Although the relevance of surgical ablation both on the atrial epicardium, on the beating heart, and on the endocardium, during open heart operations, is becoming increasingly clear, some aspects possibly influencing clinical outcome are still under investigation.
Epicardial ablation with radiofrequency, which is today the first choice treatment modality for over 80% of the surgical ablation procedures for atrial fibrillation, was introduced in the clinical practice in 1999 by our group.
With a quite original study setup, adopting strategically placed standard epicardial pacing wires, we have investigated the appropriateness and the chronic electrophysiologic efficacy of different ablation devices available for clinical use both in Europe and in the US. In fact, while most ablation devices provide ablation lines which are acutely transmural, the chronic performance of such ablations is totally unknown. By measuring the actual degree of block output produced by ablations, in collaboration with the laboratories of electrophysiology, we have studied high-intensity ultrasound and both irrigated and temperature-controlled dry bipolar radiofrequency, identifying more effective ways to deliver surgical ablation.
Our research group also focused on molecular, histological and metabolic aspects of the atrial myocardium of patients with atrial fibrillation. We could demonstrate structural tissue, cellular remodeling, and molecular changes of oxidative stress which were more pronounced in the posterior left atrium.
At present, feasibility studies with new ablations technologies are being set in our experimental hybrid facilities, to further investigate how to deliver more effective epicardial therapies on the beating heart. This perspective is in the direction of complete close chest treatment, with no need of endovascular catheters.
Fig. 1 Evaluation of acute and chronic electrophysiological efficacy of ablation with ultrasound
Our group was the first to report on epicardial device exclusion in the clinical setting, both in concomitant operations and as a solo treatment. Our clinical research on ablated patients has proven the possibility of a complete restoration of a normal heart function after surgical ablation, even in patients with end stage heart failure refractory to multiple percutaneous ablation.
Fig. 2 Evaluation of acute and chronic electrophysiological efficacy of ablation with irrigated radiofrequency