Operative procedure. A, B. The ascending aorta was transected immediately proximal to the orifice of the innominate artery. The diameter of the ascending aorta was 30 mm. A 10 cm × 10 cm sheet of equine pericardiaum was prepared, and after suturing it to the posterior side of the transected aorta, it was rolled up by continuous suturing from posterior to anterior. C. When the corners of the pericardium met, the suture was tied, and the same thread was used to stitch the two sides of the pericardium continuously to form a cylinder. D. The proximal ascending aorta was transected obliquely, and after trimming the pericardial sheet, a beveled proximal anastomosis was created.