Bypass surgery for brain aneurysms in the era of flow diverters
Kevin Shah, Timothy White, Amir Dehdashti
Introduction: Advancements in neuroendovascular surgery with the revolution of flow diverting stents have led to significant decrease in indications for microvascular bypass.
Objective: The purpose of this study was to evaluate the indication and outcomes of cerebral revascularization for brain aneurysms over the past 10 years.
Methods: We reviewed 121 patients who had undergone cerebral bypass. Twenty-nine patients with at least 1 year follow up who underwent bypass for aneurysm treatment were identified.
Results: Indications for surgery were giant/very large aneurysm in 15, blister aneurysm in 3, fusiform aneurysm in 10 and an unusual basilar tip aneurysm in 1 patient. Eight patients underwent combined endovascular and bypass treatment. Immediate aneurysm occlusion was achieved in 25 patients and 4 were treated with retrograde flow strategy. Immediate bypass patency was achieved in 27(93%). Immediate postoperative new deficit was observed in 4(14%). At one year, 26 patients were available for clinical and radiological follow-up. The bypass patency was confirmed in 24(92%). The two patients with occluded bypass did not have new stroke. Two of the aneurysms needed additional treatment at longer term follow-up. The outcome at one year was MRS 0-2 in 21, MRS 3 in 4, MRS 4 in 1 and mortality in 3 patients. Eighteen patients have follow-ups beyond three years with no evidence of stroke or aneurysm recurrence.
Conclusions: There is a small subset of patients with brain aneurysm who need cerebral revascularization. While the surgery carries a significant risk of stroke or major neurological deficit, the bypass remains a vital component in the armamentarium of cerebrovascular surgeons.