外科的手術単独で治療し得た海綿静脈洞部洞外硬膜動静脈瘻の1例

Successful Surgical Treatment of an Extrasinusal Dural Arteriovenous Fistula Located in the Lateral Wall of the Cavernous Sinus: A Case Report

Ⅰ．はじめに

　頭蓋内硬膜動静脈瘻に対する治療においては，近年の血管内治療の発達とともに外科的手術の対象となる症例は減少している．その中でも海綿静脈洞に発生する硬膜動静脈瘻に対しては，ほとんどの症例が血管内治療単独で治療されているのが現状である．しかし，前頭蓋底硬膜動静脈瘻に代表されるように，外科的手術による硬膜内流入部での流出静脈遮断により根治し得る動静脈瘻も存在する．今回，われわれは海綿静脈洞外壁にシャント形成を認め，直接，浅中大脳静脈に逆流し，蝶形骨縁近傍に静脈瘤を合併したhigh flow typeの硬膜動静脈瘻に対して，外科的手術単独で病変の消失を認めた症例を経験した．これまでに，海綿静脈洞における本例同様の灌流形式を示した硬膜動静脈瘻に対して，外科的手術単独で治療し得た例は，われわれが過去の報告を渉猟し得た限りではほとんどなく，若干の文献的考察を加えて報告する．

　We report the successful surgical treatment of a dural arteriovenous fistula（AVF）located in the lateral wall of the cavernous sinus. A 44-year-old woman presented with facial numbness in the left V3 area. Magnetic resonance imaging showed a flow void sign around the sphenoid ridge on a T2-weighted image. Digital subtraction angiography（DSA）demonstrated a dural AVF that was supplied by feeding arteries from the C4 portion of the left internal carotid artery. Without sinus enhancement, the draining vein flowed directly through the superficial sylvian vein into the vein of Labbé. Following treatment of the dural AVF located in the anterior cranial fossa, we ligated the draining vein at the penetrating point in the intradural region using surgical management. Intraoperative findings showed that the shunt point was located in the left lateral wall of the cavernous sinus. The postoperative course was uneventful and DSA showed no evidence of the AVF. The patient was discharged with no neurological deficits. Few studies have reported the use of direct surgery alone for the treatment of dural AVFs located in the cavernous sinus with a perfusion pattern as in this case.