New Polish prototypes of 4- and 8-mm-tip nonirrigated radiofrequency ablation catheters: an in vitro study

Effectiveness of lesion formation during radiofrequency (RF) catheter ablation can be assessed using in vitro or in vivo animal models.

In this in vitro study, we aimed to compare the prototypes of the first Polish RF ablation catheters with common commercially available catheters from other manufacturers.

Samples of the porcine left ventricle were subject to temperature-controlled ablation (50 W / 50 oC / 60 s), using 4- and 8-mm -tip nonirrigated ablation catheters (commercial ones as well as new prototypes). The parameters of RF delivery were collected during energy applications. Subsequently, lesion dimensions were measured and compared between catheters.

Initial impedance and impedance drop during energy delivery differed significantly between catheters (both those with 4-mm and 8-mm tip electrodes). The maximum temperature was similar for 4-mm -tip catheters (P = 0.26), while it differed for 8-mm -tip ones (P <0.001). No significant differences between catheters were noted for lesion volume. The 8-mm -tip prototypes created lesions of greater depth (mean [SD], 5.8 [0.4] mm vs 4.7 [0.4] mm; P <0.001) and volume (mean [interquartile range], 239.4 [217.9-255.5] mm3 vs 173.7 [156.1-186.4] mm3; P <0.001) than those with a 4-mm tip electrode.

Our study showed that RF ablation catheters with the same length of the tip electrode created lesions of similar volume, irrespective of the manufacturer and despite showing distinct physical parameters during energy applications. The Polish catheter prototypes showed similar performance as commercially available devices. Finally, 8-mm -tip prototypes produced lesions of greater depth and volume than those with a 4-mm tip electrode.