Emerging subspecialties in neurology: endovascular surgical neuroradiology.

Michael Chen, MD Thanh Nguyen, MD In 1998, the World Federation of Interventional and Therapeutic Neuroradiology published fellowship guidelines for interventional neuroradiology (INR), specifying requirements for trainees with backgrounds in either neuroradiology or neurosurgery.1 In 2006, the Accreditation Council for Graduate Medical Education (ACGME) announced the revised program requirements in the United States for fellowship education in endovascular surgical neuroradiology (ESN). ESN was not only to be the new name in the United States for what was previously called interventional neuroradiology, but trainees with a neurology background were also included.2 ESN is defined by the ACGME as a clinical subspecialty for the diagnosis and treatment of neurovascular diseases using x-ray fluoroscopy and angiography. Devices designed for the treatment of intracranial cerebral aneurysms, cerebral arteriovenous malformations, head and neck tumors, acute stroke, and intracranial stenosis have all gained Food and Drug Administration approval at varying levels, each with specific indications for therapy in the brain, head, neck, and spinal cord. Devices designed for extracranial and intracranial use include microcatheters, microguidewires, detachable coils, particulate and liquid embolic materials, clot retriever devices, stents, and balloons. Treatment options in interventional neuroradiology familiar to neurologists include extracranial and intracranial carotid revascularization and acute intraarterial thrombolysis (chemical or mechanical) for stroke. In recent years, there has been a greater awareness, development, and understanding of these treatment options, leading more neurologists to adopt an aggressive approach in consulting their neurointerventional colleagues. In addition, the evolution of the field has led some neurologists to pursue the necessary additional training to perform these procedures.