Cerebrospinal fluid shunt infections in children. A study on the relationship between the etiology of hydrocephalus, age at the time of shunt placement, and infection rate

Surgical treatment outcome of children with neural-tube defect: A prospective cohort study in a high volume center in Addis Ababa, Ethiopia

Introduction

Prevalence of neural tube defects (NTD) is high thus many children are born with a neural tube defect in Addis Ababa, and surgical closure is a commonly performed procedure at the pediatric neurosurgical specialty center.

Research question

The primary aim is to study the outcomes in children undergoing surgical closure of NTDs and to identify risk factors for readmission, complications and mortality.

Material and methods

Single-center prospective study of all surgically treated NTDs from April 2019 to May 2020.

Results

A total of 228 children, mean age 11 days (median 4) underwent surgery during the study period. There were no in-hospital deaths. Perioperatively 11 (4.8%) children developed wound complications, none of them needed surgery and there was no perioperative mortality. The one-year follow-up rate was 62.7% (143/228) and neurological status remained stable since discharge in all. The readmission and reoperation rates were 38 % and 8 % and risk factors for readmission were hydrocephalus (80%) and open defects (88%). Hydrocephalus (P = 0.05) and younger age (P = 0.02) were identified as risk factors for mortality. The wound-related complication rate was 55% at and was associated with large defects (P = 0.04) and delayed closure due to late hospital presentation (P = 0.01).

Discussion and conclusion

The study reveals good perioperative surgical outcome and further need for systematic improvement in treatment and follow-up of NTD patients especially with hydrocephalus. We identified risk factors for wound-related complications, readmission and mortality.

Predictors and Outcome of Ventriculoperitoneal Shunt Infection: A Retrospective Single-Center Study

Background:Shunt infection critically affects approximately 8-10% of all inserted shunts, leading to significant morbidity and mortality. This study aimed to assess the clinical and laboratory factors associated with shunt infection and outcomes in patients treated for hydrocephalus.

Methods: A retrospective study was performed on patients who underwent ventriculoperitoneal shunt (VPS) surgery for hydrocephalus between January 2015 and June 2018. The primary outcome was the development of shunt infection following VPS surgery. Records were reviewed, and variables were analyzed, including patients' demographics, perioperative laboratory and shunt data, and outcomes. The patients had five years of follow-up from surgery, including a minimum of two years from the onset of VPS infection.

Results:A total of 132 shunts were inserted in 103 patients with a mean age of 2 years (range; 2 days to 73 years), and 53.4% were males. Twenty-two patients were suspected of having VPS infection (16.7% per procedure); only six (4.5%) had positive cerebrospinal fluid (CSF) detected organisms. Patients with preoperative hemoglobin, white blood cells, and serum glucose within normal values had a lower shunt infection rate. The pediatric population had an elevated risk of VPS infection, particularly those who underwent surgery at a younger age than 7.5 months, weighed less than 10 Kg, and were associated with myelomeningocele. in addition, a shorter surgery time of less than 82 min, single surgeon, and operating room of fewer than four attendees are associated with lower risk of VPS infection.

Conclusion:We emphasize that early identification and modifications of the risk factors can minimize the probability of developing VPS infection and improve patients outcome.

Evaluation of an in vivo model for ventricular shunt infection: a pilot study using a novel antimicrobial-loaded polymer

OBJECTIVE

Ventricular shunt infection remains an issue leading to high patient morbidity and cost, warranting further investigation. The authors sought to create an animal model of shunt infection that could be used to evaluate possible catheter modifications and innovations.

METHODS

Three dogs underwent bilateral ventricular catheter implantation and inoculation with methicillin-sensitive Staphylococcus aureus (S. aureus). In 2 experimental animals, the catheters were modified with a polymer containing chemical "pockets" loaded with vancomycin. In 1 control animal, the catheters were polymer coated but without antibiotics. Animals were monitored for 9 to 11 days, after which the shunts were explanted. MRI was performed after shunt implantation and prior to catheter harvest. The catheters were sonicated prior to microbiological culture and also evaluated by electron microscopy. The animals' brains were evaluated for histopathology.

RESULTS

All animals underwent successful catheter implantation. The animals developed superficial wound infections, but no neurological deficits. Imaging demonstrated ventriculitis and cerebral edema. Harvested catheters from the control animal demonstrated > 104 colony-forming units (CFUs) of S. aureus. In the first experimental animal, one shunt demonstrated > 104 CFUs of S. aureus, but the other demonstrated no growth. In the second experimental animal, one catheter demonstrated no growth, and the other grew trace S. aureus. Brain histopathology revealed acute inflammation and ventriculitis in all animals, which was more severe in the control.

CONCLUSIONS

The authors evaluated an animal model of ventricular shunting and reliably induced features of shunt infection that could be microbiologically quantified. With this model, investigation of pathophysiological and imaging correlates of infection and potentially beneficial shunt catheter modifications is possible.

Intracranial infection in patients with myelomeningocele: profile and risk factors

PURPOSE

To describe the profile and determine the risk factors for the development of intracranial infections (ICI) in paediatric patients with myelomeningocele (MMC).

METHODS

Retrospective analysis of data from the records of patients with MMC admitted into our hospital between January 2006 and December 2015.

RESULTS

We managed a total of 688 paediatric non-trauma neurosurgical patients in our facility during the study period. 29.4% of these patients had MMC. We found the records for 49% of the patients. The male: female ratio was 1.3:1. Most of the MMCs were located in the lumbosacral region (71.7%). The lesion was ruptured in 42.4%, unruptured in 53.5%, and indeterminate in 4.0% of the patients. 48.5% of the MMCs were infected at presentation. Surgical repair of the spinal dysraphism was performed in 74.7% of the patients. Postoperative complications observed in our series include wound dehiscence, cerebrospinal fluid leak, and pseudomeningocele which occurred in 13.5%, 12.2%, and 2.7% of the operated cases of MMC respectively. 28.3% of the patients with MMC developed ICI during the course of hospitalization. 71.4% of patients with MMC-associated ICI had septic neural placode at the initial clinical evaluation. 70% of the patients who had wound dehiscence post-operatively developed ICI. Loculations and abscesses occurred only in patients who had surgical repair. A multivariate logistic regression analysis revealed that septic neural placode, hydrocephalus, a supra-lumbar location of the MMCs and surgical intervention were predictive of ICI (p < 0.05).

CONCLUSION

Infection of the neural placode, hydrocephalus, locations of the lesions above the lumbar region, and surgical repair were the statistically significant risk factors for ICI in our study population. The trending but statistically insignificant risk factors for ICI in our series may require further assessment with a larger sample size.

