Imaging of acquired transdiaphragmatic fistulae and communications

Acquired diaphragmatic defects occur secondary to trauma, infection, surgery or neoplasm. These defects can lead to abnormal thoraco-abdominal fistulous communications also. Examples of surgically created diaphragmatic defects are omental, colonic interposition and vascular grafts. Regardless of etiology, these transdiaphragmatic communications provide a direct path for spread of pathology between the abdomen and thorax. If left untreated and unrecognized, these fistulae portend a high morbidity and mortality. Subtle but important diagnostic clues can be present on imaging. This pictorial essay describes commonly encountered imaging findings seen with acquired transdiaphragmatic communications. This knowledge will improve diagnostic confidence of the interpreting radiologist in acute situations and confounding clinical scenarios.