Cerebrospinal shunt infection in patients receiving antibiotic-impregnated versus standard shunts

Antibiotic impregnated catheters and intrathecal antibiotics for CSF shunt infection prevention in children undergoing low-risk CSF shunt surgery

BACKGROUND

Cerebrospinal fluid (CSF) shunts allow children with hydrocephalus to survive and avoid brain injury (J Neurosurg 107:345-57, 2007; Childs Nerv Syst 12:192-9, 1996). The Hydrocephalus Clinical Research Network implemented non-randomized quality improvement protocols that were shown to decrease infection rates compared to pre-operative prophylactic intravenous antibiotics alone (standard care): initially with intrathecal (IT) antibiotics between 2007-2009 (J Neurosurg Pediatr 8:22-9, 2011), followed by antibiotic impregnated catheters (AIC) in 2012-2013 (J Neurosurg Pediatr 17:391-6, 2016). No large scale studies have compared infection prevention between the techniques in children. Our objectives were to compare the risk of infection following the use of IT antibiotics, AIC, and standard care during low-risk CSF shunt surgery (i.e., initial CSF shunt placement and revisions) in children.

METHODS

A retrospective observational cohort study at 6 tertiary care children's hospitals was conducted using Pediatric Health Information System + (PHIS +) data augmented with manual chart review. The study population included children ≤ 18 years who underwent initial shunt placement between 01/2007 and 12/2012. Infection and subsequent CSF shunt surgery data were collected through 12/2015. Propensity score adjustment for regression analysis was developed based on site, procedure type, and year; surgeon was treated as a random effect.

RESULTS

A total of 1723 children underwent initial shunt placement between 2007-2012, with 1371 subsequent shunt revisions and 138 shunt infections. Propensity adjusted regression demonstrated no statistically significant difference in odds of shunt infection between IT antibiotics (OR 1.22, 95% CI 0.82-1.81, p = 0.3) and AICs (OR 0.91, 95% CI 0.56-1.49, p = 0.7) compared to standard care.

CONCLUSION

In a large, observational multicenter cohort, IT antibiotics and AICs do not confer a statistically significant risk reduction compared to standard care for pediatric patients undergoing low-risk (i.e., initial or revision) shunt surgeries.

Is It Possible to Eliminate Postoperative Shunt Infections?: Results of a Modified Hydrocephalus Clinical Research Network Protocol

BACKGROUND

 Postoperative shunt infection is a nightmare in neurosurgical practice with additional morbidity and mortality. A lot of protocols have contributed to the reduction of ventriculoperitoneal shunt (VPS) infections but not eradication. The aim of the study was to evaluate the rigid application of a modified Hydrocephalus Clinical Research Network (HCRN) protocol in the prevention of postoperative shunt infection.

METHODS

 We retrospectively evaluated children with congenital hydrocephalus who underwent VPS insertion, and in whom the protocol was applied from June 2019 to January 2020. Follow-up ranged from 11 to 24 months.

RESULTS

 Thirty-seven procedures were performed including 35 primary shunt insertions and two revision surgeries. The median age was 5 months (range, 1-30 months), and 25 patients were males. The most common cause for VPS placement was congenital hydrocephalus without identifiable cause in 28 cases (80%). The endoscope-assisted technique was used in the insertion of the proximal end in six cases (17%). The mean follow-up was 19.4 months (11-24 months). The rate of shunt infection was 0% till the last follow-up.

CONCLUSION

 The preliminary results showed an effective method for the prevention of postoperative shunt infections using the modified protocol. These initial findings need to be validated in a large prospective study before widespread application can be recommended.

Associations of Standard Care, Intrathecal Antibiotics, and Antibiotic-Impregnated Catheters With Cerebrospinal Fluid Shunt Infection Organisms and Resistance

BACKGROUND

Infection prevention techniques used during cerebrospinal fluid (CSF) shunt surgery include: (1) standard perioperative intravenous antibiotics, (2) intrathecal (IT) antibiotics, (3) antibiotic-impregnated catheter (AIC) shunt tubing, or (4) Both IT and AIC. These techniques have not been assessed against one another for their impact on the infecting organisms and patterns of antimicrobial resistance.

METHODS

We performed a retrospective longitudinal observational cohort study of children with initial CSF shunt placement between January 2007 and December 2012 at 6 US hospitals. Data were collected electronically from the Pediatric Health Information Systems+ (PHIS+) database, and augmented with standardized chart review. Only subjects with positive CSF cultures were included in this study.

RESULTS

Of 1,723 children whose initial shunt placement occurred during the study period, 196 (11%) developed infection, with 157 (80%) having positive CSF cultures. Of these 157 subjects, 69 (44%) received standard care, 28 (18%) received AIC, 55 (35%) received IT antibiotics, and 5 (3%) received Both at the preceding surgery. The most common organisms involved in monomicrobial infections were Staphylococcus aureus (38, 24%), coagulase-negative staphylococci (36, 23%), and Cutibacterium acnes (6, 4%). Compared with standard care, the other infection prevention techniques were not significantly associated with changes to infecting organisms; AIC was associated with decreased odds of methicillin resistance among coagulase-negative staphylococci.

CONCLUSIONS

Because no association was found between infection prevention technique and infecting organisms when compared to standard care, other considerations such as tolerability, availability, and cost should inform decisions about infection prevention during CSF shunt placement surgery.

