Pruned Tree and Leafless Tree Signs

In a 1951 review of the causes of pulmonary hypertension, William Evans ¹ described the pathologic and radiologic features of emphysema in a series of patients. Postmortem pulmonary arteriograms showed ‘pruning of the terminal branches of the pulmonary tree giving it an appearance of a denuded shrub in winter contrasting with the leafy bush in spring which typifies the healthy pulmonary circulation’ ¹ (Figure 1). Microscopically these abrupt pulmonary vascular terminations were said to be due to ‘endarteritis fibrosa.’ These findings in the living patient meant impending heart failure and an ‘unfavorable outlook.’ Evans used the word ‘pruning’ in the accompanying figure legend. The pruned tree terminology is more commonly used now than the phrase ‘denuded shrub.’ Figure 1 ‘Emphysema. Pulmonary arteriogram showing pruning effect of terminal branches in patient with pulmonary hypertension and heart failure [left], and compared with normal control [right].’ Reprinted from Evans’. Congenital pulmonary hypertension. Proc R. Soc <italic>Med.,</italic> 1951, 44, 600–8, with permission of the Royal Society of Medicine https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003076568/34c29fd5-5662-4e8f-b58c-badd7fa5d724/content/fig67_1_B.jpg"/>