This article will detail late results following ligation of the left pulmonary artery in dogs, without and with simultaneous section of the phrenic nerve.
In a previous report1 it was shown that the operative procedure is unassociated with any definite shock, that the animals regain normal activity within twenty-four hours and remain so until the experiment is terminated, as much as four months later.
In the interval included in the reported experiments, the lung with intact pulmonary artery expands and herniations in the thinnest areas of the mediastinum occur, but this process becomes stabilized after a month. On the other hand, the lung with ligated pulmonary artery gradually decreases in size, and this process progresses more rapidly when the phrenic nerve has been sectioned. Collateral circulation is established by increase in the caliber of the bronchial artery which doubles its size in three months but somewhat less rapidly when