A Proposed Protective Protocol Predicting Reduction of Shunt Infection

OBJECTIVE

To identify the best protective interventions against shunt infection and, hence, to find an appropriate protocol assumed to be associated with reduction of infection rates.

METHODS

A combined prospective-retrospective cohort study was conducted over a period of 5 years in 3 referral hospitals. Twelve interventions against infection practiced by blinded surgeons during ventriculoperitoneal shunt operations were surveyed and their association with the outcome of interest (i.e., shunt infection) was tested. Interventions proved to be associated with the outcome entered a multivariate logistic regression to identify the protective interventions.

RESULTS

Among a total of 392 cases, shunt infection was diagnosed in 11.5% with a median onset of 55 days. Patients' demographics, etiology of hydrocephalus, shunt-related factors, and type of preoperative antibiotics were not associated with shunt infection. Two-thirds of infected shunts revealed Staphylococcus species. Among the tested interventions, double-gloving and device and wound irrigation using vancomycin solution and the use of incision adhesive drapes proved to exhibit a significant protective effect against shunt infection, whereas operative time <40 minutes revealed a marginal protective benefit.

CONCLUSIONS

Shunt infection is a significant complication that occurs early during the first 2 months after surgery. According to the study findings, an appropriate protocol against shunt infection is assumed to be composed of double-gloving, device and wound irrigation using vancomycin solution, and the use of incision adhesive drapes. Reduced operative time had a beneficial effect against shunt infection, although it was of marginal significance in the current study.

Ventriculoperitoneal shunt infection rates using a standard surgical technique, including topical and intraventricular vancomycin: the Children's Hospital Oakland experience

OBJECTIVE

Ventriculoperitoneal (VP) shunt infections are common complications after shunt operations. Despite the use of intravenous antibiotics, the incidence of infections remains high. Though antibiotic-impregnated catheters (AICs) are commonly used, another method of infection prophylaxis is the use of intraventricular (IVT) antibiotics. The authors describe their single-institution experience with a standard shunt protocol utilizing prophylactic IVT and topical vancomycin administration and report the incidence of pediatric shunt infections.

METHODS

Three hundred two patients undergoing VP shunt procedures with IVT and topical vancomycin between 2006 and 2016 were included. Patients were excluded if their age at surgery was greater than 18 years. Shunt operations were performed at a single institution following a standard shunt protocol implementing IVT and topical vancomycin. No AICs were used. Clinical data were retrospectively collected from the electronic health records.

RESULTS

Over the 11-year study period, 593 VP shunt operations were performed with IVT and topical vancomycin, and a total of 19 infections occurred (incidence 3.2% per procedure). The majority of infections (n = 10, 52.6%) were caused by Staphylococcus epidermidis. The median time to shunt infection was 3.7 weeks. On multivariate analysis, the presence of a CSF leak (OR 31.5 [95% CI 8.8-112.6]) and age less than 6 months (OR 3.6 [95% CI 1.2-10.7]) were statistically significantly associated with the development of a shunt infection. A post hoc analysis comparing infection rates after procedures that adhered to the shunt protocol and those that did not administer IVT and topical vancomycin, plus historical controls, revealed a difference in infection rates (3.2% vs 6.9%, p = 0.03).

CONCLUSIONS

The use of a standardized shunt operation technique that includes IVT and topical vancomycin is associated with a total shunt infection incidence of 3.2% per procedure, which compares favorably with the reported rates of shunt infection in the literature. The majority of infections occurred within 2 months of surgery and the most common causative organism was S. epidermidis. Young age (< 6 months) at the time of surgery and the presence of a postoperative CSF leak were statistically significantly associated with postoperative shunt infection on multivariate analysis. The results are hypothesis generating, and the authors propose that IVT and topical administration of vancomycin as part of a standardized shunt operation protocol may be an appropriate option for preventing pediatric shunt infections.

Impact of an educational program on reducing health care-associated meningitis or ventriculitis in the neurosurgical intensive care unit

BACKGROUND

Health care-associated meningitis or ventriculitis (HCAMV) is a serious complication in different neurosurgical procedures and is associated with significant morbidity and mortality. We aimed to investigate whether an educational intervention program could reduce the HCAMV incidence in patients undergoing postsurgery external ventricular drainage and wound management.

METHODS

We enrolled 2,904 patients from the neurosurgery intensive care unit between January 1, 2016 and December 31, 2018. The medical staff undertook an educational program developed by a multidisciplinary team on correct external ventricular drainage insertion and maintenance. The program included a 9-page self-learning module on the HCAMV risk factors and operational improvements. Each participant completed a pre- and posttest on their HCAMV knowledge.

RESULTS

We found that 38 of 693 (5.48%) patients presented with infection in the preintervention 9-month period. In the 27-month postintervention period, the proportion of HCAMV incidence dropped by 52.19% (P < .0001) to 58 of 2,211 (2.62%) patients.

CONCLUSIONS

Educational intervention aimed at the neurosurgery intensive care unit staff could significantly reduce the HCAMV rate, leading to a significant decline in the cost, morbidity, and mortality caused by neurosurgical procedures.

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.

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.

