Giant Dissecting Aneurysm of the Internal Carotid Artery in a 35-Year-Old Patient: A Case Report.

Giant dissecting aneurysms of the internal carotid artery are extremely uncommon, particularly in young adults. In this report, we provide a case of a 35-year-old male patient who experienced severe headaches, double vision, paralysis of the left abducens nerve, trigeminal neuralgia, nausea, and vomiting. The cerebral MRI showed an intensely gadolinophilic lesion following the left internal carotid artery route from the petrous canal; it also caused an internal deviation of the cavernous route of the internal carotid artery with a fluid heterogeneous area that pushed the cavernous dura mater (including the Gasser ganglion) on the free cisternal route of the trigeminal nerve. Furthermore, the cerebral angiography revealed a giant dissecting aneurysm at the C2-C4 junction of ICA, anteriorly oriented with perilesional stenoses. The interdisciplinary medical team determined that the most optimal therapeutic strategy would involve coil embolization, and the giant left ICA aneurysm was occluded along with the left ICA, with 15 giant platinum coils. Following the successful intervention, the patient experienced a remarkable clinical outcome, characterized by an immediate reversal of the majority of the symptoms. Although we were not certain of the alleviation of symptoms after the endovascular treatment, fortunately, the results were beyond expectations.