Systemic-to-pulmonary shunts

A 28-year-old male was referred to the clinic due to recurrent hemoptysis over the preceding 7 years. The hemoptysis occurred every 2 to 3 months, mostly after physical exercise, with no accompanying dyspnea, chest pain, or fever. A decade earlier, he received bilateral thoracoscopic bullectomy with mechanical pleurodesis after 3 episodes of spontaneous pneumothorax. He smoked 1 cigarette per day for half a year before the pneumothorax first presented and quit smoking thereafter. Neither hemoptysis nor pneumothorax was noted among family members. His vital signs were stable. Pulse oximetry was 97% on room air. Physical examination of the skin, oral mucosa, chest and abdomen was unremarkable except for thoracoscopic surgery scars, and he has no peripheral edema. Contrast computed tomography revealed vascular malformations in the upper lobes (Figure 1A, B) without other abnormalities in the lung parenchyma. Aortic angiography confirmed the presence of systemic-to-pulmonary shunts. On the right side, connections were observed between the subclavian artery and pulmonary vein (Figure 1C). On the left side, a branch of the vertebral artery communicated directly with the pulmonary artery (Figure 1D). Echocardiogram did not reveal structural or functional alterations. The vascular malformations were suspected to represent complications of prior pleural fixation surgery, as the lesions were absent on preoperative imaging. Moreover, whole-exome sequencing conducted in the patient and his parents did not identify any pathogenic variations related to pulmonary bullae or vascular malformations.