Simulation of the natural history of cerebral aneurysms based on data from the International Study of Unruptured Intracranial Aneurysms

2006 ◽  
Vol 104 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Han Soo Chang
Keyword(s):  
Natural History ◽  
Intracranial Aneurysms ◽  
Cerebral Aneurysms ◽  
International Study ◽  
Medical Decision ◽  
Unruptured Aneurysms ◽  
Ruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Median Diameter ◽  
History Of

Object Despite recent publications of large-scale study data, controversy over the management of unruptured cerebral aneurysms continues. The low rupture rates in the International Study of Unruptured Intracranial Aneurysms (ISUIA) apparently contradicted surgeons’ experiences with ruptured aneurysms. In the present study, based on data from the ISUIA, a mathematical model describing the natural history of cerebral aneurysms was developed. With this model, the author aimed to examine the validity of data from the ISUIA and to provide a better treatment guideline for unruptured aneurysms. Methods The author made a computer simulation of the natural history of cerebral aneurysms that was used to calculate such figures as the prevalence of unruptured aneurysms, incidence of subarachnoid hemorrhage (SAH), and age and size distribution of both unruptured and ruptured aneurysms. The lifetime lesion rupture probability for individual patients with various ages and aneurysm sizes was also computed, thereby providing a useful index to help patients in the medical decision-making process. The computer model produced a sample of unruptured aneurysms in the general population with a prevalence of 4.2% and a median diameter of 5.8 mm. These unruptured aneurysms—affected by the rupture rate reported in the ISUIA—had a yearly SAH incidence of 19.6 per 100,000 persons. The median diameter of these aneurysms was 9.4 mm. Conclusions Findings in the present study validated the results of the ISUIA by showing that the seemingly low rupture rates could explain the statistical data for ruptured aneurysms. With the featured model, the author calculated the lifetime probability of lesion rupture—a useful measure for deciding on the optimal treatment for unruptured aneurysms.

Unruptured Intracranial Aneurysms and Multiple Aneurysms

2002 ◽  
Vol 15 (5) ◽  
pp. 589-596
Author(s):  
M. Fontanella ◽  
D. Garbossa ◽  
V. Luparello
Keyword(s):  
Natural History ◽  
Intracranial Aneurysms ◽  
Treatment Options ◽  
Clinical Status ◽  
International Study ◽  
Unruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
History Of ◽  
Risk Of Treatment

Surgery on unruptured intracranial aneurysms (UIAs) could be a good strategy for prevention of haemorrhage, but management decisions require an accurate assessment of the risks of various treatment options, compared with the natural history of subarachnoid haemorrhage (SAH). The International Study for Unruptured Aneurysms (ISUIA) showed that the natural history is different for patients with UIAs who have not experienced SAH, than it is for patients with a history of prior SAH due to a separate aneurysm, in whom the risk is increased. The size of the UIAs is the best predictor of future rupture and the site can also be. The role of elective neuroradiological screening is the subject of discussion. In fact, the possibility of treatment should be considered on the basis of the patient's age and clinical status. Factors that favour surgery include a young patient with a long life expectancy, previously ruptured aneurysms, a familiarity, large and symptomatic aneurysms and low risk of treatment. The role of endovascular treatment is also discussed.

Natural history and general management of unruptured intracranial aneurysms

2004 ◽  
Vol 17 (5) ◽  
pp. 1-6 ◽  
Author(s):  
Peng Roc Chen ◽  
Kai Frerichs ◽  
Robert Spetzler
Keyword(s):  
Natural History ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Cerebral Aneurysms ◽  
Population Based ◽  
Unruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
History Of ◽  
Unruptured Cerebral Aneurysms ◽  
Noninvasive Neuroimaging

After an aneurysmal subarachnoid hemorrhage, nearly half of the patients die and the half who survive suffer from irreversible cerebral damage. With increasing use of noninvasive neuroimaging techniques (for example, magnetic resonance and computerized tomography angiography), more unruptured cerebral aneurysms are found. To understand the prevalence of unruptured aneurysms in the general population, along with the risks of aneurysm formation, data on growth and rupture rates are crucial. The risk of rupture in aneurysms smaller than 10 mm is still not quite clear without a population-based prospective study. Nevertheless, a 0.5 to 2% annual risk may be a reasonable estimate. Growing aneurysms and those larger than 10 mm carry a higher rate of rupture. The management of an unruptured intracranial aneurysm should be based on a thorough understanding of the natural history of these lesions and careful evaluation of the morbidity and mortality levels associated with each treatment option.

