Aneurysm Morphology and Prediction of Rupture: An International Study of Unruptured Intracranial Aneurysms Analysis

Abstract BACKGROUND There are conflicting data between natural history studies suggesting a very low risk of rupture for small, unruptured intracranial aneurysms and retrospective studies that have identified a much higher frequency of small, ruptured aneurysms than expected. OBJECTIVE To use the prospective International Study of Unruptured Intracranial Aneurysms cohort to identify morphological characteristics predictive of unruptured intracranial aneurysm rupture. METHODS A case-control design was used to analyze morphological characteristics associated with aneurysm rupture in the International Study of Unruptured Intracranial Aneurysms database. Fifty-seven patients with ruptured aneurysms during follow-up were matched (by size and location) with 198 patients with unruptured intracranial aneurysms without rupture during follow-up. Twelve morphological metrics were measured from cerebral angiograms in a blinded fashion. RESULTS Perpendicular height (P = .008) and size ratio (ratio of maximum diameter to the parent vessel diameter; P = .01) were predictors of aneurysm rupture on univariate analysis. Aspect ratio, daughter sacs, multiple lobes, aneurysm angle, neck diameter, parent vessel diameter, and calculated aneurysm volume were not statistically significant predictors of rupture. On multivariate analysis, perpendicular height was the only significant predictor of rupture (Chi-square 7.1, P-value .008). CONCLUSION This study underscores the importance of other morphological factors, such as perpendicular height and size ratio, that may influence unruptured intracranial aneurysm rupture risk in addition to greatest diameter and anterior vs posterior location.

Download Full-text

Residuals, recurrences and re-treatment after endovascular repair of intracranial aneurysms: A retrospective methodological comparison

Interventional Neuroradiology ◽

10.1177/1591019919867841 ◽

2019 ◽

Vol 26 (1) ◽

pp. 45-54 ◽

Cited By ~ 3

Author(s):

Jens J Froelich ◽

Nicholas Cheung ◽

Johan AB de Lange ◽

Jessica Monkhorst ◽

Michael W Carr ◽

...

Keyword(s):

Endovascular Treatment ◽

Medical Records ◽

Intracranial Aneurysms ◽

Aneurysm Rupture ◽

Flow Diversion ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

Methodological Comparison

Objective Incomplete aneurysm occlusions and re-treatment rates of 52 and 10–30%, respectively, have been reported following endovascular treatment of intracranial aneurysms, raising clinical concerns regarding procedural efficacy. We compare residual, recurrence and re-treatment rates subject to different endovascular techniques in both ruptured and unruptured intracranial aneurysms at a comprehensive state-wide tertiary neurovascular centre in Australia. Methods Medical records, procedural and follow-up imaging studies of all patients who underwent endovascular treatment for intracranial aneurysms between July 2010 and July 2017 were reviewed retrospectively. Residuals, recurrences and re-treatment rates were assessed regarding initial aneurysm rupture status and applied endovascular technique: primary coiling, balloon- and stent-assisted coiling and flow diversion. Results Among 233 aneurysms, residual, recurrence and re-treatment rates were 27, 11.2 and 9.4%, respectively. Compared with unruptured aneurysms, similar residual and recurrence (p > .05), but higher re-treatment rates (4.5% vs. 19%; p < .001) were found for ruptured aneurysms. Residual, recurrence and re-treatment rates were: 13.3, 16 and 12% for primary coiling; 12, 12 and 10.7% for balloon-assisted coiling; 14.9, 7.5 and 4.5% for stent-assisted coiling; 91.9, 0 and 5.4% for flow diversion. Stent-assistance and flow-diversion were associated with lower recurrence and re-treatment rates, when compared with primary- and balloon-assisted coiling (p < .05). Conclusions Residuals and recurrences after endovascular treatment of intracranial aneurysms are less common than previously reported. Stent assistance and flow diversion seem associated with reduced recurrence- and re-treatment rates, when compared with primary- and balloon-assisted coiling. Restrained use of stents in ruptured aneurysms may be a contributing factor for higher recurrence/retreatment rates compared to unruptured aneurysms.

Download Full-text

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.

Download Full-text

LVIS Jr. stent for treatment of intracranial aneurysms with parent vessel diameter of 2.5 mm or less

Interventional Neuroradiology ◽

10.1177/1591019918759307 ◽

2018 ◽

Vol 24 (3) ◽

pp. 246-253 ◽

Cited By ~ 16

Author(s):

Alejandro Santillan ◽

Srikanth Boddu ◽

Justin Schwarz ◽

Ning Lin ◽

Y Pierre Gobin ◽

...

