Long-Term Excess Mortality After Aneurysmal Subarachnoid Hemorrhage

Positive Correlation Between Thoracic Aortic Diameter and Intracranial Aneurysm Size-An Observational Cohort Study

OBJECTIVE

To investigate the association between intracranial aneurysms (IAs) and thoracic aortic diameter.

METHODS

This observational cohort study examined thoracic aortic diameters in patients with IA. Patients were categorized by IA size (<7 mm and ≥7 mm) and IA status (ruptured/unruptured) based on radiologic findings. We investigated the association between thoracic aortic diameter and IA size and status using binary and linear regression as univariate and multivariable analyses.

RESULTS

A total of 409 patients were included. Mean age was 60 (±11.7) years and 63% were women. Thoracic aortic diameters were greater among patients who had an IA ≥7 mm versus IA <7 mm (P < 0.05). In the univariate analysis, the diameter of the ascending aorta (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.02-1.129 per 1 mm; P = 0.002), aortic arch (OR, 1.10; 95% CI, 1.04-1.15 per 1 mm; P < 0.001), and descending aorta (OR, 1.10; 95% CI, 1.03-1.16 per 1 mm; P = 0.003) were associated with IAs ≥7 mm. In the multivariable regression model, larger ascending aorta (OR, 1.09; 95% CI, 1.01-1.17 per 1 mm; P = 0.018), aortic arch (OR, 1.12; 95% CI, 1.02-1.22 per 1 mm; P = 0.013), and descending aorta (OR, 1.20; 95% CI, 1.08-1.33 per 1 mm; P < 0.001) were associated with ruptured IA.

CONCLUSIONS

Greater thoracic aortic diameters are associated with a higher risk of IA being larger than 7 mm and IA rupture. Exploring the concomitant growth tendency in IA and thoracic aorta provides a basis for future considerations regarding screening and risk management.

Low and Borderline Ankle-Brachial Index Is Associated With Intracranial Aneurysms: A Retrospective Cohort Study

BACKGROUND AND OBJECTIVES

A low ankle-brachial index (ABI) has been linked to systemic inflammation and an elevated risk of cardiovascular events, most notably myocardial infarction and stroke. Intracranial aneurysms (IAs) share similar risk factors with other cardiovascular diseases. However, the association between low ABI and IAs has not been sufficiently investigated. Our objective was to investigate the potential connection between ABI values and the prevalence of unruptured IAs.

METHODS

This retrospective cohort study reviewed 2751 patients who had ABI measurements at a public tertiary hospital from January 2011 to December 2013. Patients with available cerebrovascular imaging or a diagnosis of ruptured IA were included in the study (n = 776) to examine the association between ABI and saccular IAs. The patients were classified into 4 groups: low ABI (≤0.9, n = 464), borderline ABI (0.91-0.99; n = 47), high ABI (>1.4, n = 57), and normal ABI (1.00-1.40; n = 208).

RESULTS

The prevalence of IAs was 20.3% (18.1% unruptured IAs) in the low ABI group, 14.9% (12.8% unruptured IAs) in the borderline ABI group, 7.0% (5.3% unruptured IAs) in the high ABI group, and 2.4% (1.9% unruptured IAs) in the normal ABI group (P < .001). There were no significant differences in the prevalence of ruptured IAs between the ABI groups (P = .277). Sex- and age-adjusted multinomial regression, including clinically relevant variables, revealed that low ABI (odds ratio [OR], 13.02; 95% CI, 4.01-42.24), borderline ABI (OR, 8.68; 95% CI, 2.05-36.69), and smoking history (OR, 2.01; 95% CI, 1.07-3.77) were associated with unruptured IAs.

CONCLUSION

The prevalence of unruptured IAs was 9-fold higher in the low ABI group and nearly 7-fold higher in the borderline ABI group when compared with the normal ABI group. ABI measurements could be clinically relevant for identifying individuals at higher risk of IAs and may help guide screening and preventive strategies.

Risks of nimodipine dose reduction during the high-risk period for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

Nimodipine dose reduction is recommended in case of high vasopressor demand after aneurysmal subarachnoid hemorrhage (aSAH). The aim of this study was to assess potential adverse effects of nimodipine reduction during the high-risk period for delayed cerebral ischemia (DCI) and cerebral vasospasm (CVS) between days 5 and 10 after hemorrhage. Demographic and clinical data as well as daily nimodipine dose of aSAH patients admitted between 2010 and 2019 were retrospectively analyzed. Univariable and multivariable regression analyses were performed to identify factors associated with DCI, angiographic CVS, DCI-related infarction, and unfavorable outcome. A total of 205 patients were included. Nimodipine dose reduction occurred in 108 (53%) patients ('nimodipine reduction group'), while 97 patients (47%) received the full dose ('no nimodipine reduction group'), Patients in the 'nimodipine reduction group' had significant worse WFNS and Fisher grades and developed significantly more often DCI and angiographic CVS. DCI-related infarction and unfavorable outcome were also significantly increased in the 'nimodipine reduction group.' 'Reduced nimodipine dose' was the only independent predictor for the occurrence of DCI and angiographic CVS in multivariable regression analysis. 'Poor WFNS grade' and 'reduced nimodipine dose' were identified as independent risk factors for DCI-related infarction while 'older age,' 'poor WFNS grade,' and 'reduced nimodipine dose' were associated with unfavorable outcome at 3 months after discharge. Nimodipine dose reduction during the high-risk period of DCI and CVS between days 5 and 10 after hemorrhage might abrogate the positive prognostic effects of nimodipine and should be critically evaluated.

Cost-effectiveness of WEB Embolization, Coiling and Stent-assisted Coiling for the Treatment of Unruptured Intracranial Aneurysms

PURPOSE

Information about the cost-effectiveness of a certain treatment is relevant for decision-making and healthcare providers. This study compares the cost-effectiveness of the novel Woven Endobridge (WEB) for intracranial aneurysm treatment with conventional coiling and stent-assisted coiling (SAC) from the perspective of the German Statutory Health Insurance.

METHODS

A patient-level simulation was constructed to simulate 55-year-old patients with an unruptured middle cerebral artery aneurysm (size: 3-11 mm) considering WEB treatment, coiling or SAC in terms of morbidity, angiographic outcome, retreatment, procedural and rehabilitation costs and rupture rates. Incremental cost-effectiveness ratios (ICERs) were calculated as costs per quality-adjusted life years (QALYs) and costs per year with neurologic morbidity avoided. Uncertainty was explored with deterministic and probabilistic sensitivity analyses. The majority of data were obtained from prospective multi-center studies and meta-analyses of non-randomized studies.

RESULTS

In the base case, lifetime QALYs were 13.24 for the WEB, 12.92 for SAC and 12.68 for coiling. Lifetime costs were 20,440 € for the WEB, 23,167 € for SAC, and 8200 € for coiling. Compared to coiling, the ICER for the WEB was 21,826 €/QALY, while SAC was absolutely dominated by WEB. Probabilistic sensitivity analysis revealed that at a willingness-to-pay of ≥ 30,000 €/QALY, WEB was the preferred treatment. Deterministic sampling showed that the discount rate, material costs and retreatment rates had the largest impact on the ICERs.

CONCLUSION

The novel WEB showed at least comparable cost-effectiveness to SAC for treatment of broad-based unruptured aneurysms. Considering all three modalities, coiling had the least costs; however this modality is often not appropriate for the treatment of wide-necked aneurysms.

Adverse events during endovascular treatment of ruptured aneurysms: A prospective nationwide study on subarachnoid hemorrhage in Sweden

Introduction

A range of adverse events (AEs) may occur in patients with subarachnoid hemorrhage (SAH). Endovascular treatment is commonly used to prevent aneurysm re-rupture.

Research question

The aim of this study was to identify AEs related to endovascular treatment, analyze risk factors for AEs and how AEs affect patient outcome.

Material and methods

Patients with aneurysmal SAH admitted to all neurosurgical centers in Sweden during a 3.5-year period (2014-2018) were prospectively registered. AEs related to endovascular aneurysm treatment were thromboembolic events, aneurysm re-rupture, vessel dissection and puncture site hematoma. Potential risk factors for the AEs were analyzed using multivariate logistic regression. Functional outcome was assessed at one year using the extended Glasgow outcome scale.

Results

In total, 1037 patients were treated for ruptured aneurysms. Of which, 715 patients were treated with endovascular occlusion. There were 115 AEs reported in 113 patients (16%). Thromboembolic events were noted in 78 patients (11%). Aneurysm re-rupture occurred in 28 (4%), vessel dissection in 4 (0.6%) and puncture site hematoma in 5 (0.7%). Blister type aneurysm, aneurysm smaller than 5 mm and endovascular techniques other than coiling were risk factors for treatment-related AEs. At follow-up, 230 (32%) of the patients had unfavorable outcome. Patients suffering intraprocedural aneurysm re-rupture were more likely to have unfavorable outcome (OR 6.9, 95% CI 2.3-20.9).

Discussion and conclusion

Adverse events related to endovascular occlusion of a ruptured aneurysm were seen in 16% of patients. Aneurysm re-rupture during endovascular treatment was associated with increased risk of unfavorable functional outcome.

Association between neutrophil-to-albumin ratio and long-term mortality of aneurysmal subarachnoid hemorrhage

OBJECTIVE

The prognosis of aneurysmal subarachnoid hemorrhage (aSAH) survivors is concerning. The goal of this study was to investigate and demonstrate the relationship between the neutrophil-to-albumin ratio (NAR) and long-term mortality of aSAH survivors.

