Risk factors for aneurysmal subarachnoid hemorrhage in patients in Izumo City, Japan

OBJECT: The annual incidence of aneurysmal subarachnoid hemorrhage (SAH) in Izumo City, Japan, appears to be the highest rate among those reported; therefore the author investigated the risk factors for SAH in patients in this city. METHODS: A case-control study of 247 patients (108 men and 139 women with ages ranging from 28-96 years) with aneurysmal SAH was conducted in Izumo between 1980 and 1998. Hypertension, diabetes mellitus, heart disease, liver disease, cigarette smoking, alcohol consumption, and serum levels of total cholesterol, aspartate aminotransferase, alanine aminotransferase, and urea nitrogen were assessed as possible risk factors for SAH by using conditional logistic regression. After adjustment for other risk factors, results of multivariate analysis showed that hypertension was the most powerful risk factor, regardless of age and sex. The odds ratio for hypertension was higher in women than in men. The second greatest risk factors were cigarette smoking in those 59 years of age or younger and in men and hypercholesterolemia in those 60 years of age or older and in women. Among individuals 60 years of age or older and among women, diabetes mellitus and heart disease were inversely associated with the risk of SAH. When analyses were performed in 219 cases of confirmed ruptured cerebral aneurysm, very similar results were obtained. CONCLUSIONS: Among patients in Izumo, hypertension was the most notable risk factor for aneurysmal SAH, regardlessof age and sex, followed by cigarette smoking in younger men and hypercholesterolemia in older women. In older women, diabetes mellitus and heart disease decreased the risk of SAH.     

Risk factors for the formation of multiple intracranial aneurysms

OBJECT: Several factors are known to increase the risk of subarachnoid hemorrhage (SAH) and spontaneous intracerebral hematoma. However, information on the roles of these same factors in the formation of multiple aneurysms is less well defined. The purpose of this study was to examine factors associated with an increased risk of multiple aneurysm formation. METHODS: A retrospective review of the medical records of all patients with a diagnosis of SAH and intracranial aneurysms who were admitted to a single institution between 1985 and 1997 was undertaken. The authors examined associations between risk factors (patient age and sex, menopausal state of female patients, hypertension, cigarette smoking, alcohol consumption, history of cardiovascular disease or diabetes mellitus, and family history of cerebrovascular disease) and the presence of multiple aneurysms by using the Fisher exact test and logistic regression analysis. Of 400 patients admitted with a diagnosis of cerebral aneurysms, 392 were included in the study (287 women and 105 men). Two hundred eighty-four patients harbored a single aneurysm and 108 harbored multiple aneurysms (2 aneurysms in 68 patients, three aneurysms in 22 patients, four aneurysms in 13 patients, and five aneurysms in five patients). CONCLUSIONS: Statistical analysis revealed that, as opposed to the occurrence of a single aneurysm, there was a significant association between the presence of multiple aneurysms and hypertension (p < 0.001), cigarette smoking (p < 0.001), family history of cerebrovascular disease (p < 0.001), female sex (p < 0.001), and postmenopausal state in female patients (p < 0.001).     

Cigarette smoking increases the risk of developing a cerebral aneurysm and of subarachnoid hemorrhage]

Despite recent advances in diagnostic and therapeutic techniques, subarachnoid hemorrhage (SAH) is still a serious condition associated with high mortality and morbidity. There are no effective treatments other than surgical intervention. However, another option for decreasing the occurrence of SAH may be prevention of aneurysms formation and of their rupture by controlling risk factors. Cigarette smoking has been recently shown to be one of the major risk factors for SAH. We investigated whether cigarette smoking increased the risk of developing cerebral aneurysms and of SAH. Degree of smoking was investigated in 182 patients with SAH and in 123 patients with an unruptured cerebral aneurysm incidentally detected during investigation of other diseases. Sixty-nine patients with other diseases who were shown to be free of cerebral aneurysms through MR angiography served as controls. Smoking significantly increased the risk of both aneurysm formation and SAH; The odds ratio for SAH was 2.4, and for unruptured cerebral aneurysm 1.7. Smoking especially increased the occurrence of SAH in women and in youngsters. However, smoking did not influence the occurrence of cerebral vasospasm and multiplicity of aneurysms. These data suggest the importance of avoiding smoking to prevent the occurrence of cerebral aneurysms and of SAH.     

