FIELD OF INVENTION

The present invention generally relates to medical instruments, and more particularly, to embolic implants for aneurysm therapy.

BACKGROUND

Cranial aneurysms can be complicated and difficult to treat due to their proximity to critical brain tissues. Prior solutions have included endovascular treatment whereby an internal volume of the aneurysm sac is removed or excluded from arterial blood pressure and flow. Current alternatives to endovascular or other surgical approaches can include intravascularly delivered treatment devices that either fill the sac of the aneurysm with embolic material or block the entrance or neck of the aneurysm. Both approaches attempt to prevent blood flow into the aneurysm. When filling an aneurysm sac, the embolic material clots the blood, creating a thrombotic mass within the aneurysm. When treating the aneurysm neck, blood flow into the entrance of the aneurysm is inhibited, inducing venous stasis in the aneurysm and facilitating a natural formation of a thrombotic mass within the aneurysm.

Current intravascularly delivered devices typically utilize multiple embolic coils to either fill the sac or treat the entrance. Naturally formed thrombotic masses formed by treating the entrance of the aneurysm with embolic coils can improve healing compared to aneurysm masses packed with embolic coils by reducing possible distention from arterial walls and permitting reintegration into the original parent vessel shape along the neck plane. However, embolic coils delivered to the neck of the aneurysm can potentially have the adverse effect of impeding the flow of blood in the adjoining blood vessel; at the same time, if the entrance is insufficiently packed, blood flow can persist into the aneurysm. Treating certain aneurysm morphology (e.g. wide neck, bifurcation, etc.) can required ancillary devices such a stents or balloons to support the coil mass and obtain the desired packing density. Once implanted, the coils cannot easily be retracted or repositioned. Furthermore, embolic coils do not always effectively treat aneurysms as aneurysms treated with multiple coils often recanalize or compact because of poor coiling, lack of coverage across the aneurysm neck, because of flow, or large aneurysm size.

Alternatives to embolic coils are being explored, for example a tubular braided implant is disclosed in US Patent Publication Number 20180242979, incorporated herein by reference. Tubular braided implants have the potential to easily, accurately, and safely treat an aneurysm or other arterio-venous malformation in a parent vessel without blocking flow into perforator vessels communicating with the parent vessel. Compared to embolic coils, however, tubular braided implants are a newer technology, and there is therefore capacity for improved geometries, configurations, delivery systems, etc. for the tubular braided implants.

There is therefore a need for improved methods, devices, and systems for implants for aneurysm treatment.

SUMMARY

It is an object of the present invention to provide systems, devices, and methods to meet the above-stated needs. Generally, in examples herein, an implant having an elongated portion and an expandable braided sack portion can be delivered through a catheter and implanted in an aneurysm such that elongated portion loops within the braided sack and the braided sack at least partially occludes the aneurysm neck.

An example implant can include an expandable braided sack portion, an elongated looping portion joined to the braided sack portion, and a detachment feature joined to the elongated looping portion. The implant can move from a delivery configuration to an implanted configuration. In the delivery configuration, the implant can be sized to be delivered through a lumen of a catheter to a treatment site, and in the implanted configuration, the implant can be sized to secure within an aneurysm. In the delivery configuration, the expandable braided sack portion can extend from a distal end of the implant, the elongated looping portion can extend proximally from the expandable braided sack portion, the detachment feature can be positioned near a proximal end of the implant, and the detachment feature can be detachably attached to a delivery system.

The expandable braided sack portion can be unattached to the delivery system when the implant is in the delivery configuration, in the implanted configuration, and throughout the transition from the delivery configuration to the implanted configuration during treatment of an aneurysm. In the implanted configuration, the expandable braided sack portion can be sized to contact a majority of an interior wall of the aneurysm, can contain the elongated looping portion, and can occlude some or all of the opening of the neck of the aneurysm. The expandable braided sack portion can have a free end, and in the implanted configuration, the free open end can be positioned at the aneurysm neck. In the implanted configuration the elongated looping portion can wind within the expandable braided sack portion.

In the delivery configuration the implant can have a fold at its' distal end, the expandable braided sack portion can encompass some of the elongated looping portion, and the free open end of the expandable braided sack portion can encircle the elongated looping portion. In the implanted configuration, a fold can define a boundary between the elongated looping portion and the expandable braided sack portion, and the fold can be positioned along a distal surface of the interior aneurysm wall. The fold at the distal end of the implant in the delivery configuration can be the same fold positioned along the distal surface of the aneurysm wall in the implanted configuration.

