Risk Factors of Middle Cerebral Artery Aneurysm.
Condition: Middle Cerebral Artery Aneurysm
MeSH terms: Intracranial Aneurysm; Aneurysm
Study type: Observational [Patient Registry]

Summary: 
      According to the current view, cerebral aneurysms are acquired degenerative lesions resulting
      from hemodynamic stress. This single-center case-control study will be carried out at the
      Department of Neurosurgery, Regional Hospital in Sosnowiec, Medical University of Silesia in
      Katowice, Poland between June 2015 and June 2017. The aim of the study is to determine
      morphometric and hemodynamic parameters of aneurysmal and non-aneurysmal middle cerebral
      artery (MCA) bifurcations and to analyze their relationship with aneurysm formation. A
      minimum of 75 cases and 75 age- and sex-matched controls will be required for the study.
      Characteristics of the MCA bifurcations will be determined with computed tomography
      angiography (CTA) and transcranial color-coded sonography (TCCS). The following variables
      will be evaluated as potential risk factors for MCA aneurysm formation: radii and
      cross-sectional area of the main MCA trunk and its branches, tortuosity of MCA trunk,
      asymmetry ratio, area ratio, the angle between the post-bifurcation branches, the angles
      between the MCA trunk and the larger and smaller branch, volume flow rate, mean flow velocity
      and pulsatility index of the MCA. All morphometric and hemodynamic parameters will be
      assessed as potential risk factors for MCA aneurysm formation.
    

Detailed description: 
      Current evidence suggests that a principal factor involved in formation, enlargement and
      rupture of cerebral aneurysms are hemodynamic forces acting at arterial bifurcation. The
      objective of this case-control study is to determine morphometric and hemodynamic parameters
      of aneurysmal and non-aneurysmal MCA bifurcations and to analyze their relationship with
      aneurysm formation. This single-center case-control study will be carried out at the
      Department of Neurosurgery, Regional Hospital in Sosnowiec, Medical University of Silesia in
      Katowice, Poland between June 2015 and June 2017. The study will include patients (cases)
      with unruptured MCA aneurysm diagnosed on three-dimensional computed tomography angiography
      (3D CTA). The controls will be patients with no evidence of intracranial pathologies on 3D
      CTA, referred to establish the etiology of minor symptoms, such as headache or vertigo. A
      minimum of 75 cases and 75 age- and sex-matched controls will be required for the study.

      CTA scans data in DICOM format will be transferred to Mimics Innovation Suite (MIS) platform
      (Materialise, Leuven, Belgium). Image segmentation and creation of three-dimensional (3D)
      models will be carried out with Mimics v.17.0 MIS software (Materialise, Leuven, Belgium).
      The segmentation process will include main trunks of the MCA and the post-bifurcation
      branches. Trifurcations of the main MCA trunk will be excluded from the morphometric
      analysis. MCA bifurcations from the aneurysm patients will be divided into two groups: the An
      group with aneurysmal MCA bifurcations and the non-An group with contralateral non-aneurysmal
      MCA bifurcations. Also, MCA bifurcations from the controls will be divided into two groups:
      R-MCA group with bifurcations of the right MCA and the L-MCA group with bifurcations of the
      left MCA. Morphometric analysis will include the following parameters: radii and
      cross-sectional area of the main MCA trunk and its branches (for the larger and smaller
      branch, respectively), tortuosity of MCA trunk, asymmetry ratio, area ratio, the angle
      between the post-bifurcation branches, the angles between the MCA trunk and the larger and
      smaller branch. All TCCS examinations will be performed using a Vivid 3 Pro (GE Healthcare,
      Chicago, Illinois, USA) equipped with a multi-frequency transcranial probe (1.5-3.6 MHz).
      Angle-corrected mean blood flow velocity, peak systolic velocity and end-diastolic velocity
      will be measured for both MCAs. Pulsatility index and volume flow rate in each vessel will be
      calculated as well. The protocol of the study was approved by the Institutional Review Board,
      and written informed consent will be sought from all the study participants. All morphometric
      and hemodynamic parameters will be assessed as potential risk factors for MCA aneurysm
      formation.
    

Intervention name(s): Computed tomography angiography (3D CTA); Transcranial color-coded sonography (TCCS)
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): CTA scans data in DICOM format was used to morphometric analysis of aneurysmal and non-aneurysmal MCA bifurcations.; TCCS was used to assess of hemodynamic parameters of aneurysmal and non-aneurysmal MCA bifurcations.
Observational model: Case-Control
Time perspective: Other
Sampling method: Non-Probability Sample
Study population: 
        The study will include patients (further referred to as cases) with unruptured MCA aneurysm
        diagnosed on three-dimensional computed tomography angiography (3D CTA).

        The controls will be patients with no evidence of intracranial pathologies on 3D CTA,
        referred to establish the etiology of minor symptoms, such as headache or vertigo.
      
Keywords: Middle Cerebral Artery; Cerebral Aneurysm; Transcranial Color-Coded Sonography; Three-Dimensional Computed Tomography Angiography