Ann Thorac Surg 2000;69:271-273
© 2000 The Society of Thoracic Surgeons
Case Reports
Aortic pseudoaneurysm after ligation of aneurysmal saphenous vein graft
Brent A. Grishkin, MDa,
Robert A. Helsel, MDa
a Fort Sanders Parkwest Hospital, Knoxville, Tennessee, USA
Address reprint requests to Dr Grishkin, University Heart Surgeons, 1928 Alcoa Highway, Suite 300, Knoxville, TN 37920
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Abstract
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After an aneurysmal saphenous vein graft was ligated and divided at reoperation, the proximal stump continued to enlarge, rather than occluding by thrombosis, producing an aortic pseudoaneurysm that compressed adjacent cardiac structures. Oversewing the aortosaphenous junction of ligated vein graft remnants will prevent this complication.
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Introduction
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Aortic pseudoaneurysms can occur after cardiac operation at aortic cannulation sites, aortotomy suture lines, or saphenous vein graft anastmoses. This report describes a pseudoaneurysm that developed after ligation of a patent, but aneurysmal, saphenous vein graft, with progressive expansion of the vein graft remnant over the next 5 years.
A 70-year-old man had saphenous vein grafts placed to the left anterior descending (LAD), obtuse marginal (OMB), and right coronary (RCA) arteries in March 1982. The saphenous vein used was described as being of large caliber but not varicose. In February 1993, coronary arteriography showed aneurysmal changes and stenoses in the RCA vein graft, 90% stenosis in the LAD graft, and occlusion of the OMB graft. At reoperation the left internal thoracic artery (LITA) was placed to the LAD, and a new vein graft was placed sequentially to the posterior descending artery (PDA), ending on the OMB, with the new proximal anastamosis at the cardioplegia cannula site. The aneurysmal vein graft to the RCA was ligated and divided near its origin.
In April 1998, the patient was rehospitalized for a bleeding duodenal ulcer. A 1995 chest film had suggested only slight enlargement of the right heart border, but chest film on admission showed a large mass extending into the right hemithorax (Fig 1). Computerized tomographic scans suggested a pseudoaneurysm with compression of the right and left ventricle. Magnetic resonance imaging showed compression of the cardiac chambers and right hemidiaphragm (Fig 2), and suggested pseudoaneurysm formation with a jet originating from the aorta entering the mass, with layers of laminated clot within the mass. Coronary arteriography showed a jet of contrast extravasating from a site on the ascending aorta proximal to the origin of the sequential vein graft.
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Fig 2. Magnetic resonance imaging showing (A) the mass compressing the right diaphragm and displacing cardiac chambers to the left, with (B) a jet of blood entering the mass and extensive mural thrombus.
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The pseudoaneurysm was approached by a high right anterior thoracotomy incision using left femoral arterial and venous cardiopulmonary bypass. The mass was 15 cm in diameter, pulsatile, and adherent to the lung. The sequential vein graft was atherosclerotic and stretched across the anterior margin of the pseudoaneurysm. A separate superior vena cava cannula was inserted. After cooling to 32°C, the pseudoaneurysm was opened. Arterial bleeding was controlled by digital occlusion of the aortic origin and the laminated clot was extracted. The origin was a 5-mm oval defect in the lateral aortic wall with a remnant of old vein graft apparent at its margin. The defect appeared identical to the aperture created by an aortic punch for a proximal anastamotic site. There was no other evidence of the previous ligated aneurysmal vein graft. Circulatory arrest was induced for 5 minutes as the site was closed with pledgeted 3-0 and 4-0 polypropylene mattress sutures. The sequential vein graft adherent to the pseudoaneurysm wall required a vein interposition repair with the patient having no evidence of cardiac ischemia intraoperatively. The postoperative course was uncomplicated.
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Comment
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Saphenous vein grafts can develop pseudoaneurysms at proximal and distal anastamotic sites [1–3]. True aneurysmal changes in vein grafts can appear as medistinal masses on roentgenogram [4, 5], and late rupture of true vein graft aneurysms can also produce pseudoaneurysm [6]. In this case, a saphenous vein graft with aneurysmal changes had progressive expansion, rather than thrombosis, of the ligated proximal portion. By the law of LaPlace, (T = P x r/h) aneurysmal changes in the vein, by increasing the radius, (r) and decreasing vein wall thickness, (h) will facilitate subsequent expansion of the aneurysm if it remains exposed to distending arterial pressure (P).
During the next 5 years, there was eventual obliteration of any remnants of the vein graft wall, as successive layers of clot formed a pseudoaneurysm displacing adjacent cardiac structures.
When old vein grafts, especially those with aneurysmal change or varicosities, are abandoned at reoperation, we recommend oversewing the aortosaphenous junction to eliminate continued arterial pressure directed into the ligated vein graft stump, if the proximal anastamotic site is not used for the origin of a new vein graft. Closure of the aortosaphenous junction has been previously recommended to prevent aneurysmal change from developing in normal vein graft remnants following cardiac tranplantation [7]. Although unusual, aneurysmal or pseudoaneurysmal enlargement, rather than thrombosis, of ligated vein graft stumps, is a potentially life threatening but preventable complication of reoperative cardiac operation.
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References
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Sullivan K.L., Steiner R.M., Smullens S.N., Griska L., Meister S.G. Pseudoanerysm of the ascending aorta following cardiac surgery. Chest 1988;93:138-143.[Abstract/Free Full Text]
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Smith J.A., Goldstein J. Saphenous vein graft pseudoaneurysm formation after postoperative mediastinitis. Ann Thorac Surg 1992;54:766-768.[Abstract]
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Lopez-Velarde P., Hallman G.L., Treistman B. Aneurysm of an aortocoronary saphenous vein bypass graft presenting as an anterior mediastinal mass. Ann Thorac Surg 1988;46:349-350.[Abstract]
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Forster D.A., Haupert M.S. Large mediastinal mass secondary to an aortocoronary saphenous vein bypass graft aneurysm. Ann Thorac Surg 1991;52:547-548.[Abstract]
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Kallis P., Keogh B.E., Davies M.J. Pseudoaneurysm of aortocoronary vein graft secondary to late venous rupture. Case report and literature review. Br Heart J 1993;70:189-192.[Abstract/Free Full Text]
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Baldwin R.T., Klima T., Frazier O.H., Lonquist J., Radovancevic B. True aneurysm of the saphenous vein graft stump associated with CABG in a cardiac transplant patient. Ann Thorac Surg 1992;54:394-400.[Medline]
Accepted for publication May 28, 1999.
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Abstract
Introduction
