One-Way Ablation With a Cryoballoon on the Left Atrium Roof Using a Novel Button-on Technique: A Retrospective Study.

Introduction: Cryoballoon ablation (CryoBA) of the left atrium (LA) roof is usually performed via Achieve catheter anchoring (Medtronic Inc., Minneapolis, MN, USA) of the left superior pulmonary vein (LSPV) and right superior pulmonary vein (RSPV) (two-way CryoBA). The nadir temperature during anchoring of the RSPV is cooler than that during anchoring of the LSPV. Creation of the LA roof line using CryoBA with only an Achieve catheter and sheath bending is difficult. Therefore, we developed a new technique using a push button (Button-on Technique) to stabilize a cryoballoon (CB) on the LA roof and performed LA roof ablation by anchoring only the RSPV (one-way CryoBA). This study aimed to determine the effect of one-way CryoBA and two-way CryoBA on the LA roof.

Methods and results: This retrospective study included 80 patients with persistent atrial fibrillation treated at our hospital between May 2019 and 2021 (one-way CryoBA group, 40 patients; two-way CryoBA group, 40 patients). CryoBA on the LA roof and pulmonary vein isolation were performed using a 28-mm second-generation CB for 180 s during each application. Nadir temperatures and gaps on the LA roof during the first pass were compared between the one-way CryoBA and two-way CryoBA groups. Nadir temperatures during one-way CryoBA from the middle to the left side of the LA roof were significantly decreased compared with those during two-way CryoBA (p < 0.01). Touch-up ablations of the LA roof after the first pass were performed in 1 of 40 patients (2.5%) and in 6 of 40 patients (15%) of the one-way CryoBA and two-way CryoBA groups, respectively, suggesting the presence of significantly fewer gaps in the one-way CryoBA group than in the two-way CryoBA group (p = 0.038).

Conclusion: One-way CryoBA with the Button-on Technique can make nadir temperatures on the LA roof from the middle to the left side cooler compared with two-way CryoBA, causing fewer gaps on the LA roof during the first pass.