Keyword(s):

Intracranial Aneurysms ◽

Artery Aneurysm ◽

Vessel Diameter ◽

Aneurysm Rupture ◽

Anterior Communicating Artery ◽

Parent Vessel ◽

Low Profile ◽

Aneurysm Occlusion ◽

Middle Cerebral Artery Aneurysms

Background and purpose This retrospective study evaluates the safety, effectiveness, and long-term clinical and angiographic follow-up of intracranial aneurysms treated with the Low-Profile Visualized Intraluminal Support Junior (LVIS Jr.) stent and parent vessels of diameter equal to or less than 2.5 mm. Materials and methods We included all patients treated with the LVIS Jr. stent in aneurysms with small parent vessel diameter between March 2015 and July 2017. Periprocedural adverse events, immediate aneurysm occlusion rates, and clinical and angiographic follow-up are reported. Results A total of 35 patients with 35 aneurysms were included. Ten aneurysms were ruptured (28.6%) and 25 were unruptured (71.4%). The parent arteries measured 0.9 mm to 2.5 mm in diameter (mean, 2.2 mm). Intra-procedural thromboembolic complications occurred in four patients (11.4%) and there was an intraoperative aneurysm rupture in one patient (2.8%). Immediate complete aneurysm occlusion was noted in 21 out of 35 patients (60%). Clinical follow-up ranged between one and 25 months (mean, 10.5 months) and magnetic resonance angiography follow-up ranged between four and 24 months (mean, 10.4 months). Complete aneurysm occlusion was achieved in 21 out of 29 patients (72.4%) at last angiographic follow-up (mean, 9.4 months; range four to 23 months). In-stent stenosis occurred in one out of 29 patients (3.4%), who was asymptomatic. Of the four patients with in-stent thrombosis, three patients were treated with “Y configuration” (two patients with middle cerebral artery aneurysms and one patient with an anterior communicating artery aneurysm). Mortality rate was 0%. Neurological morbidity was 2.9%. Conclusions Stenting with the LVIS Jr. stent allowed us to treat complex intracranial aneurysms with parent vessel diameter of 2.5 mm or less with an acceptable safety profile.

Download Full-text

Management of Unruptured Intracranial Aneurysm in Japan

Medical Decision Making ◽

10.1177/0272989x9801800401 ◽

1998 ◽

Vol 18 (4) ◽

pp. 357-364 ◽

Cited By ~ 34

Author(s):

Noriaki Aoki ◽

Takao Kitahara ◽

Tsuguya Fukui ◽

J. Robert Beck ◽

Kazui Soma ◽

...

Keyword(s):

Clinical Trial ◽

Sensitivity Analysis ◽

Glasgow Outcome Scale ◽

Intracranial Aneurysms ◽

University Hospital ◽

Health Providers ◽

Unruptured Intracranial Aneurysm ◽

Unruptured Intracranial Aneurysms ◽

Quality Adjusted Life

The purpose of this study was to analyze the management of individual patients with unruptured intracranial aneurysms (UN-ANs) using a decision-analytic approach. Tran sition probabilities among Glasgow Outcome Scale (GOS) categories were estimated from the published literature and data from patients who had been treated at Kitasato University Hospital. Utilities were obtained from 140 health providers based principally on the GOS. Baseline analysis for a healthy 40-year-old man with an anterior UN-AN less than 10 mm in diameter showed that the quality-adjusted life expectancies for preventive operation and follow-up were 15.34 and 14.66 years, respectively. For a follow-up strategy to be preferred, the annual rupture rate had to be as low as 0.9%. These results were sustained through extensive sensitivity analysis. The results sup port preventive operation for UN-ANs, and identify problems that can be clarified with a well-designed stratified clinical trial. Key words: decision analysis; Markov model; unruptured intracranial aneurysms; Glasgow Outcome Scale; utility; preventive oper ations. (Med Decis Making 1998;18:357-364)

Download Full-text

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

Journal of Neurosurgery ◽

10.3171/jns/2008/108/5/1052 ◽

2008 ◽

Vol 108 (5) ◽

pp. 1052-1060 ◽

Cited By ~ 105

Author(s):

Seppo Juvela ◽

Matti Porras ◽

Kristiina Poussa

Keyword(s):

Risk Factors ◽

Intracranial Aneurysms ◽

Smoking Status ◽

Significant Risk ◽

Significant Risk Factor ◽

Aneurysm Rupture ◽

Unruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

History Of

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.

