Aneurysm diameter as a risk factor for pretreatment rebleeding: a meta-analysis

Aneurysmal Inflow Rate Coefficient Predicts Ultra-early Rebleeding in Ruptured Intracranial Aneurysms: Preliminary Report of a Computational Fluid Dynamics Study

Rebleeding from a ruptured intracranial aneurysm has poor outcomes. Although numerous factors are associated with rebleeding, studies on computational fluid dynamics (CFD) on hemodynamic parameters associated with early rebleeding are scarce. In particular, no report of rebleeding in ultra-early phase exists. We aimed to elucidate the specific hemodynamic parameters associated with ultra-early rebleeding using CFD. In this study, the rebleeding group included patients with aneurysmal subarachnoid hemorrhage (aSAH) that rebled within 6 h from the onset. The control group included patients without rebleeding, observed for >10 h following the initial rupture. Clinical images after initial rupture and before rebleeding were used to build 3D vessel models for hemodynamic analysis focusing on the following parameters: time-averaged wall shear stress (WSS), normalized WSS, low shear area, oscillatory shear index, relative residence time, pressure loss coefficient, and aneurysmal inflow rate coefficient (AIRC). Five and 15 patients in the rebleeding and control groups, respectively, met the inclusion criteria. The World Federation of Neurosurgical Surgeons grade was significantly higher in the rebleeding group (p = 0.0088). Hemodynamic analysis showed significantly higher AIRC in the rebleeding group (p = 0.042). The other parameters were not significantly different between groups. There were no significant differences or correlations between SAH severity and AIRC. AIRC was identified as a hemodynamic parameter associated with ultra-early rebleeding of ruptured intracranial aneurysms. Thus, AIRC calculation may enable the prediction of ultra-early rebleeding.

Impact of immediate general anesthesia in the emergency room on prevention of rebleeding after subarachnoid hemorrhage

BACKGROUND

Aneurysm rebleeding is fatal in patients with aneurysmal subarachnoid hemorrhage (aSAH). We aimed to investigate whether immediate general anesthesia (iGA) management in the emergency room, upon arrival, prevents rebleeding after admission and reduces mortality following aSAH.

METHODS

The clinical data of 3033 patients with World Federation of Neurosurgical Societies (WFNS) grade 1, 2, or 3 aSAH from the Nagasaki SAH Registry Study between 2001 and 2018 were retrospectively analyzed. iGA was defined as sedation and analgesia using intravenous anesthetics and opioids combined with intubation induction. We calculated crude and adjusted odds ratios to evaluate the associations between iGA and the risk of rebleeding/death using multivariable logistic regression models with fully conditional specification for multiple imputations. In the analysis of the relationship between iGA and death, we excluded patients with aSAH who died within 3 days after the onset of symptoms.

RESULTS

Of the 3033 patients with aSAH who met the eligibility criteria, 175 patients (5.8%) received iGA (mean age, 62.4 years; 49 were male). Heart disease, WFNS grade, and lack of iGA were independently associated with rebleeding in the multivariable analysis with multiple imputations. Among the 3033 patients, 15 were excluded due to death within 3 days after the onset of symptoms. After excluding these cases, our analysis revealed that age, diabetes mellitus, history of cerebrovascular disease, WFNS grade, Fisher grade, lack of iGA, rebleeding, postoperative rebleeding, no shunt operation, and symptomatic spasm were independently associated with mortality.

CONCLUSIONS

Management by iGA was associated with a 0.28-fold decrease in the risks of both rebleeding and mortality in patients with aSAH, even after adjusting for the patient's history of diseases, comorbidities, and aSAH status. Thus, iGA can be a treatment for the prevention of rebleeding before aneurysmal obliteration treatment.

LVIS-within-enterprise double-stent technique with coil embolization in the treatment of patients with acutely ruptured intracranial vertebrobasilar artery-dissecting aneurysms

Objective

This study aimed to evaluate the feasibility of the low-profile visualized intraluminal support (LVIS)-within-enterprise double-stent technique for patients with acutely ruptured intracranial vertebrobasilar artery-dissecting aneurysms (ari-VBDAs).

Methods

A total of 30 patients with ari-VBDAs who underwent reconstructive treatment using LVIS-within-enterprise double-stent technique with coil embolization between January 2014 and May 2022 were retrospectively enrolled. Patients' characteristics and clinical and imaging outcomes were reviewed. The functional outcomes were assessed using the modified Rankin scale (mRS).

Results

A total of 34 ari-VBDAs were identified, including seven (20.6%) basilar artery aneurysms and 27 (79.4%) vertebral artery aneurysms. All aneurysms were successfully treated in the acute phase. In total, six (20.0%) patients experienced in-hospital serious adverse events, including two deaths (6.7%). The median clinical follow-up time of the remaining 28 patients was 20.0 (IQR, 7.3-40.8) months. The incidences of dependency or death (mRS score of 3-6) at discharge and at the last follow-up were 16.7% and 14.3%, respectively. Aneurysm rebleeding occurred in one (3.3%) patient periprocedurally. In total, three (10.0%) patients had ischemic events, one of which occurred during the periprocedural period and two occurred during follow-up. A total of two patients (6.7%) underwent ventriculoperitoneal shunt. Imaging follow-up was available for 14 patients at the median of 12.0 (IQR, 7.0-12.3) months, with a complete occlusion rate of 93.3% (14/15). In total, one patient experienced parent artery occlusion, and no aneurysm was recanalized.

Conclusion

LVIS-within-enterprise double-stent technique with coil embolization for the treatment of patients with ari-VBDAs could be performed with a good safety profile and high technical success rate. The rate of complete aneurysm occlusion during follow-up seemed to be satisfactory.