Infection risk for Bactiseal Universal Shunts versus Chhabra shunts in Ugandan infants: a randomized controlled trial

OBJECTIVE Clinical and economic repercussions of ventricular shunt infections are magnified in low-resource countries. The efficacy of antibiotic-impregnated shunts in this setting is unclear. A previous retrospective cohort study comparing the Bactiseal Universal Shunt (BUS) and the Chhabra shunt provided clinical equipoise; thus, the authors conducted this larger randomized controlled trial in Ugandan children requiring shunt placement for hydrocephalus to determine whether there was, in fact, any advantage of one shunt over the other. METHODS Between April 2013 and September 2016, the authors randomly assigned children younger than 16 years of age without evidence of ventriculitis to either BUS or Chhabra shunt implantation in this single-blind randomized controlled trial. The primary outcome was shunt infection, and secondary outcomes included reoperation and death. The minimum follow-up was 6 months. Time to outcome was assessed using the Kaplan-Meier method. The significance of differences was tested using Wilcoxon rank-sum, chi-square, Fisher’s exact, and t-tests. RESULTS Of the 248 patients randomized, the BUS was implanted in 124 and the Chhabra shunt in 124. There were no differences between the groups in terms of age, sex, or hydrocephalus etiology. Within 6 months of follow-up, there were 14 infections (5.6%): 6 BUS (4.8%) and 8 Chhabra (6.5%; p = 0.58). There were 14 deaths (5.6%; 5 BUS [4.0%] vs 9 Chhabra [7.3%], p = 0.27) and 30 reoperations (12.1%; 15 BUS vs 15 Chhabra, p = 1.00). There were no significant differences in the time to primary or secondary outcomes at 6 months’ follow-up (p = 0.29 and 0.17, respectively, Wilcoxon rank-sum test). CONCLUSIONS Among Ugandan infants, BUS implantation did not result in a lower incidence of shunt infection or other complications. Any recommendation for a more costly standard of care in low-resource countries must have contextually relevant, evidence-based support. Clinical trial registration no.: PACTR201804003240177 (http://www.pactr.org/)

Surgical treatment of post-inflammatory hydrocephalus. Analysis of 101 cases

OBJECTIVE

The aim of this paper was to evaluate the outcomes of surgical treatment for post-inflammatory hydrocephalus in pediatric patients. The patient's age, surgical technique and type of implants, revision rate (depending on the cause for revision and shunt type), and final outcome measured with Neurologic Outcome Scale for Infants and Children (NOSIC) scale were evaluated.

METHODS

We performed a retrospective analysis of 101 patients with post-inflammatory hydrocephalus, treated in Polish Mother's Memorial Hospital Research Institute since 2005. Children with comorbidities (e.g., tumors or hemorrhages) were excluded from the study. The assessment included patient age, surgical technique (ventriculoperitoneal shunt (VPS) or neuroendoscopy) and type of implant, revision rate (considering its cause), and final outcome measured in Neurologic Outcome Scale for Infants and Children (NOSIC) scale.

RESULTS

VPS implantation was the most common surgical technique. It was performed in 66.33% (n = 67) of cases. Neuroendoscopic procedure was used in 33.66% of cases (n = 34). Revision rate of VPS was 52.23% (n = 35). Endoscopic third ventricle ventriculostomy (ETV) was efficient only in 5 cases (14.7%), whereas in 29 cases (85.3%), it was followed by VPS implantation. Revision rate in VPS implantation after ETV reached 55.17% (n = 16). In all age groups, VPS implantation was the most frequently used procedure. Revisions of the shunt systems occurred most frequently in the 1-3 (n = 21 41.18%) and < 1 (n = 12, 23.53%) age ranges. The type of valve that most often underwent dysfunction was flow-regulated type (n = 23, 62.16%). The type of valve that was the least frequently revised was differential pressure type (n = 11, 17.18%). In all age groups, mechanical dysfunction was the most frequent cause of shunt disability. Average NOSIC score ranged from 39 to 98 (average 80.58, standard deviation ± 13.34). NOSIC result relative to individual operational techniques was as follows: ETV + VPS-80.17 (n = 29, standard deviation ± 11.44), VPS-80.44 (n = 67, standard deviation ± 14.30), and ETV-80.80 (n = 5, standard deviation ± 11.62). There was no difference between the outcome of the NOSIC and the type of implanted valve or its dysfunction.

CONCLUSIONS

In our analysis, post-inflammatory hydrocephalus accounts for 11.7% of all hydrocephalus types. Of post-inflammatory hydrocephalus, multiloculated type accounts for 14.9%. The most common type of surgery in these patients is implantation of the ventriculoperitoneal system. The most frequent revisions of the VPS system occur in the group of the younger children (< 3). The most common type of a dysfunction shunt is the differential pressure valve, and the rarest type the flow-regulated type. In the case of mechanical dysfunction, occlusion of the intraventricular catheter is the most common reason. ETV does not affect the frequency of VPS revisions. The average NOSIC score in children treated with hydrocephalus is below normal, and the best results are observed in the youngest children.

Effect of introduction of a standardised peri-operative protocol on CSF shunt infection rate: a single-centre cohort study of 809 procedures

PURPOSE

Shunt infection is a major problem in paediatric neurosurgery. Our institution introduced a mandatory shunt protocol with the aim of reducing infection rate.

METHODS

A retrospective cohort study including consecutive patients undergoing permanent shunt operations (primary insertion and revision) across two study periods: 3 years immediately prior (2009-2012) and 3 years immediately after (2012-2015) protocol introduction. Absolute and relative risk reductions (ARR/RRR) and Chi-square statistical analysis was used alongside logistic regression, where any single factor with p ≤ 0.20 included in the multivariate model, producing an odds ratio (OR).

RESULTS

Eight hundred nine operations in 504 children were identified (442 pre-protocol, 367 post). Overall infection rate decreased from 5.43% (24/442) pre-protocol to 3.27% (12/367) post-protocol (ARR = 2.16%, RRR = 39.8%, NNT = 46.3, p = 0.138), which did not reach statistical significance. For primary shunt insertions, infection rate reduced from 3.63 to 2.55% (ARR = 1.08%, RRR = 29.8%, NNT = 92.6, p = 0.565), whilst for revisions, it reduced from 6.83 to 3.81% (ARR = 3.02%, RRR 44.2%, NNT = 33.1, p = 0.156). Multivariate logistic regression showed that surgeon experience was a statistically significant predictor of infection, whilst responsible pathogens and latency were similar across the pre- and post-protocol groups.

CONCLUSION

The protocol reduced overall infection rate in primary and revision shunt operations and we recommend paediatric units consider introducing a similar protocol for these procedures.

Relationship between the location of the ventricular catheter tip and the ventriculoperitoneal shunt malfunction

OBJECTIVE

Ventriculoperitoneal (VP) shunt is the most common neurosurgical procedure to treat obstructive and communicating hydrocephalus, but failures are frequent. The most common causes of shunt failure are malpositioning and obstruction of the ventricular catheter by debris or blood clothes. The knowledge of the relationship between ventricular catheter tip position, etiology of hydrocephalus and patient's age with shunt malfunction may be useful to avoid shunt failure.

PATIENTS AND METHODS

We retrospectively analyze 89 adult patients affected by obstructive and communicating hydrocephalus operated with Ventriculoperitoneal shunt at our Institute. Patients with evident abdominal shunt malfunction were excluded from this study. Statistical analysis was performed in the group of patients with intracranial catheter malfunction in order to correlate shunt malfunction with the position of the catheter tip in brain ventricles, etiology of hydrocephalus and patient's age.

RESULTS

Shunt revision was performed in 26 patients out of 89 and cranial catheter malfunction was documented in 11 patients out of 26. Tip position in Monro foramen, lateral ventricles and third ventricle ("good position") had a lower rate of surgical shunt revision compared to septum pellucidum and wall of lateral ventricle ("bad position") p value = 0,049. No statistical significant association was observed between shunt malfunction and etiology of the hydrocephalus or patient's age.

CONCLUSIONS

Ventricular catheter tip position is one the most important factor for shunt function.

Analysis of Codman microcerebrospinal fluid shunt

INTRODUCTION

Ventriculo-peritoneal cerebrospinal fluid (CSF) shunt is the most common method of treating pediatric hydrocephalus. The Codman microadjustable valve (CMAV) is a CSF shunt constructed for children. The objective of the study was (a) to analyze complications after insertion of a CMAV shunt in hydrocephalic children, (b) to analyze complications after replacing a CMAV by an adult-type Codman Hakim adjustable valve shunt (CHAV), and to (c) analyze the in vitro characteristics of the CMAV shunt and correlate the findings with the clinical performance of the shunt.

