Cerebrospinal Fluid Shunt Infection: Emerging Paradigms in Pathogenesis that Affect Prevention and Treatment

Risk Factors for 30-Day Postoperative Infection in Pediatric Ventricular Shunts for Hydrocephalus

BACKGROUND

Ventricular shunt infections lead to significant morbidity and mortality. This study aimed to identify risk factors for 30-day postoperative infection outcomes of ventricular shunt surgery for pediatric hydrocephalus.

METHODS

This retrospective cohort study used the National Surgical Quality Improvement Program Pediatric database for the years 2016-2021. Patients were included in this study if they were <18 years old and underwent ventricular shunt surgery. The primary outcome was 30-day postoperative shunt infection. A multivariable logistic regression analysis was performed using 14 prognostic variables to determine factors associated with infection risk.

RESULTS

The study included 10,878 patients with a mean (SD) age of 3.1 (4.83) years; 44.2% were girls. The overall 30-day postoperative shunt infection rate was 3.7%. Infection risk increased in patients with nutritional support, longer operating room time, and congenital hydrocephalus. Conversely, infection risk decreased with increasing patient age, delivery of intraoperative intraventricular antibiotics, and first-time shunt placement. Variables that did not significantly affect the risk of 30-day postoperative shunt infection included sex, body mass index, ostomy, tracheostomy, neuromuscular disease, structural pulmonary/airway abnormality, steroid use within 30 days, antibiotic-impregnated shunt use, and endoscopy for catheter placement.

CONCLUSIONS

Various modifiable and nonmodifiable factors are associated with postoperative shunt infections. Recognizing and modifying risk factors can reduce pediatric shunt infections, thereby preventing revisions and improving therapeutic outcomes and quality of life.

Clinical Outcomes and Complication Rates of Ventriculoperitoneal Shunts in Hydrocephalic Infants with Meningomyelocele: A Ten-Year Review at a Single Institution

BACKGROUND/OBJECTIVES

This study aimed to investigate the surgical treatment and management of hydrocephalus in infants with meningomyelocele and compare the single-center experience with the previous studies.

METHODS

This retrospective study included 81 infants (47 females and 34 males) who underwent meningomyelocele closure surgery and subsequent ventriculoperitoneal (VP) shunt surgery for hydrocephalus. Clinical and demographic data were retrospectively collected from hospital records, focusing on variables such as the timing of VP shunt placement relative to MMC closure, postoperative complications, and the need for shunt revisions. Patients were followed for a mean duration of 58.11 months to monitor long-term outcomes and identify factors associated with shunt failures and infections.

RESULTS

The mean follow-up period since birth was 58.11 (33.72) months. Shunt problems affected 30% (25/81) of patients with mechanical causes (8/25) and infections (6/25). A proximal mechanical malfunction/dysfunction was seen in 32% (8/25) of the shunts. Shunt infections occurred in 23% (19/81) of infants, and the mean time for shunt infection onset following the VP shunt procedure was 0 (0-39) median (min-max) months. Overall, 8 (9.9%) infants had short-term shunt infections, whereas 11 (13.6%) had long-term shunt infections. The mean length of the intensive care unit stay was 35.75 (25.28) days. Significant difference was seen in the number of shunt reoperations for short- and long-term infections (p < 0.001). All infants had at least one operation before the infection of their shunt system. Male gender was significantly associated with long-term shunt infections (p = 0.021). The study revealed methicillin-resistant coagulase-negative staphylococcus to be the most common isolated organism from infected shunts at 72.7% (6/11).

CONCLUSIONS

This study demonstrates that hydrocephalic infants with meningomyelocele undergoing VP shunt surgery face notable risks of infection and mechanical complications, with methicillin-resistant coagulase-negative staphylococcus identified as the most common pathogen. The findings emphasize the importance of comprehensive postoperative care and targeted infection management to improve outcomes in this vulnerable population.