METHODS

A retrospective observational cohort study was conducted at Sichuan University West China Hospital between January 2009 and June 2019. The investigation of relationship between NAR and long-term mortality was conducted using univariable and multivariable Cox regression models. To demonstrate the predictive performance of different biomarkers over time, time-dependent receiver operating characteristic curve (ROC) analysis and decision curve analysis (DCA) were created.

RESULTS

In total, 3173 aSAH patients were included in this study. There was a strong and continuous relationship between NAR levels and long-term mortality (HR 3.23 95% CI 2.75-3.79, p < 0.001). After adjustment, the result was still significant (adjusted HR 1.78 95% CI 1.49-2.12). Compared with patients with the lowest quartile (< 0.15) of NAR levels, the risk of long-term mortality in the other groups was higher (0.15-0.20: adjusted HR 1.30 95% CI 0.97-1.73; 0.20-0.28: adjusted HR 1.37 95% CI 1.03-1.82; >0.28: adjusted HR 1.74 95% CI 1.30-2.32). Results in survivors were found to be still robust. Moreover, out of all the inflammatory markers studied, NAR demonstrated the highest correlation with long-term mortality.

CONCLUSIONS

A high level of NAR was associated with increased long-term mortality among patients with aSAH. NAR was a promising inflammatory marker for long-term mortality of aSAH.

Cerebrospinal Fluid and Serum Biomarker Insights in Aneurysmal Subarachnoid Haemorrhage: Navigating the Brain-Heart Interrelationship for Improved Patient Outcomes

The pathophysiological mechanisms underlying severe cardiac dysfunction after aneurysmal subarachnoid haemorrhage (aSAH) remain poorly understood. In the present study, we focused on two categories of contributing factors describing the brain-heart relationship. The first group includes brain-specific cerebrospinal fluid (CSF) and serum biomarkers, as well as cardiac-specific biomarkers. The secondary category encompasses parameters associated with cerebral autoregulation and the autonomic nervous system. A group of 15 aSAH patients were included in the analysis. Severe cardiac complications were diagnosed in seven (47%) of patients. In the whole population, a significant correlation was observed between CSF S100 calcium-binding protein B (S100B) and brain natriuretic peptide (BNP) (rS = 0.62; p = 0.040). Additionally, we identified a significant correlation between CSF neuron-specific enolase (NSE) with cardiac troponin I (rS = 0.57; p = 0.025) and BNP (rS = 0.66; p = 0.029), as well as between CSF tau protein and BNP (rS = 0.78; p = 0.039). Patients experiencing severe cardiac complications exhibited notably higher levels of serum tau protein at day 1 (0.21 ± 0.23 [ng/mL]) compared to those without severe cardiac complications (0.03 ± 0.04 [ng/mL]); p = 0.009. Impaired cerebral autoregulation was noted in patients both with and without severe cardiac complications. Elevated serum NSE at day 1 was related to impaired cerebral autoregulation (rS = 0.90; p = 0.037). On the first day, a substantial, reciprocal correlation between heart rate variability low-to-high frequency ratio (HRV LF/HF) and both GFAP (rS = -0.83; p = 0.004) and S100B (rS = -0.83; p = 0.004) was observed. Cardiac and brain-specific biomarkers hold the potential to assist clinicians in providing timely insights into cardiac complications, and therefore they contribute to the prognosis of outcomes.

Limitations of prone positioning in patients with aneurysmal subarachnoid hemorrhage and concomitant respiratory failure

OBJECTIVE

Prone positioning (PP) is an established treatment modality for respiratory failure. After aneurysmal subarachnoid hemorrhage (aSAH), PP is rarely performed considering the risk of intracranial hypertension. The aim of this study was to analyze the effects of PP on intracranial pressure (ICP), cerebral perfusion pressure (CPP) and cerebral oxygenation following aSAH.

PATIENTS AND METHODS

Demographic and clinical data of aSAH patients admitted over a 6-year period and treated with PP due to respiratory insufficiency were retrospectively analyzed. ICP, CPP, brain tissue oxygenation (pBrO2), respiratory parameters and ventilator settings were analyzed before and during PP.

RESULTS

Thirty patients receiving invasive multimodal neuromonitoring were included. Overall, 97 PP sessions were performed. Mean arterial oxygenation and pBrO2 increased significantly during PP. We found a significant increase in median ICP compared to the baseline level in supine position. No significant changes in CPP were observed. Five PP sessions had to be terminated early due to medically refractory ICP-crisis. The affected patients were younger (p = 0.02) with significantly higher baseline ICP values (p = 0.009). Baseline ICP correlates significantly (p < 0.001) with ICP 1 h (R: 0.57) and 4 h (R: 0.55) after onset of PP.

CONCLUSION

PP in aSAH patients with respiratory insufficiency is an effective therapeutic option improving arterial and global cerebral oxygenation without compromising CPP. The significant increase in ICP was moderate in most sessions. However, as some patients experience intolerable ICP crises during PP, continuous ICP-Monitoring is considered mandatory. Patients with elevated baseline ICP and reduced intracranial compliance should not be considered for PP.

Adverse events associated with microsurgial treatment for ruptured intracerebral aneurysms: a prospective nationwide study on subarachnoid haemorrhage in Sweden

BACKGROUND

Adverse events (AEs) or complications may arise secondary to the treatment of aneurysmal subarachnoid haemorrhage (SAH). The aim of this study was to identify AEs associated with microsurgical occlusion of ruptured aneurysms, as well as to analyse their risk factors and impact on functional outcome.

METHODS

Patients with aneurysmal SAH admitted to the neurosurgical centres in Sweden were prospectively registered during a 3.5-year period (2014-2018). AEs were categorised as intraoperative or postoperative. A range of variables from patient history and SAH characteristics were explored as potential risk factors for an AE. Functional outcome was assessed approximately 1 year after the bleeding using the extended Glasgow Outcome Scale.

RESULTS

In total, 1037 patients were treated for ruptured aneurysms, of which, 322 patients were treated with microsurgery. There were 105 surgical AEs in 97 patients (30%); 94 were intraoperative AEs in 79 patients (25%). Aneurysm rerupture occurred in 43 patients (13%), temporary occlusion of the parent artery >5 min in 26 patients (8%) and adjacent vessel injury in 25 patients (8%). High Fisher grade and brain oedema on CT were related to increased risk of AEs. At follow-up, 38% of patients had unfavourable outcome. Patients suffering AEs were more likely to have unfavourable outcome (OR 2.3, 95% CI 1.10 to 4.69).

CONCLUSION

Intraoperative AEs occurred in 25% of patients treated with microsurgery for ruptured intracerebral aneurysm in this nationwide survey. Although most operated patients had favourable outcome, AEs were associated with increased risk of unfavourable outcome.

Quality of Life After Poor-Grade Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Poor-grade aneurysmal subarachnoid hemorrhage (aSAH) is associated with high mortality and poor disability outcome. Data on quality of life (QoL) among survivors are scarce because patients with poor-grade aSAH are underrepresented in clinical studies reporting on QoL after aSAH.

OBJECTIVE

To provide prospective QoL data on survivors of poor-grade aSAH to aid clinical decision making and counseling of relatives.

METHODS

The herniation World Federation of Neurosurgical Societies scale study was a prospective observational multicenter study in patients with poor-grade (World Federation of Neurosurgical Societies grades 4 & 5) aSAH. We collected data during a structured telephone interview 6 and 12 months after ictus. QoL was measured using the EuroQoL - 5 Dimensions - 3 Levels (EQ-5D-3L) questionnaire, with 0 representing a health state equivalent to death and 1 to perfect health. Disability outcome for favorable and unfavorable outcomes was measured with the modified Rankin Scale.

RESULTS

Two hundred-fifty patients were enrolled, of whom 237 were included in the analysis after 6 months and 223 after 12 months. After 6 months, 118 (49.8%) patients were alive, and after 12 months, 104 (46.6%) patients were alive. Of those, 95 (80.5%) and 89 (85.6%) reached a favorable outcome with mean EQ-5D-3L index values of 0.85 (±0.18) and 0.86 (±0.18). After 6 and 12 months, 23 (19.5%) and 15 (14.4%) of those alive had an unfavorable outcome with mean EQ-5D-3L index values of 0.27 (±0.25) and 0.19 (±0.14).

CONCLUSION

Despite high initial mortality, the proportion of poor-grade aSAH survivors with good QoL is reasonably large. Only a minority of survivors reports poor QoL and requires permanent care.

Cost-effectiveness of thrombectomy in patients with minor stroke and large vessel occlusion: effect of thrombus location on cost-effectiveness and outcomes

BACKGROUND

To evaluate the cost-effectiveness of endovascular thrombectomy (EVT) to treat large vessel occlusion (LVO) in patients with acute, minor stroke (National Institute of Health Stroke Scale (NIHSS) <6) and impact of occlusion site.

METHODS

A Markov decision-analytic model was constructed accounting for both costs and outcomes from a societal perspective. Two different management strategies were evaluated: EVT and medical management. Base case analysis was done for three different sites of occlusion: proximal M1, distal M1 and M2 occlusions. One-way, two-way and probabilistic sensitivity analyses were performed.

RESULTS

Base-case calculation showed EVT to be the dominant strategy in 65-year-old patients with proximal M1 occlusion and NIHSS <6, with lower cost (US$37 229 per patient) and higher effectiveness (1.47 quality-adjusted life years (QALYs)), equivalent to 537 days in perfect health or 603 days in modified Rankin score (mRS) 0-2 health state. EVT is the cost-effective strategy in 92.7% of iterations for patients with proximal M1 occlusion using a willingness-to-pay threshold of US$100 000/QALY. EVT was cost-effective if it had better outcomes in 2%-3% more patients than intravenous thrombolysis (IVT) in absolute numbers (base case difference -16%). EVT was cost-effective when the proportion of M2 occlusions was less than 37.1%.

