Ascending Aortic Pseudoaneurysm : A Late Complication of Coronary Artery Bypass

An 83-yr-old man, with a history of myocardial infarction and coronary artery bypass grafting surgery performed 21 yr ago, presented with increasing midsternal chest pain radiating to his back and shortness of breath. He was diagnosed with a non-ST-elevation myocardial infarction. Cardiac catheterization showed an occluded saphenous vein graft to the first diagonal branch and a mass attached to the ascending aorta with uncertain involvement of the saphenous vein graft. Magnetic resonance imaging (MRI) showed a pseudoaneurysm, measuring 4.6 12.5 cm, which appeared to originate from the saphenous vein graft to the diagonal branch. The pseudoaneurysm had bloodflow into an approximately 5 2.4 cm oblong space that was surrounded by a spherical, heterogeneous, formed hematoma. The pseudoaneurysm extended superiorly to the level of the aortic arch and inferiorly to the level of the diaphragm. It significantly compressed the superior vena cava, right atrium (RA), and right ventricle (RV). Surgery to excise the pseudoaneurysm was planned with right subclavian artery/femoral vein cardiopulmonary bypass and deep hypothermic circulatory arrest. Radial and pulmonary arterial catheters were placed for hemodynamic monitoring; no significant RV pressure increase was noticed (34/4 mm Hg). A thorough intraoperative transesophageal echocardiography (TEE) was performed to look for the characteristics of a pseudoaneurysm that include a thin-walled cavity and expansion during systole and collapse during diastole. The TEE showed a thin-walled cavity that was filled with a nonhomogeneous material and did not expand or collapse with systole and diastole. Color Doppler examination showed what appeared to be bloodflow in the cavity (Video clips 1 and 2; please see video clips available at www.anesthesia-analgesia. org), but this finding did not correlate with the location of bloodflow demonstrated previously by MRI and angiography. The TEE confirmed RA and RV compression with mild tricuspid regurgitation (Figs. 1, 2, and Video clip 1). The aortic valve (AV) appeared normal in both the mid-esophageal (ME) AV short and long axis views. The ascending aorta was also normal from the upper esophageal aortic arch long axis view, ME AV long axis view, ME ascending aortic long axis view, and the ME left ventricular (LV) long axis view. A right anterior thoracotomy approach was used and, after cardiopulmonary bypass was established, the patient’s temperature was decreased to 20°C. The pseudoaneurysm was excised and brown-colored fluid with necrotic material was evacuated. During careful inspection, two small holes were identified in the lateral wall of the ascending aorta located 1.5 cm above the aortic valve. The bleeding pressure from the two holes was very low and no communication with the saphenous vein graft was noted. Suture repair of the ascending aorta was made easier by a transient 2-min circulatory arrest. After resection of the pseudoaneurysm, the compression of the RA and RV were significantly relieved (Video clip 2). The descending aorta was then carefully examined by TEE and no additional pathology was found. The patient recovered uneventfully. A pseudoaneurysm, also known as a false aneurysm, is an outpouching of a blood vessel caused by a defect in the two innermost layers (tunica intima and media) with continuity of the outermost layer (tunica adventitia). Alternatively, all three layers are damaged and the bleeding is contained by a blood clot or This article has supplementary material on the Web site: www.anesthesia-analgesia.org.