METHODS

A retrospective study analyzed a cohort of hydrocephalic children who had received a CMAV shunt and later replaced by a CHAV shunt. We report on the complications that resulted from replacing the CMAV with the CHAV. We tested six CMAV shunts with or without an antisiphon device (ASD) in which opening pressure, resistance, sensitivity to abdominal pressure, ASD position dependency, and function were determined. The test results were correlated with the clinical performance of the shunt in the retrospective study.

RESULTS

Thirty-seven children (19 boys, 18 girls) were identified. Within the first month after shunt placement, a total of 10 patients (27%) developed complications including infections, hygromas, and shunt dysfunction. Shunt survival varied from 1 week to 145 months. Over the 10-year follow-up period, 13 children had their shunts replaced, six of them with a CHAV without any further complications. A bench test of the CMAV was done to test whether the opening pressure was in agreement with the manufacturer's specifications. Our results were generally in agreement with specifications stated by the manufacturer.

CONCLUSION

Replacing a CMAV with a CHAV was well tolerated by the patients. Bench test results were generally in agreement with manufacturers specifications. Replacing a CMAV with a CHAV in pediatric hydrocephalus patients can be accomplished safely.

Risk of failure in pediatric ventriculoperitoneal shunts placed after abdominal surgery

OBJECTIVE Experience has led us to suspect an association between shunt malfunction and recent abdominal surgery, yet information about this potential relationship has not been explored in the literature. The authors compared shunt survival in patients who underwent abdominal surgery to shunt survival in our general pediatric shunt population to determine whether such a relationship exists. METHODS The authors performed a retrospective review of all cases in which pediatric patients underwent ventriculoperitoneal shunt operations at their institution during a 7-year period. Survival time in shunt operations that followed abdominal surgery was compared with survival time of shunt operations in patients with no history of abdominal surgery. Univariate and multivariate analyses were used to identify factors associated with failure. RESULTS A total of 141 patients who underwent 468 shunt operations during the period of study were included; 107 of these 141 patients had no history of abdominal surgery and 34 had undergone a shunt operation after abdominal surgery. Shunt surgery performed more than 2 weeks after abdominal surgery was not associated with time to shunt failure (p = 0.86). Shunt surgery performed within 2 weeks after abdominal surgery was associated with time to failure (adjusted HR 3.6, 95% CI 1.3-9.6). CONCLUSIONS Undergoing shunt surgery shortly after abdominal surgery appears to be associated with shorter shunt survival. When possible, some patients may benefit from shunt placement utilizing alternative termini.

Quality of Life in Individuals Surgically Treated for Congenital Hydrocephalus During Infancy: A Single-Institution Experience

BACKGROUND

Congenital hydrocephalus (CH) is a frequently encountered birth anomaly that can hinder long-term neurologic maturity and social well-being of affected children. This study was undertaken to assess quality of life (QOL) 10-15 years after surgical treatment for primary CH during infancy at a tertiary care hospital in a developing country.

METHODS

This retrospective cohort study included individuals who presented to Aga Khan University Hospital, Karachi, Pakistan, between 1995 and 2005 at <1 year old and underwent surgery for primary CH. The Hydrocephalus Outcome Questionnaire was used to assess outcomes with respect to QOL.

RESULTS

Of 118 patients, 90 patients participated in the study. Mean age at first admission was 6.2 months. Mean length of follow-up was 5.4 years. Of these, 28 patients had died after surgery. Shunt infection (P = 0.012) and delayed milestones (P = 0.003) were found to be statistically significant factors affecting mortality in the patients who died. The mean overall health score was 0.67 ± 0.30. Age <6 months at the time of first surgery was a poor predictor of overall health on the Hydrocephalus Outcome Questionnaire (P = 0.039).

CONCLUSIONS

In our analysis, we assessed the QOL associated with CH. We hope that these results will provide insight for future prospective work with the ultimate goal of improving long-term QOL in children with CH.

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

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

Role of external ventricular drainage in the management of intraventricular hemorrhage; its complications and management

Background:

External ventricular drainage (EVD) is the procedure of choice for the treatment of acute hydrocephalus and increased intracranial pressure in patients of subarachnoid hemorrhage (SAH) and intracerebral hemorrhage with hydrocephalus and its sequelae. We evaluated the use of EVD in patients of SAHs (spontaneous/posttraumatic with/without hydrocephalus), hypertensive intracerebral bleeds with interventricular extensions, along with evaluation of the frequency of occurrence of complications of the procedure, infectious and noninfectious, and their management.

Methods:

During the period of 2½ years, between September 2012 and February 2015, 130 patients were subjected to external drainage procedure and were prospectively enrolled in this study. Information was collected on each patient regarding age, sex, diagnosis, underlying illness, secondary complications, other coexisting infections, use of systemic steroids, antibiotic treatment (systemic and intraventricular), and whether any other neurosurgical procedures were performed within 2 weeks of EVD insertion or any time the duration of ventriculostomy.

Results:

The study population of 130 patients underwent a total of 193 ventriculostomies. Thirty-six patients had ventriculostomy infection (27.6%). Evaluation of the use of EVD was done by comparing preoperative and postoperative grading scores. Forty-nine patients survived and improved their score from Grade 3–5 to Grade 2–4. Twenty-nine patients were moderately disable, 16 were severely disable, and 5 were left in the vegetative state. Evaluation of outcome of patients revealed that there was an overall mortality of 61 (46.9%) patients both in the acute phase and later. 33 of the 39 patients having Glasgow Coma Score (GCS) 3–5 at the time of EVD insertion expired, as against 20 of the 51 patients in GCS 6–8. Patients in GCS 9–12 had an even better outcome, with 8 of the 35 patients in this group expiring.

Conclusions:

The use of EVD should be undertaken only in situation where it is absolutely necessary and ventriculostomy should be kept only for the duration required, and this should be monitored on a daily basis, given the exponential increase in infection after 5 days.

How frequently external ventricular drainage device should be changed in children with ventriculoperitonel shunt infection?

Objective:

The purpose of the presenting study was to determine how frequently external ventricular drainage (EVD) device should be changed in children with ventriculopertienal shunt (VPS) infection during prolonged intravenous antimicrobial therapy.

Methods:

In this retrospective study, 25 children with VPS infection were evaluated between January 2012 and December 2013. In these children VPS was surgically removed and appropriate antimicrobial therapy was administered according to cerebrospinal culture results. Data noted about how frequently EVD device had been changed, the number of cells on direct observation of cerebrospinal fluid (CSF), glucose and protein levels of CSF, and CSF culture results were obtained from patients’ records.

Results:

Total 25 children were included in the study. The median age was three months (1 and 65 months). In 44% of children, Staphylococcus epidermidis was isolated. During treatment period, EVD catheter has changed one to six times. A total of 68 EVD catheters were changed in these patients. When the duration of ventriculostomy catheter and leukocyte count in CSF were evaluated on daily basis, leukocyte count was decreased 5 units per day in children whose catheter remained less than 10 days. However, in children whose catheter remained more than 10 days leukocyte count was decreased 2.21 units per day.

Conclusions:

In children with VPS infection, EVD device should be changed at every 10 days for the rapid resolution of the infection.

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.

The association between dental health and procedures and developing shunt infections in pediatric patients

OBJECT

Cerebrospinal fluid-diverting shunts are often complicated by bacterial infections. Dental procedures are known to cause transient bacteremia that could potentially spread hematogenously to these implanted devices. No literature currently exists to inform practitioners as to the need for prophylactic antibiotics for patients who possess these implants. The authors performed a retrospective study to assess whether dental procedures and poor oral health were associated with a higher likelihood of developing CSF-diverting shunt infections.

