Aneurysmatic subarachnoidal haemorrhage: Incidence and location of small ruptured cerebral aneurysms – a retrospective population-based study

Development of a predictive nomogram for 28-day mortality risk in non-traumatic or post-traumatic subarachnoid hemorrhage patients

OBJECTIVE

Subarachnoid hemorrhage (SAH) is associated with high rates of mortality and permanent disability. At present, there are few definite clinical tools to predict prognosis in SAH patients. The current study aims to develop and assess a predictive nomogram model for estimating the 28-day mortality risk in both non-traumatic or post-traumatic SAH patients.

METHODS

The MIMIC-III database was searched to select patients with SAH based on ICD-9 codes. Patients were separated into non-traumatic and post-traumatic SAH groups. Using LASSO regression analysis, we identified independent risk factors associated with 28-day mortality and incorporated them into nomogram models. The performance of each nomogram was assessed by calculating various metrics, including the area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).

RESULTS

The study included 999 patients with SAH, with 631 in the non-traumatic group and 368 in the post-traumatic group. Logistic regression analysis revealed critical independent risk factors for 28-day mortality in non-traumatic SAH patients, including gender, age, glucose, platelet, sodium, BUN, WBC, PTT, urine output, SpO2, and heart rate and age, glucose, PTT, urine output, and body temperature for post-traumatic SAH patients. The prognostic nomograms outperformed the commonly used SAPSII and APSIII systems, as evidenced by superior AUC, NRI, IDI, and DCA results.

CONCLUSION

The study identified independent risk factors associated with the 28-day mortality risk and developed predictive nomogram models for both non-traumatic and post-traumatic SAH patients. The nomogram holds promise in guiding prognosis improvement strategies for patients with SAH.

Trend of cerebral aneurysms over the past two centuries: need for early screening

OBJECTIVE

Cerebral aneurysms (CAs) are linked to variations in the cerebral basal arterial network (CBAN). This study aimed to find the optimal age for screening to detect brain arterial variations and predict aneurysms before rupture.

DESIGN

An observational, quantitative and retrospective research.

SETTING

The study analysed 1127 cases of CAs published from 1761 to 1938. Additionally, CT angiography images of 173-patients at the Royal Adelaide Hospital (RAH), South Australia between 2011 and 2019 were examined for the presence and the location of aneurysms in CBAN.

PARTICIPANTS

The data were collected from patients at RAH and 407 published sources, including males and females across the entire age range, up to 100 years old.

OUTCOME MEASURES AND RESULTS

Data, CAs cases, from 1761 to 1938 included (526 males, 573 females and 28 unknown sexes). The age of these patients varied from 18 months to 89 years (mean age=42, SD=18). Approximately 11.5% of the CAs occurred in patients aged <20 years. Among the 1078 aneurysms whose location was reported, 76% were located in the internal carotid (IC), middle cerebral (MC) and anterior communicating artery complex (AcomAC) regions, while the remaining 24% were in the vertebrobasilar region. Among 173 patients from RAH aged between 18 and 100 years (male=83 and female=90, mean age=60, SD=16), 94% of the CAs were found in the IC, MC and AcomAC regions. The pattern of aneurysm occurrence, as indicated by values at the 25th, 50th and 75th percentiles, along with the minimum and maximum patient ages, has remained consistent from 1761 to 2019.

CONCLUSION

The distribution pattern of CAs in relation to sex, age and locations in the CBAN, remained steady over the last 260 years resulting in risk of strokes early in life. Therefore, early screening for CBAN segment variations is advised for stroke prevention if possible.

Will improved neuroradiology facilities debunk the reported rarity of intracranial aneurysms in Sub-Saharan Africa?

Background:

Intracranial aneurysms (IAN) are rare in the Sub-Saharan Africa unlike other parts of the world. The debate is whether the low frequency might be apparent because of the scarcity of advanced neuroimaging services, or real. This study investigated if improved imaging facilities would debunk the rarity of IAN in our subregion.

Methods:

This is a retrospective cohort study of prospectively recorded data of patients with subarachnoid hemorrhage (SAH) and IAN managed over 19 years (2003–2021), at the study center with a catchment population of over 47 million. The center witnessed progressive improvements in neuroimaging facilities: 2-Slice, 8-slice, and 64-slice computed tomography (CT) and 0.35T, 1.5T magnetic resonance imaging (MRI) during the period.

