Suggestions for the construction of a flow-reducing device in the treatment of hydrocephalic children, based on clinical and experimental results.

A few hydrocephalic children originally shunted for progressive hydrocephalus become shunt-independent later on (5). The most important mechanisms resulting in shunt independence are, on the one hand, induced by growth, and, on the other hand, the gradually diminishing function and, finally, occlusion of the vascular catheter. With a flow-reducing device it should be possible to imitate this mechanism, resulting in appropriate cases in shunt independence within a predictable time. Instead of by growth, the reduction of flow and finally, the occlusion, could be achieved in such a device by the normal CSF contents. In preliminary examinations we studied retrospectively the behaviour of soft tissue in 9 proximal and distal obstructions of different derivation systems, as well as the influence of the shunt parts on the CSF content of cells and proteins. Soft tissues always lead to an obstruction by the ependyma or by a fibrinous plug; however, an intraluminar invasion of cells was never found. Incubation of different parts of the shunt system with mononuclear leucocytes did not lead to a decreased survival of cells, and the amount of cells in shunted children compared to unaffected ones did not show any difference. CSF proteins in 54 hydrocephalic children are on the average similar to a normal population of the same age distribution (3, 4). Experimental work on 22 different membrane types is presented in respect of their technical aspects and laboratory findings. Membranes with a pore diameter from 0.05 to 10 micron were perfused in a sterile unit at constant temperature with artificial CSF of 20 times augmented concentration in proteins (8).(ABSTRACT TRUNCATED AT 250 WORDS)