hole is provided with a second through hole which is positioned on the same circumference and is arranged in a radial opposite way.

It can be understood that the first through hole group and the second through hole group are arranged on the thrombolytic section, and when the thrombolytic section is in a spiral state, the first through hole group and the second through hole group are respectively spirally distributed on the thrombolytic section, and each first through hole is provided with a second through hole which is positioned on the same circumference and is arranged in a radial opposite way. That is, the plurality of first through holes and second through holes can be spirally distributed along the spiral structure, so that the layout range of the first through holes and the second through holes in space is expanded, the acting direction of thrombolytic liquid is expanded, the thrombolytic section can spray thrombolytic liquid towards thrombus in a plurality of directions around the thrombolytic section through the first through hole group and the second through hole group, the administration range is increased, the contact range of thrombolytic liquid and thrombus is further increased, and the thrombolytic effect is enhanced. The design of the thrombolysis section enables a plurality of through holes arranged in the thrombolysis section to have different thrombolysis liquid outflow directions, and the thrombolysis section is not only limited to outflow around a substantially linear pipe diameter, so that the contact area between thrombolysis liquid and thrombus is increased, thereby improving the thrombolysis effect of an operation and increasing the success rate of the operation.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a thrombolytic catheter according to an embodiment of the present invention;

FIG. 2 is a schematic view of a portion of the thrombolytic catheter shown in FIG. 1;

FIGS. 3-4 are schematic views of a thrombolytic catheter being implanted in a vascular thrombus site;

FIG. 5 is a schematic view of the thrombolytic catheter of FIG. 1 at another angle;

FIG. 6 is a schematic view of the thrombolytic section of the thrombolytic catheter of FIG. 5 at another angle;

FIG. 7 is a schematic view of the thrombolytic segment of the structure of FIG. 5in a straight state;

fig. 8 is a schematic cross-sectional view of the thrombolytic segment of the structure shown in fig. 5in a straight state.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without undue burden, are within the scope of the invention.

Furthermore, the following description of the embodiments refers to the accompanying drawings, which illustrate specific embodiments in which the invention may be practiced. Directional terms, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", etc., in the present invention are merely referring to the directions of the attached drawings, and thus, directional terms are used for better, more clear explanation and understanding of the present invention, rather than indicating or implying that the apparatus or element being referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "disposed on … …" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; may be a mechanical connection; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements.

In the field of interventional medical devices, the proximal end refers to the end closer to the operator and the distal end refers to the end farther from the operator; the axial direction refers to the direction parallel to the connecting line of the distal center and the proximal center of the medical instrument, the radial direction refers to the direction along the diameter or radius, the radial direction and the axial direction are mutually perpendicular, and the circumferential direction refers to the circumferential direction around the central axis. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a thrombolytic catheter according to an embodiment of the present invention.

The thrombolytic catheter 100 provided in this embodiment may be used to access a body cavity of a patient, such as into a blood vessel of the patient. Thrombolytic catheter 100 may be used to treat lesions in a blood vessel, such as to remove thrombi from a blood vessel. Of course, thrombolytic catheter 100 may also be used to treat lesions within a blood vessel or other lumen.

Thrombolytic catheter 100 includes a main body section 10, a thrombolytic section 20, and a connector 30. The thrombolytic segment 20 is connected to the distal end of the body segment 10 and the connector 30 is connected to the proximal end of the body segment 10. The main body section 10, thrombolytic section 20 and connector 30 each have lumens extending axially therethrough extending proximally and distally, the lumens of the main body section 10 communicating with the lumens of the thrombolytic section 20 and the connector 30. The connector 30 is adapted to be connected to a source of high pressure fluid (not shown) such that thrombolytic fluid from the source may pass through the connector 30, into the body segment 10 and the thrombolytic segment 20 in sequence, and finally out of the thrombolytic segment 20.

