Giant aneurysms and bypass surgery

Giant aneurysms are among the most challenging neurovascular lesions with poor natural history. Therefore, treatment to minimize morbidity and mortality is paramount. With development in skull base approaches, microsurgical techniques, endovascular technology, and neuroanaesthesia, a proportion of giant aneurysms can be clipped primarily, clip reconstructed, or treated endovascularly. With the ongoing development in endovascular techniques, more of these lesions can be treated successfully without open surgery. However, without long-term data on endovascular reconstruction, aneurysm recurrence after coiling, and poor outcomes with the use of flow diverters for dolichoectatic basilar aneurysms, surgical treatment remains a viable option for patients with these complex lesions. This chapter discusses the use of complex revascularization and flow reversal techniques including high-flow extracranial to intracranial bypass for these patients.