Left heart bypass or arterial bypass using a centrifugal pump (Bio-pump bypass) with a H-PSD shunt tube was performed as an auxiliary technique for the treatment of descending thoracic aorta in 13 cases. Hemodynamic differences during aortic clamp were compared between cases using Bio-pump bypass and 4 cases of axillo-femoral temporary bypass which were carried out in the first term. Furthermore, in Bio-pump bypass cases, the bypass route was investigated from the point of view of operative complications in relation to bypass technique. Peripheral blood pressure and urinary output during aortic clamp were significantly increased in the Bio-pump bypass group. Those results indicated that the Bio-pump bypass was useful as an auxiliary technique especially for high risk patients with low renal function. In particular, left heart bypass was a beneficial technique which was not affected by modality or region of disorder in the descending thoracic aorta. However, this technique should be selected carefully for patients with cardiac disease, for instance severe left ventricular hypertrophy, because two cases of operative complications consisting of pericardial effusion related to the bypass technique were experienced in this study.