An Unusual Echodensity in the Ascending Aorta: Transesophageal Echocardiographic Visualization of a Protruding Coronary Stent

Abstract

A 73-yr-old woman with a history of single-vessel coronary artery disease presented for off-pump coronary artery bypass grafting (CABG). Almost 2 yr before her presentation, she underwent placement of a paclitaxel drug-eluting stent (Taxus, Boston Scientific, Natick, MA) in an ostial right coronary artery (RCA) stenosis. She required two further interventions to this stent 1 and 12 mo after the initial stent placement. In both instances, the patient developed anginal symptoms and cardiac catheterization revealed occlusion of the intracoronary stent. In both cases, a new coronary artery stent was placed within the lumen of the previous stent after successful balloon dilation. Two days before surgery, she presented with unstable angina and coronary angiography revealed re-occlusion of the RCA stent(s). A wire could not be placed into the lumen of the stent(s) during the catheterization, and the patient was referred for surgery. Transesophageal echocardiography (TEE) performed after anesthesia induction demonstrated moderate to severe mitral regurgitation, mild aortic regurgitation, and an almost 1-cm long, lasso-shaped echodensity in the proximal ascending aorta just distal to the aortic valve leaflets (Fig. 1). Further examination revealed the mass to emanate from the RCA ostium and to limit systolic motion of the right coronary cusp of the aortic valve. On the basis of these findings, the surgical procedure was changed to a CABG, mitral valve repair, and exploration of the ascending aorta.Figure 1.: Intraoperative transesophageal echocardiographic image showing an echodense “loop”(red arrow) in the ascending aorta just distal to the right coronary cusp of the aortic valve in this midesophageal aortic valve long-axis view. LVOT = left ventricular outflow tract.Exploration of the ascending aorta revealed the echodense mass to be a coronary stent protruding approximately 7 mm into the aorta from the RCA ostium. The right coronary cusp displayed fibrotic changes at the point of contact with the stent. The stent was cut at the point of emanation and removed (Fig. 2). The patient then underwent successful CABG of the RCA and mitral valve annuloplasty.Figure 2.: 0.7 × 0.4 cm section of coronary artery stent removed from the aorta. The video loop (available at www.anesthesia-analgesia.org) shows a midesophageal aortic valve long-axis view of the mass in the ascending aorta. The clip is shown in slow motion.This report describes an unusual echodensity in the ascending aorta found during intraoperative TEE. This finding had direct impact on the surgical plan and procedure. The differential diagnoses considered included imaging artifact, aortic dissection, intramural hematoma, aortic fibroelastoma, aortic atheromatous disease with associated calcification, and foreign body. TEE imaging from multiple planes suggested that the finding was not an imaging artifact. Possible algorithms considered for treatment included postponement of surgery with evaluation by other imaging techniques, including computed tomography and/or magnetic resonance imaging. Ultimately, in this case, it was decided that surgical exploration of the ascending aorta was most practical. TEE visualization of intracoronary stents has been reported (1,2) as has visualization of pathology affecting the coronary ostia (3,4). In contrast, these previous case reports relate to patients in nonoperative settings.