Characteristic features of unruptured intracranial aneurysms: predictive 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.

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Growth and rupture of unruptured intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/2018.4.jns18687 ◽

2019 ◽

Vol 131 (3) ◽

pp. 843-851 ◽

Cited By ~ 11

Author(s):

Seppo Juvela

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Cigarette Smoking ◽

Intracranial Aneurysms ◽

Aneurysm Rupture ◽

Ruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

Aneurysm Growth ◽

Independent Risk Factors

OBJECTIVERisk factors for growth of unruptured intracranial aneurysms (UIAs) during a lifelong follow-up in relation to subsequent rupture are unknown. The author’s aim in this study was to investigate whether risk factors for UIA growth are different for those that lead to rupture than for those that do not.METHODSThe series consists of 87 patients with 111 UIAs diagnosed before 1979, when UIAs were not treated. A total follow-up time of the patients was 2648 person-years for all-cause death and 2182 years when patients were monitored until the first rupture, death due to unrelated causes, or the last contact (annual incidence of aneurysm rupture, 1.2%). The follow-up time between aneurysm measurements was 1669 person-years. Risk factors for UIA growth were analyzed in relation to subsequent rupture.RESULTSThe median follow-up time between aneurysm measurements was 21.7 years (range 1.2–51.0 years). In 40 of the 87 patients (46%), the UIAs increased in size ≥ 1 mm, and in 31 patients (36%) ≥ 3 mm. All ruptured aneurysms in 27 patients grew during the follow-up of 324 person-years (mean growth rates 6.1 mm, 0.92 mm/year, and 37%/year), while growth without rupture occurred in 13 patients during 302 follow-up years (3.9 mm, 0.18 mm/year, and 4%/year) and no growth occurred in 47 patients during 1043 follow-up years. None of the 60 patients without aneurysm rupture experienced one during the subsequent 639 follow-up years after the last aneurysm measurement. Independent risk factors for UIA growth (≥ 1 mm) in all patients were female sex (adjusted OR 3.08, 95% CI 1.04–9.13) and smoking throughout the follow-up time (adjusted OR 3.16, 95% CI 1.10–9.10), while only smoking (adjusted OR 4.36, 95% CI 1.27–14.99) was associated with growth resulting in aneurysm rupture. Smoking was the only independent risk factor for UIA growth ≥ 3 mm resulting in aneurysm rupture (adjusted OR 4.03, 95% CI 1.08–15.07). Cigarette smoking at baseline predicted subsequent UIA growth, while smoking at the end of the follow-up was associated with growth resulting in aneurysm rupture.CONCLUSIONSCigarette smoking is an important risk factor for UIA growth, particularly for growth resulting in rupture. Cessation of smoking may reduce the risk of devastating aneurysm growth.

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High-Resolution Vessel Wall Magnetic Resonance Imaging of Small Unruptured Intracranial Aneurysms

Journal of Clinical Medicine ◽

10.3390/jcm10020225 ◽

2021 ◽

Vol 10 (2) ◽

pp. 225

Author(s):

Łukasz Zwarzany ◽

Ernest Tyburski ◽

Wojciech Poncyljusz

Keyword(s):