CONCLUSIONS

EVT is cost-effective in patients with minor stroke and LVO in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with non-reperfusion. Our study emphasizes the need for caution in interpreting previous observational studies which concluded similar results in EVT versus medical management in patients with minor stroke due to a high proportion of patients with M2 occlusions in the two strategies.

Surveillance of Unruptured Intracranial Aneurysms: Cost-Effectiveness Analysis for 3 Countries

BACKGROUND AND OBJECTIVES

No consensus exists on adequate surveillance of conservatively managed unruptured intracranial aneurysms (UIAs). We aimed to determine optimal MRI surveillance strategies for the growth of UIAs using cost-effectiveness analysis. A secondary aim was to develop a clinical tool for personalizing UIA surveillance.

METHODS

We designed a microsimulation model from a health care perspective simulating 100,000 55-year-old women to estimate costs and quality-adjusted life years (QALYs) over a lifetime horizon in the United States, the United Kingdom, and the Netherlands, using literature-derived model parameters. Country-specific costs and willingness-to-pay thresholds ($100,000/QALY for the United States, £30,000/QALY for the United Kingdom, and €80,000/QALY for the Netherlands) were used. Lifetime costs and QALYs were annually discounted at 3% for the United States, 3.5% for the United Kingdom, or 4% (costs) and 1.5% (QALYs) for the Netherlands. Strategies were no follow-up surveillance, follow-up with MRI in the first and fifth year after UIA discovery, every 5 years, every 2 years, or annually, or immediate intervention (i.e., clipping or coiling). Using the microsimulation model, we developed a tool for personalizing UIA surveillance for men and women, with different ages and varying aneurysm characteristics. Uncertainty in the input parameters was modeled with probabilistic sensitivity analysis.

RESULTS

Among 55-year-old women, 2,222 individuals in the United States, 1,910 in the United Kingdom, and 2,040 in the Netherlands needed to undergo an annual MRI scan to prevent 1 case of subarachnoid hemorrhage per year. No surveillance MRI was most cost-effective in the United States (in 47% of the simulations) and United Kingdom (in 54% of simulations), whereas annual MRI was most cost-effective in the Netherlands (in 53% of simulations). In the United States and United Kingdom, annual surveillance or surveillance in the first and fifth year after discovery was cost-effective in patients <60 years and at increased risk of aneurysm growth. The optimal, personalized, surveillance strategies were summarized in a look-up table for use in clinical practice.

DISCUSSION

Generally, the US and UK physicians should refrain from assigning patients, particularly older patients and those with few risk factors for aneurysm growth or rupture, to frequent MRI surveillance. In the Netherlands, annual follow-up is generally most cost-effective.

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.

[Outcomes of patients experiencing cardiovascular adverse events within 1 year following craniotomy for intracranial aneurysm clipping: a retrospective cohort study]

OBJECTIVE

To investigate the impact of postoperative serious cardiovascular adverse events (CAE) on outcomes of patients undergoing craniotomy for intracranial aneurysm clipping.

METHODS

This retrospective cohort study was conducted among the patients undergoing craniotomy for intracranial aneurysm clipping during the period from December, 2016 to December, 2017, who were divided into CAE group and non-CAE group according to the occurrence of Clavien-Dindo grade ≥II CAEs after the surgery. The perioperative clinical characteristics of the patients, complications and neurological functions during hospitalization, and mortality and neurological functions at 1 year postoperatively were evaluated. The primary outcome was mortality within 1 year after the surgery. The secondary outcomes were Glasgow outcome scale (GOS) score at 1 year, lengths of postoperative hospital and intensive care unit (ICU) stay, and Glasgow coma scale (GCS) score at discharge.

RESULTS

A total of 361 patients were enrolled in the final analysis, including 20 (5.5%) patients in CAE group and 341 in the non-CAE group. No significant differences were found in the patients' demographic characteristics, clinical history, or other postoperative adverse events between the two groups. The 1-year mortality was significantly higher in CAE group than in the non-CAE group (20.0% vs 5.6%, P=0.01). Logistics regression analysis showed that when adjusted for age, gender, emergency hospitalization, subarachnoid hemorrhage, volume of bleeding, duration of operation, aneurysm location, and preoperative history of cardiovascular disease, postoperative CAEs of Clavien-Dindo grade≥II was independently correlated with 1-year mortality rate of the patients with an adjusted odds ratio of 3.670 (95% CI: 1.037-12.992, P=0.04). The patients with CEA also had a lower GOS score at 1 year after surgery than those without CEA (P=0.002). No significant differences were found in the occurrence of other adverse events, postoperative hospital stay, ICU stay, or GCS scores at discharge between the two groups (P > 0.05).

CONCLUSION

Postoperative CAEs may be a risk factor for increased 1-year mortality and disability in patients undergoing craniotomy for intracranial aneurysms.

Impact of collateral flow on cost-effectiveness of endovascular thrombectomy

OBJECTIVE

Acute ischemic stroke patients with large-vessel occlusion and good collateral blood flow have significantly better outcomes than patients with poor collateral circulation. The purpose of this study was to evaluate the cost-effectiveness of endovascular thrombectomy (EVT) based on collateral status and, in particular, to analyze its effectiveness in ischemic stroke patients with poor collaterals.

METHODS

A decision analysis study was performed with Markov modeling to estimate the lifetime quality-adjusted life-years (QALYs) and associated costs of EVT based on collateral status. The study was performed over a lifetime horizon with a societal perspective in the US setting. Base-case analysis was done for good, intermediate, and poor collateral status. One-way, two-way, and probabilistic sensitivity analyses were performed.

RESULTS

EVT resulted in greater effectiveness of treatment compared to no EVT/medical therapy (2.56 QALYs in patients with good collaterals, 1.88 QALYs in those with intermediate collaterals, and 1.79 QALYs in patients with poor collaterals), which was equivalent to 1050, 771, and 734 days, respectively, in a health state characterized by a modified Rankin Scale (mRS) score of 0-2. EVT also resulted in lower costs in patients with good and intermediate collaterals. For patients with poor collateral status, the EVT strategy had higher effectiveness and higher costs, with an incremental cost-effectiveness ratio (ICER) of $44,326/QALY. EVT was more cost-effective as long as it had better outcomes in absolute numbers in at least 4%-8% more patients than medical management.

CONCLUSIONS

EVT treatment in the early time window for good outcome after ischemic stroke is cost-effective irrespective of the quality of collateral circulation, and patients should not be excluded from thrombectomy solely on the basis of collateral status. Despite relatively lower benefits of EVT in patients with poor collaterals, even smaller differences in better outcomes have significant long-term financial implications that make EVT cost-effective.

Preoperative predictors of poor outcomes in Thai patients with aneurysmal subarachnoid hemorrhage

Objective

A scoring system for aneurysmal subarachnoid hemorrhage (aSAH) is useful for guiding treatment decisions, especially in urgent-care limited settings. This study developed a simple algorithm of clinical conditions and grading to predict outcomes in patients treated by clipping or coiling.

Methods

Data on patients with aSAH hospitalized in a university’s neurovascular center in Thailand from 2013 to 2018 were obtained for chart review. Factors associated with poor outcomes evaluated at one year were identified using a stepwise logistic regression model. For each patient, the rounded regression coefficients of independent risk factors were linearly combined into a total score, which was assessed for its performance in predicting outcomes using receiver operating characteristic analysis. An appropriate cutoff point of the scores for poor outcomes was based on Youden’s criteria, which maximized the summation between sensitivity or true positive rate and the specificity or true negative rate.

Results

Patients (n, 121) with poor outcomes (modified Rankin Scale, mRS score, 4–6) had a significantly higher proportion of old age, underlying hypertension, diabetes and chronic kidney disease, high clinical severity grading, preoperative rebleeding, and hydrocephalus than those (n, 336) with good outcomes (mRS score, 0–3). Six variables, including age >70 years, diabetes mellitus, World Federation of Neurosurgical Societies (WFNS) scaling of IV-V, modified Fisher grading of 3–4, rebleeding, and hydrocephalus, were identified as independent risk factors and were assigned a score weight of 2, 1, 2, 1, 3 and 1, respectively. Among the total possible scores ranging from 0–10, the cut point at score 3 yielded the maximum Youden’s index (0.527), which resulted in a sensitivity of 77.7% and specificity of 75.0%.

Conclusion

A simple 0–10 scoring system on six risk factors for poor outcomes was validated for aSAH and should be advocated for use in limited resource settings.

Association between D-dimer levels and long-term mortality in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

D-dimer is a marker for hypercoagulability and thrombotic events. The authors sought to investigate whether D-dimer levels predicted long-term mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

This was a retrospective study of patients with aSAH in West China Hospital, Sichuan University, between December 2013 and June 2019. D-dimer levels were measured within 24 hours after admission and were grouped by quartiles. The primary outcome was long-term mortality. Patient deaths were determined through the Household Registration Administration System in China, with a median of 4.4 years of follow-up.

RESULTS

This study included 2056 patients. Compared with patients with the lowest quartile (0.00-0.97 mg/L) of D-dimer levels, the odds of long-term mortality were significantly higher in all other patients, including those with D-dimer levels between 0.97 mg/L and 1.94 mg/L (adjusted hazard ratio [aHR] 1.85, 95% CI 1.32-2.60), those with D-dimer levels between 1.94 mg/L and 4.18 mg/L (aHR 1.94, 95% CI 1.40-2.70), and those patients with the highest quartile (> 4.18 mg/L) of D-dimer levels (aHR 2.35, 95% CI 1.70-3.24; p < 0.001). Similar results were observed for the endpoints of 1-year mortality and long-term mortality in 1-year survivors.