Results:

There were 241 cases of SAH, but only 166 aneurysms were confirmed in 158 patients. Between 2003 and 2008, only 27 IAN patients (4.5 IAN/year) were diagnosed. After introduction of CT angiography/magnetic resonance angiography MRA using 8-slice CT/0.35T magnetic resonance imaging (MRI), between 2009 and 2014, the frequency of IAN increased to 8/year. Between 2015 and 2018 after installation of a 64-slice CT in 2014, the IAN remained the same (8/year). MRI 1.5T was added in 2018, the frequency doubled to 17 cases/year. The females were more (67.7%), the mean age was 46.3 years, but peak incidence was the sixth decade. Internal carotid artery aneurysms including posterior communicating artery were the most common (43%) followed by ACA with anterior communicating artery (24%) and middle cerebral artery (20%). Multiple aneurysms were seen in ten patients.

Conclusion:

Improved neuroimaging between 2003 and 2021 did not debunk the rarity of IAN in our region.

Shedding the Light on the Natural History of Intracranial Aneurysms: An Updated Overview

The exact molecular pathways underlying the multifactorial natural history of intracranial aneurysms (IAs) are still largely unknown, to the point that their understanding represents an imperative challenge in neurovascular research. Wall shear stress (WSS) promotes the genesis of IAs through an endothelial dysfunction causing an inflammatory cascade, vessel remodeling, phenotypic switching of the smooth muscle cells, and myointimal hyperplasia. Aneurysm growth is supported by endothelial oxidative stress and inflammatory mediators, whereas low and high WSS determine the rupture in sidewall and endwall IAs, respectively. Angioarchitecture, age older than 60 years, female gender, hypertension, cigarette smoking, alcohol abuse, and hypercholesterolemia also contribute to growth and rupture. The improvements of aneurysm wall imaging techniques and the implementation of target therapies targeted against inflammatory cascade may contribute to significantly modify the natural history of IAs. This narrative review strives to summarize the recent advances in the comprehension of the mechanisms underlying the genesis, growth, and rupture of IAs.

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year, Hospital-Based Study

BACKGROUND

The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear.

OBJECTIVE

To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data.

METHODS

A database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference.

RESULTS

Altogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend.

CONCLUSION

We found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.

Incidence and Case-Fatality of Aneurysmal Subarachnoid Hemorrhage in Australia, 2008-2018

BACKGROUND

Contemporary aneurysmal subarachnoid hemorrhage (aSAH) and case-fatality studies have suggested a diminishing worldwide incidence. The purpose of this study was to examine whether such epidemiologic trends occur in Australia.

METHODS

This retrospective cross-sectional study was based on data retrieved from the Nationwide Hospital Morbidity Database for all aSAH cases across hospital networks in Australia between 2008 and 2018. Information on patient characteristics, aneurysm location, procedures performed, and discharge disposition were extracted. We estimated the crude and age-adjusted incidences, trends of aSAH, and case fatality rate over time. Putative risk factors were investigated with univariate and multivariate logistic regression analysis to identify independent predictors of unfavorable discharge outcome (death and dependency).

RESULTS

A total of 12,915 acute hospital admissions with aSAH were identified. Annual aSAH rate remained stable (mean 5.5, range 5.3-6.0 cases per 100,000 person-years) with no decline. The overall aSAH-associated 30-day case-fatality rate was 26.7% of admissions and declined by approximately 0.7% annually (P < 0.0001). Age-adjusted incidence increased with advancing age at increments of 1.3 cases per 100,000 person-years for each 5 years after the age of 40 years. Endovascular therapy accounted for 63.1% of the overall treatment strategy. Logistic regression demonstrated older age (P < 0.0001), presence of intracerebral or intraventricular hemorrhage (P < 0.0001), and hypertension (P = 0.0007) were significant predictors of unfavorable outcome.

CONCLUSIONS

A decline in 30-day case-fatality rate but not aSAH incidence from 2008 to 2018 was observed.

Size of ruptured intracranial aneurysms: a systematic review and meta-analysis

BACKGROUND

There is wide variation in the reported size of ruptured intracranial aneurysms and methods of size estimation. There is widespread belief that small aneurysms < 7 mm do not rupture. Therefore, we performed a systematic review and meta-analysis of the literature to determine the size of ruptured aneurysms according to aneurysm locations and methods of size estimation.

METHODS

We searched PubMed, Cochrane, CINAHL, and EMBASE databases using a combination of Medical Subject Headings (MeSH) terms. We included articles that reported mean aneurysm size in consecutive series of ruptured intracranial. We excluded studies limited to a specific aneurysm location or type. The random-effects model was used to calculate overall mean size and location-specific mean size. We performed meta-regression to explain observed heterogeneity and variation in reported size.

