Aprotinin use in patients with dialysis-dependent renal failure undergoing cardiac operations ☆ ☆☆ ★ ★★ ♢ ♢♢

closure technique. Histologically, it was proved in these patients that the cancer affected only the external layer of the aortic wall. CT was a feasible means of judging whether malignant tumor had invaded the aorta by observing the motion of the tumors along the aortic wall. This method could be used for either purpose-to discriminate T4 tumors from others as a contraindication for resection or to devise a strategy for concomitant resection of the aorta. Provided an invaded portion of the aorta, which is in contact with the immobile surface of a tumor, has been revealed clearly before the operation, a circulatory bypass and prosthesis required for resection and replacement of the wall can be arranged appropriately. In our seven cases, we took advantage of the new imaging modality in this way. In our series, one tumor in contact with the distal arch was erroneously judged to be invasive. The most likely reason for this misdiagnosis was that the tumor was located on the distal arch near the pulmonary hilus and thus showed barely detectable upward and downward motion during breathing. For the same reason, a noninvasive tumor located on the diaphragm near the pulmonary ligament might be judged invasive by mistake. To avoid such misdiagnoses of pulmonary tumors located on the distal arch or diaphragm, the investigator should use the heartbeat mode as well as the breathing mode for more accurate evaluation, rather than using the breathing mode alone. It is still difficult to discriminate between invasion and fibrous adhesion. We believe that cine CT should reveal malignant adhesion distinctly, because such invasion shows tougher attachment with less mobility than simple fibrous adhesion. A study including more patients will be required to address this issue.