A Case of Cavernous Sinus Fistula Caused by Ruptured Spontaneous Aneurysm on Persistent Primitive Trigeminal Artery

The most frequent of the embryonic persistent arteries that connect the internal carotid artery to the posterior circulation is the persistent primitive trigeminal artery (PPTA), which is recognized on 0.1%-0.6% on the basis of conventional angiography or magnetic resonance imaging (MRI). It is usually asymptomatic; however, in rare cases, symptoms of cerebral neuropathy or vascular disease may take place. The patient was a 50-year-old woman who had a history of dyslipidemia and no history of trauma. After a visit to her local doctor, she was referred to us with complaints of mild headache and unilateral tinnitus. MRI revealed a cavernous sinus fistula. She had temporary symptom relief, but ipsilateral ocular symptoms appeared eventually and extended to the contralateral side. Through cerebral angiography, a direct cavernous sinus fistula due to a ruptured PPTA trunk aneurysm was revealed. Coil embolization was carried out via PPTA. The PPTA aneurysm was partially embolized from within the venous sinus using a fistula. The aneurysm and cavernous sinus fistula disappeared without transvenous embolization while preserving the PPTA. Although reports on the treatment of PPTA aneurysms have been numerous already, this report describes a unique case in which a ruptured spontaneous aneurysm on the PPTA trunk resulted in a cavernous sinus fistula, which was treated successfully.