Turbulence in human intracranial saccular aneurysms

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✓ Preliminary experiments with glass model bifurcation aneurysms demonstrated that turbulent flow pattern occurs in the sac of an aneurysm at a low flow rate (critical Reynolds number, 400 ± 10 S.E.M.). A prediction that flow is turbulent in the sac of human intracranial saccular aneurysms was confirmed in a clinical study. Bruits, indicative of turbulence, were recorded with a phonocatheter from the sacs of 10 out of 17 intracranial aneurysms exposed at surgery where the mean arterial pressures were above 50 mm Hg. The amplitude of the bruits varied with the pressure. All of the patients in whom no bruit was found had profound Arfonad hypotension at the time of recording.

Turbulence causes vibration in the wall of a vessel. This vibration produces and accelerates degenerative changes in vascular tissue by a process similar to the structural fatigue of metals by vibration. The author proposes that the turbulent blood flow within an aneurysm contributes to the degeneration of the elastica, and the production of the atheromatous changes, characteristically seen in its wall. This weakens the wall causing continuing enlargement and eventual rupture.

Article Information

Address reprint requests to: Gary G. Ferguson, M.D., Department of Biophysics, Faculty of Medicine, The University of Western Ontario, London 72, Ontario, Canada.

© AANS, except where prohibited by US copyright law.

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Figures

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    Left: Turbulence in the sac of the large spherical glass model aneurysm. The Reynolds number (Re 500) corresponds to the flow rate at which the photograph was taken. The direction of flow is shown by the arrow. Evans blue dye has been injected to demonstrate the flow patterns. Right: Turbulence in both loculi of the large bilocular glass model aneurysm. Flow in the stem and both branches is streamlined.

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    Intracardiac phonocatheter used for recording bruits from intracranial saccular aneurysms exposed at surgery.

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    Block diagram of instrumentation used for the recording and analysis of bruits.

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    Case 2. Left middle cerebral bifurcation aneurysm, anteroposterior view. The line drawing on the right shows the three phonocatheter recording sites used in this case: the fundus of the aneurysm, a small middle cerebral bifurcation, and a branch of that bifurcation.

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    Case 2. Light-beam oscillograph record of bruits at mean systemic arterial pressure of 90 mm Hg. The amplitude scales on the left are related to a standard calibrating signal of 500 µV. The upper records are at a chart speed of 1 cm/sec. The amplitude is maximal from the aneurysm. The lower record is at a chart speed of 10 cm/sec, which illustrates the characteristic diamond-shaped profile of the bruits with systolic accentuation.

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    Case 4. Right middle cerebral bifurcation aneurysm, lateral view. Phonocatheter recordings were made from the sac and neck of the aneurysm and a main branch of the bifurcation.

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    Case 4. Light-beam oscillograph record of bruits from the sac of the aneurysm at a mean systemic arterial pressure of 80 mm Hg. The upper record is at a chart speed of 5 cm/sec, the lower at 40 cm/sec. In this case the bruit is continuous through systole and diastole, with sudden accentuation in systole. The predominant frequency of the murmur (560 ± 30 Hz) can be calculated from the fast record by counting the number of spikes (cycles) over a given time period. The regular periodicity and almost pure musical quality of the bruit is evident.

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    Case 10. Right anterior communicating artery aneurysm, oblique view. Phonocatheter recordings were made from the sac, the right anterior cerebral artery, and the right pericallosal artery.

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    Case 10. Light-beam oscillograph record of bruits at a mean systemic arterial pressure of 50 mm Hg. The upper records are at a chart speed of 1 cm/sec, the lower at 5 cm/sec.

References

  • 1.

    CoulterN. A.Jr. and PappenheimerJ. R. Development of turbulence in flowing blood. Am. J. Physiol.1949159:401408.Coulter N. A. Jr. and Pappenheimer J. R. Development of turbulence in flowing blood. Am. J. Physiol. 1949 159:401–408.

    • Search Google Scholar
    • Export Citation
  • 2.

    CrawfordT. Some observations on the pathogenesis and natural history of intracranial aneurysms. J. Neurol. Neurosurg. Psychiat.195922:259266.Crawford T. Some observations on the pathogenesis and natural history of intracranial aneurysms. J. Neurol. Neurosurg. Psychiat. 1959 22:259–266.

    • Search Google Scholar
    • Export Citation
  • 3.

    CromptonM. R. Mechanism of growth and rupture in cerebral berry aneurysms. Br. med. J.19661:11381142.Crompton M. R. Mechanism of growth and rupture in cerebral berry aneurysms. Br. med. J. 1966 1:1138–1142.

