Management of shunt infections: a multicenter pilot study

Cerebrospinal Fluid Shunt Infections

Cerebrospinal fluid (CSF) shunt infections are a particularly challenging clinical problem. This review article addresses epidemiology and microbiology of CSF shunt infections. Clinical care is reviewed in detail, including recent guidelines and systematic review articles. Finally, current research into prevention and treatment is highlighted, with a discussion on the mechanisms of infection.

Implementation of an adapted perioperative ventriculoperitoneal shunting protocol in a tertiary center located in a low-to-middle-income country

OBJECTIVE

Preventative protocols have efficaciously reduced shunt infection in developed countries. However, the generalizability of these protocols in low-to-middle-income countries (LMICs) remains unclear. Previously, shunt insertion in the authors' center was routinely performed under institutional preventative precautions, which was updated via merging with the Hydrocephalus Clinical Research Network (HCRN) protocol. This study aimed to investigate the ventriculoperitoneal shunt (VPS) infection rates in pediatric patients following the implementation of the adapted protocol.

METHODS

The adapted protocol was implemented in all first-time VPS implantations between 2011 and 2021. The primary outcome was a 6-month shunt infection. The Pearson chi-square test was used for categorical variables and the Mann-Whitney U-test for numeric variables to evaluate the correlation with shunt infection.

RESULTS

A total of 352 first-time VPS procedures were performed adhering to the adapted protocol. The median age was 5 months, and 189 (53.7%) were male. Overall, 37 patients (10.5%) experienced shunt infection, with 30 (8.5%) occurring within the first 6 months, which was lower than 13.3% infection rate of the previous series of the same center. The infection rate was slightly higher than the 5.7% and 6.0% rates reported by HCRN studies. Patients with shunt infection were significantly younger (7.5 versus 17.5 months, P < 0.001).

CONCLUSIONS

This study validates the efficacy of an adapted perioperative protocol in mitigating shunt infection in a high-volume center in a LMIC. Adhering to a step-by-step protocol, modified to suit the healthcare resources and financial constraints of LMICs, could maintain low shunt infection rates that are roughly comparable to those of centers in high-income countries.

Cerebrospinal Fluid Shunt Reinfection and Malfunction in Ecuadorian Children with Different Reshunting Criteria After Infection. "Is It Just One Shunt After Another?"

OBJECTIVE

There is no firm evidence regarding cerebrospinal fluid (CSF) shunt reimplantation after infection in the pediatric population. The purpose of this study was to compare different criteria and analyze new shunt failure.

METHODS

A cross-sectional retrospective multicenter study was performed over 6 years to study patients and each infected shunt at diagnosis, reimplantation, and after reimplantation. The patients were divided into 2 groups: group 1 (G1), reimplantation after negative serial CSF cultures during antibiotic treatment; group 2 (G2), reimplantation after negative serial pancultures after completion of antibiotics. The differences were measured with Mann-Whitney and Χ2 tests; multivariate analysis and associations were calculated using odds ratios (ORs) based on logistic regression.

RESULTS

There were 137 shunt infection events in 110 patients: 28 events in G1 and 109 in G2. Significant differences were observed in the diagnosis and reimplantation. Reimplantation dysfunction in G1 was 16 (55.17%) versus 30 (27.78%) in G2 (P = 0.006). The risk of shunt malfunction after reimplantation increased for G1 reimplantation criteria (P = 0.018; OR, 3.34; confidence interval [CI], 1.23-9.05): pleocytosis at diagnosis >17 cells (P = 0.036; OR, 2.41; CI, 1.06-5.47), CSF proteins at diagnosis >182 mg/dL (P = 0.049; OR, 2.21; CI, 1.00-4.89).

CONCLUSIONS

G2 reimplantation criteria were related to improved pleocytosis, CSF proteins, and blood neutrophils compared with G1. Mechanical and infectious dysfunction of the new shunt was 3 times more prevalent in G1 than in G2, considering the differences between the groups at diagnosis. Increased parameters of infection at diagnosis were associated with future malfunction more than parameters before reimplantation in both groups.

Surgical treatment of post-infectious hydrocephalus in infants

The management of post-infective hydrocephalus in infants remains a challenging task for the pediatric neurosurgeon. The decision-making curve is often complex in that appropriate temporizing measures need to be implemented to properly clear any infection within the CSF before any decision can be made regarding a permanent solution. The etiology differs at varying stages of neonatal development, and the weight of the child, skin fragility, and relevant surgical treatment options are often important limiting factors. Deciding on the optimal treatment option involves assessing the etiology, age, and clinical and radiological features of the individual case and selecting the most appropriate surgical option.

Molecular Characterization of Microbiota in Cerebrospinal Fluid From Patients With CSF Shunt Infections Using Whole Genome Amplification Followed by Shotgun Sequencing

Understanding the etiology of cerebrospinal fluid (CSF) shunt infections and reinfections requires detailed characterization of associated microorganisms. Traditionally, identification of bacteria present in the CSF has relied on culture methods, but recent studies have used high throughput sequencing of 16S rRNA genes. Here we evaluated the method of shotgun DNA sequencing for its potential to provide additional genomic information. CSF samples were collected from 3 patients near the beginning and end of each of 2 infection episodes. Extracted total DNA was sequenced by: (1) whole genome amplification followed by shotgun sequencing (WGA) and (2) high-throughput sequencing of the 16S rRNA V4 region (16S). Taxonomic assignments of sequences from WGA and 16S were compared with one another and with conventional microbiological cultures. While classification of bacteria was consistent among the 3 approaches, WGA provided additional insights into sample microbiological composition, such as showing relative abundances of microbial versus human DNA, identifying samples of questionable quality, and detecting significant viral load in some samples. One sample yielded sufficient non-human reads to allow assembly of a high-quality Staphylococcus epidermidis genome, denoted CLIMB1, which we characterized in terms of its MLST profile, gene complement (including putative antimicrobial resistance genes), and similarity to other annotated S. epidermidis genomes. Our results demonstrate that WGA directly applied to CSF is a valuable tool for the identification and genomic characterization of dominant microorganisms in CSF shunt infections, which can facilitate molecular approaches for the development of better diagnostic and treatment methods.

Technology-Dependent Children

There are a growing number of medically complex children with implanted devices. Emergency physicians with a basic knowledge of these devices can troubleshoot and fix many of the issues that may arise. Recognition of malfunction of these devices can reduce morbidity and mortality among this special population. In this article, we review common issues that may arise in children with gastrostomy tubes, central nervous system shunts, cochlear implants, and vagal nerve stimulators.

Characterization of cerebrospinal fluid (CSF) microbiota from patients with CSF shunt infection and reinfection using high throughput sequencing of 16S ribosomal RNAgenes

BACKGROUND

Nearly 20% of patients with cerebrospinal fluid (CSF) shunt infection develop reinfection. It is unclear whether reinfections are caused by an organism previously present or are independent infection events.

OBJECTIVE

We used bacterial culture and high throughput sequencing (HTS) of 16S ribosomal RNA (rRNA) genes to identify bacteria present in serial CSF samples obtained from children who failed CSF shunt infection treatment. We hypothesized that organisms that persist in CSF despite treatment would be detected upon reinfection.

DESIGN/METHODS

Serial CSF samples were obtained from 6 patients, 5 with 2 infections and 1 with 3 infections; the study was limited to those for which CSF samples were available from the end of infection and beginning of reinfection. Amplicons of the 16S rRNA gene V4 region were sequenced. Taxonomic assignments of V4 sequences were compared with bacterial species identified in culture.

RESULTS

Seven infection dyads averaging 13.5 samples per infection were analyzed. A median of 8 taxa [interquartile range (IQR) 5-10] were observed in the first samples from reinfection using HTS. Conventional culture correlated with high abundance of an organism by HTS in all but 1 infection. In 6 of 7 infection dyads, organisms identified by culture at reinfection were detected by HTS of culture-negative samples at the end of the previous infection. The median Chao-Jaccard abundance-based similarity index for matched infection pairs at end of infection and beginning of reinfection was 0.57 (IQR 0.07-0.87) compared to that for unmatched pairs of 0.40 (IQR 0.10-0.60) [p = 0.46].