scholarly journals Contemporary management of incidental intracranial aneurysms

2005 ◽  
Vol 18 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Ramachandra P. Tummala ◽  
Mustafa K. Bas ¸Kaya ◽  
Roberto C. Heros
Keyword(s):  
Natural History ◽  
Intracranial Aneurysms ◽  
Noninvasive Imaging ◽  
Attractive Alternative ◽  
Unruptured Aneurysms ◽  
Diagnosis And Management ◽  
Unruptured Intracranial Aneurysms ◽  
Incidental Aneurysms ◽  
History Of ◽  
Contemporary Management

The management of unruptured intracranial aneurysms has changed significantly in recent years and continues to evolve. The three main factors that have affected the management of unruptured intracranial aneurysms are as follows: 1) increased availability of noninvasive imaging technology, resulting in increased detection of incidental aneurysms; 2) improved understanding of the natural history of unruptured aneurysms; and 3) the advent of neuroendovascular therapy. In this report, the authors discuss the implications of these factors in the diagnosis and management of truly incidental, asymptomatic aneurysms and review the current practice patterns at their institution. Historical and current articles regarding noninvasive neuroimaging, aneurysm screening, endovascular and surgical therapy, and the natural history of unruptured aneurysms were reviewed. Current practices used for diagnosis and management of incidental aneurysms at the authors' institution were also reviewed. The management of incidental intracranial aneurysms has become an increasingly controversial subject in recent years. Improvements in noninvasive imaging resulting in detection of an increasing number of incidental aneurysms, the establishment of endovascular therapy as an attractive alternative to surgery, and studies indicating a more benign natural history for unruptured aneurysms than previously thought have led to significant changes in neurosurgical practice. Safety and long-term efficacy are the goals of treatment for unruptured aneurysms. Until conclusive studies are completed, the experience of the neurovascular team at each institution and the art of patient selection for treatment will continue to play a fundamental role in the management of these lesions.

Intrinsic, Transitional, and Extrinsic Morphological Factors Associated With Rupture of Intracranial Aneurysms

Neurosurgery ◽  
2015 ◽  
Vol 77 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Allen L. Ho ◽  
Ning Lin ◽  
Kai U. Frerichs ◽  
Rose Du
Keyword(s):  
Intracranial Aneurysms ◽  
Cerebral Aneurysms ◽  
Aneurysm Rupture ◽  
Extrinsic Factors ◽  
Flow Angle ◽  
Computed Tomographic ◽  
Ruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
History Of

Abstract BACKGROUND: As diagnosis and treatment of unruptured intracranial aneurysms continues to increase, management principles remain largely based on size. This is despite mounting evidence that aneurysm location and other morphologic variables could play a role in predicting overall risk of rupture. Morphological parameters can be divided into 3 main groups, those that are intrinsic to the aneurysm, those that are extrinsic to the aneurysm, and those that involve both the aneurysm and surrounding vasculature (transitional). OBJECTIVE: We present an evaluation of intrinsic, transitional, and extrinsic factors and their association with ruptured aneurysms. METHODS: Using preoperative computed tomographic angiography, we generated 3-dimensional models of aneurysms and their surrounding vasculature with Slicer software. Using univariate and multivariate analyses, we examined the association of intrinsic, transitional, and extrinsic aspects of aneurysm morphology with rupture. RESULTS: Between 2005 and 2013, 227 cerebral aneurysms in 4 locations were evaluated/treated at a single institution, and computed tomographic angiographies of 218 patients (97 unruptured and 130 ruptured) were analyzed. Ruptured aneurysms analyzed were associated with clinical factors of absence of multiple aneurysms and history of no prior rupture, and morphologic factors of greater aspect ratio. On multivariate analysis, aneurysm rupture remained associated with history of no prior rupture, greater flow angle, greater daughter-daughter vessel angle, and smaller parent-daughter vessel angle. CONCLUSION: By studying the morphology of aneurysms and their surrounding vasculature, we identified several parameters associated with ruptured aneurysms that include intrinsic, transitional, and extrinsic factors of cerebral aneurysms and their surrounding vasculature.

