A Guglielmi Detachable Coil, or GDC, is a platinum coil commonly used in intracranial non-invasive surgery for the occlusion of brain aneurysms. It was invented by Italian interventional neuroradiologist Dr. Guido Guglielmi in 1990, and was gradually introduced in the later 1990s as an alternative to surgical clipping, which requires invasive surgery.
The peculiarities of this coil lie in its physical as well as its electrolytical properties: The material has a high memory effect, allowing it to easily bend and regain its original coil shape. It is also highly sensitive to low currents, which allow the GDC to detach from the catheter that carries it, thus receiving the name of "detachable coil".
The long-term efficacy of GDC coils and similar coils in the treatment of cerebral aneurysms is still being studied.