Aortocoronary Saphenous Vein Graft Aneurysm: Diagnosis Using Color Doppler and Contrast Transesophageal Echocardiography

Abstract

•SVG aneurysm may be diagnosed using TEE, color Doppler, and UEA.•An extracardiac mass after CABG raises suspicion of an SVG aneurysm.•Demonstration of flow by color Doppler or UEA aids in diagnosing SVG aneurysm.•SVG aneurysms are usually diagnosed ≥10 years after CABG (68%).•SVG aneurysms may cause extrinsic compression of adjacent structures (35%). Saphenous vein graft (SVG) aneurysms are rare and late complications of coronary artery bypass grafting (CABG).1Neitzel G.F. Barboriak J.J. Pintar K. Qureshi I. Atherosclerosis in aortocoronary bypass grafts: morphologic study and risk factor analysis 6 to 12 years after surgery.Arteriosclerosis. 1986; 6: 594-600Crossref PubMed Google Scholar, 2Riahi M. Vasu C.M. Tomatis L.A. Schlosser R.J. Zimmerman G. Aneurysm of saphenous vein graft to coronary artery.J Thorac Cardiovasc Surg. 1975; 70: 358-359Abstract Full Text PDF PubMed Google Scholar, 3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar, 4Steg P.G. Benacerraf M. Chatel D. Laissy J.P. False aortic aneurysm due to rupture of an aortocoronary saphenous vein bypass graft.Circulation. 1997; 96: 3778Crossref PubMed Scopus (10) Google Scholar, 5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar Aneurysms are frequently asymptomatic and diagnosed incidentally on chest computed tomographic angiography.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar, 4Steg P.G. Benacerraf M. Chatel D. Laissy J.P. False aortic aneurysm due to rupture of an aortocoronary saphenous vein bypass graft.Circulation. 1997; 96: 3778Crossref PubMed Scopus (10) Google Scholar, 5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar There are rare case reports in which they were diagnosed on transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE).3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar,5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar, 6Kobulnik J. Hutchison S.J. Leong-Poi H. Saphenous vein graft aneurysm masquerading as a left atrial mass: diagnosis by contrast transesophageal echocardiography.J Am Soc Echocardiogr. 2007; 20: 1414.e1-1414.e4Abstract Full Text Full Text PDF Scopus (8) Google Scholar, 7Omer M.A. Laster S.B. Amin A. Main M.L. Contrast-enhanced echocardiographic evaluation of a giant saphenous vein graft aneurysm.Echocardiography. 2016; 33: 1092-1094Crossref PubMed Scopus (0) Google Scholar Ultrasound enhancing agents (UEAs) were used in two previous reports.6Kobulnik J. Hutchison S.J. Leong-Poi H. Saphenous vein graft aneurysm masquerading as a left atrial mass: diagnosis by contrast transesophageal echocardiography.J Am Soc Echocardiogr. 2007; 20: 1414.e1-1414.e4Abstract Full Text Full Text PDF Scopus (8) Google Scholar,7Omer M.A. Laster S.B. Amin A. Main M.L. Contrast-enhanced echocardiographic evaluation of a giant saphenous vein graft aneurysm.Echocardiography. 2016; 33: 1092-1094Crossref PubMed Scopus (0) Google Scholar We present a case in which we used TEE with color Doppler and UEA for left heart opacification8Porter T.R. Mulvagh S.L. Abdelmoneim S.S. Becher H. Belcik J.T. Belick J.T. et al.Clinical applications of ultrasonic enhancing agents in echocardiography: 2018 American Society of Echocardiography guidelines update.J Am Soc Echocardiogr. 2018; 31: 241-274Abstract Full Text Full Text PDF PubMed Scopus (173) Google Scholar to visualize the flow in the lumen of the clot-filled SVG aneurysm to the right coronary artery (RCA). The diagnosis was confirmed on contrast enhanced cardiac computed tomography (CCT). A 74-year-old man with a history of hypertension, diabetes, dyslipidemia, and coronary artery disease presented with atypical chest pain and atrial fibrillation. He had undergone CABG and aortic valve replacement with a bileaflet St. Jude mechanical valve at 58 years of age. Chest computed tomography at an outside hospital revealed a right paracardiac mass suggestive of a “pericardial cyst” (Figure 1). He was taking carvedilol, losartan, furosemide, pravastatin, metformin, and warfarin daily. The physical examination demonstrated a healthy man in no apparent distress. His heart rate was 88 beats/min, and rhythm was irregular. His blood pressure was 128/67 mm Hg, with respiratory rate noted at 20 breaths/min. There was no evidence of jugular venous