Current Balloon Devices for Ablation of Atrial Fibrillation

Abstract

Balloon-based catheter ablation is a valuable option for the treatment of atrial fibrillation (AF) because contiguous lesions can be created to achieve pulmonary vein isolation (PVI), and the method is less dependent than traditional ablation methods on the operator's skill and experience. Cryoballoon ablation is used universally worldwide, with its efficacy and safety being comparable to the efficacy and safety of standard radiofrequency ablation, and the procedure can be completed in a relatively short time. Hot balloon ablation was developed in Japan. The balloon maintains its compliance even during the energy delivery, and a large areal ablation lesion is created. Furthermore, the hot balloon system is the only system for which oesophageal cooling is a standard feature. Laser balloon ablation, which is performed under direct endoscopic vision, has proven to be effective and safe for achieving a PVI. The laser balloon system provides an improved field of view and automated circumferential ablation for a rapid and effective PVI. The authors have reviewed the currently available balloon systems as used for AF ablation, i.e., PVI, and have provided detailed insight and perspectives on the currently available cryoballoon and hot balloon technologies, plus laser balloon technology.

Keywords: atrial fibrillation; cryoballoon; hot balloon; laser balloon.

Fig. 1.

Arctic Front cryoballoon (AFCB) system. (A) The improvement in the pulmonary vein (PV) potential recordings by moving the catheter proximally immediately after the start of freezing. The short tip of the fourth-generation AFCB catheter contributes to the improved PV potential recording. (B) The white double-ended arrows show the tip length of the second- and fourth-generation AFCB catheters (13.5 mm vs. 8 mm). Adopted from Medtronic Japan.

Fig. 2.

Hot balloon system. (A) The balloon compliance is maintained during ablation. The temperature of the liquid inside the balloon rises as radiofrequency waves flow from the coil inside the balloon to the anti-pole plate. Conductive heating has a thermal effect on the myocardium. (B) [Upper panel] The results of the computer-aided thermo-fluid analysis. [Lower panel] An additional temperature sensor lies 15 mm from the south pole of the balloon on the catheter shaft. The tissue temperature corresponds to the estimated balloon surface temperature recorded from the temperature probe (upper panel). (C) Fluoroscopic image and intracardiac potentials, internal balloon and surface temperature dynamics during the electrical isolation of the left superior PV, with a TTI of 16 sec and a median balloon surface temperature of 60 °C. PV, pulmonary vein; TTI, time to isolation; PVI, pulmonary vein isolation. Adopted from Toray Inc.

Fig. 3.

Laser balloon system. (A) The third-generation HeartLight X3 system is equipped with a motorized, fully automated circumferential energy delivery system. Laser energy penetrates the endocardium and produces a thermal effect from the mid-myocardium. (B) Fluoroscopic and endoscopic images of a balloon positioned within the left superior pulmonary vein (PV). (C) Endoscopic images obtained with the use of first- and third-generation laser balloon systems. (D) Direct endoscopic visualization of a laser ablation lesion. Adopted form Japan Lifeline.

Fig. 4.

Features of the three currently available balloon ablation systems. CB, cryoballoon; HB, hot balloon; LB, laser balloon; AFCB, Arctic Front cryoballoon; RF, radiofrequency. Adopted from Medtronic Japan, Toray Inc, and Japan Lifeline.