Is the Aspect Ratio a Reliable Index for Predicting the Rupture of a Saccular Aneurysm?

Abstract OBJECTIVE The present retrospective study was undertaken to prove the reliability of the aspect ratio (aneurysm depth to aneurysm neck width) for predicting an aneurysmal rupture. The aspect ratio is considered a better geometric index than aneurysm size for determining the intra-aneurysmal blood flow. METHODS We measured the aspect ratios and the sizes of aneurysms, as determined by examining angiographic films magnified 1.4×, in 129 patients with ruptured aneurysms and in 72 patients with 78 unruptured aneurysms. After categorizing the aneurysms into four groups on the basis of their locations (aneurysms of the anterior communicating artery, middle cerebral artery, internal carotid artery-posterior communicating artery [ICA-PComA], and other aneurysms), a statistical analysis of ruptured and unruptured aneurysms was performed. RESULTS The mean aneurysm size was found to be statistically significant in the aneurysms at the ICA-PComA and in locations excluding the anterior communicating artery, the middle cerebral artery, and the ICA-PComA. However, the mean aspect ratio was statistically significant at all four locations. In patients with ruptured aneurysms, no ruptured aneurysms with an aspect ratio of less than 1.0 were found. The distribution of the ruptured group versus the unruptured group with an aspect ratio of less than 1.6 at each location was 13 versus 79%, respectively, at the anterior communicating artery, 11 versus 58% at the middle cerebral artery, 11% versus 85% at the ICA-PComA, and 7 versus 81% at other locations. CONCLUSION The aspect ratio between ruptured aneurysms and unruptured aneurysms was found to be statistically significant, and almost 80% of the ruptured aneurysms showed an aspect ratio of more than 1.6, whereas almost 90% of the unruptured aneurysms showed an aspect ratio of less than 1.6. This study therefore suggests that the aspect ratio may be useful in predicting imminent aneurysmal ruptures.

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Differences in simple morphological variables in ruptured and unruptured middle cerebral artery aneurysms

Journal of Neurosurgery ◽

10.3171/2012.7.jns111766 ◽

2012 ◽

Vol 117 (5) ◽

pp. 913-919 ◽

Cited By ~ 53

Author(s):

Ning Lin ◽

Allen Ho ◽

Bradley A. Gross ◽

Steven Pieper ◽

Kai U. Frerichs ◽

...

Keyword(s):

Aspect Ratio ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Aneurysm Rupture ◽

Morphological Parameters ◽

Flow Angle ◽

Ruptured Aneurysms ◽

Aneurysm Size ◽

Unruptured Intracranial Aneurysms ◽

Morphological Variables

Object Management of unruptured intracranial aneurysms remains controversial in neurosurgery. The contribution of morphological parameters has not been included in the treatment paradigm in a systematic manner or for any particular aneurysm location. The authors present a large sample of middle cerebral artery (MCA) aneurysms that were assessed using morphological variables to determine the parameters associated with aneurysm rupture. Methods Preoperative CT angiography (CTA) studies were evaluated using Slicer software to generate 3D models of the aneurysms and their surrounding vascular architecture. Morphological parameters examined in each model included 5 variables already defined in the literature (aneurysm size, aspect ratio, aneurysm angle, vessel angle, and size ratio) and 3 novel variables (flow angle, distance to the genu, and parent-daughter angle). Univariate and multivariate statistical analyses were performed to determine statistical significance. Results Between 2005 and 2008, 132 MCA aneurysms were treated at a single institution, and CTA studies of 79 aneurysms (40 ruptured and 39 unruptured) were analyzed. Fifty-three aneurysms were excluded because of reoperation (4), associated AVM (2), or lack of preoperative CTA studies (47). Ruptured aneurysms were associated with larger size, greater aspect ratio, larger aneurysm and flow angles, and smaller parent-daughter angle. Multivariate logistic regression revealed that aspect ratio, flow angle, and parent-daughter angle were the strongest factors associated with ruptured aneurysms. Conclusions Aspect ratio, flow angle, and parent-daughter angle are more strongly associated with ruptured MCA aneurysms than size. The association of parameters independent of aneurysm morphology with ruptured aneurysms suggests that these parameters may be associated with an increased risk of aneurysm rupture. These factors are readily applied in clinical practice and should be considered in addition to aneurysm size when assessing the risk of aneurysm rupture specific to the MCA location.

