Surgical left atrial appendage occlusion: evaluation of a novel device with magnetic resonance imaging.
OBJECTIVE
Management of the left atrial appendage (LAA) is considered an important adjunct to ablation in cardiac surgical patients with atrial fibrillation (AF). However, current surgical techniques, both cut-and-sew and stapling, have been associated with incomplete LAA occlusion and complications. Using cardiac magnetic resonance imaging (MRI), we studied the safety and effectiveness of a new device for LAA occlusion in a primate model.


METHODS
Seven adult baboons underwent off-pump placement of an LAA clip (AtriCure Inc., Westchester, Ohio). LAA occlusion was confirmed intraoperatively by direct incision. All animals had MRI before and after clip placement to assess LAA perfusion, architecture, and overall cardiac function. Pathologic and histological studies were performed at 7, 30 and 180 days.


RESULTS
Clip placement was successful in all (n=7) without any clip related complications. Complete LAA occlusion was demonstrated intraoperatively in all subjects. LAA occlusion was confirmed on pre-sacrifice MRI, and left and right ventricular function were unchanged from preoperative studies; however, clip placement caused small reductions in left ventricular end-diastolic, end-systolic, and stroke volumes. At sacrifice, direct inspection confirmed stable location, persistent LAA exclusion, tissue in-growth and homogenous epithelialization without damage to adjacent structures. Histological analysis revealed a regular in-growth pattern in all studied specimens.


CONCLUSIONS
We demonstrated a safe, straightforward, persistent and effective method for LAA occlusion with this new LAA clip. MRI effectively demonstrated LAA occlusion and only minor changes in left ventricular volumes.
Salzberg
Sacha P
SP
Department of Cardiothoracic Surgery, Mount Sinai Medical Center, New York, NY, USA. sacha.salzberg@usz.ch
Gillinov
Alan Marc
AM
Anyanwu
Anelechi
A
Castillo
Javier
J
Filsoufi
Farzan
F
Adams
David H
DH
D000818:Animals; D020517:Atrial Appendage / Q000473:pathology / Q000601:surgery*; D001281:Atrial Fibrillation / Q000601:surgery; D005260:Female; D008279:Magnetic Resonance Imaging; D023421:Models, Animal; D048530:Papio anubis; D011184:Postoperative Period; D019736:Prostheses and Implants; D020521:Stroke / Q000517:prevention & control