Topical vancomycin reduces the cerebrospinal fluid shunt infection rate: A retrospective cohort study

Object

Despite many efforts at reduction, cerebrospinal fluid (CSF) shunt infections are a major cause of morbidity in shunt surgery, occurring in 5–15% of cases. To attempt to reduce the shunt infection rate at our institution, we added topical vancomycin (intrashunt and perishunt) to our existing shunt infection prevention protocol in 2012.

Methods

We performed a retrospective cohort study comparing all shunted patients in January 2010 to December 2011 without vancomycin (control group, 263 procedures) to all patients who underwent shunt surgery between April 2012 and December 2015 with vancomycin (intervention group, 499 procedures).

Results

The overall shunt infection rate significantly decreased from 6.8% (control group) to 3.0% (intervention group) (p = 0.023, absolute risk reduction 3.8%, relative risk reduction 56%). Multivariate logistic regression analysis confirmed that the addition of topical vancomycin showed that cases treated under a protocol of topical vancomycin were associated with a decreased shunt infection rate (odds ratio [OR] 0.49 95% CI 0.25–0.998; p = 0.049). Age < 1 year was associated with an increased risk of infection (OR) 4.41, 95% CI 2,10–9,26; p = 0.001). Time from surgery to infection was significantly prolonged in the intervention group (p = 0.001).

Conclusion

Adding intraoperative vancomycin to a shunt infection prevention protocol significantly reduces CSF shunt infection rate.

Shunting of the over 80s in normal pressure hydrocephalus

BACKGROUND

Idiopathic normal pressure hydrocephalus is predominantly a disease of the elderly. By its nature, many of those who present to clinic are in advanced old age with multiple comorbidities. Majority of patients treated are younger than 80 years old. We present the clinical outcomes and complication rates of patients over the age of 80 years at the time of operation, during the past 11 years at a single institution.

METHODS

Retrospective analysis of clinical records of all patients over the age of 80 years, who presented to our institution between 2006 and 2016. Results were analysed for co-morbidities, immediate and delayed complications, change in mobility/cognitive function post shunting of hydrocephalus.

RESULTS

39 patients (24 male, 15 female) met criteria. Mean [SD] age at the time of shunt insertion was 84 years (+/- 3.22) (range 80-94). No patients developed immediate CSF infection or sub-dural collection, or extended length of stay due to surgical or anaesthetic complications. There were no peri-operative or anaesthetic complications. 4 patients required a delayed surgical revision to encourage greater CSF drainage. 3 patients went on to develop delayed subdural haematoma, 1 of which was associated with trauma, 2 through overdrainage. 1 patient experienced poor post-operative wound healing and subsequently underwent removal of shunt. Of the 34 patient followed up, 27 patients (79.4%) improved in their mobility. (64.7%) patients/families reported symptomatic improvement in their cognition and memory. 6 (17.7%) patients did not experience an improvement in either mobility or cognitive function.

CONCLUSIONS

Our data supports the assertion that, with proper patient selection, shunting of the over 80s with iNPH is a safe and effective procedure.

Risk factors for surgical site infection following nonshunt pediatric neurosurgery: a review of 9296 procedures from a national database and comparison with a single-center experience

OBJECTIVE Surgical site infection (SSI) following CSF shunt operations has been well studied, yet risk factors for nonshunt pediatric neurosurgery are less well understood. The purpose of this study was to determine SSI rates and risk factors following nonshunt pediatric neurosurgery using a nationwide patient cohort and an institutional data set specifically for better understanding SSI. METHODS The authors reviewed the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (ACS NSQIP-P) database for the years 2012-2014, including all neurosurgical procedures performed on pediatric patients except CSF shunts and hematoma evacuations. SSI included deep (intracranial abscesses, meningitis, osteomyelitis, and ventriculitis) and superficial wound infections. The authors performed univariate analyses of SSI association with procedure, demographic, comorbidity, operative, and hospital variables, with subsequent multivariate logistic regression analysis to determine independent risk factors for SSI within 30 days of the index procedure. A similar analysis was performed using a detailed institutional infection database from Children's of Alabama (COA). RESULTS A total of 9296 nonshunt procedures were identified in NSQIP-P with an overall 30-day SSI rate of 2.7%. The 30-day SSI rate in the COA institutional database was similar (3.3% of 1103 procedures, p = 0.325). Postoperative time to SSI in NSQIP-P and COA was 14.6 ± 6.8 days and 14.8 ± 7.3 days, respectively (mean ± SD). Myelomeningocele (4.3% in NSQIP-P, 6.3% in COA), spine (3.5%, 4.9%), and epilepsy (3.4%, 3.1%) procedure categories had the highest SSI rates by procedure category in both NSQIP-P and COA. Independent SSI risk factors in NSQIP-P included postoperative pneumonia (OR 4.761, 95% CI 1.269-17.857, p = 0.021), immune disease/immunosuppressant use (OR 3.671, 95% CI 1.371-9.827, p = 0.010), cerebral palsy (OR 2.835, 95% CI 1.463-5.494, p = 0.002), emergency operation (OR 1.843, 95% CI 1.011-3.360, p = 0.046), spine procedures (OR 1.673, 95% CI 1.036-2.702, p = 0.035), acquired CNS abnormality (OR 1.620, 95% CI 1.085-2.420, p = 0.018), and female sex (OR 1.475, 95% CI 1.062-2.049, p = 0.021). The only COA factor independently associated with SSI in the COA database included clean-contaminated wound classification (OR 3.887, 95% CI 1.354-11.153, p = 0.012), with public insurance (OR 1.966, 95% CI 0.957-4.041, p = 0.066) and spine procedures (OR 1.982, 95% CI 0.955-4.114, p = 0.066) approaching significance. Both NSQIP-P and COA multivariate model C-statistics were > 0.7. CONCLUSIONS The NSQIP-P SSI rates, but not risk factors, were similar to data from a single center.

