Dr Georgios Varsos

Georgios Varsos

University position

PhD student
Supervised by Marek Czosnyka

Departments

Department of Clinical Neurosciences

Institutes

Neurosurgery Unit

Email

georgios.varsos@cantab.net

Home page

http://www.georgios-varsos.com (personal home page)

Research Theme

Clinical and Veterinary Neuroscience

Interests

My focus has been on modelling of brain haemodynamics, particularly describing a terminal situation of cerebral circulation, associated with ischemic strokes. A new methodology was created which can be used for estimating brain’s zero-flow pressure or critical closing pressure (CrCP): a critical threshold for arterial blood pressure (ABP). If ABP falls below CrCP, the local blood pressure inside small vessels of microcirculation is no longer adequate to keep them open, leading them to a collapse, ceasing blood flow.

The new method eliminated the main drawback of previous methods, which were presenting non-physiological negative values; CrCP can now instead be considered as a reliable tool for physicians. A new mechanism was further introduced, which can quantify a patient’s ischemic risk during haemodynamic changes. In neurointensive care, this mechanism might provide a reference point to guidance of treatment in terms of terminal ischemia associated with collapsing vessels.

A new mechanism for assesing brain ischemia during intracranial hypertension
A new mechanism for assesing brain ischemia during intracranial hypertension
Click image to view full-size

Research Focus

Keywords

brain

modelling

haemodynamics

critical closing pressure

Clinical conditions

Hydrocephalus

Spinal cord injury

Subarachnoid hemorrhage

Traumatic brain injury

Traumatic brain injury

Equipment

Computational modelling

Haemodynamic monitoring

Collaborators

Cambridge

Marek Czosnyka

John Pickard

Associated News Items


    Key publications

    Varsos GV, de Riva N, Smielewski P, Pickard JD, Brady KM, Reinhard M, Avolio A, Czosnyka M (2013), “Critical Closing Pressure During Intracranial Pressure Plateau Waves.” Neurocrit Care Details

    Varsos GV, Richards HK, Kasprowicz M, Reinhard M, Smielewski P, Brady KM, Pickard JD, Czosnyka M (2013), “Cessation of Diastolic Cerebral Blood Flow Velocity: The Role of Critical Closing Pressure.” Neurocrit Care Details

    Varsos GV, Richards H, Kasprowicz M, Budohoski KP, Brady KM, Reinhard M, Avolio A, Smielewski P, Pickard JD, Czosnyka M (2012), “Critical closing pressure determined with a model of cerebrovascular impedance.” J Cereb Blood Flow Metab Details

    Publications

    2015

    Phang I, Werndle MC, Saadoun S, Varsos GV, Czosnyka M, Zoumprouli A, Papadopoulos MC (2015), “Expansion Duroplasty Improves Intraspinal Pressure, Spinal Cord Perfusion Pressure and Vascular Pressure Reactivity Index in Patients with Traumatic Spinal Cord Injury.” J Neurotrauma Details

    Varsos GV, Kolias AG, Smielewski P, Brady KM, Varsos VG, Hutchinson PJ, Pickard JD, Czosnyka M (2015), “A noninvasive estimation of cerebral perfusion pressure using critical closing pressure.” J Neurosurg :1-11 Details

    2014

    Budohoski KP, Czosnyka M, Kirkpatrick PJ, Reinhard M, Varsos GV, Kasprowicz M, Ząbek M, Pickard JD, Smielewski P (2014), “Bilateral Failure of Cerebral Autoregulation is Related to Unfavorable Outcome After Subarachnoid Hemorrhage.” Neurocrit Care Details

    Budohoski KP, Kirkpatrick PJ, Smielewski P, Reinhard M, Varsos GV, Kasprowicz M, Zabek M, Pickard JD, Czosnyka M (2014), “Galbraith Award 133 Bilateral Failure of Cerebral Autoregulation is Related to Unfavorable Outcome After Subarachnoid Hemorrhage.” Neurosurgery 61 Suppl 1:203 Details

    Donnelly J, Czosnyka M, Sudhan N, Varsos GV, Nasr N, Jalloh I, Liu X, Dias C, Sekhon MS, Carpenter KL, Menon DK, Hutchinson PJ, Smielewski P (2014), “Increased Blood Glucose is Related to Disturbed Cerebrovascular Pressure Reactivity After Traumatic Brain Injury.” Neurocrit Care Details

    Liu X, Czosnyka M, Donnelly J, Budohoski KP, Varsos GV, Nasr N, Brady KM, Reinhard M, Hutchinson PJ, Smielewski P (2014), “Comparison of frequency and time domain methods of assessment of cerebral autoregulation in traumatic brain injury.” J Cereb Blood Flow Metab Details

    Nasr N, Czosnyka M, Pavy-Le Traon A, Custaud MA, Liu X, Varsos GV, Larrue V (2014), “Baroreflex and Cerebral Autoregulation Are Inversely Correlated.” Circ J Details

    Rhee CJ, Fraser Iii CD, Kibler K, Easley RB, Andropoulos DB, Czosnyka M, Varsos GV, Smielewski P, Rusin CG, Brady KM, Kaiser JR (2014), “The ontogeny of cerebrovascular pressure autoregulation in premature infants.” J Perinatol Details

    Swallow DM, Fellner N, Varsos GV, Czosnyka M, Smielewski P, Pickard JD, Czosnyka Z (2014), “Repeatability of cerebrospinal fluid constant rate infusion study.” Acta Neurol Scand Details

    Varsos GV, Budohoski KP, Czosnyka M, Kolias AG, Nasr N, Donnelly J, Liu X, Kim DJ, Hutchinson PJ, Kirkpatrick PJ, Varsos VG, Smielewski P (2014), “Cerebral vasospasm affects arterial critical closing pressure.” J Cereb Blood Flow Metab Details

    Varsos GV, Budohoski KP, Kolias AG, Liu X, Smielewski P, Varsos VG, Hutchinson PJ, Pickard JD, Czosnyka M (2014), “Relationship of Vascular Wall Tension and Autoregulation Following Traumatic Brain Injury.” Neurocrit Care Details

    2013

    Dias C, Maia I, Cerejo A, Varsos G, Smielewski P, Paiva JA, Czosnyka M (2013), “Pressures, Flow, and Brain Oxygenation During Plateau Waves of Intracranial Pressure.” Neurocrit Care Details

    Varsos GV, Kasprowicz M, Smielewski P, Czosnyka M (2013), “Model-based Indices Describing Cerebrovascular Dynamics.” Neurocrit Care Details

    Werndle MC, Saadoun S, Phang I, Czosnyka M, Varsos GV, Czosnyka ZH, Smielewski P, Jamous A, Bell BA, Zoumprouli A, Papadopoulos MC (2013), “Monitoring of Spinal Cord Perfusion Pressure in Acute Spinal Cord Injury: Initial Findings of the Injured Spinal Cord Pressure Evaluation Study.” Crit Care Med Details

    2012

    Budohoski KP, Czosnyka M, Smielewski P, Varsos GV, Kasprowicz M, Brady KM, Pickard JD, Kirkpatrick PJ (2012), “Cerebral autoregulation after subarachnoid hemorrhage: comparison of three methods.” J Cereb Blood Flow Metab Details