Severe Pulmonary Artery Stenosis Caused by Extrinsic Compression of a Calcified Circular Ring
A 35-year-old man visited our hospital with dyspnea on exertion and edema on his face and both legs that had grown worse over several months. He had a 15-year-long history of treatment for pulmonary tuberculosis. On physical examination, a grade 4/6 pansystolic murmur was heard at the 4th intercostal space along the left sternal border. Chest radiography revealed enlargement of the right ventricle and the left pulmonary trunk. Interestingly, a calcified circular ring was noted around the great vessels (Figure 1). Echocardiography showed severe pulmonary hypertension (98.1 mm Hg) caused by severe stenosis of the main pulmonary artery at the supravalvular level, which resulted in enlarged right artery and right ventricle chamber dimensions (Figure 2A and 2B). Right heart catheterization demonstrated elevated right ventricle pressure (71 mm Hg), even though we used the full dose of medication to reduce preload and afterload (Figure 2C). On chest CT angiogram, there was a calcified ring encircling the ascending aorta and the main pulmonary artery, and the main pulmonary artery was compressed by that ring with poststenotic dilatation (Figure 3A and 3B). Pulmonary artery angiogram also showed similar findings (Figure 3C). Surgery was performed, and the calcified ring was removed entirely except for the posterior portion, which had adhered tightly to the aorta (Figure 4). Biopsy specimens showed an extensive dystrophic calcification and dense fibrosis. After removing the calcified ring, graft repair was performed at the stenotic area of the main pulmonary artery to remove pulmonary artery pressure gradient. After surgery, follow-up echocardiography revealed normalized pulmonary artery pressure and the patient was discharged with relief of exertional dyspnea and edema on his face and both legs.