ANALYSIS OF FACTORS AFFECTING MULTIPLE SHUNT FAILURES

Ventricular shunts that require multiple revisions are familiar to neurosurgeons. We conducted a retrospective study to determine whether patients who require repeated shunt revisions represent a particular phenomenon within shunted hydrocephalic children. The clinical records of 244 children who had undergone shunt procedures between January 1996 and January 2002 were examined. They were divided into: Group 1: children with no shunt failure (n = 136), group 2: children with one shunt revision (n= 52), Group 3: children with 2 or 3 shunt revisions (n =34), and Group 4: patients who had 4 or more revisions (n= 22). Patients in group 3 and 4 accounted for 54.8% of total of 531 shunt procedures. Etiology of hydrocephalus, nature of the dysfunction, and variables related to the surgical procedure were analyzed for each group. We observed a progressive shortening of the intervals between revisions as the numbers of surgeries increased, indicating that shunts that tend to fail repeatedly did so sooner than those that did not. The study showed that group 2 had slower rate of failure than either group3 or group4. The etiologies of the hydrocephalus were not randomly distributed among the four groups; there was a predominance of congenital conditions in groupl. Repeated shunt revisions were associated with a progressive increase in the concentration of monocytes in the CSF. Our data suggest that multiple shunt revisions constitute a phenomenon that may be caused by specific, still unidentified, biological factors.