Download Full-text

Role of apoptosis in intracranial aneurysm rupture

Journal of Neurosurgery ◽

10.3171/jns.2004.101.6.1018 ◽

2004 ◽

Vol 101 (6) ◽

pp. 1018-1025 ◽

Cited By ~ 51

Author(s):

Luigi Pentimalli ◽

Andrea Modesti ◽

Andrea Vignati ◽

Enrico Marchese ◽

Alessio Albanese ◽

...

Keyword(s):

Intracranial Aneurysms ◽

Superficial Temporal Artery ◽

Aneurysm Rupture ◽

Terminal Deoxynucleotidyl Transferase ◽

Content Type ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Aneurysm Wall ◽

Unruptured Intracranial Aneurysms ◽

Fine Print

Object. Mechanisms involved in the rupture of intracranial aneurysms remain unclear, and the literature on apoptosis in these lesions is extremely limited. The hypothesis that apoptosis may reduce aneurysm wall resistance, thus contributing to its rupture, warrants investigation. The authors in this study focused on the comparative evaluation of apoptosis in ruptured and unruptured intracranial aneurysms. Peripheral arteries in patients harboring the aneurysms and in a group of controls were also analyzed. Methods. Between September 1999 and February 2002, specimens from 27 intracranial aneurysms were studied. In 13 of these patients apoptosis was also evaluated in specimens of the middle meningeal artery (MMA) and the superficial temporal artery (STA). The terminal deoxynucleotidyl transferase—mediated deoxyuridine triphosphate nick-end labeling technique was used to study apoptosis via optical microscopy; electron microscopy evaluation was performed as well. Apoptotic cell levels were related to patient age and sex, aneurysm volume and shape, and surgical timing. Significant differences in apoptosis were observed when comparing ruptured and unruptured aneurysms. High levels of apoptosis were found in 88% of ruptured aneurysms and in only 10% of unruptured lesions (p < 0.001). Elevated apoptosis levels were also detected in all MMA and STA specimens obtained in patients harboring ruptured aneurysms, whereas absent or very low apoptosis levels were observed in MMA and STA specimens from patients with unruptured aneurysms. A significant correlation between aneurysm shape and apoptosis was found. Conclusions. In this series, aneurysm rupture appeared to be more related to elevated apoptosis levels than to the volume of the aneurysm sac. Data in this study could open the field to investigations clarifying the causes of aneurysm enlargement and rupture.

Download Full-text

Intracranial Aneurysms: Does Size Really Matter?

Neurosurgery Open ◽

10.1093/neuopn/okaa015 ◽

2020 ◽

Vol 1 (4) ◽

Author(s):

Kashif Majeed ◽

Srikanth R Boddu ◽

Joseph Carnevale ◽

Elif Ezgi Cenberlitas ◽

Nicholas Williams ◽

...

Keyword(s):

Intracranial Aneurysms ◽

International Study ◽

Surgical Clipping ◽

Aneurysmal Rupture ◽

Ruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

Risk Of Rupture ◽

Brainstem Stroke ◽

Size Groups ◽

The Mean

Abstract BACKGROUND To stratify the risk of aneurysmal rupture, size remains the primary criterion as proposed by 2 ISUIA (International Study of Unruptured Intracranial Aneurysms) trials that recommend the observation of ≤7 mm aneurysms because of their low propensity to rupture. These recommendations are controversial, given the severe outcomes following hemorrhage. OBJECTIVE To retrospectively assess whether size correlates with aneurysmal rupture, and to analyze outcomes of endovascular and microsurgical procedures. METHODS All aneurysms presenting between 2016 and 2019 were reviewed. Age, gender, comorbidities, ruptured status, modes of treatment, and their outcomes were noted. Regression analysis was performed to correlate size with rupture. The type of intervention was based on clinical and aneurysmal characteristics and the likelihood of obliteration. RESULTS Of the 668 aneurysms, 116 had ruptured. In size groups 0 to 6 mm, 7 to 12 mm, 13 to 18 mm, 18 to 24 mm, and giant, the ruptured aneurysms were 60.3%, 30.2%, 1.7%, 0.9%, and 6.9%, respectively. The majority (423) were managed endovascularly, of which 84 (19.9%) were ruptured. A total of 97 (14.5%) underwent clipping, of which 31 were ruptured. The mean modified Rankin Scale for both treated groups was zero. One death in each group and a single brainstem stroke in the coiled group were noted. A total of 139 were followed, of which none had ruptured. The mean modified Raymond-Roy classification for endovascular therapy was 1.1, with 380 completely occluded; 15 had a score of 2, and 28 of score 3. CONCLUSION The ruptured aneurysms were mostly smaller than reported previously. Surgical clipping was at equipoise with endovascular treatments. Further studies to correlate aneurysmal characteristics to the risk of rupture are needed.