Development and Internal Validation of the ARISE Prediction Models for Rebleeding After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal rerupture is one of the most important determents for outcome after aneurysmal subarachnoid hemorrhage and still occurs frequently because individual risk assessment is challenging given the heterogeneity in patient characteristics and aneurysm morphology.

OBJECTIVE

To develop and internally validate a practical prediction model to estimate the risk of aneurysmal rerupture before aneurysm closure.

METHODS

We designed a multinational cohort study of 2 prospective hospital registries and 3 retrospective observational studies to predict the risk of computed tomography confirmed rebleeding within 24 and 72 hours after ictus. We assessed predictors with Cox proportional hazard regression analysis.

RESULTS

Rerupture occurred in 269 of 2075 patients. The cumulative incidence equaled 7% and 11% at 24 and 72 hours, respectively. Our base model included hypertension, World Federation of Neurosurgical Societies scale, Fisher grade, aneurysm size, and cerebrospinal fluid drainage before aneurysm closure and showed good discrimination with an optimism corrected c-statistic of 0.77. When we extend the base model with aneurysm irregularity, the optimism-corrected c-statistic increased to 0.79.

CONCLUSION

Our prediction models reliably estimate the risk of aneurysm rerupture after aneurysmal subarachnoid hemorrhage using predictor variables available upon hospital admission. An online prognostic calculator is accessible at https://www.evidencio.com/models/show/2626 .

Association of Rebleeding and Delayed Cerebral Ischemia with Long-term Mortality Among 1-year Survivors After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND OBJECTIVE

The potential impact of rebleeding and Delayed Cerebral Ischemia (DCI) on long-term survival in patients with aneurysmal subarachnoid hemorrhage (aSAH) remained unclear. This study aimed to investigate whether DCI and rebleeding increase the risk of long-term all-cause mortality in patients with aSAH who survived the follow-up period of one year.

METHODS

We retrospectively collected data on patients with atraumatic aSAH who were still alive 12 months after aSAH occurrence between December 2013 and June 2019 from the electronic health system. Patients were then classified by the occurrence of rebleeding or DCI during hospitalization. Death records were obtained from an administrative database, the Chinese Household Registration Administration System, until April 20, 2021. Multivariable Cox proportional hazards models were used to compare overall survival in different groups. Sensitivity analysis was performed with propensity-score matching (PSM).

RESULTS

A total of 2,607 patients were alive one year after aSAH. The crude annual death rate from any cause among patients who had rebleeding (7.2 per 100 person-years) and patients who had DCI (3.7 per 100 person-years) during hospitalization was higher than that of patients with neither event (2.1 per 100 person-years). Multivariate analysis showed that rebleeding is an independent risk factor for long-term mortality (adjusted hazard ratio (aHR), 2.37; 95% confidence interval (CI), 1.47- 3.81). DCI was an independent prognostic factor of poorer overall survival (aHR, 2.09; 95% CI, 1.54-2.84).

CONCLUSION

Amongst patients alive one year after aSAH, rebleeding and DCI during hospitalization were independently associated with higher rates of long-term mortality.

Silk Vista Baby flow diverter stent for ruptured intracranial aneurysms: a retrospective observational study

PURPOSE

Flow diversion changed the approach to complex intracranial aneurysms, leading to a widespread use and a rapid technological evolution. Indeed, indications continued to expand, including ruptured intracranial aneurysms in selected cases. Recently, new devices have been designed specifically to target smaller vessels. Therefore, we conducted a multicenter study to evaluate clinical outcome, complications, and occlusion rate of patients with ruptured aneurysms treated with new generation low profile Silk Vista Baby (SVB) flow diverter stent (FD).

METHODS

We performed a retrospective observational study on consecutive patients who underwent treatment with SVB for ruptured aneurysms at 12 Italian centers. Primary end point was favorable clinical outcome rate, defined as modified ranking score (mRS) of 0-2 at the 3 months. Secondary outcomes were complication rate, aneurysm re-rupture, and complete aneurysm occlusion at last radiological follow-up.

RESULTS

Twenty-five patients were included; at 3 months' follow-up, 19 patients (79.1%) had favorable clinical outcome (mRS 0-2). Three patients (12.5%) died during follow-up. In-stent thrombosis occurred in two cases (8.3%), managed with glycoprotein IIb/IIIA and intra-stent angioplasty, without clinical consequences. In 18 (85.7%) patients, complete occlusion at 3 months was demonstrated. No rebleeding occurred during follow-up. Presentation with unfavorable World Federation of Neurosurgical Societies grading system (WFNS) and posterior circulation location were both significantly correlated with unfavorable clinical outcome (p = 0.005 and p = 0.02).

CONCLUSIONS

Our data suggests that low profile FD treatment of ruptured intracranial aneurysms located distally of the circle of Willis is feasible. New generation low profile FD may represent an alternative option in carefully selected cases.

Different Hemodynamic Characteristics and Resulting in Different Risks of Rupture Between Wide-Neck and Narrow-Neck Aneurysms

Objective

This study aimed to determine the ruptured rate and hemodynamic difference between wide-neck aneurysms (WNAs) and narrow-neck aneurysms (NNAs), as well as the hemodynamic parameters of risk factors for aneurysm rupture.

Methods

A total of 121 cases of intracranial aneurysms (IAs) were studied retrospectively between January 2019 and April 2021 at Renmin Hospital of Wuhan University. Intracranial aneurysms were classified into four types: ruptured wide-neck aneurysms (RWNAs), unruptured wide-neck aneurysms (UWNAs), ruptured narrow-neck aneurysms (RNNAs), and unruptured narrow-neck aneurysms (UNNAs). The Chi-square test was used to compare differences in rupture ratios. The clinical characteristics and hemodynamics were analyzed statistically to reveal the rupture risk factors. Moreover, significant parameters were subjected to binary logistic regression analysis to identify the independent predictive factors. The receiver operating characteristic (ROC) curve was performed to obtain cutoff values.