A search for bacteria identified from cerebrospinal fluid shunt infections in previous surgical events

Shunt infections are a common complication when treating hydrocephalus by cerebrospinal fluid (CSF) shunt placement. The source of infecting pathogens is not well understood. One hypothesis, which we explored here, is that microorganisms persist chronically in the host long before a symptomatic infection occurs and may be detectable in surgical events preceding infection. A cohort of 13 patients was selected, for which CSF samples were available from an infection episode and from a previous surgery event, which was either an initial shunt placement or a revision. Microbiota were analyzed both directly from CSF and from isolates cultured from CSF on aerobic and anaerobic media. The detection and identification of bacteria was done with high throughput DNA sequencing methods and mass spectrometry. The presence of bacteria was confirmed in 4 infection samples, of which 2 were after initial placement and 2 after revision surgery. Taxonomic identification was consistent with clinical microbiology laboratory results. Bacteria were not detected in any of the CSF samples collected at the time of the previous surgical events. While our findings do not provide direct evidence for long-term persistence of pathogens, they suggest the need for consideration of additional source material, such as biofilm and environmental swabs, and/or the use of more sensitive and specific analytical methods.

Ventriculoperitoneal shunt extrusion in pediatric patients, clinical patterns and therapeutic strategies: A scoping review

Background

Ventriculoperitoneal shunts (VPSs) are frequently employed in neurosurgery to treat hydrocephalus, with a particular focus on pediatric patients. Although VPSs are commonly utilized, they are not exempt from difficulties, such as shunt extrusion. The main aim of this study is to enhance comprehension regarding the occurrence, causes contributing to, and consequences of VPS extrusion in pediatric patients.

Methods

A comprehensive search approach was implemented, including electronic databases, including PubMed, Google Scholar, and Scopus, to locate pertinent articles published between January 1950 and May 2023. The utilization of keywords such as "ventriculoperitoneal shunt" and "extrusion," "ventriculoperitoneal shunt" and "migration," and "ventriculoperitoneal shunt" and "perforation" was employed. Data on patient demographics, underlying diseases, origin of extrusion, presenting symptoms, treatment, and follow-up were gathered. Statistical studies were conducted to identify potential risk factors connected with the occurrence of shunt extrusion.

Results

A study analyzed 80 studies on 120 individuals with extruded VPS catheters. The majority of patients (55.8%) had symptoms such as cerebrospinal fluid leakage and irritation. Hydrocephalus was categorized into congenital (40%), obstructive (36.7%), and communicating (11.7%) groups. Catheter extrusion sites varied, with most from the anal or rectal site. Preoperative meningitis or peritonitis was present in 20% of patients. Treatments ranged from shunt removal to endoscopic third ventriculostomy, resulting in a 90% recovery rate, 1.7% mortality, and 5% follow-up loss.

Conclusion

Extrusion of the distal catheter in VPSs is a critical medical situation that necessitates urgent surgical intervention. The presence of an infection raises the likelihood of complications; hence, it is vital to promptly address the issue through the administration of antibiotics and the replacement of the shunt. Timely intervention enhances results.

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.

The Long-Term Patency of the Internal Jugular Vein and the Common Facial Vein as Entrance Sites for Venous Access in Ventriculoatrial Shunts: A Comparative Analysis from a Single-Center Study

OBJECTIVE

The ventriculoatrial (VA) shunt is a surgical intervention used to manage hydrocephalus, although it is less often utilized compared to the ventriculoperitoneal (VP) shunt or endoscopic third ventriculostomy. Placement of the distal catheter typically involves the utilization of either the common facial vein (CFV) or the internal jugular vein (IJV), 2 frequently employed options for venous access. This study aims to determine whether there is a statistically significant difference between the long-term patency (2 years) of the distal end of the VA shunt of these 2 options.

METHODS

A retrospective cohort analysis was conducted of patients who received VA shunt surgeries with the employment of the CFV or IJV as access veins at Rajavithi Hospital in Thailand between January 2015 and December 2020. The analysis focused on long-term patency and potential complications.

RESULTS

The study comprised a total of 42 participants. Twenty-six (61.9%) individuals underwent ventriculoatrial (VA) shunt surgery via the CFV, while the other 16 (38.1%) underwent the same procedure using the IJV. Neither of the 2 groups required shunt revision due to distal catheter malfunction. Most cases exhibited no significant complications apart from a single instance of shunt system infection.

CONCLUSIONS

In VA shunt surgery, both the CFV and IJV can be used as venous access sites for the right atrium because there is no discernible difference between their complications or long-term patency. Anatomical considerations, patient-specific characteristics, and the surgeon's preference should all be considered when choosing the venous access location for the placement of a VA shunt.

