Controlled detachment coils (now known as Guglielmi Detachable Coils) were introduced in the 1980s by the neurosurgeon Guido Guglielmi, as an alternative to the endovascular treatment of cerebral aneurysms.

It is a platinum-tungsten alloy coil attached to a stainless steel release guide wire. These coils are released into the aneurysm via a micro-catheter that is inserted through the femoral artery of the leg and gently advanced to the brain. The micro-catheter is advanced into the aneurysm itself, and the coils are then released sequentially.

Once the coils are released into the aneurysm, the blood flow inside the aneurysm is impaired and slowed down, which leads to thrombosis of the aneurysm and therefore its embolization.