Volume 169, January 2023, Pages 20-30Author links open overlay panelObjective

Reported rates of failures of internal cerebrospinal fluid shunt (ICSFS) vary greatly from less than 5% to more than 50% and no meta-analysis to assess the overall prevalence has been performed. We estimated the failure rate after ICSFS insertion and searched for associated factors.

Methods

Six databases were searched from January 1990 to February 2022. Only original articles reporting the rate of adult shunt failure were included. Random-effects meta-analysis with a generalized linear mixed model method and logit transformation was used to compute the overall failure prevalence. Subgroup analysis and meta-regression were implemented to search for associated factors.

Results

Of 1763 identified articles, 46 were selected, comprising 70,859 ICSFS implantations and 13,603 shunt failures, suggesting an accumulated incidence of 19.2%. However, the calculated pooled prevalence value and its 95% confidence interval (CI) were 22.7% (95% CI, 19.8–5.8). The CI of the different estimates did not overlap, indicating a strong heterogeneity confirmed by a high I2 of 97.5% (95% CI, 97.1–97.8; P < 0.001; τ2 = 0.3). Ninety-five percent prediction interval of shunt failure prevalence ranged from 8.75% to 47.36%. A meta-regression of prevalence of publication found a barely significant decreasing failure rate of about 2% per year (–2.11; 95% CI, –4.02 to –0.2; P = 0.031).

Conclusions

Despite being a simple neurosurgical procedure, ICSFS insertion has one of the highest risk of complications, with failure prevalence involving more than 1 patient of 5. Nonetheless, all efforts to lower this high level of shunt failure seem to be effective.

Introduction

Hydrocephalus is a common neurologic condition of excessive cerebrospinal fluid (CSF) accumulation within the central nervous system leading to ventricular dilatation and increased intracranial pressure. It can occur at any age but it is most common in infants or in adults older than 60 years, with a mean prevalence of 85/100,000 (95% confidence interval [CI], 62–116) and has a lower incidence in high-income countries.1 Hydrocephalus is caused by numerous congenital and/or acquired diseases through different mechanisms not yet all well understood. Although untreated hydrocephalus may result in progressive neurologic injury and death, resolution of symptoms can be achieved with early diagnosis and neurosurgical intervention. Blocked or obstructive hydrocephalus is preferentially treated by endoscopic third ventriculostomy but, in cases of nonobstructive communicating hydrocephalus, internal CSF shunting (ICSFS) remains the procedure of choice, usually by insertion of a ventriculoperitoneal shunt (VPS). However, ICSFS has a high risk of device-related complications. Despite seeming improvements in surgical techniques and material, shunt failure is still common. Complications usually require urgent surgical revision, have greater associated costs, and can lead to additional complications. Reported rates of shunt failure vary greatly from <5% to >50% but generally range from 20% to 30%.2,3 No meta-analysis to assess the prevalence of ICSFS failure has been reported and there is insufficient information on factors that may influence this frequent complication.

The aim of this systematic review and meta-analysis was to determine the overall rate of ICSFS failure in the adult population and search for associated factors.

Section snippetsMethods

The protocol for this systematic review is registered at PROSPERO (CRD42022339954). This systematic review in reported in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses; http://www.prisma-statement.org/Default.aspx) guidelines.4

Literature Search

The article selection process is shown in Figure 1. A total of 1763 articles were identified in the initial literature search. During title and abstract screening, 497 duplicates were found and 1147 articles were excluded. Of the 119 eligible articles, 73 were further excluded after full text reading (number of failures not available or calculable, only pediatric population). A manual search in the bibliographic references did not find additional eligible articles.

Study Characteristics

After the selection process,

Discussion

ICSFS insertion is one of the most commonly performed neurosurgical procedures; an often life-saving simple mechanical treatment for a multifactorial complex disease. Although effective in the hydrocephalus treatment, it has been consistently associated with high rates of hardware-related complications and, thus, surgical revision. Despite being a significant neurosurgical concern, no attempt of a precise estimation of ICSFS overall failure rate has ever been reported. One of the several

Conclusions

Despite being a simple neurosurgical procedure, ICSFS insertion has one of the highest risk of complications, particularly failure. Despite ongoing apparent medical, surgical, and technical progress, the rate of infection has not significantly decreased over the past 30 years.

Acknowledgments

We are grateful to Segolene Van Outheusden for manuscript review, English proofreading, and a grammar and spelling check.

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