未破裂脳動脈瘤の易破裂性の検討 : 未破裂脳動脈瘤の治療検討  [in Japanese] Unruptured Aneurysm with Higher Potential Risk of Bleeding  [in Japanese]

画像の進歩に伴い未破裂脳動脈瘤の検出が高くなると同時にその治療に関しても関心が高まってきている. また70歳代の高齢者の未破裂脳動脈瘤破裂もけっして少なくない. これらの観点より未破裂動脈瘤の易破裂性のファクターの模索に関してはその関心度が高く, 結論が早急に待たれるところである. 今回われわれの経験した過去3年の未破裂脳動脈瘤383例をもとに画像および病理学的検討から動脈瘤の易破裂性について若干の検討を加えたので報告する. 対象および方法 1999年1月から2002年12月までに治療した未破裂脳動脈瘤は383例でそのうちcoil塞栓術が64例である. 治療適応は年齢, 動脈瘤のサイズ, 部位, blebの有無, 危険因子(高血圧, 高脂血症, 喫煙), くも膜下出血の既往, 家族歴で決定した. 動脈瘤のサイズは径5mm以上とし, ただし形状の不整なもの明らかなblebを有する例は径3mmから治療した. 直達手術およびコイル塞栓術の治療の振り分けは, 直達手術例としたものは年齢70歳未満で, ただし前交通動脈瘤で高位, 後方向き, 中大脳動脈瘤の高位, 後方向きのものIC2/3, posterior circulationは原則として塞栓術を第一選択とした.

Subarachnoid hemorrhage is the most devastating clinical presentation of intracranial aneurysms, which makes it desirable to treat them before they bleed. Because this apoplectic event leaves most survivors with neurological deficits, we aim to define high-risk criteria for rupture based on our series. We retrospectively analyzed 383 cases of treated unruptured aneurysms between January 1999 and December 2002, sixty-four of whom received coil embolization. Treatment indications were previous SAH, presence of bleb, symptomatic aneurysms, size more than 5 mm, posterior circulation, irregular dome wall and high-amplitude bleb-site pulsatility on 4D-CTA. Intraoperative aneurysm wall resection was performed and histological examination done. The outcome was good in all cases after clipping and coiling; there were no cases of mortality or permanent morbidity. Immunostaining and histopathology verified loss of tunica media muscle coat and elastic lamina at the bleb site with smooth muscle actin and Type IV collagen positivity in 15 cases of aneurysm resection. Screening with 4D-CTA or 3D-CTA are noninvasive methods that can be employed in first degree relative of SAH patients and those with risk factors. Symptomatic aneurysrns need treatment, as a priority; direct surgery and coiling are recommended in unruptured aneurysms. Prediction of rupture point based on 4D-CTA is confirmed histologically.