Article

Saphenous Vein Graft Aneurysm - An Unusual Cause of Mediastinal Mass

Register or Login to View PDF Permissions
Permissions× For commercial reprint enquiries please contact Springer Healthcare: ReprintsWarehouse@springernature.com.

For permissions and non-commercial reprint enquiries, please visit Copyright.com to start a request.

For author reprints, please email rob.barclay@radcliffe-group.com.

  • Views: 621

  • Likes: 0

  • Downloads: 1

  • Citations: 4

Average (ratings)
No ratings
Your rating

Abstract

We report the case of a 78-year-old man who was incidentally found to have a large, ovoid mass on a chest X-ray. Nineteen years before, he had undergone a coronary artery bypass graft (CABG). A chest computed tomography (CT) scan revealed a 6.8 x 6.7 cm aneurysm of the saphenous vein bypass graft anastomosed to the distal right coronary artery with contrast filling only the proximal end of the graft. The inferior wall of the left ventricle was akinetic on echocardiography, suggesting prior myocardial infarction of this vascular bed. Because of the patient’s comorbidities, occlusion of the graft, and prior inferior infarction, clinical observation was elected.

DOI:https://doi.org/10.15420/ahhj.2011.9.1.52

Copyright Statement:

The copyright in this work belongs to Radcliffe Medical Media. Only articles clearly marked with the CC BY-NC logo are published with the Creative Commons by Attribution Licence. The CC BY-NC option was not available for Radcliffe journals before 1 January 2019. Articles marked ‘Open Access’ but not marked ‘CC BY-NC’ are made freely accessible at the time of publication but are subject to standard copyright law regarding reproduction and distribution. Permission is required for reuse of this content.

Saphenous vein graft (SVG) aneurysms are a rare complication of coronary artery bypass grafting (CABG), typically occurring 10 to 20 years after surgery. In most cases, they present as an incidental finding on chest X-ray, and thus should be considered in the differential diagnosis of a chest mass in a patient with previous CABG. Although patients may be asymptomatic, these aneurysms can lead to myocardial ischemia or potentially rupture. Therefore, clinical recognition of this entity is an integral component of the management of CABG patients.

Case Presentation

A 78-year-old man presented with a large, asymptomatic ovoid mass on a posterior-anterior chest X-ray (see Figure 1). He had been admitted for management of a transient ischemic attack owing to carotid artery disease. Nineteen years before admission, the patient had undergone CABG with placement of a SVG to the distal right coronary artery. Past medical history also included ischemic cardiomyopathy (left ventricular ejection fraction, 25 %), hypertension, implantable cardiac defibrillator placement, and two transient ischemic attacks. The patient had stable New York Heart Association class II symptoms and no chest pain.

To evaluate the mass further, a CT chest with contrast was performed. This demonstrated a 6.8 x 6.7 cm occluded aneurysm within the body of the bypass graft to the right coronary artery (see Figure 2). Echocardiography demonstrated the inferior wall to be akinetic, consistent with a clinical history of prior inferior myocardial infarction (see Figure 3). Because resection of the aneurysm and revascularization of the inferior wall would be of minimal benefit, conservative management with clinical observation was elected.

Discussion

Saphenous vein graft aneurysms are defined as a permanent localized dilatation of >3 cm in diameter. Mild dilatation of saphenous grafts occur in up to 14 % of patients after CABG, but true aneurysms are believed to be rare.1 The lifetime incidence has been reported to be 0.07 %, but the true rate is unknown because patients are frequently asymptomatic.2 Among those who are found to have an SVG aneurysm, the average time from surgery is about 15 years.2

The pathophysiology of vein graft aneurysms is related to graft atherosclerosis, leading to structural weakness and subsequent dilation. Notably, pathologic studies have found that dilation begins near venous valves, where the muscle fibers of the vascular media have a longitudinal instead of circular orientation.3 In contrast, pseudoaneurysms more often occur near sites of surgical anastomosis. Surgical technical issues as well as infections are possibly involved in the formation of pseudoaneurysms.4,5

The most common presentation of SVG aneurysms is an incidental finding on chest X-ray, which occurs in about 50 % of these patients. Symptoms of myocardial ischemia are also common, occurring in about 40 %.1,6 Myocardial ischemia may occur, owing to distal embolization, thrombosis, fistula drainage with coronary steal, or mass effect on the native vessel.7 Approximately 5 % of patients present with heart failure. Other uncommon presentations include fistulas into the right atrium, right ventricle, pulmonary artery, or bronchi.8–12

Once the diagnosis is suspected, computer tomography with intravenous contrast is the test of choice. The goal of imaging is to determine the size of the aneurysm, its mass effects, and patency of the SVG. Two dimensional and Doppler echocardiography is helpful to determine cardiac function.13 Selective angiography of the vein graft frequently is required to examine through both the aneurysm and into the distal vascular bed.

