A delivery system for an implantable medical device

Abstract

The present invention discloses a delivery system for an interventional medical device, the delivery system is composed of an inner tube, an intermediate tube, a delivery sheath, a delivery sheath handle, and an operating handle, the delivery sheath is connected to the delivery sheath handle, the operating handle is connected to the inner tube and the intermediate tube, and the inner tube, the intermediate tube and the delivery sheath are used coaxially. The delivery system of the interventional device provided by the present invention can be adapted to grasping instruments such as peripheral arterial and venous thrombectomy stents and stone removal baskets, so that the instrument can reach most peripheral blood vessels, bronchial tubes and other human cavity parts, and adapt to the substantial changes in channel diameter during the grasping / releasing process, ensuring that the instrument can be attached to the wall in real time during grasping / releasing; greatly simplifying the operational difficulty of the interventional device for treating embolism and stenosis diseases in blood vessels, natural cavities, etc.; greatly reducing the risks introduced by the instrument itself such as damaging the inner wall of the blood vessel, and eliminating the risk of emboli escape during surgery.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and relates to a delivery system for delivery media and implanted devices, and in particular to a delivery system suitable for natural cavities of the human body with large changes in intracavitary cross-sectional areas, such as peripheral arteries, veins, and bronchial thrombectomy stents. Background Art

[0002] Acute limb ischemia is a rapid decrease in limb perfusion, usually causing new or worsening symptoms or signs, often threatening limb viability. Acute lower limb ischemia is mostly related to arterial occlusion, but extensive venous occlusion can also cause limb ischemia (i.e., phlegmasia femoris), but this situation is rare. The annual incidence of acute lower limb ischemia caused by acute peripheral arterial occlusion is about 1.5 cases per 10,000 people. The clinical manifestations depend on the cause and whether the patient has underlying peripheral artery disease (PAD). For many years, the main treatment has been surgical or catheter-based embolectomy and bypass grafting. Later, thrombolytic therapy and percutaneous transluminalangioplasty (PTA) became the treatment of choice for some patients. Venous thromboembolism (VTE) refers to a type of disease in which blood clots cause obstruction of blood flow in the venous system, and the triggering factors include damage to the vein wall, abnormal venous blood flow, and changes in blood composition. The symptoms of venous thromboembolism are not obvious in the early stage, and the naked eye cannot directly identify the diagnosis. If screening is neglected, it often leads to deep vein thrombosis or even pulmonary embolism. Similar to peripheral arterial thrombosis, the treatment of venous thrombosis is mainly thrombolysis and surgical / catheter thrombectomy.

[0003] Currently, there are an endless stream of interventional and implantable devices for neurovascular, peripheral vascular, and cardiovascular embolic / stenotic diseases. Although transcatheter thrombectomy has been widely used in clinical practice, and interventional thrombectomy based on various mechanisms such as fluid mechanics, stent scraping, and negative pressure aspiration has also shown a high success rate, there is still a relative lack of matching delivery systems. While various stents, thrombectomy stents, and balloons meet the growing clinical needs, they also expose some problems. For example, the design of the device mainly focuses on the accessibility of tortuous blood vessels, while relatively ignoring the difference in the distal and proximal diameters of long blood vessels, which often poses a problem for the selection of device specifications. Take iliac vein thrombosis as an example. The thrombus in this disease is often quite long, and may even extend from the popliteal vein to the inferior vena cava. The diameter of the entire involved area spans a large range (from about 6mm to about 30mm). The small-sized thrombectomy stent cannot remain attached to the wall throughout the thrombectomy path, resulting in incomplete thrombectomy. The residual thrombus is stimulated and even has the risk of falling off. Since the venous return blood enters the heart and is directly pumped into the pulmonary artery, the escape of the thrombus can easily cause pulmonary embolism; the large-sized thrombectomy stent will cause excessive radial support force in small-diameter blood vessels, damaging the inner wall of the blood vessel during the process of scraping the thrombus. For another example, due to the inherent rigidity and braiding characteristics of the thrombectomy stent itself, once the braided wire is knotted and stuck in the body, the remedy that can be performed outside the body is very limited. At this time, if the device is forcibly retrieved, it will cause damage to the inner wall of the cavity. Doctors often need to cut open the blood vessels (or other human cavities) to remove the deformed device, causing unnecessary harm to the patient.

