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Background: Improved endovascular methods make it possible to treat complex ruptured aneurysms, but surgery is still needed in certain cases. We evaluated the effects on the clinical results of the changes in aneurysm treatment., Methods: The study cohort was 837 patients with spontaneous subarachnoid hemorrhage (SAH) and one or multiple aneurysms, admitted to Dept of Neurosurgery, Uppsala University Hospital from 2012 to 2021. Demography, location and treatment of aneurysms, neurologic condition at admission and discharge, mortality and last tier treatment of high intracranial pressure (ICP) was evaluated. Functional outcome was measured using the Extended Glasgow Outcome Scale (GOSE) Data concerning national incidences of stroke diseases was collected from open Swedish databases., Results: Endovascular methods were used in 666 cases (79.6%). In 111 (13.3%) with stents. Surgery was performed in 115 cases (13.7%) and 56 patients (6.7%) had no aneurysm treatment. The indications for surgery were a hematoma (51 cases, 44.3%), endovascular treatment not considered safe (47 cases, 40.9%), or had been attempted without success (13 cases, 11.3%). Treatment with stent devices increased, and with surgery decreased over time. There was a trend in decrease in hemicraniectomias over time. Both the patient group admitted awake (n = 681) and unconscious (n = 156) improved significantly in consciousness between admission and discharge. Favorable outcome (GOSE 5-8) was seen in 69% for patients admitted in Hunt & Hess I-II and 25% for Hunt & Hess III-V. Mortality at one year was 10.9% and 42.7% for those admitted awake and unconscious, respectively.The number of cases decreased during the study period, which was in line with Swedish national data., Conclusions: The incidence of patients with SAH gradually decreased in our material, in line with national data. The treatment policy in our unit has been shifting to more use of endovascular methods. During the study period the use of hemicraniectomies decreased., (© 2024. The Author(s).)

Objective: Treatment modality for ruptured and unruptured intracranial aneurysms has shifted during the last two decades from microsurgical treatment towards endovascular treatment. We present how this transition happened in a large European neurovascular center., Methods: We conducted a retrospective observational study consecutive patients treated for an unruptured or ruptured intracranial aneurysm at Helsinki University Hospital during 2012-2022. We used Poisson regression analysis to report age-adjusted treatment trends by aneurysm location and rupture status., Results: A total of 2491 patients with intracranial aneurysms were treated (44% ruptured, 56% unruptured): 1421 (57%) surgically and 1070 (43%) endovascularly. A general trend towards fewer treated aneurysms was noted. The proportion of patients treated surgically decreased from 90% in 2012 to 20% in 2022. The age-adjusted decrease of surgical versus endovascular treatment was 6.9%/year for all aneurysms, 6.8% for ruptured aneurysms, and 6.8% for unruptured aneurysms. The decrease of surgical treatment was most evident in unruptured vertebrobasilar aneurysms (10.8%/year), unruptured communicating artery aneurysms (10.1%/year), ruptured communicating artery aneurysms (10.0%/year), and ruptured internal carotid aneurysms (9.0%/year). There was no change in treatment modality for middle cerebral artery aneurysms, of which 85% were still surgically treated in 2022. A trend towards an increasing size for treated ruptured aneurysms was found (p = 0.033)., Conclusion: A significant shift of the treatment modality from surgical to endovascular treatment occurred for all aneurysm locations except for middle cerebral artery aneurysms. Whether this shift has affected long-term safety and patient outcomes should be assessed in the future., (© 2024. The Author(s).)

Background: Presently, a consistent strategy for determining the stability of unruptured intracranial aneurysms (UIAs) in elderly patients is lacking, primarily due to the unique characteristics of this demographic. Our objective was to assess the risk factors contributing to aneurysm instability (growth or rupture) within the elderly population., Methods: In this study, we compiled data from follow-up patients with UIAs spanning from November 2016 to August 2021. We specifically focused on patients aged ≥ 60 years. Clinical histories were gathered, and morphological parameters of aneurysms were measured. The growth of aneurysms was determined using the computer-assisted semi-automated measurement (CASAM). Growth and rupture rates of UIAs were calculated, and both univariate and multivariate Cox regression analyses were conducted. Additionally, Kaplan-Meier survival curves were plotted., Results: A total of 184 patients with 210 aneurysms were enrolled in the study. The follow-up period encompasses 506.6 aneurysm-years and 401.4 patient-years. Among all the aneurysms, 23 aneurysms exhibited growth, with an annual aneurysm growth rate of 11.0%, and 1 (4.5%) experienced rupture, resulting in an annual aneurysm rupture rate of 0.21%. Multivariate Cox analysis identified poorly controlled hypertension (P = 0.011) and high-risk aneurysms (including anterior cerebral artery (ACA), anterior communicating artery (AcoA), posterior communicating artery aneurysm (PcoA), posterior circulation (PC) > 4 mm or distal internal carotid artery (ICAd), middle cerebral artery (MCA), and PC > 7 mm) (P = 0.006) as independent risk factors for the development of unstable aneurysms., Conclusions: In the elderly, poorly controlled hypertension and high-risk aneurysms emerge as significant risk factors for aneurysm instability. This underscores the importance of rigorous surveillance or timely intervention in patients presenting with these risk factors., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: It is estimated that significant (3.2%) of population carries intracranial aneurysm (IA). An increasing number of imaging studies have caused that the chance of finding an incidental aneurysm is becoming more common. Since IA rupture causes subarachnoidal hemorrhage (SAH) and have significant mortality and morbidity prophylactic treatment should be considered when IA is detected. The benefit and risk of treatment of IA is based on epidemiological estimate which takes account patient and aneurysm characteristics. However we know that aneurysm rupture is biological process where inflammation of aneurysm wall is actively leading to degeneration of aneurysm wall and finally weakens it until it bursts. Until now, there have not been imaging method to detect inflammatory process of aneurysm wall METHODS: We created targeting immunoliposome for use in the imaging of aneurysm. Immunoliposome comprises antibodies against at least one vascular inflammatory marker associated with aneurysm inflammation and a label and/or a contrast agent., Results: Histological analysis of IAs where immunoliposome comprises antibodies against vascular inflammation with a label shows promising results for selectively detecting aneurysms inflammation. In magnetic resonance imaging (MRI) we were able to detect immunoliposomes carrying gadolinium., Conclusion: Our work opens a new avenue for using contrast labeled immunoliposomes for detecting rupture-prone aneurysms. Immunoliposomes can cary gadolinium and selectively bind to inflammatory section of aneurysm that can be detected with MRI. Further research is needed to develop immunoliposomes to be used with MRI in humans to target treatment to those patients who benefit from it the most., (© 2023. The Author(s).)

