Angiosynizesis – Venous Behaviour, Out Flow from Brain via Skull Base

The author described from biomechanical aspect with correlation of anatomical study s flow into the bridging brain veins as unique out-flow modelling system and decribed problem of angiosynizesis.

The fluid structure interaction is studied experimentally on the special experimental line. The fluid structure phenomenon is investigated both the continuous and pulsatile flow is evaluated by non-invasive optical method and verified by the invasive pressure method.

The above problems are numerically modeled by the finite element method. The weak formulation is based on the virtual work principle. The mixed formulation of the finite element method with the separately interpolated pressure is used for the structure. To described wider class of problems we consider in the simulation the three material models: the Neo-Hookean, the isotropic Gent model and the anisotropic Gent material model to include the influence of collagen structure of blood vessels. The fluid is modeled as Newtonian liquid. The strong coupling of both structure and fluid solvers allow us to simulate large deflection ocillations of the structure.

The simultaneous clinics observation (histological findings), in vitro experiments and numerical modeling gives sufficient data to predict biomechanical conditions of the angiosynizesis.

The main goal of developed theory is to formulate the biomechanical conditions (geometrical dimensions, viskoelastic properties of veins and blood fluid flow conditions) at which an unstable behavior or even the vein collapse can occur.

From the biomechanical aspects can be the experimental findings summarized as follows:

• the existence of two type of venous brain systems; thin wall and thick wall veins with the one order different elastic modulus magnitude

• the high sensitivity of the thin wall veins on the blood flow rate and extension or contraction on their structural stability

• the existence of continuing small wall vibration under physiological conditions

The diagnosis - pseudotumor cerebri – has very more hypothesis about pathophysiological pathways of its. Under study of literature review about this diagnosis we revised pathophysiological pathways going to the pseudotumor cerebri as non-thrombotic theory.

The author studies the physiological phemonens of bridging veins and brain outflow.

The fluid structure interaction is studied experimentally on the special experimental line. The biomechanical, histological study and biomechanical and mathematical modeling the function of bridging veins and venous sinuses we developed a new pathways of this diagnosis.

Under this study author developing any questions and answers on basic problems in animals – why developing hemodymically pulse blood flow in cardiovascular system. He discussed the problems of exchanges pulsing and non-pulsing system and what developing after this exchanges (problem of intraarterial stents, treatment of stoke, embolisation of aneurysms i.e.).

The collaborative problems with the hemodynamic flow of brain are so-call “the movements of brain” – the biomechanical effects of the wave-interaction of the brain (the breathing, arterial pulse, venous pulse, cerebrospinal fluid pulse and flow) into skull.