Lumbo-omental shunt for drainage of cerebrospinal fluid--an experimental radionuclide study in dogs. II. Evaluation of transport routes from lumbar subarachnoid space to venous blood.

In a series of dogs, the transport routes of intrathecally administered 99Tcm-DTPA from an omental graft to the venous blood were studied by scintillation probes placed over the portal and external jugular veins and by blood samples from the inferior vena cava. It was found early in the course of investigation that a rich revascularization frequently occurred between the transplanted omentum and the surrounding muscles. In all dogs, the omental graft was divided, in its muscle tunnel about 5 cm outside the dural sac, 13--19 months after the implantation. Even after this a rapid transport to the venous system of radionuclide could be demonstrated. The revascularization of the graft was also studied morphologically in two dogs means of microangiography.