Micro-Macro Endovascular Occlusion Device and Methodology

Abstract

A vascular plug comprises a superstructure expandable from a collapsed percutaneous insertion configuration to an expanded deployment or use configuration. The superstructure is comprised of both primary and secondary three-dimensional shapes allowing for the occlusion of a wide range of vessel sizes from small to large through a disproportionately small delivery catheter. The plug includes a shape memory element for the generation of radial force and the creation of the larger secondary three-dimensional twisting or helical superstructure as is needed for target vessel occlusion.

Description

BACKGROUND OF THE INVENTION[0001]The present disclosure generally relates to a device and methodology for occluding arterial and venous blood vessels under a variety of pathologic conditions. Many endovascular devices exist for occluding blood flow including coils, detachable balloons, and most recently expandable mechanical occlusive devices with or without coverings impervious to blood flow. Coils can be covered with fibers or coated with material such as hydrogel to enhance clot formation. Despite these features many coils are often required to occlude blood flow increasing procedure time and potentially cost. Coils can also be unreliable with regards to their geometry and vascular space filling properties after deployment. In addition coils and or clot can easily migrate distally under high flow condition such as arteriovenous fistula in the lungs or elsewhere in the body. Blood vessels occluded by coils can reopen or recanalize as has been reported in pulmonary arteriovenous fi...

AI Technical Summary

Benefits of technology

[0021]A vascular occlusion device in accordance with the present invention may be covered with an impervious membrane, uncovered, or alternatively coated with various thrombogenic materials such as small fibers or hydrogel to engender thrombosis by the three-dimensional spiraling superstructure or scaffolding after deployment. The porosity of an uncovered plug wall or body may be selected so as to promote thrombosis; changing the weave pattern or design of the stent body may be done to lower the porosity of the plug wall, and hence increase its throbogenicity. A low porosity device has minimal flow through it; a zero porosity device is impervious to flow. A plug wall with the lowest porosity possible while still maintaining the desired primary and secondary plug properties and shapes is ideal. An uncovered low porosity plug can have an overall lower profile relative to even a thinly covered plug.

[0022]The porosity of the wall of a vascular plug or medical occlusion device in accordance with the invention can be tailored to different clinical and pathologic conditions. A very low porosity plug is more thrombogenic than a higher porosity plug, while a higher porosity plug would be less susceptible than a low porosity plug to migration under the conditions of high flow, enabling the operator to create an initial stable construct or scaffolding with one or more uncovered higher porosity plugs, with subsequent placement of one or more covered or very low porosity devices in order to complete vessel occlusion.

[0023]The intraplug porosity of a given occlusion device or plug may also be varied from an upstream portion of the plug to a downstream portion. The upstream portion of the plug could have a low porosity to promote stasis and thrombosis, while the downstream portion could have a higher porosity to allow for blood flow into and out of a lumen of the plug, facilitating device repositioning or removal prior to final plug deployment. A partially porous covering plug membrane could be provided on the downstream end of a plug to achieve a similar result: transient limited flow through the plug body to reduce the chances of migration with subsequent thrombosis.

[0024]An uncovered plug may be coated with an expanding hydrogel material, which would be activated after c

Problems solved by technology

Despite these features many coils are often required to occlude blood flow increasing procedure time and potentially cost.

Coils can also be unreliable with regards to their geometry and vascular space filling properties after deployment.

Detachable balloons can be difficult to navigate through blood vessels and can prematurely detach.

Premature balloon detachment can lead to migration and occlusion of normal blood vessels resulting in complications.

Balloons can deflate over time resulting in recurrence of the treated vascular pathology such as has been reported in caroticocavernous fistula.

This device may not immediately lead to thrombosis particularly in patients with clotting disorders, requiring more than one device.

The device can be difficult to deliver and precisely deploy.

In addition the device may not provide long-term occlusion, which has been reported in pulmonary arteriovenous fistula in particular.

The largest MVP microcatheter deliverable covered plug can only treat vessels up to 5 mm in diameter, a distinct disadvantage.

Larger MVP covered plugs require delivery through 4 or 5 French catheters depending on the target vessel size; these larger catheters are often too big and rigid to easily traverse the desired vasculature.

The use of these larger 4 and

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