CONCLUSIONS

Elevated D-dimer levels at admission were associated with short-term and long-term mortality. This biomarker could be considered in future risk nomograms for long-term outcomes and might support future management decisions.

External Validation of a Neural Network Model in Aneurysmal Subarachnoid Hemorrhage: A Comparison With Conventional Logistic Regression Models

BACKGROUND

Interest in machine learning (ML)-based predictive modeling has led to the development of models predicting outcomes after aneurysmal subarachnoid hemorrhage (aSAH), including the Nijmegen acute subarachnoid hemorrhage calculator (Nutshell). Generalizability of such models to external data remains unclear.

OBJECTIVE

To externally validate the performance of the Nutshell tool while comparing it with the conventional Subarachnoid Hemorrhage International Trialists (SAHIT) models and to review the ML literature on outcome prediction after aSAH and aneurysm treatment.

METHODS

A prospectively maintained database of patients with aSAH presenting consecutively to our institution in the 2013 to 2018 period was used. The web-based Nutshell and SAHIT calculators were used to derive the risks of poor long-term (12-18 months) outcomes and 30-day mortality. Discrimination was evaluated using the area under the curve (AUC), and calibration was investigated using calibration plots. The literature on relevant ML models was surveyed for a synopsis.

RESULTS

In 269 patients with aSAH, the SAHIT models outperformed the Nutshell tool (AUC: 0.786 vs 0.689, P = .025) in predicting long-term functional outcomes. A logistic regression model of the Nutshell variables derived from our data achieved adequate discrimination (AUC = 0.759) of poor outcomes. The SAHIT models outperformed the Nutshell tool in predicting 30-day mortality (AUC: 0.810 vs 0.636, P < .001). Calibration properties were more favorable for the SAHIT models. Most published aneurysm-related ML-based outcome models lack external validation and usable testing platforms.

CONCLUSION

The Nutshell tool demonstrated limited performance on external validation in comparison with the SAHIT models. External validation and the dissemination of testing platforms for ML models must be emphasized.

Management of Unruptured Small Multiple Intracranial Aneurysms in China: A Comparative Effectiveness Analysis Based on Real-World Data

Background

Unruptured small aneurysms with a size of <7 mm were often followed conservatively. However, it is unknown whether unruptured small multiple intracranial aneurysms (MIAs) are better to be prophylactically treated or conservatively followed.

Objective

We aim to compare the effectiveness of different strategies regarding their management.

Methods

A decision-analytic Markov model was built over a entire life cycle. The compared strategies include natural history, treat one aneurysm, treat both aneurysms, annual follow-up, biennial follow-up, and follow-up every 5 years. The inputs for the model were obtained from real-world data and related medical literature. Outcomes were measured in terms of quality-adjusted life-years (QALYs).

Results

Treat both aneurysms had the highest effectiveness of 15.36 QALYs and treat one aneurysm had the second-highest effectiveness of 15.11 QALYs. Probabilistic sensitivity analysis with 10,000 iterations showed that treat both aneurysms and treat one aneurysm were optimal in 67.28 and 17.91% of all cases, respectively. One-way and two-way sensitivity analyses showed that the result was sensitive to the proportion of moderate to severe disability after treating two aneurysms, mortality after treating two aneurysms, proportion of moderate to severe disability after treating one aneurysm, and rupture rate of small growing aneurysm. Either treat both aneurysms or treat one aneurysm would be the optimal strategy under most of the circumstances with the variations of these parameters.

Conclusion

For patients with small unruptured MIAs, prophylactic coiling was superior to conservative management and at least one aneurysm should be treated.

Long-Term Risk of Ischemic Stroke among Elderly Survivors of Non-Traumatic Subarachnoid Hemorrhage

INTRODUCTION

Non-traumatic subarachnoid hemorrhage (SAH) is associated with poor long-term functional outcomes, but the risk of ischemic stroke among SAH survivors is poorly understood.

OBJECTIVES

The aim of this study was to evaluate the risk of ischemic stroke among survivors of SAH.

METHODS

We performed a retrospective cohort study using claims data from Medicare beneficiaries from 2008 to 2015. The exposure was a diagnosis of SAH, while the outcome was an acute ischemic stroke, both identified using previously validated ICD-9-CM diagnosis codes. We used Cox regression analysis adjusting for demographics and stroke risk factors to evaluate the association between SAH and long-term risk of ischemic stroke.

RESULTS

Among 1.7 million Medicare beneficiaries, 912 were hospitalized with non-traumatic SAH. During a median follow-up of 5.2 years (IQR, 2.7-6.7), the cumulative incidence of ischemic stroke was 22 per 1,000 patients per year among patients with SAH, and 7 per 1,000 patients per year in those without SAH. In adjusted Cox models, SAH was associated with an increased risk of ischemic stroke (HR, 2.0; 95% confidence interval, 1.4-2.8) as compared to beneficiaries without SAH. Similar results were obtained in sensitivity analyses, when treating death as a competing risk (sub HR, 3.0; 95% CI, 2.8-3.3) and after excluding ischemic stroke within 30 days of SAH discharge (HR, 1.5; 95% CI, 1.1-2.3).

CONCLUSIONS

In a large, heterogeneous national cohort of elderly patients, survivors of SAH had double the long-term risk of ischemic stroke. SAH survivors should be closely monitored and risk stratified for ischemic stroke.

Spontaneous angiogram-negative subarachnoid hemorrhage: a retrospective single center cohort study

Background

Spontaneous angiogram-negative subarachnoid hemorrhage (SAH) is considered a benign illness with little of the aneurysmal SAH-related complications. We describe the clinical course, SAH-related complications, and outcome of patients with angiogram-negative SAH.

Methods

We retrospectively reviewed all adult patients admitted to a neurosurgical intensive care unit during 2004–2018 due to spontaneous angiogram-negative SAH. Our primary outcome was a dichotomized Glasgow Outcome Scale (GOS) at 3 months. We assessed factors that associated with outcome using multivariable logistic regression analysis.

Results

Of the 108 patients included, 84% had a favorable outcome (GOS 4–5), and mortality was 5% within 1 year. The median age was 58 years, 51% were female, and 93% had a low-grade SAH (World Federation of Neurosurgical Societies grading I–III). The median number of angiograms performed per patient was two. Thirty percent of patients showed radiological signs of acute hydrocephalus, 28% were acutely treated with an external ventricular drain, 13% received active vasospasm treatment and 17% received a permanent shunt. In the multivariable logistic regression model, only acute hydrocephalus associated with unfavorable outcome (odds ratio = 4.05, 95% confidence interval = 1.05–15.73). Two patients had a new bleeding episode.

Conclusion

SAH-related complications such as hydrocephalus and vasospasm are common after angiogram-negative SAH. Still, most patients had a favorable outcome. Only acute hydrocephalus was associated with unfavorable outcome. The high rate of SAH-related complications highlights the need for neurosurgical care in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-05069-7.

Case-Fatality and Functional Outcome after Subarachnoid Hemorrhage (SAH) in INternational STRoke oUtComes sTudy (INSTRUCT)

BACKGROUND

There are few large population-based studies of outcomes after subarachnoid hemorrhage (SAH) than other stroke types.

METHODS

We pooled data from 13 population-based stroke incidence studies (10 studies from the INternational STRroke oUtComes sTudy (INSTRUCT) and 3 new studies; N=657). Primary outcomes were case-fatality and functional outcome (modified Rankin scale score 3-5 [poor] vs. 0-2 [good]). Harmonized patient-level factors included age, sex, health behaviours (e.g. current smoking at baseline), comorbidities (e.g.history of hypertension), baseline stroke severity (e.g. NIHSS >7) and year of stroke. We estimated predictors of case-fatality and functional outcome using Poisson regression and generalized estimating equations using log-binomial models respectively at multiple timepoints.

RESULTS

Case-fatality rate was 33% at 1 month, 43% at 1 year, and 47% at 5 years. Poor functional outcome was present in 27% of survivors at 1 month and 15% at 1 year. In multivariable analysis, predictors of death at 1-month were age (per decade increase MRR 1.14 [1.07-1.22]) and SAH severity (MRR 1.87 [1.50-2.33]); at 1 year were age (MRR 1.53 [1.34-1.56]), current smoking (MRR 1.82 [1.20-2.72]) and SAH severity (MRR 3.00 [2.06-4.33]) and; at 5 years were age (MRR 1.63 [1.45-1.84]), current smoking (MRR 2.29 [1.54-3.46]) and severity of SAH (MRR 2.10 [1.44-3.05]). Predictors of poor functional outcome at 1 month were age (per decade increase RR 1.32 [1.11-1.56]) and SAH severity (RR 1.85 [1.06-3.23]), and SAH severity (RR 7.09 [3.17-15.85]) at 1 year.

CONCLUSION

Although age is a non-modifiable risk factor for poor outcomes after SAH, however, severity of SAH and smoking are potential targets to improve the outcomes.

Cost-effectiveness of endovascular thrombectomy in patients with acute stroke and M2 occlusion

BACKGROUND

The cost-effectiveness of endovascular thrombectomy (EVT) in patients with acute ischemic stroke due to M2 branch occlusion remains uncertain.

OBJECTIVE

To evaluate the cost-effectiveness of EVT compared with medical management in patients with acute stroke presenting with M2 occlusion using a decision-analytic model.

