a valveless , single-orifice abdominal aortic counterpulsation device ( aacd ) was implanted retroperitoneally on the abdominal aorta and was pumped continuously , providing aortic diastolic augmentation for 45 +/- 4.9 days in four calves ( group a ) .
C0003484
abdominal aorta
C0003483
aortic