Cardiac magnetic resonance-guided robotic ablation of atrial fibrillation

Background Robotic-assisted ablation of atrial fibrillation (RA-AF) is a minimally invasive procedure that requires accurate planning and anatomical assessment to reduce the risk of complications. Cardiac Magnetic Resonance (CMR) can be safely used for pre-procedural planning, providing good quality images without the use of the ionizing radiation. Furthermore, CMR provides additional informations regarding left ventricular fibrosis, which has been associated with a higher arrhythmia recurrence rates after ablation. Purpose The aim of the study is to evaluate how CMR can be used to assist the surgeon in the planning and execution of a safe and effective robotic-assisted procedure. Methods Overall, 22 patients were evaluated for the anatomical feasibility of RA-AF with cardiac magnetic resonance (CMR) imaging and three-dimensional (3D) reconstruction of cardiac structures. 3D reconstructions of the left atrium were reviewed and discussed with surgeons before the procedure, focusing on number of pulmonary veins (PVs), their location and the relation to other structures of the thorax. Left atrial late gadolinium enhancement (LA LGE), including its location and extension, was used as a surrogate marker of disease severity, expressed in terms of the number of segments involved as determined by visual evaluation. Both Left atrial volume and degree of atrial fibrosis were used to guide the positioning of the ablation probe and the number of energy applications to achieve transmural lesions. Results LA LGE identified extensive pathological substrate on the LA roof (n=18, 81%) and lateral wall (n=10, 45%). No thrombi were detected. All patients met the anatomical characteristics suitable for robotic approach. Patients underwent CMR-guided RA-AF without intraoperative complications, as a result of preoperative planning with better surgical visualization of cardiac anatomical structures provided by the robotic technique. No conversion to full sternotomy or cardiopulmonary bypass due to cardiac lesion was observed. No major bleeding requiring re-exploration or blood transfusion was reported. Conclusion RA-AF planning with CMR and three-dimensional reconstruction of cardiac structures allows for a better anatomical assessment compared to the direct surgical/robotic visualization. CMR imaging may also have a prognostic value on the effectiveness of the ablation technique by enabling a qualitative and quantitative analysis of cardiac tissues in the preprocedural phase, with the advantage of being radiation-free.3D volume rendering CMR data