Ahead of Print: Cerebral Bypasses for Complex Aneurysms and Tumors

Background: Various techniques of cerebral bypasses are used in the treatment of aneurysms and tumors.

Objective: To study long-term clinical and radiological outcome of various bypass types, and analyze techniques used in the management of long-term graft problems.

Methods: A consecutive series of patients who underwent revascularization during a five-year period was 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 aneurysms and 11 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 and 6 short} and 20 local bypasses], with mean radiological follow-up of 32 months (range 1-53). At late follow-up, 5 of 9 (56%) IC-IC (5 short and none of the long grafts), 8 of 9 (90%) EC-IC LF and 44 of 48 (92%) EC-IC (HF), and all local bypasses were patent. Four patients with EC-IC (HF) bypass occlusions were asymptomatic, but TIAs were noted in 3/6 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: EC-IC and local bypasses have higher long-term patency rates (91% and 100 %) compared to 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.

From: Cerebral Bypasses for Complex Aneurysms and Tumors: Long-Term Results and Graft Management Strategies by Ramanathan et al.

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