WO2023092200A1

WO2023092200A1 - Endovascular device for capturing and removing thrombi

Info

Publication number: WO2023092200A1
Application number: PCT/BR2021/050573
Authority: WO
Inventors: George NEVES DE ALMEIDA
Original assignee: Neves De Almeida George
Priority date: 2021-11-24
Filing date: 2021-12-22
Publication date: 2023-06-01

Abstract

The present invention patent pertains to the field of health care and consists in a device for removing thrombi (blood clots) from the pulmonary artery of adult humans, comprising a catheter with three lumens, on which a semi-compliant ring-shaped balloon is mounted and inflated from its collapsed shape with a saline solution injected through two of the catheter lumens, the balloon catheter having attached to the outer edge thereof the mouth of a conical bag made of a blood-permeable but thrombi-impermeable mesh that forms together with the ring-shaped balloon a windsock-like object with the function of capturing the thrombi, and three wires that keep the ring-shaped balloon attached to the catheter and serve to pull and collect the ring-shaped balloon inside a hem, after the thrombi have been captured.

Description

"ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS"

[01] The present invention patent is part of the health area and consists of a device for removing thrombi (blood clots) from within the pulmonary artery of adult humans, consisting of a catheter with three lumens, on which a balloon is mounted semi-compliant ring-shaped balloon, called a ring-balloon, which is expanded from its collapsed form by being inflated with saline solution, injected through two of the catheter lumens, a ring-balloon that has a mouth attached to its outer edge of a conical mesh bag, porous to blood but impermeable to thrombi, composing together with the balloon-ring an object similar to a windsock, whose function is to capture the thrombi, and three threads that keep the balloon-ring attached to the catheter and serve as a means to pull and collect the balloon-ring into a sheath after capturing the thrombi.

[02] Pulmonary embolism is the obstruction of the pulmonary artery and/or its branches by clots brought by venous blood flow, usually originating in veins of the lower limbs. The trunk of the pulmonary artery is the outflow tract of the right ventricle of the heart and divides into the right and left pulmonary arteries, which go to the respective lungs. Massive and submassive pulmonary embolism is a serious disease, with high morbidity and mortality, characterized by obstruction of the pulmonary arteries and/or their main branches by large masses of thrombi, being one of the main causes of in-hospital death. A device that can quickly and minimally invasively remove most of the thrombi could be very useful for the treatment of massive and submassive pulmonary embolism.

[03] In the current state of the art, thromboembolism of the pulmonary artery can be treated through surgical opening of this artery, or through endovascular percutaneous thrombectomy devices, or through systemic drug thrombolysis. [04] In the first method, a surgical opening of the thorax is performed, opening the pulmonary artery and extracting the thrombi inside it. This method is not usually used because it is a major surgery, with high patient morbidity and mortality.

[05] In the second method, a catheter is introduced through the femoral vein, through percutaneous puncture and progressed through the vascular system, passing through the right heart chambers, until reaching the pulmonary artery, under real-time visualization in a radioscopy device (hemodynamics). ). Once the catheter reaches the pulmonary artery, a thrombectomy device is taken through the same route to the pulmonary artery and used for fragmentation and/or aspiration of thrombi, such as those described below.

[06] The Indigo-Penumbra device is a catheter that aspirates clots inside the vessel through negative pressure, with the aid of a mobile ogive at the end of the catheter, used to fragment the thrombus into smaller pieces. Aspiration time may be limited by the volume of blood removed along with the thrombi. Its angled tip allows for some maneuverability and amplitude, but with a limited range of action within the lumen of a large vessel such as the pulmonary artery. This device obtained good clinical results in the treatment of severe pulmonary thromboembolism, by partially removing the thrombi from the pulmonary artery, with improved lung perfusion and reduced overload on the right heart (Indigo Aspiration System for Treatment of Pulmonary Embolism: Results of the EXTRACT- PE Trial). This device differs from the object of this patent application as it is a thrombus aspiration catheter.

