Left atrial ablation through monolateral thoracotomy

We read with interest the recent paper of Solinas et al.[1], who first described a technique to perform a left atrial (LA) ablation with bipolar irrigated radiofrequency (RF) through a single right thoracotomy.This work confirms the feasibility of pulmonary veins isolation (PVI) through the monolateral approach and therefore sustains the use of minimally invasive surgery (MIS) for the treatment of atrial fibrillation (AF).However, two questions about the treatment of AF are currently unanswered: What is the best approach?What is the best lesion set?Wolf et al.[2], using a bipolar RF device, support a full left maze with testing of the electrical block.Unfortunately, this technique needs a bilateral approach, increasing invasiveness.Some authors [3,4] also described AF ablations through a monolateral approach.However, this procedure was performed 'on pump' and on cardioplegic arrest.From these articles, we could conclude that best approach and best lesion set are inversely related.From this point of view, Solinas et al., using a bipolar RF device, did not change this paradigm.In fact, their technique was only in part performed on beating heart but, it was always during the extracorporeal circulation and for a concomitant mitral valve disease, where left atrium was opened.Solinas et al. [1] have not explained the selection criteria of patients.According to the literature, persistent and permanent AF could have a more extended lesion set.In our opinion, this treatment may count almost the mitral isthmus to avoid supra ventricular tachycardia, like atypical flutters.Ideally, surgeons would like to develop a technique easy to perform, monolateral, off-pump, epicardial, with adequate transmural lesion set, and good clinical outcomes.Bipolar RF clamp devices that appear to be most capable of reliably producing transmural lesions are least able to be minimally invasive.Alternative sources of energy could be taken into account to solve this dilemma.Recently, we described a method for AF ablation using high-intensity focused ultrasound (HIFU) energy [5] with promising results.However, it is our opinion that a good selection of the patients should be always taken into account.In fact, even if we performed AF ablation with an HIFU device, we were not able to create a bi-atrial lesion set useful for patients with more severe and advanced states of AF.In conclusion, Solinas et al. plead a case of AF treatment moving toward a simpler and less-invasive procedure.We hope industries will respond by applying the innovative technology to the needs of new instruments capable of retaining the efficacy of the full Cox-maze procedure and really adapted for MIS.