Operative Strategies for Pulmonary Artery Occlusion Secondary to Mediastinal Fibrosis

Abstract

Fibrosing mediastinitis is a rare disease characterized by an excessive fibrotic reaction in the mediastinum, which may entrap mediastinal structures including the pulmonary arteries. Our objectives were to assess the surgical strategies and outcomes of repair of pulmonary artery occlusion attributable to mediastinal fibrosis. With approval from the Mayo Clinic Institutional Review Board, we identified all patients with fibrosing mediastinitis who underwent an operation for relief of pulmonary artery obstruction between 1980 and 2008. Perioperative data were collected using medical records and late follow-up surveys. Operative procedures to bypass or reconstruct an obstructed pulmonary artery were performed in 5 patients. Patients' median age was 40 years (range, 27 to 51 years), and all patients were symptomatic and had right ventricular hypertension. In 3 patients, a double-outlet right ventricle was constructed using a valved conduit (porcine valved conduit, n = 1; aortic homograft, n = 2) from the right ventricle to the right pulmonary artery. Two patients required complete reconstruction of the pulmonary artery confluence using a pulmonary homograft in 1 patient and a hybrid technique of autologous pericardial reconstruction and intraoperative stenting in another patient. All patients had a reduction in right ventricular pressures after operation. One patient died perioperatively owing to respiratory failure; the remaining 4 patients were alive at a median follow-up of 7.4 years (range, 0.5 to 14.7 years). One patient required late balloon dilatation of the conduit and distal pulmonary arteries 10 years after initial operation, but the remaining conduits were widely patent at late follow-up. Late functional improvement was limited owing to other complications from mediastinal fibrosis or other comorbidities. Treatment of pulmonary artery occlusion attributable to mediastinal fibrosis can be challenging. Successful operative strategies include both creation of a double-outlet right ventricle and complete reconstruction of the pulmonary artery confluence. Hybrid techniques of both conduit placement and stenting should also be considered for patients with occluded pulmonary arteries.