Two Difficult Cases of Coil Retrieval during Aneurysm Embolization

We experienced two difficult cases of coil retrieval during aneurysm embolization using Guglielmi detachable coils. In the first case, one coil was caught by the other coil and a microcatheter at the tip of it. When a microcatheter which has a hard shaft is put into a tightly packed coil mesh and the coil is pushed forcefully, it may return into the microcatheter again and capture another one. In the second case, a knot in the coil was formed during embolization while using the remodeling technique. When the tip of the coil crosses the next loop and is trapped between the balloon and the blood vessel wall, a knot may form if it is pulled in that situation. In intracranial aneurysm embolization, detachment of the first coil or manipulation near the neck of the aneurysm in the last stage of embolization are very important. Therefore, the risk of trouble with the coil at those times, possibly leading to a fatal complication, is very high. We hope that safer treatment will be carried out by through knowledge of such rare cases.