Alternatively, in the delivery configuration, the free open end can be positioned at the distal end of the implant and the implant can extend from the free open end at the distal end of the implant to the detachment feature at the proximal end of the implant. When the implant configured thusly, exits a catheter and the braided sack portion enters the aneurysm, a fold can form, and the fold can be positioned along a distal surface of the interior aneurysm wall.

The elongated looping portion and the expandable braided sack portion can be portions of a contiguous tubular braid. A fold can define a boundary between the elongated looping portion and the expandable braided sack portion, and the elongated looping portion can have a length measurable from the fold to the detachment feature. The elongated looping portion of the contiguous tubular braid can have a substantially uniform circumference along most of its length Alternatively, the elongated looping portion can have an embolic coil and the expandable braided sack portion can be a tubular braid.

When the implant is implanted and left in an aneurysm at the completion of an aneurysm treatment, the implant can include only the sack portion, the elongated looping portion, and the detachment feature. The implant need not have any other features such as additional detachment features or anchoring elements.

An example method of treating an aneurysm can include one or more of the following steps presented in no particular order, and the method can include additional steps not included here. An implant having an expandable portion and an embolic coiling portion can be provided. The embolic coiling portion can be detachably attached to a delivery system. The implant can be positioned within a microcatheter such that the embolic coiling portion extends distally from a proximal end of the implant, the expandable portion extends proximally from the distal end of the implant, and the expandable portion is unattached to the delivery system. The distal end of the microcatheter can be positioned near the aneurysm neck. The implant can be delivered through the microcatheter to the distal end of the microcatheter. The expandable portion can be expelled from the distal end of the microcatheter. The expandable portion can be expanded to contact a majority of the interior wall of the aneurysm. The embolic coiling portion can be expelled from the distal end of the microcatheter. The embolic coiling portion can be placed to wind within the expanded expandable portion. The embolic coiling portion can be detached from the delivery system.

When the implant is positioned in a microcatheter, a fold can be positioned at the distal end of the implant and the expandable portion can be positioned to encompass at least a portion of the embolic coiling portion. Alternatively, when the implant is positioned in a microcatheter, a free open end of the implant can be positioned at the distal end of the implant.

The expandable portion can be anchored to the interior wall of the aneurysm, and the expandable portion can be placed to inhibit the embolic coiling portion from exiting a sac of the aneurysm. The expandable portion can have a free open end, and the free open end can be positioned at the aneurysm neck. The implant can be folded to create a fold that defines a boundary between the expandable portion and the embolic coiling portion. The fold can be positioned near a distal surface of the interior aneurysm wall.

When the implant having the expandable portion and the embolic portion is provided, a contiguous tubular braid can be provided, and the expandable portion and the embolic portion can be portions of the contiguous tubular braid. When the embolic coiling portion of the contiguous braid is placed to wind within the expanded expandable portion, a substantially uniform circumference can be maintained along most of the length of the embolic coiling portion. Alternatively, when the implant having the expandable portion and the embolic portion is provided, a tubular braid joined an embolic coil can be provided such that the tubular braid includes the expandable portion and the embolic coil includes the embolic portion.

A detachment feature can be provided and affixed to the embolic coiling portion. The detachment feature can be detachably attached to the delivery system. To implant the expandable portion, embolic coiling portion, and the detachment feature in the aneurysm, the detachment feature can be detached from the delivery system. When the detachment feature is detached, only the expandable portion, embolic coiling portion, and the detachment feature can remain implanted in the implant.

Another example method for treating an aneurysm can include one or more of the following steps presented in no particular order, and the method can include additional steps not included here. An implant can be provided having a braided portion and an embolic portion. The braided portion can include a memory shape material and can have a spherical or globular predetermined shape. The embolic portion can be detachably attached to an implant delivery system. The implant and the delivery system can be positioned within a lumen of a microcatheter. When the implant and the delivery system is positioned in the microcatheter, the braided portion can be collapsed to fit in the lumen and positioned in the lumen to extend proximally from the distal end of the implant, the embolic portion can be positioned to extend distally from the proximal end of the implant, and the delivery system can be positioned to extend proximally from the embolic portion. The implant and the delivery system can traverse through the lumen of the microcatheter while the braided portion is unattached to the delivery system. The implant can be expelled from the microcatheter. When the implant is expelled, the braided portion can be expelled from the microcatheter and expanded to form a sack shape based on the spherical predetermined shape, the embolic portion can be expelled from the microcatheter and coiled within the sack shape of the braided portion. When the implant is expelled, an opening can be positioned in the sack shape of the braided portion can be positioned near the aneurysm neck, a fold can be positioned to define a boundary between the braided portion and the embolic portion near a distal surface of the aneurysm wall, and the embolic portion can traverse through the opening in the sack shape.

