[Adjunctive methods for surgery of descending thoracic aortic aneurysm].

During the last 6 years, we employed partial extracorporeal circulation (PEC) in 7 cases and left heart bypass (LHB) in 9 cases as adjunctive methods for surgery of descending thoracic aortic aneurysm. During the aortic clamping, systemic heparinization was performed to keep an ACT more than 400 seconds in a PEC group, while it was kept from 200 to 250 seconds in LHB group. The bypass flow was controlled to maintain the distal arterial pressure over 50 mmHg in both groups. Hemodynamics during the aortic clamping were stable in both groups and significant differences were not found between them. However, ventricular fibrillation occurred in one case of LHB group, who suffered from coronary artery disease, and required subsequent PEC to maintain systemic circulation. Both PEC and LHB provided adequate intraoperative hemodynamics and postoperative serum biochemistries. But we preferred to adopt PEC to maintain the diatal perfusion in cases with heart disease, who are likely to develop circulatory deterioration under the aortic clamping.