Magnetic Resonance Imaging ◽

Risk Factors ◽

Magnetic Resonance ◽

High Resolution ◽

Vessel Wall ◽

Intracranial Aneurysms ◽

Aneurysm Rupture ◽

Resonance Imaging ◽

Aneurysm Wall ◽

Conventional Risk Factors

Background: We decided to investigate whether aneurysm wall enhancement (AWE) on high-resolution vessel wall magnetic resonance imaging (HR VW-MRI) coexists with the conventional risk factors for aneurysm rupture. Methods: We performed HR VW-MRI in 46 patients with 64 unruptured small intracranial aneurysms. Patient demographics and clinical characteristics were recorded. The PHASES score was calculated for each aneurysm. Results: Of the 64 aneurysms, 15 (23.4%) showed wall enhancement on post-contrast HR VW-MRI. Aneurysms with wall enhancement had significantly larger size (p = 0.001), higher dome-to-neck ratio (p = 0.024), and a more irregular shape (p = 0.003) than aneurysms without wall enhancement. The proportion of aneurysms with wall enhancement was significantly higher in older patients (p = 0.011), and those with a history of prior aneurysmal SAH. The mean PHASES score was significantly higher in aneurysms with wall enhancement (p < 0.000). The multivariate logistic regression analysis revealed that aneurysm irregularity and the PHASES score are independently associated with the presence of AWE. Conclusions: Aneurysm wall enhancement on HR VW-MRI coexists with the conventional risk factors for aneurysm rupture.

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Subarachnoid hemorrhage after surgical treatment of unruptured intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/2017.3.jns162984 ◽

2018 ◽

Vol 129 (2) ◽

pp. 490-497

Author(s):

Hidetoshi Matsukawa ◽

Hiroyasu Kamiyama ◽

Toshiyuki Tsuboi ◽

Kosumo Noda ◽

Nakao Ota ◽

...

Keyword(s):

Risk Factors ◽

Subarachnoid Hemorrhage ◽

Surgical Treatment ◽

Incidence Rate ◽

Intracranial Aneurysms ◽

Annual Incidence ◽

Annual Incidence Rate ◽

Excellent Outcome ◽

Unruptured Intracranial Aneurysms ◽

Average Annual Incidence

OBJECTIVEOnly a few previous studies have investigated subarachnoid hemorrhage (SAH) after surgical treatment in patients with unruptured intracranial aneurysms (UIAs). Given the improvement in long-term outcomes of embolization, more extensive data are needed concerning the true rupture rates after microsurgery in order to provide reliable information for treatment decisions. The purpose of this study was to investigate the incidence of and risk factors for postoperative SAH in patients with surgically treated UIAs.METHODSData from 702 consecutive patients harboring 852 surgically treated UIAs were evaluated. Surgical treatments included neck clipping (complete or incomplete), coating/wrapping, trapping, proximal occlusion, and bypass surgery. Clippable UIAs were defined as UIAs treated by complete neck clipping. The annual incidence of postoperative SAH and risk factors for SAH were studied using Kaplan-Meier survival analysis and Cox proportional hazards regression models.RESULTSThe patients’ median age was 64 years (interquartile range [IQR] 56–71 years). Of 852 UIAs, 767 were clippable and 85 were not. The mean duration of follow-up was 731 days (SD 380 days). During 1708 aneurysm years, there were 4 episodes of SAH, giving an overall average annual incidence rate of 0.23% (95% CI 0.12%–0.59%) and an average annual incidence rate of 0.065% (95% CI 0.0017%–0.37%) for clippable UIAs (1 episode of SAH, 1552 aneurysm-years). Basilar artery location (adjusted hazard ratio [HR] 23, 95% CI 2.0–255, p = 0.0012) and unclippable UIA status (adjusted HR 15, 95% CI 1.1–215, p = 0.046) were significantly related to postoperative SAH. An excellent outcome (modified Rankin Scale score of 0 or 1) was achieved in 816 (95.7%) of 852 cases overall and in 748 (98%) of 767 clippable UIAs at 12 months.CONCLUSIONSIn this large case series, microsurgical treatment of UIAs was found to be safe and effective. Aneurysm location and unclippable morphologies were related to postoperative SAH in patients with surgically treated UIAs.

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Clinical Risk Factors Affecting Procedure-Related Major Neurological Complications in Unruptured Intracranial Aneurysms

Yonsei Medical Journal ◽

10.3349/ymj.2015.56.4.987 ◽

2015 ◽

Vol 56 (4) ◽

pp. 987 ◽

Cited By ~ 18

Author(s):

E-Wook Jang ◽

Yong Bae Kim ◽

Joonho Chung ◽

Sang Hyun Suh ◽

Chang-Ki Hong ◽

...