RESULTS

The systematic review included 36 studies and 12,609 ruptured intracranial aneurysms. Overall mean aneurysm size was 7.0 mm (95% confidence interval [CI 6.2-7.4]). Pooled mean size varied with location. Overall mean size of 2145 ruptured anterior circulation aneurysms was 6.0 mm (95% CI 5.6-6.4, residual I² = 86%). Overall mean size of 743 ruptured posterior circulation aneurysms was 6.2 mm (95% CI 5.3-7.0, residual I² = 93%). Meta-regression identified aneurysm location and definition of size (i.e., maximum dimension vs. aneurysm height) as significant determinants of aneurysm size reported in the studies.

CONCLUSIONS

The mean size of ruptured aneurysms in most studies was approximately 7 mm. The general wisdom that aneurysms of this size do not rupture is incorrect. Location and size definition were significant determinants of aneurysm size.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Fabrication of cerebral aneurysm simulator with a desktop 3D printer

Now, more and more patients are suffering cerebral aneurysm. However, long training time limits the rapid growth of cerebrovascular neurosurgeons. Here we developed a novel cerebral aneurysm simulator which can be better represented the dynamic bulging process of cerebral aneurysm The proposed simulator features the integration of a hollow elastic vascular model, a skull model and a brain model, which can be affordably fabricated at the clinic (Fab@Clinic), under $25.00 each with the help of a low-cost desktop 3D printer. Moreover, the clinical blood flow and pulsation pressure similar to the human can be well simulated, which can be used to train the neurosurgical residents how to clip aneurysms more effectively.

Expanding the use of flow diverters beyond their initial indication: treatment of small unruptured aneurysms

Background

Experience with the endovascular treatment of unruptured small intracranial aneurysms by flow diverter devices is still limited.

Objective

To assess the safety and efficacy of the SILK flow diverter (SFD) in the treatment of small unruptured cerebral aneurysms (<10 mm).

Methods

We performed a retrospective review of a prospectively maintained database of patients treated with a SFD between July 2008 and December 2013 at 4 institutions in Spain to identify all patients with small unruptured aneurysms (<10 mm). Data for patient demographics, aneurysm characteristics, and technical procedures were analyzed. Angiographic and clinical findings were recorded during the procedure and at 6- and 12-month follow-ups.

Results

A total of 109 small aneurysms were treated with a SFD in 104 patients (78 women; 26 men; mean, median, and range of age: 55.2, 57.1, and 19–80 years, respectively). A total of 60 patients were asymptomatic (57.7%). All except 7 aneurysms (6.4%) arose from the anterior circulation. The mean size of the aneurysms was 4.7±1.9 mm. At 6 months, the neuromorbidity and neuromortality rates were 2.9% and 0.9%, respectively. Imaging at the 12-month follow-up showed complete occlusion, neck remnants, and residual aneurysm in 88.5% (69/78), 7.7% (6/78), and 3.3% (3/78) of cases, respectively. No delayed hemorrhage occurred.

Conclusions

The findings suggest that the indications for SFD can be safely extended to small intracranial aneurysms.

Digital subtraction angiography findings and population demographics of patients with subarachnoidal haemorrhage and subsequent causative aneurysms at Universitas Academic Hospital, Bloemfontein

Background: Subarachnoid haemorrhage (SAH) secondary to aneurysmal rupture may be associated with serious neurological sequelae or even mortality. According to international literature, only aneurysms >7 mm or aneurysms in the posterior circulation require treatment. Retrospective single-centre studies have, however, disputed this after demonstrating that the average size of ruptured aneurysms are <7 mm. More recent guidelines place less emphasis on size and more on associated risk factors.Objectives: The aim of this investigation was to assess the aneurysm characteristics and demographics of patients who presented to our institution with SAH secondary to an aneurysm detected at digital subtraction angiography (DSA).Method: A retrospective descriptive study was conducted. Patients who presented with SAH over a 6-year period, from 2008 to 2013, were included. The average size of the intracranial aneurysms at the time of rupture was analysed. Data about aneurysm characteristics and patient demographics were obtained from patient files. Data were analysed by the researchers with assistance from the Department of Biostatistics.Results: In total, 161 of 374 patients who underwent DSA had ruptured aneurysms. Most patients were women with ages ranging from 18 to 73 years (mean 45 years). The mean size of aneurysms were 5.8 mm (range 1.2 mm – 20 mm), with 74.5% of aneurysms <7 mm. Most aneurysms were noted involving the anterior circulation (72%), with the majority arising from the anterior communicating artery (36.7%).Conclusion: We found that aneurysms rupture at sizes <7 mm and are commonly located in the anterior circulation. Our findings emphasise the importance of conducting institutional reviews to consider adapting international treatment guidelines for the local South African situation.

Cerebral aneurysm treatment: modern neurovascular techniques

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years.