It will be appreciated that when the thrombolytic catheter 100 is used to treat a thrombotic problem in a patient's blood vessel, the thrombolytic catheter 100 may introduce the thrombolytic segment 20 through a guide into the patient's vascular thrombotic site. At this point, the body segment 10 is partially located in the patient's blood vessel, partially located outside the patient's body, and the connector 30 is located outside the patient's body. When the thrombolytic segment 20 of the thrombolytic catheter 100 is introduced into a thrombus site of a patient, a thrombolytic fluid for dissolving thrombus may be injected into the thrombolytic catheter 100 by a high pressure fluid source, and the thrombolytic fluid is ejected to the thrombus site through the thrombolytic segment 20 to dissolve and remove the thrombus.

The guide may be a guide wire, an attached medical device (e.g., a guide sheath), or the like.

In this embodiment, the distal end of the connector 30 is fixedly attached to the proximal end of the body segment 10. The proximal end of the connector 30 has an opening communicating with the lumen of the connector 30, and the proximal end of the connector 30 is connected to a source of high pressure fluid, which communicates with the opening of the connector 30, such that the source of high pressure fluid can inject thrombolytic fluid into the connector 30 through the opening. It will be appreciated that the lumen of the connector 30 forms a channel for thrombolytic fluid. Of course, in other embodiments, the distal end of the connector 30 may also be detachably connected to the proximal end of the body segment 10.

Illustratively, the proximal sidewall of the connector 30 is threaded to facilitate connection to a high pressure fluid source. Of course, in other embodiments, the proximal end of the connector 30 may not be threaded, and the connector 30 may be connected to a source of high pressure fluid by other means of connection, such as bonding, welding, etc.

In some embodiments, the middle side wall of the connecting piece 30 is further sleeved with a screwing piece 31, an operator can rotate the screwing piece 31 to drive the whole thrombolytic catheter 100 to axially move and circumferentially rotate, and the screwing piece 31 can be integrally made with the connecting piece 30 so as to enhance the connection strength between the two.

In this embodiment, the connector 30 is a luer fitting, which is a conventional design for those skilled in the art and will not be described in detail herein. Of course, in other embodiments, the connector 30 may be other connectors than luer connectors, so long as the connection of the body segment 10 to a source of high pressure fluid is accomplished.

In this embodiment, the high-pressure fluid source may be a syringe, a perfusion pump or other thrombolytic fluid source, and is used to inject high-pressure thrombolytic fluid into the thrombolytic catheter 100, where the impact pressure of the thrombolytic fluid in the high-pressure fluid source is between 200Pa and 600Pa, preferably 500Pa. It will be appreciated that the high pressure impact energy breaks the broken thrombus of the thrombolytic catheter 100 even further into smaller emboli, increasing the total area of thrombus fragments exposed to thrombolytic fluid, achieving both physical and chemical thrombolysis effects.

The thrombolytic liquid is a medicament with thrombolytic function, and further, the thrombolytic liquid can be mixed with contrast agent to realize contrast function at the same time. Common thrombolytic agents are recombinant urokinase, streptokinase, recombinant tissue fibrin, plasminogen activator, and the like. In this example, the thrombolytic agent is a mixture of reconstituted urokinase and a contrast agent. In other embodiments, the thrombolytic fluid may be only a drug having thrombolytic function.

In this embodiment, the main body section 10 is an elongated tubular flexible tube with a certain hardness, and may be made of a high polymer material, such as one or more of polyetheretherketone (poly ether ether ketone, PEEK), acrylonitrile butadiene styrene (Acrylonitrile Butadiene Styrene plastic, ABS), polyethylene (PE), polypropylene (PP), polyether block Polyamide (PEBAX), polycarbonate (PC), polyurethane (PU), nylon (Nylon), polyvinylchloride (Polyvinyl chloride, PVC), polytetrafluoroethylene (Poly tetra fluoroethylene, PTFE) or Polybutylene (PB), or a copolymer or a mixture of two or more of them, and may also be made of a biocompatible metal, such as nickel titanium alloy.

The body section 10 may be a single layer tube or a multi-layer tube, such as a multi-layer tube of flexible tubing formed by hot melt forming an inner layer, a middle layer, and an outer layer. The inner layer may be polytetrafluoroethylene PTFE, or high density polyethylene HDPE, or a block polyether amide elastomer Pebax containing a coefficient of friction reducing additive. The intermediate layer may be one or more sections of metal woven mesh or metal spring mesh to provide rigidity to provide support for the body section 10. The outer layer may be nylon or a segmented polyether amide elastomer Pebax or a polyester polyurethane to provide protection to the body segment 10.

