Anatomic study of the pulmonary artery as a conduit for an artificial lung

Our group is developing an artificial lung (AL) as a bridge to recovery or transplant. Utilizing a pulmonary artery (PA)-to-PA or PA-to-left atrial (LA) shunt, any anatomic variant to the common PA will affect AL flow. We evaluated the sheep PA for the presence or absence of a septum or other anatomic variant, which may divert or increase resistance to PA blood flow. Adult Suffolk ewes (N=21,30-43 kg) were sedated and euthanized. The heart and lungs were removed en bloc through a median sternotomy. The common PA was isolated, beginning at the sinus of Valsalva, and ending 2 cm past the primary bifurcation. The ligamentum arteriosum was identified and checked for patency. The PA was incised from the sinus of Valsalva to the terminus of the left and right pulmonary arteries. The circumference of the common PA midway between the sinus of Valsalva and the primary bifurcation, and the length of the common PA from the sinus of Valsalva to the primary bifurcation was measured. All pulmonary arteries were void of any form of septation. The ligamentum arteriosum in each PA was not patent. The length of the PA from the sinus of Valsalva to the observed primary bifurcation was 5.0 cm and the diameter was 2.0 cm. (d = circumference / Pi). We conclude the PA is not a source of increased resistance and is a suitable conduit for AL implantation in the PA-PA or PA-LA configuration.