Healthcare-Associated Ventriculitis in Children during COVID-19 Pandemic: Clinical Characteristics and Outcome of a First Infection

During the COVID-19 pandemic, patients in need of neurosurgical care suffered. Elective procedures were postponed, and emergency care visits decreased. Healthcare-associated ventriculitis (HAV) is a serious problem in children, with poor outcomes and frequent relapses. Our objective was to describe the clinical characteristics and the factors associated with a first HAV in children during two years of the pandemic. A retrospective cross-sectional study was performed from January 2021 to December 2022. The inclusion criteria were patients who developed a first HAV after a primary cerebrospinal fluid diversion procedure. The controls included patients without a first infection. Intraoperative and clinical data were extracted from medical records. A total of 199 CSF diversion surgeries were registered. A first infection occurred in 17 patients (8.5%), including 10 with external ventricular drain (EVD) and 6 with ventricular shunts. Gram-positive cocci were identified in 70.6%. Six patients recovered uneventfully, eight had relapse or superinfections, and three eventually died. Twenty patients were included as controls. Factors associated with a first infection were a younger age (median 9 vs. 102 months, p < 0.01), malnutrition (23.5% vs. 0%, p = 0.03), and an EVD placement (58.8% vs. 10%, p = 0.03). None of the intraoperative factors showed statistically significant differences. The rate of HAV was high. Most cases presented in children <1 year and with an EVD.

Lower levels of Th1 and Th2 cytokines in cerebrospinal fluid (CSF) at the time of initial CSF shunt placement in children are associated with subsequent shunt revision surgeries

OBJECTIVE

We compare cytokine profiles at the time of initial CSF shunt placement between children who required no subsequent shunt revision surgeries and children requiring repeated CSF shunt revision surgeries for CSF shunt failure. We also describe the cytokine profiles across surgical episodes for children who undergo multiple subsequent revision surgeries.

METHODS

This pilot study was nested within an ongoing prospective multicenter study collecting CSF samples and clinical data at the time of CSF shunt surgeries since August 2014. We selected cases where CSF was available for children who underwent an initial CSF shunt placement and had no subsequent shunt revision surgeries during >=24 months of follow-up (n = 7); as well as children who underwent an initial CSF shunt placement and then required repeated CSF shunt revision surgeries (n = 3). Levels of 92 human cytokines were measured using the Olink immunoassay and 41 human cytokines were measured using Luminex based bead array on CSF obtained at the time of each child's initial CSF shunt placement and were displayed in heat maps.

RESULTS

Qualitatively similar profiles for the majority of cytokines were observed among the patients in each group in both Olink and Luminex assays. Lower levels of MCP-3, CASP-8, CD5, CXCL9, CXCL11, eotaxin, IFN-γ, IL-13, IP-10, and OSM at the time of initial surgery were noted in the children who went on to require multiple surgeries. Pro- and anti-inflammatory cytokines were selected a priori and shown across subsequent revision surgeries for the 3 patients. Cytokine patterns differed between patients, but within a given patient pro-inflammatory and anti-inflammatory cytokines acted in a parallel fashion, with the exception of IL-4.

CONCLUSIONS

Heat maps of cytokine levels at the time of initial CSF shunt placement for each child undergoing only a single initial CSF shunt placement and for each child undergoing repeat CSF shunt revision surgeries demonstrated qualitatively similar profiles for the majority of cytokines. Lower levels of MCP-3, CASP-8, CD5, CXCL9, CXCL11, eotaxin, IFN-γ, IL-13, IP-10, and OSM at the time of initial surgery were noted in the children who went on to require multiple surgeries. Better stratification by patient age, etiology, and mechanism of failure is needed to develop a deeper understanding of the mechanism of inflammation in the development of hydrocephalus and response to shunting in children.

