The present application relates to the field of medical devices and, in particular, to an occluder and an occluding system.
Aortic dissection (AD) is a condition in which blood flowing in the aortic lumen enters the aortic media from a breach in the aortic intima, and separates expands the tissue of the media apart along the longitudinal direction of the aorta, creating two separated true and false lumens in the aortic wall. AD is an acute, life-threatening cardiovascular disease featuring an abrupt onset, rapid progression and a very high mortality rate. In the current clinical practice, endovascular aortic repair (EVAR) is the most widely used AD therapy. In an EVAR procedure, an implant is delivered into the aortic lumen to occlude primary breach in the aortic lumen so that blood flowing in the false lumen will slow down or even stop, leading to the formation of a thrombus. With the thrombus being gradually organized and absorbed, the true lumen will restore its normal anatomy state and function to supply blood to the visceral arteries, and the aorta is finally reconstructed. Compared with other therapies (e.g., open surgery), EVAR is advantageous in less trauma, lower perioperative mortality and faster recovery.
Theoretically, once blood inflow to the false lumen disappears following the occlusion of the primary breach in the aortic true lumen, the pressure in the false lumen suddenly drops, which subsequently relieves the compression to the true lumen. As a result, recovery of the true lumen's normal anatomy will be realized over time as the false lumen gradually undergoes thrombosis and organization of the thrombosis in the false lumen. However, in practice, unsatisfactory aortic reconstruction has been observed in some AD patients who received EVAR, mainly for the reason that EVAR could occlude only the primary breach near the heart. Whereas, most AD patients often have multiple breaches and most of the multiple breaches are located around the visceral arteries (i.e., the breach being the distal breach away from the heart). At present, such distal breaches are treated mainly by (1) occlusion with additional implants, (2) aortic replacement or (3) conservative management with intensive surveillance. Approach (1) may lead to insufficient visceral blood supply that can endanger the patient's life, while approach (2) is associated with the risk of high postoperative mortality and paraplegia rates. Approach (3) may lead to insufficient postoperative expansion of the distal aortic true lumen and continuous false lumen perfusion, which may seriously affect benign reconstruction of the distal aorta and the patient's late prognosis.
For AD, the desirable surgical approach is to repair breaches for total aorta and facilitate false lumen thrombosis. At present, distal breaches are commonly occluded by occluders. As a “targeted therapy” in the field of endovascular treatment, an occluder aims for isolation of a breach without affecting blood supply to adjacent important branch arteries, which can minimize the likelihood of postoperative ischemia of important branch arteries or organ infarction. Therefore, the occluder has many advantages in AD treatment, which brings a broad clinical application value to the occluder. However, existing occluders for occluding breaches are associated with various problems. For example, the existing occluder has a slack shape after released, leading to a poor occlusion. Moreover, the existing occluder lacks anchoring means used for its fixation in a blood vessel, which results in the occlusion failure due to displacement under the impact of blood flow.
It is an object of the present application to provide an occluder and an occluding system that are capable of maintaining a predetermined configuration after released, which is able to ensure good occlusion, facilitate false lumen thrombosis and achieve true lumen reconstruction.
To this end, the present application provides an occluder comprising a body comprising a shaping wire and a spring coil, the shaping wire formed by a resilient metal wire and configured to have a predetermined shape, the spring coil sleeved over the shaping wire in order to shape the body with the predetermined shape.
Optionally, the occluder further comprises an anchoring mechanism connected to one end of the shaping wire. The anchoring mechanism is rotatable about an axis of the shaping wire and configured to secure the body onto an object.
Optionally, the shaping wire is coiled into a continuous, curved structure to form the predetermined shape.
Optionally, the predetermined shape is a helical shape, and the shaping wire is helically coiled along a certain axis to form the helical shape.
Optionally, the predetermined shape is a circular cone. The shaping wire is coiled into a plurality of arc-shaped sections connected sequentially. The plurality of arc-shaped sections are sequentially arranged in an axial direction of the circular cone and adjacent arc-shaped sections are eccentrically arranged.
Optionally, the body has a first end and a second end opposite the first end in the axial direction of the circular cone. Along a direction from the first end to the second end, the circular cone has an increased radial cross section and each of the plurality of arc-shaped sections has an increased radial size. The anchoring mechanism is provided at the second end.