In this embodiment, as shown in fig. 1, the axial length of the main body section 10 is between 500mm and 1000mm, preferably 800mm, the inner diameter of the inner cavity of the main body section 10 may be 0.5mm to 3mm, preferably 1.5mm, and the outer diameter of the main body section 10 is 1mm to 5mm, preferably 2mm. Of course, in other embodiments, the inner diameter of the lumen of the body segment 10 may vary from 0.5mm to 3mm, and the outer diameter of the body segment 10 may vary from 1mm to 5mm.

Referring to fig. 2, fig. 2 is a schematic view of a portion of the thrombolytic catheter shown in fig. 1.

In this embodiment, the proximal end of the thrombolytic segment 20 is connected to the distal end of the body segment 10 such that the lumen of the thrombolytic segment 20 communicates with the lumen of the body segment 10. The thrombolytic segment 20 is capable of switching between a straight state and a helical state, the thrombolytic segment 20 being of a substantially rectilinear configuration when the thrombolytic segment 20 is in the straight state. When the thrombolytic segment 20 is in a helical state, the thrombolytic segment 20 forms a helical structure, i.e. a spiral structure.

The side wall of the thrombolytic section 20 is provided with a first through hole group 21 and a second through hole group 22, the first through hole group 21 comprises a plurality of first through holes 211 communicated with the inner cavity of the thrombolytic section 20, and the second through hole group 22 comprises a plurality of second through holes 221 communicated with the inner cavity of the thrombolytic section 20. When the thrombolytic segment 20 is in a spiral state, the first through hole group 21 and the second through hole group 22 are respectively spirally distributed on the thrombolytic segment 20, and each first through hole 211 is provided with a second through hole 221 which is positioned on the same circumference and is radially opposite to the first through hole.

The thrombolytic segment 20 is in a natural state of the thrombolytic segment 20 when in a spiral state. Before introducing the thrombolytic segment 20 into the thrombus site 400 of the patient's vessel 200, as shown in fig. 3, a guide member such as a guide wire 300 may be inserted from the opening of the connector 30, sequentially penetrating the connector 30, the body segment 10 and the thrombolytic segment 20, and the thrombolytic segment 20 is switched from a spiral state to a straight state by the guide wire 300 due to the insertion of the guide wire 300 into the lumen of the thrombolytic segment 20, so that the thrombolytic segment 20 is introduced into the thrombus site 400 of the patient's vessel 200. After the thrombolytic segment 20 has been introduced into the thrombus site 400 of the patient's blood vessel 200, the guide wire 300 is withdrawn, and as shown in fig. 4, the thrombolytic segment 20 is restored from the straight state to the spiral state, thereby effectively increasing the administration range, increasing the contact area of the thrombolytic segment 20 and the thrombus, and achieving a better thrombolytic effect.

According to the invention, the first through hole group 21 and the second through hole group 22 are formed on the thrombolytic section 20, and when the thrombolytic section 20 is in a spiral state, the first through hole group 21 and the second through hole group 22 are respectively spirally distributed on the thrombolytic section 20, and each first through hole 211 is provided with a second through hole 221 which is positioned on the same circumference and is arranged in a radial opposite manner. That is, the plurality of first through holes 211 and second through holes 221 may be spirally distributed along the spiral structure, so that the spatial arrangement range of the first through holes 211 and the second through holes 221 is expanded, thereby expanding the acting direction of the thrombolytic liquid, so that the thrombolytic section 20 can spray the thrombolytic liquid toward the thrombus through the plurality of directions of the first through hole group 21 and the second through hole group 22 around the thrombolytic section 20, thereby effectively increasing the administration range, increasing the contact area of the thrombolytic section 20 and the thrombus, and further enhancing the thrombolytic effect. And the design of thrombolysis section 20 makes a plurality of through-holes that set up in thrombolysis section 20 have different thrombolysis liquid outflow directions, not only is limited to flowing out around the pipe diameter of approximately being the straight line type, increases thrombolysis liquid and thrombus's area of contact to improve operation thrombolysis effect, improve the operation success rate.

