The Annals of Thoracic Surgery, Vol 21, 203-208, Copyright © 1976 by The Society of Thoracic Surgeons
An extravascular left ventricular assist device
I Kiso, CA Baechler, O Hamada, G Mandell, B Hisamichi and A Kantrowitz
The hemodynamic efficacy and prosthesis-vessel interaction of a
pneumatically activated circulatory assist device was investigated in 12
acute and 12 chronic studies in dogs. A polyurethane balloon encased in
Dacron-velour cloth was fastened to the descending thoracic aorta with a
spiral wrapping of Dacron graft material. Diastolic augmentation was
provided by rhythmic inflation and deflation of the balloon. Hemodynamic
results, based on 5 dogs with experimental myocardial ischemia, showed that
left ventricular systolic peak pressure decreased by 8.2 +/- 1.9%, cardiac
output increased by 13.1 +/- 2.8%, and circumflex coronary artery flow rose
by 17.5 +/- 2.5%. In the chronic experiments the prosthesis was
asynchronously but continuously activated from one to sixteen weeks at 74
cycles per minute. Postmortem examination of the implantation site in all
12 dogs showed that necrosis had developed but was limited to the outer
half of the medial layer beneath the pumping chamber and that the aortic
wall was compressed to about 70% of its original thickness. Although the
method described represents a simple form of providing ventricular
assistance, its applicability for long-term circulatory support remains to
be evaluated.
