Problems of long-term cannulation of cisterna magna and subarachnoid space in the conscious dog.--Technical note--

Studies on the influence of substances on the central nervous system and on the function of the blood-CSF-barrier made long-term cannulation of the CSF compartment interesting. This study was to test, whether a permanent CSF-drainage from any point of the subarachnoid space was possible with modified "tissue cages" (Guyton 1963). For that purpose a steel wire cage and a teflon cage were implanted subarachnoidally into beagle dogs. The two cages stopped draining on the second and on the third day respectively. Histological examination showed, that, because of the strong reaction of animal tissue to implanted material, direct cannulation of the CSF compartment does not seem feasible. In the second part the "Manuilov-system" was modified. An indwelling guiding tube was implanted and fixed with a horseshoe shaped plate to the occipital bone. Puncture can be made on the awake dog without local anaesthetic and produces samples of 1.5 to 2.0 ml CSF for up to 30 days without complications.