CONCLUSION(S)

HTS results were generally consistent with culture-based methods in CSF shunt infection and reinfection, and may detect organisms missed by culture at the end of infection treatment but detected by culture at reinfection. However, the CSF microbiota did not correlate more closely within patients at the end of infection and beginning of reinfection than between any two unrelated infections. We cannot reject the hypothesis that sequential infections were independent.

Treatment strategies for cerebrospinal shunt infections: a systematic review of observational studies

OBJECTIVE

A systematic review was conducted of studies comparing time to cerebrospinal fluid (CSF) sterilisation or rate of recurrence with different treatment strategies for CSF shunt infections.

METHODS

A librarian-directed search was conducted of Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid Medline Daily and Ovid Medline, Ovid Embase, Wiley Cochrane Library, CINAHL Plus with Full Text via EBSCOhost, Scopus Advanced Search, and Web of Science Core Collection from 1990 to May 2019. Studies of any design that compared outcomes in groups of any age with different management strategies were included. Studies that compared complete versus incomplete shunt removal were excluded. Quality assessment was performed with the Newcastle-Ottawa Scale.

RESULTS

The search identified 2208 records, of which 8 met the inclusion criteria. All were cohort studies of moderate quality. Four studies compared the duration of antibiotics; none demonstrates that a longer course prevented recurrences. Two studies analysed addition of rifampin, with one showing a decrease in recurrences while the other had a small sample size. No studies analysed the addition of intraventricular antibiotics, but one showed equally good results with once versus twice daily administration. One study reported no difference in recurrences with placement of antibiotic-impregnated catheters. Recurrence rates did not differ with shunt replacement minimum of 7 days vs less than 7 days after CSF became sterile. There were no recurrences in either group when shunt replacement was performed after sterile CSF cultures were obtained at 24 vs 48 hours after antibiotics were discontinued. A new shunt entry site did not decrease recurrences.

DISCUSSION

The main limitations are the lack of high-quality studies, the small sample sizes and the heterogeneity which precluded meta-analysis. Addition of rifampin for staphylococcal infections may decrease relapse but requires further study.

Prevención y tratamiento de las infecciones del sitio operatorio en neurocirugía. Estado del arte

El manejo adecuado de las infecciones del sitio operatorio (ISO) en neurocirugía es fundamental para la disminución de la carga de morbilidad y mortalidad en estos pacientes. La sospecha y confirmación diagnóstica asociadas al aislamiento microbiológico son esenciales para asegurar el tratamiento oportuno y el adecuado gerenciamiento de antibióticos. En esta revisión se presenta de forma resumida los puntos fundamentales para la prevención y el tratamiento de infecciones del sitio operatorio en neurocirugía y se incluye un apartado sobre el uso de antibióticos intratecales/intraventriculares.

Linezolid for the treatment of postneurosurgical infection caused by methicillin-resistant Staphylococcus

Background

Postneurosurgical infection (PNSI) is a major problem. Linezolid is a bacteriostatic oxazolidinone antibiotic with a highly activity against Gram-positive cocci resistant to methicillin and a good cerebrospinal fluid penetration. The purpose of this study is to evaluate the efficacy of linezolid in the treatment of PNSI caused by methicillin-resistant Staphylococcus (MRS).

Methods

We conducted an observational study for all patients over 14 years old and diagnosed with MRS PNSI. Demographic, clinical, and laboratory information were collected prospectively.

Results

A total of 10 patients with PNSI (6 meningitis, 2 ventriculitis, and 2 subdural empyema) received linezolid. MRS isolated was Staphylococcus aureus in seven cases and Staphylococcus epidermidis in three cases. All isolated microorganisms were susceptible to vancomycin (minimum inhibitory concentration (MIC) = 2 mg/L) and linezolid (MIC = 1). The rate of microbiologic efficacy was 100% for patients with meningitis or ventriculitis. In the case of subdural empyema, focal infection had improved between 14 and 18 days. No adverse effects occurred during this study.

Conclusion

Our results suggest that linezolid as an alternative to vancomycin for the treatment of PNSI caused by MRS with a high rate of efficacy.

Shunt infections: a review and analysis of a personal series

INTRODUCTION AND PURPOSE

CSF diversion shunts are notoriously prone to complications. The most difficult to manage among them is shunt infection, which warrants a prolonged hospital stay. The aim of this paper is to review the pattern of infections, the pathology, and management of shunt infections with special reference to a tertiary pediatric center in a developing country.

MATERIALS AND METHODS

This is a review of shunt infections in general and a retrospective study of all cases operated in the hospital from 2000 to 2015.

RESULTS

The authors analyze the data and try to discern patterns, which may enable newer interventions to treat as well as decrease the burden of shunt infections in the future.

CONCLUSION

It is difficult to determine the true incidence of shunt infections as there is no definition of what constitutes a shunt infection. There are no standardized international guidelines as to how to deal with an infected shunt. Though the ability to treat shunt infection has improved and the incidence of shunt infection has decreased over time, there is still no consensus on the best way to manage it. The prevention is predominantly based on common sense and has helped but a more scientific algorithm is the need of the hour.

Patient and Treatment Characteristics by Infecting Organism in Cerebrospinal Fluid Shunt Infection

BACKGROUND

Previous studies of cerebrospinal fluid (CSF) shunt infection treatment have been limited in size and unable to compare patient and treatment characteristics by infecting organism. Our objective was to describe variation in patient and treatment characteristics for children with first CSF shunt infection, stratified by infecting organism subgroups outlined in the 2017 Infectious Disease Society of America's (IDSA) guidelines.

METHODS

We studied a prospective cohort of children <18 years of age undergoing treatment for first CSF shunt infection at one of 7 Hydrocephalus Clinical Research Network hospitals from April 2008 to December 2012. Differences between infecting organism subgroups were described using univariate analyses and Fisher's exact tests.

RESULTS

There were 145 children whose infections were diagnosed by CSF culture and addressed by IDSA guidelines, including 47 with Staphylococcus aureus, 52 with coagulase-negative Staphylococcus, 37 with Gram-negative bacilli, and 9 with Propionibacterium acnes. No differences in many patient and treatment characteristics were seen between infecting organism subgroups, including age at initial shunt, gender, race, insurance, indication for shunt, gastrostomy, tracheostomy, ultrasound, and/or endoscope use at all surgeries before infection, or numbers of revisions before infection. A larger proportion of infections were caused by Gram-negative bacilli when antibiotic-impregnated catheters were used at initial shunt placement (12 of 23, 52%) and/or subsequent revisions (11 of 23, 48%) compared with all other infections (9 of 68 [13%] and 13 of 68 [19%], respectively). No differences in reinfection were observed between infecting organism subgroups.

CONCLUSIONS

The organism profile encountered at infection differs when antibiotic-impregnated catheters are used, with a higher proportion of Gram-negative bacilli. This warrants further investigation given increasing adoption of antibiotic-impregnated catheters.