Results

WNAs ruptured more frequently than NNAs (P = 0.033). Ruptured intracranial aneurysms (RIAs) were characterized by significantly higher intra-aneurysmal pressure (IAP), wall shear stress (WSS), wall shear stress gradient (WSSG), and lower normalized wall shear stress (NWSS) than unruptured intracranial aneurysms (UIAs). RWNAs had higher IAP, WSS, and lower NWSS than UWNAs (P < 0.05). RNNAs had higher IAP, Streamwise WSSG and lower NWSS compared to UNNAs (P < 0.05). Binary logistic regression revealed that IAP and WSS were independent predictive risk factors for WNAs rupture, with cut-off values of 405.5 and 6.66 Pa, respectively. Also, IAP was an independent predictive risk factor for NNA rupture, with a cut-off value of 255.3 Pa.

Conclusions

Wide-neck aneurysms and narrow-neck aneurysms have diverse hemodynamics, which prompts a higher rupture ratio for WNAs. IAP could characterize the rupture risk in both WNAs and NNAs independently, but WSS could only predict the rupture risk in WNAs. This research might assist neurosurgeons with fostering a more sensible strategy for the treatment of IAs.

Rs12976445 polymorphism is associated with the risk of post-SAH re-bleeding by modulating the expression of microRNA-125 and ET-1

This study aimed to study the association between rs12976445 polymorphism and the incidence of IA re-bleeding. Genotype and allele frequency analysis was performed to study the association between rs12976445 polymorphism and the risk of IA re-bleeding. Western blot, ELISA and real-time RT-PCR were conducted to measure the relative expression of miR-125a, ET1 mRNA and ET1 protein. Computational analysis and luciferase assays were utilized to investigate the association between the expression of miR-125a and ET1 mRNA. No significant differences were observed between IA patients with or without symptoms of re-bleeding. Subsequent analyses indicated that the T allele was significantly associated with the reduced risk of IA re-bleeding. In patients carrying the CC genotype, miR-125a level was up-regulated while ET1 mRNA/protein levels were reduced compared with those in patients carrying the CT or TT genotype. And ET1 mRNA was identified as a virtual target gene of miR-125a with a potential miR-125a binding site located on its 3’UTR. Accordingly, the ET mRNA/protein levels could be suppressed by the transfection of miR-125a precursors, but the transfection of ET1 siRNA exhibited no effect on the expression of miR-125a. Therefore, an increased level of miR-125a can lead to the increased risk of IA re-bleeding. Since miR-125a level is higher in CC-genotyped patients, it can be concluded that the presence of T allele in the rs12976445 polymorphism is associated with a lower risk of IA re-bleeding, and miR-125a may be used as a novel diagnostic and therapeutic target for IA rupture.

Elevated Glucose-Potassium Ratio Predicts Preoperative Rebleeding in Patients With Aneurysmal Subarachnoid Hemorrhage

Introduction: Recent reports revealed that higher serum glucose-potassium ratio (GPR) levels at admission were significantly associated with poor outcomes at 3 months following aneurysmal subarachnoid hemorrhage (aSAH). This study aimed to investigate the association between GPR and the risk of rebleeding following aSAH. Methods: This single-center retrospective study of patients with aSAH was conducted in our hospital between January 2008 and December 2020. Patients meeting the inclusion criteria were divided into the rebleed group and the non-rebleed group. Univariate and multivariate analyses were implemented to assess the association between risk factors of rebleeding and outcomes. Results: A total of 1,367 patients experiencing aSAH, 744 patients who met the entry criteria in the study [mean age (54.89 ± 11.30) years; 60.50% female patients], of whom 45 (6.05%) developed rebleeding. The patients in the rebleed group had significantly higher GPR levels than those of patients without rebleeding [2.13 (1.56-3.20) vs. 1.49 (1.23-1.87); p < 0.001]. Multivariable analysis revealed that higher mFisher grade and GPR were associated with rebleeding [mFisher grade, odds ratios (OR) 0.361, 95% CI 0.166-0.783, p = 0.01; GPR, OR 0.254, 95% CI 0.13-0.495, p < 0.001]. The receiver operating characteristics (ROCs) analysis described that the suitable cut-off value for GPR as a predictor for rebleeding in patients with aSAH was determined as 2.09 (the area under the curve [AUC] was 0.729, 95% CI 0.696-0.761, p < 0.0001; the sensitivity was 53.33%, and the specificity was 83.98%). Pearson correlation analysis showed a significant positive correlation between GPR and mFisher grade, between GPR and Hunt-Hess grade (mFisher grade r = 0.4271, OR 0.1824, 95% CI 0.3665-0.4842, p < 0.001; Hunt-Hess grade r = 0.4248, OR 0.1836, 95% CI 0.3697-0.4854, p < 0.001). The patients in the poor outcome had significantly higher GPR levels than those of patients in the good outcome [1.87 (1.53-2.42) vs. 1.45 (1.20-1.80); p < 0.001]. Multivariable analysis demonstrated that GPR was an independent predictor for poor prognosis. The AUC of GPR was 0.709 (95% CI 0.675-0.741; p < 0.0001) (sensitivity = 77.70%; specificity = 55.54%) for poor prognosis. Conclusion: Higher preoperative serum GPR level was associated with Hunt-Hess grade, mFisher grade, rebleeding, and unfunctional outcome, and that they predicted preoperative rebleeding and the 90-days outcome of non-diabetic patients with aSAH, who had potentially relevant clinical implications in patients with aSAH.

Rebleeding of Ruptured Intracranial Aneurysm After Admission: A Multidimensional Nomogram Model to Risk Assessment

Objective

Rebleeding is recognized as the main cause of mortality after intracranial aneurysm rupture. Though timely intervention can prevent poor prognosis, there is no agreement on the surgical priority and choosing medical treatment for a short period after rupture. The aim of this study was to investigate the risk factors related to the rebleeding after admission and establish predicting models for better clinical decision-making.

