Hemodynamic evaluation in patients with superficial temporal artery-middle cerebral artery anastomosis--stable xenon CT-CBF study and acetazolamide.

Sixteen patients with minor completed stroke in the chronic stage underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. The acetazolamide-activated regional cerebral blood flow (rCBF) was measured 20 minutes after the injection using inhalation of stable xenon and computed tomographic scanning (Xes CT-CBF study) pre- and postoperatively. Eleven patients (Group 1) showed immediate improvement in neurological state within a few days of the operation, while five (Group 2) showed no improvements. Preoperative rCBF in the ischemic areas without infarction was 30.8 +/- 3.0 ml/100 gm/min in Group 1 and 53.0 +/- 5.2 ml/100 gm/min in Group 2. Preoperative vasodilatory capacity with acetazolamide in Group 1 was 5.7 +/- 8.6 and significantly increased to 19.8 +/- 4.9 after surgery. In Group 2, pre- and postoperative vasodilatory capacity was 12.7 +/- 3.1 and 14.9 +/- 2.9, respectively, and there was no significant change. These results suggested that minor stroke patients with moderate decrease of affected side rCBF (less than 40 ml/100 gm/min) and with hemodynamic impairment may have the surgical indication for STA-MCA anastomosis.