Although hypertension is a known risk factor for intracranial aneurysm rupture, the benefit of the management of blood pressure in reducing the rupture risk of intracranial aneurysms remains largely unknown, especially for regular blood pressure monitoring. We conducted a retrospective analysis of a prospectively maintained database of 3965 patients with saccular intracranial aneurysms from 20 medical centers in China. The patients were divided into the non-hypertensive group and hypertensive group. Propensity score matching was applied to identify a cohort of patients with similar baseline characteristics. Univariable and multivariable logistic regression analyses were performed to determine the association between intracranial aneurysm rupture and the management of blood pressure. After matching, hypertension was significantly associated with an increased rupture risk of intracranial aneurysms (OR = 2.559, 95%CI = 2.161-3.030, P = 0.000). For the management of blood pressure, controlled hypertension (OR = 1.803, 95%CI = 1.409-2.307, P = 0.000), uncontrolled hypertension (OR = 2.178, 95%CI = 1.756-2.700, P = 0.000), and hypertension without regular blood pressure monitoring (OR = 5.000, 95%CI = 3.823-6.540, P = 0.000) were all significantly associated with a higher rupture risk compared with the absence of hypertension. Moreover, hypertension without regular blood pressure monitoring was associated with a higher rupture risk compared with either controlled hypertension (OR = 3.807, 95%CI = 2.687-5.395, P = 0.000) or hypertension with regular blood pressure monitoring (including controlled and uncontrolled hypertension) (OR = 2.893, 95%CI = 2.319-3.609, P = 0.000). The absence of regular blood pressure monitoring was significantly associated with an increased risk of intracranial aneurysm rupture, emphasizing the importance of implementation of regular blood pressure monitoring in hypertensive patients with intracranial aneurysms., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Intracranial aneurysm (IA) rupture in pediatric patients is a rare but fatal condition. Although risk factors for aneurysm rupture in adults have been well documented, they remain unknown in pediatric patients., Methods: Data for 94 pediatric patients with IAs were retrospectively analyzed. The patients were divided into ruptured and unruptured groups. Risk factors for aneurysm rupture were analyzed through univariable and multiple logistic regression analyses. Typical patients with risk factors were described., Results: Univariable analyses showed that the unruptured group had significantly higher percentages of giant aneurysms (43.2% vs 12.3%, P = 0.002), wide-neck aneurysms (67.6% vs 29.8%, P = 0.001), and aneurysms located in the internal carotid artery (40.5% vs 3.5%, P < 0.001), while the ruptured group had significantly higher percentages of patients younger than 5 years old (28.1% vs 5.4%, P = 0.013) and aneurysms located in the anterior cerebral artery (24.6% vs 5.4%, P = 0.032), posterior cerebral artery (14.0% vs 0%, P = 0.045), and distal arterial region (DAR) (46.8% vs 27.0%, P < 0.001). Multiple logistic regression analysis confirmed that age 0-5 years (OR = 6.844, P = 0.042) and IAs located in the DAR (OR = 4.162, P = 0.029) were independently related to an increased risk of rupture. Wide-necked aneurysms (OR = 0.235, P = 0.047) were independently associated with a lower risk of rupture., Conclusions: Among pediatric patients, age younger than 5 years and lesions located in the DAR are independent risk factors for IA rupture, while an IA with a wide neck acts as a protective factor., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: The incidence of aneurysms is steadily increasing in older patients due to the aging population. This study compared radiological parameters as well as clinical outcomes between patients younger than 65 years and those over 65 years of age, with special respect to individual treatment options., Methods: Retrospective data were obtained for patients with cerebral aneurysms at a single academic institution within a 7-year period. Data reviewed included admission protocols, patient charts, operating reports as well as outpatient clinic charts. Aneurysmal characteristics as well as surgical outcome were compared between older patients, defined as patients older than 65 years of age, and a control group of patients younger than 65 years of age. To evaluate and compare individual clinical characteristics various scores including the Hunt and Hess score, the Fisher score, and the Glasgow outcome scale were used., Results: A total of 347 patients were included in the final analysis. The control group included 290 patients, while 57 patients were in the older patient group. Neither the Hunt and Hess scores nor Fisher scores were significantly correlated to patient age. The Glasgow outcome scale was significantly lower in the older group after clipping of ruptured aneurysms (p < 0.000) but not significantly different after clipping of unruptured aneurysms (p = 0.793)., Conclusion: Postoperative Glasgow outcome scale scores were not significantly different after clipping of unruptured cerebral aneurysms approximately 1 cm in diameter in older patients compared to the younger age group. Therefore, clipping of unruptured cerebral aneurysms may also be a valuable treatment option for older patients., (© 2021. The Author(s).)

Background: Morphological irregularity is linked to intracranial aneurysm wall instability and manifests in the lumen shape. Yet there is currently no consent on how to assess shape irregularity. The aims of this work are to quantify irregularity as perceived by clinicians, to break down irregularity into morphological attributes, and to relate these to clinically relevant factors such as rupture status, aneurysm location, and patient age or sex., Methods: Thirteen clinicians and 26 laypersons assessed 134 aneurysm lumen segmentations in terms of overall perceived irregularity and five different morphological attributes (presence/absence of a rough surface, blebs, lobules, asymmetry, complex geometry of the parent vasculature). We examined rater agreement and compared the ratings with clinical factors by means of regression analysis or binary classification., Results: Using rank-based aggregation, the irregularity ratings of clinicians and laypersons did not differ statistically. Perceived irregularity showed good agreement with curvature (coefficient of determination R 2  = 0.68 ± 0.08) and was modeled very accurately using the five morphological rating attributes plus shape elongation (R 2  = 0.95 ± 0.02). In agreement with previous studies, irregularity was associated with aneurysm rupture status (AUC = 0.81 ± 0.08); adding aneurysm location as an explanatory variable increased the AUC to 0.87 ± 0.09. Besides irregularity, perceived asymmetry, presence of blebs or lobules, aneurysm size, non-sphericity, and curvature were linked to rupture. No association was found between morphology and any of patient sex, age, and history of smoking or hypertension. Aneurysm size was linked to morphology., Conclusions: Irregular lumen shape carries significant information on the aneurysm's disease status. Irregularity constitutes a continuous parameter that shows a strong association with the rupture status. To improve the objectivity of morphological assessment, we suggest examining shape through six different morphological attributes, which can characterize irregularity accurately.

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 I 2  = 86%). Overall mean size of 743 ruptured posterior circulation aneurysms was 6.2 mm (95% CI 5.3-7.0, residual I 2  = 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.

Background: Fusiform vertebrobasilar aneurysms (FVBAs) may exhibit a disastrous clinical course. Due to their rare occurrence, evidence concerning optimal management is lackluster., Objective: To describe the epidemiology, clinical features and treatment outcomes of a consecutive series of patients admitted to our institution., Methods: We retrospectively evaluated patient charts with respect to clinical presentation, treatment procedures, and the outcomes of all patients diagnosed with an FVBA, which were seen at our institution between March 2006 and February 2017., Results: Forty-five consecutive patients were analyzed. Follow-up was available for 39 patients (86.7%) with a median duration of 28.8 months. Seventeen patients (37.7%) were asymptomatic, 14 patients (31.1%) presented with brainstem ischemia, 8 patients (17.8%) with supratentorial ischemia, and 3 (6.7%) patients with brain stem compression. Aneurysm rupture occurred in 3 patients upon presentation (6.7%). Initially, 19 patients (42.2%) were significantly disabled with Modified Rankin Scale (mRS) scores ≥ 3. Twelve patients (26.7%) underwent invasive treatment: endovascular therapy in 9 cases and surgical treatment in 3 cases. Thirty-three patients received conservative treatment. During follow-up, 6 events (66.7%) of severe disability or death (mRS 4-6) occurred in the endovascular group versus 1 event (33%) in the surgical group versus 19 events (63.3%) among conservatively treated aneurysms. Deterioration was significantly more frequent in patients with symptomatic aneurysms (p = 0.030)., Conclusion: Patients harboring an FVBA frequently present with disabling symptoms caused by various pathomechanisms. The natural history is aggressive, mostly for initially symptomatic aneurysms, and periprocedural morbidity of surgical or endovascular treatment remains substantial.