distention, with normal carotid upstroke. Cardiac examination demonstrated a normal apical impulse, normal opening and closing clicks of the aortic valve, and a grade 1 systolic ejection murmur at the base. Lung fields were clear to auscultation. There was no ankle edema, and peripheral pulses were equal and adequate. The laboratory data revealed normal complete blood count, normal electrolytes, and mildly elevated creatinine of 1.5 mg/dL. Electrocardiography demonstrated atrial fibrillation and nonspecific T-wave abnormalities. Chest radiography showed a prominent right heart border suspicious for a right paracardiac mass (Figure 2). TTE showed normal left ventricular wall motion, estimated ejection fraction of 65%, and normal function of the mechanical aortic valve prosthesis. TTE was technically difficult but suggestive of a 4.2-cm diameter round mass adjacent to the right atrium. The mass had a central small lumen, but no flow was noted on color flow imaging (Figure 3, Video 1). These abnormal findings on TTE were suspicious for SVG aneurysm and prompted us to perform TEE for clarification.Figure 3Two-dimensional TTE, modified right ventricular inflow view, shows a large circular mass (outlined by green arrows) just superior to the tricuspid valve (TV). There is a central echo-free space (yellow arrow). It appears to be inside the right atrium but actually is an extrinsic mass pushing the right atrial wall inward. This was later shown on TEE and CCT to be a clot-filled SVG aneurysm with a patent central lumen. LV, Left ventricle; RA, right atrium; RV, right ventricle.View Large Image Figure ViewerDownload Hi-res image Download (PPT) TEE using two-dimensional and three-dimensional imaging demonstrated a 4.2-cm-diameter extracardiac mass adjacent to the right atrium pushing the right atrial wall inward (Figure 4, Videos 2–4). The periphery of this structure showed clotlike echogenic material and flow in the central echo-free lumen with color flow imaging (Figure 4, Video 3). UEA was used for left heart opacification, and flow was noted in the central lumen (Figure 5, Videos 5 and 6). Findings on TEE, color Doppler, and flow imaging with UEA were consistent with the diagnosis of clot-filled SVG aneurysm to RCA with patent lumen.Figure 5Two-dimensional TEE midesophageal images 4-CV without (A) and with (B) UEA. UEA (0.5 mL perflutren protein type A microspheres) was injected intravenously, followed by 3-mL flush with normal saline for left heart opacification. The mechanical index was lowered to 0.5, and gain was increased. (Panel A) Appearance of UEA in the left atrium (LA) but an echo-free graft lumen early after UEA injection (yellow arrow). (B) UEA within the lumen 1 min later (yellow arrow). These echocardiographic features are consistent with the subsequently proven clotted SVG aneurysm with a patent lumen. LV, left ventricle; RA, right atrium; RV, right ventricle.View Large Image Figure ViewerDownload Hi-res image Download (PPT) The patient was referred for coronary and graft angiography, but the SVG was not successfully engaged. CCT showed a patent left internal mammary artery graft to the left anterior descending coronary artery, a patent SVG to the diagonal branch, and an aneurysm of the SVG to the RCA (Figure 6). Because of the lack of significant ischemia, medical management was recommended. He underwent ablation for atrial fibrillation, but because of recurrence of arrhythmia he was started on amiodarone with maintenance of sinus rhythm. A minor degree of aneurysmal dilation of the SVG is not uncommon and has been reported to be as high as 14% at 6 to 12 years after CABG.1Neitzel G.F. Barboriak J.J. Pintar K. Qureshi I. Atherosclerosis in aortocoronary bypass grafts: morphologic study and risk factor analysis 6 to 12 years after surgery.Arteriosclerosis. 1986; 6: 594-600Crossref PubMed Google Scholar Large aneurysms of the SVG graft are rare and reported mostly as single case reports or small case series. It was first reported by Riahi et al2Riahi M. Vasu C.M. Tomatis L.A. Schlosser R.J. Zimmerman G. Aneurysm of saphenous vein graft to coronary artery.J Thorac Cardiovasc Surg. 1975; 70: 358-359Abstract Full Text PDF PubMed Google Scholar in 1975, and since then several other case reports and reviews have been published.2Riahi M. Vasu C.M. Tomatis L.A. Schlosser R.J. Zimmerman G. Aneurysm of saphenous vein graft to coronary artery.J Thorac Cardiovasc Surg. 1975; 70: 358-359Abstract Full Text PDF PubMed Google Scholar,7Omer M.A. Laster S.B. Amin A. Main M.L. Contrast-enhanced echocardiographic evaluation of a giant saphenous vein graft aneurysm.Echocardiography. 