In Vivo Tissue Temperature Characteristics of Contact Force Catheter With a Mesh‐Shaped Irrigation Tip: A Porcine Study
Masanaru Sawada, Naoto Otsuka, Koichi Nagashima, Ryuta Watanabe, Yuji Wakamatsu, Satoshi Hayashida, Shu Hirata, Moyuru Hirata, Sayaka Kurokawa, Yasuo Okumura, Kenta Uto, Hiroyuki Hao, Rie Takahashi, Yoshiki TaniguchiABSTRACT
Background
Neither the actual in vivo tissue temperatures reached with a novel contact force sensing catheter with a mesh‐shaped irrigation tip (TactiFlex SE, Abbott) nor the safety profile has been elucidated.
Methods
In a porcine model (n = 8), thermocouples were implanted epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava following a right thoracotomy. After chest closure, endocardial ablation was conducted near the thermocouples under fluoroscopic guidance. We compared tissue temperatures during 50 W/13‐s high‐power short‐duration (HPSD) and 30 W/30‐s standard ablation.
Results
No steam pops were observed in 34 HPSD and 35 standard ablation applications. Tmax (maximum tissue temperature when the thermocouple was located ≤5 mm from the catheter tip) was modestly higher in HPSD compared to standard ablation (60.1°C ± 12.4°C vs. 57.8°C ± 12.9°C; p = 0.46). The peak tissue temperature correlated inversely with the catheter tip‐to‐thermocouple distance (HPSD: r = −0.40; standard: r = −0.57). Lethal temperatures (≥50°C) were reached faster with HPSD (6.5 ± 3.2 s vs. 10.3 ± 8.6 s; p = 0.04) and the distance from the catheter tip achieving a lethal tissue temperature ≥50°C (indicative of the lesion depth) was slightly shallower with HPSD (4.2 and 4.8 mm, respectively). The esophageal injury occurred superficially in both settings (0.98 ± 0.22 mm vs. 1.16 ± 0.18 mm; p = 0.29).
Conclusions
HPSD ablation produced a modestly higher and more rapid increase in the tissue temperature around the veno‐atrial junction with a shorter catheter tip‐to‐thermocouple distance required to reach lethal temperatures. This data contributes to understanding effective lesion creation and collateral injury prevention with the TactiFlex catheter.