Lung radiofrequency ablation with and without bronchial occlusion: experimental study in porcine lungs.
OBJECTIVE
This study was undertaken to compare the thermal lesion volumes in normal pig lungs when radiofrequency (RF) ablation is performed with and without airway occlusion.


METHODS
RF ablation was performed in six pigs. A straight 17-gauge internally cooled-tip electrode with a 2-cm exposed tip was inserted into the center of the lower lobe of the lung under biplane fluoroscopic guidance. In each animal, RF ablation was performed for 12 minutes with balloon occlusion of the main bronchus in one lung and without balloon occlusion in the contralateral lung. The tissue temperature around the electrode tip was measured immediately after RF application. The volumes of the thermal lesions were compared by histologic examination of the groups of lungs ablated with and without airway occlusion.


RESULTS
Tissue temperature was significantly higher in the bronchial occlusion group than in the group with normal ventilation (51 degrees C +/- 7 vs. 44 degrees C +/- 2; P < .05). RF ablation with bronchial occlusion resulted in the creation of a significantly greater thermal lesion volume compared with RF ablation with normal ventilation (6,535 mm(3) +/- 1,114 vs 3,368 mm(3) +/- 676; P < .03).


CONCLUSIONS
Prevention of ventilation in the normal swine lung via bronchial balloon occlusion during RF ablation increases the thermal ablation lesion volume, suggesting that active ventilation is a significant cause of in vivo heat loss.
Oshima
Fumiyoshi
F
Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
Yamakado
Koichiro
K
Akeboshi
Masao
M
Takaki
Haruyuki
H
Nakatsuka
Atsuhiro
A
Makita
Masashi
M
Takeda
Kan
K
D000402:Airway Obstruction; D000818:Animals; D001980:Bronchi / Q000528:radiation effects*; D017115:Catheter Ablation; D005260:Female; D005471:Fluoroscopy; D008168:Lung / Q000528:radiation effects*; D015641:Radiography, Interventional; D013552:Swine; D014057:Tomography, X-Ray Computed