Epidemiological investigation of 264 sporadic cases of ruptured cerebral aneurysm at a single institution in southwest China

BACKGROUND

The purpose of this study was to investigate the epidemiology of sporadic ruptured cerebral aneurysm in the Chinese population.

METHODS

We retrospectively analyzed the medical records of 264 consecutive Chinese patients admitted to the Affiliated Hospital of Zunyi Medical University of Guizhou Province in Southwest China between December 2012 and March 2015 for spontaneous subarachnoid hemorrhage due to a ruptured cerebral artery aneurysm.

RESULTS

The study population comprised 171 females and 93 males with a median age of 50 (range 5-76) years. The female to male ratio was 1.84:1. For both males and females, aneurysm rupture was most common in the 40-49-year age group (34.5%). Most of the ruptured aneurysms were in the size range of 2-5 mm (47.2%), followed by 5-10 mm (43.8%). Ruptured aneurysms occurred most often in the posterior communicating artery (36.6%) or the anterior communicating artery (25.7%). There were more cases of anterior communicating artery aneurysm on the left side (53 [Left side]/16 [Right side]=3.31, P>0.001) and slightly more cases of posterior communicating artery aneurysm on the right side (54 [Right side]/44[Left side]=1.23, P<0.05).

CONCLUSION

This study provides valuable information on the epidemiology of ruptured cerebral aneurysm in the Chinese population.

An analysis of 1256 cases of sporadic ruptured cerebral aneurysm in a single Chinese institution

BACKGROUND

To review the epidemiology of sporadic ruptured cerebral aneurysm.

METHODS

This is a retrospective study of consecutive 1256 Chinese patients between January 2006 and January 2013, who were admitted to the Second Hospital of Hebei Medical University, China, for spontaneous subarachnoid hemorrhage due to a rupture of cerebral artery aneurysm. In 288 males and 478 females, the size of aneurysms was measured by a neuroradiologist on DSA. In 123 males and 184 females, the size of the ruptured aneurysms was not measured. The remaining patients, with 61 males and 122 females, had multiple aneurysms, and the medical record could not reliably determine the specific aneurysm responsible for the rupture.

RESULTS

In total there were 784 females and 472 males with a female/male ratio of 1.66. The female/male ratio was down to 0.50 for patients younger than 35 yrs. For both males and females, aneurysm rupture was most common during the age of 50-59 yrs. Ruptured aneurysms were mostly of 2 mm-5 mm in size (47.1%), followed by 5 mm-10 mm (39.7%). Ruptured single cerebral aneurysm occurred in anterior circulation in 95.0% of the cases, with 5.0% occurred in posterior circulation. Ruptured aneurysm most commonly occurred at posterior communicating artery (34.9%) and anterior communicating artery (29.5%). 183 cases (14.6%) had multiple aneurysms.

CONCLUSIONS

With younger patients, there is a male predominance in our series. Ninety percent of patients have ruptured aneurysms less than 10 mm in size.

Immediate and follow-up results for 44 consecutive cases of small (<10 mm) internal carotid artery aneurysms treated with the pipeline embolization device

Background:

The pipeline embolization device (PED) provides effective, durable and safe endovascular reconstruction of large and giant intracranial aneurysms. However, 80% of all cerebral aneurysms found in the general population are less than 10 mm in size. Treatment of small aneurysms (<10 mm) with flow diverters may be advantageous over endosaccular modalities that carry risks of procedural rupture during aneurysm access or coil placement.

Methods:

We retrospectively reviewed a prospective, single-center aneurysm database to identify all patients with small (<10 mm) internal carotid artery (ICA) aneurysms who underwent endovascular treatment using the PED. Patient demographics, aneurysm characteristics, procedural details, complications, and technical and clinical outcomes were analyzed.

Results:

Forty-four cases were performed in 41 patients (age range 31-78 years). PED was successfully implanted in 42 cases. A single PED was used in 37/42 (88%) cases. Mean postprocedure hospital stay was 1.7 ± 0.3 days and 98% of patients were discharged home. Major complication occurred in one patient (2.3%), who died of early subarachnoid hemorrhage. Transient neurological deficit, delayed intracerebral hemorrhage (asymptomatic), and delayed groin infection occurred in one patient each. Follow-up rate was 91.8% (45 aneurysms in 35 patients) with a mean follow-up of 4.0 ± 1.9 months. By 6 months post-PED implantation, angiographic success (complete or near complete aneurysm occlusion) was observed in 80%. Mild (<50%), asymptomatic, nonflow limiting in-stent stenosis was observed in 5.4% (2/37 cases). All the 35 patients with follow-up remained at preprocedure neurological baseline.

Conclusion:

Small (<10 mm) ICA aneurysm treatment with PED implantation is safe and carries a high rate of early angiographic success.