Methods

The patients with ruptured intracranial aneurysms (RIAs) between January 2018 and September 2020 were reviewed. All patients fell to the primary and the validation cohort by January 2020. The hemodynamic parameters were determined through the computational fluid dynamics simulation. Cox regression analysis was conducted to identify the risk factors of rebleeding. Based on the independent risk factors, nomogram models were built, and their predicting accuracy was assessed by using the area under the curves (AUCs).

Result

A total of 577 patients with RIAs were enrolled in this present study, 86 patients of them were identified as undergoing rebleeding after admission. Thirteen parameters were identified as significantly different between stable and rebleeding aneurysms in the primary cohort. Cox regression analysis demonstrated that six parameters, including hypertension [hazard ratio (HR), 2.54; P = 0.044], bifurcation site (HR, 1.95; P = 0.013), irregular shape (HR, 4.22; P = 0.002), aspect ratio (HR, 12.91; P < 0.001), normalized wall shear stress average (HR, 0.16; P = 0.002), and oscillatory stress index (HR, 1.14; P < 0.001) were independent risk factors related to the rebleeding after admission. Two nomograms were established, the nomogram including clinical, morphological, and hemodynamic features (CMH nomogram) had the highest predicting accuracy (AUC, 0.92), followed by the nomogram including clinical and morphological features (CM nomogram; AUC, 0.83), ELAPSS score (AUC, 0.61), and PHASES score (AUC, 0.54). The calibration curve for the probability of rebleeding showed good agreement between prediction by nomograms and actual observation. In the validation cohort, the discrimination of the CMH nomogram was superior to the other models (AUC, 0.93 vs. 0.86, 0.71 and 0.48).

Conclusion

We presented two nomogram models, named CMH nomogram and CM nomogram, which could assist in identifying the RIAs with high risk of rebleeding.

Risk Factors for Higher Volume of Hemorrhage in Ruptured Anterior Circulation Intracranial Aneurysms

Purpose: To explore the influencing factors of volume hemorrhage in ruptured anterior circulation aneurysms, so as to identify the characteristics of anterior circulation aneurysms with high volume of hemorrhage, and to provide advice for clinical diagnosis and treatment for those aneurysms. Methods: We retrospectively reviewed 437 cases of ruptured anterior intracranial aneurysms in our center between the years 2012 and 2017. According to the inclusion criteria, a total of 100 qualified patients were screened out. We collected demographic characteristics, environmental exposure, and admission status of enrolled patients. In addition, morphological parameters and location of aneurysms were also included. The semiautomatic threshold method was used to measure the volume of hemorrhage. According to the results, the patients were divided into the group with high blood volume and low blood volume. Univariate and multivariate logistic regression analyses were used to discover the related factors affecting the bleeding volume. Results: In univariable analysis, pulse pressure (P = 0.014) showed a significant difference at the P < 0.05 test level. In terms of aneurysm morphology, the irregular shape (P < 0.001), calcification (P = 0.001), and flow angle (P = 0.006) showed significant statistical differences between the two groups at the P < 0.01 level (P < 0.01). Multivariate logistic regression analysis showed that irregular shape (OR = 5.370 P = 0.002 < 0.05), large flow angle (OR = 1.033 P = 0.016 < 0.05), and calcification (OR = 5.460 P = 0.003 < 0.05) were risk factors for volume of hemorrhage in ruptured anterior circulation aneurysms. The influence of hypertension history was at critical state (OR = 2.877 P = 0.051 > 005). Conclusions: According to our analysis results, intracranial anterior circulation aneurysms with irregular shapes, calcifications, and large flow angle are more dangerous. Aneurysms with these characteristics often have a large amount of hemorrhage, requiring timely treatment in clinical practice.

Should Cerebral Angiography Be Avoided within Three Hours after Subarachnoid Hemorrhage?

Objective

While the risk of aneurysmal rebleeding induced by catheter cerebral angiography is a serious concern and can delay angiography for a few hours after a subarachnoid hemorrhage (SAH), current angiographic technology and techniques have been much improved. Therefore, this study investigated the risk of aneurysmal rebleeding when using a recent angiographic technique immediately after SAH.

Methods

Patients with acute SAH underwent immediate catheter angiography on admission. A four-vessel examination was conducted using a biplane digital subtraction angiography (DSA) system that applied a low injection rate and small volume of a diluted contrast, along with appropriate control of hypertension. Intra-angiographic aneurysmal rebleeding was diagnosed in cases of extravasation of the contrast medium during angiography or increased intracranial bleeding evident in flat-panel detector computed tomography scans.

Results

In-hospital recurrent hemorrhages before definitive treatment to obliterate the ruptured aneurysm occurred in 11 of 266 patients (4.1%). Following a univariate analysis, a multivariate analysis using a logistic regression analysis revealed that modified Fisher grade 4 was a statistically significant risk factor for an in-hospital recurrent hemorrhage (p =0.032). Cerebral angiography after SAH was performed on 88 patients ≤3 hours, 74 patients between 3–6 hours, and 104 patients >6 hours. None of the time intervals showed any cases of intra-angiographic rebleeding. Moreover, even though the DSA ≤3 hours group included more patients with a poor clinical grade and modified Fisher grade 4, no case of aneurysmal rebleeding occurred during erebral angiography.

Conclusion

Despite the high risk of aneurysmal rebleeding within a few hours after SAH, emergency cerebral angiography after SAH can be acceptable without increasing the risk of intra-angiographic rebleeding when using current angiographic techniques and equipment.

