Our group is developing an artificial lung as a bridge to transplant. We ev
aluated the sheep pulmonary artery (PA) for the presence or absence of a se
ptum, which may increase PA resistance and affect artificial lung flow. We
also measured the PA size to determine whether it is a suitable conduit for
artificial lung implantation using a PA-PA shunt. Adult Suffolk ewes in tw
o groups were studied. Group 1 consisted of animals (n = 12, 30-43 kg) prep
ared for thoracotomy. Group 2 (n = 21, 30-43 kg) consisted of postmortem di
ssections. In both groups, the length and girth of the PA was measured. The
heart and lungs were removed on all postmortem animals (group 2), the duct
us arteriosum was crosscut, and the common PA was incised. The average leng
th of the PA in live animals was 5.5 cm and the average diameter was 2.2 cm
. The average length of the PA in postmortem animals was 4.8 cm and the ave
rage diameter was 2.0 cm. All pulmonary arteries were aseptate, and the lig
amentum arteriosum in each PA was not patent. We conclude that the PA is no
t a source of increased resistance and is a suitable conduit for artificial
lung implantation in the PA-PA configuration.