MYCOTIC PULMONARY ARTERY PSEUDOANEURYSM TREATED WITH ENDOVASCULAR COILING

Abstract

TOPIC: Procedures TYPE: Medical Student/Resident Case Reports INTRODUCTION: Mycotic pulmonary artery pseudoaneurysm (PAP) presents with a focal dilatation of the affected vessel as a result of infection that leads to significant wall weakening. PSA can be life-threatening if rupture occurs, thus aggressive intervention is usually thought to prevent catastrophic hemorrhage. Coil embolization or stent placement are the most frequently used treatments. We present a case of right middle lobe (RML) pulmonary artery segmental branch pseudoaneurysm successfully treated with endovascular coiling in a patient with history of tricuspid valve (TV) endocarditis, bacteremia, and septic pulmonary emboli. CASE PRESENTATION: Patient is a 27-year-old female with past medical history of IV drug use and Hepatitis C. She had recently been hospitalized for 45 days due to methicillin-susceptible S. aureus (MSSA) bacteremia and native TV endocarditis with septic emboli to the lungs. 5 days prior to discharge, CT pulmonary angiogram showed a 1.8 cm enhancing lesion concerning for a pseudoaneurysm within medial segment of the RML. Subsequent outpatient evaluation by interventional radiology two weeks later revealed normal hemodynamic parameters (HR 87 bpm, BP 143/88 mmHg, RR 20 breaths/min, O2 sat 97% on room air), and unremarkable coagulation profile (including Hb of 11.3 g/dL and Hct of 35%). Endovascular embolization of the PAP was planned. Briefly, pulmonary artery was accessed using a 0.035-inch guidewire & pigtail catheter. Initial non-selective pulmonary angiogram demonstrated faint visualization of the RML PAP. Subsequent selective right pulmonary artery medial branch angiogram confirmed the location of the PAP. The pigtail catheter was exchanged for a vertebral artery catheter through which a PROGREAT® microcatheter was advanced into the pseudoaneurysm sac. Position of the catheter within the sac was confirmed. Coil embolization was performed using Concerto™ coils. Post-coiling RML pulmonary artery angiogram showed obliteration of the aneurysmal sac with preservation of distal vessels. The patient tolerated the procedure well and was discharged the following day. DISCUSSION: The etiology of PAPs can be iatrogenic, infectious, traumatic, or related to malignancy. When linked to infection, PAPs most commonly occur in the settings of TV endocarditis and septic embolism, with Staphylococcus and Streptococcus as the usual culprits. In our patient, IV drug use led to the development of MSSA bacteremia and TV endocarditis. The subsequent hematogenous spread of septic emboli to the pulmonary artery resulted in pseudoaneurysm formation. CONCLUSIONS: Mycotic PAPs can occur in patients with S. aureus TV endocarditis and can be treated with endovascular coil embolization. REFERENCE #1: Chen, Y., Gilman, M. D., Humphrey, K. L., Salazar, G. M., Sharma, A., Muniappan, A., Shepard, J.-A. O., & Wu, C. C. (2017). Pulmonary Artery Pseudoaneurysms: Clinical Features and CT Findings. American Journal of Roentgenology, 208(1), 84–91. https://doi.org/10.2214/AJR.16.16312 REFERENCE #2: Guillaume, B., Vendrell, A., Stefanovic, X., Thony, F., & Ferretti, G. R. (2017). Acquired pulmonary artery pseudoaneurysms: A pictorial review. In British Journal of Radiology (Vol. 90, Issue 1074). British Institute of Radiology. https://doi.org/10.1259/bjr.20160783 DISCLOSURES: No relevant relationships by Emad Chishti, source=Web Response No relevant relationships by Gaby Gabriel, source=Web Response No relevant relationships by Marianna Zagurovskaya, source=Web Response