Reinfection after treatment of first cerebrospinal fluid shunt infection: a prospective observational cohort study

OBJECTIVE CSF shunt infection requires both surgical and antibiotic treatment. Surgical treatment includes either total shunt removal with external ventricular drain (EVD) placement followed by new shunt insertion, or distal shunt externalization followed by new shunt insertion once the CSF is sterile. Antibiotic treatment includes the administration of intravenous antibiotics. The Hydrocephalus Clinical Research Network (HCRN) registry provides a unique opportunity to understand reinfection following treatment for CSF shunt infection. This study examines the association of surgical and antibiotic decisions in the treatment of first CSF shunt infection with reinfection. METHODS A prospective cohort study of children undergoing treatment for first CSF infection at 7 HCRN hospitals from April 2008 to December 2012 was performed. The HCRN consensus definition was used to define CSF shunt infection and reinfection. The key surgical predictor variable was surgical approach to treatment for CSF shunt infection, and the key antibiotic treatment predictor variable was intravenous antibiotic selection and duration. Cox proportional hazards models were constructed to address the time-varying nature of the characteristics associated with shunt surgeries. RESULTS Of 233 children in the HCRN registry with an initial CSF shunt infection during the study period, 38 patients (16%) developed reinfection over a median time of 44 days (interquartile range [IQR] 19-437). The majority of initial CSF shunt infections were treated with total shunt removal and EVD placement (175 patients; 75%). The median time between infection surgeries was 15 days (IQR 10-22). For the subset of 172 infections diagnosed by CSF culture, the mean ± SD duration of antibiotic treatment was 18.7 ± 12.8 days. In all Cox proportional hazards models, neither surgical approach to infection treatment nor overall intravenous antibiotic duration was independently associated with reinfection. The only treatment decision independently associated with decreased infection risk was the use of rifampin. While this finding did not achieve statistical significance, in all 5 Cox proportional hazards models both surgical approach (other than total shunt removal at initial CSF shunt infection) and nonventriculoperitoneal shunt location were consistently associated with a higher hazard of reinfection, while the use of ultrasound was consistently associated with a lower hazard of reinfection. CONCLUSIONS Neither surgical approach to treatment nor antibiotic duration was associated with reinfection risk. While these findings did not achieve statistical significance, surgical approach other than total removal at initial CSF shunt infection was consistently associated with a higher hazard of reinfection in this study and suggests the feasibility of controlling and standardizing the surgical approach (shunt removal with EVD placement). Considerably more variation and equipoise exists in the duration and selection of intravenous antibiotic treatment. Further consideration should be given to the use of rifampin in the treatment of CSF shunt infection. High-quality studies of the optimal duration of antibiotic treatment are critical to the creation of evidence-based guidelines for CSF shunt infection treatment.

2017 Infectious Diseases Society of America's Clinical Practice Guidelines for Healthcare-Associated Ventriculitis and Meningitis

The Infectious Diseases Society of America (IDSA) Standards and Practice Guidelines Committee collaborated with partner organizations to convene a panel of 10 experts on healthcare-associated ventriculitis and meningitis. The panel represented pediatric and adult specialists in the field of infectious diseases and represented other organizations whose members care for patients with healthcare-associated ventriculitis and meningitis (American Academy of Neurology, American Association of Neurological Surgeons, and Neurocritical Care Society). The panel reviewed articles based on literature reviews, review articles and book chapters, evaluated the evidence and drafted recommendations. Questions were reviewed and approved by panel members. Subcategories were included for some questions based on specific populations of patients who may develop healthcare-associated ventriculitis and meningitis after the following procedures or situations: cerebrospinal fluid shunts, cerebrospinal fluid drains, implantation of intrathecal infusion pumps, implantation of deep brain stimulation hardware, and general neurosurgery and head trauma. Recommendations were followed by the strength of the recommendation and the quality of the evidence supporting the recommendation. Many recommendations, however, were based on expert opinion because rigorous clinical data are not available. These guidelines represent a practical and useful approach to assist practicing clinicians in the management of these challenging infections.

Variability in Management of First Cerebrospinal Fluid Shunt Infection: A Prospective Multi-Institutional Observational Cohort Study

OBJECTIVES

To describe the variation in approaches to surgical and antibiotic treatment for first cerebrospinal fluid (CSF) shunt infection and adherence to Infectious Diseases Society of America (IDSA) guidelines.

STUDY DESIGN

We conducted a prospective cohort study of children undergoing treatment for first CSF infection at 7 Hydrocephalus Clinical Research Network hospitals from April 2008 through December 2012. Univariate analyses were performed to describe the study population.

RESULTS

A total of 151 children underwent treatment for first CSF shunt-related infection. Most children had undergone initial CSF shunt placement before the age of 6 months (n =  98, 65%). Median time to infection after shunt surgery was 28 days (IQR 15-52 days). Surgical management was most often shunt removal with interim external ventricular drain placement, followed by new shunt insertion (n = 122, 81%). Median time from first negative CSF culture to final surgical procedure was 14 days (IQR 10-21 days). Median duration of intravenous (IV) antibiotic use duration was 19 days (IQR 12-28 days). For 84 infections addressed by IDSA guidelines, 7 (8%) met guidelines and 61 (73%) had longer duration of IV antibiotic use than recommended.

CONCLUSIONS

Surgical treatment for infection frequently adheres to IDSA guidelines of shunt removal with external ventricular drain placement followed by new shunt insertion. However, duration of IV antibiotic use in CSF shunt infection treatment was consistently longer than recommended by the 2004 IDSA guidelines.

Hydrogel-coated ventricular catheters for high-risk patients receiving ventricular peritoneum shunt

Shunt infection is a morbid complication of cerebrospinal fluid (CSF) shunting. The catheters with a hydrophilic surface may impede bacterial adherence and thereby reduce catheter-related CSF infection.A retrospective study compared the occurrence of CSF infection related to use of either standard silastic catheters or hydrogel-coated ventricular catheters (Bioglide, Medtronic). The enrolment was available to neurosurgery patients undergoing shunt surgery from October 2012 to 2015 in two centers. The follow-up period was more than months.A total of 78 patients were included in the study. In 33 patients 35-cm hydrogel-coated ventricular peritoneum shunts (VPS) were used, and in remaining 45 patients 35-cm standard silastic VPS catheters were used. Infection occurred in 14 (17.9%) patients, including definite VPS-related CSF infection in 6 patients (7.7%) and probable infection in remaining 8 patients (10.3%). There was a significant difference found in patients with total infection between the two groups [RR (95% CI); 0.200 (0.050-0.803), P = 0.014]. Analysis of Kaplan-Meier curve estimates indicated significant statistical difference between the two catheter types in duration (log rank = 4.204, P < 0.05). Significant statistical differences were also found in the subgroups including previous CSF infection within 1 month (log rank = 4.391, P = 0.04), conversion of external ventricular drains to shunt (Log Rank = 4.520, P = 0.03), and hospital stay >1 month (log rank = 5.252, P = 0.02). There was no difference found between the two groups of the patients with other infections within 1 month. The follow-up period was of 36 months.The hydrogel-coated catheter is a safe and related to lower infection rates for high-risk patients who underwent shunt surgery.

Antibiotic duration and timing of the switch from intravenous to oral route for bacterial infections in children: systematic review and guidelines

Few studies are available to inform duration of intravenous antibiotics for children and when it is safe and appropriate to switch to oral antibiotics. We have systematically reviewed antibiotic duration and timing of intravenous to oral switch for 36 paediatric infectious diseases and developed evidence-graded recommendations on the basis of the review, guidelines, and expert consensus. We searched databases and obtained information from references identified and relevant guidelines. All eligible studies were assessed for quality. 4090 articles were identified and 170 studies were included. Evidence relating antibiotic duration to outcomes in children for some infections was supported by meta-analyses or randomised controlled trials; in other infections data were from retrospective series only. Criteria for intravenous to oral switch commonly included defervescence and clinical improvement with or without improvement in laboratory markers. Evidence suggests that intravenous to oral switch can occur earlier than previously recommended for some infections. We have synthesised recommendations for antibiotic duration and intravenous to oral switch to support clinical decision making and prospective research.

Prevention and management of internal cerebrospinal fluid shunt infections

Cerebrospinal fluid (CSF) shunt infection is a serious and potentially devastating complication of CSF shunt placement. Younger age, previous CSF shunt infection or revision, and the type of the shunt are important risk factors for shunt infection. More than half of the cases are caused by Staphylococcus aureus and coagulase-negative staphylococci. The biofilm plays a central role in its pathogenesis. CSF cultures remain the gold standard for diagnosis of CSF shunt infection. The most effective way to prevent CSF shunt infection is optimization of sterile protocols and use of proper and timely antibiotic prophylaxis. Management of CSF shunt infection frequently requires removal of all shunt components, placement of a temporary external device, and administration of intravenous antibiotics, followed by reshunting at a later time. This review summarizes and analyses the results of previous reports of CSF shunt infection and assesses the prevention and management of this important entity.