De novo formation and rupture of an azygos pericallosal artery aneurysm. Case report

An azygos pericallosal artery (APCA) aneurysm is a rare anomaly that is closely associated with saccular aneurysms. This is the earliest report to document de novo formation and rupture of an aneurysm at the bifurcation of an unpaired pericallosal trunk. The authors report the case of a woman who presented at the age of 52 years with subarachnoid hemorrhage (SAH) from the rupture of a newly formed APCA bifurcation aneurysm, 7 years after she had undergone surgery to clip a ruptured anterior cerebral artery aneurysm. De novo formation of aneurysms after SAH rarely occurs and certain risk factors like multiple and familial aneurysms, arterial hypertension, or smoking have been postulated. Late follow-up examination with angiography to detect de novo aneurysms should be considered in patients with this vascular anomaly after SAH.     

Size of ruptured intracranial saccular aneurysms in patients in Izumo City,Japan

BackgroundA community-based study was conducted to evaluate the factors related to the size of ruptured aneurysms and the effects of aneurysm size on clinical features.MethodsData from 358 patients with subarachnoid hemorrhage (SAH) treated between 1980 and 1998 in Izumo, Japan, were reviewed. In 285 of these patients, the sizes of the ruptured aneurysms were determined.ResultsAneurysm diameter was less than 5 mm in 68 patients, at least 5 to less than 10 mm in 137 patients, and 10 mm or more in 80 patients. Aneurysm size tended to increase with patient age. Age (≥60 years of age) and cigarette smoking were independently associated with aneurysms of 5 mm or more in diameter. Multiple aneurysms were positively and anterior cerebral artery aneurysms were inversely related to aneurysms of 10 mm or more in diameter. The larger the aneurysm, the worse was the World Federation of Neurosurgical Societies grade. The risk of rebleeding was higher in patients with larger (≥10 mm) aneurysms than in those with smaller (<10 mm) aneurysms. The incidences of diffuse severe SAH on computed tomographic scans in patients with SAH alone, symptomatic vasospasm, and hydrocephalus were higher in patients with larger (≥5 mm) aneurysms than in those with smaller (<5 mm) aneurysms. The larger the aneurysm, the worse was either functional outcome or the 6-month and 2-year survival rates.ConclusionAge, cigarette smoking, multiple aneurysms, and aneurysm site appear to be related to the size of ruptured aneurysms. Patients with larger aneurysms seem to have a worse clinical condition and more severe SAH, resulting in higher incidences of rebleeding, symptomatic vasospasm and hydrocephalus, and a worse outcome.     

Screening of risk groups for discovering intracranial aneurysms before rupture

In development of intracranial aneurysms contribute genetic factors together with smoking, hypertension, diabetes mellitus. Epidemiology studies suggest that as many as 5% of people harbour a cerebral aneurysm by age 75. Rupture of cerebral aneurysm is the most frequent cause of spontaneous subarachnoid haemorrhage (up to 80%.) Annual incidence of SAH is 10-14/100 000, but only 15-20% of aneurysms will rupture, and that will happen probably between 40-60 years. The morbidity and mortality of aneurismal subarachnoid (SAH) continues to be high. It is not possible to predict who has aneurysm and is it going to bleed or not, but it is possible to reveal high risk groups (polycystic kidney disease, Ehlers-Danlos sy, Marphan sy, family history of cerebral aneurysms, suspect de novo aneurysm formation in patients with prior history of cerebral aneurysm). Reviewing data from literature and reporting cases from each group with high risk, that have been screened and aneurysms discovered, authors wish to focus interest on this matter and propose screening program for these groups of patients. The mortality and morbidity in cases treated before rupture is significantly lower than after SAH, so screening programs could save many lives. According to our preliminara data, mostly based on control angiographies after 8-10 zears in patients previouslz operated for intracranial aneurysmas, from 15 angipgraphies 4 revealed new aneurysms (26% in 10 years period) with total number of 6 de novo formed aneurysms, which is not valid due to small number of patients but strongly suggests the importancy of screening program for risk groups.     