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Sizes of ruptured and unruptured aneurysms in relation to their sites and the ages of patients

Journal of Neurosurgery ◽

10.3171/jns.2002.96.1.0064 ◽

2002 ◽

Vol 96 (1) ◽

pp. 64-70 ◽

Cited By ~ 162

Author(s):

Bryce Weir ◽

Lew Disney ◽

Theodore Karrison

Keyword(s):

Cerebral Artery ◽

Patient Age ◽

Content Type ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Patient Âgé ◽

Risk Of Rupture ◽

Mean Size ◽

The Mean ◽

Fine Print

Object. The authors explore the risk of rupture in aneurysms categorized by size. Methods. A computerized database of 945 patients with aneurysms treated between 1967 and 1987 was retrospectively established. All available clinical and radiological studies were abstracted. Because of the recent interest in the size of intracranial aneurysms in relation to their likelihood of rupture, the database was searched with respect to this parameter. In 390 patients representing 41% of all cases, aneurysms were measured by neuroradiologists at the time of diagnosis. In 78% of the 945 patients there was only one aneurysm, and of the 507 aneurysms that were measured, 60% were solitary. Of all patients, 86% had ruptured aneurysms. The average age of all patients was 47 years, and for those with ruptured aneurysms it was 46 years. Of the ruptured aneurysms, 77% were 10 mm or smaller, compared with 85% of the unruptured aneurysms. It was found that 40.3% of the ruptured aneurysms were on the anterior cerebral artery or anterior communicating artery, compared with 13% of the unruptured aneurysms. None of the cavernous internal carotid artery (ICA) aneurysms were ruptured and 65% of the ophthalmic artery (OphA) aneurysms were. Of the unruptured aneurysms, 15% were located in the cavernous ICA or the OphA. Of the ruptured aneurysms, 29% were on the middle cerebral artery, compared with 36% of the unruptured aneurysms. The mean size of ruptured and unruptured aneurysms showed no statistically significant increase with patient age, although the difference in size between the ruptured and unruptured aneurysms decreased with increasing age. The mean size of all ruptured aneurysms (10.8 mm) was significantly larger than the mean size of all unruptured aneurysms (7.8 mm, p < 0.001); the median sizes were 10 mm and 5 mm, respectively. The size of ruptured aneurysms in patients who died in the hospital was significantly larger than those in the patients who survived (12 mm compared with 9.9 mm, p = 0.004). Symptomatic unruptured aneurysms were significantly larger than incidental unruptured aneurysms (14.6 mm compared with 6.9 mm, p = 0.032), which were, in turn, larger than aneurysms that were unruptured and part of a multiple aneurysm constellation. Both ruptured and unruptured aneurysms were larger in male than in female patients, but not significantly. Conclusions. Site and patient age, as well as lesion size, may affect the chance of rupture.

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Statistical wall shear stress maps of ruptured and unruptured middle cerebral artery aneurysms

Journal of The Royal Society Interface ◽

10.1098/rsif.2011.0490 ◽

2011 ◽

Vol 9 (69) ◽

pp. 677-688 ◽

Cited By ~ 37

Author(s):

L. Goubergrits ◽

J. Schaller ◽

U. Kertzscher ◽

N. van den Bruck ◽

K. Poethkow ◽

...

Keyword(s):

Shear Stress ◽

Wall Shear Stress ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

Dimensional Space ◽

Neck Region ◽

Spherical Shape ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Wall Shear

Haemodynamics and morphology play an important role in the genesis, growth and rupture of cerebral aneurysms. The goal of this study was to generate and analyse statistical wall shear stress (WSS) distributions and shapes in middle cerebral artery (MCA) saccular aneurysms. Unsteady flow was simulated in seven ruptured and 15 unruptured MCA aneurysms. In order to compare these results, all geometries must be brought in a uniform coordinate system. For this, aneurysms with corresponding WSS data were transformed into a uniform spherical shape; then, all geometries were uniformly aligned in three-dimensional space. Subsequently, we compared statistical WSS maps and surfaces of ruptured and unruptured aneurysms. No significant ( p > 0.05) differences exist between ruptured and unruptured aneurysms regarding radius and mean WSS. In unruptured aneurysms, statistical WSS map relates regions with high (greater than 3 Pa) WSS to the neck region. In ruptured aneurysms, additional areas with high WSS contiguous to regions of low (less than 1 Pa) WSS are found in the dome region. In ruptured aneurysms, we found significantly lower WSS. The averaged aneurysm surface of unruptured aneurysms is round shaped, whereas the averaged surface of ruptured cases is multi-lobular. Our results confirm the hypothesis of low WSS and irregular shape as the essential rupture risk parameters.