Reduction in CSF shunt infection over a 10-year period associated with the application of concentrated topical antibiotic powder directly to surgical wounds prior to closure

OBJECT

The application of concentrated topical antibiotic powder directly to surgical wounds has been associated with a reduction in wound infection in cardiac, spinal, and deep brain stimulator surgery. As a result of these findings, the corresponding author began systematically applying concentrated bacitracin powder directly to wounds during shunt surgery more than 5 years ago. The object of this study was to evaluate the effectiveness of concentrated bacitracin powder applied directly to wounds prior to closure during cranial shunt surgery and to evaluate the association between shunt infection and other risk factors. A single surgeon's cranial shunt surgery experience, equally divided between periods during which antibiotic powder was and was not applied, was studied to assess the effect of concentrated bacitracin powder application on shunt infection rates.

METHODS

This retrospective cohort study included all patients who underwent a cranial shunting procedure at All Children's Hospital performed by a single surgeon (G.F.T.) from 2001 to 2013. The surgeon applied bacitracin powder to all shunt wounds prior to closure between 2008 and 2013, whereas no antibiotic powder was applied to wounds prior to 2008. Both initial and revision shunting procedures were included, and all procedures were performed at a large children's hospital (All Children's Hospital). The primary outcome measure was shunt infection, which was defined using clinical criteria previously used by the Hydrocephalus Clinical Research Network. The association between bacitracin powder use and shunt infection was estimated using hazard ratios (HRs) and 95% CIs from Cox proportional hazard regression models.

RESULTS

A total of 47 infections out of 539 shunt operations occurred during the study period, resulting in an overall infection rate of 8.7%. Procedures performed before the use of concentrated bacitracin powder was instituted resulted in a 13% infection rate, whereas procedures performed after systematic use of bacitracin powder had been adopted experienced a 1% infection rate. Bacitracin powder use was associated with a reduced risk of shunt infection in univariate analysis (HR 0.11, 95% CI 0.03-0.34, p = 0.0002) and also in multivariate analysis (HR 0.12, 95% CI 0.04-0.41, p = 0.0006) when controlling for covariates that were associated with infection from the univariate analysis. The presence of a tracheostomy or a gastrostomy tube was also found to be independently associated with shunt infection in multivariate analysis (HR 3.15, 95% CI 1.05-9.50, p = 0.04, and HR 2.82, 95% CI 1.33-5.96, p = 0.007, respectively).

CONCLUSIONS

This study suggests, for the first time, that the systematic application of concentrated bacitracin powder to surgical wounds prior to closure during shunt surgery may be associated with a reduction in cranial shunt infection. This initial finding requires validation in a large prospective study before widespread application can be advocated.

An investigation into the vancomycin concentration in the cerebrospinal fluid due to vancomycin intraventricular administration in newborns: a study of 13 cases

Treatment against shunt infection by transvenous antimicrobial treatment is difficult, with a high risk of relapse. Consequently, to maintain a sufficient cerebrospinal fluid (CSF) concentration, intraventricular administration is utilized in combination with the transvenous administration of vancomycin (VCM). Few studies have so far investigated the optimum administration dose for newborns and the concentration in the CSF. Therefore, we chronologically measured the VCM concentration in the CSF after VCM intraventricular administration in newborns and attempted to elucidate the optimum administration method.The participants consisted of newborns admitted to Juntendo University Neonatal intensive care unit from March 2007 to June 2011 who underwent interventricular shunting placement. VCM was intraventricularly administered to 10 patients for a total of 13 cases. The CSF concentration of VCM was chronologically measured at 12 to 120  hours following the intraventricular administration of VCM.The intraventricular administration groups with VCM of 20 (n = 6) and 10  mg (n = 2) had a high concentration in the CSF at 24  hours following administration (95-168  mg/L), with the concentration remaining high at 72  hours (13.2-72  mg/L). At the same time, in the 5  mg group (n = 5), the concentration in the CSF 24  hours following VCM administration was sufficiently maintained (33.2-62.9  mg/L), with a sufficient trough concentration still maintained at 72  hours (11.7-16.5  mg/L).The concentration in the CSF is prolonged in newborns, thus allowing a sufficient therapeutic range to be maintained even at an intraventricular administration of 5  mg. It is therefore believed that the monitoring of the CSF is very important regarding the administration interval because the VCM concentration in the CSF differs depending on the case.

Analysis of the potential risk of central intravenous lines and/or total parenteral nutrition with ventriculoatrial shunts

OBJECT

The distal catheter of a ventriculoatrial (VA) cerebrospinal fluid shunt is potentially exposed to bacterial seeding from a subclavian central line. The risk of blood stream infections (BSIs) from central lines increases with administration of total parenteral nutrition (TPN). The potential risks of shunt malfunction or infection in patients with a VA shunt and a concurrent subclavian central line and/or TPN administration have not been studied.

METHODS

A retrospective review of 49 pediatric patients with placement of a VA shunt was performed. Three outcome measures were studied: shunt malfunction, shunt infection, and bacteremia/fungemia requiring shunt removal. All outcomes were measured by 1 year after shunt insertion. We analyzed the following potential risk factors: age at shunt insertion, prior ventriculoperitoneal (VP) shunt, prior shunt infection, abdominal infection/necrotizing enterocolitis (NEC), concurrent subclavian central line, and administration of TPN. The association between each risk factor and outcome was evaluated using Fisher's exact test to generate the relative risk. Additionally, a logistic regression analysis was performed to evaluate the odds ratio of the outcomes to risk factors considering age as a covariate.

RESULTS

The average age at shunt insertion was 6.3 ± 7.6 years. The most common diagnosis was posthemorrhagic hydrocephalus of prematurity (53.1 %). Fifteen patients (30.1 %) had a shunt malfunction within 1 year, 6 (12.2 %) had a shunt infection, and 3 (6.1 %) required removal of the shunt due to bacteremia/fungemia. The age at shunt insertion was not a statistically significant independent risk factor for any of the three outcomes. Prior shunt infection predicted an increased risk for both future shunt malfunction and infection in both the associative relative risk analysis and the age-dependent logistic regression analysis, although the correlation did not reach statistical significance. The presence of a subclavian central line or TPN administration did not statistically increase the risk over baseline for any of the outcomes in either analysis.

CONCLUSIONS

The relatively small number of patients limits the power of the study. Considering this limitation, the data suggests that the presence of a concurrent subclavian central line or administration of TPN does not increase the risk of shunt malfunction or infection over the baseline of this high-risk cohort.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 8: Management of cerebrospinal fluid shunt infection

OBJECT

The objective of this systematic review was to answer the following question: What is the optimal treatment strategy for CSF shunt infection in pediatric patients with hydrocephalus?

METHODS

The US National Library of Medicine and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to the objective of this systematic review. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected and graded according to their quality of evidence (Classes I-III). Evidentiary tables were constructed that summarized pertinent study results, and based on the quality of the literature, recommendations were made (Levels I-III).

RESULTS

A review and critical appraisal of 27 studies that met the inclusion criteria allowed for a recommendation for supplementation of antibiotic treatment using partial (externalization) or complete shunt hardware removal, with a moderate degree of clinical certainty. However, a recommendation regarding whether complete shunt removal is favored over partial shunt removal (that is, externalization) could not be made owing to severe methodological deficiencies in the existing literature. There is insufficient evidence to recommend the use of intrathecal antibiotic therapy as an adjunct to systemic antibiotic therapy in the management of routine CSF shunt infections. This also holds true for other clinical scenarios such as when an infected CSF shunt cannot be completely removed, when a shunt must be removed and immediately replaced in the face of ongoing CSF infection, or when the setting is ventricular shunt infection caused by specific organisms (for example, gram-negative bacteria).