2016; 33: 1092-1094Crossref PubMed Scopus (0) Google Scholar,9Ramirez F.D. Hibbert B. Simard T. Ali P. Wilson K.R. Hibbert R. et al.Natural history and management of aortocoronary saphenous vein graft aneurysms: a systematic review of published cases.Circulation. 2012; 126: 2248-2256Crossref PubMed Scopus (77) Google Scholar SVG aneurysms can be true aneurysms or pseudoaneurysms.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar,4Steg P.G. Benacerraf M. Chatel D. Laissy J.P. False aortic aneurysm due to rupture of an aortocoronary saphenous vein bypass graft.Circulation. 1997; 96: 3778Crossref PubMed Scopus (10) Google Scholar Pseudoaneurysms of the SVG are rare, involve the proximal or distal anastomotic site, and are thought to be related to infection or surgical technique. They usually occur early within the first few months after operation,3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar and rare late occurrence has been reported several years later.4Steg P.G. Benacerraf M. Chatel D. Laissy J.P. False aortic aneurysm due to rupture of an aortocoronary saphenous vein bypass graft.Circulation. 1997; 96: 3778Crossref PubMed Scopus (10) Google Scholar True SVG aneurysms account for the majority of cases and are generally reported years after CABG.2Riahi M. Vasu C.M. Tomatis L.A. Schlosser R.J. Zimmerman G. Aneurysm of saphenous vein graft to coronary artery.J Thorac Cardiovasc Surg. 1975; 70: 358-359Abstract Full Text PDF PubMed Google Scholar,7Omer M.A. Laster S.B. Amin A. Main M.L. Contrast-enhanced echocardiographic evaluation of a giant saphenous vein graft aneurysm.Echocardiography. 2016; 33: 1092-1094Crossref PubMed Scopus (0) Google Scholar,9Ramirez F.D. Hibbert B. Simard T. Ali P. Wilson K.R. Hibbert R. et al.Natural history and management of aortocoronary saphenous vein graft aneurysms: a systematic review of published cases.Circulation. 2012; 126: 2248-2256Crossref PubMed Scopus (77) Google Scholar Occasionally true aneurysm has been reported early, within a few months after CABG. This is probably related to preexisting weakness of venous wall or injury at the time of harvesting.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar Ramirez et al9Ramirez F.D. Hibbert B. Simard T. Ali P. Wilson K.R. Hibbert R. et al.Natural history and management of aortocoronary saphenous vein graft aneurysms: a systematic review of published cases.Circulation. 2012; 126: 2248-2256Crossref PubMed Scopus (77) Google Scholar performed a systematic review of cases between 1975 and 2010 and reported data on 209 cases of SVG aneurysms. They were diagnosed late, >10 years after CABG, in 68%, most frequently involved SVG to the RCA (in 38%), caused mechanical complications and extrinsic compression of adjacent structures in 35%, and ruptured into a cardiac chamber with fistula in 7.7%. The clinical presentations of SVG aneurysm include incidental finding on imaging (chest radiography, echocardiography, CCT),3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar,7Omer M.A. Laster S.B. Amin A. Main M.L. Contrast-enhanced echocardiographic evaluation of a giant saphenous vein graft aneurysm.Echocardiography. 2016; 33: 1092-1094Crossref PubMed Scopus (0) Google Scholar,9Ramirez F.D. Hibbert B. Simard T. Ali P. Wilson K.R. Hibbert R. et al.Natural history and management of aortocoronary saphenous vein graft aneurysms: a systematic review of published cases.Circulation. 2012; 126: 2248-2256Crossref PubMed Scopus (77) Google Scholar right extracardiac mass,5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar left extracardiac mass6Kobulnik J. Hutchison S.J. Leong-Poi H. Saphenous vein graft aneurysm masquerading as a left atrial mass: diagnosis by contrast transesophageal echocardiography.J Am Soc Echocardiogr. 2007; 20: 1414.e1-1414.e4Abstract Full Text Full Text PDF Scopus (8) Google Scholar causing compression of adjacent structures,9Ramirez F.D. Hibbert B. Simard T. Ali P. Wilson K.R. Hibbert R. et al.Natural history and management of aortocoronary saphenous vein graft aneurysms: a systematic review of published cases.Circulation. 