Optionally, the predetermined shape is a spherical or hexahedral shape.
Optionally, the anchoring mechanism comprises a positioning portion configured to connect with the object, the positioning portion being a barb or a positioning disc
Optionally, the positioning portion is provided with a sharp end configured to pierce into an inner wall of a blood vessel to secure the body.
Optionally, the occluder further comprises thrombosis-enhancing villi attached to the body.
Optionally, the thrombosis-enhancing villi are wounded around the shaping wire and clamped and secured by the spring coil.
Optionally, at least two thrombosis-enhancing villi are arranged on the shaping wire and spaced apart from one another, and a distance between two adjacent thrombosis-enhancing villi along an axis of the shaping wire is in a range of from 5 mm to 10 mm.
Optionally, each of the thrombosis-enhancing villi has a length in a range of from 15 mm to 25 mm.
Optionally, the spring coil has an inner diameter ranging from 0.5 mm to 1.0 mm.
To achieve the above objective, the present application also provides an occluding system comprising a stent and at least one occluder as defined above. The occluder is coupled to the stent.
Compared with the prior art, the occluder and occluding system of the present application offer the following advantages:
First, the occluder comprises a body comprising a shaping wire and a spring coil, the shaping wire formed by a resilient metal wire and configured to have a predetermined shape, the spring coil sleeved over the shaping wire in order to shape the body with the predetermined shape. Through maintaining the shape of the body by means of the shaping wire, the body is able to effectively block the breach.
Second, the occluder also comprises the anchoring mechanism made of a resilient metal and provided on the body, the anchoring mechanism configured to secure the body onto an object. The anchoring mechanism enables to fix the position of the body so as to avoid displacement of the body.
Third, the anchoring mechanism is coupled to one end of the shaping wire and is rotatable about the axis of the shaping wire. In this way, the torsional effect generated by the spring coil during delivery and release of the occluder in an aorta is able to be eliminated.
Objects, advantages and features of the present application will become apparent upon reading the following detailed description with reference to the accompanying drawings. It should be noted that the drawings are provided in a very simplified form not necessarily drawn to scale, for the only purpose to facilitate convenient and explicit description of embodiments of the present application.
As used herein, the singular terms “a,” “an” and “the” include their plural referents, while the plural form such as the term “plurality” means two or more, unless the context clearly dictates otherwise. As used herein, the term “or” is generally employed in the sense including “and/or”, unless the context clearly dictates otherwise, and the terms “attach”, “couple” and “connect” in their various forms should be interpreted in a broad sense, which can for example refer to a fixed connection, a detachable connection, or an integral connection, or to a mechanical connection or an electrical connection, or to a direct connection or an indirect connection with one or more elements interposed between the connected ones, or to mutual communication between the interiors of two elements or interaction between two elements. A person of ordinary skilled in the art would be able to understand the specific meanings of these terms in this context based upon specific situations. In the figures, identical or similar reference numerals will be used to identify identical or similar elements.
As used herein, “proximal end” or “distal end” refers to the relative orientation, relative position, or direction of elements or actions that are relative to each other from the perspective of an operator operating the device. Yet without wishing to be limiting in any sense, the “proximal end” generally refers to the end of the medical device close to the operator during its normal operation, while the “distal end” generally refers to the end that enters into the body of the patient first.
During AD treatment, the body 110 is filled in the false lumen 20 and occludes a breach 30. By employing the resilient metal wire as the shaping wire 111 that is configured to have a predetermined shape, the body 110 also presents the said predetermined shape as the spring coil 112 is sleeved over the shaping wire 111. The body 110 is deformed during the delivery of the occluder 100 into a blood vessel, while returning back to the predetermined shape under the resilience force from the shaping wire 111 after the release of the occlude 100 into the blood vessel. In other words, embodiments of present application maintain the shape of the body 110 by means of the shaping wire 111 so as to effectively occlude the breach 30.
The occluder 100 further includes an anchoring mechanism 120. The anchoring mechanism 120 is made of a resilient metal. The anchoring mechanism 120 is disposed on the body 110 and connected to one end of the shaping wire. The anchoring mechanism is rotatable about an axis of the shaping wire and configured to secure the body 110 to an object.
