Department of cardiovascular medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Clin Cardiol. 2023 Feb;46(2):126-133. doi: 10.1002/clc.23947. Epub 2022 Nov 20.
Damage to the sinus node (SN) has been described as a potential complication of superior vena cava (SVC) isolation. There have been reports of permanent SN injury requiring pacemaker implantation during isolation of the SVC.
It is safe and effective to isolate SVC with the second-generation 28-mm cryoballoon by using a novel method.
Forty-three patients (including six redo cases) with SVC-related atrial fibrillation (AF) from a consecutive series of 650 patients who underwent cryoballoon ablation were included. After pulmonary vein isolation was achieved, if the SVC trigger was identified, the SVC was electrically isolated using the cryoballoon. First, the cryoballoon was inflated in the right atrium (RA) and advanced towards the SVC-RA junction. After total occlusion was confirmed by dye injection with total retention of contrast in the SVC, the SVC-RA junction was determined. Next, the cryoballoon was deflated, advanced into SVC, then reinflated, and pulled back gently. The equatorial band of the cryoballoon was then set slightly (4.32 ± 0.71 mm) above the SVC-RA junction for isolation of the SVC.
Real-time SVC potential was observed in all patients during ablation. The mean time to isolation was 24.5 ± 10.7 s. The SVC was successfully isolated in all patients. The mean number of freeze cycles was 2.5 ± 1.4 per patient, and the mean ablation time was 99.8 ± 22.7 s. A transient phrenic nerve (PN) injury occurred in one patient (2.33%). There were no SN injuries. Freedom from AF rates at 6 and 12 months was 97.7% and 93.0%, respectively.
This novel method for SVC isolation using the cryoballoon is safe and feasible when the SVC driver during AF is determined and could avoid SN injury. PN function should still be carefully monitored during an SVC isolation procedure.
窦房结（SN）损伤已被描述为上腔静脉（SVC）隔离的潜在并发症。有报道称，在 SVC 隔离过程中，由于 SN 永久性损伤需要植入起搏器。
使用一种新方法，通过第二代 28mm 冷冻球囊安全有效地隔离 SVC。
连续 650 例接受冷冻球囊消融的患者中，有 43 例（包括 6 例再手术）患者因 SVC 相关房颤（AF）而纳入研究。在实现肺静脉隔离后，如果识别到 SVC 触发，则使用冷冻球囊对 SVC 进行电隔离。首先，将冷冻球囊充气至右心房（RA），并向 SVC-RA 交界处推进。当用染料注射完全闭塞并确认 SVC 内的造影剂完全保留后，确定 SVC-RA 交界处。接下来，将冷冻球囊放气，推进 SVC，然后再充气并轻轻拉回。然后将冷冻球囊赤道带略微（4.32±0.71mm）置于 SVC-RA 交界处上方，以隔离 SVC。
所有患者在消融过程中均观察到实时 SVC 电位。隔离平均时间为 24.5±10.7s。所有患者均成功隔离 SVC。每个患者的冷冻循环次数平均为 2.5±1.4 次，平均消融时间为 99.8±22.7s。1 例（2.33%）患者出现短暂性膈神经（PN）损伤。无 SN 损伤。6 个月和 12 个月时无 AF 发生率分别为 97.7%和 93.0%。
当确定 AF 期间 SVC 驱动因素时，使用冷冻球囊进行这种新的 SVC 隔离方法是安全可行的，并且可以避免 SN 损伤。在 SVC 隔离过程中，仍应仔细监测 PN 功能。
