DETECTION OF EMBOLIC SIGNALS DURING AND AFTER PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY OF SUBCLAVIAN AND VERTEBRAL ARTERIES USING TRANSCRANIALDOPPLER ULTRASONOGRAPHY

OBJECTIVE: Percutaneous transluminal angioplasty (PTA) is accepted as a safe and effective procedure for the treatment of stenotic arterial lesions of various sites. However, distal embolism may cause serious c omplications in the PTA of cephalic arteries. By monitoring embolic si gnals using transcranial Doppler (TCD) ultrasonography, we speculated regarding the safety and/or risk of PTA for vertebral and subclavian a rtery stenosis. METHODS: Twelve consecutive patients undergoing PTA fo r subclavian and vertebral artery stenosis of atherosclerotic origin w ere studied. All patients were refractory to initial medical treatment and were considered for PTA. During the PTA procedure, all patients w ere heparinized. Before, during, and after PTA, TCD monitoring was per formed to detect embolic signals for 30 minutes at each time. After PT A, anticoagulant and antiplatelet therapies were continued in all pati ents. RESULTS: Before, during, and after PTA, a steady flow signal cou ld be obtained from each vertebral artery monitored using TCD ultrason ography. No embolic signals were detected in any patient before angiop lasty. During angioplasty, one embolic signal was detected immediately after balloon deflation in 1 of 12 patients. Several embolic signals were detected after the procedure in 6 of 12 patients, but thereafter embolic signals became less frequent in number. Three days after angio plasty, embolic signals were not detected in any patient. There were n o serious complications caused by the PTA procedure. CONCLUSION: TCD m onitoring may be a useful modality for detection of microemboli during and after PTA in the posterior circulation. We suspected that subclin ical microemboli are released from the dilated vessels for 3 days afte r vertebral and subclavian PTA and that anticoagulant or antiplatelet therapies may prevent embolic complications after the procedure.