Objective: The primary objective of this study was to use the prospective Hydrocephalus Clinical Research Network (HCRN) registry to determine clinical predictors of fast time to shunt failure (≤ 30 days from last revision) and ultrafast time to failure (≤ 7 days from last revision).
Methods: Revisions (including those due to infection) to permanent shunt placements that occurred between April 2008 and November 2017 for patients whose entire shunt experience was recorded in the registry were analyzed. All registry data provided at the time of initial shunt placement and subsequent revision were reviewed. Key variables analyzed included etiology of hydrocephalus, age at time of initial shunt placement, presence of slit ventricles on imaging at revision, whether the ventricles were enlarged at the time of revision, and presence of prior fast failure events. Univariable and multivariable analyses were performed to find key predictors of fast and ultrafast failure events.
Results: A cohort of 1030 patients with initial shunt insertions experienced a total of 1995 revisions. Of the 1978 revision events with complete records, 1216 (61.5%) shunts remained functional for more than 1 year, and 762 (38.5%) failed within 1 year of the procedure date. Of those that failed within 1 year, 423 (55.5%) failed slowly (31-365 days) and 339 (44.5%) failed fast (≤ 30 days). Of the fast failures, 131 (38.6%) were ultrafast (≤ 7 days). In the multivariable analysis specified a priori, etiology of hydrocephalus (p = 0.005) and previous failure history (p = 0.011) were independently associated with fast failure. Age at time of procedure (p = 0.042) and etiology of hydrocephalus (p = 0.004) were independently associated with ultrafast failure. These relationships in both a priori models were supported by the data-driven multivariable models as well.
Conclusions: Neither the presence of slit ventricle syndrome nor ventricular enlargement at the time of shunt failure appears to be a significant predictor of repeated, rapid shunt revisions. Age at the time of procedure, etiology of hydrocephalus, and the history of previous failure events seem to be important predictors of fast and ultrafast shunt failure. Further work is required to understand the mechanisms of these risk factors as well as mitigation strategies.
Keywords: hydrocephalus; shunt failure; shunt revision; ventriculoperitoneal shunt.