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Microwave Catheter Ablation Using a Clinical Prototype System with a Lateral Firing Antenna Design
Author(s) -
LIEM L. BING,
MEAD R. HARDWIN,
SHENASA MOHAMMAD,
CHUN SUNG,
HAYASE MOTOYA,
KERNOFF ROBERT
Publication year - 1998
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1998.tb00128.x
Subject(s) - medicine , catheter ablation , ablation , microwave ablation , microwave , antenna (radio) , catheter , biomedical engineering , radiology , electrical engineering , telecommunications , computer science , engineering
Microwave has been considered a potentially more effective and more versatile form of energy than radiofrequency. Its feasibility has been tested using various prototype systems and catheter designs. This study assessed the safety and efficacy of a clinically‐suitable prototype microwave power supply and catheter system with a lateral‐firing antenna design for atrioventricular (AV) junction ahlation in canines and to correlate with tissue histopathology. The system consisted of a deflectable catheter with a 6‐mm antenna and a thermocouple; and a 2.45‐CHz frequency generator with power, time, and temperature controls. AV junction ablations were performed using 75 W energy for up to 60 seconds. Effective heating was confirmed hy a rise in catheter temperature to 69.3 ± 8.8°C. Complete AV nodal block was accomplished in all canines after an average of 4.1 ± 2.3 applications at 66.8 ± 7.7°C, and persisted after 28 days in all chronic animals. Lesions were consistent with thermal necrosis, were hemispherical to semi linear in shape and have distinct borders. Acute lesions were 3.4 ± 1.5 mm wide, 4.8 ±2.1 long, and 2.0 ± 0.9 deep. Chronic lesions showed typical healing and were smaller in size. Ablations did not cause any transvalvular, vascular or other cardiac structural damage, and no coagulum formation was noted on the antenna or catheter tip. Microwave AV junction ablation using this clinical prototype system specifically designed for it was safe and effective. Lesion's depth was limited to 5 mm with 60‐second heating while its shape corresponded to the antenna's length. Microwave energy may provide greater versatility for producing discrete or linear ablation.