軽症くも膜下出血の治療成績―転帰不良を来す要因の分析

Deteriorating Factors on the Outcome in Patients with Fair Grade of Subarachnoid Hemorrhage (WFNS GradeⅠ and Ⅱ)

Ⅰ．は じ め に

　脳動脈瘤破裂によるくも膜下出血（SAH）の治療は開頭によるclipping術，Guglielmi detachable coil（GDC）塞栓術など多様化している^2,5)．症候性脳血管攣縮（vasospasm：VS）への対策を含め周術期管理も洗練され，治療成績はよくなってきた^{1,9,10,16,18,19)}．それでも重症例（WFNS grade　Ⅳ，Ⅴ）は半数以上が転帰不良であり，一方軽症例でもいまだ10～20%は転帰不良となっている^{4,6,7, 11,13,14,17)}．

　そこで今回われわれは，軽症SAHの転帰不良となった原因を検討することとした．その要因としてVSをはじめ，さまざまに影響し合う因子が想定されるためロジスティック回帰（logistic regression analysis：LRA）を用いた．

Background and purpose　Although,the overall treatment results in aneurysmal subarachnoid hemorrhage (SAH) has been improving in recent years,more than 10% of the patients with WFNS gradeⅠandⅡwe have sought to determine the clinical variables for predicting poor functional outcome and symptomatic vasospasm (VS) in patients with individual WFNS grades.

　Measurements　The eligible patient fulfilled the following conditions; (1) ruptured aneurysm located in the anterior part of the circle of Willis,(2) surgically clipped followed by craniotomy under microscope,(3) early surgery within 72 hours,(4) classified to WFNS gradeⅠorⅡ. The medical records were retrospectively reviewed in 119 patients (63 of gradeⅠand 56 of gradeⅡ). Sex,age,Fisher's CT group,intraventricular hemorrhage (IVH),site of aneurysm,VS,hydrocephalus,premature bleeding and complications of various kinds were selected as the dependent variables. The contributions of these factors to outcome (Glasgow Outcome Scale,GOS) as well as VS were analyzed using the logistic regression method.

　Main results　Outcome was better in WFNS gradeⅠ(p=0.039),and VS occurred less often and responded well to various interventional techniques and drug delivery. No significant variables contributed to the poor outcome or VS in WFNS grade Ⅰ. In WFNS gradeⅡ,logistic regression analysis showed that VS (OR 34.6,95%CI,30.8-38.9,p =0.012) and the complications (OR 52.4,95%CI,46.5-59.1,p=0.004) were significant predictors for a poor outcome. Fisher's group 3 was also the only significant factors in VS (OR 3.78,95%CI,3.35-4.28,p =0.039). The cause for the difference in outcome and VS were discussed in detail.

　Conclusion　The vasospasm and various kinds of complications were the predictive factors of poor clinical outcome,in patient of WFNS gardeⅡ. Therefore,careful management and meticulous/pertinent surgical maneuvers are mandatory to obtain better results in aneurysmal SAH,even in better WFNS grades.