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.

Prevention of infection by antibiotic-impregnated shunts after pediatric hydrocephalus treatment: A single center, retrospective study in China

OBJECTIVE

To investigate infection prevention by antibiotic-impregnated shunts (AIS) relative to conventional ones after pediatric hydrocephalus treatment.

METHODS

This single center, retrospective analysis comprised 807 consecutive pediatric cases of hydrocephalus shunting performed by the same neurosurgeon between January 2001 and February 2013. Conventional and AIS catheters were used in 303 and 504 cases, respectively. Study outcomes were infection rates at 6 months (primary), and at 1 month and between 1 and 6 months (secondary). An infant (<1year) subgroup was also analyzed.

RESULTS

The AIS relative to the conventional catheter group had significantly lower infection rates at 6 months (1.98% [10/504] vs. 5.95% [18/303], two-tailed p=0.0046; central nervous system: 60% and 55.56%; abdominal: 20% and 27.77%; wound: 20% and 16.67%, respectively) and 1 month (0.19% [1/504] vs. 2.65% [8/303], p=0.0023, respectively), but statistically similar rates between 1 and 6 months (1.79% [9/504] vs. 3.30% [10/303], p=0.2296, respectively). In the infant subgroup, AIS application was also associated with reduction in shunt infection (1.49% [7/470] vs. 3.76% [10/266], p=0.0489, respectively).

CONCLUSION

AIS as compared to conventional catheter use appears to lower infection risk at 6 months, mainly during the first month, after hydrocephalus therapy in children.

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.

Antibiotic-impregnated catheters reduce ventriculoperitoneal shunt infection rate in high-risk newborns and infants

PURPOSE

The incidence of ventriculoperitoneal (VP) shunt infection accounts for about 5-15%, but it can rise up to 70% in specific high-risk subgroups. Antibiotic-impregnated catheters (AICs) have been designed to reduce shunt infections, but reports on their efficacy are discordant, especially in young children. The aim of this study is to assess, for the first time, the efficacy of AICs in newborns and infants at very high risk for shunt infection.

METHODS

We reviewed the medical records of newborns and infants treated with a VP shunt for newly diagnosed hydrocephalus. Patients were divided in two groups: Group A was composed by children who received AICs, whereas Group B included children implanted with standard silicone catheters (non-AICs). We compared the shunt infection rate in both groups, and analyzed differences in specific high-risk subgroups (preterm newborns, children with posthemorrhagic or postinfective hydrocephalus, and children with a previous external ventricular drainage).

RESULTS

Forty eight children younger than 1 year old were included in our study. Twenty two patients were implanted with an AIC, whereas 26 patients received a standard silicone catheter. The follow-up was at least 1 year (mean 8 ± 3 years). The overall infection rate decreased from 34% in non-AIC group to 9 % in the AIC group. Moreover, AICs showed to have a protective effect against shunt infections in all the specific high-risk subgroups analyzed.

CONCLUSIONS

This study demonstrates for the first time that AICs are effective in reducing VP shunt infection in high-risk pediatric patients younger than 1 year old.

Evidence-based interventions to reduce shunt infections: a systematic review

PURPOSE

Cerebrospinal fluid shunt infection is associated with patient morbidity and high cost. We conducted a systematic review of the current evidence of comprehensive surgical protocols or individual interventions designed to reduce shunt infection incidence.

METHODS

A systematic review using PubMed and SCOPUS identified studies evaluating the effect of a particular intervention on shunt infection risk. Systemic prophylactic antibiotic or antibiotic-impregnated shunt efficacy studies were excluded. A total of 7429 articles were screened and 23 articles were included.

RESULTS

Eight studies evaluated the effect of comprehensive surgical protocols. Shunt infection was reduced in all studies (absolute risk reduction 2.2-12.3 %). Level of evidence was low (level 4 in seven studies) due to the use of historical controls. Compliance ranged from 24.6 to 74.5 %. Surgical scrub with antiseptic foam and omission of a 5 % chlorhexidine gluconate preoperative hair wash were both associated with increased shunt infection. Twelve studies evaluated the effect of a single intervention. Only antibiotic-impregnated suture, a no-shave policy, and double gloving with glove change prior to shunt handling, were associated with a significant reduction in shunt infection. In a hospital with high methicillin-resistant staphylococcus aureus (MRSA) prevalence, a randomized controlled trial found that perioperative vancomycin rather than cefazolin significantly reduced shunt infection rates.

CONCLUSION

Despite wide variation in compliance rates, the implementation of comprehensive surgical protocols reduced shunt infection in all published studies. Antibiotic-impregnated suture, a no-shave policy, double gloving with glove change prior to device manipulation, and 5 % chlorhexidine hair wash were associated with significant reductions in shunt infection.

