Deep Myocardial Ablation Lesions Can Be Created with a Retractable Needle-Tipped Catheter

• Published in: Pacing and clinical electrophysiology Vol. 27; no. 5; pp. 594 - 599
• Main Authors: SAPP, JOHN LEWIS, COOPER, JOSHUA MORREY, SOEJIMA, KYOKO, SORRELL, TIMOTHY, LOPERA, GUSTAVO, SATTI, SRINIVASA DINAKAR, KOPLAN, BRUCE ANDREW, EPSTEIN, LAURENCE MARK, EDELMAN, ELAZER, ROGERS, CAMPBELL, STEVENSON, WILLIAM GREGORY
• Format: Journal Article
• Language: English
• Published: 350 Main Street , Malden , MA 02148-5018 , USA and 9600 Garsington Road , Oxford OX4 2DQ , UK Blackwell Futura Publishing, Inc 01.05.2004
• Subjects: ablation; Animals; catheter ablation; Catheter Ablation - instrumentation; Equipment Design; Feasibility Studies; Male; Myocardium - pathology; Swine; tachyarrhythmias; ventricles
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/j.1540-8159.2004.00492.x

RF catheter ablation of ventricular tachycardia is sometimes limited by inadequate lesion depth. This study investigated the use of a retractable needle‐tipped catheter to create deep RF lesions in vivo in porcine myocardium. An 8 Fr electrode catheter with an extendable 27‐gauge needle at the tip was modified for RF ablation by embedding a thermocouple and attaching a pin connector. In three swine (32–58 kg) the left ventricle was entered via the femoral artery and endocardial contact was made. The needle was advanced 10 mm and 13 RF applications were made under a controlled temperature (90°C × 120 s). Nine control lesions were made using a standard 4‐mm tip catheter (60°C × 120 s). The lesions were fixed, serially sectioned from the endocardium, digitally imaged, and quantified. Needle ablation lesions were deeper (10.15 ± 0.77 vs 5.67 ± 0.37 mm, P < 0.001) and more likely to be transmural (77 vs 11%, P = 0.008) than control lesions. The volume of control lesions, however, was larger (358.4 ± 56.2 vs 174.7 ± 18.6 mm3, P = 0.002) due to a significantly larger cross‐sectional area at the endocardium (0.548 ± 0.04 vs 0.151 ± 0.01 cm2, P < 0.001). At depths > 6 mm, the needle electrode lesions had a greater cross‐sectional area (0.136 ± 0.01 vs 0.005 ± 0.004 cm2, P < 0.001). Catheter‐based needle ablation is feasible and allows creation of deeper lesions that can be transmural. Although deep, the lesions had a small cross‐sectional area such that precise targeting would be required for success. (PACE 2004; 27:594–599)