1. Field of Invention
The present invention relates to medical devices. More particularly, the invention relates to an occlusion device for occluding a lumen of a blood vessel.
2. Background
Vascular occlusion devices are surgical implants that are placed within the vascular system of a patient. There are a number of reasons why it may be desirable to occlude a vessel. For example, the site of a stroke or other vascular accident can be treated by placing an occlusion device proximal of the site to block the flow of blood to the site, thereby alleviating leakage at the site. An aneurysm can be treated by the introduction of an occlusion device through the neck of the aneurysm. Tumours can be treated by occluding the flow of blood to a targeted site of interest.
Several known occlusion devices include a coil having fibers, threads or strands attached to the coil. Such occlusion devices act to block the flow of blood through a vessel by the formation of an embolus in the vessel. While these occlusion devices can provide effective occlusion, they suffer from the disadvantage that blood flow continues until the embolus has been formed, thus requiring additional time before effective occlusion is obtained.
Plug-style occlusion devices have also been developed. While these are intended to provide a physical barrier to blood flow, and thereby stop blood flow more quickly, known devices are generally bulky and often require thrombosis in order for reliable occlusion to be obtained.
The present invention provides an improved occlusion for use in various medical procedures and a method of fabricating the occlusion device. One embodiment of an occlusion device, constructed in accordance with the teachings of the present invention, generally comprises a tube having a proximal end extending to a distal end and a tubular wall defining a lumen formed therethrough. The tube defines a first collar at the proximal end and a second collar located between the proximal and distal ends. A plurality of cuts formed through the tubular wall defines a plurality of radially expandable struts. The struts are biased to a radially expanded state. The plurality of struts defines a bulbous portion extending between the first and second collars and a first conical portion extending from the second collar to the distal end of the tube. The bulbous portion is configured to expand to a first maximum diameter and the first conical portion is configured to expand to a second maximum diameter approximately equal to the first maximum diameter.
In another embodiment, an occlusion device comprises a frame including a plurality of radially expandable struts. The struts are comprised of a tube having a proximal end extending to a distal end and a tubular wall defining a lumen formed therethrough. A plurality of cuts formed through the tubular wall defines the plurality of struts. The plurality of cuts includes a first set of cuts extending from a first collar at the proximal end of the tube to a second set of cuts. The second set of cuts extend from the first set of cuts to a second collar located between the proximal and distal ends of the tube. A third set of cuts extend from the second collar to the distal end of the tube.
In this embodiment, the plurality of struts is biased to a radially expanded state in which the frame includes a first conical portion defined by the first set of cuts, a second conical portion defined by the second set of cuts, and a third conical portion defined by the third set of cuts. Each conical portion has an apex and a base. The first and second conical portions are joined at their respective first and second bases forming a bulbous portion of the frame. The first collar defines a first apex of the first conical portion and the second collar defines a second apex of the second conical portion. The third conical portion is arranged distally of the bulbous portion, wherein the second collar defines a third apex of the third conical portion and the device terminates with a third base of the third conical portion at the distal end of the tube. The first set of cuts is formed in a first pattern, the second set of cuts is formed in a second pattern, and the third set of cuts is formed in a third pattern. The first pattern is different than the second pattern such that the struts of the first and second conical portions of the bulbous portion form different patterns.
In another embodiment, the present invention provides a method of fabricating an occlusion device. The method includes cutting a plurality of cuts through a portion of a tubular wall of a tube having a proximal end and a distal end. The tubular wall defines a lumen formed through the proximal and distal ends of the tube. Cutting a plurality of cuts through the tubular wall defines a plurality of radially expandable struts. The method further includes expanding the plurality of struts. In the expanded state, the struts define a frame having a first collar at the proximal end of the tube and a second collar disposed between the proximal and distal ends of the tube. A bulbous portion extends between the first and second collars and a flared portion extends from the second collar to the distal end of the tube. Expanding the plurality of struts includes expanding the bulbous portion and the flared portion to approximately the same maximum diameter.
Further objects, features, and advantages of the present invention will become apparent from consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
a is a side view of the occlusion device of
b is a side view of the occlusion device of
c and 3d are side views of the occlusion device of
e is a side view of the occlusion device of
The following provides a detailed description of currently preferred embodiments of the present invention. The description is not intended to limit the invention in any manner, but rather serves to enable those skilled in the art to make and use the invention.
