Subpleural Lung Changes Adjacent to Enlarged Internal Mammary Artery in Patients with Coarctation of Aorta and Pulmonary Hypoplasia: Some Thoughts on an Interesting Observation.

Irregular pleural interface, minimally reduced lung density and/or focal subpleural cystic lung changes were noted in two patients with coarctation of aorta and in a patient with the right pulmonary hypoplasia. Lesions were distributed in the anterior segments of upper lobes, adjacent to internal mammary arteries (IMA). In view of unusual location of lung changes with unique distribution pattern prompted us to look for 'cause and effect' relation of events specific to long standing vascular pulsations, thus explaining the lung changes. While there are multiple factors for cystic lung disease, special distribution the lung changes seen in our patients leads us to explore mechanical process such as water hammer effect by dilated tortuous pulsatile IMA on the lungs as an additional etiology. A brief note on clinical and imaging appearance of our patients and discussion regarding water hammer theory are presented.