Devices and methods for excluding the left atrial appendage

Abstract

Systems, devices and methods for occluding the left atrial appendage (LAA). The device excludes the LAA from blood flow. The implantable device is delivered via transcatheter delivery into the LAA and secured within the LAA. The implant comprises an expandable and compliant frame and an expandable and conformable tubular foam body. A delivery and tether retraction system includes a handle for controlling a pusher and tether. The pusher may be moved a distance away from the implant without changing the orientation of the implant, while the tether is still attached to the implant. Severing the tether and proximally retracting a control on the hand piece by a distance causes the severed end to advance distally by at least about twice that distance. A loader includes a conical portion with guides and a reservoir for submerging the foam prior to loading and delivery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 16 / 782,871, filed Feb. 5, 2020, which claims the priority benefit of U.S. Provisional Patent Application No. 62 / 803,289, filed Feb. 8, 2019, the entire disclosure of which is hereby incorporated by reference herein in its entirety.BACKGROUNDField[0002]This development relates generally to systems, devices and methods for excluding the left atrial appendage (LAA). In particular, systems, devices and methods for excluding the LAA using an expandable foam implant with a deployable and compliant frame are described herein.Description of the Related Art[0003]Atrial fibrillation (Afib) is a condition in which the normal beating of the left atrium (LA) is chaotic and ineffective. The left atrial appendage (LAA) is a blind pouch off the LA. In patients with Afib blood stagnates in the LAA facilitating clot formation. These clots (or clot fragments) have a tendency to embolize ...

AI Technical Summary

Benefits of technology

[0010]Devices and methods are described for occluding the LAA (LAA) to exclude the LAA from blood flow to prevent blood from clotting within the LAA and subsequently embolizing, particularly in patients with atrial fibrillation. An LAA occlusion device is delivered via transcatheter delivery into the LAA and anchored using a compliant frame and foam body. The device conforms to the oval shape of the LAA with superior sealing effect, does not require an excessive number of sizes and thus negates the need for extensive pre-procedure imaging, and can be delivered off-axis thereby allowing for simpler delivery procedure, among other advantages.

[0012]The foam body may be at least partially covered by a proximal end cover. The cover may be an expanded Polytetrafluoroethylene (ePTFE) cover. The cover provides several advantages, such as the following: sufficiently strong to enable handling of the plugs without tearing; allow for repositioning and retrieval of the plugs; provides a thromboresistant surface within the LA which will encourage formation of a neointima; assist in the creation of occlusion zones designed to encourage thromboresistance and endothelialization from the blood and adjacent tissue and anchoring zones designed to promote fast and tenacious tissue ingrowth into the compressible implant from the adjacent non-blood tissue; and can assist in closure at the ostium. The cover, e.g. a layer, jacket or skin, etc., can be independent or can be attached to the foam body, for example with sutures, adhesives, etc. In some embodiments, retrieval finials can be attached at one or more points to aid in retrieval of an embolized device and to increase radiopacity.

[0051]In another aspect, a LAA occlusion device is described. The device comprises an expandable foam body and an internal locking system. The body can be compressed for delivery within a delivery catheter and can self-expand when removed from the delivery catheter. The internal locking system is coupled with the body and comprises a deployable anchor configured to deploy from a constrained configuration within the body to a deployed configuration where the anchor extends outside the body to secure the body within the LAA. The deployable anchor is configured to retract from the deployed configuration to a retracted configuration within the body such that the body can be repositioned within the LAA.

Problems solved by technology

These clots (or clot fragments) have a tendency to embolize or leave the LAA and enter the systemic circulation.

These drugs reduce clot formation but also increase bleeding complications including hemorrhagic strokes, subdural hematoma, and bleeding in the gastrointestinal tract.

A large portion of these patients cannot take anticoagulants due to an increased bleeding risk, leaving their stroke risk unaddressed.

Existing devices for occluding the LAA have drawbacks.

This is difficult to do using fluoroscopy and often requires adjunctive imaging in the form of transesophageal echocardiography (TEE), cardiac CT and MRI, all with three dimensional reconstructions.

If the device is significantly oversized, the LAA ostium may become overstretched leading to tearing, resulting in bleeding into the pericardial space.

If the device is too small, it will not adequately seal the ostium and may be prone to embolization.

Even if sized correctly, the device forces the oval LAA ostium to take the round shape of the device, often resulting in residual leakage at the edges due to poor sealing.

If too stiff, these devices may lead to leaking of blood through the tissue into the pericardial space which may lead to cardiac tamponade.

Furthermore, the geometry of these devices limits repositioning once the implant is fully expanded.

Existing devices also complicate delivery by requiring positioning in the LAA coaxial to the axis of the LAA.

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