Invited Commentary

Abstract

This very insightful work from the St. Louis group [1Watanabe Y. Weimar T. Kazui T. Lee U. Schuessler R.B. Damiano Jr., R.J. Epicardial ablation performance of a novel radiofrequency device on the beating heart in pigs.Ann Thorac Surg. 2014; 97: 673-678Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar] deals with one of the most stimulating issues in modern ablation surgery: how to perform a complete Cox maze epicardially, on the beating heart.The missing piece is how to perform connecting lines in unclampable areas, like between the left and the right pulmonary veins, between the venae cavae and toward the mitral and the tricuspid annulus. Microwave, unipolar radiofrequency, and ultrasound have been tried for this goal, but failed. The Isolator Transpolar (AtriCure, Inc) is the third iteration of an epicardial linear device based on linear ablation with nonclamping bipolar radiofrequency. The first transpolar dry pen was apparently highly effective, but not very suitable for the creation of long continuous lines. The Coolrail (Atricure, Inc), the 3-cm long cooled transpolar radiofrequency device, was more ductile but way less effective on the atrial tissue. This dry linear device seems to catch up consistently on the effectiveness side but at the price of a quite concerning 10% of perforation due to steam popping while performing an ablation line on the beating swine heart. Popping is a consequence of tissue overheating and is particularly worrisome when considering that, in the modern era of epicardial atrial fibrillation surgery, all these devices are meant to be used through ports, in a close chest condition.Another very concerning aspect of these devices is that overheating of the handpiece might predispose to collateral damage. So all sorts of complications that were basically extinguished after the advent of clamping bipolar radiofrequency, thanks to the virtual absence of thermal spread intrinsic to clamping devices, might actually return to be actual with nonclamping tools. This requires surgical skill, experience, and consideration on behalf of the surgeon delivering the treatment.On the other side, like its predecessors, transpolar radiofrequency falls short of creating impeccable epicardial linear connecting lines when deployed epicardially on the beating heart. Only 80% of the tested, quite short, ablation lines resulted actually continuously transmural in the reported experimental setting. This very insightful work from the St. Louis group [1Watanabe Y. Weimar T. Kazui T. Lee U. Schuessler R.B. Damiano Jr., R.J. Epicardial ablation performance of a novel radiofrequency device on the beating heart in pigs.Ann Thorac Surg. 2014; 97: 673-678Abstract Full Text Full Text PDF PubMed Scopus (9) Google Scholar] deals with one of the most stimulating issues in modern ablation surgery: how to perform a complete Cox maze epicardially, on the beating heart. The missing piece is how to perform connecting lines in unclampable areas, like between the left and the right pulmonary veins, between the venae cavae and toward the mitral and the tricuspid annulus. Microwave, unipolar radiofrequency, and ultrasound have been tried for this goal, but failed. The Isolator Transpolar (AtriCure, Inc) is the third iteration of an epicardial linear device based on linear ablation with nonclamping bipolar radiofrequency. The first transpolar dry pen was apparently highly effective, but not very suitable for the creation of long continuous lines. The Coolrail (Atricure, Inc), the 3-cm long cooled transpolar radiofrequency device, was more ductile but way less effective on the atrial tissue. This dry linear device seems to catch up consistently on the effectiveness side but at the price of a quite concerning 10% of perforation due to steam popping while performing an ablation line on the beating swine heart. Popping is a consequence of tissue overheating and is particularly worrisome when considering that, in the modern era of epicardial atrial fibrillation surgery, all these devices are meant to be used through ports, in a close chest condition. Another very concerning aspect of these devices is that overheating of the handpiece might predispose to collateral damage. So all sorts of complications that were basically extinguished after the advent of clamping bipolar radiofrequency, thanks to the virtual absence of thermal spread intrinsic to clamping devices, might actually return to be actual with nonclamping tools. This requires surgical skill, experience, and consideration on behalf of the surgeon delivering the treatment. On the other side, like its predecessors, transpolar radiofrequency falls short of creating impeccable epicardial linear connecting lines when deployed epicardially on the beating heart. Only 80% of the tested, quite short, ablation lines resulted actually continuously transmural in the reported experimental setting. Epicardial Ablation Performance of a Novel Radiofrequency Device on the Beating Heart in PigsThe Annals of Thoracic SurgeryVol. 97Issue 2PreviewOnly bipolar clamps create reliable transmural lesions on the beating heart. This study evaluated the performance of a new radiofrequency (RF) device on the beating heart in an acute porcine model. Full-Text PDF