Flow diversion treatment for acutely ruptured aneurysms

Background and purpose

Flow diverters are sometimes used in the setting of acutely ruptured aneurysms. However, thromboembolic and hemorrhagic complications are feared and evidence regarding safety is limited. Therefore, in this multicenter study we evaluated complications, clinical, and angiographic outcomes of patients treated with a flow diverter for acutely ruptured aneurysms.

Methods

We conducted a retrospective observational study of 44 consecutive patients who underwent flow diverter treatment within 15 days after rupture of an intracranial aneurysm at six centers. The primary end point was good clinical outcome, defined as modified Rankin Scale score (mRS) 0–2. Secondary endpoints were procedure-related complications and complete aneurysm occlusion at follow-up.

Results

At follow-up (median 3.4 months) 20 patients (45%) had a good clinical outcome. In 20 patients (45%), 25 procedure-related complications occurred. These resulted in permanent neurologic deficits in 12 patients (27%). In 5 patients (11%) aneurysm re-rupture occurred. Eight patients died resulting in an all-cause mortality rate of 18%. Procedure-related complications were associated with a poor clinical outcome (mRS 3–6; OR 5.1(95% CI 1.0 to 24.9), p=0.04). Large aneurysms were prone to re-rupture with rebleed rates of 60% (3/5) vs 5% (2/39) (p=0.01) for aneurysms with a size ≥20 mm and <20 mm, respectively. Follow-up angiography in 29 patients (median 9.7 months) showed complete aneurysm occlusion in 27 (93%).

Conclusion

Flow diverter treatment of ruptured intracranial aneurysms was associated with high rates of procedure-related complications including aneurysm re-ruptures. Complications were associated with poor clinical outcome. In patients with available angiographic follow-up, a high occlusion rate was observed.

Small ruptured intracranial aneurysms: the risk of massive bleeding and rebleeding

OBJECTIVE

The risk of hemorrhagic events in small ruptured aneurysms remains unclear. Due to less arterial wall, small ruptured aneurysms may be correlated with massive bleeding and rebleeding. Therefore, it may contribute to treatment to evaluate the amount of bleeding and the risk of rebleeding in small ruptured aneurysms.

METHODS

A retrospective cohort study of all consecutive patients with intracranial aneurysms admitted to our hospital from February 2013 to December 2017 was carried out. Ruptured aneurysms were divided into small ruptured aneurysm (0-5 mm) group and large ruptured aneurysm (5 mm) group for analysis. The difference of bleeding volume, rebleeding and clinical outcome were analyzed between the two groups.

RESULTS

A total of 738 patients with aneurysmal subarachnoid hemorrhage (SAH) were included in this study and small ruptured aneurysms accounted for 49.2% of all ruptured aneurysms. Univariate analysis showed that the amount of bleeding (14.5 ± 7.1 vs. 14.4 ± 7.3; P = 0.867), rebleeding (8.3% vs. 10.9%; P = 0.261) and poor outcome (29.6% vs. 23.1%; P = 0.055) were similar between the two groups. Multivariable analysis showed that hypertension was obviously associated with the amount of bleeding (adjusted odds ratio (aOR), 3.25 [1.81-4.69]; P < 0.001) and rebleeding (aOR, 3.31 [1.10-9.99]; P = 0.034) in small ruptured aneurysms, and its effect on rebleeding of small ruptured aneurysms is greater than that of large ruptured aneurysms.

CONCLUSIONS

The risk of hemorrhagic events in small ruptured aneurysms is similar to that in large ruptured aneurysms, especially those patients with small ruptured aneurysms that complicated with hypertension are at an increased risk of massive SAH and rebleeding.

Thromboelastography with Platelet Mapping Detects Platelet Dysfunction in Patients with Aneurysmal Subarachnoid Hemorrhage with Rebleeding

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) has high rates of disability and mortality, and aneurysm rebleeding is associated with poor functional outcomes. Thrombelastography with platelet mapping (TEG-PM) measures platelet function; however, it has not yet been researched in aSAH. We aimed to use TEG-PM to detect changes in platelet function in patients with aSAH and the difference in patients with and without rebleeding.

METHODS

We retrospectively included patients with aSAH who underwent a TEG-PM test on admission. Rebleeding was diagnosed according to clinical and imaging data. TEG-PM data of patients with unruptured intracranial aneurysms (UIA) were also obtained as controls. Univariate and multivariate logistic regression models were performed to investigate the relationship between the platelet function and rebleeding.

RESULTS

A total of 245 aSAH patients and 32 UIA patients were included in our study. Compared with controls, patients with aSAH demonstrated higher arachidonic acid (AA) and adenosine diphosphate (ADP) inhibition of platelet function (P<0.05). Among them, 27 patients with Hunt-Hess grade IV or V were classified as the severe SAH group. There was a significant correlation between the severe SAH group and the degree of pathway inhibition (P<0.05). Furthermore, AA (Spearman's r=0.264, P<0.001) and ADP (Spearman's r=0.183, P=0.004) inhibition were elevated in Hunt-Hess grade-dependent manners. The AA (Spearman's r=0.169, P=0.008) and ADP (Spearman's r=0.233, P<0.001) inhibition were also significantly correlated with Fisher grade. Thirty-five patients (14.3%) suffered rebleeding. Rebleeding was significantly correlated with systolic blood pressure (P=0.011), diastolic blood pressure (P=0.008), Hunt-Hess grade (P=0.034), Fisher grade (P=0.015), AA inhibition (P<0.001), and ADP inhibition (P<0.001). Multivariate logistic regression analysis model revealed that both AA (P=0.037) and ADP inhibition (P=0.008) were independent determinants for rebleeding.

CONCLUSION

TEG-PM may assess platelet dysfunction in patients with aSAH, and the diminished platelet response to ADP and AA may be associated with rebleeding. These findings deserve further investigation.

Aneurysm rebleeding before therapy: a predictable disaster?