In this description, when referring to an introducer or deployment assembly, the term distal is used to refer to an end of a component which in use is furthest from the physician during the medical procedure, including within a patient. The term proximal is used to refer to an end of a component closest to the physician and in practice in or adjacent an external manipulation part of the deployment or treatment apparatus. Similarly, when referring to an implant such as an occlusion device the term distal is used to refer to an end of the device which in use is furthest from the physician during the medical procedure and the term proximal is used to refer to an end of the device which is closest to the physician during the medical procedure.
The present disclosure generally provides an occlusion device and an occlusion device delivery system that may be used by a physician to deliver an occlusion device into the vasculature of a patient. Referring to
As depicted in
In this embodiment, the bulbous portion 30 could be said to include two conical portions 30a and 30b joined together such that the device 10 includes a total of three conical portions. Each conical portion 30a, 30b and 32 could be said to include a base and an apex. For example, the conical portion 30a of the bulbous portion 30 includes an apex at about the first collar 20 and extends to a base at about where the maximum outer diameter of the expanded bulbous portion 30 is approximately d1. The conical portion 30b of the bulbous portion 30 includes a base at about where the maximum outer diameter of the expanded bulbous portion 30 is approximately d1 and extends to an apex at about the second collar 22. Thus, the conical portions 30a and 30b are joined together at their respective bases to define the bulbous portion 30. In addition, the distal conical portion 32 includes an apex at about the second collar 32 and extends to a base at the most distal end 16 of the tube 12. As shown in
As shown, the conical portions 30a and 30b are each defined by a different pattern such that about one half of the bulbous portion 30 has one pattern and about another half of the bulbous portion 30 has a different pattern. Preferably, the distal conical portion 32 is defined by substantially the same pattern as its adjacent conical portion 30b of the bulbous portion 30 such that they are essentially mirror images of one another.
In this embodiment, the conical portion 30a is defined by a first set of cuts 24 formed through the tubular wall 17. The first set of cuts 24 extend from the first collar 20 (i.e., the apex of the conical portion 30a) to about where the expanded bulbous portion 30 defines the maximum outer diameter d1 (i.e., the base of the conical portion 30a) to define a first pattern. The conical portion 30b is defined by a second set of cuts 24 formed through the tubular wall 17. The second set of cuts 24 extend from about where the expanded bulbous portion 30 defines the maximum outer diameter d1 (i.e., the base of the conical portion 30b) to the second collar 22 (i.e., the apex of the conical portion 30b) to define a second pattern. The distal conical portion 32 is defined by a third set of cuts 24 formed through the tubular wall 17. The third set of cuts 24 extend from the second collar 32 (i.e., the apex of the distal conical portion 32) to the distal most end 16 of the tube 12 to define a third pattern.
As provided above, the conical portion 30b and the distal conical portion 32 are essentially mirror images of each other. Thus, the second pattern of the conical portion 30b and the third pattern of the distal conical portion 32 are substantially the same, while the first pattern of the conical portion 30a is unique in comparison.
As best illustrated in
The cuts 24 formed through the tubular wall 17 of the tube 12 are preferably formed by laser-cutting the tube 12. The laser-cut tube 12 is of a material that allows the device 10 to be self-expanding. For example, the tube 12 may be formed from a shape-memory alloy (such as Nitinol), a shape-memory polymer, or may be formed from other self-expandable materials, such as spring steel.
As illustrated in
Instead of a membrane 40, fibers could be provided on or within the occlusion device 10. These fibers may be silk, nylon, PET, or electrospun PTFE, for example.
In this embodiment, the substantially similar second and third patterns are preselected so that the device 10 provides effective occlusion regardless of the direction of blood flow, from right to left or from left to right in
The device 10 is sized so that in its expanded configuration its outer diameter at its widest point (e.g., d1 and d2) is greater than that of the blood vessel 60 into which it is to be placed. For example, in a vessel 60 having a diameter of about 8 mm, the maximum outer diameter d1 of the bulbous portion 30 and the maximum outer diameter d2 of the distal conical portion 32 are preferably about 9 mm or about 10 mm. This results in some compression of the device in situ.
Thus, the device 10 preferably has substantially the same oversizing in both the bulbous portion 30 and the distal conical portion 32. The term “oversizing” can be described with the following example: a device having an outer diameter of about 10 mm implanted into a blood vessel with a diameter of about 8 mm results in an oversizing of about 2 mm. In this embodiment, the same oversizing of the bulbous portion 30 and the distal conical portion 32 results in about the same force exerted by the bulbous portion 30 and the distal conical portion 32 against the vessel wall 62 during expansion of the device 10 within the blood vessel 60. Thus, the vessel wall 62 exerts a more even distribution of return force upon the device 10 during expansion thereof compared to a device in which the maximum diameters d1 and d2 are not equal to one another.
