Transcranial Doppler ultrasonography (TCD) has been widely used for assessment of cerebrovascular diseases. We studied the correlation of single photon emission computed tomography (SPECT) and TCD during pre- and post-superficial temporal artery (STA) -middle cerebral artery (MCA) bypass surgery. The patients were seven males (mean age : 63 (57-70) yrs) with occlusion of the internal carotid artery (ICA) undergoing STA-MCA bypass surgery. Two of the patients had bilateral occlusion of the ICA. Mean flow velocity (MFV) and pulsatility index (PI) of the MCA and STA were measured using a TC2-64 and a Transscan. Cerebrovascular reserve capacity was studied using SPECT with Diamox challenge. After bypass surgery, STA-MFV increased and STA-PI decreased on TCD in all subjects. In five of them, STA-MFV increased to more than 30 cm/sec. SPECT studies showed improvement of the cerebrovascular reserve capacity in all patients.
Thus, TCD study of STA is useful for evaluating the effect of EC-IC bypass surgery in patients with occlusion of the ICA.
