209. Pediatric Neurosurgeon’s Bane: Clustered Shunt Failure. An Analysis of Risk Factors

Authors: Brandon G. Rocque, MD, MS, FAANS; Raymond Waldrop, BS; Anastasia Arynchyna, MPH; Rena Lim; Katherine Barnes; Tammie Kerr; James Johnston, MD; Jeffrey Blount, MD; Curtis Rozzelle, MD (Birmingham, AL)

Introduction:

Repeated failure of ventriculoperitoneal shunts (VPS) is a problem feared by pediatric neurosurgeons and patients. While many studies have identified factors associated with first shunt failure, studies of subsequent failures are much less common. The purpose of this study is to identify patients who have experienced a cluster of shunt failures (defined as 3 or more VPS operations within 2 months) and determine risk factors for clustered shunt failure.

Methods:

We reviewed prospectively collected records from all patients who underwent VPS surgery from 2008 to 2019 at our institution, including only those children who had received all of their hydrocephalus care at our institution with at least 3 years’ follow up. We analyzed demographics, etiology of hydrocephalus, history of ETV or temporizing procedure, initial valve type, age at shunt placement, ventricle size (both at initial shunt placement and 1-year later), and head circumference z-score (HC). Fisher exact test and logistic regression were used to test association of each variable with history of clustered shunt failure.

Results:

Of 416 included children, 23 (5.5%) had experienced at least one cluster of shunt failures. Only gestational age at birth (OR=0.92, 95% CI 0.86 – 0.99, p= 0.020) and HC at initial shunt placement (OR = 0.90, 95% CI 0.82 – 0.99, p=0.029) showed significant association with clustered shunt failure. OR less than one indicates that increasing gestational age and increasing HC are associated with lower odds of clustered shunt failure. 

Conclusion:

Clustered shunt failure was observed in 5% of our sample and was associated with lower gestational age and lower HC at time of initial shunt placement.  Further study is needed to verify these findings; it may be that allowing a larger head circumference prior to shunt placement could protect against future clusters of VPS failure.