A study was performed to evaluate the efficacy of closed continuous drainage (CCD) via a lumbar subarachnoid catheter for prevention or treatment of CSF fistulas. In addition to the analysis of the physical, chemical and biological properties of the CSF obtained, the catheters themselves were tested on removal to identify any microorganisms contaminating them. Other factors taken into consideration were the symptoms reported by the patients during positioning of the catheter and while it was in place, any variations in body temperature and local inflammatory effects on the nerve roots of the cauda equine and surrounding tissues. The low percentage of systemic and local infections observed testifies to the safety of this method, regardless of the duration of treatment.