Cortical Arterial Pressure and Anastomotic Blood Flow Measurements during STA-MCA Anastomosi

Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis was performed in 72 patients with internal carotid artery (ICA) occlusion (22), ICA stenosis (25), middle cerebral artery (MCA) occlusion (eight), MCA stenosis (eight), or moyamoya disease (nine). Cortical arterial pressure (CAP) was obtained as a back pressure by temporary occlusion of the STA trunk after STA-MCA anastomosis. Anastomotic blood flow (AF) was measured with an electromagnetic flow meter applied to the STA. Systemic arterial blood pressure (SABP) was measured at the radial artery. The size of the STA was measured at the anastomotic site by the use of preoperative angiography. The mean CAP and AF were 45 mmHg and 30 ml/min in ICA occlusion, 83 mmHg and 20 ml/min in ICA stenosis, 36 mmHg and 32 ml/min in MCA occlusion, 72 mmHg and 21 ml/min in MCA stenosis, and 31 mmHg and 31 ml/min in moyamoya disease. The product of perfusion pressure (SABP-CAP) and square of the internal diameter of the STA was significantly correlated with AF. The results of this study suggest that a CAP of 20 to 30 mmHg may be critical in occlusive cerebrovascular diseases. Furthermore, CAP and STA size appear to be the two most important indicators of blood supply through STA-MCA anastomoses.