[Ectopic internal carotid artery in the tympanic cavity. Intraoperative complications and their treatment. A case report].
Ectopy of the internal carotid artery involving the middle ear occurs only rarely. In this case, middle ear surgery will almost always result in severe haemorrhage. After package of the external auditory canal and the epipharynx, immediate closure or ligation of the internal carotid artery is mandatory. The authors describe the interventional neuroradiological treatment as an alternative way to the known neurosurgical methods like cervical and intracranial ligation of the artery. Intravasal blocking of the leakage was done by using a detachable balloon filled with contrast medium. During this procedure cortical evoked potentials were measured showing no decrease of the homolateral haemispheric blood flow. Although this procedure cannot maintain the continuity of the internal carotid artery, it preserves a maximum of collateral vessels. The cortical evoked potentials simultaneously show the brain function during blockage of the artery.