Referring to fig. 5, fig. 5 is a schematic view of the thrombolytic catheter shown in fig. 1 at another angle.

In this embodiment, the axial length D1 of the thrombolytic segment 20 in the spiral state may be in the range of 20mm to 30mm (where the axial length D1 refers to the length of the thrombolytic segment 20 in the spiral state along the direction of the spiral center line thereof), and the axial length of the thrombolytic segment 20 in the flat state may be in the range of 40mm to 120 mm. By limiting the axial length of the thrombolytic segment 20 in different states, a better thrombolytic effect of the thrombolytic segment 20 is ensured.

The outer diameter corresponding to the cross section of the spiral structure (the structure when the thrombolytic section 20 is in the spiral state) perpendicular to the central axis (the spiral central line) can be the same from the proximal end to the distal end, the outer diameter corresponding to the cross section of the spiral structure perpendicular to the central axis can be 10 mm-30 mm, and the outer diameter corresponding to the cross section where the lumen of the thrombolytic section 20 is located can be the same from the proximal end to the distal end and 0.5 mm-3 mm.

Of course, in other embodiments, the outer diameter of the spiral structure corresponding to a cross section perpendicular to its central axis may also vary from the proximal end to the distal end, and may vary from 10mm to 30 mm. The outer diameter of the cross section of the thrombolytic segment 20, which corresponds to the lumen, may also vary from the proximal end to the distal end, and may vary from 0.5mm to 3mm.

As shown in fig. 5 and 6, fig. 6 is a schematic view of the thrombolytic section of the thrombolytic catheter shown in fig. 5 at another angle. Wherein, the spiral structure and the thrombolytic section adopt the same reference numerals.

The spiral structure 20 may be three-dimensional spiral or planar spiral. In this embodiment, the spiral structure 20 is three-dimensional and spiral, and the spiral structure 20 is wound at least once. It will be appreciated that the thrombolytic section 20 is formed by a spiral structure 20, so that the thrombolytic section 20 enters the target site of the patient (the thrombus site of the blood vessel) to be fully contacted with the thrombus, and the spiral structure 20 has good bending property and high stability after molding.

The outer diameter of the helix 20 (here, the outer diameter refers to the outer diameter corresponding to the envelope formed around the circumference of the helix 20, i.e., the outer diameter corresponding to the cross-section of the helix 20 perpendicular to its helical centerline) may vary from proximal to distal, it being understood that the outer diameters of the plurality of helical turns increase gradually from the proximal end of the helix 20 to the distal end of the helix 20. The outer diameter of the helical structure 20 may vary from 10mm to 30 mm. Of course, in other embodiments, the outer diameter of the helical structure 20 may be the same from the proximal end to the distal end.

In some embodiments, the helical structure 20 is wound at least one revolution, that is, the helical structure 20 comprises at least one or more complete helical turns, or comprises one or more complete helical turns in combination with non-complete helical turns (e.g., 1.5 helical turns, 2.5 helical turns, etc.), wherein a complete helical turn means that the helical turn is circumferentially wound 360 ° and a non-complete helical turn means that the helical turn is circumferentially wound less than 360 °. The distance between every two adjacent turns of the spiral structure 20 may be in the range of 2 mm-4 mm, and the number of turns of the spiral structure 20 may be between 2 and 5.

In this embodiment, the helical centre line of the helical structure 20 coincides with the axis of the body segment 10 and with the helical centre line of each helical turn, so that the thrombolytic segment 20 is more convenient to introduce into the blood vessel. Of course, in other embodiments, the helical centerline of the helical structure 20 may also be parallel or at an angle to the axis of the body segment 10, and when the helical structure 20 has multiple helical turns, the helical centerline of each helical turn may be coincident, parallel or at an angle.

As shown in fig. 5, the spiral structure 20 includes a proximal spiral section 23 and a distal spiral section 24, the proximal spiral section 23 being connected between the main body section 10 and the distal spiral section 24, and a first through-hole group 21 and a second through-hole group 22 being formed on the distal spiral section 24. It will be appreciated that the first set of through holes 21 and the second set of through holes 22, by being formed on the distal helical section 24, provide a better thrombolysis effect than if they were formed on the proximal helical section 23 to be able to more fully contact the thrombus in the vessel.

