錐体テント部硬膜動静脈奇形に対する導出静脈（洞）閉塞術

Surgical Interruption of Draining Vein or Dural Sinus : treatment for petrotentorial dural arteriovenous malformation

I．はじめに

　硬膜動静脈奇形は頭蓋内動静脈奇形の10-15％にすぎず，比較的まれな疾患である^1,2）．これまで，さまざまな治療が試みられてきたが，最近では外科的治療には余り注目されず，血管内手術を選択することが一般的である^2,12,13）．しかし，経動脈的血管内塞栓術のみでは再発が多く，治癒率は50％とされ^15,16），静脈洞を含めた硬膜動静脈奇形の摘出術はSundtら^17）によって5％のmajormorbididy and mortalityがあることが報告されている．このようなことから，経静脈的血管内塞栓術が好んで選択される傾向にある．しかし，経静脈的塞栓術が技術的に困難であったり，静脈洞の閉塞や奇形のため経静脈的アプローチが不可能な症例がある^14,16,21）．今回，著者らは血管内手術で治癒せしめることができなかった3例の錐体テント部硬膜動静脈奇形に対して摘出術よりも外科的侵襲性の低い導出静脈（洞）閉塞術（draining veinclipping）を施行し，満足すべき結果を得た．本手術法の適応，術前血管内栓塞術の役割，術中モニターリング，手術の実際について検討を加えたので報告する．

The authors report three cases with petrotentorial dural arteriovenous malformation who underwent sur-gical interruption of the draining vein or dural sinus. They discuss the rationale and feasibility of this sur-gical procedure. Case 1 (70-year-old man) presented with trigeminal neuralgia and cerebellar ataxia causedby subarachnoid and cerebellar hemorrhage. Case 2 (68-year-old man) with trigeminal neuralgia due tovenous mass effect. Case 3 (48-year-old man) with dementia caused by venous ischemia in the bilateralthalami. Cases 1 and 2 underwent lateral suboccipital craniotomy followed by infratentorial supracerebellarapproach, and the draining vein was interrupted by aneurysmal clip under the cerebellar tentorium. Case 3underwent surgical occlusion of the straight sinus by occipital transfalcine transtentorial approach aftertransarterial embolization had failed. Intraoperative digital subtraction angiography revealed the disappear-ance of dural AVMs in all three cases. The clinical symptoms disappeared postoperatively, and follow-up6-vessel-angiography 2, 20, 11 months later, respectively, revealed no recurrence of dural AVMs.

It has recently been proposed that many cranial dural AVMs with leptomeningeal venous drainage re-quire only interruption of the draining vein as it enters the subarachnoid space for successful, lasting eli-mination. The striking clinical and radiological improvement in these cases emphasizes the pivotal role ofsurgical occlusion of the draining vein for petrotentorial dural AVMs which are not amenable to cure byendovascular procedures.