METHODS

Neurosurgical and pediatric dental records from January 2007 to December 2012 were reviewed for shunt surgeries and dental encounters. Indications for shunt surgery and infection rates were recorded. Dental records were reviewed for several markers of overall dental health, such as a DMFT (decayed, missing, and filled teeth) score and a gingival health/oral hygiene score. The association between these scores and the incidence of shunt infections were studied. Moreover, the relationship between the incidence of shunt infections and the timing and invasiveness of preceding dental encounters were analyzed.

RESULTS

A total of 100 pediatric patients were included in our study, for a total of 204 shunt surgeries. Twenty-one shunt infections were noted during the 6-year study period. Five of these shunts infections occurred within 3 months of a dental procedure. The odds ratio (OR) of developing a shunt infection within 3 months of a dental procedure was 0.98 (95% confidence interval [CI] 0.27-3.01), and was not statistically significant. The OR of developing a shunt infection after a high-risk dental procedure compared with a low-risk dental procedure was 1.32 (95% CI 0.02-16.29), and was not statistically significant. There was no significant association between measures of dental health, such as DMFT and gingival health score, and the likelihood of developing a shunt infection. The ORs for these 2 scores were 0.51 (95% CI 0.04-4.96) and 1.58 (95% CI 0.03-20.06), respectively. The study was limited by sample size.

CONCLUSIONS

Dental health status and the number and type of dental procedures performed do not appear to confer a higher risk of developing a CSF-diverting shunt infection in this pediatric population.

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.

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

OBJECT

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cost analysis of antibiotic-impregnated catheters in the treatment of hydrocephalus in adult patients

OBJECTIVE

To determine if use of antibiotic-impregnated shunt (AIS) systems to reduce cerebrospinal fluid (CSF) shunt infections in adult patients with hydrocephalus has been cost-effective at one institution.

METHODS

All adult patients undergoing CSF shunt insertion over a 7-year period at the Johns Hopkins Hospital were retrospectively reviewed (2004-2009). In 2006, a categorical switch to AIS catheters was made. Before 2006, standard nonimpregnated shunt catheters were used. The 1-year incidence of shunt infection was retrospectively assessed and accounting and billing records were reviewed to determine shunt infection-related medical costs for patients undergoing AIS vs non-AIS shunt surgery.

RESULTS

A total of 500 (250 AIS, 250 non-AIS) shunt surgeries were performed for normal-pressure hydrocephalus (NPH) (n = 378 [76%]), pseudotumor cerebri (n = 83 [17%]), and various obstructive and communicating hydrocephalus etiologies (n = 40 [8%]). The incidence of shunt infection was decreased in the AIS (1.2%) vs non-AIS (4.0%) cohorts (P = .0492. Overall, the mean cost per shunt infection was $40,371. Per 250 shunts placed, the total infection-related cost was reduced from $321,407 to $203,424 after the conversion to AIS catheters. AIS catheters were associated with direct cost savings of $47,193 per 100 shunt surgeries performed.

CONCLUSIONS

In a retrospective cohort study of 500 CSF shunt surgeries performed in adult patients with hydrocephalus, this institution's categorical conversion to AIS catheters was associated with a significant reduction in infection-related medical costs within the first year after surgery. Although prospective randomized cost-utility studies are needed to confirm these observations, these results suggest that AIS catheters are cost-effective in the treatment of hydrocephalus in adult patients.

Endoscopic third ventriculostomy versus ventriculoperitoneal shunt in the treatment of obstructive hydrocephalus due to posterior fossa tumors in children

OBJECT

This study compares endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) in the treatment of pediatric patients with marked obstructive hydrocephalus due to midline posterior fossa tumors.

METHODS

Fifty-three pediatric patients with a midline posterior fossa tumor (32 medulloblastomas and 21 ependymomas) associated with marked hydrocephalus were studied. Patients were divided into two groups: group A (32 patients) operated by ETV with a mean follow-up of 27.4 months and group B (21 patients) operated by VPS with a mean follow-up of 25 months.

RESULTS

Both procedures proved to be effective clinically and radiologically. In group A, intraoperative bleeding occurred in two cases (6.2%) and cerebrospinal fluid leakage in one case (3.1%). In group B, shunt infection occurred in two cases (9.4%), one of these two cases died 4.5 months postoperatively from ventriculitis. Subdural collection occurred in two cases (9.4%), epidural hematoma in one case (4.7%), and upward brain herniation in one case (4.7%). Endoscopic third ventriculostomy proved to be superior due to shorter duration of surgery (15 min versus 35 min), lower incidence of morbidity (9.3% versus 38%), no mortality (0% versus 4.7%), and lower incidence of procedure failure (6.2% versus 38%).

CONCLUSION

The shorter duration of surgery, the lower incidence of morbidity, the absence of mortality, the lower incidence of procedure failure, and the significant advantage of not becoming shunt dependent make ETV be recommended as the first choice in the treatment of pediatric patients with marked obstructive hydrocephalus due to midline posterior fossa tumors.

Timing of ventriculoperitoneal shunt insertion following spina bifida closure in Kenya

PURPOSE

In Western medical centers, emphasis has been placed on simultaneous myelomeningocele closure and ventriculoperitoneal shunting for children with spina bifida (SB) and co-morbid hydrocephalus (HC). This is not practical in developing countries where patients present in a delayed fashion, many with open, dirty myelomeningoceles. The purpose of this study was to evaluate whether timing of shunting in relation to myelomeningocele closure affected shunt-related complications such as SB wound infection, shunt infection, and shunt malfunction.

METHODS

A retrospective analysis was undertaken of all SB patients undergoing ventriculoperitoneal shunting within 11 days following myelomeningocele closure at Kijabe Hospital between 1997 and August 2007. Data were collected from hospital records and analyzed in SPSS.

RESULTS

Over the study period there were 276 patients included. Eighteen patients were shunted prior to SB closure and 13 patients had simultaneous shunting and SB closure. Patients shunted prior to, simultaneously, or within the first 4 days after SB closure had a fivefold higher shunt infection rate (23%) than those shunted 5-10 days following SB closure (4.7%) (p < 0.0001). Shunt malfunctions were also significantly higher in the group shunted prior to back closure (33.3%) vs. those shunted simultaneously (15.4%) or within the first 10 days following SB closure (13.9%) (p = 0.0001). No difference was seen in these groups with regard to wound infections. No difference in shunt-related complications was observed between those shunted 5 to 10 days following back closure.

CONCLUSIONS

This study indicates that in developing countries, patients with SB who present in a delayed fashion but require shunting and have sterile CSF, should have their shunts inserted 5-10 days after SB closure.

Hospital costs associated with shunt infections in patients receiving antibiotic-impregnated shunt catheters versus standard shunt catheters

BACKGROUND

The average hospital cost for shunt infection treatment is $50,000, making it the most financially costly implant-related infection in the United States. We set out to determine whether introduction of antibiotic-impregnated shunts (AISs) in our practice has decreased the incidence of shunt infection or decreased infection-related hospital costs at our institution.

METHODS

Clinical and hospital billing records of pediatric patients undergoing cerebrospinal fluid (CSF) shunt insertion at a single institution from April 2001 to December 2006 were retrospectively reviewed. Eighteen months before October 2002, all CSF shunts included standard, non-AIS catheters. During the 4 years after October 2002, all CSF shunts included AIS catheters. Patients were followed at least 18 months after surgery.