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ANEURYSMS OF THE DISTAL ANTERIORCEREBRAL ARTERY

Neurosurgery ◽

10.1227/01.neu.0000249267.33945.e7 ◽

2007 ◽

Vol 60 (2) ◽

pp. 227-234 ◽

Cited By ~ 35

Author(s):

David A. Steven ◽

Stephen P. Lownie ◽

Gary G. Ferguson

Keyword(s):

Cerebral Artery ◽

Endovascular Coiling ◽

Anterior Circulation ◽

Operative Morbidity ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Grade Ii ◽

The Mean ◽

Distal Anterior Cerebral Artery ◽

Anterior Circulation Aneurysms

Abstract OBJECTIVE The aim of this study was to present the clinical and radiological characteristics, surgical management, and outcome in a large series of patients with aneurysms of the distal anterior cerebral artery (DACA) managed in the microsurgical era. METHODS The records of 1109 patients with anterior circulation aneurysms managed at the authors' institution between 1970 and 1998 were reviewed. RESULTS Fifty-nine patients (5.3%) were identified with 67 DACA aneurysms. Seventy-three percent of the patients were women. The mean age of all patients was 47 years. Multiple aneurysms were identified in 51% of all patients, most commonly on the middle cerebral artery. Thirty-six patients had ruptured DACA aneurysms and 23 had unruptured aneurysms. In those with ruptured aneurysms, the admission grade was Grade I in 10 patients (27.8%), Grade II in three patients (8.3%), Grade III in 10 patients (27.8%), Grade IV in seven patients (19.4%), and Grade V in six patients (16.7%). Frontal lobe hematomas occurred in 28% of the patients with ruptured aneurysms and carried a poor prognosis. In those with unruptured aneurysms, 11 were incidental and 12 were identified after a subarachnoid hemorrhage from another aneurysm. The mean diameter was 10 mm in ruptured aneurysms and 5.8 mm in unruptured aneurysms. Fifty-eight patients underwent surgery and one patient was treated with endovascular coiling. Six patients, all with ruptured aneurysms, died. Seventy percent of survivors with ruptured aneurysms had a favorable outcome. CONCLUSION DACA aneurysms possess a number of characteristics that distinguish them from the more common intracranial aneurysms. With modern neurosurgical and endovascular techniques, an acceptable operative morbidity and mortality can be achieved.

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Characteristics of Unruptured Compared to Ruptured Intracranial Aneurysms: A Multicenter Case–Control Study

Neurosurgery ◽

10.1093/neuros/nyx365 ◽

2017 ◽

Vol 83 (1) ◽

pp. 43-52 ◽

Cited By ~ 10

Author(s):

Isabel C Hostettler ◽

Varinder S Alg ◽

Nichole Shahi ◽

Fatima Jichi ◽

Stephen Bonner ◽

...

Keyword(s):

Subarachnoid Hemorrhage ◽

Cerebral Artery ◽

Intracranial Aneurysms ◽

Aneurysmal Subarachnoid Hemorrhage ◽

Anterior Communicating Artery ◽

Imaging Data ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Multivariable Analyses ◽

Different Characteristics

Abstract BACKGROUND Only a minority of intracranial aneurysms rupture to cause subarachnoid hemorrhage. OBJECTIVE To test the hypothesis that unruptured aneurysms have different characteristics and risk factor profiles compared to ruptured aneurysms. METHODS We recruited patients with unruptured aneurysms or aneurysmal subarachnoid hemorrhages at 22 UK hospitals between 2011 and 2014. Demographic, clinical, and imaging data were collected using standardized case report forms. We compared risk factors using multivariable logistic regression. RESULTS A total of 2334 patients (1729 with aneurysmal subarachnoid hemorrhage, 605 with unruptured aneurysms) were included (mean age 54.22 yr). In multivariable analyses, the following variables were independently associated with rupture status: black ethnicity (odds ratio [OR] 2.42; 95% confidence interval [CI] 1.29-4.56, compared to white) and aneurysm location (anterior cerebral artery/anterior communicating artery [OR 3.21; 95% CI 2.34-4.40], posterior communicating artery [OR 3.92; 95% CI 2.67-5.74], or posterior circulation [OR 3.12; 95% CI 2.08-4.70], compared to middle cerebral artery). The following variables were inversely associated with rupture status: antihypertensive medication (OR 0.65; 95% CI 0.49-0.84), hypercholesterolemia (0.64 OR; 95% CI 0.48-0.85), aspirin use (OR 0.28; 95% CI 0.20-0.40), internal carotid artery location (OR 0.53; 95% CI 0.38-0.75), and aneurysm size (per mm increase; OR 0.76; 95% CI 0.69-0.84). CONCLUSION We show substantial differences in patient and aneurysm characteristics between ruptured and unruptured aneurysms. These findings support the hypothesis that different pathological mechanisms are involved in the formation of ruptured aneurysms and incidentally detected unruptured aneurysms. The potential protective effect of aspirin might justify randomized prevention trials in patients with unruptured aneurysms.