CONCLUSIONS

Supplementation of antibiotic treatment with partial (externalization) or complete shunt hardware removal are options in the management of CSF shunt infection. There is insufficient evidence to recommend either shunt externalization or complete shunt removal as the preferred surgical strategy for the management of CSF shunt infection. Therefore, clinical judgment is required. In addition, there is insufficient evidence to recommend the combination of intrathecal and systemic antibiotics for patients with CSF shunt infection when the infected shunt hardware cannot be fully removed, when the shunt must be removed and immediately replaced, or when the CSF shunt infection is caused by specific organisms. The potential neurotoxicity of intrathecal antibiotic therapy may limit its routine use.

RECOMMENDATION

Supplementation of antibiotic treatment with partial (externalization) or with complete shunt hardware removal is an option in the management of CSF shunt infection.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty.

RECOMMENDATION

There is insufficient evidence to recommend either shunt externalization or complete shunt removal as a preferred surgical strategy for the management of CSF shunt infection. Therefore, clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

RECOMMENDATION

There is insufficient evidence to recommend the combination of intrathecal and systemic antibiotics for patients with CSF shunt infection in whom the infected shunt hardware cannot be fully removed or must be removed and immediately replaced, or when the CSF shunt infection is caused by specific organisms. The potential neurotoxicity of intrathecal antibiotic therapy may limit its routine use.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

Risk factors for first cerebrospinal fluid shunt infection: findings from a multi-center prospective cohort study

OBJECTIVE

To quantify the extent to which cerebrospinal fluid (CSF) shunt revisions are associated with increased risk of CSF shunt infection, after adjusting for patient factors that may contribute to infection risk.

STUDY DESIGN

We used the Hydrocephalus Clinical Research Network registry to assemble a large prospective 6-center cohort of 1036 children undergoing initial CSF shunt placement between April 2008 and January 2012. The primary outcome of interest was first CSF shunt infection. Data for initial CSF shunt placement and all subsequent CSF shunt revisions prior to first CSF shunt infection, where applicable, were obtained. The risk of first infection was estimated using a multivariable Cox proportional hazard model accounting for patient characteristics and CSF shunt revisions, and is reported using hazard ratios (HRs) with 95% CI.

RESULTS

Of the 102 children who developed first infection within 12 months of placement, 33 (32%) followed one or more CSF shunt revisions. Baseline factors independently associated with risk of first infection included: gastrostomy tube (HR 2.0, 95% CI, 1.1, 3.3), age 6-12 months (HR 0.3, 95% CI, 0.1, 0.8), and prior neurosurgery (HR 0.4, 95% CI, 0.2, 0.9). After controlling for baseline factors, infection risk was most significantly associated with the need for revision (1 revision vs none, HR 3.9, 95% CI, 2.2, 6.5; ≥2 revisions, HR 13.0, 95% CI, 6.5, 24.9).

CONCLUSIONS

This study quantifies the elevated risk of infection associated with shunt revisions observed in clinical practice. To reduce risk of infection risk, further work should optimize revision procedures.

Few Patient, Treatment, and Diagnostic or Microbiological Factors, Except Complications and Intermittent Negative Cerebrospinal Fluid (CSF) Cultures During First CSF Shunt Infection, Are Associated With Reinfection

BACKGROUND

The relationship between first and subsequent cerebrospinal fluid (CSF) shunt infections is poorly understood. By understanding the factors associated with increased risk of reinfection, researchers may provide optimal treatment strategies at the time of first infection. The objective of this study was to describe and compare children with and without CSF shunt reinfection.

METHODS

A retrospective cohort study was performed among 118 children who underwent initial CSF shunt placement and developed first CSF shunt infection. The primary outcome variable was CSF shunt reinfection. Patient risk factors and medical and surgical management of initial CSF shunt placement and first CSF shunt infection were compared between children with and without reinfection.

RESULTS

Of 118 children with first infection, 31 (26%) developed a reinfection during the study period (overall median follow-up, 2096 days). Factors associated with reinfection in this cohort included ventriculoatrial or complex shunt at initial CSF shunt placement, complications after first CSF shunt infection, and intermittent negative CSF cultures.

CONCLUSIONS

Few patient or treatment factors were associated with reinfection. Factors associated with difficult-to-treat first CSF shunt infection, including complications after first CSF shunt infection and intermittent negative CSF cultures, were associated with reinfection. Clinicians who treat patients with unusual CSF shunts or more difficult first infections should have a high index of suspicion for reinfection after treatment is completed.

Evaluation of microbial bacterial and fungal diversity in cerebrospinal fluid shunt infection

Background

Cerebrospinal fluid shunt infection can be recalcitrant. Recurrence is common despite appropriate therapy for the pathogens identified by culture. Improved diagnostic and therapeutic approaches are required, and culture-independent molecular approaches to cerebrospinal fluid shunt infections have not been described.

Objectives

To identify the bacteria and fungi present in cerebrospinal fluid from children with cerebrospinal fluid shunt infection using a high-throughput sequencing approach, and to compare those results to those from negative controls and conventional culture.

Methods

This descriptive study included eight children ≤18 years old undergoing treatment for culture-identified cerebrospinal fluid shunt infection. After routine aerobic culture of each cerebrospinal fluid sample, deoxyribonucleic acid (DNA) extraction was followed by amplification of the bacterial 16S rRNA gene and the fungal ITS DNA region tag-encoded FLX-Titanium amplicon pyrosequencing and microbial phylogenetic analysis.

Results

The microbiota analyses for the initial cerebrospinal fluid samples from all eight infections identified a variety of bacteria and fungi, many of which did not grow in conventional culture. Detection by conventional culture did not predict the relative abundance of an organism by pyrosequencing, but in all cases, at least one bacterial taxon was detected by both conventional culture and pyrosequencing. Individual bacterial species fluctuated in relative abundance but remained above the limits of detection during infection treatment.

Conclusions

Numerous bacterial and fungal organisms were detected in these cerebrospinal fluid shunt infections, even during and after treatment, indicating diverse and recalcitrant shunt microbiota. In evaluating cerebrospinal fluid shunt infection, fungal and anaerobic bacterial cultures should be considered in addition to aerobic bacterial cultures, and culture-independent approaches offer a promising alternative diagnostic approach. More effective treatment of cerebrospinal fluid shunt infections is needed to reduce unacceptably high rates of reinfection, and this work suggests that one effective strategy may be reduction of the diverse microbiota present in infection.

Use of quantitative 16S rRNA PCR to determine bacterial load does not augment conventional cerebrospinal fluid (CSF) cultures among children undergoing treatment for CSF shunt infection

The aim of this study was to develop a quantitative 16S rRNA assay for determination of bacterial nucleic acid load in cerebrospinal fluid (CSF) shunt infection and to compare quantitative 16S rRNA polymerase chain reaction (PCR) findings to those of conventional bacterial culture in patients treated for CSF shunt infection. We developed a quantitative 16S rRNA PCR assay that detected bacterial load across a range of 2.5 × 10(9) down to 2.5 × 10(4) 16S copies/mL CSF under experimental conditions for numerous Gram-positive and Gram-negative organisms. However, when applied to archived CSF samples from 25 shunt infection episodes, correlations between positive bacterial culture and 16S rRNA levels were seen in only half of infections, and 16S rRNA levels dropped precipitously after an initial peak on the first day of sample collection. Bacterial load measured using 16S rRNA PCR does not provide sufficient information beyond bacterial culture to inform CSF shunt infection treatment.

Shunt infection in the first year of life

OBJECT

Children younger than 1 year of age are unique in their physiology and comorbidities. Reports in the literature suggest that the risk factors for shunt infection may be different in this population compared with older children. Importantly, these infants often have other congenital malformations requiring various surgical interventions, which impose an additional risk of infection.

METHODS

In the 3-year period between 2008 and 2010, 270 patients underwent initial CSF shunt placement during the 1st year of life. Clinical characteristics, hospital course, and shunt infections were prospectively recorded in the practice and hospital electronic medical record. Special attention was given to types and timing of other invasive procedures and their relationship with shunt infection.