[0004] Therefore, the present invention proposes a set of intravascular delivery systems adapted to peripheral blood vessels and natural cavities of the human body for operating thrombectomy stents, so as to solve the problems of poor thrombectomy effect, poor stent real-time wall adhesion performance, and high risk of thrombus escape caused by tortuosity of some blood vessels / cavities and large changes in the diameter of the thrombectomy passage during long-distance thrombectomy. At the same time, the thrombectomy operation is simplified. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a delivery system for an implantable device (hereinafter referred to as the delivery system), which is suitable for intracavitary thrombectomy in peripheral arteries, veins, bronchi, digestive tract, etc. The thrombectomy stent delivery system can deliver the thrombectomy stent to most peripheral blood vessels or other anatomical positions of natural cavities of the human body, so that the stent can smoothly grasp the thrombus and withdraw it from the human body in the best working state, solving the problem of poor thrombectomy effect caused by the tortuosity of some blood vessels / cavities and excessive changes in the lumen diameter of the thrombectomy passage. At the same time, it has a dual diameter adjustment function, which can take into account the needs of both the cavity diameter adaptive rapid thrombectomy and the manual adjustment of thrombectomy modes, effectively avoiding the risk of kinking and jamming of the thrombectomy stent. In addition, the device is simple to operate, easy for doctors to learn, and can reduce the risk of misoperation.

[0006] In order to achieve the above-mentioned purpose, the present invention proposes a delivery system for an implantable device. The delivery system adopts a three-layer catheter combination, which includes an inner tube, an intermediate tube, and a delivery sheath. The distal end of the inner tube is fixed to the distal end of the thrombectomy stent, and the distal end of the intermediate tube is fixed to the proximal end of the thrombectomy stent. The compression and release of the stent are achieved by the relative sliding of the inner tube and the intermediate tube. The intermediate tube has flexible bending performance and can adapt to the physiological curvature of most peripheral blood vessels or other natural cavities of the human body; the inner tube and the limiting component cooperate with the adjusting component to achieve real-time adjustment of the stent shape. The delivery sheath is used to accommodate the stent in a compressed state and deliver the stent to the target position.

[0007] Furthermore, the positioning component includes a limiting ring, which is fixed to the outer surface of the proximal end of the inner tube and is located inside the operating handle; the limiting ring can be made of elastic materials such as silicone, pebax, etc., or can be made of hard materials such as steel pipes; the limiting ring is a part of the positioning component, and cooperates with other positioning components to control the shape of the thrombectomy bracket.

[0008] Furthermore, the positioning component includes a diameter limiting ring, which is fixed to the outer surface of the distal end of the inner tube and is located in the inner cavity of the thrombectomy bracket; the diameter limiting ring can be made of elastic materials such as silicone, pebax, etc., and can also be made of hard materials such as steel pipes; the diameter limiting ring is a part of the positioning component, and cooperates with other positioning components to control the shape of the thrombectomy bracket.

[0009] Furthermore, the intermediate tube is fixed to an operating handle, and the axial movement of the intermediate tube can be controlled by pulling the operating handle.

[0010] Furthermore, the intermediate tube has a first identification element at the distal end, and the first identification element is made of a hard material that can be developed under radiation, including but not limited to nickel-titanium alloy, stainless steel, developable polymer materials, etc.

[0011] Furthermore, the first identification element cooperates with the proximal end of the thrombus removal stent to form a buckle, so that the proximal end of the stent is fixed to the middle tube.

[0012] Furthermore, the first identification element has a hollow inner cavity, and the hollow inner cavity accommodates the inner tube to pass smoothly.

[0013] Furthermore, the first identification element cooperates with a diameter limiting ring, and when the diameter limiting ring abuts against the first identification element, the thrombus removal stent is fully released to reach a maximum diameter.

[0014] Furthermore, a second identification element is provided at the distal end of the inner tube, and the second identification element is made of a hard material that can be developed under radiation, including but not limited to nickel-titanium alloy, stainless steel, developable polymer materials, etc.

[0015] Furthermore, the second identification element fixes the distal end of the thrombus removal stent to the tip to form an integral whole, and fixes the stent at the distal end of the inner tube to form a closed net bag.

[0016] Furthermore, the conveying system includes a connecting component, and the connecting component includes a conveying sheath seat, a connecting head, an intermediate tube seat, a base and a screw connecting piece.

[0017] Furthermore, the delivery sheath seat and the connector are respectively located at the proximal ends of the delivery sheath and the intermediate tube, and the delivery sheath and the intermediate tube are coaxially assembled; the delivery sheath seat and the connector have two states, separated and connected, corresponding to the first state and the second / third state of the delivery system respectively.

[0018] Furthermore, the screw connector is connected to and fixed to the screw, and the screw connector has two states: embedded and exposed, which correspond to the first / second and third states of the conveying system respectively.

[0019] Furthermore, the conveying system includes a holding component, which is an operating handle shell. The shell has an outer surface that caters to the physiological curvature of the palm. During operation, the outer surface fits the palm tightly without displacement.

[0020] Furthermore, the conveying system includes a position adjusting component, and the position adjusting component includes a screw rod, a first position limiting tube, a second position limiting tube, a stroke tube, a support tube, a support spring and a knob.

