No shinkei geka. Neurological surgery
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The combined one-stage operations, STA-MCA anastomosis and internal carotid artery (ICA) ligation (or trapping) were carried out in 11 cases (Age): 18-79 yrs, Av.: 45.8 yrs) of ICA aneurysms which were inaccessible for a direct operation because of their locations and sizes. First the STA-MCA anastomosis was performed under general anesthesia. Then the patient was awaken and thereafter under local anesthesia the ICA was temporarily clamped for 30 min. under induced hypotension to check whether any ischemic signs appeared. ⋯ Intra-arterial pressure measurements of the STA and MCA suggested that the one-stage operations of these two procedures are better than the two-stage operations for the patency of the anastomosis because the pressure gradient between the donor and recipient vessels is increased (from 10.3 mmHg to 49.3 mmHg) by this technique. Temporary ICA clamp for 30 min. under induced hypotension in local anesthesia is useful to check whether the one-stage operations can be tolerated or not. EC/IC bypass with an interposed saphenous vein graft is a more beneficial surgical technique than a routine STA-MCA anastomosis, because an immediate and larger amount of bypass flow can be obtained.