Cerebrospinal fluid shunt infections in children

Cerebrospinal fluid (CSF) shunts are commonly used for the long-term management of hydrocephalus in children. Shunt infection remains a common complication, occurring in about 5%-15% of CSF shunts. This narrative review summarises key evidence from recent literature on the epidemiology, pathogenesis, clinical presentation, diagnosis, management, outcomes and prevention of CSF shunt infections in children. The majority of shunt infections occur due to contamination at the time of surgery, with coagulase-negative staphylococci and Staphylococcus aureus being the most common infecting organisms. Clinical presentations of shunt infection can be varied and difficult to recognise. CSF cultures are the primary test used for diagnosis. Other CSF and blood parameters may aid in diagnosis but lack sensitivity and specificity. Core aspects of management of shunt infections include systemic antimicrobial therapy and surgical removal of the shunt. However, many specific treatment recommendations are limited by a lack of robust evidence from large studies or controlled trials. Shunt infections may result in long hospital stays, worsening hydrocephalus, neurological sequelae and other complications, as well as death. Therefore, reducing the incidence of infection and optimising management are high priorities. Antibiotic prophylaxis at the time of shunt placement, improved surgical protocols and antibiotic-impregnated shunts are key strategies to prevent shunt infections. Nevertheless, further work is needed to identify additional strategies to prevent complications and improve outcomes.

Characterization of cerebrospinal fluid (CSF) microbiota at the time of initial surgical intervention for children with hydrocephalus

OBJECTIVE

To characterize the microbiota of the cerebrospinal fluid (CSF) from children with hydrocephalus at the time of initial surgical intervention.

STUDY DESIGN

CSF was obtained at initial surgical intervention. One aliquot was stored in skim milk-tryptone-glucose-glycerol (STGG) medium and the second was unprocessed; both were then stored at -70°C. Bacterial growth for CSF samples stored in STGG were subsequently characterized using aerobic and anaerobic culture on blood agar and MALDI-TOF sequencing. All unprocessed CSF samples underwent 16S quantitative polymerase chain reaction (qPCR) sequencing, and a subset underwent standard clinical microbiological culture. CSF with culture growth (either after storage in STGG or standard clinical) were further analyzed using whole-genome amplification sequencing (WGAS).

RESULTS

11/66 (17%) samples stored in STGG and 1/36 (3%) that underwent standard clinical microbiological culture demonstrated bacterial growth. Of the organisms present, 8 were common skin flora and 4 were potential pathogens; only 1 was also qPCR positive. WGAS findings and STGG culture findings were concordant for only 1 sample, identifying Staphylococcus epidermidis. No significant difference in time to second surgical intervention was observed between the STGG culture-positive and negative groups.

CONCLUSION(S)

Using high sensitivity methods, we detected the presence of bacteria in a subset of CSF samples at the time of first surgery. Therefore, the true presence of bacteria in CSF of children with hydrocephalus cannot be ruled out, though our findings may suggest these bacteria are contaminants or false positives of the detection methods. Regardless of origin, the detection of microbiota in the CSF of these children may not have any clinical significance.

A Refined, Controlled 16S rRNA Gene Sequencing Approach Reveals Limited Detection of Cerebrospinal Fluid Microbiota in Children with Bacterial Meningitis

Advances in both laboratory and computational components of high-throughput 16S amplicon sequencing (16S HTS) have markedly increased its sensitivity and specificity. Additionally, these refinements have better delineated the limits of sensitivity, and contributions of contamination to these limits, for 16S HTS that are particularly relevant for samples with low bacterial loads, such as human cerebrospinal fluid (CSF). The objectives of this work were to (i) optimize the performance of 16S HTS in CSF samples with low bacterial loads by defining and addressing potential sources of error, and (ii) perform refined 16S HTS on CSF samples from children diagnosed with bacterial meningitis and compare results with those from microbiological cultures. Several bench and computational approaches were taken to address potential sources of error for low bacterial load samples. We compared DNA yields and sequencing results after applying three different DNA extraction approaches to an artificially constructed mock-bacterial community. We also compared two postsequencing computational contaminant removal strategies, decontam R and full contaminant sequence removal. All three extraction techniques followed by decontam R yielded similar results for the mock community. We then applied these methods to 22 CSF samples from children diagnosed with meningitis, which has low bacterial loads relative to other clinical infection samples. The refined 16S HTS pipelines identified the cultured bacterial genus as the dominant organism for only 3 of these samples. We found that all three DNA extraction techniques followed by decontam R generated similar DNA yields for mock communities at the low bacterial loads representative of CSF samples. However, the limits of detection imposed by reagent contaminants and methodologic bias precluded the accurate detection of bacteria in CSF from children with culture-confirmed meningitis using these approaches, despite rigorous controls and sophisticated computational approaches. Although we did not find current DNA-based diagnostics to be useful for pediatric meningitis samples, the utility of these methods for CSF shunt infection remains undefined. Future advances in sample processing methods to minimize or eliminate contamination will be required to improve the sensitivity and specificity of these methods for pediatric meningitis. IMPORTANCE Advances in both laboratory and computational components of high-throughput 16S amplicon sequencing (16S HTS) have markedly increased its sensitivity and specificity. These refinements have better delineated the limits of sensitivity, and contributions of contamination to these limits, for 16S HTS that are particularly relevant for samples with low bacterial loads such as human cerebrospinal fluid (CSF). The objectives of this work were to (i) optimize the performance of 16S HTS in CSF samples by defining and addressing potential sources of error, and (ii) perform refined 16S HTS on CSF samples from children diagnosed with bacterial meningitis and compare results with those from microbiological cultures. We found that the limits of detection imposed by reagent contaminants and methodologic bias precluded the accurate detection of bacteria in CSF from children with culture-confirmed meningitis using these approaches, despite rigorous controls and sophisticated computational approaches.

