[Superselective angiographic findings of ipsilateral middle meningeal artery of chronic subdural hematoma in adults].

The authors reported the results of continuous superselective angiography of the ipsilateral middle meningeal artery (MMA) in cases of chronic subdural hematoma (CSH) in adults. MMA angiography was performed twice, at an interval of approximately two weeks, in 3 cases of conservative and 1 case of surgical treatment. The features of MMA angiographic findings were diffuse dilatation of MMA and visualization of scattered abnormal vascular networks (VN), which seemed to be macrocapillaries in the outer membrane of the CSH. In two out of the three cases of conservative treatment, these VN revealed a dynamic change temporarily and spatially, i.e. either enlargement or reduction. In one case with a long clinical course a stable MMA angiogram was seen. The operated case showed dramatic change on the second (postoperative) MMA angiogram. The VN around burr hole portion was huge and dark, and several newly visualized small arteries penetrated the enlarged VN, which was thought to have been caused by the operation. The mean blood pressure in the MMA was 103 mmHg. The reason for the acute enlargement of the CSH might be explained as arterial bleeding into the hematoma cavity, caused by rupture of thin walled macrocapillaries by direct arterial pressure.