[07] The Flowtriever device consists of an aspiration catheter and a metallic mesh. Aspiration is done through suction through a syringe, always bringing some volume of blood with it. The capture of thrombi is done by expanding the metal mesh through the thrombi, which causes shearing of the thrombi and their penetration and apprehension in the metal mesh. The mesh is then collected to inside the catheter, bringing with it the thrombi. Part of the thrombi may remain in the lumen and possibly some fragments may embolize to distal branches of the pulmonary artery, which is undesirable. This device has also achieved good clinical results in the treatment of severe pulmonary thromboembolism (A Prospective, Single-Arm, Multicenter Trial of Catheter-Directed Mechanical Thrombectomy for Intermediate-Risk Acute Pulmonary Embolism: The FLARE Study). This device differs from the object of this patent application because it is a system that depends on the shearing and seizure of thrombi by the metal mesh, associated with a thrombus aspiration catheter.

[08] The Aspirex device fragments and aspirates thrombi through a catheter that contains a helical system inside, rotating at high speed. The aspiration time is limited by the volume of blood removed together with the thrombi. Its tip is straight, non-steering, which limits its range of action within the lumen of a large vessel such as the pulmonary artery. This device has not been recommended for the treatment of pulmonary thromboembolism by the main scientific publications on the subject. This device differs from the object of this patent application as it is a thrombus aspiration catheter.

[09] The Angiojet device is a catheter that uses a jet of saline and the venturi phenomenon to break up and aspirate clots. Its wearing time is limited by device-induced hemolysis. Fragmentation of thrombi possibly causes embolization to distal branches of the pulmonary artery, which is undesirable. The catheter has a straight, non-steerable tip, which limits its range of action within the lumen of a large vessel such as the pulmonary artery. This device has not been recommended for the treatment of pulmonary thromboembolism by the main scientific publications on the subject. This device differs from the object of this patent application as it is a thrombus fragmentation and aspiration system. [010] BR 1 12013029184-2 "Thrombectomy device" refers to a thrombectomy device, with a stent structure, essentially cylindrical, which has a variety of meshes, as well as two connectors, arranged in different meshes at the end proximal part of the stent structure, presenting a conductive wire, which has a coupler element, to which the connectors are attached, as well as a slit, which extends in a spiral shape on the lateral face of the stent structure, and with a handle tensioner that covers the crack at the proximal end.This device differs from the object of the present patent application because it depends on the shearing and adhesion of the thrombi to the metal mesh for its removal.

[01 1] BR1 12017015037-9 "Thrombectomy device and system for extracting vascular thrombi from a blood vessel" comprises a delivery catheter, a dilator catheter and a funnel, which defines a distal end and a proximal end, in which said funnel is positionable in a retracted position and in an extended position, and is characterized in that said funnel also comprises a cover, wherein the diameter of the distal end of the funnel is greater in the extended position than in the retracted position. This allows aspiration from a location very close to the thrombus and with a large mouth, allowing occlusion of the artery, stopping the flow and aspirating the entire thrombus without fragmenting it. This device differs from the object of this patent application as it is a thrombus aspiration catheter.

[012] BR 1 12018010607-0 "clot removal device for removing occlusive clot from a blood vessel" refers to device for removing the clot from a body vessel and comprises an expandable structure and an elongated element. The expandable structure has a constrained release configuration, an expanded clot engaging configuration, and an at least partially constrained clot clamping configuration. At least a portion of the expandable structure is configured to engage the clot in the deployed expanded configuration and to arrest the moving clot from the deployed configuration to the clot capture configuration. The expandable structure may comprise a main body portion and a clot clamping structure wherein a diameter of the clot clamping structure is less than a diameter of the main body portion. The clot clamping structure in some cases is substantially tubular and may be spiral in shape. This device differs from the object of the present patent application because it depends on the shearing and adhesion of the thrombi to the metal mesh for its removal.