RESULTS

The average gestational age was 33.6 weeks, and the average birth weight was 2333 g. The average weight at the time of shunt insertion was 4281 g. Prior to shunt insertion, 120 patients underwent 148 surgical procedures, including ventricular access device insertion (n = 63), myelomeningocele closure (n = 37), and cardiac procedures (n = 11), among others. In the 12-month period after shunt insertion, 121 of the 270 patients underwent 135 surgical procedures, which included 79 CSF shunt revisions. Shunt infection occurred in 22 patients, and organisms were identified in 20 cases. Univariate analysis showed that of the very prematurely born infants (gestational age < 30 weeks), those who underwent preshunt cardiac surgery and any surgical procedures within 30 days after the shunt insertion were at a greater risk of shunt infection. In multivariate analysis, preshunt cardiac surgery and surgical procedures within 30 days postshunt placement were significant risk factors independent of gestational age, birth weight, and history of shunt revisions.

CONCLUSIONS

The results of this study suggest that surgical procedures within 30 days after shunt insertion and preshunt cardiac surgery are associated with a greater risk of shunt infection in children in whom these devices were inserted during the 1st year of life.

Recurrent cerebrospinal fluid shunt infection and the efficacy of reusing infected ventricular entry sites

OBJECT

The objective of this investigation was to review the clinical characteristics of recurrent CSF shunt infections in a large pediatric neurosurgical practice and to assess the safety and efficacy of reusing original ventricular entry sites for external ventricular drainage during treatment of infections and for subsequent reinsertion of shunts.

METHODS

Prospectively accrued clinical data on all patients treated at Children's Hospital Colorado for CSF shunt infections within a 10.5-year span were retrospectively investigated.

RESULTS

One hundred twenty-one consecutive cases of CSF shunt infection met inclusion criteria. Recurrent shunt infection attributable to the management of these infections occurred in 14 cases (11.6%). Three recurrent infections were with their original organisms, 7 were organisms different from the original organisms, and 4 were indeterminate.

CONCLUSIONS

Half or more of recurrent shunt infections were with organisms different from the original organism, and hence were new-type infections introduced during the management of the original infections. Incomplete eradication of original pathogens accounted for 3 (21.4%) of the 14 recurrent infections. Reusing recently infected or contaminated ventricular entry sites, both for CSF drainage during treatment and for implantation of new shunts, was as safe, with regard to risk of recurrent infection, as switching to new entry sites. Prior evidence of shunt infection is not, alone, a sufficient reason to change to a previously well-functioning site, and reuse of contaminated ventricular entry sites avoids all risks associated with making new ventricular entries.

Ventriculoperitoneal shunt failure: an institutional review of 2-year survival rates

PURPOSE

Prior research has examined predictors of shunt failure in children with hydrocephalus and concluded that the majority of shunts do not survive long-term. However, risk factors such as etiology, birth weight, and gestational age may vary across institutions and populations. We sought to identify the social, clinical, and neonatal factors associated with initial ventriculoperitoneal (VP) shunt failure in the intraventricular hemorrhage (IVH) patient population and the patient population with an etiology other than IVH (non-IVH).

METHODS

A retrospective review of patients, born during 2000-2005 diagnosed and treated for hydrocephalus at Children's of Alabama was conducted. Survival analysis identified factors associated with time to shunt failure.

RESULTS

Analyses were done separately for the IVH and non-IVH cohorts. Age and weight at initial VP shunt insertion were found to be associated with shunt failure in the non-IVH group (p < .05). Of the 238 patients in the non-IVH cohort, 108 failed within 2 years of their initial insertion. Fifty of those shunt failures occurred within 3 months of initial shunt placement. In the IVH cohort, 56 out of 100 failed within 2 years; 36 of those failed within 3 months post initial shunt insertion. When controlling for type of shunt failure, age at initial shunt placement was associated with time to shunt failure (p = .0004).

CONCLUSION

This study confirms previously published studies on the IVH population. A prospective cohort study and standardized clinical decision making are necessary to further assess the impact that shunting has on this patient population.

Incidence and risk factors of ventriculoperitoneal shunt infections in children: a study of 333 consecutive shunts in 6 years

The major aims of this study were to estimate the infection rate and recognize the risk factor for ventriculoperitoneal (VP) shunt infections in children. To analyze shunt infection rate and identify risk factors, a retrospective cohort analysis of 333 consecutive VP shunt series was performed at Seoul National University Children's Hospital in Korea between January 2005 and February 2011. Overall, 35 shunts (10.5%) were infected, which represented an infection rate of 0.075 infection cases per shunt per year. VP shunt infection occurred at a median of 1 month (range, 6 days to 8 months) after insertion. An independent risk factor for shunt infection was undergoing an operation before the first year of life (relative risk 2.31; 95% confidence interval, 1.19-4.48). The most common causative microorganism was coagulase-negative staphylococci in 16 (45.7%) followed by Staphylococcus aureus in 8 (22.9%). Methicillin resistance rate was 83.3% among coagulase-negative staphylococci and S. aureus. In this study, cerebrospinal fluid shunt infection rate was 10.5%. Infection was frequently caused by methicillin-resistant coagulase-negative staphylococci and S. aureus within two months after shunt surgery. Vancomycin may be considered as the preoperative prophylaxis for shunt surgery in a situation where methicillin resistance rate is very high.

Consensus definitions of complications for accurate recording and comparisons of surgical outcomes in pediatric neurosurgery

OBJECT

Monitoring and recording of complications in pediatric neurosurgery are important for quality assurance and in particular for improving outcomes. Lack of accurate or mutually agreed upon definitions hampers this process and makes comparisons between centers, which is an important method to improve outcomes, difficult. Therefore, the Canadian Pediatric Neurosurgery Study Group created definitions of complications in pediatric neurosurgery with consensus among 13 Canadian pediatric neurosurgical centers.

METHODS

Definitions of complications were extracted from randomized trials, prospective data collection studies, and the medical literature. The definitions were presented at an annual meeting and were subsequently recirculated for anonymous comment and revision, assembled by a third party, and re-presented to the group for consensus.

RESULTS

Widely used definitions of shunt failure were extracted from previous randomized trials and prospective studies. Definitions for wound infections were extracted from the definitions from the Centers for Disease Control and Prevention. Postoperative neurological deficits were based on the Pediatric Stroke Outcome Measure. Other definitions were created and modified by consensus. These definitions are now currently in use across the Canadian Pediatric Neurosurgery Study Group centers in Morbidity and Mortality data collection and for subsequent comparison studies.

CONCLUSIONS

Coming up with consensus definitions of complications in pediatric neurosurgery is a first step in improving the quality of outcomes. It is a dynamic process, and further refinements are anticipated. Center to center comparison will hopefully allow significant variations in outcomes to be identified and acted upon.

The use of the ASET in the diagnosis of ventriculoatrial shunt infection

A 38-year-old man with a ventriculoatrial shunt presented with non-specific symptoms (headache, back pain, night sweats) and inconclusive laboratory results. He showed an extremely high titre of antibody to Staphylococcus epidermidis which proved diagnostic of shunt infection. This was confirmed on shunt removal and he was successfully treated.

Revision surgeries are associated with significant increased risk of subsequent cerebrospinal fluid shunt infection

BACKGROUND

The object of this study was to determine whether cerebrospinal fluid (CSF) shunt revision(s) are associated with increased risk of CSF shunt infection, after adjusting for baseline factors that contribute to infection risk.

METHODS

This was a retrospective cohort study of 579 children aged 0-18 years who underwent initial CSF shunt placement between January 01, 1997 and October 12, 2006 at a tertiary care children's hospital. The outcome of interest was CSF shunt infection. Data for all subsequent CSF shunt revisions leading up to and including the initial CSF shunt infection, when applicable, were obtained. The likelihood of infection was determined using a Cox proportional hazard model accounting for patient characteristics and CSF shunt revisions, and is reported using hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

There were 123 children who developed infection. Baseline factors independently associated with hazard of infection included age 0 to <6 months at CSF shunt placement (HR 2.4, 95% CI: 1.02-6.7) and myelomeningocele (HR 0.4, 95% CI: 0.2-0.8). Controlling for baseline factors, the risk of infection after shunt revision was significantly greater than at the time of initial placement (HR 3.0, 95% CI: 1.9-4.7), and this risk increased as numbers of revisions increased (≥2 revisions HR 6.5, 95% CI: 3.6-11.4).

