An unexpected cause of pulmonary hypertension.

A 56-year-old man was admitted for dyspnoea and haemoptysis. He was with no history of fever, tuberculosis, sarcoidosis, chronic obstructive pulmonary disease, asthma, and heart disease. He underwent oesophagogastrostomy for benign oesophageal mass 4 years ago. Physical examinations detected cardiac enlargement leftward and systolic murmur (grade 3/6) at tricuspid valve auscultatory area. Echocardiography revealed dilated right atrium and ventricle, compressed left atrium and ventricle, 141 mmHg of pulmonary artery systolic pressure, and 68% of left ventricular ejection fraction. Laboratory tests demonstrated normal serum IgG4 level, negative autoantibodies, 2.53 μg/mL of D-dimer, and 6478 pg/mol of N-terminal prohormone of brain natriuretic peptide. Right heart catheterization showed that mean pulmonary artery pressure was 84 mmHg, pulmonary artery wedge pressure 23 mmHg, cardiac index 2.15, and pulmonary vascular resistance 15.64 wood units, suggesting complex post-capillary pulmonary hypertension (Cpc-PH). Lung perfusion scan showed perfusion defects in inferior pulmonary lobes (Panel A). Computed tomography pulmonary angiography showed the enlarged right atrium and ventricle and revealed anatomic variations in left pulmonary vein (PV) and right PV, which coalesce and enter left atrium through one ostium. Moreover, the ostium was compressed by proliferative and fibrotic soft tissues in posterior mediastinum (Panels B–E), which suggests fibrosing mediastinitis (FM)-induced ostial stenosis. Barium meal examination indicated gastro-oesophageal anastomotic stenosis and fistula (Panel F). Together, we think that leakage from the fistula may induce proliferative fibrosis of mediastinal tissues, which compresses PV ostium and causes Cpc-PH. Notably, as for the FM caused by microbial infection, sarcoidosis, and autoimmune diseases, the stenosis is often located at draining branches of PVs and pulmonary lobe arteries, however, the stenosis in this case was observed only at the opening of the coalesced PVs. The pressure gradient across the lesion was 30 mmHg in the left PV and 27 mmHg in the right PV, as measured by a guiding catheter. Based on the opinions of thoracic surgeons, the anastomotic fistula had formed a blind end, and further leakage into the mediastinum had not been detected, hence reparative or interventional procedures from a surgical perspective were not necessary. Then, percutaneous transluminal PV stent implantation was performed to alleviate compression and ostial stenosis of PV, and the patient’s symptoms were significantly relieved. The long-term therapeutic efficacy of the stent implantation has been monitored by regular follow-ups.

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