Antimicrobial-impregnated and -coated shunt catheters for prevention of infections in patients with hydrocephalus: a systematic review and meta-analysis

OBJECT The aim of this study was to evaluate the effectiveness of antimicrobial-impregnated and -coated shunt catheters (antimicrobial catheters) in reducing the risk of infection in patients undergoing CSF shunting or ventricular drainage. METHODS The PubMed and Scopus databases were searched. Catheter implantation was classified as either shunting (mainly ventriculoperitoneal shunting) or ventricular drainage (mainly external [EVD]). Studies evaluating antibioticimpregnated catheters (AICs), silver-coated catheters (SCCs), and hydrogel-coated catheters (HCCs) were included. A random effects model meta-analysis was performed. RESULTS Thirty-six studies (7 randomized and 29 nonrandomized, 16,796 procedures) were included. The majority of data derive from studies on the effectiveness of AICs, followed by studies on the effectiveness of SCCs. Statistical heterogeneity was observed in several analyses. Antimicrobial shunt catheters (AICs, SCCs) were associated with lower risk for CSF catheter-associated infections than conventional catheters (CCs) (RR 0.44, 95% CI 0.35-0.56). Fewer infections developed in the patients treated with antimicrobial catheters regardless of randomization, number of participating centers, funding, shunting or ventricular drainage, definition of infections, de novo implantation, and rate of infections in the study. There was no difference regarding gram-positive bacteria, all staphylococci, coagulase-negative streptococci, and Staphylococcus aureus, when analyzed separately. On the contrary, the risk for methicillin-resistant S. aureus (MRSA, RR 2.64, 95% CI 1.26-5.51), nonstaphylococcal (RR 1.75, 95% CI 1.22-2.52), and gram-negative bacterial (RR 2.13, 95% CI 1.33-3.43) infections increased with antimicrobial shunt catheters. CONCLUSIONS Based on data mainly from nonrandomized studies, AICs and SCCs reduce the risk for infection in patients undergoing CSF shunting. Future studies should evaluate the higher risk for MRSA and gram-negative infections. Additional trials are needed to investigate the comparative effectiveness of the different types of antimicrobial catheters.

Cost-consequence analysis of antibiotic-impregnated shunts and external ventricular drains in hydrocephalus

OBJECT

Despite multiple preventive strategies for reducing infection, up to 15% of patients with shunt catheters and 27% of patients with external ventricular drains (EVDs) may develop an infection. There are few data on the cost-effectiveness of measures to prevent hydrocephalus catheter infection from the hospital perspective. The objective of this study was to perform a cost-consequence analysis to assess the potential clinical and economic value of antibiotic-impregnated catheter (AIC) shunts and EVDs compared with non-AIC shunts and EVDs in the treatment of hydrocephalus from a hospital perspective.

METHODS

The authors used decision analytical techniques to assess the clinical and economic consequences of using antibiotic-impregnated shunts and EVDs from a hospital perspective. Model inputs were derived from the published, peer-reviewed literature. Clinical studies comparing infection rates and the clinical and economic impact of infections associated with the use of AICs and standard catheters (non-AICs) were evaluated. Outcomes assessed included infections, deaths due to infection, surgeries due to infection, and cost associated with shunt- and EVD-related infection. A subanalysis using only AIC shunt and EVD Level I evidence (randomized controlled trial results) was conducted as an alternate to the cumulative analysis of all of the AIC versus non-AIC studies (13 of the 14 shunt studies and 4 of the 6 EVD studies identified were observational). Sensitivity analyses were conducted to determine how changes in the values of uncertain parameters affected the results of the model.

RESULTS

In 100 patients requiring shunts, AICs may be associated with 0.5 fewer deaths, 71 fewer hospital days, 11 fewer surgeries, and $128,228 of net savings in hospital costs due to decreased infection. Results of the subanalysis showed that AICs may be associated with 1.9 fewer deaths, 1611 fewer hospital days, 25 fewer surgeries, and $346,616 of net savings in hospital costs due to decreased infection. The rate of decrease in infection with AIC shunts was shown to have the greatest impact on the cost savings realized with use of AIC shunts.

In 100 patients requiring EVDs, AICs may be associated with 2.7 fewer deaths and 82 fewer hospital days due to infection. The relative risk of more severe neurological impairment was estimated to be 5.33 times greater with EVD infection. Decreases in infection with AIC EVDs resulted in an estimated $264,069 of net savings per 100 patients treated with AICs. Results of the subanalysis showed that AIC EVDs may be associated with 1.0 fewer deaths, 31 infection-related hospital days averted, and $74,631 saved per 100 patients treated with AIC EVDs. As was seen with AIC shunts, the rate of decrease in infection with AIC EVDs was shown to have the greatest impact on the cost savings realized with use of AIC EVDs.

CONCLUSIONS

The current value analysis demonstrates that evidence supports the use of AICs as effective and potentially cost-saving treatment.

Ventriculoperitoneal Shunt in a Patient with Ruptured Blister Aneurysm Treated with Pipeline Embolization Device

Cerebral spinal fluid (CSF) diversion is frequently required in patients with aneurysmal subarachnoid hemorrhage who develop subsequent hydrocephalus. Procedures such as external ventricular drain (EVD) and ventriculoperitoneal shunt (VPS) usually carry a very low rate of complications. However, as flow diverting stents such as Pipeline Embolization Device (PED) become more widely available, flow diverters are being used in treatment of some ruptured complex aneurysms. EVD and VPS placement in the setting of dual antiplatelet therapy (DAT) in these patients are associated with a significant risk of intracranial hemorrhage. We describe a management strategy and surgical technique that can minimize hemorrhagic complications associated with VPS in patients on DAT after treatment with flow diverting stents.

