The evaluation of STA-MCA anastomosis by observation of rCBF alterations

The evaluation of STA-MCA anastomosis in ischemic cerebrovascular disease was studied, with special reference to alterations in the rCBF after operation, using single-photon-emission CT. After the operation, the rCBF was not increased in 15 cases, but it was increased significantly in 11 cases, mainly at the anastomotic site. In only 3 cases was the rCBF increased globally, including the deep area of the affected side and also the healthy hemisphere. rCBF study during STA (bypass artery) compression revealed that the blood flow via the bypass artery was significantly increased, mainly at the anastomotic site, after the operation. In some cases, the impairment of the CO2 reactivity and the autoregulation of cerebral vessels were somewhat improved after the operation. These findings probably indicate that the improvement of rCBF by STA-MCA anastomosis has a beneficial effect on the tissue function of the ischemic brain. (author)