Wherein, the outer diameter D3 of the distal spiral section 24 is larger than the outer diameter D2 of the proximal spiral section 23, the outer diameter D3 of the distal spiral section 24 refers to the outer diameter of the envelope formed by enveloping the outer periphery of the distal spiral section 24, and the outer diameter D2 of the proximal spiral section 23 refers to the outer diameter of the envelope formed by enveloping the outer periphery of the proximal spiral section 23. It will be appreciated that the proximal helical segment 23 is the initial segment of the helix 20, and that the design of the proximal helical segment 23 reduces the resistance to shaping of the distal helical segment 24 to better shape it, while also providing sufficient support for the distal helical segment 24 to make the helix 20 more stable.

Optionally, the value of D3 can be between 10mm and 30mm, and the value of D2 can be between 0.5mm and 5mm.

In some embodiments, the distal helical segment 24 comprises at least one complete helical turn, i.e., the distal helical segment 24 is wound at least one turn, i.e., the distal helical segment 24 is wound at an angle greater than or equal to 360 ° from proximal to distal in its axial direction, such that a 360 degree helical distribution within the vessel can be achieved, which can increase the extent of administration and thus increase the contact range of thrombolytic fluid with thrombus. By way of example, the distal helical segment 24 may comprise 1 to 3 helical turns, preferably 1, and the length of the distal helical segment 24 along the direction of the helical centre line may vary from 10mm to 25mm, preferably from 10mm to 15mm.

As shown in fig. 7, fig. 7 is a schematic view of the thrombolytic segment of the structure shown in fig. 5in a straight state.

When the thrombolytic segment 20 is in a flat state, the thrombolytic segment 20 is of a generally linear configuration. Projections of the first through holes 211 of the first through hole group 21 and the second through holes 221 of the second through hole group 22 on a reference plane perpendicular to the axis of the thrombolytic section 20 are located on the same circumference and uniformly distributed on the circumference, so that when the thrombolytic section 20 is of a spiral structure 20, the thrombolytic liquid injection direction of the thrombolytic section 20 is 360 degrees, thereby realizing 360-degree omnibearing injection and improving thrombolytic efficiency.

The generally linear structure includes a distal section 25 and a proximal section 26 for connecting the distal section 25 to the distal end of the body section 10. Wherein distal section 25 is configured to be wound to form distal helical section 24 (shown in fig. 5) and proximal section 26 is configured to be wound to form proximal helical section 23 (shown in fig. 5). In the present embodiment, the first and second sets of through

holes

21, 22 are provided in the distal section 25. The first set of through holes 21 may comprise 6 first through holes 211 and the second set of through holes 22 may comprise 6 second through holes 221, each first through hole 211 having one second through hole 221 located on the same circumference and disposed diametrically opposite along the distal section 25. In other embodiments, the number of the through-hole groups may be 1 group, 3 groups, 4 groups, 5 groups, or the like, and the number of each through-hole group including the through-holes may be 3, 7, 8, 9, or the like, and the embodiment of the present invention is not particularly limited with respect to the number of the through-hole groups and the number of the through-holes included in each through-hole group.

The first through hole group 21 and the second through hole group 22 are respectively spirally distributed on the outer peripheral surface of the distal section 25, and the axial distance between any two axially adjacent through holes in the first through hole group 21 and the second through hole group 22 is equal. Any corresponding central angles between two through holes adjacent in the circumferential direction are equal, and in this embodiment, the central angle may be specifically 30 °. It can be understood that the corresponding central angles between two adjacent through holes are equal, so that the same quantity of thrombolytic liquid contacted with each part of thrombus is ensured, the equilibrium of the release quantity of thrombolytic liquid at different positions is ensured, and the thrombolytic effect is further ensured. Of course, in other embodiments, when each through-hole group includes the number of through-holes being 3, the corresponding central angle between any two through-holes adjacent in the circumferential direction may be 60 °. In some implementations, when the thrombolytic segment 20 is of a generally linear configuration, the axial distance between the through-hole closest to the proximal end of the distal segment 25 and the through-hole closest to the distal end of the distal segment 25 is between 35mm and 95mm, approximately 60% -95% of the axial length of the distal segment 25, the axial distance from the through-hole closest to the proximal end of the distal segment 25 is between 1mm and 4mm, the axial distance from the through-hole closest to the distal end of the distal segment 25 is between 1mm and 4mm, and the axial spacing between any two axially adjacent through-holes is between 3mm and 15mm.