Background: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease, leading to kidney failure. One of the most serious extrarenal complications of ADPKD is comorbid intracranial aneurysms. The aim of this study is to evaluate the prevalence, rupture rate, and treatment outcomes of intracranial aneurysms in ADPKD., Methods: Adult patients with a documented diagnosis of ADPKD who received kidney transplantation at our center from January 1994 to December 2018 were included in the study. Medical history, physical examination, laboratory findings, imaging studies, and operation records were collected and analyzed from our database., Results: Among 154 kidney transplant recipients with ADPKD, 113 (73.4%) patients were screened for intracranial aneurysms preoperatively. Twenty three patients (14.9%) had intracranial aneurysms with mean diameter size of 4.5 ± 2.7 mm. Nine patients (5.8%) experienced aneurysm rupture and the mean age at time of rupture was 34.9 ± 9.3 years. Twelve patients (52.2%) presented with multiple aneurysms. The most common aneurysm location was the bifurcation of the middle cerebral artery (34.9%). Clipping was the most common treatment in both ruptured and unruptured aneurysms., Conclusions: Intracranial aneurysms are more frequent in patients with ADPKD, and the average age of intracranial artery rupture in patients with ADPKD is earlier than in the general population. It is necessary to consider proper evaluation and management of intracranial aneurysms when counseling ADPKD patients who will undergo kidney transplantation.

Background: The most frequent neurological complication during coil embolization of a ruptured cerebral aneurysm is a thromboembolic event. The association between the tortuosity of the internal carotid artery (ICA) and thromboembolic events (TEEs) during coil embolization of ruptured cerebral aneurysms remains unclear. The present study aimed to investigate the association between extracranial ICA tortuosity and thromboembolic complications during coil embolization of anterior circulation ruptured aneurysms., Methods: A cohort of 57 patients with 57 anterior circulation ruptured aneurysms who underwent endovascular embolization at a single institution was retrospectively investigated. Patients were divided into two groups, those who experienced TEEs and those who did not that were compared and analyzed based on patient baseline characteristics, procedural factors, and anatomical factors including those of aneurysms and extracranial ICA tortuosity. The anatomical factors of the aneurysms included maximum dome size, neck width, dome-to-neck ratio, and dome-to-neck aspect ratio. Extracranial ICA angles in the proximal and distal curvature were evaluated as ICA tortuosity., Results: Three of the 57 patients were excluded because of unavailability of data regarding ICA tortuosity; 54 patients were finally evaluated. TEEs occurred in six patients with five anterior cerebral and one internal carotid aneurysms. The extracranial distal ICA angle was significantly larger in patients with TEEs than in those without. Procedural factors and anatomical factors of the aneurysms were not associated with TEEs., Conclusions: Extracranial ICA tortuosity was significantly associated with an increased incidence of thromboembolic events during endovascular coiling of anterior circulation ruptured aneurysms.

Background: The treatment of ruptured posterior circulation aneurysms remains challenging despite progresses in the endovascular and neurosurgical techniques., Objective: To provide epidemiological characterization of subjects presenting with ruptured posterior circulation aneurysms in Switzerland and thereby assessing the treatment patterns and neurological outcomes., Methods: This is a retrospective analysis of the Swiss SOS registry for patients with aneurysmal subarachnoid hemorrhage. Patients were divided in 3 groups (upper, lower, and middle third) according to aneurysm location. Clinical, radiological, and treatment-related variables were identified and their impact on the neurological outcome was determined., Results: From 2009 to 2014, we included 264 patients with ruptured posterior circulation aneurysms. Endovascular occlusion was the most common treatment in all 3 groups (72% in the upper third, 68% in the middle third, and 58.8% in the lower third). Surgical treatment was performed in 11.3%. Favorable outcome (mRS ≤ 3) was found in 56% at discharge and 65.7% at 1 year. No significant difference in the neurological outcome were found among the three groups, in terms of mRS at discharge (p = 0.20) and at 1 year (p = 0.18). High WFNS grade, high Fisher grade at presentation, and rebleeding before aneurysm occlusion (p = 0.001) were all correlated with the risk of unfavorable neurological outcome (or death) at discharge and at 1 year., Conclusions: In this study, endovascular occlusion was the principal treatment, with a favorable outcome for two-thirds of patients at discharge and at long term. These results are similar to high volume neurovascular centers worldwide, reflecting the importance of centralized care at specialized neurovascular centers.

Objective: Hypertension is common in patients with aneurysmal subarachnoid hemorrhage (SAH). However, it is still unclear whether premorbid antihypertensive therapy can help to reduce the risk of severe aneurysmal bleeding. Therefore, this study aims to assess the effect of premorbid hypertension control on outcome of patients with aneurysmal SAH., Methods: We retrospectively reviewed the clinical data of patients with intracranial aneurysms admitted to our institution from February 2012 to December 2017. Based on premorbid hypertension history and use of antihypertensive agents, all patients with aneurysmal SAH were divided into antihypertensive group and uncontrolled group. Patient characteristics, imaging features, clinical complication, and outcome were analyzed between the two groups., Results: A total of 348 patients with ruptured aneurysms were included in this study. Compared to those with premorbid controlled hypertension, patients with premorbid uncontrolled hypertension presented worse clinical grade, with more severe aneurysmal SAH and more frequent intracerebral hematoma. Patients receiving a treatment for ACEI type or ARB type of drugs in the antihypertensive group suffered from less amount of aneurysmal bleeding, while patients with grade 3 hypertension in the uncontrolled group suffered from more amount of aneurysmal bleeding. Patients with premorbid controlled hypertension had a lower incidence of rebleeding, hydrocephalus, and cerebral vasospasm, and had a lower rate of disability and mortality., Conclusions: Premorbid hypertension control is associated with favorable clinical outcome of patients with aneurysmal SAH. Besides, the ACEI type or ARB type of antihypertensive agents is associated with the less amount of bleeding after aneurysm rupture.

Background: For a treatment decision of unruptured cerebral aneurysms, physicians and patients need to weigh the risk of treatment against the risk of hemorrhagic stroke caused by aneurysm rupture. The aim of this study was to externally evaluate a recently developed statistical aneurysm rupture probability model, which could potentially support such treatment decisions., Methods: Segmented image data and patient information obtained from two patient cohorts including 203 patients with 249 aneurysms were used for patient-specific computational fluid dynamics simulations and subsequent evaluation of the statistical model in terms of accuracy, discrimination, and goodness of fit. The model's performance was further compared to a similarity-based approach for rupture assessment by identifying aneurysms in the training cohort that were similar in terms of hemodynamics and shape compared to a given aneurysm from the external cohorts., Results: When applied to the external data, the model achieved a good discrimination and goodness of fit (area under the receiver operating characteristic curve AUC = 0.82), which was only slightly reduced compared to the optimism-corrected AUC in the training population (AUC = 0.84). The accuracy metrics indicated a small decrease in accuracy compared to the training data (misclassification error of 0.24 vs. 0.21). The model's prediction accuracy was improved when combined with the similarity approach (misclassification error of 0.14)., Conclusions: The model's performance measures indicated a good generalizability for data acquired at different clinical institutions. Combining the model-based and similarity-based approach could further improve the assessment and interpretation of new cases, demonstrating its potential use for clinical risk assessment.

