Dural arteriovenous fistulas (dAVFs) of an anterior cranial fossa are rare. Because of the high risk of intracranial hemorrhage and relatively easy access for direct surgery, aggressive treatment has been recommended. The natural history of anterior cranial fossa dAVFs (ACF dAVFs) is unclear in spite of many reports for the natural history of general dAVFs. To treat ACF dAVFs, direct surgery has traditionally been performed and endovascular surgery has recently been introduced. A 74-year-old man was transferred with severe consciousness disturbance and presented with devastating intracerebral hemorrhage on the CT scan. Digital subtraction angiography revealed the ACF dAVFs with a large venous pouch. The patient received direct surgery, nevertheless he became vegetative state. Later on, a smaller venous pouch was recognized on the CT scan when he had suffered from the thalamic hemorrhage sixteen months before. There are twelve cases including our case which was treated for a certain period and documented in detail. Eleven of twelve cases were asymptomatic. Three of the six cases with a venous pouch had some events possibly related to the disease, though none of the six cases without a venous pouch had any events during observation. In conclusion, an ACF dAVF with a venous pouch should be treated by direct surgery or endovascular surgery even if it is incidentally found. By contrast, careful observation might be a possible therapeutic option for an ACF dAVF without a venous pouch if there is mild reflux flow.
Dural arteriovenous fistulas (dAVFs) comprise approximately 10% - 15% of all intracranial arteriovenous malformations [
A 74-year-old man was transferred to our institute with severe impairment of consciousness. On admission, his Glasgow Coma Scale was 4 (E1V1M2) and he exhibited partial loss of brain stem reflexes. CT scan showed a large hematoma in the right frontal lobe with subdural and intraventricular hemorrhage. A more noteworthy finding was that suspicious vascular dilatation was located next to the intracerebral hematoma (
During angiography, his bilateral pupils were dilated. He immediately received right frontal craniotomy and evacuation of the hematoma. On opening the dura mater, the intracerebral hematoma penetrated the frontal lobe and arterial bleeding occurred. After removing the hematoma, it was obvious that his arterial bleeding was caused by a venous pouch. The venous pouch and the dilated drainer were occluded by electrocoagulation with obliteration of the fistula.
Later on, we had a chance to recheck the CT scan which had been taken 16 months previously when the patient had suffered from a right thalamic hemorrhage. It revealed that the existence of the venous pouch at the right anterior cranial fossa and that the pouch had been smaller than in the onset of the massive hemorrhage (
Dural arteriovenous fistulas (dAVFs) of an anterior cranial fossa have several clinical characteristics. They are relatively rare, and have a male predominance (80% - 85%) [
As for general dAVFs, Awad et al. reported that leptomeningeal venous drainage, venous pouch, and galenic drainage correlated significantly (p < 0.05) with aggressive neurological presentation [
The natural history of an anterior cranial fossa (ACF) dAVF is not fully understood because direct surgery have been strongly recommended due to the high risk of bleeding and relatively easy access to disconnect the fistula [
In our case, the patients had developed a thalamic hemorrhage and a venous pouch had unfortunately been overlooked, finally bleeding from the venous pouch resulted in serious neurological deficits. The draining pial vein flowed into the superior sagittal sinus, not the cavernous sinus or other deep venous systems. Therefore, his ACF dAVF was considered to be no relation to the thalamic hemorrhage and asymptomatic at the time.
It is well known that direct surgery to disconnect the fistula near a cribriform plate is sufficient and relatively safe. Because of less morbidity of direct surgery and poor outcome after bleeding, direct surgery has been strongly recommended. Until recently, transarterial embolization via the ophthalmic artery or transvenous embolization via draining vein independent of sinuses was at risk of retinal ischemic complications or very difficult to
Case | Author, Year | Age/Sex | Symptom | Feeder | Draining System | VP | FU | Event | GOS |
---|---|---|---|---|---|---|---|---|---|
1 | Bitoh, 1981 | 61/M | (-) | ECA | CV→SSS | (+) | 4 mo | op | MD |
2 | Yamasaki, 1995 | 76/M | (-) | EA > ECA | CV→SSS | (+) | 1 y | censored | GR |
3 | Ishikawa, 1997 | 65/M | (-) | EA | CV→SSS | (-) | 5 y | op | GR |
4 | Im, 2004 | 68/M | (-) | ECA | CV→SSS | (+), small | 7 y | Enlargement of VP | GR |
5 | Jamous, 2004 | 47/M | small ICH | EA | CV→SSS | (-) | 10 y | censored | GR |
6 | 71/M | (-) | EA | CV→SSS | (-) | 2 y | censored | GR | |
7 | 60/M | (-) | EA | CV→SSS | (-) | 3 y | censored | GR | |
8 | Murakami, 2005 | 52/M | (-) | EA | CV→SSS | (-) | 3 y | censored | GR |
9 | Deshmukh, 2005 | 50/M | (-) | EA | CV→SSS | (-) | 6 mo | op | GR |
10 | Hashiguchi, 2007 | 67/M | (-) | ECA > EA | CV→CS | (+) | 4 y | ICH | SD |
11 | Tanei, 2008 | 63/M | (-) | EA | CV→SSS | (+), small | 3 y | censored | GR |
12 | Present case, 2015 | 74/M | (-) | EA > ECA | CV→SSS | (+) | 16 mo | ICH | VS |
VP: venous pouch; FU: follow up period; GOS: Glasgow Outcome Scale; M: male; ICH: intracerebral hemorrhage; ECA: external carotid artery; EA: ethomoidal artery; CV: cortical vein; SSS: superior sagittal sinus; CS: cavernous sinus; mo: month; y: year; op: operation; MD: moderate disability; GR: good recovery; SD: severe disability; VS: vegetative state.
access. There are several successful reports of transarterial or transvenous embolization for the ACF dAVFs [
For an ACF dAVF with a venous pouch, direct surgery or endovascular surgery must be considered regardless of whether symptoms are present or not because of the high risk of bleeding. But for an ACF dAVF without a venous pouch, therapeutic decision making should be based on radiological findings since Cognard Type III ACF dAVF might be less dangerous.
We experienced the case of the anterior cranial fossa dural arteriovenous fistula (ACF dAVF) which resulted in vegetative state because its venous pouch had been overlooked. By reviewing the literature, it is clarified that an ACF dAVF with a venous pouch (Cognard type IV) should be treated by direct surgery or endovascular surgery as previously believed even if it is incidentally found. Conversely, careful observation might be one possible therapeutic option for an anterior cranial fossa dAVF without a venous pouch (Cognard type III) in the case of mild reflux flow. In conclusion, it is important to circumspectly decide the strategy for ACF dAVFs with consideration of the symptoms, the existence of a venous pouch, and the amount of venous reflux.
The authors declare that they have no conflict of interest and have signed informed consent forms from the patient’s relatives before submitting to the Open Journal of Modern Neurosurgery.