scholarly journals The natural history of unruptured intracranial aneurysms

2004 ◽  
Vol 17 (5) ◽  
pp. 1-5 ◽  
Author(s):  
J Mocco ◽  
Ricardo J. Komotar ◽  
Sean D. Lavine ◽  
Philip M. Meyers ◽  
E. Sander Connolly ◽  
...  
Keyword(s):  
Natural History ◽  
Intracranial Aneurysms ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
International Study ◽  
General Rule ◽  
Unruptured Intracranial Aneurysm ◽  
Risk Of Bleeding ◽  
Unruptured Intracranial Aneurysms ◽  
Risk Of Rupture ◽  
History Of

Since the publication of preliminary results from the International Study of Unruptured Intracranial Aneurysms in 1998 there has been a great deal of debate concerning the natural history of these lesions and their attendant risk of aneurysmal subarachnoid hemorrhage. Therefore, the authors reviewed a selected number of crucial studies concerning this topic to determine the best evidence-based estimate of a rupture rate for these lesions. Based on this analysis, the yearly risk of bleeding for an unruptured intracranial aneurysm is estimated to be approximately 1% for aneurysms 7 to 10 mm in diameter. This risk of rupture increases with aneurysm size and it likewise diminishes as the size of the lesion decreases. This general rule serves as a reasonable interpretation of the results reported in the current body of literature.

A mathematical model of the natural history of intracranial aneurysms: quantification of the benefit of prophylactic treatment

2006 ◽  
Vol 104 (2) ◽  
pp. 195-200 ◽  
Author(s):  
Yuhei Yoshimoto
Keyword(s):  
Mathematical Model ◽  
Natural History ◽  
Intracranial Aneurysms ◽  
Prophylactic Treatment ◽  
De Novo ◽  
Epidemiological Data ◽  
Unruptured Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
Life Years ◽  
History Of

Object The International Study of Unruptured Intracranial Aneurysms (ISUIA) data raised new controversy regarding the threshold size that requires treatment. In particular, this study has been criticized for disagreeing with previous epidemiological data. Methods The author first used a Markov model to simulate the natural history of intracranial aneurysms, making three key assumptions based on prospective ISUIA data and other recent reports: that the rate of de novo aneurysm formation is constant after the age of 20 years; that unruptured aneurysms gain volume at a constant rate; and that unruptured aneurysms rupture at a volume-dependent rate. Next, he expressed outcomes for patients with unruptured aneurysms in terms of expected number of quality-adjusted life years (QALY) and compared two hypothetical cohorts, one receiving treatment and the other not being treated. These assumptions enabled the construction of a mathematical model with epidemiologically compatible findings. The benefits of treatment for unruptured aneurysms were highly influenced by aneurysm size and were calculated as −0.28, 0.25, and 1.07 QALY for patients having unruptured aneurysms with diameters of 7, 10, and 13 mm, respectively. Conclusions Under the author’s assumptions, the prospective ISUIA data may be consistent with epidemiological findings. Prophylactic treatment for unruptured aneurysms may produce some benefits in large aneurysms if acceptable treatment risks can be assured, but it is not likely to offer improvement over the natural history for patients with small aneurysms.

Natural history of unruptured intracranial aneurysms

2004 ◽  
Vol 17 (5) ◽  
pp. 1-5 ◽  
Author(s):  
Robert D. Ecker ◽  
L. Nelson Hopkins
Keyword(s):  
Natural History ◽  
Aspect Ratio ◽  
Intracranial Aneurysm ◽  
Intracranial Aneurysms ◽  
International Study ◽  
Prospective Data ◽  
Initial Decision ◽  
Unruptured Intracranial Aneurysms ◽  
History Of ◽  
Benign Course

