Familial intracranial aneurysms

Intracranial Mirror Aneurysm: Epidemiology, Rupture Risk, New Imaging, Controversies, and Treatment Strategies

There are some controversies about the surgical treatment strategy of mirror aneurysms. Whether to choose 1-stage or 2-stage surgery, bilateral or unilateral craniotomy, or surgical or interventional treatment are the main points in dispute. In this review, the different surgery strategies faced by patients are discussed. Different surgical methods are adopted based on the patient's individual state and the location and size of the aneurysm. A new imaging method is introduced using 3D Slicer, which clearly recognizes the relationship among aneurysm, brain tissue, skull, and nerve. The 3D Slicer can help surgeons undertake adequate preoperative preparation. In addition, we also introduce some ruptured factors (e.g., age, gender, hypertension, morphologic, and hemodynamic) concerning mirror aneurysm. Systematic discussion of the controversies and methods in surgical treatment of mirror aneurysms may provide new perspectives in future research for the prevention and treatment of mirror aneurysms.

Patient and aneurysm characteristics in familial intracranial aneurysms. A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Patient and aneurysm characteristics have been reported to differ between patients with familial and non-familial intracranial aneurysms (IAs), although results are inconsistent. We systematically reviewed and meta-analyzed the literature to identify and quantify patient- and aneurysm characteristics associated with familial IAs.

METHODS

We searched PubMed and EMBASE for case-control and cohort studies comparing patient- and aneurysm characteristics between familial and non-familial IAs. Two observers independently assessed study eligibility and appraised quality with the Newcastle Ottawa Scale. With univariable weighted linear regression analysis we calculated β-coefficients with corresponding 95% confidence intervals (CIs) for ruptured and unruptured IAs combined and for ruptured IAs only. Heterogeneity was assessed with Higgins I2.

RESULTS

A total of 15 articles were included in the meta-analysis in which 16,346 patients were analyzed with a total of 14,225 IAs. For ruptured and unruptured IAs combined, multiple IAs were more prevalent in familial (28.5%) than in non-familial IAs (20.4%; β = 0.10, 95% CI, 0.04 to 0.16; I2 0%). For ruptured IAs only, in familial patients IAs were more prevalent on the middle cerebral artery (41.1% versus 29.5%; β = 0.12, 95% CI, 0.01 to 0.24; I2 12%) and ruptured at a younger age (46.5 years versus 50.8 years; β = -5.00, 95% CI, -9.31 to -0.69; I2 98%) than in non-familial patients. No significant differences were found for the proportion of women, size of the aneurysm at time of rupture, smoking or hypertension.

CONCLUSION

These results suggest that characteristics of familial and non-familial IAs show considerable overlap, yet differ on specific aspects. However, results for age at rupture showed considerable heterogeneity. These findings should be taken into consideration for future etiological research into IAs.

Management of Unruptured Intracranial Aneurysms

Unruptured intracranial aneurysms (UIA) occur in approximately 2-3 % of the population. Most of these lesions are incidentally found, asymptomatic and typically carry a benign course. Although the risk of aneurysmal subarachnoid hemorrhage is low, this complication can result in significant morbidity and mortality, making assessment of this risk the cornerstone of UIA management. This article reviews important factors to consider when managing unruptured intracranial aneurysms including patient demographics, comorbidities, family history, symptom status, and aneurysm characteristics. It also addresses screening, monitoring, medical management and current surgical and endovascular therapies.

Difference in Aneurysm Characteristics between Patients with Familial and Sporadic Aneurysmal Subarachnoid Haemorrhage

Object

Patients with familial intracranial aneurysms (IA) have a higher risk of rupture than patients with sporadic IA. We compared geometric and morphological risk factors for aneurysmal rupture between patients with familial and sporadic aneurysmal subarachnoid hemorrhage (aSAH) to analyse if these risk factors contribute to the increased rupture rate of familial IA.

Methods

Geometric and morphological aneurysm characteristics were studied on CT-angiography in a prospectively collected series of patients with familial and sporadic aSAH, admitted between September 2006 and September 2009, and additional patients with familial aSAH retrieved from the prospectively collected database of familial IA patients of our center. Odds ratios (OR) with corresponding 95% confidence intervals (95% CI) were calculated to compare the aneurysm characteristics between patients with familial and sporadic aSAH.