Keyword(s):

Risk Factors ◽

Intracranial Aneurysms ◽

Neurological Complications ◽

Clinical Risk Factors ◽

Factors Affecting ◽

Clinical Risk ◽

Unruptured Intracranial Aneurysms

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Small (< 10-mm) incidentally found intracranial aneurysms, Part 1: reasons for detection, demographics, location, and risk factors in 212 consecutive patients

Neurosurgical FOCUS ◽

10.3171/2011.9.focus11234 ◽

2011 ◽

Vol 31 (6) ◽

pp. E3 ◽

Cited By ~ 18

Author(s):

Ioannis Loumiotis ◽

Anne Wagenbach ◽

Robert D. Brown ◽

Giuseppe Lanzino

Keyword(s):

Risk Factors ◽

Subarachnoid Hemorrhage ◽

Intracranial Aneurysms ◽

Imaging Techniques ◽

Imaging Study ◽

Consecutive Series ◽

Common Location ◽

Unruptured Intracranial Aneurysms ◽

Paraclinoid Aneurysms ◽

History Of

Object The widespread use of imaging techniques for evaluating nonspecific symptoms (vertigo, dizziness, memory concerns, unsteadiness, and the like) and focal neurological symptoms related to cerebrovascular disease has led to increased identification of asymptomatic incidentally discovered unruptured intracranial aneurysms (UIAs). The management of these incidental aneurysms is controversial and many factors need to be considered. The authors describe reasons leading to diagnosis, demographics, and risk factors in a large consecutive series of patients with small incidentally found UIAs. Methods The authors prospectively evaluated 335 patients harboring 478 small (< 10-mm) UIAs between January 2008 and May 2011. Patients with known aneurysms, possibly symptomatic aneurysms, arteriovenous malformation–related aneurysms, patients with a history of subarachnoid hemorrhage from another aneurysm, and patients harboring extradural aneurysms were excluded from the analysis. Only truly incidental small aneurysms (272 aneurysms in 212 patients) were considered for the present analysis. Data regarding the reason for detection, demographics, location, and presence of potential risk factors for aneurysm formation were prospectively collected. Results There were 158 female (74.5%) and 54 male (25.5%) patients whose mean age was 60.6 years (median 62 years). The most common reason for undergoing the imaging study that led to a diagnosis of the aneurysms was evaluation for nonspecific spells and symptoms related to focal cerebrovascular ischemia (43.4%), known/possible intracranial or neck pathology (24%), and headache (16%). The most common location (27%) of the aneurysm was the middle cerebral artery; the second most common (22%) was the paraclinoid internal carotid artery (excluding cavernous sinus aneurysms). Sixty-nine percent of patients were current or prior smokers, 60% had a diagnosis of hypertension, and 23% had one or more relatives with a history of intracranial aneurysms with or without subarachnoid hemorrhage. Conclusions Small incidental UIAs are more commonly diagnosed in elderly individuals during imaging performed to investigate ill-defined spells or focal cerebrovascular ischemic symptoms, or during the evaluation of known or probable unrelated intracranial/neck pathology. Hypertension, smoking, and family history of aneurysms are common in this patient population, and the presence of these risk factors has important implications for treatment recommendations. Although paraclinoid aneurysms (excluding intracavernous aneurysms) are uncommon in patients with ruptured intracranial aneurysms, this location is very common in patients with small incidental UIAs.

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Management of carotid artery stenosis in patients with coexistent unruptured intracranial aneurysms

Journal of Neurosurgery ◽

10.3171/2018.9.jns182155 ◽

2020 ◽

Vol 132 (1) ◽

pp. 94-97 ◽

Cited By ~ 2

Author(s):

Tiziano Tallarita ◽

Thomas J. Sorenson ◽

Lorenzo Rinaldo ◽

Gustavo S. Oderich ◽

Thomas C. Bower ◽

...