OBJECTIVE

Current guidelines for subarachnoid hemorrhage (SAH) include early aneurysm treatment within 72 hours after ictus. However, aneurysm rebleeding remains a crucial complication of SAH. The aim of this study was to identify independent predictors allowing early stratification of SAH patients for rebleeding risk.

METHODS

All patients admitted to the authors' institution with ruptured aneurysms during a 14-year period were eligible for this retrospective study. Demographic and radiographic parameters, aneurysm characteristics, medical history, and medications as well as baseline parameters at admission (blood pressure and laboratory parameters) were evaluated in univariate and multivariate analyses. A novel risk score was created using independent risk factors.

RESULTS

Data from 984 cases could be included into the final analysis. Aneurysm rebleeding occurred in 58 cases (5.9%), and in 48 of these cases (82.8%) rerupture occurred within 24 hours after SAH. Of over 30 tested associations, preexisting arterial hypertension (p = 0.02; adjusted odds ratio [aOR] 2.56, 1 score point), aneurysm location at the basilar artery (p = 0.001, aOR 4.5, 2 score points), sac size ≥ 9 mm (p = 0.04, aOR 1.9, 1 score point), presence of intracerebral hemorrhage (p = 0.001, aOR 4.29, 2 score points), and acute hydrocephalus (p < 0.001, aOR 6.27, 3 score points) independently predicted aneurysm rebleeding. A score built upon these parameters (0-9 points) showed a good diagnostic accuracy (p < 0.001, area under the curve 0.780) for rebleeding prediction.

CONCLUSIONS

Certain patient-, aneurysm-, and SAH-specific parameters can reliably predict aneurysm rerupture. A score developed according to these parameters might help to identify individuals that would profit from immediate aneurysm occlusion.

Aneurysm characteristics and risk of rebleeding after subarachnoid haemorrhage

Introduction

Knowledge of risk factors for rebleeding after aneurysmal subarachnoid haemorrhage can help tailoring ultra-early aneurysm treatment. Previous studies have identified aneurysm size and various patient-related risk factors for early (≤24 h) rebleeding, but it remains unknown if aneurysm configuration is also a risk factor. We investigated whether irregular shape, aspect- and bottleneck ratio of the aneurysm are independent risk factors for early rebleeding after aneurysmal subarachnoid haemorrhage.

Patients and methods

From a prospectively collected institutional database, we investigated data from consecutive aneurysmal subarachnoid haemorrhage patients who were admitted ≤24 h after onset between December 2009 and January 2015. The admission computed tomographic angiogram was used to assess aneurysm size and configuration. With Cox regression, we calculated stepwise-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for irregular shape, aspect ratio ≥1.6 mm and bottleneck ratio ≥1.6 mm.

Results

Of 409 included patients, 34 (8%) patients had in-hospital rebleeding ≤24 h after ictus. Irregular shape was an independent risk factor for rebleeding (HR: 3.9, 95% CI: 1.3–11.3) after adjustment for age, sex, PAASH score, aneurysm location, aneurysm size and aspect- and bottleneck ratio. Aspect ratio ≥1.6 mm (HR: 2.3, 95% CI: 0.8–6.5) and bottleneck ratio ≥1.6 mm (HR: 1.7, 95% CI: 0.8–3.6) were associated with an increased risk of rebleeding, but were not independent risk factors after multivariable adjustment.

Conclusions

Irregular shape is an independent risk factor for early rebleeding. However, since the majority of subarachnoid haemorrhage patients have an irregular aneurysm, additional risk factors have to be found for aneurysm treatment prioritisation.

Volume of cerebrospinal fluid drainage as a predictor for pretreatment aneurysmal rebleeding

OBJECTIVE

Initiation of external CSF drainage has been associated with a significant increase in rebleeding probability after aneurysmal subarachnoid hemorrhage (aSAH). However, the implications for acute management are uncertain. The purpose of this study was to evaluate the role of the amount of drained CSF on aneurysmal rebleeding.

METHODS

Consecutive patients with aSAH were analyzed retrospectively. Radiologically confirmed cases of aneurysmal in-hospital rebleeding were identified and predictor variables for rebleeding were retrieved from hospital records. Clinical predictors were identified through multivariate analysis, and logistic regression analysis was performed to ascertain the cutoff value for the rebleeding probability.

RESULTS

The study included 194 patients. Eighteen cases (9.3%) of in-hospital rebleeding could be identified. Using multivariate analysis, in-hospital rebleeding was significantly associated with initiation of CSF drainage (p = 0.001) and CSF drainage volume (63 ml [interquartile range (IQR) 55–69 ml] vs 25 ml [IQR 10–35 ml], p < 0.001). Logistic regression showed that 58 ml of CSF drainage within 6 hours results in a 50% rebleeding probability. The relative risk (RR) for rebleeding after drainage of more than 60 ml in 6 hours was 5.4 times greater compared with patients with less CSF drainage (RR 5.403, 95% CI 2.481–11.767; p < 0.001, number needed to harm = 1.687).

CONCLUSIONS

Volume of CSF drainage was highly correlated with the probability of in-hospital aneurysmal rebleeding. These findings suggest that the rebleeding probability can be affected in acute management should the placement of an external ventricular catheter be necessary. This finding necessitates meticulous control of the amount of drained CSF and the development of a definitive treatment protocol for this group of patients.

