抄録
In order to evaluate the efficacy of bypass surgery, the authors analyzed the long-term results of a surgical group in comparison with those of a non-surgical group. In 42 cases in the surgical group, sixty percent of 35 patients who had neurological impairment showed improvement, especially significant improvement of cortical function such as memory disturbance and/or motor aphasia. Throughout the long-term follow-up ischemic reattacks decreased in the surgical group. On the other hand, in the non-surgical group, many patients with hemodynamic compromise suffered reattacks in the follow-up period. Regarding the finding of preoperative CT scan, bypass surgery was more effective on patients with no infarction or with watershed infarction than other types of infarction. In order to check the hemodynamic status, cerebral blood flow (CBF) was measured by 133Xe SPECT, and the Diamox test was added. In the surgical group, most patients showed a significant increase of CBF and improvement of Diamox reactivity in accordance with improvement of neurological symptoms. Although Diamox test is a useful method for evaluating the cerebral perfusion reserve and hemodynamic compromise, in some cases the decreased Diamox reactivity did not invariably reflect hemodynamic compromise. Therefore, cerebral blood volume should be measured by 99mTc-RBC SPECT to select patients for bypass surgery. Consequently, bypass surgery has a beneficial effect on patients with hemodynamic compromise, not only preventing ischemic attacks but also improving memory disturbance.