Purpose: Patients over the age of 80 years when diagnosed with an unruptured intracranial aneurysm (UIA) pose unique decision-making challenges due to shortened life-expectancy and increased risk of treatment. Thus, we investigated the risk of rupture and survival of a consecutive series of patients who were diagnosed with an UIA after the age of 80 years., Methods: Data of consecutive patients with an UIA were reviewed, and patients were included in our study if they were first evaluated for a UIA by the senior author during their ninth decade of life. Outcomes were aneurysm rupture and overall survival after diagnosis. Survival was estimated from a Kaplan-Meier survival curve. Incidence of risk factors was compared to a population of patients less than 65 years who were seen by the senior author over the same time period., Results: Eighty-three patients who were over 80 years when diagnosed with a UIA were included in this study. In our population, there is a risk of rupture of 3.2% per patient-year. One-, three-, and five-year survival rates for our population were estimated to be 92, 64, and 35%, respectively. When compared to patients under 65 years diagnosed with a UIA, "over 80" patients had a significantly higher incidence of hypertension, and a significantly lower incidence of smoking history and familial aneurysm history., Conclusions: In our study population, UIAs greater than 7 mm carry a non-negligible risk of rupture of 3.2% per patient-year, and further studies investigating the risk-to-benefit ratio of treatment in this population are warranted.

While cocaine use is thought to be associated with aneurysmal rupture, it is not known whether heroin use increases the risk of rupture in patients with non-mycotic saccular aneurysms. Our goal was to investigate the association between heroin and cocaine use and the rupture of saccular non-mycotic aneurysms. The medical records of 4701 patients with 6411 intracranial aneurysms, including 1201 prospective patients, diagnosed at the Brigham and Women's Hospital and Massachusetts General Hospital between 1990 and 2016 were reviewed and analyzed. Patients were separated into ruptured and non-ruptured groups. Univariable and multivariable logistic regression analyses were performed to determine the association between heroin, cocaine, and methadone use and the presence of ruptured intracranial aneurysms. In multivariable analysis, current heroin use was significantly associated with rupture status (OR 3.23, 95% CI 1.33-7.83) whereas former heroin use (with and without methadone replacement therapy), and current and former cocaine use were not significantly associated with intracranial aneurysm rupture. In the present study, heroin rather than cocaine use is significantly associated with intracranial aneurysm rupture in patients with non-mycotic saccular cerebral aneurysms, emphasizing the possible role of heroin in the pathophysiology of aneurysm rupture and the importance of heroin cessation in patients harboring unruptured intracranial aneurysms.

Background: Although research on pediatric intracranial aneurysms is well documented, studies of pediatric intracranial distal arterial aneurysms (PIDAAs) remain scarce., Methods: All pediatric patients (≤ 18 years) with intracranial aneurysms located distally to the M2 segment of the middle cerebral artery (MCA), A2 segment of the anterior cerebral artery, P2 segment of the posterior cerebral artery, and other cerebral arteries distal to the main branch who were treated at our center between January 2012 and April 2017 were retrospectively reviewed., Results: Thirty-five PIDAAs were observed in 35 patients with a mean age of 9.2 ± 5.9 years and a male ratio of 71.4% (n = 25). Sudden onset of severe headache was the most common symptom (n = 22, 62.9%), followed by seizures (n = 21, 60%). Twenty-seven patients (77.1%) had ruptured aneurysms, and 18 of them (66.7%) exhibited combined lobe intracerebral hematoma. MCA was the most common site (n = 23, 65.7%). Large or giant aneurysms were observed in 16 patients (45.7%). Eight patients (22.9%) had pseudoaneurysms, six of whom (75%) reported a head trauma history. Thirty patients (85.7%) had favorable outcomes at the end of the 6-month follow-up. Kaplan-Meier 6-month seizure curves revealed a significantly higher decrease in seizure rates in the surgical group than in the endovascular group (P = 0.036)., Conclusions: PIDAAs constitute a high proportion of pediatric intracranial aneurysms. PIDAAs are associated with an increased risk of seizures, a predilection for the MCA, and a high incidence of pseudoaneurysms with head trauma history. Surgical intervention is of greater benefit than endovascular treatment in controlling the risk of seizures.

Background: Intracranial aneurysms at the posterior communicating artery (PCOM) are known to have high rupture rates compared to other locations. We developed and internally validated a statistical model discriminating between ruptured and unruptured PCOM aneurysms based on hemodynamic and geometric parameters, angio-architectures, and patient age with the objective of its future use for aneurysm risk assessment., Methods: A total of 289 PCOM aneurysms in 272 patients modeled with image-based computational fluid dynamics (CFD) were used to construct statistical models using logistic group lasso regression. These models were evaluated with respect to discrimination power and goodness of fit using tenfold nested cross-validation and a split-sample approach to mimic external validation., Results: The final model retained maximum and minimum wall shear stress (WSS), mean parent artery WSS, maximum and minimum oscillatory shear index, shear concentration index, and aneurysm peak flow velocity, along with aneurysm height and width, bulge location, non-sphericity index, mean Gaussian curvature, angio-architecture type, and patient age. The corresponding area under the curve (AUC) was 0.8359. When omitting data from each of the three largest contributing hospitals in turn, and applying the corresponding model on the left-out data, the AUCs were 0.7507, 0.7081, and 0.5842, respectively., Conclusions: Statistical models based on a combination of patient age, angio-architecture, hemodynamics, and geometric characteristics can discriminate between ruptured and unruptured PCOM aneurysms with an AUC of 84%. It is important to include data from different hospitals to create models of aneurysm rupture that are valid across hospital populations.

Background: Over the years, the consensus has generally been that Finland is a country with a significantly high incidence of aneurysmal subarachnoid haemorrhage (SAH) when compared to the rest of the world, excluding Japan. Most of the traditionally cited Finnish incidence studies are several decades old and have clear differences in their methodology and study design. The objective of this study was to determine the hospital-admitted incidence of aneurysmal SAH at Tampere University Hospital between 1990 and 2014. We also compared the incidence to other geographical regions in Finland., Methods: The material for this study consists of patients admitted to Tampere University Hospital between 1990 and 2014 with the presentation of aneurysmal SAH. There was a total of 1965 patients with aneurysmal SAH in our data., Results: The mean hospital-admitted aneurysmal SAH incidence over the period was 7.41 per 100,000 person-years. The hospital-admitted aneurysmal SAH incidence in the Eastern Finland region was two-thirds greater than in the Tampere University Hospital region., Conclusions: We observed a relatively steady hospital-admitted incidence of aneurysmal SAH (7.41 per 100,000 person-years) in the Tampere University Hospital region. This result is parallel to a recent study looking into the incidence of aneurysmal SAH for the whole of Finland. Compared to the Tampere University Hospital region, the incidence was 64% greater in the Eastern Finland region.