Comparative effectiveness of antibiotic-impregnated shunt catheters in the treatment of adult and pediatric hydrocephalus: analysis of 12,589 consecutive cases from 287 US hospital systems

OBJECT

The real-world effectiveness of antibiotic-impregnated shunt catheters to reduce the incidence of shunt infections is still debated. The literature to date consists mostly of small, single-institution studies. The aim of this study was to assess the incidence of infection for antibiotic-impregnated catheters (AICs) versus standard shunt catheters in a large nationwide administrative database.

METHODS

The authors retrospectively reviewed hospital discharge and billing records from the Premier Perspective Database from April 2003 to July 2009 to identify all adult and pediatric patients undergoing de novo ventricular shunt placement. The primary end point was the incidence of shunt infection within 1 year of implantation. Multivariate logistical regression was performed to determine factors associated with increased incidence of infection.

RESULTS

A total of 10,819 adult (AIC, 963; standard catheter, 9856) and 1770 pediatric (AIC, 229; standard catheter, 1541) patients underwent ventricular shunt placement in 287 US hospitals. Overall, the incidence of infection was 3.5% in adults (n=380) and 6.6% in pediatric patients (n=116). AICs were associated with significant reduction in infection for both adult (2.2% vs 3.6%, p=0.02) and pediatric (2.6% vs 7.1%, p<0.01) patients. AIC use was associated with reduced infection regardless of hospital size, annual shunt volume, hospital location, or patient risk factors and remained associated with a reduced infection in multivariate analysis for both adult (p=0.02) and pediatric (p=0.02) patients.

CONCLUSIONS

The use of antibiotic-impregnated shunt catheters was associated with a reduction in shunt infections for both adult and pediatric patients. This provides further support that AICs may represent a reliable means of reducing shunt infections for both adult and pediatric patients.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 7: Antibiotic-impregnated shunt systems versus conventional shunts in children: a systematic review and meta-analysis

OBJECT

The objective of this systematic review and meta-analysis was to answer the following question: Are antibiotic-impregnated shunts (AISs) superior to standard shunts (SSs) at reducing the risk of shunt infection in pediatric patients with hydrocephalus?

METHODS

Both the US National Library of Medicine PubMed/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to AIS use in children. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected. An evidentiary table was assembled summarizing the studies and the quality of their evidence (Classes I-III). A meta-analysis was conducted using a random-effects model to calculate a cumulative estimate of treatment effect using risk ratio (RR). Heterogeneity was assessed using the chi-square and I(2) statistics. Based on the quality of the literature and the result of the meta-analysis, a recommendation was rendered (Level I, II, or III).

RESULTS

Six studies, all Class III, met our inclusion criteria. All but one study focused on a retrospective cohort and all but one were conducted at a single institution. Four of the studies failed to demonstrate a lowered infection rate with the use of an AIS. However, when the data from individual studies were pooled together, the infection rate in the AIS group was 5.5% compared with 8.6% in the SS group. Using a random-effects model, the cumulative RR was 0.51 (95% CI 0.29-0.89, p < 0.001), indicating that a shunt infection was 1.96 times more likely in patients who received an SS.

CONCLUSIONS

We recommend AIS tubing because of the associated lower risk of shunt infection compared to the use of conventional silicone hardware (quality of evidence: Class III; strength of recommendation: Level III).

RECOMMENDATION

Antibiotic-impregnated shunt (AIS) tubing may be associated with a lower risk of shunt infection compared with conventional silicone hardware and thus is an option for children who require placement of a shunt.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

Cost savings associated with antibiotic-impregnated shunt catheters in the treatment of adult and pediatric hydrocephalus

BACKGROUND

Cerebrospinal fluid (CSF) shunt infection is a major cause of morbidity and mortality in the treatment of hydrocephalus and is associated with significant medical cost. Several studies have demonstrated the efficacy of antibiotic-impregnated (AI) shunt catheters in reducing CSF shunt infection; however, providers remain reluctant to adopt AI catheters into practice because of the increased upfront cost. The objective of this study was to determine if the use of AI catheters provided cost savings in a large nationwide database.

METHODS

Hospital discharge and billing records from the Premier Perspective Database from 2003-2009 were retrospectively reviewed to identify all adult and pediatric patients undergoing de novo ventricular shunt placement. The incidence of shunt infection within 1 year of implantation was determined. Shunt infection-related cost was defined as all inpatient billing costs incurred during hospitalization for treatment of shunt infection.

RESULTS

In 287 U.S. hospitals, 10,819 adult (AI catheters, 963; standard catheters, 9856) and 1770 pediatric (AI catheters, 229; standard catheters, 1541) patients underwent ventricular shunt placement. AI catheters were associated with significant reduction in infection for both adult (2.2% vs. 3.6%, P = 0.02) and pediatric (2.6% vs. 7.1%, P < 0.01) patients. Total infection-related costs were $17,371,320 ($45,714 ± $49,745 per shunt infection) for adult patients and $6,508,064 ($56,104 ± $65,746 per shunt infection) for pediatric patients. Infection-related cost per 100 de novo shunts placed was $120,534 for AI catheters and $162,659 for standard catheters in adult patients and $165,087 for AI catheters and $395,477 for standard catheters in pediatric patients.

