ENDOVASCULAR MEDICAL SYSTEM INCLUDING EXPANDABLE AND COLLAPSIBLE FRAMEWORK AND METHOD USING SAME

An endovascular medical system includes an expandable and collapsible framework including a plurality of link sets joined together at hubs. Each of the link sets includes a plurality of scissors linkages connected in series. The framework is movable between an expanded position in which each of the scissors linkages are pivoted to a closed position and a collapsed position in which each of the scissors linkages are pivoted to an open position. The endovascular medical system also includes a deployment system for advancing the framework to a vascular deployment site within a vascular structure. The deployment system restricts movement of the framework from the collapsed position to the expanded position during advancement to the vascular deployment site.

DETAILED DESCRIPTION

Referring toFIG. 1, there is shown an endovascular medical system10, according to one embodiment of the present disclosure. The endovascular medical system10may include a number of components, which may be provided within a sterile, tear open package12, as is known in the art. In performing a percutaneous endovascular medical procedure, some or all of the components of the endovascular medical system10may be used, depending upon the specifics of the procedure to be performed. As should be appreciated, however, the components shown inFIG. 1might be separately packaged and/or the endovascular medical system10might also include components in addition to those shown, including components routinely used in percutaneous endovascular medical procedures.

The endovascular medical system10may include at least one wire guide14, which is a device commonly used in percutaneous medical procedures to introduce a wide variety of medical devices into a vascular structure of a patient. Generally speaking, wire guide14includes an elongate flexible body16extending from a proximal end18to a distal end20. Since wire guides are known, wire guide14will not be discussed herein in greater detail. However, it should be noted that wire guide14may be made from any of a number of known materials commonly used to manufacture medical devices and may include any of a variety of known configurations. For example, some wire guides include an elongate core element with one or more tapered sections near a distal end thereof. In the present disclosure, “proximal” will be used to refer to the end of a component or feature that is closest to a clinician, while “distal” is used to refer to a component or feature that is farthest away from the clinician. Such meanings are consistent with conventional use of the terms and, as such, should be understood by those skilled in the art.

A deployment system22, which may include any number of components, may also be provided with the endovascular medical system10. As shown in the exemplary embodiment, the endovascular medical system10may include a deployment catheter24, or sheath, which may function as a deployment device for the endovascular medical system10. The deployment catheter24generally includes an elongate tubular body26defining a lumen28extending from an open proximal end30to an open distal end32of the elongate tubular body26. The elongate tubular body26, which may be distally tapered, may be made from any common medical tube material, such as, for example, a plastic, rubber, silicone, or Teflon® material, and may exhibit both stiffness, or firmness, and flexibility. Materials as well as dimensions may vary depending on the particular application.

The endovascular medical system10may also include a deployment wire34, also referred to as a pusher wire or retraction wire, which, together with the deployment catheter24, may define the deployment system22of the endovascular medical system10. The deployment wire34may generally include an elongate flexible body36extending from a proximal end38to a distal end40and may be similar to the wire guide14in materials and/or dimensions. It should be appreciated that the wire guide14, deployment catheter24, and deployment wire34may all range in length from several inches to several feet long, and may all have wall diameters that are orders of magnitude smaller than their lengths. The deployment wire34may also include a retraction member42, which may include an open or closed loop or hook, shaped to engage a retraction hook44of an expandable and collapsible framework46of the endovascular medical system10.

The expandable and collapsible framework46, which will be discussed in greater detail below, may be introduced into a vascular structure of a patient using the deployment system22described herein, or using an alternative deployment system or device. For example, the retraction member42of the deployment wire34may be engaged with the retraction hook44of the expandable and collapsible framework46to define an engaged configuration. In the engaged configuration, the deployment wire34and the expandable and collapsible framework46may be advanced together through the lumen28of the deployment catheter24, with inner walls48defining the catheter lumen28restricting radial movement, or expansion, of the expandable and collapsible framework46during the advancement. As should be appreciated, the deployment wire34may require a stiffness sufficient for advancing and/or retracting the expandable and collapsible framework46through the deployment catheter24. Although a hook and loop type engagement is shown, it should be appreciated that any type of releasable connection between the deployment wire34and the expandable and collapsible framework46may be used.