Introduction: To analyze whether the computed tomography angiography (CTA) spot sign predicts the intraprocedural rupture rate and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH)., Methods: From a prospective nationwide multicenter registry database, 1023 patients with aneurysmal subarachnoid hemorrhage (aSAH) were analyzed retrospectively. Descriptive statistics and logistic regression analysis were used to compare spot sign-positive and -negative patients with aneurysmal intracerebral hemorrhage (aICH) for baseline characteristics, aneurysmal and ICH imaging characteristics, treatment and admission status as well as outcome at discharge and 1-year follow-up (1YFU) using the modified Rankin Scale (mRS)., Results: A total of 218 out of 1023 aSAH patients (21%) presented with aICH including 23/218 (11%) patients with spot sign. Baseline characteristics were comparable between spot sign-positive and -negative patients. There was a higher clip-to-coil ratio in patients with than without aICH (both spot sign positive and negative). Median aICH volume was significantly higher in the spot sign-positive group (50 ml, 13-223 ml) than in the spot sign-negative group (18 ml, 1-416; p < 0.0001). Patients with a spot sign-positive aICH thus were three times as likely as those with spot sign-negative aICH to show an intraoperative aneurysm rupture [odds ratio (OR) 3.04, 95% confidence interval (CI) 1.04-8.92, p = 0.046]. Spot sign-positive aICH patients showed a significantly worse mRS at discharge (p = 0.039) than patients with spot sign-negative aICH (median mRS 5 vs. 4). Logistic regression analysis showed that the spot sign was an aICH volume-dependent predictor for outcome. Both spot sign-positive and -negative aICH patients showed comparable rates of hospital death, death at 1YFU and mRS at 1YFU., Conclusion: In this multicenter data analysis, patients with spot sign-positive aICH showed higher aICH volumes and a higher rate of intraprocedural aneurysm rupture, but comparable long-term outcome to spot sign-negative aICH patients.

Background: Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder associated with high incidences of intracranial aneurysms. We performed a systematic review with the purpose of clarifying the prevalence, risk of rupture, and appropriate management of intracranial aneurysms in the ADPKD population., Method: PRISMA guidelines were followed. We conducted a comprehensive literature search of three databases (PubMed, Ovid MEDLINE, and Ovid EMBASE) on all series reporting ADPKD patients with intracranial aneurysms., Results: Our systematic review included 16 articles with a total of 563 patients with ADPKD and intracranial aneurysms. The prevalence of unruptured aneurysms was 11.5% (95% CI = 10.1-13%), whereas 1.9% (95% CI = 1.3-2.6%) of aneurysms were ruptured. Hypertension was present in 79.3% of patients with ADPKD and renal impairment in 65%. The mean size of ruptured aneurysms was slightly higher than unruptured (6 mm vs. 4.4 mm). The most common locations of unruptured and ruptured aneurysms were the ICA (40.5%) and MCA (45%), respectively. Asymptomatic patients studied with four-vessel angiography experienced 25% transient complications. Overall, 74% unruptured aneurysms were surgically treated with lower complication rates compared to endovascular treatment (11% vs. 27.7%). Among conservatively treated aneurysms, 2.9% ruptured at follow-up (rupture rate 0.4%/patient-year). Finally, the growth rate was 0.4% per patient-year, and the incidence of de novo aneurysm formation was 1.4% per patient-year., Conclusions: The prevalence of unruptured intracranial aneurysms in the ADPKD population is approximately 11%. Given the non-negligible rate of procedural complications, the management of these patients must be cautious and individualised. The rupture rate appears comparable to that of the general population. On the other hand, the 1.4% rate per patient-year of de novo aneurysms is non-negligible. These findings should be considered when counselling ADPKD patients regarding the appropriate management of intracranial aneurysms.

Background: Aneurysms associated with brain arteriovenous malformations (bAVMs) influence the natural history of these lesions and pose important therapeutic challenges. However, the epidemiology, natural history, and appropriate management of the aneurysms associated with bAVMs are not completely understood due to the paucity of large and uniform studies. We performed a systematic review of published series examining the association between aneurysms and bAVMs with the purpose of clarifying the prevalence, risk of hemorrhage, and appropriate management of these lesions., Method: PRISMA/MOOSE guidelines were followed. We conducted a comprehensive literature search of three databases (PubMed, Ovid MEDLINE, and Ovid EMBASE) on aneurysms associated with bAVMs. Only studies examining consecutive case series of aneurysms associated with bAVMs were included. From the collected studies, we extracted data regarding prevalence of bAVM-associated aneurysms, risk of aneurysm rupture in relation to bAVM location and aneurysm characteristics, and treatment-related outcomes., Results: Our systematic review included 44 articles with a total of 10,093 bAVMs. The proportion of bAVMs with an associated aneurysm was 20.2 % (95 % CI = 19.4-20.9 %). Among ruptured bAVMs with associated aneurysms, the aneurysm was the source of hemorrhage in 49.2 % (95 % CI = 43.7-54.7 %) of cases. Flow-related aneurysms were the most common source of aneurysm rupture (78.5 %, 95 % CI = 70.6-84.9 %). Infratentorial bAVM-associated aneurysms presented a higher risk of rupture (60 %, 95 % CI = 47.4-71.9 %) when compared with supratentorial lesions (29 %, 95 % CI = 21.4-38.5 %). Endovascular treatment of aneurysms associated with bAVMs had a cure rate of 80.0 % (95 % CI = 73.3-85.3 %), complication rate of 8.7 % (95 % CI = 5.5-13.1 %), and a good neurological outcome rate of 78.8 % (95 % CI = 72.5-83.9 %)., Conclusions: Twenty percent of bAVMs harbored arterial aneurysms. The presence of aneurysm increases the risk of bleeding of the bAVM, especially when flow-related or infratentorially located. Aneurysms associated with bAVMs should be treated promptly. Selective endovascular treatment of bAVM-associated aneurysms appears safe and effective.

Background: Multiple intracranial aneurysms (MIAs) are associated with poorer outcomes after rupture than are single intracranial aneurysms (SIAs). Although the risk factors for intracranial aneurysm rupture have been widely investigated, few studies have focused on MIAs. Thus, the present study aimed to determine whether there are differences in the patient and aneurysm characteristics between those with ruptured and unruptured anterior circulation MIAs (AC-MIAs)., Method: The present study included 97 patients with AC-MIAs (58 ruptured, 39 unruptured). Data regarding patient characteristics, aneurysm location, mirror aneurysms (MirAns), and bleb formations were collected from medical records and angiography images. Three-dimensional (3D) geometries generated with a 3D Slicer were evaluated to determine the range of morphological parameters. A univariate analysis was conducted to identify significant differences between the groups and receiver-operating characteristic (ROC) analyses were performed for each morphological parameter., Results: There are significantly fewer patients younger than 40 years of age in the ruptured group (P = 0.04); although the groups did not significantly differ with regard to smoking and hypertension, the ruptured group included significantly more current smokers who smoked more than 20 cigarettes per day (P = 0.025) and significantly more patients with a history of hypertension but an irregular use of anti-hypertensive medications (P = 0.043). Ruptured AC-MIAs were more likely to be located in the internal carotid artery (ICA) communicating artery (ICA C7) and anterior communicating artery (AComA; P = 0.000), to have formed a pair of MirAns (P = 0.001), and to have a bleb formation (P = 0.000). In terms of morphological parameters, the two groups differed significantly regarding aneurysm size (P = 0.000), neck width (P = 0.016), bottleneck factor (BNF; P = 0.000), height/width ratio (H/W; P = 0.031), aspect ratio (AR; P = 0.000) and size ratio (SR; P = 0.000). Additionally, the ROC analyses revealed that the optimal threshold size for rupture was 4.00 mm and that the SR had the highest area under the curve (AUC) value (0.826)., Conclusions: The present study found that current smokers who smoked more than 20 cigarettes per day and those with hypertension but an irregular use of anti-hypertensive medications were more likely to suffer from rupture. Aneurysm location and bleb formation were closely related to the rupture of AC-MIAs, and SR was a better predictor of AC-MIAs rupture status than size, neck width, BNF, H/W and AR. These findings should be verified by future prospective follow-up studies of AC-MIAs.

