C18 role of Three Dimensional Echocardiography in Imaging and Surgical Decision Making of Aorto–left Atrial Fistula

Abstract

A 63–year–old female known case of diabetes, hypertension, dyslipidemia and chronic kidney disease underwent mitral valve (MV) replacement because of severe regurgitation (RGT). Few weeks after, she was admitted due to decreased level of consciousness, drowsiness, abdominal distension and fever. Laboratory investigations showed positive blood cultures for Staphylococcus aureus and elevated inflammatory markers. Brain computed tomography (CT) revealed multiple infarcts due to systemic embolization. Transthoracic echocardiography (TTE) showed bioprosthesis (BP) leaflets coated by a mass causing significant obstruction (peak/mean=17/8 mmHg) with mild intravalvular RGT. Mild thickening of aortic valve (AV) cusps with mild RGT and moderate tricuspid RGT were also noted. Left and right ventricles were normal in size and function. A transesophageal echocardiography (TEE) (Figure 1) showed BP leaflets coated by a mass with a mobile vegetation attached on the atrial surface (10x9mm) causing severe obstruction and mild intravalvular RGT. A periaortic abscess, surrounding the left and the non–coronary cusps and involving the mitro–aortic fibrosa was also found. A fistula between the aortic root and the left atrium was detected by color Doppler and CW Doppler (systodiastolic high velocity shunt) (Figure 1). Further three dimensional (3D) analysis allowed to anatomically locate the position of the fistula which started close to the ostium the left coronary (LC) artery, passing through the mitroaortic fibrosa and opening anteriorly next to the strut of the BP (Figure 2). Contrast cardiac CT was advised but it was not performed to avoid further kidney impairment. The consensus was to perform redo–surgery. Therefore, the patient underwent MV cleaning of abscessual area, reconstruction of the aortic annulus with AV replacement. A coronary artery bypass surgery on LC artery was also necessary as the ostium was narrowed during the reconstruction of the area. Echocardiographic findings were confirmed at surgery. In our case 3DTEE accurately delineated cardiac anatomy and provided crucial anatomic details useful in the surgical planning. It is also important to highlight that the diagnosis may be challenging as the jet may be misinterpreted as mitral RGT. In this context, 3D imaging offers incremental value, as it is able to offer a clear view of the mitral valve.3DTEE was particularly helpful in our setting because the patient was at high risk to perform contrast study.