Although not shown, a handle or retraction mechanism may be provided at the proximal end30,38of one or both of the deployment catheter24and the deployment wire34to aid in the deployment and/or retraction of the expandable and collapsible framework46. In particular, for example, a handle may be provided to facilitate movement of the deployment wire34, and the expandable and collapsible framework46, relative to the deployment catheter24. Such movement allows the expandable and collapsible framework46to be positioned distally beyond a distal tip50of the deployment catheter24such that the framework46is no longer restricted from radial movement, or expansion, by the catheter lumen walls48. Although a particular deployment system22is shown, it should be appreciated that any deployment system or device capable of advancing the expandable and collapsible framework46through a vascular structure in a collapsed position and allowing movement of the framework46into an expanded position at a vascular deployment site is contemplated.

As shown inFIGS. 2 and 3, the expandable and collapsible framework46includes a plurality of link sets60joined together at hubs62. Each of the link sets60includes a plurality of scissors linkages64connected in series. The expandable and collapsible framework46is movable between a collapsed position, shown inFIG. 2, in which each of the scissors linkages64are pivoted to an open position, and an expanded position, shown inFIG. 3, in which each of the scissors linkages64are pivoted to a closed position. As shown, the expandable and collapsible framework46may have a spherical shape in both of the collapsed and expanded positions, with the framework46having an increased diameter in the expanded position. To be clear, outer points of the expandable and collapsible framework46may define a spherical shape, with the diameter of the spherical shape at least doubling when the framework46is moved from the collapsed position to the expanded position.

Referring also toFIGS. 4 and 5, a portion of the link sets60may define a continuous ring, or circle,70. The continuous ring70is collapsed, as shown inFIG. 4, when each of the scissors linkages64is pivoted about a respective pivot axis72toward an open position, and is expanded, as shown inFIG. 5, when each of the scissors linkages64is pivoted toward a closed position. In particular, each of the scissors linkages64includes links74and76. The links74and76have opposing ends74aand74band opposing ends76aand76b, respectively, and are joined together at the pivot axis, or pivot joint,72. The pivot joint72of the links74and76, which may be non-linear or curved, may be offset with respect to a center of the links74and76, depending on the position of the scissors linkage64. To form the continuous ring70, ends74aand76aare connected, such as at pivot joints, with opposing ends74aand74bof a sequential scissors linkage64. The scissors linkages64are pivoted toward an open position when ends74aand76aand ends74band76bare moved away from one another. Alternatively, the scissors linkages64are pivoted toward a closed position when ends74aand76aand ends74band76bare moved toward one another, as shown inFIG. 5.

As used herein, a closed position of the scissors linkages64may include positions in which an angle a defined by the links74and76, as called out inFIGS. 4 and 5, is about 90 degrees or less. An open position of the scissors linkages64may include positions in which the angle a is about 90 degrees or greater. As should be appreciated, the collapsed position of the continuous ring70, as shown inFIG. 4, corresponds to the collapsed position of the expandable and collapsible framework46shown inFIG. 2. The expanded position of the continuous ring70, as shown inFIG. 5, corresponds to the expanded position of the expandable and collapsible framework, as shown inFIG. 5.

As shown, the expandable and collapsible sphere46may include at least three continuous rings70. In particular, the expandable and collapsible sphere46may include a first continuous ring70athat lies in a plane parallel to the x-axis, a second continuous ring70bthat lies in a plane parallel to the y-axis, and a third continuous ring70cthat lies in a plane parallel to the z-axis. In particular, each of the continuous rings70may lie in a plane that interests a center of the spherical shaped expandable and collapsible framework46. Each of the continuous rings70may be interconnected at the hubs62referenced above. In particular, a hub62may include a location at which more than two sets of scissors linkages64are connected. As shown, additional link sets60, which may not define continuous rings70, may also be provided, and may be interconnected with the continuous rings70at hubs62.

Referring toFIG. 6, there is shown a vascular structure V of a patient having a needle90, or introducer, positioned therein, at a first stage of an exemplary percutaneous endovascular procedure. The procedure, further described herein, may include a vascular occlusion procedure, a stent placement procedure, or a vascular filter placement procedure, to name a few. At a next stage of the procedure, a clinician may insert the wire guide14through a tube of the needle90and into the vascular structure V such that the distal end20of the wire guide14is at or near a vascular deployment site92. After the wire guide14is properly positioned, the needle90may be removed and the deployment system22, or components thereof, may be inserted over the wire guide14, as is known in the art. Thereafter, the wire guide14may be removed.