The degree of oversize will generally be less than about 50%, or more preferably about 25% or less. The degree of oversize desired depends on many factors, such as in which blood vessel the device is to be located (for example, artery or vein), the rate of blood flow at the desired location, and even on the medical condition of the patient. For some implementations, there may be no oversize at all.
As shown, the distal conical portion 32 includes a plurality of radiopaque markers 46. The radiopaque markers 46 may be made from gold, tantalum, palladium, platinum or any other suitable material recognized by one of ordinary skill in the art.
a-e depict deployment of the occlusion device 10 within a blood vessel 60 via a delivery system 70. The delivery system 70 includes an outer sheath 72, an inner sheath 74 housed within the lumen of the outer sheath 72, and a pusher member 76 housed within the lumen of the inner sheath 74. In this embodiment, the first collar 20 of the occlusion device 10 includes a notch 50 or some type of aperture for engaging with the pusher member 76. The pusher member 76 includes an attachment member 78 at a distal end thereof for retaining the occlusion device 10. For example, as shown, the pusher member 76 includes a hook 78 for engaging in the notch 50. Alternatively, the attachment member 78 may include any other type of attachment mechanism, such as one that can be used over a guide wire as described in U.S. Provisional Application No. 61/072,903, the entire contents of which are incorporated herein by reference.
Referring to
Once the delivery system 70 is properly positioned at a desired location within the blood vessel 60, the outer sheath 72 is withdrawn in a proximal direction to allow the distal conical portion 32 of the occlusion device 10 to expand within the blood vessel 60 as can be seen in
At this stage of deployment, the physician can readily monitor the positioning of the occlusion device 10 using the radiopaque markers 46, and if necessary, withdraw the occlusion device 10 back into the outer sheath 72 to allow repositioning.
Once the distal conical portion 32 of the occlusion device 10 has been properly positioned, the outer sheath 72 can be withdrawn further to allow the bulbous portion 30 to expand. This is illustrated in
In the next stage of deployment shown in
In the final stage of deployment, the attachment member 78 of the pusher member 76 is disengaged from the notch 50 at the proximal end 14 of the occlusion device 10. The pusher member 76 and the inner sheath 74 within the outer sheath 72 are fully withdrawn from the blood vessel 60, leaving only the occlusion device 10 fully deployed within the blood vessel 60, as shown in
During deployment, contrast injection can be used to verify the position of the occlusion device 10. If adjustment is required, the device can be retracted back into the inner and outer sheaths 74 and 72 to be relocated.
While the above method describes a preferred method of deployment, a person of ordinary skill in the art will appreciate that other deployment methods are possible. For example, deployment of the occlusion device 10 may be over a guide wire 80 (as shown and further described with respect to the embodiment in
The embodiments of the present invention have many advantages. The occlusion device 10 has a low profile because it is cut out of a very small tube. Laser-cutting allows compression of the occlusion device 10 back to a very thin tube, which is ideal for delivery. The bulbous portion 30 and the distal conical portion 32 of the occlusion device 10 assist in maintaining the occlusion device 10 in the correct orientation such that the longitudinal axis X of the device 10 is aligned with the axis of the blood vessel 60 at the point of occlusion. Furthermore, the planes of the widest parts of the bulbous portion 30 and distal conical portion 32 are substantially perpendicular to the axis of the blood vessel 60. The diamond shapes formed by the struts 26 in the distal conical portion 32 and the conical portion 30b of the bulbous portion 30 assist in retractability of the occlusion device 10 because they provide a continuous structure that would not snag on the distal end of the delivery system 70. Moreover, the embodiments of the present invention provide faster occlusion than prior art coil embolization devices. Additionally, the occlusion device 10 has a lower profile and is shorter and less bulky than prior art vascular plugs.
Further illustrated in
In this embodiment, a guide wire 80 is shown extending through the lumen 118 of the tube 112. Deployment of the occlusion device 110 over the guide wire 80 facilitates precise delivery of the occlusion device 110 within the blood vessel 60.
Further illustrated in
As a person skilled in the art will readily appreciate, the above description is meant as an illustration of the implementation of the principles of this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification variation and change, without departing from the spirit of this invention, as defined in the following claims.