METHODS

A decision-analytic study was performed with Markov modeling to estimate the lifetime quality-adjusted life years and associated costs of EVT-treated patients compared with no-EVT/medical management. The study was performed over a lifetime horizon with a societal perspective in the Unites States setting. Base case, one-way, two-way, and probabilistic sensitivity analyses were performed.

RESULTS

EVT was the long-term cost-effective strategy in 93.37% of the iterations in the probabilistic sensitivity analysis, and resulted in difference in health benefit of 1.66 QALYs in the 65-year-old age groups, equivalent to 606 days in perfect health. Varying the outcomes after both strategies shows that EVT was more cost-effective when the probability of good outcome after EVT was only 4-6% higher relative to medical management in clinically likely scenarios. EVT remained cost-effective even when its cost exceeded US$200 000 (threshold was US$209 111). EVT was even more cost-effective for 55-year-olds than for 65-year-old patients.

CONCLUSION

Our study suggests that EVT is cost-effective for treatment of acute M2 branch occlusions. Faster and improved reperfusion techniques would increase the relative cost-effectiveness of EVT even further in these patients.

Intracranial aneurysm is predicted by abdominal aortic calcification index: A retrospective case-control study

BACKGROUND AND AIMS

Patients with intracranial aneurysms (IA) have excess mortality for cardiovascular diseases, but little is known on whether atherosclerotic manifestations and IA coexist. We investigated abdominal aortic calcification index (ACI) association with unruptured and ruptured IAs.

METHODS

This retrospective case-control study reviews all tertiary centers patients (n = 24,660) who had undergone head computed tomography angiography (CTA), magnetic resonance angiography (MRA) or digital subtraction angiography (DSA) for any reason between January 2003 and May 2018. Patients (n = 2020) with unruptured or ruptured IAs were identified, and patients with available abdominal CT were included. IA patients were matched by sex and age to controls (available abdomen CT, no IAs) in ratio of 1:3. ACI was measured from abdomen CT scans and patient records were reviewed.

RESULTS

1720 patients (216 ruptured IA (rIA), 246 unruptured IA (UIA) and 1258 control) were included. Mean age was 62.9 ± 11.9 years and 58.2% were female. ACI (OR 1.02 per increment, 95%CI 1.01-1.03) and ACI>3 (OR 5.77, 95%CI 3.29-10.11) increased risk for rIA compared to matched controls. UIA patients' ACI was significantly higher but ACI did not increase odds for UIA compared to matched controls. History of coronary artery disease was less frequent in rIA patients. There was no calcification in aorta in 8.8% rIA and 13.6% UIA patients (matched controls 25.7% and 22.6% respectively, p < 0.01).

CONCLUSIONS

Aortic calcification is greater in rIA and UIA patients than matched controls. ACI increases risk for rIAs.

Efficacy of an intervention program to prevent patient safety indicators in aneurysmal subarachnoid haemorrhage

OBJECTIVE

Patient safety indicators (PSI) are a set of potentially preventable events related to patient safety and opportunities for improvement. Eight pertinent PSI have been identified in patients with aneurysmal subarachnoid haemorrhage (ASAH), such as decubitus ulcer, and central line-related bacteraemia. Our aim was to evaluate the efficacy of a health care quality protocol to prevent the appearance of PSI in ASAH patients.

METHODS

Adult patients treated for ASAH were included in a retrospective control group of 35 patients and a prospective experimental group of 35 patients when the prevention program was implemented. We evaluated the occurrence of PSI, and its relation to age, sex, Hunt and Hess scale grade, type of aneurysm treatment, length of hospital stay, and Glasgow Outcome Scale scores.

RESULTS

Both groups had similar characteristics except for a longer hospital stay in the control group. The overall PSI prevalence decreased significantly in the experimental group compared to the control group. The experimental group had a decreased risk for having at least one PSI: OR = 0.21 (0.08-0.57, CI 95%). The absolute risk reduction is 37.1% (58.9%-15.4%), the preventable fraction for the population is 28.3% (10.6%-40.0%), and the number needed to treat is 2.69.

CONCLUSIONS

The health care quality protocol is effective to prevent ISP in ASAH patients. Implementing this prevention program has no effect on the neurological state of the patient at the hospital discharge. Still, it is successful in decreasing the PSI prevalence and the days of hospital stay.

Cost-effectiveness of endovascular thrombectomy in patients with low Alberta Stroke Program Early CT Scores (< 6) at presentation

OBJECTIVE

The utility of endovascular thrombectomy (EVT) in patients with acute ischemic stroke, large vessel occlusion (LVO), and low Alberta Stroke Program Early CT Scores (ASPECTS) remains uncertain. The objective of this study was to determine the health outcomes and cost-effectiveness of EVT versus medical management in patients with ASPECTS < 6.

METHODS

A decision-analytical study was performed with Markov modeling to estimate the lifetime quality-adjusted life-years (QALYs) and associated costs of EVT-treated patients compared to medical management. The study was performed over a lifetime horizon with a societal perspective in the US setting.

RESULTS

The incremental cost-effectiveness ratios were $412,411/QALY and $1,022,985/QALY for 55- and 65-year-old groups in the short-term model. EVT was the long-term cost-effective strategy in 96.16% of the iterations and resulted in differences in health benefit of 2.21 QALYs and 0.79 QALYs in the 55- and 65-year-old age groups, respectively, equivalent to 807 days and 288 days in perfect health. EVT remained the more cost-effective strategy when the probability of good outcome with EVT was above 16.8% or as long as the good outcome associated with the procedure was at least 1.6% higher in absolute value than that of medical management. EVT remained cost-effective even when its cost exceeded $100,000 (threshold was $108,036). Although the cost-effectiveness decreased with age, EVT was cost-effective for 75-year-old patients as well.

CONCLUSIONS

This study suggests that EVT is the more cost-effective approach compared to medical management in patients with ASPECTS < 6 in the long term (lifetime horizon), considering the poor outcomes and significant disability associated with nonreperfusion.

Cost-effectiveness analysis in patients with an unruptured cerebral aneurysm treated with observation or surgery

OBJECTIVE

The main goal of preventive treatment of unruptured intracranial aneurysms (UIAs) is to avoid the morbidity and mortality associated with aneurysmal subarachnoid hemorrhage. A comparison between the conservative approach and the surgical approach combining endovascular treatment and microsurgical clipping is currently lacking. This study aimed to conduct an updated evaluation of cost-effectiveness comparing the two approaches in patients with UIA.

METHODS

A decision tree with a Markov model was developed. Quality-adjusted life-years (QALYs) associated with living with UIA before and after treatment were prospectively collected from a cohort of patients with UIA at a tertiary center. Other inputs were obtained from published literature. Using Monte Carlo simulation for patients aged 55, 65, and 75 years, the authors modeled the conservative management in comparison with preventive treatment. Different proportions of endovascular and microsurgical treatment were modeled to reflect existing practice variations between treatment centers. Outcomes were assessed in terms of QALYs. Sensitivity analyses to assess the model's robustness and completed threshold analyses to examine the influence of input parameters were performed.

RESULTS

Preventive treatment of UIAs consistently led to higher utility. Models using a higher proportion of endovascular therapy were more cost-effective. Models with older cohorts were less cost-effective than those with younger cohorts. Treatment was cost-effective (willingness to pay < 100,000 USD/QALY) if the annual rupture risk exceeded a threshold between 0.8% and 1.9% in various models based on the proportion of endovascular treatment and cohort age. A higher proportion of endovascular treatments and younger age lowered this threshold, making the treatment of aneurysms with a lower risk of rupture more cost-effective.

CONCLUSIONS

Preventive treatment of aneurysms led to higher utility compared with conservative management. Models with a higher proportion of endovascular treatment and younger patient age were most cost-effective.

Aging Patient Population With Ruptured Aneurysms: Trend Over 28 Years

BACKGROUND

Given increasing life expectancy in the United States and worldwide, the proportion of elderly patients affected by aneurysmal subarachnoid hemorrhage (aSAH) would be expected to increase.

OBJECTIVE

To determine whether an aging trend exists in the population of aSAH patients presenting to our institution over a 28-yr period.

METHODS

A prospectively maintained database of consecutive patients presenting to our institution with subarachnoid hemorrhage between January 1991 and December 2018 was utilized. The 28-yr period was categorized into 4 successive 7-yr quarter intervals. The age of patients was compared among these intervals, and yearly trends were derived using linear regression.

RESULTS

The cohort consisted of 1671 ruptured aneurysm patients with a mean age of 52.8 yr (standard deviation = 15.0 yr). Over the progressive 7-yr time intervals during the 28-yr period, there was an approximately 4-fold increase in the proportion of patients aged 80 yr or above (P < .001) and an increase in mean patient age from 51.2 to 54.6 yr (P = .002). Independent of this trend but along the same lines, there was a 29% decrease in the proportion of younger patients (<50 yr) from 49% to 35%. On linear regression, there was 1-yr increase in mean patient age per 5 calendar years (P < .001).

CONCLUSION

Analyses of aSAH patients demonstrate an increase in patient age over time with a considerable rise in the proportion of octogenarian patients and a decrease in patients younger than 50 yr. This aging phenomenon presents a challenge to the continued improvement in outcomes of aSAH patients.

Clinical condition of 120 patients alive at 3 years after poor-grade aneurysmal subarachnoid hemorrhage

Background

To study the clinical condition of poor-grade aneurysmal subarachnoid hemorrhage (aSAH) patients alive at 3 years after neurointensive care.