2012; 126: 2248-2256Crossref PubMed Scopus (77) Google Scholar ischemia,10Sahouri S.J. Steele R.L. Aneurysm of saphenous vein graft to coronary artery presenting as non-Q-wave myocardial infarction secondary to mass effect.Cathet Cardiovasc Diagn. 1995; 34: 325-328Crossref PubMed Scopus (23) Google Scholar rupture,11Murphy Jr., J.P. Sharbb B. Nishikawa A. Adams P.R. Walker W.E. Rupture of an aortocoronary saphenous vein graft aneurysm.Am J Cardiol. 1986; 58: 555-557Abstract Full Text PDF PubMed Scopus (62) Google Scholar and fistula to the right atrium12Richardson M.P. Thuraisingham S.I. Dunning J. Apparent obstruction of the superior vena cava and continuous murmur: signs of a fistula between a vein graft aneurysm and the right atrium.Br Heart J. 1992; 68: 412-413Crossref PubMed Scopus (14) Google Scholar or to the right ventricle.13Riahi M. Stone K.S. Hanni C.L. Fierens E. Dean R.E. Right ventricular—saphenous vein graft fistula: unusual complication of aortocoronary bypass grafting.J Thorac Cardiovasc Surg. 1984; 87: 626-628Abstract Full Text PDF PubMed Google Scholar TTE and chest radiography are usually the first diagnostic studies performed in cardiac patients. Transthoracic echocardiographic images were poor in our case but suggestive of a mass adjacent to the right atrium, prompting us to perform TEE for clarification. TEE with color Doppler and contrast-enhanced imaging provided details of graft flow and aided in the diagnosis. Coronary angiography is useful to rule out obstructive disease and evaluate grafts. At times, it is challenging to fill the large aneurysmal graft, as in this case. CCT is the diagnostic imaging modality of choice.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar Cardiac magnetic resonance imaging has also been used.4Steg P.G. Benacerraf M. Chatel D. Laissy J.P. False aortic aneurysm due to rupture of an aortocoronary saphenous vein bypass graft.Circulation. 1997; 96: 3778Crossref PubMed Scopus (10) Google Scholar The presence of a paracardiac mass on imaging studies in a patient after cardiac surgery (CABG or aortic surgery) should alert the clinician to the possibility of SVG aneurysm, pericardial hematoma, or pseudoaneurysm of the aorta.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar,5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar,14Razzouk A. Gundry S. Wang N. Heyner R. Sciolaro C. Arsdell G.V. et al.Pseudoaneurysms of the aorta after cardiac surgery or chest trauma.Am Surg. 1993; 59: 818-823PubMed Google Scholar Pericardial cyst is a rare cardiac lesion that should be in the differential diagnosis.15Alqassieh R. Al-Balas M. Al-Balas H. Anesthetic and surgical considerations of giant pericardial cyst: case report and literature review.Ann Med Surg. 2020; 55: 275-279Crossref PubMed Scopus (1) Google Scholar Experienced echocardiographers are often able to use all available echocardiographic imaging parameters to best differentiate SVG aneurysm from pericardial cyst, pericardial hematoma, or pseudoaneurysm of the aorta. However, when appropriate, additional tomographic imaging modalities such as cardiac magnetic resonance and CCT remain valuable for greater clarification and comprehensive evaluation (see Supplemental Figures 1–4). In a patient with a history of CABG, a mass adjacent to the heart on chest radiography or TTE should alert the clinician to the possibility of SVG aneurysm, pseudoaneurysm of the aorta, or pericardial hematoma.3Wight Jr., J.N. Salem D. Vannan M.A. Pandian N.G. Bankoff M. Rozansky M.I. et al.Asymptomatic large coronary artery saphenous vein bypass graft aneurysm: a case report and review of the literature.Am Heart J. 1997; 133: 454-460Crossref PubMed Google Scholar,5Bansal R.C. Echocardiographic diagnosis of an asymptomatic aneurysm of a saphenous vein graft.J Am Soc Echocardiogr. 2002; 15: 661-664Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar,14Razzouk A. Gundry S. Wang N. Heyner R. Sciolaro C. Arsdell G.V. et al.Pseudoaneurysms of the aorta after cardiac surgery or chest trauma.Am Surg. 1993; 59: 818-823PubMed Google Scholar A high index of suspicion is required, and imaging specialists should be aware of this complication of CABG. Systematic TTE and TEE with color Doppler and flow imaging with UEA offer the opportunity to confirm the diagnosis of SVG aneurysm. Complete coronary and SVG evaluation require multimodality imaging, including CCT and selective coronary angiography.