Have we made progress in preventing shunt failure? A critical analysis

Object. The goal of this study was to determine whether failure rates of hydrocephalus shunts have fallen over the years as a result of experience or technical improvements. Methods. A structured search was performed of the English language literature for case series reporting failure rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to analyze failure rates statistically for temporal trends. Separate models were used for children (< 17 years old) and adults. Results. In children, the shunt failure rate was 31.3% for the 1st year and 4.5% per year thereafter. There were no significant changes in either rate over time. Although 1st-year failure rates in adults have fallen slightly over time, late failure rates have risen. Conclusions. Progress in preventing shunt failures has not been made over the last several decades. Any improvements made in shunt materials or insertion techniques have been overshadowed by biological and other factors.