Background: Several studies have included different co-morbid conditions in prediction models for stroke patients. For subarachnoid haemorrhage (SAH), it is not known whether the Charlson Co-morbidity Index (CCI) is associated with outcome. We evaluated if this index was associated with outcome in patients with ruptured intracerebral aneurysms., Methods: The data of all consecutive aneurysmal SAH (aSAH) patients treated at the Radboudumc, Nijmegen, The Netherlands and entered in the database were retrospectively analysed. Clinical condition at admission was recorded using the WFNS (World Federation of Neurological Surgeons Grading System) grade was collected, as were the age and treatment modality. The burden of co-morbidity was retrospectively registered using the CCI. Outcome was dichotomised on the modified Rankin Scale (mRS; 0-2, favourable outcome; 3-6, unfavourable outcome). A binary logistic regression analysis was performed., Results: Between 6th May 2008 and 31st July 2013, 457 patients were admitted because of non-traumatic SAH (aSAH). Seventy-seven (16.8 %) patients had no aneurysm. Of the 380 patients with aSAH, information on co-morbid conditions was available for 371 patients. Thirty-six of those 371 had no treatment because of: bad clinical condition in 34 (9.2 %), a non-treatable dissecting aneurysm in 1 (0.3 %) and the explicit wishes of another. Co-morbidity was present in 113 (31.5 %) patients. Binary logistic regression analysis revealed no added value of using the CCI in predicting the outcome (p = 0.91)., Conclusions: This study reports that the CCI is not associated with the outcome classified on the mRS at 6 months in patients after aSAH. The CCI has no added value in case-mix correction.

Background: Endovascular treatment of intracranial aneurysms can be technically challenging in cases of wide necks or unfavorable dome-to-neck ratio. Coils deployed without supporting devices may herniate from the aneurysm sac into the parent artery, causing thromboembolic complications or vessel occlusion. Therefore, alternative strategies for managing wide-necked aneurysms have been introduced such as stent-assisted coil embolization (SAC), balloon-assisted coil embolization (BAC), and double-catheter coil embolization (DCC)., Methods: SAC, BAC, or DCC were used to treat 201 patients with 207 wide-neck aneurysms between 2008 and 2013. Initial occlusion rates, recanalization rates, and periprocedural complications were retrospectively evaluated. The mean follow-up periods for SAC, BAC, and DCC were 16.2 months, 11.6 months, and 14.3 months, respectively., Results: Clinical and anatomical analyses were conducted in 201 patients with 207 anuerysms. Complete occlusion rates of SAC, DCC, and BAC were 63.8 %, 46.7 %, and 63.2 %, respectively, and incomplete occlusion rates were 13.4 %, 15.5 %, 10.5 %, respectively (p value = 0.798). No rebleeding or hemorrhage occurred after coil embolization. Recanalization rates did not differ among the SAC, DCC, and BAC groups (7.1 % vs. 11.1 % vs. 7.9 %, p value = 0.696). Statistically insignificant results were observed in the rate of periprocedural complications among SAC, DCC, and BAC (11.0 % vs. 13.3 % vs. 15.8 %, p value = 0.578)., Conclusions: There were no significant differences in the recurrence rate and periprocedural complication rate, and no rebleeding or aneurysmal rupture after treatment. Sufficient occlusion rates were achieved with SAC, DCC, and BAC. Notably, DCC does not require the use of antiplatelet agents and achieves coil stability without compromising the parent artery or major branch. Thus, we believe that the double-catheter technique was found to be a feasible and safe treatment modality for branching wide-neck aneurysms.

Background: Spontaneous, non traumatic subarachnoid hemorrhage (SAH) is a significant clinical problem that occurs most commonly as a result of aneurysm rupture. In approximately 15 % of cases, nor aneurysm or other vascular malformation can be identified by cerebral angiography as origin of the hemorrhage, and these are commonly defined as idiopathic SAH (ISAH). Because of the negative angiography, limited extension of the bleeding with prevalent prepontine pattern and the benign prognosis, the venous causes has been preferred rather than the arterial ones. In the literature recent studies have suggested a possible contribution by primitive variants of Basal vein of Rosenthal (BVR) in its the pathogenesis of ISAH, commonly grouped according Watanabe classification (type A, B and C). In this paper we evaluated the prevalence of anatomical variants of BVR in ISAH., Methods: Venous drainage at angiography was retrospectively analyzed in 40 patients with ISAH and in 40 with unruptured aneurysms as controls., Results and Conclusions: Previous studies displayed a significant prevalence of BVR type C variants in ISAH. Conversely in our study we recognized variant B as prevalent, in which the BVR bifurcates to drain anteriorly into the uncal vein and posteriorly into the Galenic system. Similarly to variant C (in which the BVR drains via perimesencephalic "bridging" veins into cavernous, sphenoparietal, petrosal sinus or directly into transverse sinus) also variant B might be subjected to those stress mechanisms and intrinsic system 'fragility' and for reasons yet to determine, sets off a consequent hemorrhage with clinical and radiological features typical of ISAH.

Background: We aimed to assess the prevalence of unruptured intracranial aneurysms (UIAs) in healthy asymptomatic adults, and investigate the differences in incidence due to gender and age in Japan., Methods: Magnetic resonance angiography (MRA) results of healthy asymptomatic adults who underwent the procedure for examination of the brain, from April 2010 to March 2012, were retrospectively examined. Patients with a history of ruptured aneurysm and UIAs were excluded. UIAs greater than 2.0 mm in size were counted. In accordance with these criteria, 8,696 people with a mean age of 52.2±9.5 years were examined, and 37.4 % of these individuals were women., Results: The overall prevalence of UIAs was 3.2 %. The prevalence in women was higher than that in men (4.4 % versus 2.5 %, OR, 1.81; 95% CI, 1.4 to 2.31). The prevalence increased with age in both genders. In under 49 years, the prevalence in women and men were 2.7 % and 1.9 %, respectively, with no significant differences (OR, 1.47; CI, 0.91 to 2.37). In over 50 years, the prevalence in women was higher than that in men (5.4 % versus 2.8 %, OR, 2.01; CI, 1.52–2.67). There were significant differences in the locations of UIAs by gender (P <0.001); Internal carotid artery was more frequent in women, whereas anterior cerebral artery and middle cerebral artery were more common inmen., Conclusions: This study provides etiological data on the prevalence of UIAs in healthy asymptomatic Japanese adults, and may be useful in determining therapeutic managements for UIAs.

