Open-irrigated laser catheter ablation: influence of catheter–tissue contact force on lesion formation

• Published in: Journal of interventional cardiac electrophysiology Vol. 42; no. 2; pp. 77 - 81
• Main Authors: Sagerer-Gerhardt, Michaela, Weber, Helmut P.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.03.2015; Springer Nature B.V
• Subjects: Animals; Cardiology; Catheter Ablation - adverse effects; Catheter Ablation - instrumentation; Catheter Ablation - methods; Cattle; Heart Ventricles - surgery; Laser Therapy - adverse effects; Laser Therapy - instrumentation; Laser Therapy - methods; Lasers, Solid-State - therapeutic use; Medicine; Medicine & Public Health; Models, Animal; Myocardium - pathology; Pressure; Sensitivity and Specificity; Therapeutic Irrigation; Thrombosis - etiology; Thrombosis - pathology; Catheter–tissue contact force; Open-irrigated laser catheter; Catheter ablation; Laser
• ISSN: 1383-875X; 1572-8595
• DOI: 10.1007/s10840-015-9977-4

Purpose Catheter–tissue contact force (CF) is a major determinant for radiofrequency (RF) ablation lesion size and quality. We sought to test the influence of catheter CF on lesion formation by using an open-irrigated electrode-laser mapping and ablation (ELMA) catheter. Methods With the ELMA catheter in a stable vertical position, continuous wave 1064 nm laser impacts at 15 W (9.5 W/mm 2 ), 30 s (285 J/mm 2 ), irrigation flow 30 mL/min, were aimed at the endocardial surface of bovine myocardium in heparinized stagnant blood (ACT >350 s) at room temperature (18 °C). Lesions were produced with CFs of 100 g, 10 g, in contact but without pressure, with the catheter tip 2.0 mm, and 5.0 mm away ( n  = 10, each). Lesions were evaluated morphometrically and were compared by the unpaired t tests. Results There were no significant differences between volumes of lesions achieved with catheter–tissue CF of 100 g, 10 g, and in contact without pressure: 297 ± 56.0 vs . 300 ± 39 vs . 320 ± 24, respectively ( p  > 0.05). However, volumes of lesions produced at a distance of 2 mm (95 ± 14 mm 3 ) were significantly smaller ( p  < 0.0001), whereas at a distance of 5.0 mm, no lesions were produced. No steam-pop with crater or thrombus formation occurred. Conclusions By using an open-irrigated ELMA catheter, catheter–tissue CF is not a determinant for laser ablation lesion size and quality. Maximum sizes of lesions can be achieved with the catheter in intimate endocardial contact without pressure. However, lesions can be produced also at a catheter–tissue distance of 2.0 mm. Noticeably, there is no thrombus formation during laser application with the free floating ELMA catheter in the stagnant blood.