[0021] Furthermore, the positioning components are coaxially assembled.

[0022] Furthermore, the positioning components cooperate with each other to directly control the conveying system to form the first, second or third state by turning the knob.

[0023] Furthermore, the first, second or third state respectively corresponds to three states of the thrombus removal stent being compressed in the delivery sheath, being completely pushed out of the delivery sheath and being completely released and opened.

[0024] Furthermore, the transition between the second state and the third state is a continuous gradual change process, and the gradual change process is continuously adjusted by the position adjustment component.

[0025] Furthermore, when the stent is dragged backward, the third state can be actively transformed to the second state in the process of reducing the cavity diameter, and the transformation is reversible as the cavity diameter changes.

[0026] Furthermore, the active transformation process is achieved by the cooperation of a support spring and a limit ring.

[0027] Furthermore, the active transformation process can also be achieved manually by adjusting the knob.

[0028] Furthermore, the process of manually achieving state change of the adjusting knob is achieved by the cooperation of the limit ring, the knob, the screw rod, the first limit tube and the second limit tube.

[0029] Compared with the prior art, the present invention has the following beneficial effects: the delivery system provided by the present invention can be adapted to the thrombectomy stent so that it can reach most peripheral blood vessels and natural cavity anatomical parts; and can respond to changes in the diameter of the pathway in real time in both adaptive and manual adjustment modes to ensure real-time wall adhesion, thereby improving the therapeutic effect of the device, greatly reducing the risks of thrombus escape and other risks introduced by the adaptability of the device during thrombectomy, and greatly simplifying the operational difficulty of interventional devices in treating peripheral vascular embolic diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.

[0031] Figure 1 It is a schematic diagram of the overall structure of the patent of this invention;

[0032] Figure 2 It is a schematic diagram of the first state of the conveying system of the present invention;

[0033] Figure 3 It is a schematic diagram of the second state of the conveying system of the present invention;

[0034] Figure 4 It is a schematic diagram of the third state of the conveying system of the present invention;

[0035] Figure 5 It is a schematic diagram of the relationship between the internal components of the conveying system of the patent of the present invention when the inner diameter of the passage is significantly reduced. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. When describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams are not partially enlarged according to the general proportion, and this should not be used as a limitation of the present invention.

[0037] The "proximal end" involved in the patent of this invention refers to the end closer to the operator of the delivery system of the thrombectomy stent, and the "distal end" refers to the end farther from the operator of the delivery system of the thrombectomy stent.

[0038] like Figure 1 and Figure 2 As shown, the delivery system of the present invention comprises an inner tube 1, an intermediate tube 2, a delivery sheath 3, a delivery sheath handle 4 and an operating handle 5; the operating handle is composed of a positioning component, a holding component and a connecting component; at the same time, as Figure 1As shown, a thrombectomy stent adapted to the delivery system has a distal protective umbrella 61, which is connected to the cutting stent 62 by entanglement, welding or other feasible methods to form the whole of the thrombectomy stent. When working, the delivery system controls the release and compression of the protective umbrella, and the protective umbrella expands with the cutting stent, and its outer diameter is close to the inner wall of the blood vessel, thereby preventing the thrombus from floating to the distal end.

[0039] like Figure 2 The first state of the delivery system is shown: at this time, the thrombus removal bracket is completely retracted in the delivery sheath, and the screw 511 is completely located in the operating handle. At this time, the position relationship of each adjustment component is shown in the figure: the proximal end of the support spring 516 is fixed to the limit ring 111 and is just sandwiched between the first limit tube 512 and the stroke tube 514, and the end faces of the three are against each other. At the same time, the support spring 516 is located in the support tube 515 and is completely covered on the outer surface of the stroke tube 514. At this time, the inner tube 1 is pushed to the far end to the maximum stroke, driving the protective umbrella to be in a straightened and compressed state.

[0040] like Figure 3 The second state of the delivery system shown in the figure: at this time, the delivery sheath seat 531 is connected to the distal end of the operating handle to form a whole, and the stent is completely exposed from the delivery sheath in a compressed state. At this time, the position relationship of each adjustment component is as shown in the figure: the diameter limiting ring 112 is located in the protective umbrella in the compressed state and is away from the first identification element. The relative positions of the support spring 516, the limiting ring 111, and the stroke tube 514 remain consistent with the first state.

[0041] like Figure 4 The third state of the delivery system shown: At this time, the handle component is still an integral whole, the screw 511 is fully exposed under the control of the knob, and the bracket is fully released to the maximum diameter. At this time, the support spring 516 exerts force on the limit ring 111, so that the limit ring and the first limit tube 512 are against each other and away from the end face of the stroke tube 514. The limit ring drives the inner tube to move toward the proximal end, thereby driving the protective umbrella to open. The diameter limit ring 112 reaches the nearest end during the displacement of the inner tube and is against the first identification element.

