中大脳動脈皮質枝分枝の破綻と関連した再発慢性硬膜下血腫の1例 : 内膜内洞様血管の組織学的検討  [in Japanese] An Unusual Recurrent Chronic Subdural Hematoma related to the Rupture of Cortical Branch of the Middle Cerebral Artery : Histological Examination of the Inner Membrane around the Cortical Arteries  [in Japanese]

穿頭洗浄術後11日目にCT上,慢性硬膜下血腫の再発をきたした36歳男性に開頭術を施行した症例を報告した.術中,内膜を貫通する中大脳動脈皮質枝由来の細動脈が確認された.本血管周囲の内膜を組織学的に検査したところ,多数の赤血球を含む洞様血管層が存在し,その一部は破綻し小血腫が内膜線維層を穿破し血腫内腔に連続していた.本例はこく薄い急性硬膜下血腫から移行した慢性硬膜下血腫と考えられ,再出血の原因の大部分は外膜内の洞様血管の破綻によるものであるが,通常の慢性硬膜下血腫と異なり皮質動脈分枝周辺の内膜組織には外膜と同様の変化が存在した。急性硬膜下血腫からの移行例にはこのような所見が観察されるため,再増悪時の治療には外膜同様内膜側の洞様血管の存在も考慮する必要がある.

We report a case of recurrent chronic subdural hematoma initially treated by a burr-hole opening with irrigation. A 36-year-old man experienced headache about a month after head injury, which was diagnosed as a chronic subdural hematoma. He underwent burr-hole irrigation and the postoperative course was uneventful. A CT scan taken seven days after the operation revealed no residual subdural hematoma. And so he was discharged from hospital without neurological deficits. Four days after his discharge, he came to the hospital with a severe headache, and a CT scan demonstrated a recurrent chronic subdural hematoma. This time, we performed a craniotomy in order to investigate the cause of the recurrence. Right frontotemporoparietal craniotomy was performed, and an abnormal small artery arising from the cortical branch of the middle cerebral artery, which penetrated into the inner membrane of the chronic subdural hematoma, was confirmed. Pathological examination of the inner membrane adjacent to the abnormal small artery showed plenty of macrocapillaries in the sinusoidal channel layer, which were filled with red blood cells. Some of the macrocapillaries had ruptured, and so hematoma was noted in the sinusoidal channel layer and in the cavity of the hematoma, which had broken the fibrous layer. These findings suggest that a thin acute subdural hematoma was initially formed under the rupture of the cortical artery and changed into an unusual chronic subdural hematoma. And the re-growth of the subdural hematoma resulted mostly from the macrocapillaries of the outer membrane and partly from that of the inner membrane. So when we face such cases, we had better consider both the macrocapillaries of the outer and inner membranes before we choose the method of operation to avoid this type of the recurrence.