We investigate the safety and/or risk of PTA for vertebral and subclavian artery stenosis by monitoring embolic signals using transcranial Doppler (TCD) ultrasonography. Twelve consecutive patients undergoing PTA for subclavian and vertebral artery stenosis of atherosclerotic origin were studied. Before, during and after PTA, TCD monitoring was performed to detect embolic signals for 30 minutes at each time. No embolic signals were detected in any patient before angioplasty. During angioplasty, one embolic signal was detected immediately after balloon deflation in one of 12 patients. Several embolic signals were detected after the procedure in six of 12 patients, but thereafter embolic signals became less frequent in number. Three days after angioplasty, embolic signals were not detected in any patient. TCD monitoring could be a useful modality for detection of microemboli during and after PTA in the posterior circulation. Our present study suspected that subclinical microemboli are released from the dilated vessels for three days after vertebral and subclavian PTA and anticoagulant or antiplatelet therapies may prevent embolic complications after the procedure.