RESULTS

A total of 406 pediatric patients underwent 608 shunt placement procedures (400 AISs, 208 non-AISs). Of patients with non-AIS catheters, 25 (12%) experienced shunt infection, whereas only 13 patients (3.2%) with AIS catheters experienced shunt infection during follow-up (P < .001). The total hospital cost to treat 25 non-AIS shunt infections over the first 18 months was $1,234,928. The total hospital cost to treat 13 AIS shunt infections over the past 4 years was $606,328. The mean hospital cost per shunt infection was similar for infected AIS and non-AIS catheters ($46,640 vs. $49,397). However, the infection-related hospital cost per 100 patients shunted was markedly lower in the AIS cohort than in the non-AIS cohort ($151,582 vs. $593,715).

DISCUSSION

The introduction of AIS catheters in our institutional practice reduced the incidence of shunt infection and resulted in significant hospital cost savings. AIS systems are efficient and cost-effective instruments to prevent perioperative colonization of CSF shunt components.

Postoperative cerebrospinal fluid wound leakage as a predictor of shunt infection: a prospective analysis of 205 cases. Clinical article

OBJECT

The purpose of this study was to audit some of the risk factors for CSF shunt infections within the authors' practice and analyze the statistical significance of these factors.

METHODS

The authors used their own contemporaneously collected shunt database in this study. All shunt procedures performed over a 2-year period between March 2000 and February 2002 at Great Ormond Street Hospital, London, were analyzed. For the purposes of this study, positive CSF cultures were a prerequisite for a data set to qualify as a shunt infection. The authors studied the effects of patient age, the etiology of hydrocephalus, whether the surgery was primary shunt placement versus a revision, the surgeon's level of experience, whether the surgery was performed on an elective or emergency basis, and the presence or absence of a perioperative CSF leak. Statistical analyses were performed.

RESULTS

Two hundred and five patients with a mean (+/- SD) age at surgery of 27.9 +/- 43.0 months were included in this study. Shunt infections developed in 17 patients (8.3%) at a median of 42 days postoperatively (range 14-224 days). The presence of a perioperative CSF leak was the only variable that showed a statistically significant association with the occurrence of a shunt infection, with an infection rate of 57.1% compared to 4.7% in cases with no leak (OR 27.0 [95% CI 7.7-94.3]). The cause of hydrocephalus, elective versus emergency surgery, level of surgeon experience, a primary versus a revision procedure, and patient age did not have a bearing on the infection risk.

CONCLUSIONS

The presence of a perioperative CSF leak puts pediatric patients at a very high risk of shunt infection. Aside from prevention, the optimal management of such CSF leaks require further investigation.

Comparison of shunt infection incidence in high-risk subgroups receiving antibiotic-impregnated versus standard shunts

BACKGROUND

Shunt infection is a morbid complication of CSF shunting. Though antibiotic-impregnated shunt (AIS) systems decrease shunt infections by preventing bacterial colonization following device implantation, their effectiveness in populations at high risk for infection has recently been disputed. We set out to determine whether the categorical switch to AIS systems at our institution has resulted in a decreased incidence of shunt infection in high-risk pediatric patients.

METHODS

We retrospectively reviewed the records from all pediatric patients undergoing CSF shunt procedures at The Johns Hopkins Hospital over a 10-year period between January 1997 and December 2007. During the 5.75 years prior to October 2002, all CSF shunts included standard, non-AIS catheters. During the 4.25 years after October 2002, all CSF shunts included AIS catheters. High-risk subgroups were defined a priori as prematurity (<35 weeks gestational age), shunts placed immediately post-meningitis, conversion of external ventricular drains (EVD) to shunt, and replacement of nosocomial shunt infection in patients requiring prolonged hospital stay (>1 month).

RESULTS

A total of 544 pediatric patients underwent 1,072 shunt placement procedures (502 AIS, 570 non-AIS). Of patients with non-AIS catheters, 64 (11.2%) experienced shunt infection, whereas only 16 (3.2%) patients with AIS catheters experienced shunt infection (p<0.001). AIS versus non-AIS was associated with decreased shunt infection in premature neonates [three (5.5%) vs. seven (20.0%), p=0.030], acutely following bacterial meningitis [two (5.7%) vs. nine (25.0%), p=0.043], when converting EVD to shunts [zero (0%) vs. four (13.3%), p=0.030], and in patients with prolonged hospital stay>1 month [three (5.3%) vs. 12 (18.5%), p=0.022]. Staphylococcus aureus was the most common infectious agent for both non-AIS (81.3%) and AIS (75.0%) systems.

CONCLUSION

The introduction of AIS catheters into our institutional practice has reduced the incidence of shunt infection in pediatric populations at highest risk for infection. AIS catheters are effective instruments to prevent peri-operative colonization of CSF shunt components.

An experimental in-vivo canine model for adult shunt infection

Background

Detailed human studies of the mechanisms and development of shunt infection in real time are not possible, and we have developed a canine hydrocephalus model to overcome this. The intention of this pilot study was to show that the canine hydrocephalus model could be shunted using conventional "human" shunts, and that a shunt infection could be established so that further studies could then be planned.

Methods

Hydrocephalus was induced in seven dogs (Canis familiaris) by fourth ventricle obstruction. Four weeks later they were shunted using a Hakim Precision valve. Four of the dogs received shunts whose ventricular catheter had been inoculated with Staphylococcus epidermidis, and three were uninoculated controls. Four weeks after shunting the dogs were sacrificed and necropsy was performed. Removed shunts and tissue samples were examined microbiologically and isolates were subjected to detailed identification and genomic comparison.

Results

All the dogs remained well after shunting. Examination of removed shunt components revealed S. epidermidis in the brain and throughout the shunt system in the four inoculated animals, but in two of these Staphylococcus intermedius was also found. S. intermedius was also isolated from all three "negative" controls. There were slight differences between S. intermedius strains suggesting endogenous infection rather than cross- infection from a point source.

Conclusion

Shunt infection was established in the canine model, and had the experiment been extended beyond four weeks the typical microbiological, pathological and clinical features might have appeared. The occurrence of unplanned shunt infections in control animals due to canine normal skin flora reflects human clinical experience and underlines the usual source of bacteria causing shunt infection.

Antimicrobial suture wound closure for cerebrospinal fluid shunt surgery: a prospective, double-blinded, randomized controlled trial

OBJECT

Implantation of cerebrospinal fluid (CSF) shunting devices is associated with a 5-15% risk of infection as cited in contemporary pediatric neurosurgical literature. Shunt infections typically require complete removal of the device and prolonged antibiotic treatment followed by shunt replacement. Moreover, shunt infections are commonly associated with prolonged hospital stays, potential comorbidity, and the increased risk of neurological compromise due to ventriculitis or surgical complications. The authors prospectively evaluated the incidence of CSF shunt infection following shunt procedures performed using either antimicrobial suture (AMS) or conventional suture.

METHODS

In a single-center, prospective, double-blinded, randomized controlled trial, the authors enrolled 61 patients, among whom 84 CSF shunt procedures were performed over 21 months. Randomization to the study (AMS) or control (placebo) group was stratified to minimize the effect of known shunt infection risk factors on the findings. Antibacterial shunt components were not used. The primary outcome measure was the incidence of shunt infection within 6 months of surgery.

RESULTS

The shunt infection rate in the study group was 2 (4.3%) of 46 procedures and 8 (21%) of 38 procedures in the control group (p = 0.038). There were no statistically significant differences in shunt infection risk factors between the groups (procedure type and time, age < 6 months, weight < 4 kg, recent history of shunt infection). No suture-related adverse events were reported in either group.