Rupture of SVG aneurysms is the most feared complication, presenting as sudden death, hemothorax, hemopericardium, or massive hemoptysis. Because the natural history of SVG aneurysms is largely unknown, consensus on appropriate management is lacking. Large aneurysms with persistent flow are generally considered to have a higher risk of complications.

When considering surgical resection, other important factors are patient comorbidity and the need for revascularization of the distal arterial bed. In general, owing to potential life-threatening complications, surgery should be considered in all appropriate candidates. In selected patients, percutaneous therapy, consisting of vascular coils, occlusive devices (e.g. Amplater Septal Occluder), and covered stents have been used successfully.14–17

References

  1. Memon AQ, Huang RI, Marcus F, et al., Saphenous vein graft aneurysm: case report and review, Cardiol Rev, 2003,11:26–34.
  2. Dieter RS, Patel AK, Yandow D, et al., Conservative vs. invasive treatment of aortocoronary saphenous vein graft aneurysms: Treatment algorithm based upon a large series, Cardiovasc Surg, 2003;11:507–13.
  3. Vlodaver Z, Edwards JE, Pathologic changes in aortic-coronary arterial saphenous vein grafts, Circulation, 1971;44:719–28.
  4. de Haan HP, Huysmans HA, Weeda HW, et al., Anastomotic pseudoaneurysm after aorto-coronary bypass grafting, Thorac Cardiov Surg, 1985;33:55–6.
  5. Smith JA, Goldstein J, Saphenous vein graft pseudoaneurysm formation after postoperative mediastinitis, Ann Thorac Surg, 1992;54:766–8.
  6. Almanaseer Y, Rosman HS, Kazmouz G, et al., Severe dilatation of saphenous vein grafts: a late complication of coronary surgery in which the diagnosis is suggested by chest x-ray, Cardiology, 2005;104:150–5.
  7. Schamroth CL, Sacks AD, Aortocoronary saphenous vein bypass aneurysm—an unusual presentation, SAMJ S Afr Med J, 1998;88(Suppl 2):C91–3.
  8. Gruberg L, Satler LF, Pfister AJ, et al., A large coronary artery saphenous vein bypass graft aneurysm with a fistula: case report and review of the literature, Catheter Cardio Int, 1999;48:214–6.
  9. Riahi M, Stone KS, Hanni CL, et al., Right ventricular—saphenous vein graft fistula. Unusual complication of aorta-coronary bypass grafting, J Thorac Cardiov Surg, 1984;87:626–8.
  10. Dabboussi M, Saade YA, Poncet A, Baehrel B, Fistula between a saphenous vein graft aneurysm and the pulmonary artery trunk, Ann Thorac Surg, 2001;71:1356–8.
  11. Ivert T, Orre L, Right thoracotomy for saphenous vein graft aneurysm causing hemoptysis, Ann Thorac Surg, 2006;81:1885–7.
  12. Nishimura Y, Okamura Y, Hiramatsu T, et al., Hemoptysis caused by saphenous vein graft aneurysm late after coronary artery bypass grafting, J Thorac Cardiov Surg, 2005;129:1432–3.
  13. Dzavik V, Lemay M, Chan KL, Echocardiographic diagnosis of an aortocoronary venous bypass graft aneurysm, Am Heart J, 1989;118:619–21.
  14. Parry DJ, Winburn IC, Wilkins GT, Bunton RW, Expanding retrograde saphenous vein graft aneurysm treated with endovascular coiling, Ann Thorac Surg, 2005;80:2374–6.
  15. Kanani RS, Neilan TG, Palacios IF, Garasic JM, Novel use of the Amplatzer septal occluder device in the percutaneous closure of ascending aortic pseudoaneurysms: a case series, Catheter Cardior Int, 2007;69:146–53.
  16. Ho PC, Leung CY, Treatment of post-stenotic saphenous vein graft aneurysm: special considerations with the polytetrafluoroethylene-covered stent.[see comment], J Inv Cardio, 2004;16:604–5.
  17. Dixon SR, Skelding KA, Frumin HI, O’Neill WW, Occlusion of a saphenous vein graft aneurysm with a vein-covered stent, J Interv Cardio, 2002;15:201–4.
Previous Volume Article Next Volume Article