[High flow medullary venous malformation with aneurysm on the proximal artery--a case report]

Medullary Venous Malformation with an aneurysm is uncommon and only 4 cases have been reported in previous papers. We reported a case of a medullary venous malformation (MVM) of the frontal lobe with an aneurysm on its proximal artery. A 48 year old female with numbness of right fingers visited our hospital. On the CT scan, an abnormal enhanced area was found inside the left frontal lobe. The left carotid angiography showed both of an aneurysm around A com A in early arterial phase, and "MVM with early blush" in capillary-early venous phase. MRI showed linear signal void crossing the cortex to join paraventricular low intensity area (LIA) with slight cortical atrophy on sagittal slice. The CBF study by Xe-SPECT proved a high flow lesion, with mean CBF 69 (left), 59 (right) mg/100 g brain/min, Protective operation only for aneurysm was performed. The MVM in our case was proved to be a "high flow-low resistance system" by CBF study, although MVM has been considered a "low flow system". Reviewing papers, there were 3 cases of "high flow MVMs" confirmed by the measurement of CBF, all of them were large sized (greater than 4 cm) and with early blush angiographically. We conclude that large sized MVM with early blush needs hemodynamic inspection and special care to prevent "high flow MVMs" from hemorrhage and the steal.