CONCLUSIONS

Although younger age is associated with increased hazard of infection, subsequent CSF shunt revision significantly increases infection risk.

Action of linezolid or vancomycin on biofilms in ventriculoperitoneal shunts in vitro

Cerebrospinal fluid (CSF) shunts used to treat hydrocephalus have an overall infection rate of about 10% of operations. The commonest causative bacteria are Staphylococcus epidermidis, followed by Staphylococcus aureus and enterococci. Major difficulties are encountered with nonsurgical treatment due to biofilm development in the shunt tubing and inability to achieve sufficiently high CSF drug levels by intravenous administration. Recently, three cases of S. epidermidis CSF shunt infection have been treated by intravenous linezolid without surgical shunt removal, and we therefore investigated vancomycin and linezolid against biofilms of these bacteria in vitro. A continuous-perfusion model of shunt catheter biofilms was used to establish mature (1-week) biofilms of Staphylococcus aureus, Staphylococcus epidermidis (both methicillin resistant [MRSA and MRSE]), Enterococcus faecalis, and Enterococcus faecium. They were then "treated" with either vancomycin or linezolid in concentrations achievable in CSF for 14 days. The biofilms were then monitored for 1 week for eradication and for regrowth. Enterococcal biofilms were not eradicated by either vancomycin or linezolid. Staphylococcal biofilms were eradicated by both antibiotics after 2 days and did not regrow. No resistance was seen. Linezolid at concentrations achievable by intravenous or oral administration was able to eradicate biofilms of both S. epidermidis (MRSE) and S. aureus (MRSA). Neither vancomycin at concentrations achievable by intrathecal administration nor linezolid was able to eradicate enterococcal biofilms. It is hoped that these in vitro results will stimulate further clinical trials with linezolid, avoiding surgical shunt removal.

Role of endoscopic third ventriculostomy at infected cerebrospinal fluid shunt removal

OBJECT

Cerebrospinal fluid shunt infection is distressing, especially in the pediatric population. Usually, infected CSF shunts are removed, and after temporary external CSF drainage, reinsertion of the CSF shunt is necessary. Unfortunately, it is not rare to encounter CSF reinfection after shunt renewal, and furthermore, the reinserted CSF shunt is at a considerable risk of malfunction. Endoscopic third ventriculostomy (ETV) is a potent option in managing CSF shunt infection, although ETV failure may occur more frequently when it is used to remove an infected shunt. The authors retrospectively evaluated CSF reinfection after using ETV during removal of infected CSF shunts; then the longevity of ETV and of successive reinserted ventriculoperitoneal shunts (VPSs) after ETV failure were also examined.

METHODS

Children with shunted hydrocephalus were retrospectively reviewed, and data on their initial CSF shunt infections were extracted. Thirty-six children underwent VPS reinsertion (the VPS group), and 9 underwent ETV after removal of the infected CSF shunt (the ETV group). As the primary outcome, ETV efficacy against CSF reinfection within 6 months was analyzed by comparing the reinfection rates, and the risk factors for CSF reinfection were analyzed by logistic regression. The longevity of the reinserted shunt in the VPS group was calculated using the Kaplan-Meier method, which was compared with ETV longevity as the secondary outcome, and also with the longevity of reinserted VPSs in the ETV group after ETV failure as the tertiary outcome.

RESULTS

Reinfection of CSF was seen in 27.8% of children in the VPS group. Among 9 children in the ETV group, only 1 (11.1%) had CSF reinfection. However, logistic regression analysis failed to show that performing ETV was a significant factor protecting against CSF reinfection: the significant risk factors were younger age at reinsertion of VPS or ETV (p = 0.037) and a history of shunt revisions (p = 0.011). The longevity of reinserted VPSs in the VPS group was calculated to be 658 ± 166.3 days (mean ± SE). Longevity of ETV was compared in the analysis of the secondary outcome, which was 929.2 ± 511.1 days, and there were no significant differences between these durations. Only 2 ETVs stayed patent, and a VPS was eventually implanted in the other 7 children. The longevity of this reinserted VPS in the ETV group, calculated based on these 7 children, was 2011.1 ± 540.7 days, which was confirmed to be longer than that in the VPS group (p = 0.031).

CONCLUSIONS

Although the protective effect of using ETV during removal of an infected CSF shunt on reinfection is marginal, the ETV longevity can be considered equivalent to that of reinserted VPSs. Even if ETV failure occurs, the reinserted VPS has significantly better longevity than a VPS reinserted without using ETV, and use of ETV during infected CSF shunt removal can be considered a potent alternative or at least an adjunct to VPS reinsertion.

Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis

OBJECT

Infection is a serious and costly complication of CSF shunt implantation. Antibiotic-impregnated shunts (AISs) were introduced almost 10 years ago, but reports on their ability to decrease the infection rate have been mixed. The authors conducted a meta-analysis assessing the extent to which AISs reduce the rate of shunt infection compared with standard shunts (SSs). They also examined cost savings to determine the degree to which AISs could decrease infection-related hospital expenses.

METHODS

After conducting a comprehensive search of multiple electronic databases to identify studies that evaluated shunt type and used shunt-related infection as the primary outcome, 2 reviewers independently evaluated study quality based on preestablished criteria and extracted data. A random effects meta-analysis of eligible studies was then performed. For studies that demonstrated a positive effect with the AIS, a cost-savings analysis was conducted by calculating the number of implanted shunts needed to prevent a shunt infection, assuming an additional cost of $400 per AIS system and $50,000 to treat a shunt infection.

RESULTS

Thirteen prospective or retrospective controlled cohort studies provided Level III evidence, and 1 prospective randomized study provided Level II evidence. "Shunt infection" was generally uniformly defined among the studies, but the availability and detail of baseline demographic data for the control (SS) and treatment (AIS) groups within each study were variable. There were 390 infections (7.0%) in 5582 procedures in the control group and 120 infections (3.5%) in 3467 operations in the treatment group, yielding a pooled absolute risk reduction (ARR) and relative risk reduction (RRR) of 3.5% and 50%, respectively. The meta-analysis revealed the AIS to be statistically protective in all studies (risk ratio = 0.46, 95% CI 0.33-0.63) and in single-institution studies (risk ratio = 0.38, 95% CI 0.25-0.58). There was some evidence of heterogeneity when studies were analyzed together (p = 0.093), but this heterogeneity was reduced when the studies were analyzed separately as single institution versus multiinstitutional (p > 0.10 for both groups). Seven studies showed the AIS to be statistically protective against infection with an ARR and RRR ranging from 1.7% to 14.2% and 34% to 84%, respectively. The number of shunt operations requiring an AIS to prevent 1 shunt infection ranged from 7 to 59. Assuming 200 shunt cases per year, the annual savings for converting from SSs to AISs ranged from $90,000 to over $1.3 million.

CONCLUSIONS

While the authors recognized the inherent limitations in the quality and quantity of data available in the literature, this meta-analysis revealed a significant protective benefit with AIS systems, which translated into substantial hospital savings despite the added cost of an AIS. Using previously developed guidelines on treatment, the authors strongly encourage the use of AISs in all patients with hydrocephalus who require a shunt, particularly those at greatest risk for infection.

Treatment and microbiology of repeated cerebrospinal fluid shunt infections in children

BACKGROUND

A small group of children have second and even more cerebrospinal fluid (CSF) shunt infections (SIs). We sought to describe the treatment approaches used for, and the microbiology of, repeated SIs.