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Temporary occlusion of the middle cerebral artery in intracranial aneurysm surgery: time limitation and advantage of brain protection

Neurosurgical FOCUS ◽

10.3171/foc.1997.2.6.7 ◽

1997 ◽

Vol 2 (6) ◽

pp. E6 ◽

Cited By ~ 3

Author(s):

Sean D. Lavine ◽

Lena S. Masri ◽

Michael L. Levy ◽

Steven L. Giannotta

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Group Versus ◽

Arterial Occlusion ◽

Brain Protection ◽

Multiple Aneurysms ◽

Increased Risk ◽

Temporary Occlusion ◽

The Mean ◽

Mca Aneurysm

The risk of focal infarction secondary to the induced reversible arrest of local arterial flow during microsurgical dissection of middle cerebral artery (MCA) aneurysms was evaluated further to define the optimal approach to temporary arterial occlusion. To compare the effectiveness of brain-protection anesthetics, a group of patients treated with the intravenous agents, propofol, etomidate, and pentobarbital, administered individually or in combination, was compared to a group treated with the inhalational agent isoflurane. Forty-nine consecutive MCA aneurysm surgeries involving the temporary clipping of the parent vessel were retrospectively reviewed. Thirty-eight patients received intravenous brain-protection (IVBP) anesthesia. Groups of patients with and without infarctions, and receiving and not receiving IVBP, were compared based on the duration and nature of temporary arterial occlusion. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The overall infarction rate was 22.4% (11 of 49 patients), including 15.8% (six of 38 patients) in the IVBP group versus 45.5% (five of 11 patients) in the isoflurane (ISO) group. In the ISO group, the mean duration of temporary occlusion was 3.9 ± 2.2 minutes for patients without infarction versus 12.2 ± 4.3 minutes for patients with focal infarction (p < 0.01). In contrast, the mean duration was 13.6 ± 10.6 minutes for patients without infarction and 18.5 ± 9.9 minutes for patients with infarction in the IVBP group. All patients in the ISO group who underwent occlusion lasting 10 minutes or longer suffered an infarction versus five of 23 patients in the IVBP group. Patients with multiple aneurysms were found to be at increased risk of developing focal infarction, whereas those treated with intermittent temporary clip application were at a decreased risk. It is concluded that patients in whom focal iatrogenic ischemia is induced during MCA aneurysm clip ligation have a significant advantage compared with those receiving ISO when they are given pentobarbital as the primary neuroprotective agent or when they receive propofol or etomidate titrated to achieve electroencephalographic burst suppression, particularly if more than 10 minutes of occlusion time is required. It is also concluded that 10 minutes is a general guideline for safe, temporary occlusion of the MCA. The use of intermittent temporary arterial occlusion and patients with multiple aneurysms need further evaluation before specific recommendations can be made.

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Current Management of Middle Cerebral Artery Aneurysms

Neurosurgery ◽

10.1227/neu.0b013e3182804aa2 ◽

2012 ◽

Vol 72 (3) ◽

pp. 415-427 ◽

Cited By ~ 95

Author(s):

