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

Department of Neurosurgery, and.
Journal of Neurosurgery (Impact Factor: 3.15). 09/2012; 117(5). DOI: 10.3171/2012.7.JNS111766
Source: PubMed

ABSTRACT 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.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives: We evaluated rupture risk of multiple cerebral aneurysms in aspects of various morphological parameters, and determined which parameter can be a reliable predictor as one aneurysm ruptured, and the others did not. Methods: Between 2007 and 2012, three-dimensional (3D) angiographic images of 85 patients harboring multiple aneurysms (85 ruptured and 104 unruptured aneurysms) were used to assess the following morphological parameters: geometry of the aneurysm itself, e.g. maximal size, aspect ratio, bottleneck ratio, height/width ratio, undulation, and daughter sac; architecture of the aneurysm and surrounding vessels, e.g. aneurysmal angle, vessel angle, inflow angle, parent-daughter angle, and size ratio type I & II. Univariate analysis was applied to all parameters, and significant parameters were identified in multivariate analysis, yielding the cut-off point from receiver-operating characteristic (ROC) curve analysis. Results: On multivariate logistic regression, the aspect ratio [odds ratio (OR), 1·21; 95% confidence interval (CI), 1·05-1·41] and daughter sac (OR, 3·12; 95% CI, 1·05-9·27) were significant parameters in geometries of the aneurysm itself. The size ratio type I (OR, 1·14; 95% CI, 1·05-1·22) and parent-daughter angle (OR, 1·02; 95% CI, 1·00-1·04) were independent parameters in architecture of the aneurysm and surrounding vessels. From the ROC curve, the aspect ratio and size ratio type I had cut-off values of 1·3 and 1·8, respectively. Conclusion: Several morphological parameters were investigated to predict a rupture in multiple cerebral aneurysms using 3D angiogram. The aspect ratio, size ratio type I, daughter sac, and parent-daughter angle were revealed as competent parameters.
    Neurological Research 05/2014; 36(12):1743132814Y0000000393. DOI:10.1179/1743132814Y.0000000393 · 1.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to derive a model describing the evolution of bifurcation type cerebral aneurysms based on morphological and hemodynamic parameters. Idealized bifurcation models were constructed based on the two morphological parameters of aspect ratio (AR) and size ratio (SR). Aneurysm development was investigated according to the following four patterns: R1, increasing SR with constant AR; R2, increasing AR with constant SR; R3, increasing SR and increasing AR; R4, increasing AR with constant parent artery diameter. Relationships were obtained between energy loss (EL) and morphological parameters (EL-SR and EL-AR curves). The curves were validated by mapping the growth of a ruptured patient-specific bifurcation aneurysm at three stages of follow-up. EL increased in parallel with growth patterns R1 and R3, whereas growth pattern R2 showed a decrease in EL. No significant changes were observed in EL when the growth of the aneurysm was associated only with changes in aneurysm size and independent of changes in parent artery diameter and main flow (R4). Changes in parent artery diameter of bifurcation aneurysms resulted in significant variation in EL. Mapping the growth of a follow-up aneurysm onto the EL-AR curve demonstrated that aneurysms with increasing EL during the observation period are at higher risk of rupture than aneurysms with decreasing EL. Based on the proposed growth model, assessment of morphological (AR and SR) and hemodynamic (EL) parameters may provide quantifiable information on the risk of bifurcation aneurysm rupture during clinical patient follow-up.
    Journal of Clinical Neuroscience 06/2014; 21(9). DOI:10.1016/j.jocn.2013.12.021 · 1.32 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Since the initial publication of the International Study of Unruptured Intracranial Aneurysms (ISUIA), management of unruptured intracranial aneurysms has been mainly based on the size of the aneurysm. The contribution of morphological characteristics to treatment decisions of unruptured aneurysms has not been well studied in a systematic and location specific manner. We present a large sample of basilar artery tip aneurysms (BTA) that were assessed using a diverse array of morphological variables to determine the parameters associated with ruptured aneurysms. Demographic and clinical risk factors of aneurysm rupture were obtained from chart review. CT angiograms (CTA) were evaluated with Slicer, an open source visualization and image analysis software, to generate 3-D models of the aneurysms and surrounding vascular architecture. Morphological parameters examined in each model included aneurysm volume, aspect ratio, size ratio, aneurysm angle, basilar vessel angle, basilar flow angle, and vessel to vessel angles. Univariate and multivariate analyses were performed to determine statistical significance. From 2008-2013, 54 patients with BTA aneurysms were evaluated in a single institution, and CTAs from 33 patients (15 ruptured, 18 unruptured) were available and analyzed. Aneurysms that underwent reoperation, that were associated with arteriovenous malformations, or that lacked preoperative CTA were excluded. Multivariate logistic regression revealed that a larger angle between the posterior cerebral arteries (P1-P1 angle, p = 0.037) was most strongly associated with aneurysm rupture after adjusting for other morphological variables. In this location specific study of BTA aneurysms, the larger the angle formed between posterior cerebral arteries was found to be a new morphological parameter significantly associated with ruptured BTA aneurysms. This is a physically intuitive parameter that can be measured easily and readily applied in the clinical setting.
    PLoS ONE 10/2014; 9(10):e110946. DOI:10.1371/journal.pone.0110946 · 3.53 Impact Factor