CONCLUSIONS

In analysis of this large, nationwide database, AI catheters were found to be associated with a significant reduction in infection incidence, resulting in tremendous cost savings. AI catheters were associated with a cost savings of $42,125 and $230,390 per 100 de novo shunts placed in adult and pediatric patients, respectively.

Effectiveness of the Bactiseal Universal Shunt for reducing shunt infection in a sub-Saharan African context: a retrospective cohort study in 160 Ugandan children

OBJECT

Antibiotic-impregnated shunts have yet to find widespread use in the developing world, largely due to cost. Given potential differences in the microbial spectrum, their effectiveness in preventing shunt infection for populations in low-income countries may differ and has not been demonstrated. This study is the first to compare the efficacy of a Bactiseal shunt system with a non-antibiotic-impregnated system in a developing country.

METHODS

The Bactiseal Universal Shunt (BUS) was placed in 80 consecutive Ugandan children who required a shunt. In this retrospective cohort study, the outcome for that group was compared with the outcome for the immediately preceding 80 consecutive children in whom a Chhabra shunt had been placed. The primary end points were shunt failure, shunt infection, and death. Shunt survival was analyzed using the Kaplan-Meier method. Significance of differences between groups was tested using the log-rank test, chi-square analysis, Fisher's exact test, and t-test.

RESULTS

There was no difference between groups in regard to age, sex, or etiology of hydrocephalus. Mean follow-up for cases of nonfailure was 7.6 months (median 7.8 months, interquartile range 6.5-9.5 months). There was no significant difference between groups for any end point. The BUS group had fewer infections (4 vs 11), but the difference was not significant (p = 0.086, log-rank test). Gram-positive cocci were the most common culturable pathogens in the Chhabra group, while the only positive culture in the BUS group was a gram-negative rod.

CONCLUSIONS

These results provide equipoise for a randomized controlled trial in the same population and this has been initiated. It is possible that the observed trends may become significant in a larger study. The more complex task will involve determining not only the efficacy, but also the cost-effectiveness of using antibiotic-impregnated shunt components in limited-resource settings.

Early and late complications of germinal matrix-intraventricular haemorrhage in the preterm infant: what is new?

Germinal matrix-intraventricular haemorrhage (GMH-IVH) remains a serious problem in the very and extremely preterm infant. This article reviews current methods of diagnosis, treatment and neurodevelopmental outcome in preterm infants with low-grade and severe GMH-IVH. We conclude that there is still no consensus on timing of intervention and treatment of infants with GMH-IVH, whether or not complicated by post-haemorrhagic ventricular dilatation. The discrepancies between the studies underline the need for international collaboration to define the optimal strategy for these infants.

Effect of introduction of antibiotic-impregnated shunt catheters on cerebrospinal fluid shunt infection in children: a large single-center retrospective study

OBJECT

Infection after both primary and revision shunt surgeries remains a major problem in pediatric neurosurgical practice. Antibiotic-impregnated shunt (AIS) tubing has been proposed to reduce infection rates. The authors report their experience with AIS catheters in their large pediatric neurosurgery department.

METHODS

The authors conducted a retrospective case review of consecutive shunt operations performed before (1993-2003) and after (2005-2009) introduction of AIS tubing, with analysis of shunt infection rates and causative organisms identified.

RESULTS

The historical control group consisted of 1592 consecutive shunt operations (657 primary insertions), and the AIS study group consisted of 500 consecutive shunt operations (184 primary insertions). Patients ranged in age from 0-17 years. In the historical group, 135 infections were identified (8.4%). In the AIS study group, 25 infections were identified (5%), representing a significant reduction (p < 0.005). The latency to diagnosis of infection was 23 days in the historical group and 139 days in the AIS study group. The infection rates in infants 0-6 months of age were 12.2% (historical group) and 6.7% (AIS group, p < 0.005), and in infants 7-12 months of age the rates were 7.9% (historical group) and 2.7% (AIS group, p < 0.005). In the historical control group, the frequency rank order of causative organisms was coagulase-negative staphylococcus (51.9%), Staphylococcus aureus (31.6%), streptococcus or enterococcus spp. (8.8%), gram-negative organisms (4.4%), and Propionibacterium acnes (2.2%). Organisms responsible for infections in AIS were S. aureus (40%), followed by streptococcus or enterococcus spp. (20%), P. acnes and coagulase-negative staphylococcus (both 16%), and gram-negative organisms (4%). No unusually antibiotic-resistant bacteria were identified in either group. The authors further subdivided the AIS group into those undergoing primary AIS insertion (Subgroup 1), those undergoing revision of non-AIS systems using AIS components (Subgroup 2), and those undergoing revision of AIS systems using AIS components (Subgroup 3). Infection rates were 1.6% in Subgroup 1, 2.5% in Subgroup 2, and 11.7% in Subgroup 3. Staphylococcus aureus was the most common organism identified in infections of the Subgroups 2 and 3.

CONCLUSIONS

Use of AIS tubing significantly improves shunt infection rates in both general pediatric and infant populations with no evidence of increased antibiotic resistance, which is in agreement with previous studies. However, the increased infection rate in revision surgery in children with AIS catheters in situ raises questions about their long-term application.