Factors associated with aneurysm size in patients with subarachnoid hemorrhage: effect of smoking and aneurysm location

OBJECTIVE: Intracranial aneurysm size is an important determinant of risk of rupture and outcome after rupture. Risk factors influencing aneurysm formation and growth are not well defined. In this study, we examined the association between known risk factors for cerebrovascular disease and size of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage. METHODS: We analyzed prospectively collected data from the placebo-treated group in a multicenter clinical trial conducted at 54 neurosurgical centers in North America. The presence, location, and size of intracranial aneurysms were determined by review of the admission angiograms. Pertinent information regarding the presence of various cerebrovascular risk factors was collected for each patient. Using logistic regression analysis, we identified independent determinants of aneurysm size from demographic, clinical, and angiographic characteristics of the participants. The impact of aneurysm size on 3-month mortality was analyzed after adjusting for potential confounding factors. RESULTS: For 298 patients admitted with subarachnoid hemorrhage, the ruptured aneurysms were graded as small (<13 mm) in 235 patients (79%) and large (> or =13 mm) in 63 patients (21%). In the logistic regression model, both smoking at any time (odds ratio, 2.2; 95% confidence interval, 1.1-4.5) and middle cerebral artery origin (odds ratio, 2.5; 95% confidence interval, 1.3-4.9) were independently associated with large aneurysms. Neither hypertension, diabetes mellitus, nor alcohol and illicit drug use were associated with large-sized aneurysms. After adjusting for initial Glasgow Coma Scale score and age in the logistic regression model, the presence of large-sized aneurysms was independently associated with 3-month mortality (odds ratio, 2.3; 95% confidence interval, 1.1-4.8). CONCLUSION: Cigarette smoking and middle cerebral artery origin seem to increase the risk for developing large aneurysms in patients predisposed to intracranial aneurysm formation. Further studies are required to investigate the mechanism underlying the association between cigarette smoking and intracranial aneurysm formation.     

Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture

OBJECT: The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed. METHODS: One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using life-table analyses and Cox's proportional hazards regression models including time-dependent covariates. The median follow-up time was 19.7 years (range 0.8-38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1-1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93-1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04-2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21-7.66, p = 0.02). CONCLUSIONS: Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.     

Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture

OBJECT: The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed. METHODS: One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using lifetable analyses and Cox's proportional hazards regression models including time-dependent covariates. The median follow-up time was 19.7 years (range 0.8-38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1-1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93-1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04-2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21-7.66, p = 0.02). CONCLUSIONS: Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.     

Epidemiological features and diagnostic evaluation of intracranial aneurysms

Female gender and cigarette smoking appear to be risk factors for the development of multiple intracranial aneurysms. An acquired nature is likely in this form. The mechanism of aneurysm formation in patients with sickle cell anemia is apparently different. These patients also present multiple aneurysms that show propensity for vertebrobasilar territory and appear at a younger age. Familial cerebral aneurysms are diagnosed once heritable connective tissue disorders have been excluded. The age of patients tends to be lower and the size of aneurysm to be smaller at the time of rupture in the familial form. These aneurysms are less frequently found in the anterior communicating artery than the sporadic aneurysms. A high incidence of asymptomatic familial aneurysms was detected in people with family histories of intracranial aneurysms studied by means of magnetic resonance angiography. Furthermore, familial aneurysms are more likely to rupture in families having members with aneurysmal subarachnoid hemorrhage (SAH) than in those without. The results of an interesting study using color "power" transcranial Doppler ultrasound in patients with aneurysmal SAH suggest that as the intracranial pressure diminished, the size of the aneurysm increased, and there was relatively little change between maximum and minimum dimensions during the cardiac cycle, i.e., the pulsatility is reduced. The use of postoperative angiography after clipping is a matter of debate. The indication more widely accepted is in large aneurysms with a wide neck, in which incomplete clipping can be suspected. Taking into account the current low risk of angiography in centers of excellence, its routine use may be recommended. Aneurysm remnants, vessel occlusion, vasospasm, and newly identified aneurysms are the main findings that were reported.     

