Basic Aspects of High-Flow Extracranial-Intracranial Bypass

Abstract

This article is the second of two parts. Cerebral revascularization procedures regained popularity during the past few years. They have been used routinely to treat patientswith giant unclippable aneurysms and complex cranial base lesions. Furthermore, recent evidence has shown that a specific group of patients with ischemic cerebrovascular disease could benefit from low-flow or highflow bypass. Improvement in surgical techniques, with consequent decrease in morbidity and mortality associated with high-flowbypass for giant unclippable aneurysms, revitalized the question as to whether patients with indications for internal carotid artery (ICA) occlusion should be universally revascularized. Part I of this article discussed patient selection and surgical technique for extracranial-intracranial (EC-IC) bypass. In part II, we discuss graft selection and a universal versus selective revascularization approach.After reading this article, the neurosurgeon should be able to describe how to choose appropriate grafts for patients undergoing extracranial-intracranial bypass and explain the benefits and risks associated with use of a universal versus selective revascularization approach. The development of EC-IC bypasswas subsequent to the application of surgical microscope to neurosurgery. In 1962, Julius Jacobson (a general vascular surgeon) and Donaghy were the first to describe a microsurgical procedure in neurosurgery. In 1965, Yasargil went to study at Donaghy’s laboratory in Vermont. Their diligent work improved the pioneering bypass techniques of Suarez and Jacobson. In 1972, Yasargil performed the first superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in a patientwith moyamoya disease.Meanwhile, many other neurosurgeons were developing alternative bypass techniques. In the 1970s, Sundt and Ausman introduced posterior circulation revascularization. Lougheedwas the first to use a great saphenous vein (GSV) in an EC-IC bypass, followed byAusman in 1978, who used a radial artery (RA) graft. Since then, much of the technique has improved as have anesthetic techniques, ICU Basic Aspects of High-Flow Extracranial-Intracranial Bypass: Part II