Endovascular neurosurgery, also known as interventional neuroradiology (INR) and endovascular surgical neuroradiology (ESNR) is brain surgery performed from inside blood vessels. Doctors thread catheters through blood vessels, pass tiny instruments through the catheters and use those instruments to conduct the procedures.

Most endovascular procedures require only a small incision in the skin over the femoral artery in the leg to access a major blood vessel and insert the catheters. This makes endovascular neurosurgery a form of minimally invasive surgery—typically less painful and allowing for shorter recovery time than traditional surgery.