[Intracranial hemorrhage associated with injury of the critical diploic venous system in clipping for unruptured cerebral aneurysm: a case report].

A case of intracranial hemorrhage associated with injury of a critical diploic venous system in clipping for an unruptured cerebral aneurysm was reported. A 67-year-old female presented with a sense of floating. Magnetic resonance angiography (MRA) showed a C1-2 portion aneurysm of the left internal carotid artery 13 mm in size projecting supero-laterally. Three-dimensional CT angiography (3DCTA) volume rendering revealed a developed left fronto-anterior temporal diploic venous system draining the frontal cortical venous return. Because of the large and wide-necked aneurysm, we planned clipping surgery for the purpose of a complete cure. The operation was performed with left fronto-temporal craniotomy at the expense of the diploic venous system. Using techniques such as bipolar coagulation and suction decompression, neck clipping was accomplished via the distal trans-sylvian approach. After the operation, the patient was noticed to be delirious, and post-operative CT demonstrated intracranial hemorrhage in the left frontal lobe with severe brain edema. Motor aphasia was remarkable, but it was gradually relieved, and she left our hospital with no motor weakness. 3 months after the operation, her aphasia was faintly perceptible but she could live independently. We concluded that the injury of a diploic venous system could cause intracranial hemorrhage with intractable brain edema by critically interrupting the frontal venous return.