title: Temperature-controlled cooled-tip radiofrequency linear ablation of the atria guided by a realtime position management system.
abstract: Due to the difficulty in producing a transmural linear lesion and the possibility of complications such as thrombus formation leading to thromboembolism, the catheter-based maze procedure remains problematic. We tested, in pigs, the possibility of using a temperature-controlled cooled-tip radiofrequency (RF) ablation system together with a realtime position management (RPM) system to create a transmural linear lesion uncomplicated by thrombus formation.Nine pigs underwent insertion of two electrode catheters (each with two ultrasound electrodes), one into the coronary sinus (CS) and one into the right ventricular apex (references for ultrasound-based non-fluoroscopic three-dimensional mapping). A cooled-tip catheter (with two ultrasound electrodes) was introduced into the right atrium. Linear right atrial ablation was performed with a custom radiofrequency (RF) generator. The catheter was perfused with 0.66 mL/second of saline. RF was delivered for 60 seconds at a target temperature of 40°C. A linear ablation line was created between the superior vena cava and inferior vena cava. Three-dimensional isochronal maps were created during CS pacing before and after ablation. In 4 of the 9 pigs, a transmural linear ablation line was confirmed by three-dimensional mapping and postmortem macroscopic examination. No endocardial thrombus formation was noted. Temperature-controlled cooled-tip RF linear ablation guided by an RPM system appears to have potential for creating linear lesions in the atria. Further studies are needed to determine whether such an ablation technique and the parameters used will facilitate successful completion of the catheter-based maze procedure.
authors.affiliation: Division of Cardiology, Department of Medicine, Nihon University School of Medicine, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Nuo
authors.initials: N
authors.lastname: Min
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Okumura
authors.forename: Kimie
authors.initials: K
authors.lastname: Ohkubo
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Kofune
authors.forename: Sonoko
authors.initials: S
authors.lastname: Ashino
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kasamaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hirayama
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000601:surgery; D006348:Cardiac Surgical Procedures / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D003080:Cold Temperature; D004195:Disease Models, Animal; D004566:Electrodes; D006325:Heart Atria / Q000473:pathology / Q000601:surgery*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D013552:Swine; D016896:Treatment Outcome