It will be appreciated that by providing two rows of through holes, two through holes are provided on the same circumference of the distal section 25, which are opposite to each other, the distal spiral section 24 can be kept to have thrombolytic fluid flowing out on opposite sides during thrombolytic surgery, thereby further increasing the range of flow of thrombolytic fluid, reducing the problem of insufficient coverage of thrombus by thrombolytic fluid, and improving thrombolytic efficiency.

In this embodiment, the number of through holes (the first through holes 211 and the second through holes 221) may be between 6 and 20, and the shape of the through holes may be one or a combination of several of a circle, an ellipse, a square, a diamond, a triangle, a polygon, a straight groove, an S-shaped curve, a keyhole groove, a comma-shaped opening, and a teardrop-shaped opening. The size and/or shape of the plurality of through holes can be the same or different, and the aperture of the through holes can be between 0.3mm and 2mm. Of course, in other embodiments, the proximal helical segment 23 may be provided with one or more through holes.

Further, the through holes (the first through hole 211 and the second through hole 221) may be cut by a laser cutting technique, and in this embodiment, the diameter of the through hole (the first through hole 211 or the second through hole 221) gradually increases from inside to outside along the thickness direction of the wall of the distal spiral section 24, so as to increase the injection range of the thrombolytic liquid and improve the thrombolytic efficiency. By way of example, the angle between the tangential plane (hole wall) of the through hole (the first through hole 211 or the second through hole 221) and the axis of the through hole is 20 ° to 60 °, preferably 45 °, so that the injection range of the thrombolytic liquid can be more effectively increased, and the thrombolytic efficiency can be improved.

Of course, in other embodiments, the cross-section of the through-hole may be at right angles to the axis of the through-hole or the diameter of the through-hole may decrease from the inside to the outside in the direction of the wall thickness of the distal helical segment 24.

In this embodiment, the thrombolytic segment 20 may be made of a high molecular polymer material, such as a copolymer or mixture of one or more of PEEK, ABS, PE, PP, PEBAX, PC, PU, nylon, PVC, PTFE or PB, or a shape memory metal/alloy or other heat-settable metal/alloy (e.g., nickel-titanium (Ni-Ti) alloy, nickel-titanium-cobalt alloy (Ni-Ti-Co), double layer composite wire (Ni-Ti@Pt), etc.). Of course, the thrombolytic segment 20 may be integrally formed with the main body segment 10, and the main body segment 10 may be heat-set to obtain a spiral shape.

In other embodiments, the pre-shaped thrombolytic segment 20 may be pre-shaped into a spiral curved shape and then fixedly connected with the distal end of the main body segment 10 by means of welding, fusing, bonding, sleeving, etc., or the non-pre-shaped thrombolytic segment 20 may be fixedly connected with the distal end of the main body segment 10 by means of welding, fusing, bonding, sleeving, etc., and then the non-pre-shaped thrombolytic segment 20 may be shaped into a spiral curved shape.

In further embodiments, a developing member may be provided at the distal end of the thrombolytic segment 20, or a developing material may be embedded at the distal end of the thrombolytic segment 20, the developing member or developing material being made of a non-X-ray transmissive metallic material, such as one or more of iron, copper, gold, platinum, titanium, nickel, iridium.

In a further embodiment, the distal end of the thrombolytic segment 20 may be designed as a rounded taper with an outer diameter that gradually decreases from the proximal end to the distal end, and the distal end of the thrombolytic segment 20 may be made of a softer metal material that reduces scraping of the inner wall of the vessel.

