[Dura arteriovenous malformation of the posterior fossa-clinical and angiographical analysis of 6 cases].

Dural arteriovenous malformation of the posterior fossa was infrequently reported in the literatures. We presented 6 cases of dural arteriovenous malformation of the posterior fossa with the presentation of typical examples. Up to the end February, 1974, 119 cases of intracranial arteriovenous malformation were experienced in our clinic, in which there were 6 cases of dural arteriovenous malformation. The ages of our series ranged from 41 to 75 years old and 57 years old in average. Tinnitus and headache were two main symptoms which developed in most of the cases. As for the older symptoms, visual disturbance was seen in 4 cases, unilateral pulsating exophthalmos in 1 case and papilledema in 3 cases. There wers two cases which progressive dementia was developed by the cerebral anoxia due to arteriovenous shung. On examination, a pulsatile bruit was audible at the mastoid region in all cases and a thrill could be palpated along the occipital arteries. Many kinds of durl and/or tentorial arteries which were drained directly into the sinuses at the occipital portion as the feeding arteries were visualized angiographically. Moreover, the angiographical patterns of feeding arteries into the sinuses showed dynamic changes after the operation. As for the treatments, many kinds of surgery were carried out for the cases by the combination method of the next 6 ways. 1. ligation of external carotid artery 2. ablation of periosteum from occipital bone 3. occipital and/or suboccipital craniectomy 4. clipping of almost of all feeding arteries at dura mater and tentorium 5. ligation of threocervical trunk 6. ventriculo-atrial shunt or ventriculo-peritoneal shunt From our experiences, the most effective treatment is thought to be a direct closure of intradural arteriovenous shunt near the sinus at the occipital portion in the early stage.