Indications for cerebrospinal fluid drainage and avoidance of complications.

An understanding of normal CSF physiology is a prerequisite to treating problems such as CSF fistulae and pseudomeningoceles. CSF diversion techniques fall into two categories, external and internal. External lumbar drainage is useful when temporary CSF diversion is necessary (eg, in cases necessitating manipulation and retraction of the brain to gain access to deep lesions) and in treating otorrhea or rhinorrhea following traumatic or iatrogenic insults to the cranial base. Drawbacks include insertion discomfort and limited duration of therapy.LP and VP shunts came into widespread use in the 1970s, and both systems share risks of bowel perforation, obstruction, over drainage and wound-related complications. In addition, VP shunts add the risks of intracerebral hematoma and ventriculitis. New valve technology has made it possible to alter the volume drained, thus alleviating problems of over-and under drainage.