With particular references to
The specific structure and fabrication process of the occluder 100 according to this embodiment will be described below.
The shaping wire 111 can be made of a shape memory alloy (e.g., nickel-titanium alloy, copper-nickel alloy, copper-zinc alloy or other alloy), a cobalt-chromium alloy, stainless steel or the like. The shaping wire 111 is coiled to form the predetermined shape and then subjected to the heat treatment in order to enable the shaping wire 111 to present the predetermined shape in its natural state. The shaping wire 111 deforms when an external force is applied thereto and returns back to the predetermined shape once the external force is removed.
Preferably, the shaping wire 111 is coiled to form a continuous, smooth curvilinear structure, so that the eventually formed body 110 does not have any sharp corner, which may avoid injuries to the wall of a blood vessel to result in secondary damages during implantation of the body 110.
As shown in
After that, a force is applied to the shaping wire 111 to straighten the shaping wire 111 from its predetermined shape, and the spring coil 112 is then sleeved over the shaping wire 111. Once removing the force, the shaping wire 111 returns back to the predetermined shape by virtue of its own resilience. In this way, the body 110 having the predetermined shape can be obtained (as shown in
Further, in this embodiment, the predetermined shape is a helix. For example, with combined reference to
The anchoring mechanism 120 may be made of a shape memory alloy (e.g., a nickel-titanium, copper-nickel, copper-zinc or other alloy), a cobalt-chromium alloy, stainless steel or the like. As shown in
Further, as shown in
The anchoring mechanism 120 is subjected to a significant force during the implantation of occluder 100 into the blood vessel. In order to avoid the anchoring mechanism 120 from transmitting the force to the spring coil 112 to cause detachment of the spring coil 112 from the shaping wire 111, the anchoring mechanism 120 is preferred to be connected to the shaping wire 111 and is able to rotate about the axis of the shaping wire 111.
With particular reference to
Further, as shown in
Referring to
As shown in
As shown in
As shown in
The shaping wire 111 is coiled to present a plurality of arc-shaped sections, which constitutes the spherical structure. Preferably, each of the arc-shaped sections may be approximately circular. In this embodiment, since the shaping wire 111 is coiled into the spherical structure and is also coiled inside the spherical structure, when the spring coil 112 is sleeved over the shaping wire 111 to form the body 110, there is no large void present in body 110, which helps in blocking blood flow. Moreover, during release of the shaping wire 111 that forms the spherical structure, even when the arc-shaped sections kinks, there will be sufficient room for the kinked sections to reverse and return back to the predetermined positions under the resilience of the shaping wire 111. Therefore, the overall structure of the body 110 will not be affected, and the occlusion performance of the occluder 100 will be ensured.
As shown in
On the basis of the above described occluders 100, another object of the present application is to provide an occluding system for use in AD treatment. Referring to
Alternatively, the occluding system includes at least one occluder 100. In fact, a length of the stent 200 is preferred to cover all the breaches 30 in the blood vessel. The number of occluders 100 equals to the number of breaches 30, so that each breach 30 is provided with one occluder 100 to block the blood flow into the false lumen 20, facilitating thrombosis in the false lumen 20.
In the occluder 100 and occluding system provided in embodiments of the present application, the occluder 100 includes a body 110 and an anchoring mechanism 120. The body 110 includes a shaping wire 111 and a spring coil 112. The shaping wire 111 is formed by a resilient metal wire and configured to have a predetermined shape. The spring coil 112 is sleeved over the shaping wire 111 in order to shape the body with the predetermined shape. The anchoring mechanism 120 is provided on the body 110 and configured to be coupled to an object (the stent 200). By virtue of the resilience of the shaping wire 111, the body 110 is able to maintain the predetermined shape after the release of the body 110, ensuring occlusion of a breach 30. Moreover, the anchoring mechanism 120 is configured to retain the occluder 100 at the breach 30, avoiding the displacement of the body under the effect of blood flow, which would influence the occlusion effect.
Although the present application has been disclosed above, it is not limited to the above disclosure. Those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope thereof. Accordingly, the invention is intended to embrace all such modifications and variations if they fall within the scope of the appended claims and equivalents thereof.
Number | Date | Country | Kind |
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201911349235.0 | Dec 2019 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2020/113613 | 9/4/2020 | WO |