REPERFUSION PULMONARY EDEMA AFTER RESECTION OF A MALIGNANT SOLITARY FIBROUS TUMOR OF THE PLEURA MANAGED WITH VENOVENOUS EXTRACORPOREAL MEMBRANE OXYGENATION

Abstract

TOPIC: Disorders of the Pleura TYPE: Medical Student/Resident Case Reports INTRODUCTION: Solitary fibrous tumors of the pleura (SFTP) are rare tumors that account for 5% of all primary pleural tumors. SFTP originate from the submesothelial mesenchymal layer of the pleura from primitive fibroblast or mesenchymal cells. Although most are benign and can be cured by complete resection, malignant forms of SFTP are known to recur more frequently. CASE PRESENTATION: A 66-year-old female with history of hypertension and prior resection of an SFTP via median sternotomy in 2004 (pathology unknown) presented with increasing dyspnea on exertion over the previous four weeks, greatly decreasing her functional status. Imaging revealed a large soft tissue mass occupying most of the right hemithorax and displacing the mediastinum to the left (Figure 1). Patient underwent resection of the large right SFTP via a right thoracotomy with lung isolation via a double lumen ET tube. Upon re-expansion of the right lung at the end of the case, patient became acutely hypoxic and hypotensive, with massive bilateral pulmonary edema on bronchoscopy. Condition persisted despite aggressive suctioning and increased ventilatory and vasopressor support, and patient was emergently placed on venovenous (VV) ECMO in the OR via a 21F right femoral vein cannula and a 17F right internal jugular vein cannula. The patient's hypoxia resolved and blood pressure stabilized on vasoactive drips, while massive pulmonary edema resolved gradually through discharge on POD15. Post-op course complicated by tamponade physiology that required emergent pericardiocentesis, AKI requiring hemodialysis (with full recovery), and atrial fibrillation requiring cardioversion, with resultant stabilization in hemodynamics. ECMO support was discontinued on POD3. Final pathology revealed a 22 x 18 x 10.5cm malignant SFTP with 5 mitotic figures per 10 high power fields. DISCUSSION: RPE is characterized by pulmonary edema plus or minus clinical symptoms, sometimes including hemodynamic instability, after rapid re-inflation of a previously collapsed lung. Although almost exclusively described after drainage of pneumo- or hemothorax in the literature [1], this rare phenomenon is the most likely cause of the massive pulmonary edema seen in our patient with long-term lung compression by SFTP. The pathophysiology of RPE likely includes tissue reperfusion, hypoxia, and free radial damage, among other processes, as the mechanism for lung damage and pulmonary edema. Treatment is generally supportive based on the clinical manifestations of RPE, including ECMO in our case and only two other cases reported in the literature [2, 3]. CONCLUSIONS: VV ECMO allows for complete lung rest while providing adequate oxygenation for end organ perfusion, although not without possible complications, most concerning of which are hemorrhagic. This case is the first to demonstrate the successful use of VV ECMO in a very rare case of RPE after resection of a malignant SFTP. REFERENCE #1: Meeker JW, Jaeger AL, Tillis WP. An uncommon complication of a common clinical scenario: exploring reexpansion pulmonary edema with a case report and literature review. J Community Hosp Intern Med Perspect. 2016; 6:32257. REFERENCE #2: Tung YW, Lin F, Yang MS et al. Bilateral developing reexpansion pulmonary edema treated with extracorporeal membrane oxygenation. Ann Thorac Surg 2010; 89:1268-1271. REFERENCE #3: Shires AL, Green TM, Owen HL et al. Case 4--2009. Severe reexpansion pulmonary edema after minimally invasive aortic valve replacement: management using extracorporeal membrane oxygenation. J Cardiothorac Vasc Anesth 2009; 23:549-554. DISCLOSURES: No relevant relationships by Ann Defnet, source=Web Response No relevant relationships by Harvey Pass, source=Web Response No relevant relationships by Deane Smith, source=Web Response No relevant relationships by Gerardo Velez, source=Web Response