Yasuhiro Yoshiga1, Takeshi Okamoto2, Akihiko Shimizu3, Takeshi Ueyama4, Makoto Ono4, Takahiro Mito4, Masakazu Fukuda4, Hironori Ishiguchi4, Takuya Omuro3, Shigeki Kobayashi4, Atsushi Goto2, Jun Nishikawa5, Isao Sakaida2, Masafumi Yano4. 1. Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan. Electronic address: yoshiga@yamaguchi-u.ac.jp. 2. Department of Gastroenterology and Hepatology, Yamaguchi University Graduate School of Medicine, Ube, Japan. 3. Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube, Japan. 4. Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, Ube, Japan. 5. Department of Laboratory Science, Yamaguchi University Graduate School of Medicine, Ube, Japan.
Abstract
BACKGROUND: Second-generation cryoballoon (2G-CB) ablation is highly effective for achieving pulmonary vein isolation (PVI) with a promising clinical outcome. However, the ideal freezing strategy for preventing gastroesophageal excessive transmural injury (ETI) remains under debate. This study aimed to clarify the correlation between gastroesophageal ETI and a bonus-freeze protocol after PVI using 2G-CBs. METHOD: This study included 100 patients who underwent PVI using 2G-CB followed by an endoscopic examination. The freeze-cycle duration was set at 180s. In the first 33 patients a 120s bonus-freeze was applied after successful PVI (bonus group), while in the following 67 the bonus freeze was omitted (non-bonus group). Early freezing interruption was performed when the esophageal temperature reached 25°C. Gastroesophageal ETI was defined as any injury that resulted from the PVI, including esophageal damage or periesophageal nerve injury. RESULTS: Gastroesophageal ETIs were observed in 9 (27.3%) and 6 (9.0%) patients and were all asymptomatic, esophageal damage in 3 and 0, and periesophageal nerve injury in the remaining 6 and 6 in the bonus group and non-bonus group, respectively (p=0.033). In the multivariate analysis, the bonus freeze protocol (odds ratio 3.527; 95% confidence interval 1.110-11.208; p=0.033) was the sole independent predictor of gastroesophageal ETI. During a one-year follow-up 26 of 33 bonus group patients (78.8%) and 52 of 67 (77.6%) non-bonus group patients remained in stable sinus rhythm without any differences between the groups. CONCLUSIONS: In the patients with a bonus-freeze protocol using the 2G-CB, gastroesophageal ETIs were detected more often than in those with the non-bonus freeze protocol. In contrast, freedom from atrial fibrillation after the 2G-CB based PVI was comparable when applying either a bonus or non-bonus freeze protocol.
BACKGROUND: Second-generation cryoballoon (2G-CB) ablation is highly effective for achieving pulmonary vein isolation (PVI) with a promising clinical outcome. However, the ideal freezing strategy for preventing gastroesophageal excessive transmural injury (ETI) remains under debate. This study aimed to clarify the correlation between gastroesophageal ETI and a bonus-freeze protocol after PVI using 2G-CBs. METHOD: This study included 100 patients who underwent PVI using 2G-CB followed by an endoscopic examination. The freeze-cycle duration was set at 180s. In the first 33 patients a 120s bonus-freeze was applied after successful PVI (bonus group), while in the following 67 the bonus freeze was omitted (non-bonus group). Early freezing interruption was performed when the esophageal temperature reached 25°C. Gastroesophageal ETI was defined as any injury that resulted from the PVI, including esophageal damage or periesophageal nerve injury. RESULTS: Gastroesophageal ETIs were observed in 9 (27.3%) and 6 (9.0%) patients and were all asymptomatic, esophageal damage in 3 and 0, and periesophageal nerve injury in the remaining 6 and 6 in the bonus group and non-bonus group, respectively (p=0.033). In the multivariate analysis, the bonus freeze protocol (odds ratio 3.527; 95% confidence interval 1.110-11.208; p=0.033) was the sole independent predictor of gastroesophageal ETI. During a one-year follow-up 26 of 33 bonus group patients (78.8%) and 52 of 67 (77.6%) non-bonus group patients remained in stable sinus rhythm without any differences between the groups. CONCLUSIONS: In the patients with a bonus-freeze protocol using the 2G-CB, gastroesophageal ETIs were detected more often than in those with the non-bonus freeze protocol. In contrast, freedom from atrial fibrillation after the 2G-CB based PVI was comparable when applying either a bonus or non-bonus freeze protocol.