Risk factors for subarachnoid hemorrhage

OBJECTIVE: Cigarette smoking has been demonstrated to increase the risk of subarachnoid hemorrhage (SAH). Whether cessation of smoking decreases this risk remains unclear. We performed a case-control study to examine the effect of smoking and other known risk factors for cerebrovascular disease on the risk of SAH. METHODS: We reviewed the medical records of all patients with a diagnosis of SAH (n = 323) admitted to Johns Hopkins Hospital between January 1990 and June 1997. Controls matched for age, sex, and ethnicity (n = 969) were selected from a nationally representative sample of the Third National Health and Nutrition Examination Survey. We determined the independent association between smoking (current and previous) and various cerebrovascular risk factors and SAH by use of multivariate logistic regression analysis. A separate analysis was performed to determine associated risk factors for aneurysmal SAH. RESULTS: Of 323 patients admitted with SAH (mean age, 52.7+/-14 yr; 93 were men), 173 (54%) were hypertensive, 149 (46%) were currently smoking, and 125 (39%) were previous smokers. In the multivariate analysis, both previous smoking (odds ratio [OR], 4.5; 95% confidence interval [CI], 3.1-6.5) and current smoking (OR, 5.2; 95% CI, 3.6-7.5) were significantly associated with SAH. Hypertension was also significantly associated with SAH (OR, 2.4; 95% CI, 1.8-3.1). The risk factors for 290 patients with aneurysmal SAH were similar and included hypertension (OR, 2.4; 95% CI, 1.8-3.2), previous smoking (OR, 4.1; 95% CI, 2.7-6.0), and current smoking (OR, 5.4; 95% CI, 3.7-7.8). CONCLUSION: Hypertension and cigarette smoking increase the risk for development of SAH, as found in previous studies. However, the increased risk persists even after cessation of cigarette smoking, which suggests the importance of early abstinence from smoking.     

A comparison of risk factors in the etiology of mirror and nonmirror multiple intracranial aneurysms

BACKGROUND: Pure mirror intracranial aneurysms represent a subgroup of multiple aneurysm patients where a congenital predisposition may play a major etiologic role. The aim of this study was to compare the pattern of prevalence of known risk factors for aneurysm disease between pure mirror and pure nonmirror multiple aneurysm populations. METHODS: Clinical records of all patients with multiple intracranial aneurysms admitted to our institution between January 1985 and September 2001 were reviewed. Age, localization of aneurysms, gender, and history of cigarette smoking or hypertension were noted and compared using Fisher's exact test and logistic regression analysis. RESULTS: There were 33 patients presented with pure mirror aneurysms (MirAn) and 49 with nonmirror multiple aneurysms (nMirAn). Average age of rupture occurred in the 5th decade in both groups. Female:male ratio was 3.1:1 in MirAn; 2.1:1 in nMirAn. In MirAn patients younger than 40 years it was 1:1. Smoking was the most prevalent risk factor in nMirAn (59.2%). In MirAn this was true only for patients in the 5th or 6th decades (65%), and hypertension was the most prevalent risk factor over that age (62.5%). A total of 80% of mirror aneurysm patients under 40 years had no known extrinsic risk factor, compared with 20% in nMirAn (p < 0.05). CONCLUSIONS: Differences in the relative prevalence of risk factors between both groups supports the hypothesis of a different etiologic process occurring in mirror aneurysm disease. Early rupture in patients with no extrinsic risk factors lends support to the role of a congenital predisposition over degenerative causes in these patients.     

Aetiology of intracranial saccular aneurysms in childhood.

Intracranial saccular aneurysms in childhood are rare neurosurgical lesions, occurring in 1-3% of large epidemiological aneurysm series. Analysis of previous reports indicates several distinct characteristics of this entity. First, there is a predominant male:female ratio approaching 2:1. Second, a disproportionately high number of these aneurysms arise at peripheral locations on the arterial tree. Third, approximately half of them are large or even giant aneurysms. These identifiable characteristics suggest that aneurysms in the younger age group may be a distinct pathophysiological entity from aneurysm in the adult population. In adults, epidemiological evidence indicates that 'acquired' factors such as hypertension, cigarette smoking, alcohol consumption, and oral contraceptive use together with 'intrinsic' or 'vascular' factors are causally related to the formation and rupture of cerebral aneurysms. Inherently, some of the 'acquired' factors must be of minor importance in aneurysm formation and rupture in childhood, whereas the 'intrinsic' factors may have a greater importance.     

