Objective In this case report we describe a successful interdisciplinary approach (including flow redirection and endovascular occlusion) applied to a patient with a continuously growing extracranial giant aneurysm of the right internal carotid artery (ICA) due to known Ehlers–Danlos syndrome.

Case presentation A 42-year-old man with a continuously growing extracranial giant aneurysm of the right ICA sought treatment after failed surgery of a similar lesion of the left ICA. A multidisciplinary consultation was held at the end of 2008.

Treatment strategy The treatment strategy consisted of flow redirection in order to secure sufficient cerebral perfusion prior to surgical trapping of the carotid aneurysm. Flow redirection was achieved by placement of a double-barrel extracranial–intracranial bypass. Subsequent surgical trapping failed due to the extreme size of the aneurysm, making certain identification of surrounding structures impossible. The aneurysm was then successfully occluded by neuroradiological intervention. In a further procedure, a large intra-aneurysmal hematoma was surgically removed to reduce the remaining bulging aneurysm sac.

Conclusions This case report describes a successful interdisciplinary approach for the treatment of a rare giant extracranial ICA aneurysm in a patient with Ehlers–Danlos syndrome. Treatment options for this type are few and carry high risks. Flow redirection via extracranial–intracranial bypass followed by endovascular occlusion appears to be a good treatment approach.