硬膜動静脈奇形の臨床病態に関する検討

Dural arteriovenous malformations (dural AVMs) were reported sporadically. However, the diagnosis has become easier due to recent developments in clinical imaging modalities. It is known that dural AVMs present various signs and symptoms according to locations and/or specific pathophysiological conditions and occasionally cause serious neurological deficits with intracranial hemorrhage or venous infarction. There are few reports which describe the management of patients with dural AVMs. In this paper, clinical features of dural AVMs observed in our service are reviewed with special attention to angiographic findings.
Seventy-five cases of dural AVM treated between 1976 and 1995 were divided into two groups : 69 cases with single lesions and 6 cases with multiple lesions. The lesions were located in anterior fossa (AF), cavernous sinus (CS), transverse-sigmoid sinus (TS) or superior sagittal sinus (SSS). From their pathognomonic aspects, the cases were classified into two types : the apoplectic type (hemorrhage or venous infarction) and the non-apoplectic type (no evidence of hemorrhage or venous infarction).
Among 69 cases with single lesions, 8 involved the AF, 28 CS, 31 TS and 2 SSS. Patients of 60-69 years age predominated in our series. Males predominated in AF cases (M : F = 7 : 1), females in CS cases (M : F = 5 : 23). Among these, intracranial hemorrhages were noted in 5 AF, 1 CS, 11 TS and 2 SSS, respectively. On the other hand, venous infarctions were noted in 5 TS and 1 SSS. Twelve of 13 hemorrhagic cases exhibited intracerebral hematoma. The rate of apoplectic attacks by location was 63 % in the AF, 4 % in CS, 35 % in TS and 100 % in SSS, respectively. All cases of the apoplectic type demonstrated cortical venous reflux in the angiograms, whereas reflux was seen in only 7 (14 %) out of 50 non-apoplectic cases. Among the 19 apoplectic cases, 17 (89 %) showed the so-called isolated sinus, which was noted in only 4 (8 %) out of 50 non-apoplectic cases. A venous lake, meaning a dilated draining vein such as a saccular aneurysm of the vein, was also thought to be a warning sign of apoplexy.
Draining vessels were cut at proximal sites in 7 out of the 8 AF cases surgically and successfully. Most of the CS lesions were treated by embolization and/or radiation therapy, and the TS lesions by embolization or conservative method. No episode of rebleeding has occurred after treatment. Most of the patients had an excellent or good outcome, although 3 cases demonstrated a fair or poor outcome in the apoplectic group.
There were 6 cases (14 lesions) with multiple dural AVMs. However, 5 out of the 14 lesions caused apoplexy, all of these cases had an excellent or good outcome after treatment. There were 5 cases (83 %) of sinus thrombosis and 3 (50 %) of thrombosis in the deep vein of the legs, indicating that multiple dural AVMs may be associated with generalized thrombosis of the venous system.
In conclusion, if dural AVMs are associated with cortical venous reflux, isolated sinus and/or a venous lake angiographically, the lesions have a high risk of intracranical hemorrhage or venous infarction. Therefore, such patients need urgent treatment.