Vascular surgery is a specialty of surgery in which diseases of the vascular system, or arteries and veins, are managed by medical therapy, minimally-invasive catheter procedures, and surgical reconstruction. The specialty evolved from general and cardiac surgery as well as minimally invasive techniques pioneered by interventional radiology. The vascular surgeon is trained in the diagnosis and management of diseases affecting all parts of the vascular system except that of the heart and brain. Cardiothoracic surgeons manage surgical disease of the heart and its vessels. Neurosurgeons and interventional neuroradiologists manage surgical disease of the vessels in the brain (e.g., intracranial aneurysms).