Kelly B. Mahaney, Robert D. Brown Jr., Irene Meissner, David G. Piepgras, John Huston III, Jie Zhang and James C. Torner
The aim of this study was to determine age-related differences in short-term (1-year) outcomes in patients with unruptured intracranial aneurysms (UIAs).
Four thousand fifty-nine patients prospectively enrolled in the International Study of Unruptured Intracranial Aneurysms were categorized into 3 groups by age at enrollment: < 50, 50–65, and > 65 years old. Outcomes assessed at 1 year included aneurysm rupture rates, combined morbidity and mortality from aneurysm procedure or hemorrhage, and all-cause mortality. Periprocedural morbidity, in-hospital morbidity, and poor neurological outcome on discharge (Rankin scale score of 3 or greater) were assessed in surgically and endovascularly treated groups. Univariate and multivariate associations of each outcome with age were tested.
The risk of aneurysmal hemorrhage did not increase significantly with age. Procedural and in-hospital morbidity and mortality increased with age in patients treated with surgery, but remained relatively constant with increasing age with endovascular treatment. Poor neurological outcome from aneurysm- or procedure-related morbidity and mortality did not differ between management groups for patients 65 years old and younger, but was significantly higher in the surgical group for patients older than 65 years: 19.0% (95% confidence interval [CI] 13.9%–24.4%), compared with 8.0% (95% CI 2.3%–13.6%) in the endovascular group and 4.2% (95% CI 2.3%–6.2%) in the observation group. All-cause mortality increased steadily with increasing age, but differed between treatment groups only in patients < 50 years of age, with the surgical group showing a survival advantage at 1 year.
Surgical treatment of UIAs appears to be safe, prevents 1-year hemorrhage, and may confer a survival benefit in patients < 50 years of age. However, surgery poses a significant risk of morbidity and death in patients > 65 years of age. Risk of endovascular treatment does not appear to increase with age. Risks and benefits of treatment in older patients should be carefully considered, and if treatment is deemed necessary for patients older than 65 years, endovascular treatment may be the best option.
Irene Meissner, James Torner, John Huston III, Michele L. Rajput, David O. Wiebers, Lyell K. Jones Jr., Robert D. Brown Jr. and the International Study of Unruptured Intracranial Aneurysms Investigators
Investigators conducting the International Study of Unruptured Intracranial Aneurysms, sponsored by the National Institutes of Health, sought to evaluate predictors of future hemorrhage in patients who had unruptured mirror aneurysms. These paired aneurysms in bilateral arterial positions mirror each other; their natural history is unknown.
Centers in the US, Canada, and Europe enrolled patients for prospective assessment of unruptured intracranial aneurysms. Central radiological review confirmed the presence or absence of mirror aneurysms in patients without a history of prior subarachnoid hemorrhage (SAH) (Group 1). Outcome at 1 and 5 years and aneurysm characteristics are compared.
Of 3120 patients with aneurysms treated in 61 centers, 376 (12%) had mirror aneurysms, which are more common in women than men (82% [n = 308] vs 73% [n = 1992], respectively; p <0.001) and in patients with a family history of aneurysm or SAH (p <0.001).
Compared with patients with nonmirror saccular aneurysms, a greater percentage of patients with mirror aneurysms had larger (>10 mm) aneurysms (mean maximum diameter 11.7 vs 10.4 mm, respectively; p <0.001). The most common distribution for mirror aneurysms was the middle cerebral artery (34% [126 patients]) followed by noncavernous internal carotid artery (32% ), posterior communicating artery (16% ), cavernous internal carotid artery (13% ), anterior cerebral artery/anterior communicating artery (3% ), and vertebrobasilar circulation (2% ). When these patients were compared with patients without mirror aneurysms, no statistically significant differences were found in age (mean age 54 years in both groups), blood pressure, smoking history, or cardiac disease. Aneurysm rupture rates were similar (3.0% for patients with mirror aneurysms vs 2.8% for those without).
Overall, patients with mirror aneurysms were more likely to be women, to report a family history of aneurysmal SAH, and to have larger aneurysms. The presence of a mirror aneurysm was not an independent predictor of future SAHs.
David O. Wiebers, David G. Piepgras, Robert D. Brown Jr., Irene Meissner, James Torner, Neal F. Kassell, Jack P. Whisnant, John Huston III and Douglas A. Nichols
Lisa Anne Cannon-Albright
Robert D. Brown JR., John Huston III, Richard Hornung, DR.P.H., Tatiana Foroud, David F. Kallmes, Dawn Kleindorfer, Irene Meissner, Daniel Woo, Laura Sauerbeck, Joseph Broderick and for the Familial Intracranial Aneurysm (FIA) Investigators
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.
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 ≥ 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.
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).
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.
Jason Mackey, Robert D. Brown Jr., Charles J. Moomaw, Laura Sauerbeck, Richard Hornung, Dheeraj Gandhi, Daniel Woo, Dawn Kleindorfer, Matthew L. Flaherty, Irene Meissner, Craig Anderson, E. Sander Connolly, Guy Rouleau, David F. Kallmes, James Torner, John Huston III and Joseph P. Broderick
Familial predisposition is a recognized nonmodifiable risk factor for the formation and rupture of intracranial aneurysms (IAs). However, data regarding the characteristics of familial IAs are limited. The authors sought to describe familial IAs more fully, and to compare their characteristics with a large cohort of nonfamilial IAs.
The Familial Intracranial Aneurysm (FIA) study is a multicenter international study with the goal of identifying genetic and other risk factors for formation and rupture of IAs in a highly enriched population. The authors compared the FIA study cohort with the International Study of Unruptured Intracranial Aneurysms (ISUIA) cohort with regard to patient demographic data, IA location, and IA multiplicity. To improve comparability, all patients in the ISUIA who had a family history of IAs or subarachnoid hemorrhage were excluded, as well as all patients in both cohorts who had a ruptured IA prior to study entry.
Of 983 patients enrolled in the FIA study with definite or probable IAs, 511 met the inclusion criteria for this analysis. Of the 4059 patients in the ISUIA study, 983 had a previous IA rupture and 657 of the remainder had a positive family history, leaving 2419 individuals in the analysis. Multiplicity was more common in the FIA patients (35.6% vs 27.9%, p < 0.001). The FIA patients had a higher proportion of IAs located in the middle cerebral artery (28.6% vs 24.9%), whereas ISUIA patients had a higher proportion of posterior communicating artery IAs (13.7% vs 8.2%, p = 0.016).
Heritable structural vulnerability may account for differences in IA multiplicity and location. Important investigations into the underlying genetic mechanisms of IA formation are ongoing.