Background and Purpose-We updated our previous review from 1996 on the risk of rupture of unruptured intracranial aneurysms, aiming to include the newly published articles. Methods-We reviewed all studies from our former meta-analysis and performed a Medline search for new studies published after 1996. We calculated overall risks of rupture for studies with a mean follow-up time of Ͻ5, 5 to 10, and Ͼ10 years. Relative risks (RR) were calculated by comparing the risk of rupture in patients with and without potential risk factors. We aimed to perform multivariable analyses of the different risk factors with meta-regression analysis. Results-We included 19 studies (10 new) with 4705 patients and 6556 unruptured aneurysms (follow-up 26 122 patient-years). The overall rupture risks were 1.2% (follow-up Ͻ5 years), 0.6% (follow-up 5 to 10 years), and 1.3% (follow-up Ͼ10 years). In the univariable analysis, statistically significant risk factors for rupture were age Ͼ60 years (RR 2.0; 95% confidence interval [CI], 1.1 to 3.7), female gender (RR 1.6; 95% CI, 1.1 to 2.4), Japanese or Finnish descent (RR 3.4; 95% CI, 2.6 to 4.4), size Ͼ5 mm (RR 2.3; 95% CI, 1.0 to 5.2), posterior circulation aneurysm (RR 2.5; 95% CI, 1.6 to 4.1), and symptomatic aneurysm (RR 4.4; 95% CI, 2.8 to 6.8). Meta-regression analysis yielded implausible results. Conclusions-Age, gender, population, size, site, and type of aneurysm should be considered in the decision whether to treat an unruptured aneurysm. Pooled multivariable analyses of individual data are needed to identify independent risk factors and to provide more reliable risk estimates for individual patients.

IntroductionWe related composition of cerebral thrombi to stroke subtype and attenuation on non-contrast CT (NCCT) to gain more insight in etiopathogenesis and to validate thrombus attenuation as a new imaging biomarker for acute stroke.MethodsWe histopathologically investigated 22 thrombi retrieved after mechanical thrombectomy in acute stroke patients. First, thrombi were classified as fresh, lytic or organized. Second, percentages of red blood cells (RBCs), platelets and fibrin and number of red, white (respectively RBCs or platelets outnumbering other components with ≥15%) or mixed thrombi were compared between large artery atherosclerosis (LAA), cardioembolism, dissection and unknown subtype. Third, correlation between attenuation and RBCs, platelets and fibrin was calculated using Pearson's correlation coefficients (r).ResultsThrombi were fresh in 73% (n = 16), lytic in 18% (n = 4) and organized in 9% (n = 2). The stroke cause was LAA in eight (36%), cardioembolism in six (27%), dissection in three (14%), and unknown in five (23%) patients. LAA thrombi showed the highest percentage RBCs (median 50 (range 35–90)), followed by dissection (35 (20–40), p = 0.05), cardioembolism (35 (5–45), p = 0.013) and unknown subtype (25 (2–40), p = 0.006). No differences in platelets (p = 0.16) and fibrin (p = 0.52) between subtypes were found. LAA thrombi were classified as red or mixed (both n = 4), cardioembolisms as mixed (n = 5) or white (n = 1) and dissection as mixed (n = 3). There was a moderate positive correlation between attenuation and RBCs (r = 0.401, p = 0.049), and weak negative correlations with platelets (r = −0.368, p = 0.09) and fibrin (r = −0.073, p = 0.75).ConclusionsThe majority of cerebral thrombi is fresh. There are no differences in age of thrombi between subtypes. LAA thrombi have highest percentages RBCs, cardioembolism and unknown subtype lowest. No relationship exists between subtype and platelets or fibrin percentages. We found a correlation between the RBC-component and thrombus attenuation, which improves validation of thrombus attenuation on NCCT as an imaging biomarker for stroke management.

Introduction Vasospasm after aneurysmal subarachnoid hemorrhage (SAH) is thought to cause ischemia. To evaluate the contribution of vasospasm to delayed cerebral ischemia (DCI), we investigated the effect of vasospasm on cerebral perfusion and the relationship of vasospasm with DCI. Methods We studied 37 consecutive SAH patients with CT angiography (CTA) and CT perfusion (CTP) on admission and within 14 days after admission or at time of clinical deterioration. CTP values (cerebral blood volume, cerebral blood flow (CBF) and mean transit time), degree of vasospasm on CTA, and occurrence of DCI were recorded. Vasospasm was categorized as follows: no spasm (0-25% decrease in vessel diameter), moderate spasm (25-50% decrease), and severe spasm (>50% decrease). The correspondence of the flow territory of the most spastic vessel with the least perfused region was evaluated, and differences in perfusion values and occurrence of DCI between degrees of vasospasm were calculated with 95% confidence intervals (95% CI). Results Fourteen patients had no vasospasm, 16 were moderate, and seven were severe. In 65% of patients with spasm, the flow territory of the most spastic vessel corresponded with the least perfused region. There was significant CBF (milliliters per 100 g per minute) difference (−21.3; 95% CI, −37↔−5.3) between flow territories of severe and no vasospasm. Four of seven patients with severe, six of 16 with moderate, and three of 14 patients with no vasospasm had DCI. Conclusion Vasospasm decreases cerebral perfusion, but corresponds with the least perfused region in only two thirds of our patients. Furthermore, almost half of patients with severe vasospasm do not have DCI. Thus, although severe vasospasm can decrease perfusion, it may not result in DCI.

IntroductionTriple-H therapy and its separate components (hypervolemia, hemodilution, and hypertension) aim to increase cerebral perfusion in subarachnoid haemorrhage (SAH) patients with delayed cerebral ischemia. We systematically reviewed the literature on the effect of triple-H components on cerebral perfusion in SAH patients.MethodsWe searched medical databases to identify all articles until October 2009 (except case reports) on treatment with triple-H components in SAH patients with evaluation of the treatment using cerebral blood flow (CBF in ml/100 g/min) measurement. We summarized study design, patient and intervention characteristics, and calculated differences in mean CBF before and after intervention.ResultsEleven studies (4 to 51 patients per study) were included (one randomized trial). Hemodilution did not change CBF. One of seven studies on hypervolemia showed statistically significant CBF increase compared to baseline; there was no comparable control group. Two of four studies applying hypertension and one of two applying triple-H showed significant CBF increase, none used a control group. The large heterogeneity in interventions and study populations prohibited meta-analyses.ConclusionsThere is no good evidence from controlled studies for a positive effect of triple-H or its separate components on CBF in SAH patients. In uncontrolled studies, hypertension seems to be more effective in increasing CBF than hemodilution or hypervolemia.

IMPORTANCEThe risk of procedural clinical complications and the case-fatality rate (CFR) from preventive treatment of unruptured intracranial aneurysms varies between studies and may depend on treatment modality and risk factors. OBJECTIVE To assess current procedural clinical 30-day complications and the CFR from endovascular treatment (EVT) and neurosurgical treatment (NST) of unruptured intracranial aneurysms and risk factors of clinical complications.