CONCLUSIONS

These results support the suggestion that the use of AMS for CSF shunt surgery wound closure is safe, effective, and may be associated with a reduced risk of postoperative shunt infection. A larger randomized controlled trial is needed to confirm this association.

Clinical and economic consequences of antibiotic-impregnated cerebrospinal fluid shunt catheters

OBJECT

The authors evaluated the safety and efficacy of antibiotic-impregnated shunt catheters (AISCs) and determined the cost-benefit ratio related to the fact that AISCs increase the implant costs of a shunt procedure by approximately $400 per patient.

METHODS

The control group comprised 98 adults with chronic hydrocephalus and 22 children, who were treated without AISCs (non-AISCs). In the treatment group, AISCs (Bactiseal, Codman, Johnson & Johnson) were implanted in 171 adults and 26 children. The minimum follow-up period was 6 months.

RESULTS

Important risk factors for shunt infections (such as age, comorbidity, cause of hydrocephalus, operating time, and duration of external cerebrospinal fluid drainage prior to shunt placement) did not differ between the study and control groups. In the pediatric AISC group, the frequency of premature, shunt-treated infants and the incidence of external ventricular drainage prior to shunt insertion were actually higher than those in the non-AISC group. When using AISCs, the shunt infection rate dropped from 4 to 0.6% and from 13.6 to 3.8% in the adult and the pediatric cohort, respectively. Overall the infection rate decreased from 5.8 to 1%, which was statistically significant (p = 0.0145). The average costs of a single shunt infection were $17,300 and $13,000 in children and adults, respectively. The cost-benefit calculation assumed to have saved shunt infection-related costs of approximately $50,000 in 197 AISC-treated patients due to the reduction in shunt infection rate in this group compared with costs in the control group. Despite the incremental implant costs associated with the use of AISCs, the overall reduction in infection-related costs made the use of AISCs cost beneficial in the authors' department.

CONCLUSIONS

From clinical and economic perspectives, AISCs are seemingly a valuable addition in hydrocephalus therapy.

Sterile surgical technique for shunt placement reduces the shunt infection rate in children: preliminary analysis of a prospective protocol in 115 consecutive procedures

OBJECTIVE

The objective of this study was to evaluate whether the rigid application of a sterile protocol for shunt placement was applicable on a routine basis and allowed the reduction of shunt infections (SI) in children.

MATERIALS AND METHODS

Since 2001, a rigid sterile protocol for shunt placement in children using neither antibiotic-impregnated catheters nor laminar airflow was prospectively applied at Erasme Hospital, Brussels, Belgium. For assessing the protocol efficacy before continuation, we preliminarily analyzed the results of the first 100 operated children (43 females, 57 males, 49 aged <12 months; 115 consecutive shunt placement/revision procedures). All procedures were performed by the same senior surgeon, one assistant, one circulating nurse, one anesthesiologist. The sterile protocol was rigidly imposed to these four staff members: uniformed surgical technique; limited implant and skin edge manipulation; minimized human circulation in the room; scheduling surgery as first morning operation; avoiding postoperative cerebrospinal fluid (CSF) leak; double gloving; procedures of less than 30-min duration; systemic antibiotics prophylaxis. We analyzed separately: (1) children carrying an increased risk of SI (n = 38) due to preoperative external ventricular drainage, CSF leak, meningitis, glucocorticoids, chemotherapy; (2) children aged <12 months; (3) procedures for shunt revision.

RESULTS

Errors in protocol application were recorded in 71/115 procedures. They were mainly done by non-surgical staff, decreased with time and were medically justified in some young children. Surprisingly, no SI occurred (follow-up, 4 to 70 months). One child developed an appendicitis with peritonitis (Streptococcus faecalis) after 6 months. No SI was found. After peritonitis was cured, shunt reinsertion was uneventful.

CONCLUSION

These preliminary results suggest that a uniform and drastic sterile surgical technique for shunt placement: (1) can be rigidly applied on a routine basis; (2) can lower the early SI rate below 1%; (3) might have a stronger impact to reduce SI than using antibiotic-impregnated catheters and optimizing the operative environment such as using laminar airflow and reducing the non-surgical staff. This last issue will be evaluated further in the present ongoing protocol.

Effect of shunt catheter on the systemic immune response: evaluation of neutrophil count, function, and rate of chemotaxis

OBJECT

The localized impairment of the host defense mechanism due to the presence of a shunt apparatus has been suggested as a risk factor for shunt infection. The purpose of this study was to evaluate the probable systemic effect of a shunt catheter on neutrophil phagocytosis and chemotaxis in vivo.

METHODS

Twenty-four children with hydrocephalus who were referred to the Children's Hospital Medical Center in Tehran for ventriculoperitoneal shunt placement were included in this study. Neutrophil count, chemotaxis, and nitroblue tetrazolium (NBT) tests were performed before and 2 months after the operation. In comparing the preoperative neutrophil count, NBT percentage, and chemotaxis (with and without the addition of a chemoattractant factor) with these same factors postoperatively, the authors found no statistically significant differences. In four children, shunt infections developed during the follow-up period. There were no significant differences between the aforementioned parameters in children with infected shunts and those with uninfected shunts.

CONCLUSIONS

The results of this study do not support the idea of systemic impairment of neutrophils after shunt insertion. Further studies with more specific methods are required to elaborate on this issue.

Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients

BACKGROUND

Shunt infection in hydrocephalus patients is a severe, even life-threatening complication. Antibiotic-impregnated shunts (AIS) have been developed in an attempt to reduce rate of shunt infection. The study was performed to analyze if AIS can diminish the rate of shunt infection. The pathogenic nature of shunt infection in patients with AIS systems and those without antibiotic impregnated shunts (non-AIS) was compared.

METHODS

Over a period of 24 months in the Department of Neurosurgery at University Hospital of Tübingen shunt surgery was performed in 258 patients. In 86 patients AIS systems were implanted. Shunt catheters were commercially impregnated with clindamycin and rifampicin. Analysis of the clinical data included sex, age, classification of hydrocephalus, shunt types and risk factors for shunt infection [age (< 1 year and > 80 years), prematurely born patients, external ventricular drainage, former shunt infection, former systemic infection, disturbance of consciousness, former radiation-/chemotherapy]. Infection rates and underlying bacterial pathogens of patients with AIS were compared to patients with implanted non-AIS systems (172 patients).

RESULTS

AIS and non-AIS patients did not differ in sex, etiology of hydrocephalus and the shunt type. In the AIS group 72 out of 86 patients had at least one risk factor (83.7 %), compared to 126 patients in the non-AIS group (73.3 %). There was no significant difference between the two groups (p = 0.0629; Fisher's exact test). In patients with no risk factors, only one patient with non-AIS suffered from shunt infection. In patients with one or more risk factors the rate for shunt infection was 7.14 % in patients with non-AIS and 6.94 % in patients with AIS. Former shunt infection (p = 0.0124) was related to higher risk for shunt infection. The use of AIS had therefore no significant advantage (p = 0.8611; multiple logistic regression). Significantly related to a shunt infection was the number of shunt surgeries. 190 interventions in the AIS group (2.21 interventions per patient) and 408 in the non-AIS group (2.37 interventions per patient) had been performed (p = 0.3063; Wilcoxon). There was no shunt infection in the group of patients on whom only one shunt surgery was performed. In patients with at least two shunt surgeries the infection rate was 9%. The infection rate in AIS patients was 5/52 (9.6 %) and in the non-AIS 10/114 (8.77 %), (p = 1.0; Fisher's exact test). Staphylococcus epidermidis was the most frequent pathogen for shunt infection. Fourteen out of 15 infections occurred within the first 6 months of surgery. The most frequent pathogen for shunt infection was S. epidermidis. No toxic or allergic complications were seen using the AIS shunt systems. The presented data show a remarkably low infection rate of 5.8 % in the non-AIS group compared to other studies which demonstrated a significant decrease in the infection rate by AIS.