[013] BR 1 12021007203-9 "Device, apparatus for thrombectomy and system for automated maneuvering of the apparatus for thrombectomy" refers to a device, apparatus for thrombectomy and a method for extracting a thrombus from a blood vessel. The device comprises a segment that changes shape from a retracted position, in a compressed state, to an extended and expanded position. The segment is formed by a mesh of at least two sets of intertwined helical filaments running in opposite directions. The mesh comprises two distinct tubular sections. The mesh of the first section has helical filaments having a braiding angle that provides greater radial forces than the forces in the second section, and thus the first section is positioned against the inner wall of the blood vessel. The second section comprises two subsections. The first subsection is conical in shape and comprises a braiding angle that changes at its proximal and distal ends to provide a radial force to maintain the conical shape and to stop proximal blood flow during thrombus removal. This device differs from the object of the present patent application because it depends on the shearing and adhesion of the thrombi to the metal mesh for its removal. [014] In the third method of treating pulmonary artery thromboembolism, a medication that has the property of dissolving thrombi, commonly Alteplase, is administered in high doses into the bloodstream, through a peripheral vein, so that it exerts its action when passing thrombi in the pulmonary artery. Although complete thrombus dissolution does not occur, the clinical result with reduced mortality is superior to treatment with thrombolytics when compared to endovascular thrombectomy methods, according to the main scientific works on the subject. However, thrombolytics act indistinctly on large and small thrombi, located anywhere in the body and, therefore, pose a risk of serious or fatal bleeding complications to patients who have recently undergone surgical interventions, with recent bleeding, victims of major trauma or accidents. recent stroke. About 30% to 40% of patients with severe pulmonary thromboembolism have some contraindication for the use of thrombolytics and, therefore, are candidates for treatment with an endovascular thrombectomy device.

[015] The object of this patent application has the following advantages: [016] It is for percutaneous, endovascular use, without the need for major surgery;

[017] It does not depend on the fragmentation of the thrombi to clear the vessel; [018] It does not depend on the aspiration of thrombi to clear the vessel;

[019] It does not depend on the interruption of blood circulation;

[020] It is possibly capable of removing a large mass of thrombi in a single, rapid passage of the device through the obstructed vascular segment;

[021] It is simple to use, based on inflation and deflation of the balloon, in addition to navigation and catheterization, techniques known by physicians who work with angioradiology and endovascular surgery; [022] This device can be better understood through the attached figure:

[023] Figure 1 illustrates a perspective view of the catheter, the inflated balloon-ring, the open bag, the three extended wires and free ends of the injection lumens; [024] Description of the invention:

[025] The object of this patent application is composed of a catheter (1), a balloon-ring (2), a bag (3) and three wires (4) and ends of injection lumens (5), described below follow.

[026] The catheter (1) is made of plastic material, such as nylon, polyethylene or polyurethane, with one end called the tip of the catheter and the other end called the bottom of the catheter, the bottom being that end that remains outside the patient's body, under control of the physician operating the device. The catheter (1) contains three distinct lumens (5), parallel to each other, one of them, called the main lumen (5), arranged longitudinally along the entire length of approximately 100 cm of the catheter (1), whose purpose is to allow passage to a guide wire with a thickness of 0.035 inches, and the other two lumens, called injection lumens, with an approximate extension of 80 cm from the bottom of the catheter (1 ), and, at the end of this extension, each of the injection lumens it ends at an end detached from the main body of the catheter (1), free and flexible, approximately 8 mm long, through which the saline solution leaves the injection lumen to fill the balloon (2), described below. The bottom of the catheter (1 ) continues with a tube made of rigid plastic material, with a Y division, in one of which the main lumen of the catheter opens (1 ) and in the other the injection lumens open together, and the Y division through which the guide wire passes has a straight position in relation to the catheter body (1 ).

[027] The balloon-ring (2) is made of plastic material, such as nylon, polyethylene or polyurethane, semi-compliant, with a cylindrical body of approximately 3 mm in diameter. This cylinder is shaped like an arc of a circle, with a diameter of approx. of 40 mm and approximate extension of 358 ^s of the circumference, and the plastic tissue of each of the ends of the arch ends overlapping each of the free ends of the catheter injection lumens (1) described above, through which the balloon (2) it can be inflated with saline solution, which promotes its expansion into a ring shape, which is why it is called a ring balloon (2).