    • Search Google Scholar
    • Export Citation
  • 4.

    DrakeC. G. The surgical treatment of vertebral-basilar aneurysms. Clin. Neurosurg.196916:114169.Drake C. G. The surgical treatment of vertebral-basilar aneurysms. Clin. Neurosurg. 1969 16:114–169.

    • Search Google Scholar
    • Export Citation
  • 5.

    FergusonG. G.ScottS. and RoachM. R. Flow at bifurcations. (To be published.)Ferguson G. G. Scott S. and Roach M. R. Flow at bifurcations. (To be published.)

  • 6.

    FinnertyF. A.Jr.WitkinL. and FazekasJ. F. Cerebral hemodynamics during cerebral ischemia induced by acute hypotension. J. clin. Invest.195433:12271232.Finnerty F. A. Jr.Witkin L. and Fazekas J. F. Cerebral hemodynamics during cerebral ischemia induced by acute hypotension. J. clin. Invest. 1954 33:1227–1232.

    • Search Google Scholar
    • Export Citation
  • 7.

    ForbusW. D. On the origin of miliary aneurysms of superficial cerebral arteries. Bull. Johns Hopkins Hosp.193047:239284.Forbus W. D. On the origin of miliary aneurysms of superficial cerebral arteries. Bull. Johns Hopkins Hosp. 1930 47:239–284.

    • Search Google Scholar
    • Export Citation
  • 8.

    FryD. L. Acute vascular endothelial changes associated with increased blood velocity gradients. Circulation Res.196822:165197.Fry D. L. Acute vascular endothelial changes associated with increased blood velocity gradients. Circulation Res. 1968 22:165–197.

    • Search Google Scholar
    • Export Citation
  • 9.

    FryD. L. Certain histological and chemical responses of the vascular interface to acutely induced mechanical stress in the aorta of the dog. Circulation Res.196924:93108.Fry D. L. Certain histological and chemical responses of the vascular interface to acutely induced mechanical stress in the aorta of the dog. Circulation Res. 1969 24:93–108.

    • Search Google Scholar
    • Export Citation
  • 10.

    GermanW. J. and BlackS. P. W. Experimental production of carotid aneurysms. New Engl. J. Med.1954250:104106.German W. J. and Black S. P. W. Experimental production of carotid aneurysms. New Engl. J. Med. 1954 250:104–106.

    • Search Google Scholar
    • Export Citation
  • 11.

    GermanW. J. and BlackS. P. W. Intra-aneurysmal hemodynamics: turbulence. Trans. Am. neurol. Ass.195479:163165.German W. J. and Black S. P. W. Intra-aneurysmal hemodynamics: turbulence. Trans. Am. neurol. Ass. 1954 79:163–165.

    • Search Google Scholar
    • Export Citation
  • 12.

    HardestyW. H.RobertsB.TooleJ. F. and RoysterH. P. Studies of carotid-artery blood flow in man. New Engl. J. Med.1960263:944946.Hardesty W. H. Roberts B. Toole J. F. and Royster H. P. Studies of carotid-artery blood flow in man. New Engl. J. Med. 1960 263:944–946.

    • Search Google Scholar
    • Export Citation
  • 13.

    HasslerO. Morphological studies on the large cerebral arteries with reference to the aetiology of subarachnoid haemorrhage. Acta psychiat. neurol. scand.1961suppl. 154145 pp.Hassler O. Morphological studies on the large cerebral arteries with reference to the aetiology of subarachnoid haemorrhage. Acta psychiat. neurol. scand. 1961 suppl. 154 145 pp.

    • Search Google Scholar
    • Export Citation
  • 14.

    KikutR. P. Experimental studies of intra-aneurysmal blood flow. Vop. Neurokhir.19662:1721.Kikut R. P. Experimental studies of intra-aneurysmal blood flow. Vop. Neurokhir. 1966 2:17–21.

    • Search Google Scholar
    • Export Citation
  • 15.

    LassenN. A. Cerebral blood flow and oxygen consumption in man. Physiol. Rev.195939:183238.Lassen N. A. Cerebral blood flow and oxygen consumption in man. Physiol. Rev. 1959 39:183–238.

    • Search Google Scholar
    • Export Citation
  • 16.

    NyströmS. H. M. Cytological aspects of the pathogenesis of intracranial aneurysms. In: Intracranial aneurysms and subarachnoid haemorrhage. FieldsW. S. and SahsA. L. Eds. Springfield, Ill.: Charles C Thomas1965518 pp. (See pp. 4069.)Nyström S. H. M. Cytological aspects of the pathogenesis of intracranial aneurysms. In: Intracranial aneurysms and subarachnoid haemorrhage. Fields W. S. and Sahs A. L. Eds. Springfield Ill.: Charles C Thomas 1965 518 pp. (See pp. 40–69.)