CONCLUSION

AIS did not significantly reduce shunt infection in hydrocephalus patients in the presented study. In the AIS group three patients suffered from shunt infections caused by skin ulceration or neurosurgical procedures with exposure of the cerebrospinal liquor after shunt implantation. AIS was not developed to prevent infection in such cases, therefore an advantage of AIS can not be excluded. In view of the presented data and the small number of reported studies a prospective randomized multicenter study is required.

Observations regarding failure of cerebrospinal fluid shunts early after implantation

✓Despite advances in cerebrospinal fluid (CSF) diversionary techniques, shunt failure due to infection or malfunction remains a persistent problem in hydrocephalus care. The aim of this study was to evaluate the independent predictors of early shunt survival after implantation in a large cohort of patients. The authors retrospectively reviewed the records of all patients who had undergone shunt implantation procedures at their institution during an 8-year period. They analyzed the independent predictors of shunt survival in 116 failed shunt placement procedures (infection or malfunction) by performing univariate and multivariate factorial analyses. Analysis of the 116 failed shunts in the 396 new shunt placement procedures performed revealed that age was a significant independent predictor of shunt survival time in failures due to malfunction (p < 0.05) as well as infection (p < 0.05). In addition, a significant relationship between patient race and shunt survival was also found. As suggested by data in other studies focused on this outcome, early shunt failure occurs sooner in younger patients. Interestingly, this study is one of few whose data have revealed that race may affect shunt failure after implantation. Specifically, shunt failure due to infection resulted in significantly shorter shunt survival time in non-white patients compared with that in white patients. Among the shunts that failed due to malfunction, however, white patients had shorter shunt survival times.

Shunt infection: is there a near-miss scenario?

OBJECT

The aim of this study was to establish whether microbiological contamination at the time of shunt insertion can be detected and used to predict the likelihood of subsequent shunt infection.

METHODS

A prospective study of pediatric patients undergoing primary shunt insertion was undertaken. Following the protocol devised for this study, three swab samples were collected from the surgical wounds during each procedure. These samples were incubated and subcultured, and the isolates were identified and stored. In patients who subsequently presented with clinical evidence of shunt infection, cerebrospinal fluid (CSF) was analyzed using microscopy, tissue cultures, and sensitivity testing. The organisms isolated at the time of shunt insertion and those responsible for subsequent shunt infection were then compared. The study population consisted of 107 pediatric patients. Because one patient underwent placement of an additional contralateral shunt system, there were 108 total shunt insertions yielding 325 swab samples. Organisms were identified in cultures of 50 swab samples (15%) obtained in 40 patients (37%). In seven of these 40 patients (17.5%) a CSF infection subsequently developed. In only one patient was the infectious organism the same as that isolated from the swab specimens. In an additional six patients (8.8%) a CSF infection occurred despite the lack of growth in the cultures from intraoperative swab samples.

CONCLUSIONS

The organisms responsible for shunt infection were rarely detected in the operative wound at the time of shunt insertion, leading the authors to conclude that the vulnerable period for bacterial colonization of shunts may not be restricted to the operative procedure as is commonly believed, but may extend throughout the postoperative period of wound healing. These findings have implications not only for a better understanding of the cause of shunt infections but also for the development of strategies to prevent them.

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

BACKGROUND AND OBJECTIVE

The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options.

MATERIALS AND METHODS

The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis.

RESULTS

The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases.

CONCLUSIONS

Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.

Shunts vs endoscopic third ventriculostomy in infants: are there different types and/or rates of complications? A review

INTRODUCTION

The decision-making process when we compare endoscopic third ventriculostomy (ETV) with shunts as surgical options for the treatment of hydrocephalus in infants is conditioned by the incidence of specific and shared complications of the two surgical procedures.

REVIEW

Our literature review shows that the advantages of ETV in terms of complications are almost all related to two factors: (a) the avoidance of a foreign body implantation and (b) the establishment of a 'physiological' cerebrospinal fluid (CSF) circulation. Both these kinds of achievements are particularly important in infants because of the relative high rate of some intraoperative (i.e. abdominal) and late (secondary craniosynostosis, slit-ventricle syndrome) shunt complications in this specific subset of patients. On the other side, the main factor which is claimed against ETV is the relatively high risk of immediate mortality and neurological complications. Clinical manifestations of neurological structure damage seem to be more frequent in infants, probably due to the more relevant effect of parenchymal and vascular damage in this age group; however, both the immediate mortality and neurological damage risk of ETV procedures should be weighted against the long-term mortality and the late neurological damage which is not infrequently described as a consequence of shunt malfunction and proximal shunt revision procedures. Infections are possible in both ETV and extrathecal CSF procedures, especially in infants. However, the incidence of infective complications is significantly lower in case of ETV (1-5% vs 1-20%). Moreover, different from shunting procedures, infections in children with third ventriculostomy have a more benign course, being generally controlled by antibiotic treatment alone.

Are higher vancomycin doses needed in venticle-external shunted patients?

OBJECTIVE

Hydrocephalus is usually resolved by diverting cerebrospinal fluid through a surgically implanted intra-ventricular catheter (shunt). The aim of this study was to characterize vancomycin pharmacokinetic (PK) parameters and optimal dosage in shunted patients under vancomycin treatment.

SETTING

Intensive Care and Neurosurgical Units. University Hospital.

METHODS

Retrospective data of vancomycin blood concentrations, demographics and biochemical parameters, from a Therapeutic Drug Monitoring (TDM) program, in ventricle-external shunted patients (Group A) and controls (Group B) were collected. In all subjects, several blood samples at steady state conditions were drawn. Individual PK parameters such as drug clearance (CL) and volume of distribution (V) were estimated by using an one-compartmental PK model and later, dosage regimens were individually adjusted by Bayesian analysis. The obtained CL and V mean +/- standard deviation were compared between both groups (A versus B). Vancomycin dosage regimens between both groups were also compared.

MAIN OUTCOME MEASURES

Patients demographics, clinical records, creatinine clearance by Cockcroft-Gault, vancomycin blood levels, vancomycin pK parameters and optimal initial IV vancomycin dosage.

RESULTS

Forty-five patients were included in the study: 15 patients in group A and 30 subjects in group B. Significant differences between CL(A) and CL(B) means were observed, while not between V(A) and V(B). In shunted patients, the required vancomycin daily dose to reach target concentrations was significantly higher than the dose needed in the control group (49.25 +/- 12.28 mg/kg/day vs. 31.74 +/- 6.70 mg/kg/day; P < 0.0005).

CONCLUSIONS

Greater vancomycin clearance was found in our shunted patients, thus they required higher vancomycin daily doses compared to the control group. Consequently, vancomycin TDM in shunted patients should be advisable in order to guarantee antibiotic blood concentrations within the recommended therapeutic range.

Evaluation and management of shunt infections in children with hydrocephalus

Shunt infections constitute one of the main risks of shunt surgery for hydrocephalus, which is the single most common type of surgery performed by pediatric neurosurgeons. Infectious complications are responsible for increased morbidity and mortality, lengthy hospitalizations, and high cost. Most modern series report infection rates approaching 10% of all shunt procedures. Despite the high incidence of this complication, optimal management is still unknown, and research on prevention has been hampered by single-institution series and small numbers. This article will review the history, causes, presentation, management, and outcome from shunt infections in children. Pitfalls in diagnosis and management will be reviewed. Finally, prevention strategies and research questions still remaining in this area will be outlined.