[0042] like Figure 5 The state of the delivery system shown in the figure when the inner diameter of the passage where the stent is located is significantly reduced: at this time, the screw 511 remains completely exposed. The stent is squeezed and extended by the reduced passage, driving the inner tube to move relative to the distal end. At this time, the diameter limiting ring 112 is disengaged from the first identification element 121. Driven by the inner tube, the limiting ring 111 moves relative to the distal end, disengages from the end face of the first limiting tube 512, and compresses the support spring 516. During the compression process, the support spring is always located in the support tube 515, and the limiting ring is always located in the second limiting tube 513.

[0043] When the stent and the inner wall of the passage are entangled due to friction, the stent is stuck in the cavity with a larger diameter, and the adaptive mode cannot adjust its shape. At this time, the knob 517 is turned to cause the screw 511 to move distally, driving the first limit tube 512 to move distally and against the end face of the limit ring 111. Continue to rotate, the first limit tube 512 pushes the limit ring 111 to continue to move distally, thereby driving the inner tube to move distally, and then driving the protective umbrella to compress, the diameter of the protective umbrella is reduced, and it is out of the stuck state. The system can continue to withdraw.

[0044] The delivery system of the present invention can also be suitable for delivery of other interventional devices under appropriate sizes. Those skilled in the art can understand that the above description is only exemplary. That is, all equivalent changes and modifications made according to the content of the patent application scope of the present invention should be within the technical scope of the present invention.

Claims

1. A delivery system for an implantable medical device, comprising an inner tube (1), an intermediate tube (2), a delivery sheath (3), a delivery sheath handle (4), and an operating handle (5), characterized in that: The operating handle is composed of a positioning component, a holding component and a connecting component; the positioning component includes a screw (511), a first limiting tube (512), a second limiting tube (513), a stroke tube (514), a support tube (515), a support spring (516) and a knob (517); the connecting component includes a delivery sheath seat (531), a connector (532), an intermediate tube seat (533), a base (534) and a screw connecting piece (535); the proximal end of the inner tube is provided with a limiting ring (111); the limiting ring is fixed to the outer surface of the proximal end of the inner tube and is located in the operating handle; the inner tube and the limiting ring cooperate with the positioning component, The stent morphology can be adjusted in real time; the delivery system has a first state, a second state and a third state; the first state, the second state and the third state correspond to the three states of the stent being compressed in the delivery sheath, being completely pushed out of the delivery sheath and being completely released and opened, respectively; the third state can be actively transformed to the second state during the process of reducing the cavity diameter, and the transformation is reversible as the cavity diameter changes; the active transformation process is realized by the cooperation of the support spring and the limit ring, that is, the limit ring is relatively displaced toward the distal end under the drive of the inner tube, and is out of contact with the end face of the first limit tube, while compressing the support spring, and during the compression process, the support spring is always located in the support tube, and the limit ring is always located in the second limit tube.

2. The delivery system for implantable medical devices according to claim 1, characterized in that: The positioning components cooperate with each other, and the conveying system is directly controlled to form a first (71), a second (72) or a third state (73) by rotating the knob; the transition between the second state and the third state is a continuous gradual process, and the gradual process is continuously adjusted by the positioning components; the third state can be adaptively transformed to the second state during the process of reducing the cavity diameter, and the transformation is reversible as the cavity diameter changes.

3. The delivery system for implantable medical devices according to claim 1, characterized in that: The inner tube has a diameter limiting ring (112) at the distal end thereof; the diameter limiting ring is fixed to the outer surface of the inner tube at the distal end thereof and is located in the inner cavity of the thrombus removal stent.

4. The delivery system for implantable medical devices according to claim 1, characterized in that: The inner tube and the positioning component work coaxially, and the positioning component controls the inner tube to move in the axial direction.

5. The delivery system for implantable medical devices according to claim 1, characterized in that: The intermediate tube is connected to the connecting member, and during operation, the relative positions of the intermediate tube and the operating handle remain unchanged.

6. The delivery system for implantable medical devices according to claim 1, characterized in that: The delivery sheath is connected to the delivery sheath handle, and the relative positions of the delivery sheath and the delivery sheath handle remain unchanged during operation.

7. The delivery system for implantable medical devices according to claim 1, characterized in that: The distal end of the inner tube is fixed to the distal end of the delivered instrument, and the distal end of the intermediate tube is fixed to the proximal end of the delivered instrument.

8. The delivery system for implantable medical devices according to claim 1, characterized in that: The inner tube, the intermediate tube and the delivery sheath can move relative to each other in the axial direction under the control of the delivery sheath handle and the operating handle to form a first state (71), a second state (72) or a third state (73).

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