As shown inFIG. 7, the expandable and collapsible framework46may be advanced to the vascular deployment site92within the vascular structure V in the collapsed position ofFIG. 2. In particular, the catheter lumen walls48may restrict movement of the expandable and collapsible framework46from the collapsed position to the expanded position. The deployment system22may then be reconfigured to allow movement of the expandable and collapsible framework46from the collapsed position to the expanded position. Specifically, for example, one or both of the deployment catheter24and the deployment wire34may be moved relative to the other such that the expandable and collapsible framework46is no longer restricted form radial movement by the catheter lumen walls48. As such, the expandable and collapsible framework46may be moved from the collapsed position (FIG. 2) to the expanded position (FIG. 3), as shown inFIG. 8. In particular, each of the scissors linkages64may be pivoted from the open position to the closed position, as described above.

According to some embodiments, the expandable and collapsible framework46may be self-expanding from the collapsed position to the expanded position. As such, the expandable and collapsible framework46may be made from a resilient or shape memory material, such as, for example, nitinol, that is capable of self-expanding from the collapsed position to the expanded position. In particular, the expandable and collapsible framework46may be restricted from self-expansion using the deployment catheter24. Once the deployment catheter24is advanced to the vascular deployment site92, the deployment system22may be reconfigured such that the expandable and collapsible framework46is no longer restricted from radial expansion by the deployment catheter24. As a result, the expandable and collapsible framework46self-expands to an expanded diameter. As should be appreciated, the expandable and collapsible framework46may be selected to provide the desired expanded diameter for a particular application or procedure.

Alternatively, as shown inFIG. 9, an inflatable balloon100may be positioned within the expandable and collapsible framework46such that the inflatable balloon100may be inflated to move the framework46from the collapsed position to the expanded position. According to such an embodiment, a deployment catheter102may be used that includes a first lumen104for deployment of the expandable and collapsible framework46via the deployment wire34, and a second lumen106fluidly connected with an interior108of the inflatable balloon100and defining an inflation lumen106for the inflatable balloon100, as is known in the art. According to this exemplary embodiment, the expandable and collapsible framework46may remain attached to the deployment catheter102and/or the deployment wire34during the procedure.

According to other embodiments, it may be desirable to detach the expandable and collapsible framework46from the deployment catheter24, or deployment catheter102, and the deployment wire34. For example, as shown inFIG. 10, the deployment wire34may be detached from the expandable and collapsible framework46by disengaging the retraction member42of the deployment wire34from the refraction hook44of the framework46. The deployment catheter24and deployment wire34may then be withdrawn from the vascular structure V, leaving the expandable and collapsible framework46in place. According to a particular use, and as shown inFIG. 10, a flow restriction membrane120may be supported on the expandable and collapsible framework46and, thus, may allow the expanded framework46to act as an occlusion device within the vascular structure V. The flow restriction membrane120may include a biocompatible material capable of reducing or restricting blood flow.

The expandable and collapsible framework46may also provide artificial occlusion using embolic devices130positioned within the framework46. For example, as shown inFIG. 11, an embolic device delivery catheter132may be inserted through the deployment catheter24and used to delivery a plurality of embolic devices130, such as embolic coils134or other occlusive material, into the expandable and collapsible framework46in a known manner. After delivery of the embolic devices130into the expandable and collapsible framework46, one or both of the catheters24and132may be removed from the vascular structure V.

According to additional uses, and as shown inFIG. 12, the expandable and collapsible framework46may be used as a stent to exert a radial force against walls140of the vascular structure V. An alternative expandable and collapsible framework146may be provided in a semispherical shape, as shown inFIG. 13, and, when expanded within the vascular structure V, may act as a filter. For example, the expandable and collapsible framework146may collect clots150, such as clots150dislodged from walls152of the vascular structure V.

When desired, the expandable and collapsible framework46may be withdrawn from the vascular structure V by engaging the retraction member42of the deployment wire34with the retraction hook44of the framework46. While in the engaged configuration, the deployment wire34, or retraction device, and the expandable and collapsible framework46may be withdrawn from the deployment catheter24and, thus, the vascular structure V. While retracting the expandable and retractable framework46into the deployment catheter24, the catheter lumen walls48will exert a force against the expandable and collapsible framework46and move the framework46from the expanded configuration to the collapsed configuration.

INDUSTRIAL APPLICABILITY

The present disclosure is generally applicable to endovascular medical systems and devices. More specifically, the present disclosure is applicable to endovascular medical devices reliable and effective for use in a variety of different percutaneous endovascular procedures. Yet further, the present disclosure is applicable to an endovascular medical device that may be used for a variety of purposes, including, for example, vascular occlusion, vascular wall support or repair, and vascular filtration.