Further, referring to fig. 8, the cross-sectional area of the lumen of thrombolytic segment 20 decreases gradually from the proximal end to the distal end. That is, the thrombolytic segment 20 is configured to gradually decrease in cross-sectional area through the lumen of the thrombolytic fluid from the proximal end toward the distal end thereof. It can be appreciated that, since the thrombolytic segment 20 is provided with a plurality of through holes (the first through hole 211 and the second through hole 221) along the length direction, the pressure of the thrombolytic liquid (fluid) in the cavity of the thrombolytic segment 20 from the proximal end to the distal end is gradually reduced, which causes uneven distribution of the thrombolytic liquid along the length direction of the thrombolytic segment 20 and also easily causes insufficient injection pressure of the thrombolytic liquid at the distal portion, thereby affecting the thrombolytic effect. The cross-sectional area of the inner cavity of the thrombolytic section 20 is gradually reduced from the proximal end to the distal end, so that the thrombolytic resistance of the thrombolytic liquid gradually increases from the proximal end to the distal end along the thrombolytic section 20, and further, each region in the axial direction of the thrombolytic section 20 is ensured to have enough pressure so that the thrombolytic liquid can be sprayed onto the thrombus through the through hole.

Meanwhile, when the distal end of the thrombolytic section 20 is provided with an opening (the distal end opening of the thrombolytic section 20 is designed through a guide wire), the distal end opening greatly reduces the pressure of the thrombolytic liquid at the distal part of the thrombolytic section 20, so that the influence of the distal end opening on the pressure of the thrombolytic liquid at the distal part of the thrombolytic section 20 is greatly neutralized by the change of the cross-sectional area, and the sufficient pressure in each region of the thrombolytic section 20 in the axial direction is further ensured, so that the thrombolytic liquid can be sprayed onto the thrombus through the through holes, the suitability of the thrombolytic catheter 100 to different application scenes is improved, and meanwhile, the thrombolytic catheter has a simple structure and is easy to process.

Of course, in other embodiments, it is also possible that only the cross-sectional area of the lumen of distal segment 25 or distal helical segment 24 gradually decreases from proximal end to distal end, and the cross-sectional area of the lumen of proximal segment 26 or proximal helical segment 23 remains unchanged from proximal end to distal end.

Further, the ratio of the cross-sectional area of the distal end of the thrombolytic segment 20 to the cross-sectional area of the proximal end of the thrombolytic segment 20 is between 0.4 and 0.8, preferably 0.5. The inner diameter of the thrombolytic section 20 corresponding to the cross-sectional area of the distal end of the thrombolytic section 20 is between 0.4mm and 2.4mm, the inner diameter of the thrombolytic section 20 corresponding to the cross-sectional area of the proximal end of the thrombolytic section 20 is between 1mm and 3mm, and the thrombolytic section 20 can pass through the guide wire and simultaneously further ensures that each area in the axial direction of the thrombolytic section 20 has enough pressure so that thrombolytic liquid can be sprayed onto thrombus through the through holes.

The following describes the use of the thrombolytic catheter 100 according to the present invention in a surgical procedure, taking the thrombolytic catheter 100 according to the present invention as an example for treating pulmonary arterial thrombosis.

There are a variety of routes for the surgical procedure, for example, the thrombolytic catheter 100 may be used to remove thrombi from the pulmonary artery via the femoral vein-inferior vena cava-right atrium-right ventricle-pulmonary artery interventional route.

Step one: referring to fig. 3, a thrombolytic catheter 100 is delivered to a target site within a pulmonary artery by an Over The Wire (OTW) technique. Specifically, the guidewire 300 is passed through the renal artery to the pulmonary artery, and then the distal opening of the thrombolytic catheter 100 is threaded over the guidewire 300, and the thrombolytic catheter 100 is advanced along the path established by the guidewire 300 to the pulmonary artery in an approximately straight delivery state.

Step two: referring to fig. 4, the guidewire 300 is withdrawn from the lumen of the thrombolytic catheter 100 and the thrombolytic catheter 100 returns to its natural shape, i.e., the thrombolytic section 20 of the thrombolytic catheter 100 transitions from a straight state to a coiled state, forming a coiled structure 20. It should be appreciated that the thrombolytic segment 20 may also be transitioned between a straightened state and a coiled state using a variety of other suitable mechanisms or techniques, and that the distal end of the thrombolytic segment 20 may be configured to be occluded in this use scenario if the thrombolytic catheter 100 is delivered to the target site via an introducer sheath.