METHODS

The study population included 31 children with second shunt infection (SI-2) among those undergoing initial CSF shunt placement and treatment for initial infection at Primary Children's Medical Center. CSF SI was defined as follows: (1) presence of bacteria in Gram stain and/or culture of CSF, wound, and/or pseudocyst; (2) visible hardware; (3) abdominal pseudocyst; or (4) presence of bacteria in a blood culture in children with a ventriculoatrial shunt. Infection rates were generated using per-patient denominators, and the concordance of organisms across infections was summarized.

RESULTS

Of the 31 children with SI-2, most were less than 6 months of age at initial shunt placement (81%), male (77%), and with ventriculoperitoneal shunts (71%). Of total, 18 developed SI-3 and 8 developed SI-4. Infection rates were 60% (95% confidence interval [CI]: 42%-75%, n = 18/30) for SI-3 and 47% (95% CI: 26%-69%, n = 8/17) for SI-4. The median time to SI-3 was 477 days (range, 5-828) and to SI-4 it was 2137 days (range, 9-2137). Gram-positive organisms predominated (93% of SI-2, 94% of SI-3). The majority of SI-2 demonstrated Gram-stain concordance with both the initial (first) SI (58%, 95% CI: 41%-74%) and with the following (third) SI (78%, 95% CI: 55%-91%).

CONCLUSIONS

Children with SI-2 experience high subsequent reinfection rates with a long time to reinfection.

A standardized protocol to reduce cerebrospinal fluid shunt infection: the Hydrocephalus Clinical Research Network Quality Improvement Initiative

OBJECT

Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN).

METHODS

The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation.

RESULTS

Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19-3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43-14.41; p = 0.01) were associated with an increased risk of infection.

CONCLUSIONS

The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will facilitate assessment of new treatments. Identification of factors associated with infection will allow further protocol refinement in the future.

Protective effect of rifampicin and clindamycin impregnated devices against Staphylococcus spp. infection after cerebrospinal fluid diversion procedures

Background

Infection is a major complication of cerebrospinal fluid shunting procedures. The present report assesses the efficacy of such catheters in both shunts and external ventricular drains (EVDs) against infection and particularly against Staphylococcus spp. infection.

Methods

All shunt and EVD procedures performed by means of antibiotic-impregnated catheters (AICs) and non-AICs during the period of study were registered. In cases of shunt procedures, a minimal follow-up of 90 days was considered, as well as de novo insertion and catheter revisions. Single valve revisions were not included. In cases of EVD procedures, those catheters removed before the fifth post-insertion day were not included. A total of 119 cerebrospinal fluid shunting procedures performed with AICs were studied in comparison with 112 procedures performed by means of non-AICs.

Results

Antibiotic-impregnated catheters were associated with a significant decrease in both overall and staphylococcal infection (p = 0.030 and p = 0.045, respectively). The number needed to treat for AICs was 8 to prevent one infection and 14 to prevent one staphylococcal infection. When comparing with shunts, the use of EVDs was associated with a 37-fold increased likelihood of infection.

Conclusions

Antibiotic-impregnated catheters are a safe and helpful tool to reduce CSF shunting device-related infections.

Reinfection following initial cerebrospinal fluid shunt infection

OBJECT

Significant variation exists in the surgical and medical management of CSF shunt infection. The objectives of this study were to determine CSF shunt reinfection rates following initial CSF shunt infection in a large patient cohort and to determine management, patient, hospital, and surgeon factors associated with CSF shunt reinfection.

METHODS

This retrospective cohort study included children who were in the Pediatric Health Information System (PHIS) database, who ranged in age from 0 to 18 years, and who underwent uncomplicated initial CSF shunt placement in addition to treatment for initial CSF shunt infection between January 1, 2001, and December 31, 2008. The outcome was CSF shunt reinfection within 6 months. The main predictor variable of interest was surgical approach to treatment of first infection, which was determined for 483 patients. Covariates included patient, hospital, surgeon, and other management factors.

RESULTS

The PHIS database includes 675 children with initial CSF shunt infection. Surgical approach to treatment of the initial CSF shunt infection was determined for 483 children (71.6%). The surgical approach was primarily shunt removal/new shunt placement (in 286 children [59.2%]), but a substantial number underwent externalization (59 children [12.2%]), of whom a subset went on to have the externalized shunt removed and a new shunt placed (17 children [3.5% overall]). Other approaches included nonsurgical management (64 children [13.3%]) and complete shunt removal without shunt replacement (74 children [15.3%]). The 6-month reinfection rate was 14.8% (100 of 675 patients). The median time from infection to reinfection was 21 days (interquartile range [IQR] 5-58 days). Children with reinfection had less time between shunt placement and initial infection (median 50 vs 79 days, p = 0.06). No differences between those with and without reinfection were seen in patient factors (patient age at either shunt placement or initial infection, sex, race/ethnicity, payer, indication for shunt, number of comorbidities, distal shunt location, and number of shunt revisions at first infection); hospital volume; surgeon volume; or other management factors (for example, duration of intravenous antibiotic use). Nonsurgical management was associated with reinfection, and complete shunt removal was negatively associated with reinfection. However, reinfection rates did not differ between the 2 most common surgical approaches: shunt removal/new shunt placement (44 [15.4%] of 286; 95% CI 11.4%-20.1%) and externalization (total 12 [20.3%] of 59; 95% CI 11.0%-32.8%). Externalization followed by shunt removal/new shunt placement (5 [29.4%] of 17; 95% CI 10.3%-56.0%) and nonsurgical management (15 [23.4%] of 64; 95% CI 13.8%-35.7%) had higher, but nonstatistically significant, reinfection rates. The length of stay was shorter for nonsurgical management.

CONCLUSIONS

Surgical approach to treatment of initial CSF shunt infection was not associated with reinfection in this large cohort of patients.

Effects of antibiotic-impregnated external ventricular drains on bacterial culture results: an in vitro analysis

OBJECT

Treatment of ventriculoperitoneal shunt infections frequently requires placement of an external ventricular drain (EVD). Surveillance specimens obtained from antibiotic-impregnated (AI) EVDs may be less likely to demonstrate bacterial growth, potentially resulting in undertreatment of an infection. The purpose of this study was to assess whether AI EVDs had any significant effect on bacterial culture results compared with nonantibiotic-impregnated (NAI) EVDs.

METHODS

In vitro assays were performed using AI EVDs containing minocycline and rifampin (VentriClear II, Medtronic) and NAI EVD controls (Bioglide, Medtronic). The presence of antibiotics was evaluated via capillary electrophoresis of sterile saline drawn from AI and NAI EVDs after predefined incubation intervals. Antimicrobial activity was assessed by evaluating zones of inhibition created by the catheter aspirates on plates inoculated with a quality control strain of Staphylococcus epidermidis (American Type Culture Collection strain 12228). To determine the effects of cultures drawn through AI compared with NAI EVDs, the quality control strain was then incubated within 4 new AI and 4 new NAI EVDs for predefined intervals before being plated on culture media. Spread and streak plate culture results from each type of catheter were compared at each time interval.

RESULTS

Capillary electrophoresis showed that more minocycline than rifampin was eluted from the AI EVDs. Sterile saline samples incubated within the AI EVDs demonstrated zones of growth inhibition when placed on plates of S. epidermidis at all time intervals tested. No zones of inhibition were noted on NAI EVD control plates. When a standardized inoculum of S. epidermidis was drawn through AI and NAI EVDs, antimicrobial effects were observed after incubation in the AI EVD group only. Colony counting demonstrated that significantly fewer colonies resulted from samples drawn through AI compared with NAI EVDs at the multiple time intervals. Similarly, streak plating yielded a statistically significant number of false-negative results from AI compared with NAI EVDs at 2 time intervals.

CONCLUSIONS

The findings in the current study indicate that the risk of a false-negative culture result may be increased when a CSF sample is drawn through an AI catheter. In the management of a known shunt infection, a false-negative result from an EVD culture specimen may lead to an inappropriately short duration of antibiotic therapy. These data have significant clinical implications, particularly given the widespread use of AI drains and the current high rates of shunt reinfection after EVD use worldwide.