Ann Thorac Surg 2005;80:2374-2376
© 2005 The Society of Thoracic Surgeons
Case report
Expanding Retrograde Saphenous Vein Graft Aneurysm Treated With Endovascular Coiling
Dominic J. Parry, MRCS (Ed)
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Ian C. Winburn, MRCS (Ed),
Gerald T. Wilkins, FRACP,
Richard W. Bunton, FRCAS
Dunedin Public Hospital, Dunedin, Otago, New Zealand
Accepted for publication July 14, 2004.
* Address correspondence to Dr Parry, Cardiothoracic Department, Dunedin Public Hospital, Great King St, Dunedin, Otago 9001, New Zealand (Email: donathanreeves{at}hotmail.com).
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Abstract
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Saphenous vein graft aneurysm is a potentially fatal complication of coronary artery bypass grafting and usually requires surgery. This report describes endovascular coiling of a saphenous vein graft aneurysm that developed after redo coronary artery bypass grafting. The aneurysm occurred in a proximally occluded saphenous vein graft after revascularization of the same target vessel. The procedure required a retrograde approach through a patent left internal mammary and left anterior descending artery to reach and successfully thrombose the aneurysm.
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Introduction
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Saphenous vein graft aneurysm is a rare but potentially dangerous complication of coronary artery bypass grafting. Historically, treatment has involved re-sternotomy, excision, and replacement of the affected graft. Aneurysmal dilatation of previously occluded aortocoronary vein grafts after redo coronary artery bypass grafting is even rarer. We describe such a case that was treated successfully by endovascular coiling.
A 57-year-old man was found to have a suspicious shadow arising from the left hilum on a routine chest roentgenogram (Fig 1). His past medical history included five aortocoronary saphenous vein bypass grafts in 1980 at age 35. He had redo coronary artery bypass grafting in 1999. Two skip grafts were fashioned; a pedicled left internal mammary artery graft was anastomosed end-to-side with the left anterior descending artery and side-to-side with the second diagonal. A saphenous vein graft was attached end-to-side with the posterior descending artery and side-to-side with an obtuse marginal branch of the circumflex artery. The original vein grafts were dilated, but occluded proximally and were left in situ. Postoperative recovery was uneventful.
Further investigation was required. Contrast enhanced computed tomography and magnetic resonance imaging demonstrated minor uptake in the lesion. Positron emission tomography showed absence of metabolic activity. Coronary angiography failed to identify flow into the mass. A diagnosis of a thrombosed aortocoronary aneurysm was made, and a conservative approach adopted.
Three months later the mass had enlarged on chest roentgenogram. Further coronary angiography identified an abnormal area of contrast enhancement arising from the left anterior descending artery, proximal to its anastomosis with the left internal mammary artery graft. This was suggestive of a saphenous vein graft aneurysm (SVGA) (Fig 2). Unusually the aneurysm filled retrogradely from the left internal mammary artery to the left anterior descending artery graft and had occurred in a venous conduit from the first operation. There was no inflow directly from the aorta. All redo coronary artery bypass grafts appeared disease free.
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Fig 2. Coronary angiogram of saphenous vein graft aneurysm (SVGA) showing its relationship to the left anterior descending artery (LAD), diagonal (DIAG) and left internal mammary (LIMA) arteries.
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Further revascularization was not required and percutaneous coil embolization was planned. After receiving 10,000 units of heparin, a guidewire was introduced into the SVGA in a retrograde fashion through the left internal mammary artery and the left anterior descending artery. Nine Hilal Embolization Microcoils were delivered into the aneurysm (six 50 x 1.5 mm, two 30 x 1 mm, and one 20 x 2 mm). Flow into the aneurysm slowed instantly, and 24 hours later the patient was discharged. A month later, angiography confirmed that the aneurysm had thrombosed (Fig 3). Six months later a computed tomographic scan demonstrated a decrease in its dimensions.
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Fig 3. Coronary angiogram of coiled saphenous vein graft aneurysm demonstrating absence of flow. (SVGA = saphenous vein graft aneurysm.)
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Comment
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There have been approximately 51 case reports of true SVGAs and 26 false SVGAs since 1975 [1]. True SVGAs form in atherosclerotic veins secondary to higher arterial pressures and sheer forces. Injuries incurred during vein harvesting and weaknesses in the vein walls at valve sites (where longitudinal smooth muscle in the media predominates over circular) may also be causative [2]. Hypertension and hyperlipidemia accelerate arteriosclerosis [3]. False aneurysms occur at leaking or infected anastomoses, usually in the early postoperative period.
Complications of SVGAs include distal embolization, myocardial infarction, and fistula formation [4]. Rupture causes cardiac tamponade or hemothorax, and it is rapidly fatal. Saphenous vein graft aneurysms typically present as incidental findings on chest roentgenogram, but patients may have angina, atypical chest pain, or a continuous murmur [4, 5]. Coronary angiography can appear relatively normal if the aneurysm sac contains a large amount of clot [6]. Computed tomography and magnetic resonance imaging are useful to exclude other pathologies and estimate the size of the aneurysm, and may show contrast enhancement.
This case is unique in that a blind ending aneurysmal sac had developed in a saphenous vein graft due to retrograde flow after a second revascularization of the same target vessel. This feature made diagnosis difficult, as there was no flow into the SVGA from the aorta, and the aneurysm did not enhance as brightly as a normal vascular structure on computed tomography or magnetic resonance imaging.
Treatment is aimed at preventing complications. Re-sternotomy and excision of the mass is usually required. If the affected graft does not require replacement, or if surgery is deemed high risk, we propose that endovascular coiling is an effective treatment. Coiling has also been used as an emergency intervention to treat ruptured aortocoronary aneurysms [5, 7].
Coiling SVGAs was first described in 1983 [5] and since then there have been five reported cases. However we believe this is the first time a retrograde approach has been performed successfully as described.
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References
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- Memon A, Huang RI, Marcus F, et al. Saphenous vein graft aneurysm Cardiol Rev 2003;11(1):26-34.[Medline]
- Schamroth CL, Sacks AD. Aortocoronary saphenous vein bypass aneurysm—an unusual presentation Cardiovasc Journ S Africa 1998(Suppl 2):C91-C93.
- Teja K, Dillingham R, Mentzer RM. Saphenous vein aneurysms after aortocoronary bypass graftingpostoperative interval and hyperlipidemia as determining factors. Am Heart J 1987;113:1527-1529.[Medline]
- Le Breton H, Pavin D, Langanay T, et al. Aneurysms and pseudoaneurysms of saphenous vein coronary artery bypass grafts Heart 1998;79:505-508.[Abstract/Free Full Text]
- Kim D, Guthaner DF, Wexler L. Transcatheter embolization of a leaking pseudoaneurysm of saphenous vein aortocoronary bypass graft Cathet Cardiovasc Diagn 1983;9:591-594.[Medline]
- Ferreira AC, de Marchena E, Awaad MI, et al. Saphenous vein graft aneurysm presenting as a large mediastinal mass compressing the right atrium Am J Cardiol 1997;79(5):706-707.[Medline]
- Dimitri WR, Reid AW, Dunn FG. Leaking false aneurysm of right coronary saphenous vein graftsuccessful treatment by percutaneous coil embolisation. Br Heart J 1992;68:619-620.[Abstract/Free Full Text]
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Abstract
Introduction
