Impact of a refined advanced design for left atrial appendage exclusion.

OBJECTIVES: Exclusion of the left atrial appendage has been proposed to reduce the risk of stroke in patients with atrial fibrillation. The aim of this study was to evaluate the feasibility and efficacy of the AtriClip PRO·V device (AOD2), now in development, for left atrial appendage exclusion in a canine model.

METHODS: The newest AtriClip design comprises a dual-spring mechanism that allows the clip to open into a 'V' shape while still providing equivalent force along the length of the beam. The AOD2's hallmark is a distal tip closure to help retain the appendage during clip closure. Six dogs were implanted via thoracotomy with the clinically available AtriClip device (AOD1) on the right atrial appendage and the AOD2 on the left. At 90 days after implantation, all devices were evaluated by epicardial echocardiography, computed tomography, gross pathology and histology. System performance at the initial surgery was evaluated as well.

RESULTS: The ease of use of the clinically available AtriClip device (AOD1) and AOD2 was deemed comparable in all cases. All animals survived for the planned 90-day duration without complications. The atrial appendages were fully occluded in all cases without device migration. On histology, all AtriClip devices demonstrated an acceptable biocompatibility response.

CONCLUSIONS: The AOD2 achieved easy, reliable and safe exclusion of the left atrial appendage, with favourable histologic findings. Once approved for clinical application, the AOD2 could provide a new therapeutic option to lower the risks of stroke in patients with atrial fibrillation.