Saturday, May 19, 2012

Cerebral Bypasses for Complex Aneurysms and Tumors: Long-term Results and Graft Management Strategi

BACKGROUND: Various techniques of cerebral bypasses are used to treat aneurysms and tumors. OBJECTIVE: To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems. METHODS: A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied. RESULTS: A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1). CONCLUSION: The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis. ABBREVIATIONS: CTA, computed tomographic angiogram EC-IC, extracranial to intracranial bypass HF, high flow IADSA, intra-arterial digital subtraction angiogram IC-IC, intracranial to intracranial bypass ICA, internal carotid artery LF, low flow MCA, middle cerebral artery mRS, modified Rankin Scale OA, occipital artery PCA, posterior cerebral artery PCOM, posterior communicating artery PICA, posterior inferior cerebellar artery RAG, radial artery graft STA, superficial temporal artery SVG, saphenous vein graft TIA, transient ischemic attack





No comments:

Post a Comment