Results

We studied 67 patients with familial and 184 with sporadic aSAH. OR’s for familial compared with sporadic aSAH were for oval shape 1.16(95%CI:0.65–2.09), oblong shape 0.26(95%CI:0.03–2.13), irregular shape 0.83(95%CI:0.47–1.49), aspect ratio ≥ 1.6 0.94(95%CI:0.54–1.66), contact with the perianeurysmal environment (PAE) 1.15(95%CI:0.56–2.40), deformation by the PAE 1.05(95%CI:0.47–2.35) and for dominance of the posterior communicating artery (PCoA) in case of PCoA aneurysms 1.97(95% CI:0.50–7.83).

Conclusions

The geometric and morphological risk factors for aneurysm rupture do not have a higher prevalence in familial than in sporadic aSAH and thus do not explain the increased risk of IA rupture in patients with familial IA. We recommend further search for other potential risk factors for rupture of familial IA, such as genetic factors.

Association of morphologic and demographic features of intracranial aneurysms with their rupture: a retrospective analysis

BACKGROUND

In spite of its common occurrence, the factors predictive of the rupture of intracranial aneurysms (IAs) remain poorly defined.

METHOD

A retrospective analysis of patients admitted with a primary diagnosis of cerebral aneurysm in a single institution was done. The factors studied were age, sex, size, site, side, multiplicity, neck type, aspect ratio, positive family history, smoking and drinking habits, and hypertension. The morphological parameters were evaluated for a total of 5,138 aneurysms obtained from the 2,347 patients. Factors found significant on univariate analysis were further tested on a multivariate model.

FINDINGS

We found 1,088 patients (46.36%) had at least a single aneurysmal rupture. Among the morphologic factors, size greater than 10 mm, right sidedness, aspect ratio greater than 1.6, deviated neck type, and multiplicity were found to be associated with higher incidences of rupture. Aneurysms on posterior communicating and middle cerebral arteries were found to be more prone to rupture. The demographic factors that were more linked with the ruptured aneurysms were positive family history, smoking, and hypertension.

CONCLUSIONS

Relevant cases should be started on intensive lifestyle modification, and extensive screening of those with a positive family history is highly warranted. All "at-risk" patients should be evaluated for early surgical intervention.

A mathematical model of utility for single screening of asymptomatic unruptured intracranial aneurysms at the age of 50 years

BACKGROUND

Although rupture of intracranial aneurysms carries high mortality and morbidity rates, the clinical and financial benefit of screening certain high-risk groups is uncertain. We designed a mathematical model to interrogate the clinical benefit and cost-effectiveness of screening.

METHODS

A decision tree analysis model was used to calculate the outcome and cost of two scenarios applied to the same population: one-off screening for intracranial aneurysms versus not screening. Each scenario had an associated gain or loss of Quality Adjusted Life Years (QALY) and cost; the difference between the two scenarios was calculated. The variable inputs were the aneurysm prevalence and risk of rupture after 5 years. Sensitivity analyses were performed to determine the effects of altering various factors on outcomes.

RESULTS

Screening of the asymptomatic general population results in a QALY loss, equating to a negative clinical impact. The threshold 5-year risk of rupture at which screening resulted in a gain in QALYs was 13 %. This held true for any prevalence between 1 and 25 %. Risk of rupture had a greater impact on outcome than prevalence. Halving the risk of intervention (either surgery or coiling) reduced the threshold 5-year risk of rupture at which screening results in gain of QALYs to 6 %. The age of screening also had important effects on outcome.

CONCLUSIONS

The QALY benefit and cost-effectiveness of screening are most sensitive to the 5-year risk of rupture. Screening is beneficial only in populations with a high risk of rupture; this should be the focus of future research.

The case for family screening for intracranial aneurysms

Given that relatives of patients with intracranial aneurysms (IAs) or subarachnoid hemorrhage have a greater risk of harboring an aneurysm, family screening has become a common practice in neurosurgery. Unclear data exist regarding who should be screened and at what age and interval screening should occur. Multiple factors including the natural history of IAs, the risk of treatment, the cost of screening, and the psychosocial impact of finding an aneurysm should be taken into account when family screening is considered. In this paper, the authors review the current literature regarding risk factors and natural history of sporadic and familial aneurysms. Based on these data the authors assess current recommendations for screening and propose their own recommendations.

Current imaging assessment and treatment of intracranial aneurysms

OBJECTIVE

This article reviews current neuroimaging techniques used for screening, diagnosis, and follow-up of patients with intracranial aneurysms as well as neuroendovascular therapeutic options available to patients.

CONCLUSION

The diagnosis and management of intracranial aneurysms have evolved dramatically in the past 20 years. MR angiography and CT angiography allow radiologists to reliably and noninvasively diagnose most intracranial aneurysms. Nonoperative endovascular techniques for treating intracranial aneurysms are now making treatment increasingly safer and more effective.