[028] The device also has a bag (3) with an approximately conical shape, composed of a malleable fabric mesh, highly porous to blood and impermeable to clots, with a length of approximately 80 mm, whose bottom is closed and fixed near the tip of the catheter (1) and whose mouth is fixed along the most external edge of the balloon-ring (2), so that the expansion of the balloon-ring (2) causes the opening of the mouth of the bag (3), together composing a structure similar to a windsock and so that any content that passes through the inner circle delimited by the balloon-ring (2) enters the bag (3).

[029] Three nylon threads, thin and flexible, each approximately 6 cm long, have one of their ends attached to the mouth of the bag, at common points with the attachment of the bag to the balloon-ring, at points equidistant from each other and in relation to the catheter (1 ). The other ends of each wire are attached to a common point on the catheter, in the opposite position of the bag in relation to the balloon-ring. When the balloon (2) is inflated until it assumes its ring shape, the wires (4) are extended, assuming a shape similar to a tripod, and, when the catheter (1) is pulled, the wires (4) simultaneously pull the mouth of the bag (3) and the balloon-ring (2).

[030] This set of six parts of the device (catheter, three wires, balloon-ring and bag) has an active position of use when the balloon-ring is expanded by the injection of saline solution, using a syringe attached to the bottom of the catheter . The expansion of the balloon-ring causes the mouth of the bag to open and the threads to stretch. In its resting form, the balloon-ring, the bag and the three wires are completely collapsed, folded and juxtaposed to the catheter, so that the The set maintains an approximately cylindrical shape around the catheter and occupies minimal space, and can be easily advanced inside a sheath with an approximate caliber of 9F.

[031] So that the operating physician can visualize the position of the set within the vessel, there is a small tungsten radiopaque marker at the point where the wires are attached to the catheter, another on the catheter at the level of the free ends of the saline injection lumens, and another on the point of attachment of the bag to the catheter and, so that the balloon can be seen during its inflation and deflation, an injection of iodinated contrast mixed with saline solution is performed.

[032] To use the device, a 0.035-inch guidewire and a long sheath, approximately 8 F in caliber, are positioned inside the pulmonary artery. The device is then advanced within the sheath, and its tip is positioned within one of the branches of the pulmonary artery, beyond the site obstructed by thrombi. [033] In this position, the ring balloon is partially inflated under low pressure and the catheter is slowly pulled back, which should bring thrombi from the arterial branch into the main pulmonary artery. When the central mark of the catheter reaches the lumen of the main trunk of the pulmonary artery, the physician inflates the balloon-ring until its complete expansion, which should promote contact between the outer circumference of the balloon-ring and the inner circumference of the pulmonary artery, and , then, slowly pulls the catheter, causing the balloon-ring to be dragged along the obstructed pulmonary artery, which should force all the contents of the artery (blood and thrombi) to pass through the central circle delimited by the balloon-ring towards the bag, thus promoting the capture of thrombi inside the bag, contributing to this the flow of blood pumped by the right ventricle, pushing the contents of the vessel towards the bag. During this movement, it is expected that the three threads pulling the balloon-ring cross the thrombus mass, which is a soft material that is easily sheared by the threads brought under tension. [034] After dragging the balloon-ring along the entire length of the pulmonary artery obstructed by thrombi, the operator observes the position of the radiopaque marks and makes injections of contrast through the sheath to check the position of the thrombi inside the bag and then slowly empties the balloon-ring while pulling the wires into the sheath, which should cause reduction of the balloon-ring and closure of the mouth of the bag, with consequent trapping of the thrombi.

[035] With the thrombi trapped in the bag, the entire set can be removed from the pulmonary artery, which should promote clinical improvement for the patient. The thrombi trapped in the bag can then be brought up to the femoral vein and then removed through a small surgical opening of the vein or through aspiration of the bag, after which the device can be used again, if necessary.