Background: The natural history, including growth and rupture, of unruptured intracranial aneurysms (UIAs) remains unknown. Here, we present the results of serial magnetic resonance angiography (MRA) follow-up study in 111 patients with 136 UIAs., Method: A total of 111 patients with 136 UIAs were followed annually over the past 12 years, using 1.5-Tesla MRA. Follow-up was ended when UIAs were treated surgically, or the patients died of subarachnoid hemorrhage or other causes. Various factors influencing aneurysm rupture or growth were examined statistically., Results: Aneurysm rupture and growth occurred in six and 13 of the 111 patients, respectively. Annual rupture rate was 1.8 % per year and annual growth rate was 3.9 % per year. Aneurysm size was the sole factor influencing rupture(H.R. 1.214, 95 % CI, 1.078-1.368) and multiplicity was the sole factor influencing aneurysm growth (H.R. 5.174, 95 % CI 1.81-14.80)., Conclusions: Serial MRA study showed that the incidence of UIA growth was twice as high as that of UIA rupture. As four patients showed aneurysm rupture or growth within 1 year, further investigations are necessary to determine the optimum interval of radiological investigation and to identify which UIAs grow or rupture within a short time.

Background: Elective temporary clipping (ETC) is increasingly used in surgery for aneurysms. This study was to assess whether the impact of ETC on intraoperative aneurysmal rupture (IAR) translates into neurological outcome., Methods: Patients who underwent surgery for ruptured anterior circulation aneurysms were prospectively studied for various factors related to ETC, IAR and neurological outcome at 3 months. Univariate and multivariate analyses were performed using SPSS20., Results: Of the total 273 ruptured aneurysm surgeries studied, IAR was observed in only six out of 132 aneurysms (4.5 %) who had ETC, compared with 78 out of 141 (55.3 %) without ETC (p < 0.001). Aneurysms complicated by IAR had significantly longer clipping time (8.3 min) compared with those without IAR (1.9 min) (p < 0.001). IAR had significant association with unfavorable outcome (38 % vs. 24 %) (p = 0.02). Patients with ETC had significantly shorter clipping time (2.9 min) compared with those without ETC (4.8 min) (p = 0.02). Unfavorable outcome was noted in 30 out of 132 with ETC (23 %), compared with 48 out of 141 without ETC (34 %) (p = 0.04). This beneficial effect was nonsignificantly greater in younger and good clinical grade patients. While episodes of ETC within clipping time of 20 min did not show significant difference in outcome, repeated rescue clipping (45 % unfavorable outcome, p = 0.048) and total clipping time of at least 20 min (75 % unfavorable outcome, p = 0.008) had significant impact on outcome. In multivariate analysis, the use of ETC (p = 0.027) and total temporary clipping less than 20 min (p = 0.049) were noted to result in significantly better outcome, independent of other factors., Conclusions: The use of ETC decreased the occurrence of IAR and the total clipping time, thereby leading to significantly better outcome, independent of other factors. While repeated elective clipping within total clipping time of 20 min did not influence outcome, repeated rescue clipping and total clipping time of at least 20 min had significant impact on outcome.

Background: Verbal memory is an essential cognitive ability with scope for adequate treatment of information and for orientation in everyday life. Our study is centered on memory performance in the wake of treatment for ruptured intracranial aneurysm., Methods: Three psychological tests were performed: (1) within a month of the neurosurgical intervention, (2) 1 year and (3) 5-7 years after the ruptured aneurysm treatment. Under comparison are the overall results of tests for verbal memory capacity in a cohort of patients (N = 59) and in the control group., Results: Three post-treatment measurements revealed a persistent deficit of verbal memory. The cohort's average performance improved from -1.3 SD (standard deviation) below the average of the norm to -0.5 SD below the norm at the second test 1 year after treatment, while at the third test the deficit had worsened to -0.68 SD. Similarly, testing for long-term recovery at 5-7 years postoperatively showed the patients' performances to be 2/3 SD below the average of the general population., Conclusions: The results of the study imply the need for long-term rehabilitation of memory in this particular group of patients.

Background: The purpose of this retrospective population-based study was to investigate the incidence of subarachnoid haemorrhage from small (5 mm and below) cerebral aneurysms and their localisation in consecutive patients surgically treated in the State of Vorarlberg/Austria., Methods: Altogether, during the last 4 years, 82 patients after spontaneous subarachnoid haemorrhage (mean age 53.7 years, range 21-84 years, 47 females and 35 males) were referred to the Neurosurgical Department of the Academic Teaching Hospital Feldkirch, serving for all 360,000 inhabitants of the State (corresponding to a subarachnoid haemorrhage incidence of 5.7/100,000/year). In 70 patients (85.4%), a cerebral aneurysm was detected by computed tomography angiography and/or digital cerebral angiography. Out of these, 47 patients (66.2%, mean age 52.1 years, range 24-77 years) were treated with aneurysm clipping and included in the study. Preoperatively, computed tomography, computed tomography angiography and/or digital cerebral angiography were assessed for amount of blood, aneurysm size and localisation, respectively. Clinical status was graded according to the Hunt and Hess classification at admission and according to the Glasgow Outcome Scale at discharge., Findings: According to Koivisto categories, 18 aneurysms were localised at the anterior cerebral artery, 17 aneurysms at the middle cerebral artery, 11 at the internal carotid artery, and 1 at the vertebrobasilar artery. The mean aneurysm diameter was 7.7 mm (range 3-30 mm). In 34% of the aneurysms the diameter was 5 mm or smaller (n = 16), in 51% between 6 and 10 mm (n = 24) and in 15% between 11 and 30 mm (n = 7). Only 1/17 ruptured middle cerebral artery aneurysms (5.9%), 4/11 internal carotid artery aneurysms (36.4%) and the vertebrobasilar artery aneurysm were small. However, in 10/18 anterior cerebral artery aneurysms (55.6%) the diameter was 5 mm or below., Conclusions: In conclusion, in our consecutive patient series with clipped cerebral aneurysms after subarachnoid haemorrhage, one third had small ruptured aneurysms, with the anterior cerebral artery complex as the main predilection site. Therefore, despite the previously reported low rupture risk, incidental small aneurysms should also be considered for therapy, depending on localisation and individual risk factors.

Background: Numerous studies with conflicting results have tried to prove the influence of seasonal variations or different meteorological factors on the occurrence of aneurysmal subarachnoidal hemorrhage (SAH). The aim of this study was to establish a mathematical model of a series of aneurysmal rupture dates in different patients and verify a temporal pattern in the occurrence of SAH., Methods: We analyzed a group of 563 patients with the exact aneurysm rupture dates, hospitalized at the Clinic of Neurosurgery, Clinical Center of Vojvodina, Novi Sad, Serbia, between January 1, 1998 and December 31, 2009. After the monthly distributions, we evaluated the period between two subsequent rupture dates., Results: The absolute number of SAH per month varied between 0 and 10. The monthly seasonal indices show a fluctuation of the time series (with the peak in March and nadir in September), but the median values of the number of aneurysm ruptures in a particular month did not differ significantly. The time scale of the aneurysm rupture dates shows that the most frequent interval between subsequent ruptures was 1 day (in 75 cases or 13.34%). Following this period, the number of days between ruptures showed a gradually decreasing pattern that could be approximated by exponential distribution., Conclusions: The results are a clear confirmation that SAH patients do indeed present in clusters in a restricted population area. This exact clustering in our series is not particularly connected to month or season, yet strongly supports the existence of a temporal pattern in SAH occurrence.