Referring generally toFIGS. 1-14, an endovascular medical system10may generally include an expandable and collapsible framework46, and a deployment system22for delivering the framework46to a vascular deployment site92within a vascular structure V of a patient. In particular, the deployment system22, which may include one or more devices, may restrict movement of the expandable and collapsible framework46from a collapsed position, for transporting the framework46, to an expanded, or deployed, position. When properly positioned, the expandable and collapsible framework46may be moved from the collapsed position to the expanded position.

The expandable and collapsible framework46may be made from a shape memory material and may be configured to self-expand when the framework46is no longer restricted from radial movement by the deployment system22. In particular, the expandable and collapsible framework46may be positioned within a deployment catheter24and engaged with a deployment wire34configured to move the framework46between its collapsed position, in which catheter lumen walls48restrict radial movement of the framework46, and its expanded position, in which the catheter lumen walls48no longer restrict radial movement of the framework46. One or both of the deployment catheter24and deployment wire34may be moved relative to the other such that the expandable and collapsible framework46is moved distally beyond a distal tip50of the deployment catheter24.

As an alternative to a self-expanding framework, the expandable and collapsible framework46may include an inflatable balloon100positioned therein and configured to move the framework46from the collapsed position to the expanded position during inflation in a known manner. According to such an embodiment, the deployment system22may include inflation and deflation means for the inflatable balloon100. For example, an alternative deployment catheter102may be used that includes one lumen104for receiving the deployment wire34and the expandable and collapsible framework46, and an inflation lumen106in fluid communication with an interior108of the inflatable balloon100via openings through the catheter102. Thus, as should be appreciated, a fluid source may be used to inflate the inflatable balloon100via the inflation lumen106.

In the expanded position, the expandable and collapsible framework46may have a number of different uses. For example, the expandable and collapsible framework46may be used to create an artificial blockage, or occlusion, within the vascular structure V. According to the embodiment utilizing an inflatable balloon100, the inflatable balloon100, received within the expandable and collapsible framework46, may restrict blood flow downstream from the framework46. Alternatively, a flow restriction membrane120may be supported on the expandable and collapsible framework46and, when the framework46is in the expanded position, may restrict blood flow beyond the framework46. Yet alternatively, as shown inFIG. 11, embolic devices130, such as embolic coils134, may be packed within the expandable and collapsible framework46, in its expanded position, to restrict or reduce blood flow.

Such an embolization procedure may be useful to treat several conditions, including, for example, aneurysms, hemorrhages, and lesions or growths. In addition, an embolization procedure may be used to isolate a treatment area from general circulation. For example, if a toxic agent, such as a chemotherapeutic agent, is delivered to a specific treatment site, it may be desirable to prevent circulation of the toxic agent downstream from the treatment area. As such, one or more artificial blockages may be created to effectively isolate the treatment area. The expandable and collapsible framework46may be detached from the deployment system22or may remain attached to the deployment system22, depending on the particular embodiment used and the particular procedure being performed.

The expandable and collapsible framework46may also be used as a stent. For example, the expandable and collapsible framework46may be deployed at the vascular deployment site92to reinforce, repair, or otherwise provide support for the vascular structure V, or other body lumen. For example, when a patient suffers from atherosclerosis, the expandable and collapsible framework46, in the expanded position, may be placed in a coronary or a peripheral artery at a location where the artery is weakened or damaged. The expandable and collapsible framework46, once in place and in the expanded position, may reinforce that portion of the artery, thereby restoring normal blood flow through the vessel.

An alternative expandable and collapsible framework146having a semispherical shape, as shown inFIG. 13, may be positioned within the vascular structure V to filter clots from the blood flow. For example, the expandable and collapsible framework146, which may be delivered and removed from the vascular deployment site92, as described herein, may be positioned downstream from a clot150, such as during a clot removal procedure. In the expanded position, the expandable and collapsible framework146may exert sufficient radial force against the vascular walls140,152to maintain a desired position of the framework46. As portions of the clot150are broken down or removed from the vascular structure walls140,152, the expandable and collapsible framework146, which may include a flow restriction membrane120supported thereon, may capture clots150for removal from the vascular structure V.

The endovascular medical system including the expandable and collapsible framework described herein provides a multi-purpose device that is reliable and effective and may be used in a variety of different endovascular procedures. By utilizing a framework having the link sets described herein, the expandable and collapsible framework is capable of maintaining a desired shape in both its collapsed and expanded positions. As such, the expandable and collapsible framework may provide a structure having a controlled and predictable expansion that may be used reliably and effectively for a variety of endovascular procedures, as described herein.