Catheter Ablation -> Atrial Fibrillation & Atrial Flutter: -> Experimental methods D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-157 - Radiofrequency Ablation Using A Novel Insulated-tip Catheter Design Can Create Uniform Lesions Comparable In Size To Conventional Irrigated Ablation Catheters, While Requiring A Fraction Of The Energy And Irrigation Flow Rate (ID 473)


Background: With conventional RF ablation (RFA) catheters, >90% of energy dissipates into bloodstream/surrounding tissue. We hypothesized that a novel catheter design (Fig 1) with an insulated tip capable of blocking the RF path may focus >80% of the energy into targeted tissue, while requiring reduced power and irrigation flow rates (IFR).
Objective: This study evaluated the safety and efficacy of RFA using a novel ablation catheter (Sirona Medical Technologies, SMT) versus a ThermoCool (TC) catheter, in vivo and ex vivo.
Methods: RF applications were delivered over live porcine thigh muscle preparations superfused with heparinized saline (in vivo) as well as sections of porcine myocardium inside a tissue bath (ex vivo). In total, 97 unipolar RF applications were delivered for 30 or 60 s using SMT at 6, 8, 10 or 12 W at 2 mL/min versus 34 applications with TC at 30 W at 30 mL/min. RF parameters and lesions were analyzed.
Results: Compared to TC (Fig 2), RF lesions created with SMT were more uniform and homogeneous (Fig 3). Moreover, RFA using SMT at 10 W and TC at 30 W resulted in comparable lesion sizes, including a max diameter of 8.3 ± 1.3 mm (SMT) Vs 8.1 ± 1.4 mm (TC), depth of 6.4 ± 1.2 mm (SMT) Vs 6.1 ± 1.5 mm (TC) and volume of 238 ± 89 mm3 (SMT) Vs 220 ± 100 mm3 (TC). There was no tissue cavitation/charring noted with SMT. However, there was 1 case of tissue cavitation and 1 case of charring associated with TC. There were also 3 steam pops observed with TC, but none with SMT.
Conclusion: RFA using the novel, insulated-tip SMT catheter can create uniform lesions comparable in size to those generated with TC, while requiring a fraction of the energy and IFR. This may have clinical implications with respect to efficacy and safety.