A Case of Coccidioidal Meningitis With Biofilm Obstructing VP Shunt Due to Cutibacterium acnes

Herein described is a case of biofilm obstructing ventriculoperitoneal shunt due to Cutibacteirum acnes infection in a patient with coccidioidal meningitis. Cutibacterium acnes infects and obstructs cerebral shunts by the production of biofilm; however, diagnosis is usually missed by routine aerobic cultures. Obtaining anaerobic cultures routinely in patients with foreign body implants leading to central nervous system infections could prevent a missed diagnosis of this pathogen. Penicillin G is the first-line treatment.

Intracranial drainage versus extracranial shunt in the treatment of intracranial arachnoid cysts: a meta-analysis

OBJECTIVE

To review the literature and analyze the efficacy and safety of two surgery procedures, intracranial drainage and extracranial shunt, for intracranial arachnoid cysts.

METHODS

We searched the online Medlars, PubMed, and Cochrane Central electronic databases and collected studies of patients with intracranial arachnoid cysts treated with two surgical methods.

RESULTS

The meta-analysis results shows that there were not statistically significant in clinical symptoms improvement, cyst reduction, the improvement of epilepsy, epidural hematoma, cerebrospinal fluid leak, and recurrence rate (P > 0.05, with RR values are 0.99, 0.94, 1.00, 0.94, 1.21, and 0.75 respectively). There was statistically significant in the occurrence rate of intracranial infection (P = 0.0004, RR = 0.28). The intracranial drainage group was lower than extracranial shunt group.

CONCLUSION

The results indicated that the efficacy and safety of two surgery procedures are similar in the treatment of intracranial arachnoid cysts, but the intracranial drainage was better than extracranial shunt in reducing the risk of intracranial infection.

Pediatric Hydrocephalus and the Primary Care Provider

Hydrocephalus is a pathologic condition that results in the disruption of normal cerebrospinal fluid flow dynamics often characterized by an increase in intracranial pressure resulting in an abnormal dilation of the ventricles. The goal of this article was to provide the necessary background information to understand the pathophysiology related to hydrocephalus, recognize the presenting signs and symptoms of hydrocephalus, identify when to initiate a workup with further studies, and understand the management of pediatric patients with a new and preexisting diagnosis of hydrocephalus.

Efficacy of antimicrobial medicated ventricular catheters: a network meta-analysis with trial sequential analysis

There is paucity of evidence regarding relative performance of antibiotic-medicated (AM), silver-medicated (SM) and non-medicated (NM) ventricular catheters in controlling infection rate. We aim to quantitatively synthesize the current evidence after addition of the three-armed British Antibiotic and Silver Impregnated Catheters for ventriculoperitoneal Shunts (BASICS) trial, understand the need for further evidence using trial sequential analysis (TSA) and incorporate the indirect evidence using network meta-analysis (NMA). Randomized controlled trials (RCTs) comparing AM, SM and NM ventriculoperitoneal shunt (VPS) or external ventricular drain (EVD) were included. Antibiotic-medicated VPS show a significantly lower infection rate as compared to non-medicated VPS (RR 0.44; 95% CI: 0.27-0.73; p = 0.001), however, TSA reveals need for further evidence. SM including both EVD as well as VPS were found to be inferior to AM while no significant difference was found in comparison to the NM catheters. In NMA for VPS, the AM were found to be significantly better than SM (RR 0.41, 95% CI: 0.22-0.75) as well as NM (RR 0.42; 95% CI: 0.25-0.71) with a SUCRA of 99.8% and a mean rank of 1. However, antibiotic medicated shunts did not show a statistically significant association with reoperation rate (RR 0.99; 95% CI:0.81-1.20; p = 0.9) with no further need for evidence as per TSA.