    • Search Google Scholar
    • Export Citation
  • 17.

    NyströmS. H. M. Development of intracranial aneurysms as revealed by electron microscopy. J. Neurosurg.196320:329337.Nyström S. H. M. Development of intracranial aneurysms as revealed by electron microscopy. J. Neurosurg. 1963 20:329–337.

    • Search Google Scholar
    • Export Citation
  • 18.

    ReynoldsO. An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous and of the law of resistance in parallel channels. Phil. Trans. R. Soc.1883174:935987.Reynolds O. An experimental investigation of the circumstances which determine whether the motion of water shall be direct or sinuous and of the law of resistance in parallel channels. Phil. Trans. R. Soc. 1883 174:935–987.

    • Search Google Scholar
    • Export Citation
  • 19.

    RichardsonC. and KofmanO. Cranial bruit with intracranial saccular aneurysms. Trans. Am. neurol. Ass.195176:151154.Richardson C. and Kofman O. Cranial bruit with intracranial saccular aneurysms. Trans. Am. neurol. Ass. 1951 76:151–154.

    • Search Google Scholar
    • Export Citation
  • 20.

    RoachM. R. Changes in arterial distensibility as a cause of poststenotic dilation. Am. J. Cardiol.196312:802815.Roach M. R. Changes in arterial distensibility as a cause of poststenotic dilation. Am. J. Cardiol. 1963 12:802–815.

    • Search Google Scholar
    • Export Citation
  • 21.

    SahsA. L. Observations on the pathology of saccular aneurysms. J. Neurosurg.196624:792806.Sahs A. L. Observations on the pathology of saccular aneurysms. J. Neurosurg. 1966 24:792–806.

    • Search Google Scholar
    • Export Citation
  • 22.

    StehbensW. E. Histopathology of cerebral aneurysms. Archs Neurol. Chicago19638:277285.Stehbens W. E. Histopathology of cerebral aneurysms. Archs Neurol. Chicago 1963 8:277–285.

    • Search Google Scholar
    • Export Citation
  • 23.

    StehbensW. E. Turbulence of blood flow. Q. J. exp. Physiol.195944:110117.Stehbens W. E. Turbulence of blood flow. Q. J. exp. Physiol. 1959 44:110–117.

    • Search Google Scholar
    • Export Citation
  • 24.

    TindallG. T.OdomG. L.CuppH. B.Jr. and DillonM. L. Studies on carotid artery flow and pressure. Observations in 18 patients during graded occlusion of proximal carotid artery. J. Neurosurg.196219:917923.Tindall G. T. Odom G. L. Cupp H. B. Jr. and Dillon M. L. Studies on carotid artery flow and pressure. Observations in 18 patients during graded occlusion of proximal carotid artery. J. Neurosurg. 1962 19:917–923.

    • Search Google Scholar
    • Export Citation
  • 25.

    TominagaS. An experimental study of hemodynamic factors in the rupture of intracerebral aneurysms. Arch. jap. Chir.196635:6788.Tominaga S. An experimental study of hemodynamic factors in the rupture of intracerebral aneurysms. Arch. jap. Chir. 1966 35:67–88.

    • Search Google Scholar
    • Export Citation
  • 26.

    WalkerA. E. and AllegreW. The pathology and pathogenesis of cerebral aneurysms. J. Neuropath. exp. Neurol.195413:248259.Walker A. E. and Allegre W. The pathology and pathogenesis of cerebral aneurysms. J. Neuropath. exp. Neurol. 1954 13:248–259.

    • Search Google Scholar
    • Export Citation
  • 27.

    WallaceJ. D.BrownJ. R.Jr.LewisD. H. DeitzG. W. and ErtugrulA. Intracardiac acoustics. J. acoust. Soc. Am.195931:712723.Wallace J. D. Brown J. R. Jr.Lewis D. H. Deitz G. W. and Ertugrul A. Intracardiac acoustics. J. acoust. Soc. Am. 1959 31:712–723.

    • Search Google Scholar
    • Export Citation
  • 28.

    WaltonJ. N. Subarachnoid haemorrhage. Edinburgh and London: E. & S. Livingstone Ltd.1956350 pp. (See pp. 114115.)Walton J. N. Subarachnoid haemorrhage. Edinburgh and London: E. & S. Livingstone Ltd. 1956 350 pp. (See pp. 114–115.)

    • Search Google Scholar
    • Export Citation

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