Oxygen transfer in a convection-enhanced hollow fiber bioartificial liver

A mathematical model was developed to predict oxygen transport in a hollow fiber bioartificial liver device. The model parameters were taken from the HepatAssist 2000 device, a plasma perfused hollow fiber cartridge with prim ary hepatocytes seeded in the extracapillary space. Cellular oxygen uptake was based on Michaelis-Menten kinetics. Oxygen transport due to the convect ive flow of plasma into the extracapillary space was considered. The effect of modulating several important parameters was investigated, namely, the M ichaelis-Menten constant V-m (the maximum oxygen consumption per unit volum e of the cell mass), the oxygen partial pressure, the now rate of the plasm a at device inlet, and the permeability of the cell mass contained in the e xtracapillary space. A computer implementation of the model was used to ass ess whether a given number of cells could be maintained within such a devic e. The results suggest that a substantial proportion of the hepatocytes are exposed to hypoxic conditions under which metabolism may be impaired.