Acute rerupture after coil embolization of ruptured intracranial saccular aneurysms: A literature review

Acute rerupture after coil embolization is defined as rerupture within three days after treatment; its prognosis is worse than that of rebleeding at other time periods. However, to date, little is known about complications during the acute phase. Therefore, we used the PubMed database to perform a review of acute rerupture after coil embolization of ruptured intracranial saccular aneurysms and increase our understanding. After reviewing the complications, we found that the cause of acute rerupture is unclear, but the following risk factors are involved: incomplete occlusion of the initial aneurysm, the presence of a hematoma adjacent to a ruptured aneurysm, an aneurysmal outpouching, poor Hunt-Hess grade at the time of treatment, and the location of the aneurysm in an anterior communicating artery. In addition, intraoperative rupture is a non-negligible cause. Acute rerupture after coil embolization mainly occurs within the first 24 hours after the procedure. Brain computed tomography is the gold standard for diagnosing acute rebleeding of a coiled aneurysm. For acute rerupture after coil embolization, prevention is critical, and complete occlusion of the aneurysm in the first session is the best protection against acute rebleeding. In addition, a restricted postembolization anticoagulation strategy is recommended for patients with high-risk aneurysms. For patients with an adjacent hematoma, surgical clipping is recommended. Most patients present no changes immediately after acute rebleeding because of their poor condition. However, surgical or endovascular treatments can be attempted if the patient is in an acceptable condition. Even so, the outcomes are typically unsatisfactory.

Endothelin polymorphisms as a risk factor for cerebral aneurysm rebleeding following aneurysmal subarachnoid hemorrhage

BACKGROUND

Aneurysm rebleeding following presentation with aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and poor functional outcome. While a substantial genetic contribution to aneurysm formation and rupture is known, the genetic influence on the risk of rebleeding is poorly understood.

OBJECTIVE

To evaluate the role of common endothelin polymorphisms in aneurysm rebleeding.

PATIENTS AND METHODS

Blood sample from all patients enrolled in the CARAS (Cerebral Aneurysm Renin Angiotensin System) study were used for genetic evaluation. The CARAS study prospectively enrolled aSAH patients at two academic institutions in the United States from 2012 to 2015. Common endothelin SNPs were detected using 5'exonnuclease (Taqman) genotyping assays. Analysis of associations between endothelin single nucleotide polymorphisms (SNP) and aneurysm rebleeding was performed.

RESULTS

One hundred and forty-nine aSAH patients were included. Acute spontaneous aneurysm rebleeding occurred in 5 (3.4%) patients. Multivariable analysis identified the TT genotype for EDN1 G/T SNP (rs2070699; OR 97.4, 95% CI 3.825-2479.984, p=0.006) as an independent risk factor for aneurysm rebleeding. Aneurysm rebleeding was associated with an unfavorable functional outcome (mRS 3-6) at last follow up in all 5 patients.

CONCLUSION

Aneurysm rebleeding following presentation with aSAH was independently associated with the TT genotype of the EDN1 G/T SNP. All patients with acute spontaneous aneurysm rebleeding suffered a poor functional outcome at last follow up.

Aneurysm rebleeding after placement of external ventricular drainage: a systematic review and meta-analysis

BACKGROUND

The association between external ventricular drainage (EVD) and aneurysm rerupture is still a controversial issue. We performed a systematic review and meta-analysis of published series reporting data of EVD placement in aneurysmal subarachnoid hemorrhage (SAH) with the aim to evaluate the relationship between ventricular drainage and aneurysm rebleeding.

METHOD

PRISMA/MOOSE guidelines were followed. The Newcastle-Ottawa Scale was used to assess the quality of the studies. We conducted a comprehensive literature search of three databases (PubMed, Ovid MEDLINE, and Ovid EMBASE) on series reporting patients with EVD placement and aneurysmal SAH. The reported studies were analyzed with a primary aim to calculate the strength of the association (odds ratio) between rebleeding and EVD placement in patients with SAH.

RESULTS

Our systematic review included 16 articles with a total of 6804 patients with SAH of which 595 (8.7%) had aneurysmal rebleeding. Ventricular drainage was inserted in 19% of patients. Rebleeding occurred in 18.8% (95% CI = 16.4-20.6%) of patients requiring EVD and in 6.4% (95% CI = 5.8-7.1%) of patients who did not require EVD (OR = 3.92, p < 0.0001). The mean time between EVD placement and rebleeding was 1 h (range, 0-8 h). The maximal aneurysm diameter of patients with rerupture was larger when compared with patients without rerupture (9.9 mm vs. 7.5 mm; p < 0.04). High Fisher grades (III-IV) were present in 75% of patients with rerupture and in 60% of patients without aneurysmal rerupture (p < 0.0001).

CONCLUSIONS

Our study conclusively defined an association between EVD and rebleeding. However, the effective role of EVD in aneurysm rebleeding is insufficiently investigated in the literature. Other significant factors of rebleeding are usually observed in patients requiring ventricular drainage. According to our findings, a causal relationship between EVD and aneurysm rebleeding could be a plausible hypothesis, at least in certain cases.

Hemodynamic Characterization of Geometric Cerebral Aneurysm Templates Treated With Embolic Coils

Embolic coiling is one of the most effective treatments for cerebral aneurysms (CAs), largely due to the hemodynamic modifications that the treatment effects in the aneurysmal environment. However, coiling can have very different hemodynamic outcomes in aneurysms with different geometries. Previous work in the field of biofluid mechanics has demonstrated on a general level that geometry is a driving factor behind aneurysmal hemodynamics. The goal of this study was to relate two specific geometric factors that describe CAs (i.e., dome size (DS) and parent-vessel contact-angle (PV-CA)) and one factor that describes treatment (i.e., coil packing density (PD)) to three clinically relevant hemodynamic responses (i.e., aneurysmal root-mean-square velocity (Vrms), aneurysmal wall shear stress (WSS), and cross-neck flow (CNF)). Idealized models of basilar tip aneurysms were created in both virtual and physical forms to satisfy two-level multifactorial experimental designs. Steady and pulsatile flow hemodynamics were then evaluated in the virtual models using computational fluid dynamics (CFD) (before and after virtual treatment with finite element (FE) embolic coil models), and hemodynamics were also evaluated in the physical models using particle image velocimetry (PIV) (before and after treatment with actual embolic coils). Results showed that among the factors considered, PD made the greatest contributions to effects on hemodynamic responses in and around the aneurysmal sac (i.e., Vrms and WSS), while DS made the greatest contributions to effects on hemodynamics at the neck (i.e., CNF). Results also showed that while a geometric factor (e.g., PV-CA) may play a relatively minor role in dictating hemodynamics in the untreated case, the same factor can play a much greater role after coiling. We consider the significance of these findings in the context of aneurysmal recurrence and rupture, and explore potential roles for the proposed methods in endovascular treatment planning.

