Novel Transcatheter No-Implant LAA Closure System

Objective: The aim of the study is to evaluate the feasibility of a new approach for LAA closure by tissue invagination from within the left atrium. The aim was to demonstrate that reshaping of the LAA allows easy sealing without requiring a device implant.

Method and Sources: This ex-vivo study was conducted on 10 human cadaver hearts. The LA was opened, and a temporary anchor catheter was inserted at the LAA orifice. LAA was then sealed using a specialized reshaping suction cap while applying vacuum and pulling the LAA into the LA. The LAA was folded by the vacuum into the cap until reaching 1 atm – 700 mmHG. At the end of the procedure, only the LAA proximal tissue was invaginated into the suction cap

A ligation wire was then gently applied on the invaginated LAA base until reaching 30 newtons and was cut to form a small tissue cap that maintained complete sealing of the LAA orifice by the tissue itself.

Results: The procedure was successfully completed in 10 human cadaver hearts achieving full closure of the LAA orifice by the ligation wire in all attempts. The procedure was easily adapted to different LAA shapes and sizes and no measurements pre and during the procedure were required. The placement of a flexible nitinol anchor targets the system into the right landing zone in the LAA orifice and applying suction did not pose a technical challenge. The flexible nitinol skeleton of the suction cap covered by the medical polymer allowing full sealing of the LAA orifice while the proximal LAA tissue is reshaped by the suction cap. Closure of the invaginated tissue by the ligation wire created a tissue cap that closed LAA orifice with no additional foreign material.

Discussion: Current LAA closure systems require long term implant of foreign material which has been associated with device related thromboembolism. The described system design allows adaptation to various LAA structures and orifice sizes and may allow development of an LAA closure system requiring minimal foreign material (ligation suture only) with favorable features in terms of blood leaking and ease of use. More research is required before clinical safety and efficacy can be evaluated.