Biomaterials and the Central Nervous System: Neurosurgical Applications of Materials Science - Biomaterials Science: An Integrated Clinical and Engineering Approach - page 137

subarachnoid space to another potential space in the body where the fluid
will be readily absorbed. This method of diverting CSF has been used for
over fifty years [1, 13, 14]. The typical shunt system comprises a proximal
catheter (which sits in the ventricular or subarachnoid space) that connects
to a valve that controls drainage of CSF and a distal catheter that carries the
CSF to a distal location (Figure 6.1). The most common targets for CSF reab-
sorption are the peritoneal cavity, the right atrium of the heart, the pleural
space, and more rarely the gall bladder [15, 16]. CSF shunt systems are made
from medical-grade silicone, which would appear to be an ideal material
given its low toxicity, stability, and minimal biological reactivity [1]. While
shunt systems are highly effective in treating hydrocephalus, the hardware
failure rates from shunt malfunctions or infections are extremely high.
Eighty percent of newly placed shunts will succumb to obstruction within
Ventricular Catheter
Distal Catheter
Valve
FIGuRE 6.1
Ventriculoperitoneal shunt system. (Photograph courtesy of Codman © 2007 Codman &
Shurtleff, Inc.)