Clinical utility of the “balloon lever technique” in the right inferior pulmonary vein cryoballoon ablation

Figures

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  FIGURE 1. Balloon lever technique (BLT). (A) The initial position of the balloon lever. (B) The balloon lever is pressed forward, leading to the downward shift of the balloon, as shown in (D). (C) The initial position of the cryoballoon (CB). (D) The downward shift of the CB that is caused by the forward displacement of the lever, as shown in (B). (E) The model of the left atrium. The achieve catheter is inserted into the inferior branch of the right inferior pulmonary vein (RIPV). The CB is moved forward with the conventional method. A space is observed between the CB and the bottom of the RIPV (white arrowhead). (F) The model of the left atrium. The CB is moved towards the RIPV using the BLT. The CB is pressed to the bottom of the RIPV antrum, leading to the disappearance of the space (white arrowhead).

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  FIGURE 2. Right inferior pulmonary vein (RIPV) cryoballoon (CB) ablation with conventional method and balloon lever technique (BLT) in a representative patient. The achieve catheter is inserted into the inferior branch. (A) Massive leakage of the contrast medium is observed at the inferior site of the RIPV (white arrow). The shape of the RIPV could not be confirmed due to the flushing of the contrast medium. (B) Optimal RIPV occlusion is achieved with the BLT. The CB is shifted downward and pressed to the bottom of the RIPV (white arrow). A selective contrast injection to the RIPV shows contrast retention, and the shape of the RIPV could be discerned (white arrowhead). The optima is positioned in the superior vena cava. An intracardiac echocardiography catheter (ICE) is positioned in the right ventricle. CS, coronary sinus; Eso, esophageal temperature monitoring catheter; RAO, right anterior oblique projection.

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  FIGURE 3. Flowchart summarizing the right inferior pulmonary vein (RIPV) cryoballoon ablation (CBA) and the distribution of the patients. The blue panel indicates the patients showing successful RIPV isolation with the initial conventional CBA. In contrast, the green panels indicate the patients showing RIPV isolation with the balloon lever technique (BLT) CBA. The yellow panels indicate the patients in whom RIPV was not isolated using the hospital protocol.

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  FIGURE 4. Effectiveness of balloon lever technique (BLT) after the ineffective conventional method. (A) Right inferior pulmonary vein (RIPV) isolation rate with BLT for the residual RIPV potentials (RIPVPs) after conventional cryoablation. (B) Rapid cooling rate of BLT in the patients showing slow cooling during conventional cryoablation. (C) Rapid cooling rate of BLT in the patients showing poor occlusion with the conventional method. (D) RIPV isolation rate with BLT after the ineffective conventional method.

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  FIGURE 5. Comparison of the freezing time to −20°C between the initial conventional and the subsequent balloon lever technique (BLT) cryoablations (n = 26).

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  FIGURE 6. Comparisons of the nadir balloon temperature (A), freezing time to −40°C (B), thawing time to 0°C (C) and 20°C (D) between the initial conventional and the subsequent balloon lever technique (BLT) cryoablations (n = 6).