[Artificial graft replacement increases the speed of the pulse wave velocity along the aorta]

We investigated the change in the pulse wave velocity along the aorta after a part of the vessel was replaced by artificial graft in seven patients. Graft-replacement was performed under general or general combined with epidural anesthesia. The velocity measurement was performed in a standard manner before and after the surgical procedure. The replacement by artificial graft consistently increased the pulse wave velocity of which the means +/- SD were 10.4 +/- 2.4 m.s-1 before the surgery, and 13.3 +/- 3.6 m.s-1 after the surgery, amounting a 26.9 per cent increase. The change was statistically significant. The range of this increase was between 8.9% and 45.7%. No changes were observed in various hemodynamic parameters and hematocrits, except the heart rate which increased from 57.4 to 69.1 +/- 9.0 bpm. We conclude that the speed of the pulse wave velocity along the aorta increases markedly by artificial graft replacement. We propose this change is caused by a marked stiffness of the material of the artificial graft. The exact mechanism, however, remains to be elucidated.