Methods

Of the 769 consecutive aSAH patients from a defined population (2005–2015), 269 (35%) were in poor condition on admission: 145 (54%) with H&H 4 and 124 (46%) with H&H 5. Their clinical lifelines were re-constructed from the Kuopio Intracranial Aneurysm Database and Finnish nationwide registries. Of the 269 patients, 155 (58%) were alive at 14 days, 125 (46%) at 12 months, and 120 (45%) at 3 years.

Results

The 120 H&H 4–5 patients alive at 3 years form the final study population. On admission, 73% had H&H 4 but only 27% H&H 5, 59% intracerebral hematoma (ICH; median 22 cm³), and 26% intraventricular blood clot (IVH). The outcome was favorable (mRS 0–1) in 45% (54 patients: ICH 44%; IVH clot 31%; shunt 46%), moderate (mRS 2–3) in 30% (36 patients: ICH 64%; IVH clot 19%; shunt 42%), and unfavorable (mRS 4–5) in 25% (30 patients: ICH 80%; IVH clot 23%; shunt 50%). A total of 46% carried a ventriculoperitoneal shunt. ICH volume was a significant predictor of mRS at 3 years.

Conclusions

Of poor-grade aSAH patients, 45% were alive at 3 years, even 27% of those extending to pain (H&H 5). Of the survivors, 75% were at least in moderate condition, while only 2.6% ended in hospice care. Consequently, we propose non-selected admission to neurointensive care (1) for a possibility of moderate outcome, and (2), in case of brain death, possibly improved organ donation rates.

The role of imaging in the management of non-traumatic subarachnoid hemorrhage: a practical review

The purpose of this review is to understand the role of imaging in the diagnosis and management of non-traumatic subarachnoid hemorrhage (SAH). SAH is a life-threatening emergency and a relatively common entity, the most common etiology being ruptured aneurysms. Multiple conundrums exist in literature at various steps of its imaging workup: diagnosis, management, and follow-up. We target our review to highlight the most effective practice and suggest efficient workup plans based on literature search, and describe in detail the clinical diagnostic and prognostic scales, role of CT scan, lumbar puncture, and MR, including angiography in the diagnosis and workup of SAH and its complications, and try to simplify the conundrums. Practical knowledge of imaging workup of SAH can help guide correct management of these patients, so as to reduce morbidity and mortality without resource overutilization.

Development and validation of a novel nomogram to predict aneurysm rupture in patients with multiple intracranial aneurysms: a multicentre retrospective study

Background and purpose

Approximately 15%–45% of patients with unruptured intracranial aneurysms have multiple intracranial aneurysms (MIAs). Determining which one is most likely to rupture is extremely important for treatment decision making for MIAs patients. This study aimed to develop and validate a nomogram to evaluate the per-aneurysm rupture risk of MIAs patients.

Methods

A total of 1671 IAs from 700 patients with MIAs were randomly dichotomised into derivation and validation sets. Multivariate logistic regression analysis was used to select predictors and construct a nomogram model for aneurysm rupture risk assessment in the derivation set. The discriminative accuracy, calibration performance and clinical usefulness of this nomogram were assessed. We also developed a multivariate model for a subgroup of 158 subarachnoid haemorrhage (SAH) patients and compared its performance with the nomogram model.

Results

Multivariate analyses identified seven variables that were significantly associated with IA rupture (history of SAH, alcohol consumption, female sex, aspect ratio >1.5, posterior circulation, irregular shape and bifurcation location). The clinical and morphological-based MIAs (CMB-MIAs) nomogram model showed good calibration and discrimination (derivation set: area under the curve (AUC)=0.740 validation set: AUC=0.772). Decision curve analysis demonstrated that the nomogram was clinically useful. Compared with the nomogram model, the AUC of multivariate model developed from SAH patients had lower value of 0.730.

Conclusions

This CMB-MIAs nomogram for MIAs rupture risk is the first to be developed and validated in a large multi-institutional cohort. This nomogram could be used in decision-making and risk stratification in MIAs patients.

Intensive care of traumatic brain injury and aneurysmal subarachnoid hemorrhage in Helsinki during the Covid-19 pandemic

Background

To ensure adequate intensive care unit (ICU) capacity for SARS-CoV-2 patients, elective neurosurgery and neurosurgical ICU capacity were reduced. Further, the Finnish government enforced strict restrictions to reduce the spread. Our objective was to assess changes in ICU admissions and prognosis of traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH) during the Covid-19 pandemic.

Methods

Retrospective review of all consecutive patients with TBI and aneurysmal SAH admitted to the neurosurgical ICU in Helsinki from January to May of 2019 and the same months of 2020. The pre-pandemic time was defined as weeks 1–11, and the pandemic time was defined as weeks 12–22. The number of admissions and standardized mortality rates (SMRs) were compared to assess the effect of the Covid-19 pandemic on these. Standardized mortality rates were adjusted for case mix.

Results

Two hundred twenty-four patients were included (TBI n = 123, SAH n = 101). There were no notable differences in case mix between TBI and SAH patients admitted during the Covid-19 pandemic compared with before the pandemic. No notable difference in TBI or SAH ICU admissions during the pandemic was noted in comparison with early 2020 or 2019. SMRs were no higher during the pandemic than before.

Conclusion

In the area of Helsinki, Finland, there were no changes in the number of ICU admissions or in prognosis of patients with TBI or SAH during the Covid-19 pandemic.

Short- and long-term outcome of patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

To describe short-term and 5-year rates of mortality and poor outcome in patients with spontaneous aneurysmal subarachnoid hemorrhage (aSAH) who received repair treatment.

METHODS

In this prospective observational study, mortality and poor outcome (modified Rankin Scale score 3-6) were analyzed in 311 patients with aSAH at 3 months, 1 year, and 5 years follow-up. Sensitivity analysis was performed according to treatment modality. In-hospital and 5-year complications were analyzed.

RESULTS

Of 476 consecutive patients with spontaneous subarachnoid hemorrhage, 347 patients (72.9%) had aSAH. Of these, 311 (89.6%) were treated (242 endovascular, 69 neurosurgical), with a mean follow-up of 43.4 months (range, 1 to 145). Three-month, 1-year, and 5-year mortality was 18.4%, 22.9%, and 29.0%, and poor outcome was observed in 42.3%, 36.0%, and 36.0%, respectively. Adjusted poor outcome was lower in endovascular than in neurosurgical treatment at 3 months (odds ratio [OR] 0.36 [95% confidence interval [CI] 0.18-0.74]), with an absolute difference of 15.8% (number needed to treat = 6.3), and at 1 year (OR = 0.40 [95% CI 0.20-0.81]), with an absolute difference of 15.9% (number needed to treat = 6.3). Complications did not differ between the 2 procedures. However, mechanical ventilation was less frequent with the endovascular technique (OR 0.67 [95% CI 0.54-0.84]).

CONCLUSIONS

Patients with aSAH treated according to current guidelines had a short-term mortality of 18.4% and 5-year mortality of 29%. The majority (64.0%) of patients remained alive without disabilities at 5-year follow-up. Patients prioritized to endovascular treatment had better outcomes than those referred to neurosurgery because endovascular coiling was not feasible.

Cigarette smoking and risk of intracranial aneurysms in middle-aged women

BACKGROUND AND PURPOSE

We previously reported a single-centre study demonstrating that smoking confers a six-fold increased risk for having an unruptured intracranial aneurysm (UIA) in women aged between 30 and 60 years and this risk was higher if the patient had chronic hypertension. There are no data with greater generalisability evaluating this association. We aimed to validate our previous findings in women from a multicentre study.

METHODS

A multicentre case-control study on women aged between 30 and 60 years, that had magnetic resonance angiography (MRA) during the period 2016-2018. Cases were those with an incidental UIA, and these were matched to controls based on age and ethnicity. A multivariable conditional logistic regression was conducted to evaluate smoking status and hypertension differences between cases and controls.

RESULTS

From 545 eligible patients, 113 aneurysm patients were matched to 113 controls. The most common reason for imaging was due to chronic headaches in 62.5% of cases and 44.3% of controls. A positive smoking history was encountered in 57.5% of cases and in 37.2% of controls. A multivariable analysis demonstrated a significant association between positive smoking history (OR 3.7, 95%CI 1.61 to 8.50), hypertension (OR 3.16, 95% CI 1.17 to 8.52) and both factors combined with a diagnosis of an incidental UIA (OR 6.9, 95% CI 2.49 to 19.24).

CONCLUSIONS

Women aged between 30 and 60 years with a positive smoking history have a four-fold increased risk for having an UIA, and a seven-fold increased risk if they have underlying chronic hypertension. These findings indicate that women aged between 30 and 60 years with a positive smoking history might benefit from a screening recommendation.

Screening for Intracranial Aneurysms in Coarctation of the Aorta: A Decision and Cost-Effectiveness Analysis

BACKGROUND

Patients with coarctation of the aorta have a high prevalence of intracranial aneurysms (IA) and suffer subarachnoid hemorrhage (SAH) at younger ages than the general population. American Heart Association/American College of Cardiology guidelines recommend IA screening, but appropriate age and interval of screening and its effectiveness remain a critical knowledge gap.