Keyword(s):

Carotid Artery ◽

Carotid Artery Stenosis ◽

Intracranial Aneurysms ◽

Early Period ◽

Aneurysm Rupture ◽

Artery Stenosis ◽

Consecutive Series ◽

Carotid Revascularization ◽

Unruptured Intracranial Aneurysms ◽

Risk Of Rupture

OBJECTIVEConcomitant unruptured intracranial aneurysms (UIAs) are present in patients with carotid artery stenosis not infrequently and result in unique management challenges. Thus, we investigated the risk of rupture of an aneurysm after revascularization of a carotid artery in a contemporary consecutive series of patients seen at our institution.METHODSData from patients who underwent a carotid revascularization in the presence of at least one concomitant UIA at our institution from 1991 to 2018 were retrospectively reviewed. Patients were evaluated for the incidence of aneurysm rupture within 30 days (early period) and after 30 days (late period) of carotid revascularization, as well as for the incidence of periprocedural complications from the treatment of carotid stenosis and/or UIA.RESULTSOur study included 53 patients with 63 concomitant UIAs. There was no rupture within 30 days of carotid revascularization. The overall risk of rupture was 0.87% per patient-year. Treatment (coiling or clipping) of a concomitant UIA, if pursued, could be performed successfully after carotid revascularization.CONCLUSIONSCarotid artery revascularization in the setting of a concomitant UIA can be performed safely without an increased 30-day or late-term risk of rupture. If indicated, treatment of the UIA can take place after the patient recovers from the carotid procedure.

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Headache outcomes following treatment of unruptured intracranial aneurysms: A prospective analysis

Cephalalgia ◽

10.1177/0333102411398155 ◽

2011 ◽

Vol 31 (10) ◽

pp. 1082-1089 ◽

Cited By ~ 31

Author(s):

Todd J Schwedt ◽

Robert W Gereau ◽

Karen Frey ◽

Evan D Kharasch

Keyword(s):

Risk Factors ◽

Intracranial Aneurysms ◽

Prospective Observational Study ◽

Prospective Analysis ◽

Headache Frequency ◽

Factors Associated ◽

Aneurysm Treatment ◽

Unruptured Intracranial Aneurysms ◽

Potential Risk Factors ◽

Aneurysm Coiling

Objective: To analyze headache patterns prior to and following treatment of unruptured intracranial aneurysms and identify factors associated with different headache outcomes. Methods: A prospective observational study of patients being treated for unruptured intracranial aneurysms. Headache patterns were established prior to aneurysm treatment and for 6 months following treatment. Factors associated with different headache outcomes were investigated. Results: In all patients ( n = 44), 90-day headache frequency decreased from an average of 31 days prior to aneurysm treatment to 17 days following treatment ( p < 0.001). In patients with active pretreatment headaches ( n = 28), 90-day headache frequency decreased from 49 days to 26 days ( p = 0.002). Headache frequency was reduced in 68% of patients, while 9% of patients had new or worsened headaches following aneurysm treatment. Pretreatment migraine, more severe pretreatment headaches, higher pretreatment trait anxiety, and stent-assisted aneurysm coiling were associated with a lack of headache improvement. Conclusions: The majority of patients with headaches at the time of aneurysm treatment had reductions in headache frequency during the 6 months following treatment. Potential risk factors for poor headache outcomes were identified but need to be studied further.

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

Journal of Neurosurgery ◽

10.3171/jns.2000.93.3.0379 ◽

2000 ◽

Vol 93 (3) ◽

pp. 379-387 ◽

Cited By ~ 410

Author(s):

Seppo Juvela ◽

Matti Porras ◽

Kristiina Poussa

Keyword(s):

Risk Factors ◽

Smoking Status ◽

Significant Risk ◽

Significant Risk Factor ◽

Aneurysm Rupture ◽

Content Type ◽

Unruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

History Of ◽

Fine Print

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.

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