Ana Rodríguez-Hernández ◽

Michael E. Sughrue ◽

Sina Akhavan ◽

Julian Habdank-Kolaczkowski ◽

Michael T. Lawton

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Endovascular Therapy ◽

Morbidity Rate ◽

Surgical Morbidity ◽

Unruptured Aneurysms ◽

Poor Grade ◽

Ruptured Aneurysms ◽

Radiology Service ◽

First Choice

Abstract BACKGROUND: One response to randomized trials like the International Subarachnoid Aneurysm Trial has been to adopt a “coil first” policy, whereby all aneurysms be considered for coiling, reserving surgery for unfavorable aneurysms or failed attempts. Surgical results with middle cerebral artery (MCA) aneurysms have been excellent, raising debate about the respective roles of surgical and endovascular therapy. OBJECTIVE: To review our experience with MCA aneurysms managed with microsurgery as the treatment of first choice. METHODS: Five hundred forty-three patients with 631 MCA aneurysms were managed with a “clip first” policy, with 115 patients (21.2%) referred from the Neurointerventional Radiology service and none referred from the Neurosurgical service for endovascular management. RESULTS: Two hundred eighty-two patients (51.9%) had ruptured aneurysms and 261 (48.1%) had unruptured aneurysms. MCA aneurysms were treated with clipping (88.6%), thrombectomy/clip reconstruction (6.2%), and bypass/aneurysm occlusion (3.3%). Complete aneurysm obliteration was achieved with 620 MCA aneurysms (98.3%); 89.7% of patients were improved or unchanged after therapy, with a mortality rate of 5.3% and a permanent morbidity rate of 4.6%. Good outcomes were observed in 92.0% of patients with unruptured and 70.2% with ruptured aneurysms. Worse outcomes were associated with rupture (P = .04), poor grade (P = .001), giant size (P = .03), and hemicraniectomy (P < .001). CONCLUSION: At present, surgery should remain the treatment of choice for MCA aneurysms. Surgical morbidity was low, and poor outcomes were due to an inclusive policy that aggressively managed poor-grade patients and complex aneurysms. This experience sets a benchmark that endovascular results should match before considering endovascular therapy an alternative for MCA aneurysms.

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Coiling and clipping of middle cerebral artery aneurysms: a systematic review on clinical and imaging outcome

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2014-011478 ◽

2014 ◽

Vol 8 (1) ◽

pp. 24-29 ◽

Cited By ~ 13

Author(s):

IJsbrand A Zijlstra ◽

Dagmar Verbaan ◽

Charles B Majoie ◽

Peter Vandertop ◽

Rene van den Berg

Keyword(s):

Middle Cerebral Artery ◽

Cerebral Artery ◽

Mortality And Morbidity ◽

Unruptured Aneurysms ◽

Ruptured Aneurysms ◽

Morphological Aspects ◽

Standardized Reporting ◽

Aneurysm Occlusion ◽

Mca Aneurysm ◽

Middle Cerebral Artery Aneurysms

BackgroundThere is an ongoing debate on the preferred treatment of middle cerebral artery (MCA) aneurysms. The purpose of this study was to assess the clinical and imaging outcomes comparing conventional coiling and clipping of unruptured and ruptured MCA aneurysms.MethodsWe searched the electronic databases PubMed, EMBASE, and Cochrane from January 1990 to May 2014.Results51 studies were included in the analysis. Favorable outcome was reported in 97.0% and 77.1%, and in 97.2% and 72.8% of patients after coiling and clipping of unruptured and ruptured aneurysms, respectively. Death rates were 1.1% and 8.4% after coiling and 0.3% and 14.7% after clipping of unruptured and ruptured aneurysms, respectively. Initial adequate occlusion was obtained in 89.6% and 92.1% after coiling of unruptured and ruptured aneurysms, respectively. Only three studies on clipping reported on aneurysm occlusion during follow-up.ConclusionsBoth coiling and clipping are procedures with low mortality and morbidity rates and, although it may seem that coiling is better for ruptured aneurysms and clipping for unruptured aneurysms, no firm conclusions can be drawn due to the variation in study design and lack of standardized reporting on MCA aneurysm treatments. Standardized observational studies from prospectively kept databases are needed to allow stronger conclusions to be drawn on what is the best treatment for MCA aneurysms. Comparable with aneurysms in other locations, a multidisciplinary approach is therefore recommended with selection of treatment modality based on the clinical condition of the patient and the morphological aspects of the aneurysm.

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Aneurysm Arising at the Origin of a Duplicated Middle Cerebral Artery

Case Reports in Neurology ◽

10.1159/000517366 ◽

2021 ◽

pp. 446-450

Author(s):

Jean Roch Alliez ◽

Luis Manera

Keyword(s):

Computed Tomography ◽

Subarachnoid Haemorrhage ◽

Middle Cerebral Artery ◽

Cerebral Artery ◽

World Federation ◽

Treatment Procedure ◽

3D Computed Tomography ◽

Ruptured Aneurysms ◽

Tomography Reconstruction ◽

Computed Tomography Reconstruction

A duplicated middle cerebral artery (DMCA) is a common anomaly. However, aneurysms arising from the origin of a DMCA are extremely rare. A 22-year-old female was admitted to our hospital with a World Federation of Neurosurgical Societies grade 2 subarachnoid haemorrhage. Four-vessel angiography revealed a DMCA and an aneurysm arising from the origin of this artery. The aneurysm was successfully treated by embolization, and the patient was discharged 2 weeks later. Ruptured aneurysms arising from the origin of a DMCA can be successfully treated by embolization. These aneurysms are small and 3D-computed tomography reconstruction is mandatory to detect them. It is important to preserve the DMCA during the treatment procedure.

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