**1. Introduction**

Endovascular neurosurgery is now the most commonly practiced therapeutic approach for most vascular lesions involving the brain and spinal cord [1]. At the beginning, balloons are the only available techniques; latter coils, embolic agents, and stents are introduced [2]. With expansion of the endovascular devices and techniques, the treatment strategies for cerebrospinal vascular diseases has been refined [3]. Neurosurgeons must have the mindset to embrace and nurture the progress and technologic advances. The pioneers of endovascular neurosurgery considered the impossible and tenaciously stood by their dreams [4]. Their revolutionary ideas and inventions truly reflected their courage, faith, and determination. The shift away from open surgical approaches has had far-reaching implications for how we train neurosurgical residents and fellows and how we certify these individuals once their training is completed [5]. With the maturity of endovascular neurosurgery technology, we need to re-examine the resident and fellow training for neurovascular surgery. This chapter traces the evolution of endovascular neurosurgery and its current role as the dominant and frequently standard therapy for cerebral and spinal vascular diseases.
