後下小脳動脈解離性動脈瘤の治療戦略

Therapeutic Strategy for Isolated Dissecting Aneurysms of the Posterior Inferior Cerebellar Artery： Report of Three Cases and Review of Literature

Ⅰ．は じ め に

　解離性動脈瘤が後下小脳動脈に限局して発生することは稀である¹⁵⁾．そのため自然経過や治療法についても一定の見解は得られていない²³⁾．当施設で経験した3例に，過去に報告された症例を加え，後下小脳動脈に限局した解離性動脈瘤の病態と治療戦略について検討した．

　Dissecting aneurysm of the posterior inferior cerebellar artery (PICA) is a relatively rare disease and its treatment has not been well established. The authors analyzed the clinical and anatomical features of 38 reported lesions and three of our cases to clarify the “best therapeutic modality”. The average age was 45.0 years old and 27 patients were male. Left-sided predominance (26 cases) was noted. As to the mode of onset,23 cases were subarachnoid hemorrhage,16 were ischemia,and 6 were Wallenberg's syndrome. Anatomically,the sites of dissection were located in the proximal segment of PICA in 31 lesions (75.6％). Review of the cases show that 30 (75％) patients underwent surgical therapy,and 7 (17.5％) patients underwent endovascular treatment. Twenty six patients who took surgical therapy and 5 patients who took endovascular treatment had excellent or good outcome. The critical point in therapeutic procedure is the preservation of perforating branches arising from PICA,therefore surgical trapping with the revascularization of PICA (usually extracranial-PICA anastomosis),in which these tiny branches are secured under microscopic manipulation,has the advantage in principle.