慢性硬膜下血腫手術中に発症した脳表仮性動脈瘤損傷による急性硬膜下血腫

抄録

We report a case of acute subdural hematoma (ASHD) that oc­curred due to damage to the pial artery pseudoaneurysm during burr hole drainage surgery for chronic subdural hematoma (CSDH). The patient was an 84–year–old male with recurrent bilateral CSDH, exhibiting a unique CT finding of adhesion between the outer and inner membranes of the hematoma on the left side. Burr hole drain­age surgery was performed for the CSDH, and acute bleeding occurred during drainage on the left side. A head CT scan revealed ASDH, and emergency craniotomy was performed for hematoma evacuation. Upon opening the dura mater, active bleed­ing was observed from a pial artery. Microscopic observation showed that the bleeding point was like a pseudoaneurysm, and hemostasis was achieved by clipping the bleeding point. Histopathological examination of the bleeding site tissue confirmed the possibility of a pseudoaneurysm. The cause of acute bleeding in this case was due to damage caused by the insertion of the drainage tube. The finding of adhesion between the outer and inner membranes of the hematoma may suggest adhesion of the arachnoid and pial arteries. Furthermore, the possibility of a pseudoaneurysm being formed cannot be ruled out in this case. We must take care of insert­ing a drainage tube, as it may damage blood vessels or pseudo­aneurysms and cause acute bleeding. Although a rare com­plication, awareness of its occurrence is clinically significant.