Images of septic thromboembolism from superior vena cava to lung.

Abstract

A 68-year-old woman with end-stage renal disease was started on regular hemodialysis with a tunneled cuffed catheter through the right internal jugular vein for 2 months. She entered our emergency department with complaints of fever, shortness of breath, and chest pain of 2 days duration. On arrival, she was febrile, tachycardic, tachypneic, and had a normal blood pressure. No erythema, swelling, heat, or tenderness was observed at the insertion site of the dialysis catheter. No abnormal breath sounds or audible heart murmurs were detected. Oxygen saturation was 88 % while breathing room air. The electrocardiogram revealed sinus tachycardia. Laboratory examination revealed leukocytosis, thrombocytopenia, and elevated C-reactive protein. An initial chest radiograph (Fig. 1) showed multiple ill-defined opacities in the right lung and the tip of the dialysis catheter was placed in the right atrium (RA). Based on the clinical manifestations and chest radiographic findings, a dialysis catheter-related infection with septic pulmonary embolism (SPE) was suspected. The patient was treated with empirical vancomycin. Contrastenhanced computed tomography (CT) (Fig. 2a–c) performed after dialysis catheter removal revealed that the thrombi were in the superior vena cava (SVC), RA, right ventricle (RV), and right interlobar pulmonary artery branch. CT findings on lung window setting (Fig. 3a–d) showed different types of SPE. A transthoracic echocardiography revealed a 45 9 26 mm thrombus within the RA, which was attached to the wall of the atrium, and protruded into the RV (Fig. 2d). The RA and RV were of normal size. Mild tricuspid regurgitation and mild pulmonary hypertension (estimated pulmonary artery systolic pressure 32 mmHg) were detected. Anticoagulation therapy was initiated. The catheter tip culture and three pairs of blood cultures were positive for oxacillin-sensitive Staphylococcus aureus. Based on radiographic evidence of thrombi and positive blood culture results, the diagnoses of septic thrombophlebitis of the SVC, septic thrombosis of the RA with pulmonary embolism (PE), and SPE were confirmed. In a previous study, approximately 12.5 % of patients exhibit thrombus at the tip of catheter within 6–8 weeks of catheter insertion, and all thrombi are found in those patients with the catheter tip position in the RA, in contrast to none in those with the catheter tip position in the SVC [1]. The likely mechanism of thrombus formation at this location is related to friction of the catheter on the atrial endocardium [2, 3]. The endothelial damage induced by trauma results in platelet aggregation and thrombus formation [4]. An adherent infected thrombus in the RA may become dislodged, and lead to PE and SPE. Great diversity of SPE can be found in CT findings, including a feeding vessel sign, nodules with or without cavities, pleural effusions, peripheral wedge-shaped opacities, patchy ground-glass opacities, lung abscesses, and focal consolidations [5]. A chest radiograph can assist in diagnosis of this disease, as seen in the present case. A possible diagnosis of dialysis catheter-related SPE from a chest radiograph may & Deng-Wei Chou choudw@gmail.com