Claims

CLAIM

1- “ENDOVASCULAR THROMBECTOMY DEVICE”, characterized by a catheter (1), a balloon (2), a bag (3) and three wires (4) and injection lumens (5).

2. "ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS", according to claim 1, characterized by a catheter (1) made of plastic material, such as nylon, polyethylene or polyurethane, with one end said catheter tip (1) and the other called bottom end of the catheter (1), the bottom being the end that remains outside the patient's body, under the control of the physician who operates the device, the catheter (1) containing three distinct lumens (5), arranged parallel to each other, one of them, said main lumen (5), disposed longitudinally along the entire length of approximately 100 cm of the catheter (1), whose purpose is to allow passage to a 0.035-inch-thick lead wire, and the other two lumens, said lumens of injection, with an extension of approximately 80 cm from the bottom of the catheter (1 ), and, at the end of this extension, each of the injection lumens ends in an end of approximately 8 mm in length, free and flexible, detached from the body main catheter (1), through which the saline solution leaves the injection lumen to fill the ring-balloon (2);

3. "ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS", according to claims 1 and 2, characterized by a balloon (2) made of plastic material, such as nylon, polyethylene or polyurethane, semi-compliant, with a cylindrical body of approximately 3 mm in diameter, a cylinder that forms an arc of a circle with an approximate diameter of 40 mm and an approximate length of ^358º of the circumference, with the plastic fabric at each end of the arc of circle ending up overlapping each of the free ends of the catheter injection lumens (1) described in claim 2, through which the balloon (2) can be inflated with saline solution, which promotes its expansion into a ring shape, therefore called a ring-balloon (2), the starting from a form of rest, folded, collapsed and juxtaposed to the catheter (1);

4. "ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS", according to claims 1 to 3, characterized by a bag (3) with a conical shape, composed of malleable fabric mesh, highly porous to blood and impermeable to clots, with approximately 80 mm in length, whose bottom is closed and fixed close to the tip of the catheter (1) and whose mouth is fixed along the most external edge of the balloon-ring (2), so that the expansion of the balloon-ring (2 ) causes the mouth of the bag (3) to open, forming a structure similar to a windsock and so that any content that passes through the inner circle delimited by the balloon-ring (2) enters the bag (3).

5. "ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS ^" ; according to claims 1 to 4 characterized by three thin and flexible nylon threads (4), each approximately 6 cm long, each thread (4) with one of its ends attached to the mouth of the bag (3), at common points with the attachment of the bag (3) to the balloon-ring (2), at points equidistant from each other and in relation to the catheter (1), and the other ends of each wire (4) fixed to a common point of the catheter (1), in the opposite position to the bag (3) in relation to the balloon-ring (2), so that, when the balloon-ring (2) is inflated, the wires (4) are extended, assuming a shape similar to a tripod, and, when the catheter (1) is pulled, the wires (4) simultaneously pull the mouth of the bag (3) and the balloon-ring (2 ).

6. "ENDOVASCULAR DEVICE FOR CATCHING AND REMOVING THROMBS according to claims 1 to 5, characterized by a set consisting of a balloon-ring (2), bag (3) and three wires (4), which are kept in the resting position folded, completely collapsed and juxtaposed to the catheter (1 ), so as to occupy a minimum space and maintain an approximately cylindrical shape around the catheter (1 ), which allows the insertion of the set into a sheath of approximately 9F, through which the device is taken to the vessel to be treated, where the set can then be expanded to a position of use, by inflating the balloon-ring (2) with saline solution, which promotes, simultaneously, the opening of the mouth of the bag (3) and the stretching of the threads (4), elements that, after capturing the thrombi, can be collected by deflating the balloon, achieved by aspiration of the saline solution, which simultaneously promotes the closure of the mouth of the bag (3) and the relaxation and approximation of the wires (4) of the catheter (1), allowing the traction of the catheter (1), the three wires (4), the balloon-ring (2) and the mouth of the bag (3) into the sheath, in order to keep the mouth of the bag closed (3) and seize the thrombi captured, finally allowing the device to be removed from the pulmonary artery, bringing the thrombi with it.