Interstitial pressure, volume, and flow during infusion into brain tissue.
A model of infusion-induced swelling in the brain is presented, in which gray and white matter are treated as poroelastic media. The distributions of interstitial pressure, flow, and volume are derived for steady-state and transient infusion protocols. A significant percentage increase in interstitial volume is predicted near the injection site, despite only a modest increase in tissue-averaged fluid content there. The model also can be used to estimate mechanical parameters of brain tissue, such as its hydraulic permeability, shear modulus, and Lamé constant. A solute transport equation that incorporates tissue swelling is also presented. This work suggests that knowing the distribution of swelling induced by infusion is a prerequisite to describing interstitial transport of solutes.
Basser
P J
PJ
Mechanical Engineering Section, National Institutes of Health, Bethesda, Maryland 20892.
D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000378:metabolism*; D001927:Brain Diseases / Q000503:physiopathology*; D005110:Extracellular Space / Q000502:physiology; D006801:Humans; D007263:Infusions, Parenteral; D008962:Models, Theoretical