METHODS AND RESULTS

To evaluate the benefits and cost-effectiveness of magnetic resonance angiography screening for IA in patients with coarctation of the aorta, we developed and calibrated a Markov model to match published IA prevalence estimates. The primary outcome was the incremental cost-effectiveness ratio. Secondary outcomes included lifetime cumulative incidence of prophylactic IA treatment and mortality and SAH deaths prevented. Using a payer perspective, a lifetime horizon, and a willingness-to-pay of $150 000 per quality-adjusted life-year gained, we applied a 3% annual discounting rate to costs and effects and performed 1-way, 2-way, and probabilistic sensitivity analyses. In a simulated cohort of 10 000 patients, no screening resulted in a 10.1% lifetime incidence of SAH and 183 SAH-related deaths. Screening at ages 10, 20, and 30 years led to 978 prophylactic treatments for unruptured aneurysms, 19 procedure-related deaths, and 65 SAH-related deaths. Screening at ages 10, 20, and 30 years was cost-effective compared with screening at ages 10 and 20 years (incremental cost-effectiveness ratio $106 841/quality-adjusted life-year). Uncertainty in the outcome after aneurysm treatment and quality of life after SAH influenced the preferred screening strategy. In probabilistic sensitivity analysis, screening at ages 10, 20, and 30 years was cost-effective in 41% of simulations and at ages 10 and 20 in 59% of simulations.

CONCLUSIONS

Our model supports the American Heart Association/American College of Cardiology recommendation to screen patients with coarctation of the aorta for IA and suggests screening at ages 10 and 20 or at 10, 20, and 30 years would extend life and be cost-effective.

Neuroinflammation and Microvascular Dysfunction After Experimental Subarachnoid Hemorrhage: Emerging Components of Early Brain Injury Related to Outcome

Aneurysmal subarachnoid hemorrhage has a high mortality rate and, for those who survive this devastating injury, can lead to lifelong impairment. Clinical trials have demonstrated that cerebral vasospasm of larger extraparenchymal vessels is not the sole contributor to neurological outcome. Recently, the focus of intense investigation has turned to mechanisms of early brain injury that may play a larger role in outcome, including neuroinflammation and microvascular dysfunction. Extravasated blood after aneurysm rupture results in a robust inflammatory response characterized by activation of microglia, upregulation of cellular adhesion molecules, recruitment of peripheral immune cells, as well as impaired neurovascular coupling, disruption of the blood-brain barrier, and imbalances in endogenous vasodilators and vasoconstrictors. Each of these phenomena is either directly or indirectly associated with neuronal death and brain injury. Here, we review recent studies investigating these various mechanisms in experimental models of subarachnoid hemorrhage with special emphasis on neuroinflammation and its effect on microvascular dysfunction. We discuss the various therapeutic targets that have risen from these mechanistic studies and suggest the utility of a multi-targeted approach to preventing delayed injury and improving outcome after subarachnoid hemorrhage.

Connective Tissue Abnormalities in Patients with Ruptured Intracranial Aneurysms and No Known Systemic Connective Tissue Disorder

BACKGROUND

Defect in internal elastic lamina, defect in tunica media, and the amount of collagen and elastin play a role in vessel wall weakening leading to aneurysm formation. A similar picture may be found in connective tissue disorders, such as Marfan syndrome, Ehlers-Danlos syndrome (EDS), neurofibromatosis type 1, and Loeys-Dietz syndrome (LDS), where there is a predominant disorder of collagen formation/maturation.

METHODS

Histopathology of skin and the superficial temporal artery (STA) was done. All specimens were obtained during craniotomy for ruptured aneurysm clipping or other indicated procedures (for control subjects). Parameters in skin biopsy seen were epithelial thickness, dermal collagen thickness, and so forth. For the STA, parameters such as intimal thickness, intimal proliferation, thickness of media, and so forth were studied.

RESULTS

Twenty cases and twenty control subjects were studied. The mean age of the study population was 40.5 years. Salient findings on skin biopsy in patients of intracranial aneurysms (IAs) (cases) were haphazard orientation of collagen, inflammation in the subepidermal layer, increased dermal collagen thickness, and reduced and/or fragmented elastic fibers. Prominent findings on vessel wall biopsy were intimal proliferation, reduplication of internal elastic lamina, reduced and/or fragmented elastin, and vacuolation of smooth muscle cells. The average number of aberrations per patient was significantly higher in cases than control subjects.

CONCLUSIONS

The histologic changes seen in skin and the STA in cases of IAs signify a weak connective tissue. Some of these findings are also seen in known connective tissue disorders such as Marfan syndrome, EDS, neurofibromatosis type 1, and LDS. The connective tissue abnormalities found in patients with IAs may be congenital, which gets further accentuated by known risk factors leading to weak vessel wall and subsequent aneurysm formation.

Implications of achieving TICI 2b vs TICI 3 reperfusion in patients with ischemic stroke: a cost-effectiveness analysis

BACKGROUND

The benefit of endovascular thrombectomy (EVT) in stroke patients with large-vessel occlusion (LVO) depends on the degree of recanalization achieved. We aimed to determine the health outcomes and cost implications of achieving TICI 2b vs TICI 3 reperfusion in acute stroke patients with LVO.

METHODS

A decision-analytic study was performed with Markov modeling to estimate the lifetime quality-adjusted life years (QALY) of EVT-treated patients, and costs based on the degree of reperfusion achieved. The study was performed with a societal perspective in the United States' setting. The base case calculations were performed in three age groups: 55-, 65-, and 75-year-old patients.

RESULTS

Within 90 days, achieving TICI 3 resulted in a cost saving of $3676 per patient and health benefit of 11 days in perfect health as compared with TICI 2b. In the long term, for the three age groups, achieving TICI 3 resulted in cost savings of $46,498, $25,832, and $15 719 respectively, and health benefits of 2.14 QALYs, 1.71 QALYs, and 1.23 QALYs. Every 1% increase in TICI 3 in 55-year-old patients nationwide resulted in a cost saving of $3.4 million and a health benefit of 156 QALYs. Among 65-year-old patients, the corresponding cost savings and health benefit were $1.9 million and 125 QALYs.

CONCLUSION

There are substantial cost and health implications in achieving complete vs incomplete reperfusion after EVT. Our study provides a framework to assess the cost-benefit analysis of emerging diagnostic and therapeutic techniques that might improve patient selection, and increase the chances of achieving complete reperfusion.

Clinical Prognosis for SAH Consistent with Redox Imbalance and Lipid Peroxidation

Subarachnoid hemorrhage (SAH) accounts for 3% of all strokes. As more and more data indicates the role of oxidative stress in acute brain damage caused by SAH, an attempt was made to correlate the clinical status of patients with systemic level of antioxidants and lipid peroxidation products. The hemorrhage was diagnosed with brain computed tomography (CT) and aneurysm with angio-CT and angiography, while the vasospasm was monitored with transcranial Doppler. Plasma glutathione peroxidase activity (GSH-Px) and vitamin A, E, and C levels were determined spectrophotometrically and by HPLC, respectively. The levels of polyunsaturated fatty acids (PUFAs) cyclization products were determined by GC–MS, while F₂-isoprostanes and neuroprostanes (NP) were determined by LC–MS. SAH was accompanied by changes in antioxidant capacity in blood plasma, including initially (day 1) an increase in GSH-Px activity, followed by its decrease and a progressive decrease in glutathione (GSH) levels and vitamins A, E, and C. On the other hand, levels of PUFAs cyclization products, F₂-isoprostanes, and neuroprostanes were highest on day 1 (two and eight times higher, respectively) and decreased over time. The levels of 4-HNE (4-hydroxynonenal), 4-ONE (4-oxononenal), and MDA (malondialdehyde) changed similarly. In contrast, the 4-HHE (4-hydroxyhexenal) level reduced after SAH increased significantly after a week. It was found that the deterioration of the overall clinical and neurological condition of SAH patients due to cerebral edema, intracranial hemorrhage, or vasoconstriction corresponded to reduced antioxidant defense and, as a consequence, increased lipid peroxidation and slower observed changes in regression. It can be concluded that monitoring the level of lipid peroxidation products (neuroprostanes, 4-ONE, and MDA) can support the monitoring of the clinical status of patients, especially with regard to the assessment of vasospasm.

Decreased contrast enhancement on high-resolution vessel wall imaging of unruptured intracranial aneurysms in patients taking aspirin

OBJECTIVE

Inflammation plays an integral role in the formation, growth, and progression to rupture of unruptured intracranial aneurysms (UIAs). Animal and human studies have suggested that, due to its antiinflammatory effect, aspirin (ASA) may decrease the risks of growth and rupture of UIAs. High-resolution vessel wall imaging (HR-VWI) has emerged as a noninvasive method to assess vessel wall inflammation and UIA instability. To the authors' knowledge, to date no studies have found a significant correlation between patient use of ASA and contrast enhancement of UIAs on HR-VWI.

METHODS

The University of Iowa HR-VWI Project database was analyzed. This database is a compilation of data on patients with UIAs who prospectively underwent HR-VWI on a 3T Siemens MRI scanner. The presence of aneurysmal wall enhancement was objectively defined using the aneurysm-to-pituitary stalk contrast ratio (CRstalk). This ratio was calculated by measuring the maximal signal intensity in the aneurysmal wall and the pituitary stalk on postcontrast T1-weighted images. Data on aneurysm size, morphology, and location and patient demographics and comorbidities were collected. Use of ASA was defined as daily intake of ≥ 81 mg during the previous 6 months or longer. Univariate and multivariate logistic regression analyses were performed to determine factors independently associated with increased contrast enhancement of UIAs on HR-VWI.

RESULTS

In total, 74 patients harboring 96 UIAs were included in the study. The mean patient age was 64.7 ± 12.4 years, and 60 patients (81%) were women. Multivariate analysis showed that age (OR 1.12, 95% CI 1.05-1.19), aneurysm size ≥ 7 mm (OR 21.3, 95% CI 4.88-92.8), and location in the anterior communicating, posterior communicating, and basilar arteries (OR 10.7, 95% CI 2.45-46.5) were significantly associated with increased wall enhancement on HR-VWI. On the other hand, use of ASA was significantly associated with decreased aneurysmal wall enhancement on HR-VWI (OR 0.22, 95% CI 0.06-0.83, p = 0.026).

