Vasa vasorum of the pulmonary artery of the rabbit.

• During a study of the distensible behavior of the pulmonary artery in vivo, it was necessary to preserve its vasa vasorum to maintain the nutritional integrity of the vessel wall. In contrast to descriptions of the vasa vasorum of the normal aorta and other systemic arteries," the pulmonary artery vasa have received only passing comment." Winternitz, Thomas, and LeCompte noted that the degree of intramural vascularity of the pulmonary artery lies between the systemic veins and arteries; they did not further amplify or illustrate their observations. Both Miller and von Hayek, iu monographs on the lung, mentioned vasa vasorum of the pulmonary arteries and described them as originating from the bronchia] arteries; but they specifically referred to branches of the pulmonary artery and did not provide details of this vasal bed. In the absence of precise information about the pulmonary artery vasa, it was essential to determine the anatomical details of the arterial and venous vasa vasorum of the pulmonary artery from its origin to the entrance of the right and left pulmonary arteries into the lung. The variety of methods used to demonstrate vasa vasorum indicates the unsatisfactory result achieved with any one. While making silicone rubber injection casts of the circulation in this laboratory, consistent filling of some arterial vasa vasorum was noted. Subsequently, methods were developed to fill the vasa vasorum of the pulmonary artery in the living rabbit and to demonstrate their course and connections.