Download Full-text

Rupture immediately after growth of unruptured intracranial aneurysms during follow-up

Surgical Neurology International ◽

10.25259/sni_262_2019 ◽

2019 ◽

Vol 10 ◽

pp. 164

Author(s):

Taro Yanagawa ◽

Yoichi Harada ◽

Toru Hatayama ◽

Takuji Kono

Keyword(s):

Intracranial Aneurysms ◽

Internal Carotid ◽

Artery Aneurysm ◽

Resonance Imaging ◽

Middle Cerebral Artery Aneurysm ◽

Ruptured Aneurysms ◽

Unruptured Intracranial Aneurysms ◽

Risk Of Rupture ◽

Cerebral Artery Aneurysm

Background: The annual rupture rate of small unruptured intracranial aneurysms (UIAs) <5 mm is generally low; further, small UIAs are often treated conservatively. While the growth of aneurysms during follow-up is associated with a high risk of rupture, the urgency for surgical treatment of asymptomatic enlarged UIAs remains controversial. We experienced two patients in whom UIAs ruptured shortly after asymptomatic growth during follow-up. Case Description: A 1-mm right middle cerebral artery aneurysm was incidentally found in a 63-year-old woman. Preventive surgery was planned because the aneurysm grew rapidly; however, the aneurysm ruptured preoperatively. A 68-year-old woman had a small (4 mm) aneurysm at the left internal carotid-posterior communicating artery. The aneurysm grew rapidly after many years. Several hours after magnetic resonance imaging was performed, she presented to the hospital with loss of consciousness, and a diagnosis of subarachnoid hemorrhage due to the ruptured aneurysm was made. Conclusion: UIAs that rapidly increase during follow-up may be regarded as impending ruptured aneurysms.

Download Full-text

2D and 3D Morphologic Metrics Associated Intracranial Aneurysm Rupture

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19633 ◽

2010 ◽

Author(s):

Ding Ma ◽

Sabareesh K. Natarajan ◽

Jianping Xiang ◽

Adnan Siddiqui ◽

Elad I. Levy ◽

...

Keyword(s):

Image Segmentation ◽

Intracranial Aneurysms ◽

Vessel Diameter ◽

Aneurysm Rupture ◽

Size Ratio ◽

Patient Specific ◽

3D Image ◽

Parent Vessel ◽

3D Image Segmentation ◽

Aneurysm Size

Intracranial aneurysms (IAs) rupture results in severe morbidity and mortality. Therefore indentifying IA rupture risk is highly critical. Although it has been recognized that IA rupture is the result of a complex vascular degeneration process involving multiple mechanobiological factors, such information for each patient is not readily available in clinical setting. Alternatively, morphology and hemodynamic metrics can be derived from routine patient-specific imaging. In previous studies, a number of morphological metrics derived from analysis of reconstructed vascular 3D geometry have shown significance in discriminating ruptured from unruptued IAs, including in particular aneurysm size ratio, defined as IA size divided by the parent vessel diameter. However, these measures rely on 3D image segmentation and measurement, which makes them less practical in current angiographic rooms often equipped with only biplane angiogram capability and even when 3D rotational angiography is available, on-site 3D image segmentation and analyses are still not practical. Our foregoing study examined three parameters measured on 2D angiographs: aneurysm Size Ratio (SR), Aspect Ratio (AR) and Size. We found that SR had the strongest correlation with IA rupture. The current study further evaluates these geometric metrics, measured both from 3D and 2D images, with a larger cohort of saccular intracranial aneurysms.

Download Full-text

Early postmarket results with PulseRider for treatment of wide-necked intracranial aneurysms: a multicenter experience

Journal of Neurosurgery ◽

10.3171/2019.5.jns19313 ◽

2020 ◽

Vol 133 (6) ◽

pp. 1756-1765 ◽

Cited By ~ 1

Author(s):

Visish M. Srinivasan ◽

Aditya Srivatsan ◽

Alejandro M. Spiotta ◽

Benjamin K. Hendricks ◽

Andrew F. Ducruet ◽

...

Keyword(s):

Cerebral Artery ◽

Intracranial Aneurysms ◽

Aneurysm Rupture ◽

Anterior Communicating Artery ◽

Parent Vessel ◽

Aneurysm Neck ◽

Off Label ◽

Fda Approval ◽

Class 1

OBJECTIVETraditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device.METHODSThis study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications.RESULTSA total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a device-related intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2.CONCLUSIONSPulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

Download Full-text