Prevalence of risk factors for aneurysmal subarachnoid haemorrhage: results of a Japanese multicentre case control study for stroke

The pathogenesis of subarachnoid haemorrhage (SAH) is still unclear. To evaluate the risk factors for aneurysmal SAH, we conducted a multicentre case control study. All aneurysms were detected by cerebral angiography and the patients with SAH other than ruptured aneurysms were excluded. Information on past medical histories and other possible risk factors for SAH were assessed by a structured questionnaire. Data on the total 127 pairs (59 male and 68 female) were analysed. In a univariate analysis, family history of SAH [odds ratio (OR) 9.45], systemic hypertension (OR 2.65), cigarette smoking (OR 2.54) and regular alcohol consumption (OR 1.92) were significant risk factors for aneurysmal SAH. Heavy alcohol consumption (>350 g ethanol/week) was significant (OR 3.22), whereas light consumption (=<350 g/week) did not to increase the risks (OR 0.95). Both light (<20 cigarettes/day, OR 2.44) and heavy smoking (>=20 cigarettes/day, OR 2.72) were associated with an increased risk of SAH. In a multivariate analysis, after adjustment for other risk factors, family history of SAH, cigarette smoking and hypertension remained significant.     

Rupture of intracranial aneurysms during treatment with Guglielmi detachable coils: incidence, outcome, and risk factors

OBJECT: The aim of this study was to assess the incidence and outcome of procedure-related rupture of intracranial aneurysms in patients treated with Guglielmi detachable coils (GDCs) and to identify risk factors for this complication. METHODS: Procedure-related rupture occurred in seven of 264 treated aneurysms in 239 consecutive patients. Aneurysm size, history of previous subarachnoid hemorrhage (SAH) caused by the treated aneurysm, timing of treatment after SAH, and the use of a temporary occlusion balloon in the seven procedures in which rupture occurred were compared with the remaining 257 procedures, and these findings were correlated with data from 13 studies in the literature, in which results of 2030 aneurysm treatments were reported. CONCLUSIONS: Procedure-related rupture of intracranial aneurysms during GDC treatment occurs in 2.5% of cases and is responsible for 1% of treatment-related deaths. Risk factors are as follows: small aneurysm size, previous SAH, and probably the use of a temporary occlusion balloon.     

Retrospective analysis of the prevalence of asymptomatic cerebral aneurysm in 4518 patients undergoing magnetic resonance angiography--when does cerebral aneurysm develop?

The natural history of cerebral aneurysms was investigated by measuring the prevalence of incidentally found unruptured aneurysms in the general population and evaluating the characteristics including risk factors. 'De novo' formation of aneurysm was also demographically estimated. The prevalence of incidental aneurysm was evaluated among 4518 patients who underwent magnetic resonance (MR) angiography for various reasons in a neurosurgical institute. Double the number of patients were randomly selected from the remaining patients without aneurysm as the Control group so that sex and age group were matched to the Aneurysm group. 127 patients (2.8%) had diagnoses of aneurysm. The prevalence of asymptomatic aneurysm among middle-aged and elderly patients was predominant in women and increased with age in both sexes. Patients with aneurysms had significantly more hypertension and family history of subarachnoid hemorrhage compared to the controls. The prevalence was markedly increased in the 8th decade in men and the 7th decade in women, and new aneurysms seemed to develop predominantly around these decades. Cerebral aneurysms become detectable on MR angiography in the middle or later decades, and women tend to develop aneurysm earlier than men. Hypertension and family history of subarachnoid hemorrhage are probably risk factors for the development of aneurysm.     

The natural history of abdominal aortic aneurysms and their risk of rupture

The UK Small Aneurysm Trial has shown that ultrasound surveillance is a safe management option for patients with small abdominal aortic aneurysms (4.0 to 5.5 cm in diameter), with an annual rupture rate of only 1%. We investigated baseline risk factors associated with aneurysm rupture in the 1090 trial patients and an additional 1167 patients enrolled in the UK Small Aneurysm Study. In this cohort of 2257 patients there were 103 cases of aneurysm rupture. After 3 years the annual rate of rupture was 2.2% (95% CI 1.7 to 2.8). The risk of rupture was independently and significantly associated with female sex (p < 0.001), larger initial aneurysm diameter (p < 0.001), current smoking (p = 0.01) and higher mean blood pressure (p = 0.01). Age, body mass index, serum cholesterol concentration and ankle/brachial pressure index were not associated with an increased risk of aneurysm rupture. The most surprising finding was that women had a 3-fold higher risk of aneurysm rupture than men. Effective control of blood pressure and cessation of smoking are two simple measures that are likely to diminish the risk of aneurysm rupture and improve the cardiovascular health of patients with abdominal aortic aneurysm.     