The role of intraventricular antibiotic therapy in the treatment of ventriculo-peritoneal shunt infection in children

BACKGROUND

In this study, the effectiveness of intraventricular (IVT) antibiotic administration was evaluated in the treatment of ventriculo-peritoneal (VP) shunt infection by comparing patients who received only systemic antibiotic treatment with patients who received antibiotics added to systemic therapy by IVT route.

METHODS

From July 2009 to July 2019, 78 shunt infection episodes of 74 pediatric patients with bacterial growth in cerebrospinal fluid (CSF) culture who were treated with the diagnosis of VP shunt infection were retrospectively analyzed. The demographic data, clinical and laboratory parameters, antimicrobial management, and treatment outcomes of patients with VP shunt infections were recorded.

RESULTS

Thirty-eight of 78 shunt episodes received only systemic antibiotic treatment, and 40 had received IV plus IVT treatment. The mean age of the entire patient group was 16.7±21.3 months (range, 1 to 95 months). There was no significant difference between the two treatment groups in terms of mean age. The most common microorganism grown in CSF culture was coagulase-negative Staphylococcus. However, in the group that received IV plus IVT treatment, gram-negative bacteria were predominant (42.1% versus 20%), and this group had carbapenem-resistant and ESBL positive gram-negative bacteria growth. In the duration of CSF sterilization, hospital stay was statistically significantly shorter in the group receiving IV plus IVT treatment (p=0.000, p=0.000, respectively).

CONCLUSION

Our study shows that IVT administration of antibiotics shortens the duration of CSF sterilization, duration of antibiotic use, and the duration of hospital stay. For the treatment of VP shunt infection, the usage of IVT treatment in a particular group of a pediatric age is promising. However, further efforts should be done for supporting the current results by randomized controlled studies.

Severe infections in neurocritical care

PURPOSE OF REVIEW

We have highlighted the recent advances in infection in neurocritical care.

RECENT FINDINGS

Central nervous system (CNS) infections, including meningitis, encephalitis and pyogenic brain infections represent a significant cause of ICU admissions. We underwent an extensive review of the literature over the last several years in order to summarize the most important points in the diagnosis and treatment of severe infections in neurocritical care.

SUMMARY

Acute brain injury triggers an inflammatory response that involves a complex interaction between innate and adaptive immunity, and there are several factors that can be implicated, such as age, genetic predisposition, the degree and mechanism of the injury, systemic and secondary injury and therapeutic interventions. Neuroinflammation is a major contributor to secondary injury. The frequent and challenging presence of fever is a common denominator amongst all neurocritical care patients.

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.

Shunt-Bronchial Fistula with Coughing Up and Swallowing of Cerebrospinal Fluid: Rare Complication of Ventriculopleural Shunt

BACKGROUND

Erosion of the distal catheter into lung parenchyma is an extremely rare complication of ventriculopleural shunt placement.

CASE DESCRIPTION

We report a 51-year-old woman with a history of parasagittal meningioma invading the sagittal sinus who presented with recurrent pneumonia after placement of a ventriculopleural shunt. A nuclear study revealed accumulation of radiotracer material sequentially in the right hemithorax, trachea, mainstem bronchi, stomach, and bowel. The ventriculopleural shunt had eroded into the patient's lung parenchyma, with the effect of cerebrospinal fluid draining into the respiratory system and then being coughed up and swallowed into the gastrointestinal system.

CONCLUSION

Surgeons should be aware of the potential complication of a ventriculopleural shunt eroding through the lung parenchyma to cause a shunt-bronchial fistula with persistent coughing and recurrent pneumonias. Shuntogram nuclear imaging may be useful in the diagnosis of the complication.