Propionibacterium acnes: an underestimated pathogen in implant-associated infections

The role of Propionibacterium acnes in acne and in a wide range of inflammatory diseases is well established. However, P. acnes is also responsible for infections involving implants. Prolonged aerobic and anaerobic agar cultures for 14 days and broth cultures increase the detection rate. In this paper, we review the pathogenic role of P. acnes in implant-associated infections such as prosthetic joints, cardiac devices, breast implants, intraocular lenses, neurosurgical devices, and spine implants. The management of severe infections caused by P. acnes involves a combination of antimicrobial and surgical treatment (often removal of the device). Intravenous penicillin G and ceftriaxone are the first choice for serious infections, with vancomycin and daptomycin as alternatives, and amoxicillin, rifampicin, clindamycin, tetracycline, and levofloxacin for oral treatment. Sonication of explanted prosthetic material improves the diagnosis of implant-associated infections. Molecular methods may further increase the sensitivity of P. acnes detection. Coating of implants with antimicrobial substances could avoid or limit colonization of the surface and thereby reduce the risk of biofilm formation during severe infections. Our understanding of the role of P. acnes in human diseases will likely continue to increase as new associations and pathogenic mechanisms are discovered.

A review of the clinical implications of anti-infective biomaterials and infection-resistant surfaces

Infection is currently regarded as the most severe and devastating complication associated to the use of biomaterials. The important social, clinical and economic impacts of implant-related infections are promoting the efforts to obviate these severe diseases. In this context, the development of anti-infective biomaterials and of infection-resistant surfaces is being regarded as the main strategy to prevent the establishment of implant colonisation and biofilm formation by bacteria. In this review, the attention is focused on the biomaterial-associated infections, from which the need for anti-infective biomaterials originates. Biomaterial-associated infections differ markedly for epidemiology, aetiology and severity, depending mainly on the anatomic site, on the time of biomaterial application, and on the depth of the tissues harbouring the prosthesis. Here, the diversity and complexity of the different scenarios where medical devices are currently utilised are explored, providing an overview of the emblematic applicative fields and of the requirements for anti-infective biomaterials.

Patterns in neurosurgical adverse events: cerebrospinal fluid shunt surgery

Object

As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in CSF shunt surgery concerning the frequency of adverse events in practice, their patterns, and the state of knowledge regarding methods for their reduction. This review may also inform future and ongoing efforts for the advancement of neurosurgical quality.

Methods

The authors performed a PubMed search using search terms “cerebral shunt,” “cerebrospinal fluid shunt,” “CSF shunt,” “ventriculoperitoneal shunt,” “cerebral shunt AND complications,” “cerebrospinal fluid shunt AND complications,” “CSF shunt AND complications,” and “ventriculoperitoneal shunt AND complications.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the adverse events reported.

Results

In this review of the neurosurgery literature, the reported rate of mechanical malfunction ranged from 8% to 64%. The use of programmable valves has increased but remains of unproven benefit even in randomized trials. Infection was the second most common complication, with the rate ranging from 3% to 12% of shunt operations. A meta-analysis that included 17 randomized controlled trials of perioperative antibiotic prophylaxis demonstrated a decrease in shunt infection by half (OR 0.51, 95% CI 0.36–0.73). Similarly, use of detailed protocols including perioperative antibiotics, skin preparation, and limitation of OR personnel and operative time, among other steps, were shown in uncontrolled studies to decrease shunt infection by more than half.

Other adverse events included intraabdominal complications, with a reported incidence of 1% to 24%, intracerebral hemorrhage, reported to occur in 4% of cases, and perioperative epilepsy, with a reported association with shunt procedures ranging from 20% to 32%. Potential management strategies are reported but are largely without formal evaluation.

Conclusions

Surgery for CSF shunt placement or revision is associated with a high complication risk due primarily to mechanical issues and infection. Concerted efforts aimed at large-scale monitoring of neurosurgical complications and consistent quality improvement within these highlighted realms may significantly improve patient outcomes.

EDTA inhibits biofilm formation, extracellular vesicular secretion, and shedding of the capsular polysaccharide glucuronoxylomannan by Cryptococcus neoformans

The fungal pathogen Cryptococcus neoformans can grow as a biofilm on a range of synthetic and prosthetic materials. Cryptococcal biofilm formation can complicate the placement of shunts used to relieve increased intracranial pressure in cryptococcal meningitis and can serve as a nidus for chronic infection. Biofilms are generally advantageous to pathogens in vivo, as they can confer resistance to antimicrobial compounds, including fluconazole and voriconazole in the case of C. neoformans. EDTA can inhibit biofilm formation by several microbes and enhances the susceptibility of biofilms to antifungal drugs. In this study, we evaluated the effect of sublethal concentrations of EDTA on the growth of cryptococcal biofilms. EDTA inhibited biofilm growth by C. neoformans, and the inhibition could be reversed by the addition of magnesium or calcium, implying that the inhibitory effect was by divalent cation starvation. EDTA also reduced the amount of the capsular polysaccharide glucuronoxylomannan shed into the biofilm matrix and decreased vesicular secretion from the cell, thus providing a potential mechanism for the inhibitory effect of this cation-chelating compound. Our data imply that the growth of C. neoformans biofilms requires the presence of divalent metals in the growth medium and suggest that cations are required for the export of materials needed for biofilm formation, possibly including extracellular vesicles.