Background: Working with patients with intracranial aneurysms, we have developed a clinical suspicion that there may be differences in the rupture rate of aneurysms depending on the aneurysm's anatomical location. The aim of the study was to examine the anatomical distribution of ruptured and unruptured intracranial aneurysms in a defined population., Method: We retrospectively included all patients with an aneurysm treated in our institution between 1 January 1990 and 31 December 1999, and collected the relevant data from the individual patient files. With the Koivisto categories for aneurysm location, we gathered the aneurysms into four categories: ACA, MCA, ICA, and VBA., Findings: Four hundred forty-four aneurysms were included in the study: 361 in SAH patients and 83 in patients without SAH. ACA aneurysms were over-represented in the ruptured group (36.0% vs. 9.6%, p < 0.0001). MCA aneurysms were more frequent in the unruptured group (51.8% vs. 29.6%, p < 0.0002). Ruptured ACA aneurysms were over-represented among males (p < 0.0001), whereas ruptured ICA aneurysms were more frequent among females (p < 0.0001). Ruptured aneurysms in the posterior circulation were more frequently found on the left side (p < 0.0001)., Conclusion: This study shows that the anatomical distribution of aneurysms is different in SAH patients compared with patients with unruptured aneurysms. Haemodynamic features of the vessel of origin may explain the differences we have found. Furthermore, this study suggests that it is of particular importance to treat patients with incidentally found ACA aneurysms.

Background: Many industrialized countries are facing a volumetric growth of the senior population. We studied the trends in the incidence and outcome of subarachnoid haemorrhage (SAH) in patients aged >or=70 years., Method: We retrospectively reviewed the cases of 1030 patients registered in the Nagasaki SAH Data Bank from 1989 to 1993 and 1274 patients registered from 1994 to 1998., Findings: The annual age-adjusted incidence of SAH per 100,000 increased only in women, from 15.4 in the 1989-1993 period to 19.7 in the 1994-1998 period. The average annual incidence of SAH per 100,000 women in the elderly aged >or=70 years increased significantly from 44.3 in the first period to 58.2 in the second period. In patients aged >or=70 years, the proportion of high-grade SAH (Hunt & Kosnik Grade IV and V) significantly increased from 27.2% in the first 5 years to 38.2% in the second 5 years. In patients aged<70 years, it increased slightly from 23.4% to 26.7%. The rate of favorable outcomes significantly fell from 43.9% (first period) to 30.9% (second period) in patients aged >or=70 years but was stable in patients aged<70 years., Interpretation: Although the incidence of elderly patients with SAH in our study is compatible with or higher than that of other reports, we believe that elderly patients (especially women) with high-grade SAH may not have all been identified. When we discuss the management of ruptured and unruptured aneurysms in the elderly, we should bear these trends of SAH in mind.

A retrospective analysis of ruptured cerebral aneurysms among the hospital population of Lithuania was performed. A total of 507 patients were enrolled in the study during a 5 year period. The unadjusted annual incidence of ruptured cerebral aneurysms was found to be 2.7/100,000 in the hospital population of Lithuania and 3.9/100,000 in the hospital population of the defined area of the city of Kaunas. Overall management results showed a 45. 6% good recovery and 31.6% death rate in this group of patients. Surgical results showed a 52.1% good outcome and 20.9% death rate. Despite the fact that the death rate according to the timing of surgery after the initial subarachnoid haemorrhage did not differ significantly (p >0.05) among early (0-3 days post SAH), moderate (4-7 days post SAH) and late (more than 7 days post SAH) surgery groups, it was found that 75 (14.8%) patients deteriorated while awaiting surgery. Initial bleeding together with rebleeding, medical complications and vasospasm were the main causes of death, constituting 61.3%, 18.1% and 9.4% of all deaths, respectively. The results of this study showed that the annual incidence of ruptured cerebral aneurysms in Lithuania is similar to that in other European countries except for Finland. Overall management results in the Lithuanian hospital population indicated only a slight improvement compared to management results of previous population-based studies in other countries.

A retrospective analysis of 111 patients with aneurysms associated with Moyamoya disease is presented. The subjects comprised of our 12 cases and 99 other well-documented cases. These 111 cases had 131 aneurysms. There were 48 males and 63 females. The average age was 40.3 years. The clinical manifestations were intracranial haemorrhage in 99 cases (89%), and ischaemic events in 9 cases (8%), but no mention was made of these in the last three cases (2%). The Hunt and Kosnik grades were grade 1 in 8%, grade 2 in 23%, grade 3 in 31%, grade 4 in 35%, and grade 5 in 3%. Of the 131 aneurysms, 73 (56%) were found distributed around the circle of Willis, 24 (18%) in the basal ganglia, 29 (22%) on collateral vessels, and 5 (4%) on other vessels. Forty-six percent of the cases were treated surgically, 51% conservatively, and 3% by endovascular procedures. The surgical procedures for the aneurysms were; neck clipping in 49%, aneurysmectomy in 18%, wrapping of the aneurysm in 11%, coating or cautery of the aneurysm in 7%, and revascularization only in 11%. The outcomes were Glasgow Outcome Scale 1 in 30%, 2 in 22%, 3 in 11%, 4 in 1%, and 5 in 25%. The main reasons for the unfavourable outcome were initial poor clinical grade and rebleeding. Follow-up angiography of 25 aneurysms demonstrated that all aneurysms in the basal ganglia or on the collateral vessels disappeared. We recommend surgical intervention for aneurysms associated with Moyamoya disease to prevent rupture or rebleeding, especially for aneurysms around the circle of Willis. However, direct surgery is not recommended for aneurysms found in the basal ganglia or on the collateral vessels.

A retrospective review of patients presenting to our institution with aneurysmal subarachnoid hemorrhage between 1980-1990 was accomplished. Eleven variables were examined as to their relationship to clinical vasospasm: age, sex, clinical grade, amount of subarachnoid blood on CT, aneurysm location, incidence of vasospasm, incidence of complications, use of calcium channel blockers, time to surgery, length of stay, and outcome. Data were analyzed with univariate and multivariate logistical regression methodology. By univariate analysis, age under 20, amount of subarachnoid hemorrhage, and clinical grade were associated with a higher risk of vasospasm. Using multivariate logistic regression, these factors, along with age under 35, were correlated as being predictive of clinical vasospasm. When all patients are grouped into either good or bad outcome, and a similar analysis is performed, only in the poor outcome group is the amount of subarachnoid hemorrhage and clinical grade correlated with vasospasm. This suggests that there is a group of patients with a predisposition to vasospasm that is independent of subarachnoid hemorrhage and clinical grade, and that these patients may have a more favorable outcome.