CONCLUSIONS

The study results establish a correlation between use of ASA daily for ≥ 6 months and significant decreases in wall enhancement of UIAs on HR-VWI. The findings also demonstrate that detection of wall enhancement using HR-MRI may be a valuable noninvasive method for assessing aneurysmal wall inflammation and UIA instability.

Comparative Effectiveness of Endovascular Thrombectomy in Elderly Stroke Patients

Background and Purpose- Strokes in patients aged ≥80 years are common, and advanced age is associated with relatively poor poststroke functional outcome. The current guidelines do not recommend an upper age limit for endovascular thrombectomy (EVT). The purpose of this study is to evaluate the effectiveness of EVT in acute stroke because of large vessel occlusion for elderly patients >age 80 years. Methods- A Markov decision analytic model was constructed from a societal perspective to evaluate health outcomes in terms of quality-adjusted life years (QALYs) after EVT for acute ischemic stroke because of large vessel occlusion in patients above age 80 years. Age-specific input parameters were obtained from the most recent/comprehensive literature. Good outcome was defined as a modified Rankin Scale score ≤2. Probabilistic, 1-way, and 2-way sensitivity analyses were performed for both healthy patients and patients with disability at baseline. Results- Base case calculation showed in functionally independent patients at baseline, intravenous thrombolysis (IVT) with tPA (tissue-type plasminogen activator) only to be the better strategy with 3.76 QALYs compared to 2.93 QALYs for patients undergoing EVT. The difference in outcome is 0.83 QALY (equivalent to 303 days of life in perfect health). For patients with baseline disability, IVT only yields a utility of 1.92 QALYs and EVT yields a utility of 1.65 QALYs. The difference is 0.27 QALYs (equivalent to 99 days of life in perfect health). Multiple sensitivity analyses showed that the effectiveness of EVT is significantly determined by the morbidity and mortality after both IVT and EVT strategies, respectively. Conclusions- Our study demonstrates the impact of relevant factors on the effectiveness of EVT in patients above 80 years of age. Morbidity and mortality after both IVT and EVT strategies significantly influence the outcomes in both healthy and disabled patients at baseline. Better identification of patients not benefiting from IVT would optimize the selective use of EVT thereby improving its effectiveness.

Using Cerebral Metabolites to Guide Precision Medicine for Subarachnoid Hemorrhage: Lactate and Pyruvate

Subarachnoid hemorrhage (SAH) is one of the deadliest types of strokes with high rates of morbidity and permanent injury. Fluctuations in the levels of cerebral metabolites following SAH can be indicators of brain injury severity. Specifically, the changes in the levels of key metabolites involved in cellular metabolism, lactate and pyruvate, can be used as a biomarker for patient prognosis and tailor treatment to an individual’s needs. Here, clinical research is reviewed on the usefulness of cerebral lactate and pyruvate measurements as a predictive tool for SAH outcomes and their potential to guide a precision medicine approach to treatment.

Impact of Acute Cardiac Complications After Subarachnoid Hemorrhage on Long-Term Mortality and Cardiovascular Events

Background

Cardiac complications frequently occur after subarachnoid hemorrhage (SAH) and are associated with an increased risk of neurological complications and poor outcomes. The aim of this study was to evaluate the impact of acute cardiac complications after SAH on long-term mortality and cardiovascular events.

Methods

All patients admitted to our Neuro intensive care unit with verified SAH from January 2010 to April 2015, and electrocardiogram, echocardiogram, and troponin T or NTproBNP data obtained within 72 h of admission were included in the study. Mortality data were obtained from the Swedish population register. Data regarding cause of death and hospitalization for cardiovascular events were obtained from the Swedish Board of Health and Welfare.

Results

A total of 455 patients were included in the study analysis. There were 102 deaths during the study period. Cardiac troponin release (HR 1.08, CI 1.02–1.15 per 100 ng/l, p = 0.019), NTproBNP (HR 1.05, CI 1.01–1.09 per 1000 ng/l, p = 0.018), and ST-T abnormalities (HR 1.53, CI 1.02–2.29, p = 0.040) were independently associated with an increased risk of death. However, these associations were significant only during the first 3 months after the hemorrhage. Cardiac events were observed in 25 patients, and cerebrovascular events were observed in 62 patients during the study period. ST-T abnormalities were independently associated with an increased risk of cardiac events (HR 5.52, CI 2.07–14.7, p < 0.001), and stress cardiomyopathy was independently associated with an increased risk of cerebrovascular events (HR 3.65, CI 1.55–8.58, p = 0.003).

Conclusion

Cardiac complications after SAH are associated with an increased risk of short-term death. Patients with electrocardiogram abnormalities and stress cardiomyopathy need appropriate follow-up for the identification of cardiac disease or risk factors for cardiovascular disease.

Electronic supplementary material

The online version of this article (10.1007/s12028-018-0558-0) contains supplementary material, which is available to authorized users.

Management of Tiny Unruptured Intracranial Aneurysms: A Comparative Effectiveness Analysis

Importance

Unruptured intracranial aneurysms (UIAs) are relatively common in the general population and are being increasingly diagnosed; a significant proportion are tiny (≤3 mm) aneurysms. There is significant heterogeneity in practice and lack of clear guidelines on the management of incidental, tiny UIAs. It is important to quantify the implications of different management strategies in terms of health benefits to patients.

Objective

To evaluate the effectiveness of routine treatment (aneurysm coiling) vs 3 strategies for imaging surveillance compared with no preventive treatment or routine follow-up of tiny UIAs.

Design, Setting, and Participants

A decision-analytic model-based comparative effectiveness analysis was conducted from May 1 to June 30, 2017, using inputs from the medical literature. PubMed searches were performed to identify relevant literature for all key model inputs, each of which was derived from the clinical study with the most robust data and greatest applicability. Analysis included 10 000 iterations simulating adult patients with incidental detections of UIAs 3 mm or smaller and no history of subarachnoid hemorrhage.

Interventions

The following 5 management strategies for tiny UIAs were evaluated: annual magnetic resonance angiography (MRA) screening, biennial MRA screening, MRA screening every 5 years, aneurysm coiling and follow-up, and no treatment or preventive follow-up.

Main Outcomes and Measures

A Markov decision model for lifetime rupture was constructed from a societal perspective per 10 000 patients with incidental, tiny UIAs. Outcomes were assessed in terms of quality-adjusted life-years. Probabilistic, 1-way, and 2-way sensitivity analyses were performed.

Results

In this analysis of 10 000 iterations simulating adult patients with a mean age of 50 years, the base-case calculation shows that the management strategy of no treatment or preventive follow-up has the highest health benefit (mean [SD] quality-adjusted life-years, 19.40 [0.31]). Among the management strategies that incorporate follow-up imaging, MRA every 5 years is the best strategy with the next highest effectiveness (mean [SD] quality-adjusted life-years, 18.05 [0.62]). The conclusion remains robust in probabilistic and 1-way sensitivity analyses. No routine follow-up remains the optimal strategy when the annual growth rate and risk of rupture of growing aneurysms are varied. When the annual risk of rupture of nongrowing UIAs is less than 1.7% (0.23% in base case scenario), no follow-up is the optimal strategy. If annual risk of rupture is more than 1.7%, coiling should be performed directly.

Conclusions and Relevance

Given the current literature, no preventive treatment or imaging follow-up is the most effective strategy in patients with aneurysms that are 3 mm or smaller, resulting in better health outcomes. More aggressive imaging surveillance for aneurysm growth or preventive treatment should be reserved for patients with a high risk of rupture. Given these findings, it is important to critically evaluate the appropriateness of current clinical practices, and potentially determine specific guidelines to reflect the most effective management strategy for patients with incidental, tiny UIAs.

Cost-Effectiveness of Computed Tomography Angiography in Management of Tiny Unruptured Intracranial Aneurysms in the United States

Background and Purpose—

Our study aims to evaluate the cost-effectiveness of computed tomography angiography (CTA) for surveillance of tiny unruptured intracranial aneurysms and the impact of CTA radiation-induced brain tumor on the overall effectiveness of CTA.

Methods—

A Markov decision model was constructed from a societal perspective starting with patients 30-, 40-, or 50-year-old, with incidental detection of unruptured intracranial aneurysm ≤3 mm and no prior history of subarachnoid hemorrhage. Five different management strategies were assessed (1) annual CTA surveillance, (2) biennial CTA, (3) CTA follow-up every 5 years, (4) coiling and subsequent magnetic resonance imaging follow-up, and (5) annual CTA surveillance for the first 2 years, followed by every 5-year CTA follow-up. Probabilistic, 1-way, and 2-way sensitivity analyses were performed.

Results—

The base case calculation shows every 5-year CTA follow-up to be the most cost-effective strategy, and the conclusion remains robust in probabilistic sensitivity analysis. It remains the dominant strategy when the annual rupture risk of nongrowing unruptured intracranial aneurysms is smaller than 2.66% or the rupture risk in growing aneurysms is <57.4%. The radiation-induced brain cancer risk is relatively low, and sensitivity analysis shows that the radiation-induced cancer risk does not influence the conclusions unless the risk exceeds 663-fold of the base case values.

Conclusions—

Given the current literature, every 5-year CTA imaging follow-up is the cost-effective strategy in patients with aneurysms ≤3 mm, resulting in better health outcomes and lower healthcare spending. Patients with aneurysms at high risk of rupture might need more aggressive management.