Step three: the proximal end of the thrombolytic catheter 100 is connected to a high-pressure fluid source, and high-pressure thrombolytic fluid enters the lumen of the thrombolytic section 20 through the lumen of the main body section 10 and is sprayed out from a plurality of through holes (a first through hole 211 and a second through hole 221) of the thrombolytic section 20, thereby realizing the actions of thrombolysis and thrombolysis, in the process, an operator can advance, retreat, twist, rotate, slide, move and swing the thrombolytic catheter 100, and the operator can repeat the operation steps three 2 to 3 times as required, so that most of thrombus is fully disintegrated. In addition, the high pressure can cause the fragmented emboli to migrate further toward the distal end of the pulmonary artery, into the trunk of the pulmonary artery, thereby relieving pulmonary arterial pressure.

The foregoing disclosure is illustrative of the preferred embodiments of the present invention, and is not to be construed as limiting the scope of the invention, as it is understood by those skilled in the art that all or part of the above-described embodiments may be practiced with equivalents thereof, which fall within the scope of the invention as defined by the appended claims.

Claims

1. A thrombolytic catheter, said thrombolytic catheter comprising:

a body segment having a lumen extending axially therethrough and extending through proximal and distal ends thereof; and

A thrombolysis section connected to the distal end of the main body section, the lumen of the thrombolysis section communicating with the lumen of the main body section; the thrombolysis section can be switched between a straight state and a spiral state, when the thrombolysis section is in the spiral state, the thrombolysis section forms a spiral structure, and the spiral center line of the spiral structure is coincident with or parallel to the axis of the main body section;

a first through hole group and a second through hole group are formed in the side wall of the thrombolytic section, the first through hole group comprises a plurality of first through holes communicated with the inner cavity of the thrombolytic section, and the second through hole group comprises a plurality of second through holes communicated with the inner cavity of the thrombolytic section;

when the thrombolytic section is in a spiral state, the first through hole group and the second through hole group are respectively spirally distributed on the thrombolytic section, and each first through hole is provided with a second through hole which is positioned on the same circumference and is arranged in a radial opposite way.

2. The thrombolytic catheter of claim 1, wherein projections of said first plurality of through holes and said second plurality of through holes on a reference plane perpendicular to an axis of said thrombolytic segment are located on a same circumference and uniformly distributed on the circumference when said thrombolytic segment is in a straight state.

3. The thrombolytic catheter of claim 1, wherein said spiral structure comprises a plurality of spiral turns having an outer diameter that increases gradually from a proximal end of said spiral structure to a distal end of said spiral structure.

4. A thrombolytic catheter as claimed in claim 1 or 3 wherein said spiral structure comprises a proximal spiral section and a distal spiral section, said proximal spiral section being connected between said main body section and said distal spiral section, said first set of through holes and said second set of through holes being formed on said distal spiral section.

5. The thrombolytic catheter of claim 4, wherein said distal helical segment is wrapped at least one turn.

6. The thrombolytic catheter of claim 4, wherein the diameter of said first through hole increases gradually from inside to outside along the wall thickness of the distal spiral segment.

7. The thrombolytic catheter of claim 6, wherein an angle between a wall of said first through hole and an axis of said first through hole is 20 ° to 60 °.

8. The thrombolytic catheter of any one of claims 1-7, wherein the cross-sectional area of the lumen of said thrombolytic segment decreases from the proximal end to the distal end.

9. The thrombolytic catheter of claim 8, wherein the ratio of the cross-sectional area of the distal end of said thrombolytic segment to the cross-sectional area of the proximal end of said thrombolytic segment is between 0.4 and 0.8.

10. The thrombolytic catheter of claim 1, wherein the distal end of said thrombolytic section is smoothly transitioned conical.

11. The thrombolytic catheter of claim 1, wherein a distal end of said thrombolytic segment is provided with a developing member or embedded with a developing material.

12. The thrombolytic catheter of claim 1, further comprising a connector attached to an end of said main body section remote from said thrombolytic section, said connector for connection to a source of high pressure fluid.