Since the publication of the retrospective part of the International Study of Unruptured Intracranial Aneurysms (ISUIA) in 1998, there has been a significant focus in the neurosurgical literature on the natural history of these lesions. The prospective data from the second part of the ISUIA, which was published in 2003, provided further evidence that small, asymptomatic intracranial aneurysms may have a more benign course than previously believed. With the data from the ISUIA as a reference point, in this paper the authors strive to provide a source of practical clinical data to aid cerebrovascular physicians in the initial decision to treat or observe a patient with a small, asymptomatic intracranial aneurysm. The issues covered will include previous rupture, symptoms other than rupture, aneurysm size, site, and aspect ratio. It is the authors' goal to provide a useful practical framework on the relevant clinical issues as an aid to practitioners treating patients who present with intracranial aneurysms.

Unruptured intracranial aneurysms in children: 18 years’ experience in a tertiary care pediatric institution

2019 ◽  
Vol 24 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Daniel-Alexandre Bisson ◽  
Peter Dirks ◽  
Afsaneh Amirabadi ◽  
Manohar M. Shroff ◽  
Timo Krings ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Natural History ◽  
Internal Carotid Artery ◽  
Intracranial Aneurysms ◽  
Internal Carotid ◽  
Tertiary Care ◽  
Unruptured Intracranial Aneurysms ◽  
History Of ◽  
Mean Size

OBJECTIVEThere are little data in the literature on the characteristics and natural history of unruptured intracranial aneurysms in children. The authors analyzed their experience with unruptured intracranial aneurysms in the pediatric population at their tertiary care pediatric institution over the last 18 years. The first objective was to assess the imaging characteristics and natural history of these aneurysms in order to help guide management strategies in the future. A second objective was to evaluate the frequency of an underlying condition when an incidental intracranial aneurysm was detected in a child.METHODSThe authors conducted a Research Ethics Board–approved retrospective review of incidental intracranial aneurysms in patients younger than 18 years of age who had been treated at their institution in the period from 1998 to 2016. Clinical (age, sex, syndrome) and radiological (aneurysm location, type, size, thrombus, mass effect) data were recorded. Follow-up imaging was assessed for temporal changes.RESULTSSixty intracranial aneurysms occurred in 51 patients (36 males, 15 females) with a mean age of 10.5 ± 0.5 years (range 9 months–17 years). Forty-five patients (88.2%) had a single aneurysm, while 2 and 3 aneurysms were found in 3 patients each (5.8%). Syndromic association was found in 22 patients (43.1%), most frequently sickle cell disease (10/22 [45.5%]). Aneurysms were saccular in 43 cases (71.7%; mean size 5.0 ± 5.7 mm) and fusiform in the remaining 17 (28.3%; mean size 6.5 ± 2.7 mm). Thirty-one aneurysms (51.7%) arose from the internal carotid artery (right/left 1.4), most commonly in the cavernous segment (10/31 [32.3%]). Mean size change over the entire follow-up of 109 patient-years was a decrease of 0.6 ± 4.2 mm (range −30.0 to +4.0 mm, rate −0.12 ± 9.9 mm/yr). Interval growth (2.0 ± 1.0 mm) was seen in 8 aneurysms (13.3%; 4 saccular, 4 fusiform). An interval decrease in size (8.3 ± 10.7 mm) was seen in 6 aneurysms (10%). There was an inverse relationship between aneurysm size and growth rate (r = −0.82, p < 0.00001). One aneurysm was treated endovascularly with internal carotid artery sacrifice.CONCLUSIONSUnruptured pediatric intracranial aneurysms are most frequently single but can occur in multiples in a syndromic setting. None of the cases from the study period showed clinical or imaging signs of rupture. Growth over time, although unusual and slow, can occur in a proportion of these patients, who should be identified for short-term imaging surveillance.

scholarly journals Natural History of Unruptured Intracranial Aneurysms

2018 ◽  
Vol 27 (3) ◽  
pp. 184-191
Author(s):  
Jun C. Takahashi ◽  
Hiroharu Kataoka ◽  
Tetsu Satow ◽  
Hisae Mori
Keyword(s):  
Natural History ◽  
Intracranial Aneurysms ◽  
Unruptured Intracranial Aneurysms ◽  
History Of
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