Gerard M. Guiraudon1, Douglas L. Jones2, Daniel Bainbridge3, Terrence M. Peters4.
1CSTARCSTAR. LHSC LHRI. Robarts Research Institute. Schulich Medical School.. UWO., London, ON, Canada, 2Department of Physiology and Pharmacology. Schulich Medical School. CSTARCSTAR. LHSC LHRI. Robarts Research Institute. UWO., London, ON, Canada, 3LHSC LHRI. Department of Anesthesiology. Schulich Medical School.. UWO., London, ON, Canada, 4Robarts Research Institute. Department of Biophysics. CSTAR. LHSC. LHRI. Schulich Medical School.. UWO., London, ON, Canada.
OBJECTIVE: When the left atrium is inaccessible by catheter for treatment of arrhythmia after complex surgery for congenital heart disease (CHD), such as after the Fontan or Mustard procedure, our novel closed, beating, intracardiac surgery provides a unique alternative access. We investigated minimally invasive atrial fibrillation (AF) surgery, combining epicardial and endocardial access with a state of the art electrophysiologic (EP) study, using the Universal Cardiac Introducer® (UCI), attached to the left atrial appendage (LAA) in the pig.
METHODS: Pigs had endocardial LA accessed via the UCI implanted on the LAA via a small left thoracotomy. This allowed access to both the epicardial and endocardial surfaces of the LA. Development and testing of the UCI was conducted on 13 pigs using the Flex 10® microwave probe, with introduction of the loop and its holder. The possibility of introducing, manipulating and positioning a SurgiFrost® using ultrasound guidance (TEE) for isolation of the pulmonary vein region was tested in 7 pigs. CARTO® mapping was used in 5 pigs. US imaging augmented with virtual reality displayed on a single screen was concomitantly developed in the imaging laboratory.
RESULTS: The initial experiment documented that the UCI was safe and versatile. Cryo-isolation of the PV region documented that US guidance was very helpful, despite its limitations, and allowed reproducible overlapping application of the cryoprobe. The PV region was isolated in 6 of 7 pigs. CARTO® mapping provided a comprehensive electro-anatomical display and located electrical gaps in 2 pigs. Interestingly, these gaps could be treated by epicardial cryoablation. Preoperative CT images could be registered to 2D US images or the CARTO® 3D images to provide a 3D anatomical context and facilitate effective EP study, ablation and testing. Epicardial access can complement endocardial access or address specific epicardial targets such as ganglionated plexi.
CONCLUSIONS: AF surgery via the UCI provides the ability to perform EP studies and ablation without fluoroscopic image-guidance. This approach is ready for clinical translation and will provide a unique option for patients with an inaccessible left atrium after complex surgery for CHD, or an alternative to catheter ablation in selected patients.
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