Prospective risk of hemorrhage in patients with vertebrobasilar nonsaccular intracranial aneurysm

OBJECT: Nonsaccular intracranial aneurysms (NIAs) are characterized by dilation, elongation, and tortuosity of intracranial arteries. Dilemmas in management exist due to the limited regarding the natural history of this disease entity. The objective of this study was to determine the prospective risk of subarachnoid hemorrhage (SAH) in patients with vertebrobasilar NIAs. METHODS: All patients with vertebrobasilar fusiform or dolichoectatic aneurysms that had been radiographically demonstrated between 1989 and 2001 were identified. These patients' medical records were retrospectively reviewed. A prospective follow-up survey was sent and death certificates were requested. Based on results of neuroimaging studies, the maximal diameter of the involved artery, presence of SAH, and measurements of arterial tortuosity were recorded. Nonsaccular intracranial aneurysms were classified according to their radiographic appearance: fusiform, dolichoectatic, and transitional. Dissecting aneurysms were excluded. The aneurysm rupture rate was calculated based on person-years of follow up. Predictive factors for rupture were evaluated using univariate analysis (p < 0.05). One hundred fifty-nine patients, 74% of whom were men, were identified. The mean age at diagnosis was 64 years (range 20-87 years). Five patients (3%) initially presented with hemorrhage; four of these patients died during follow up. The mean duration of follow up was 4.4 years (692 person-years). Nine patients (6%) experienced hemorrhage after presentation; six hemorrhages were definitely related to the NIA. The prospective annual rupture rate was 0.9% (six patients/692 person-years) overall and 2.3% in those with transitional or fusiform aneurysm subtypes. Evidence of aneurysm enlargement or transitional type of NIA was a significant predictor of lesion rupture. Six patients died within 1 week of experiencing lesion rupture. CONCLUSIONS: Risk of hemorrhage in patients harboring vertebrobasilar NIAs is more common in those with evidence of aneurysm enlargement or a transitional type of aneurysm and carries a significant risk of death.     

Screening for brain aneurysm in the Familial Intracranial Aneurysm study: frequency and predictors of lesion detection

OBJECT: Approximately 20% of patients with an intracranial saccular aneurysm report a family history of intracranial aneurysm (IA) or subarachnoid hemorrhage. A better understanding of predictors of aneurysm detection in familial IA may allow more targeted aneurysm screening strategies. METHODS: The Familial Intracranial Aneurysm (FIA) study is a multicenter study, in which the primary objective is to define the susceptibility genes related to the formation of IA. First-degree relatives (FDRs) of those affected with IA are offered screening with magnetic resonance (MR) angiography if they were previously unaffected, are > or = 30 years of age, and have a history of smoking and/or hypertension. Independent predictors of aneurysm detection on MR angiography were determined using the generalized estimating equation version of logistic regression. RESULTS: Among the first 303 patients screened with MR angiography, 58 (19.1%) had at least 1 IA, including 24% of women and 11.7% of men. Ten (17.2%) of 58 affected patients had multiple aneurysms. Independent predictors of aneurysm detection included female sex (odds ratio [OR] 2.46, p = 0.001), pack-years of cigarette smoking (OR 3.24 for 20 pack-years of cigarette smoking compared with never having smoked, p < 0.001), and duration of hypertension (OR 1.26 comparing those with 10 years of hypertension to those with no hypertension, p = 0.006). CONCLUSIONS: In the FIA study, among the affected patients' FDRs who are > 30 years of age, those who are women or who have a history of smoking or hypertension are at increased risk of suffering an IA and should be strongly considered for screening.     

Treatment for intracranial aneurysms

Aneurysm rupture is suspected in case of sudden, intense headache, sometimes associated with nausea or vomiting, focal neurologic deficit or loss of consciousness. Aneurysm rupture is a diagnostic and therapeutic emergency that has to be managed in highly specialized centers. Ruptured aneurysms have to be treated in emergency to avoid rebleeding. Endovascular approach is the first line treatment. The indications for treatment of unruptured have to be discussed according to several factors including patient's age, aneurysm size and location. Follow-up examinations are needed after aneurysm treatment (CTA, MRA, DSA). According to aneurysm risk factors, patients with aneurysms have to stop smoking and their blood pressure should be controlled on a regular basis and treated if needed.