Predictors of good functional outcomes and mortality in patients with severe rebleeding after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Aneurysmal rebleeding is a major cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH); however, limited data on severity of rebleeding and outcomes after severe rebleeding are available. We aimed to determine predictors of good outcome and mortality after severe rebleeding.

MATERIALS AND METHODS

In a multicenter poor-grade aneurysm study, 60 patients with severe rebleeding, defined as new hemorrhage with poor clinical condition caused by rebleeding, were identified. Good functional outcome was defined as a modified Rankin scale (mRS) of ≤2, and mortality was defined as a mRS of 6. Multivariate logistic analyses were used to determine predictors of good outcome and mortality.

RESULTS

Of the 58 patients included in this report, 24 (41.3%) patients experienced rebleeding within 24h after ictus. 42 (72.4%) patients had died at 12 months. The rate of good outcome increased from 5.2% at discharge to 13.8% at 6 months and 19.0% at 12 months. In multivariate analysis, World Federation of Neurosurgical Societies (WFNS) grade IV after rebleeding (P=0.007) and aggressive treatment (P=0.039) were independently associated with good outcome. A higher modified Fisher grade before rebledding (P=0.040), larger aneurysms (P=0.005), and lower Glasgow coma score after rebleeding (P=0.003) were independently associated with increased mortality.

CONCLUSIONS

A better clinical condition after rebleeding were independently associated with good outcome and inversely associated with morality after severe rebleeding. Despite high mortality of rebleeding, patients with WFNS grade IV treated with aggressive treatment were more likely to have good outcomes regardless of their condition before rebleeding.

Systolic Blood Pressure Variability is a Novel Risk Factor for Rebleeding in Acute Subarachnoid Hemorrhage: A Case-Control Study

Rebleeding of an aneurysm is a major cause of morbidity and mortality after subarachnoid hemorrhage (SAH). Whereas numerous studies have demonstrated predictors of rebleeding and effect of systolic blood pressure variability (SBPV) on stroke, few data on the association between SBPV and rebleeding. Here, we sought to identify the effect of SBPV on rebleeding in acute aneurysmal SAH. Case-control study. From January 2010 to June 2015, 612 patients with aneurysmal SAH were enrolled in our tertiary care medical center.

MAIN OUTCOME MEASURES

Consecutive patients with acute (<3 days from ictus) aneurismal rebleeding or repair or death were retrospectively included. Antihypertensive therapy based on a predefined standardized protocol was prescribed to lower and maintain SBP between 120 and 160  mm Hg. SBP was measured hourly until a censoring event occurred. SBPV was determined as standard deviation (SD) and successive variation (SV). Binary logistic regression was used to assess the association between SBPV and rebleeding. Rebleeding occurred in 61 (10.0%) of the 612 patients. We identified 47 acute rebleeding as cases and 382 early repair or early death as controls. On binary logistic regression analysis, rebleeding was associated with the SD of SBP (odds ratio [OR], 1.254; 95% confidence interval [CI], 1.131-1.391; P < 0.001) and the SV of SBP (OR, 1.131; 95% CI, 1.039-1.231; P = 0.004). No significant difference was seen between rebleeding and mean systolic blood pressure (MSBP). SBPV is associated with increased rates of acute aneurysmal rebleeding. Further prospective research is warranted to confirm that SBP stability prevents acute aneurysm rebleeding.

Predictive Factors for Rebleeding After Aneurysmal Subarachnoid Hemorrhage: Rebleeding Aneurysmal Subarachnoid Hemorrhage Study

BACKGROUND AND PURPOSE

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating type of stroke associated with high morbidity and mortality. One of the most feared complications is an early rebleeding before aneurysm repair. Predictors for such an often fatal rebleeding are largely unknown. We therefore aimed to determine predictors for an early rebleeding after aSAH in relation with time after ictus.

METHODS

This observational prospective cohort study included all consecutive patients admitted with aSAH between January 1998 and December 2014 (n=1337) at our University Neurovascular Center. Clinical predictors for rebleeding ≤24 hours were identified using multivariable Cox regression analyses. Kaplan-Meier analyses were applied to evaluate the time of rebleeding ≤72 hours after aSAH.

RESULTS

A modified Fisher grade of 3 to 4 was a predictor for an in-hospital rebleeding ≤24 hours after ictus (adjusted hazard ratio, 4.4; 95% confidence interval, 2.1-10.6; P<0.001). The numbers needed to treat to prevent 1 rebleeding ≤24 hours was calculated 15 (95% confidence interval, 10-25). Also, the initiation of external cerebrospinal fluid-drainage (adjusted hazard ratio, 1.9; 95% confidence interval, 1.4-2.5; P<0.001) was independently associated with a rebleeding ≤24 hours. Cumulative in-hospital rebleeding rates were 5.8% ≤24 hours, and 1.2% in the time frame 24-72 hours after ictus.

CONCLUSIONS

In our opinion, timing of treatment of aSAH patients, especially those with an modified Fisher grade of 3 or 4 in a good clinical condition, should be reconsidered. These aSAH patients might be regarded a medical emergency, requiring aneurysm repair as soon as possible. In this respect, our findings should provoke the debate on timing of aneurysm repair, especially in patients considered to be at high risk for rebleeding.