Cerebral microembolization during radiofrequency ablation of lung malignancies.

Three patients underwent radiofrequency (RF) ablation for treatment of malignant lung tumors. During three of the four RF ablation sessions, duplex ultrasound was used to intermittently sample the carotid arteries for the presence of emboli; microemboli were detected in all three patients. Embolization occurred within 1 minute of "roll-off." The rate of embolization ranged from 2 to 50 per minute. No new neurologic defects were found on examination. No cognitive, memory, or behavioral changes were noted by any of the three patients or their spouses. Microemboli to the cerebral circulation occurred during RF ablation of lung tumors. The clinical significance of these emboli is unknown.