Effect of surface proteins on Staphylococcus Epidermidis adhesion and colonization on silicone

Shunt infections are one of the most serious complications in shunt implant surgery. Previous studies have suggested that cerebrospinal fluid (CSF) proteins could affect bacterial adhesion and subsequent shunt infection. A systematic study using immobilized protein on the surface of silane-modified silicone was conducted to determine how these modifications influenced Staphylococcus epidermidis adhesion and colonization. A comparison was also made with silicone having physically adsorbed protein. A colony-counting adhesion assay and scanning electron microscopy (SEM) were used to provide quantitative analysis of bacterial adhesion and semi-quantitative analysis of bacterial colonization, respectively. In order to determine the appropriate silanization process for effective protein immobilization, the effect of bovine serum albumin (BSA) immobilized on n-3-(trimethoxysilyl)propyl-ethylenediamine (AEAPS)/silicone, aminopropyltriethoxysilane (APTMS)/silicone, 3-(glycidyloxypropyl)trimethoxysilane (GPTMS)/silicone, and octadecyltrichlorosilane (OTS)/silicone on bacterial adhesion was investigated. Upon identifying that OTS is the most effective silane, different types of proteins, including: BSA, human serum albumin (HSA), gamma-globulin, and fibrinogen were immobilized on OTS/silicone by a photo-immobilization method. Immobilized protein on modified silicone surfaces was found to be stable in saline for 30 days, while physically adsorbed protein showed instability within hours as determined by contact angle measurements and X-ray photoelectron spectroscopy (XPS). For HSA/OTS/silicone, BSA/OTS/silicone, gamma-globulin/OTS/silicone, fibrinogen/OTS/silicon, and physically absorbed BSA on silicone, the contact angles were 78.5 degrees, 80.7 degrees, 78.9 degrees, 81.3 degrees, and 96.5 degrees; and the amount of nitrogen content was found to be 4.6%, 5.0%, 5.6%, 7.2%, and 3.2%, respectively. All protein immobilized on OTS/silicone surfaces significantly reduced bacterial adhesion by around 75% compared to untreated silicone, while physically adsorbed BSA on silicone reduced by only 29.4%, as determined by colony-counting adhesion assay. However, there was no significant difference on bacterial adhesion among the different types of proteins immobilized on OTS/silicone. Minimizing bacterial adhesion and colonization can be attributed to the increased concentration of -NH2 group, and stability and more hydrophilic nature of the protein/OTS/silicone surfaces.

The International Infant Hydrocephalus Study: concept and rational

INTRODUCTION

During the recent meetings of the International Study Group on Neuroendoscopy and the International Society for Pediatric Neurosurgery, the consensus view emerged that there is a need to assess the value and efficacy of neuroendoscopic procedures against shunting in a scientific manner, to resolve long-lasting debates on the subject.

MATERIAL AND METHODS

A prospective randomized, controlled trial of endoscopic third ventriculostomy vs shunting in children presenting under the age of 2 years with pure aqueduct stenosis is been proposed and organized (the International Infant Hydrocephalus Study, IIHS). The participating surgeons must adhere to the philosophy of randomization and be suitably experienced in endoscopic techniques in infants. The primary outcome of the trial will be the overall health-related quality of life of these children at 5 years of age. Hence, the study is focusing on the effect of surgery on neurodevelopment, rather than the less important issue of shunt or stoma survival, that has been debated extensively with no conclusion so far. Intention-to-treat analysis will be performed according to the first surgery. Secondary outcomes such as complication and reoperation rate, total hospitalization time and cost, need for repeat imaging, and others will be analyzed as well.

RESULTS

Pure aqueduct stenosis is relatively rare, making recruitment problematic, but has been chosen to avoid other confounding factors that could influence outcome. More than 25 centers worldwide have committed already to patient recruitment to the study. It is anticipated that recruitment will last for 2 years, aiming for 91 patients per arm. The study has started recruiting patients already in some countries.

CONCLUSION

It is hoped that the trial will not only provide answers to unsettled debates on the value of neuroendoscopy but also create a network of collaborating pediatric neurosurgeons for future initiatives.

Initial experience with antibiotic-impregnated silicone catheters for shunting of cerebrospinal fluid in children

INTRODUCTION

Infection is a major complication of cerebrospinal fluid (CSF) shunting procedures. Recently, rifampin-impregnated and clindamycin-impregnated silicone catheters have been developed in an attempt to prevent and/or reduce the incidence of shunt infections. In vitro and in vivo animal studies have shown their efficacy in reducing bacterial colonization of catheters. However, these shunts are yet to be evaluated in clinical trials and their safety and efficacy in preventing shunt infections is unknown.

METHODS

Between April 2002 and April 2003, 31 children (age range 6 months to 17 years, mean 4.5 years) underwent implantation of an antibiotic-impregnated silicone catheter for CSF diversion. All surgeries were performed by a single neurosurgeon (HSM) at a single medical center. The Codman Hakim Bactiseal silicone catheter was used in all children. Thirty-two catheters were implanted in 31 children. All children have been followed since surgery (for an average of 19 months). For comparison, the previous 46 standard implanted shunts over a similar period of time were reviewed (average follow-up 31 months).

RESULTS

Of the 32 implanted catheters, 11 involved placement of a new complete shunt system, 8 were distal revisions, and 13 were proximal/ventricular revisions. There were fewer early and late complications than in the standard shunt group (12.5 and 18.8% vs. 23.9 and 34.8%). There was no local reaction from implantation of the catheters. One child contaminated his distal catheter by disrupting his abdominal incision. None of the other patients have developed any evidence of shunt infection to date.

CONCLUSION

Rifampin-impregnated and clindamycin-impregnated silicone catheters appear to be safe and well tolerated in children. Preliminary results suggest a low incidence of shunt infection. Longer follow-up and a larger number of patients are needed to more accurately assess the efficacy of these catheters compared with traditional silicone catheters.

Therapeutic vancomycin monitoring in children with hydrocephalus during treatment of shunt infections

BACKGROUND

The successful treatment of shunt infections in children with hydrocephalus is still an important problem. Diagnosis of shunt colonization is often very difficult. To treat serious central nervous system (CNS) infections, intraventricular therapy with antibiotics is necessary to reach adequate cerebrospinal fluid (CSF) concentrations and eradicate the infection. For optimal management of shunt infections the concentration of administered antibiotics in CSF should be measured. The antibiotic dosing could be modified in the individual patient after pharmacokinetic studies.

METHODS

In our studies, vancomycin was applied to 10 children with hydrocephalus (including 6 with a myelomeningocele) for therapeutic purposes in shunt infections. The drug was administered IV and/or intraventricularly. During treatment the concentration of vancomycin in CSF was determined by fluorescence polarization immunoassay (FPIA) method.

RESULTS

Considerable differences in vancomycin concentrations after the same intraventricular antibiotic administration were observed depending on the patient. The vancomycin levels determined at study state were often much higher than the therapeutic recommended range, and the biologic half-life period (T(1/2)) of vancomycin in cerebrospinal fluid after intraventricular administration was prolonged.

CONCLUSIONS

The results of our studies give information about the pharmacokinetics of vancomycin in CSF in a group of children with hydrocephalus after intraventricular administration of the drug. In our investigation, the administration of doses smaller than 5 mg/24 hours is appropriate when the removed volume of CSF will be 20 to 30 mL/24 hours.

Risk factors for pediatric ventriculoperitoneal shunt infection and predictors of infectious pathogens

Identification of risk factors for shunt infection and predictors of infectious pathogens may improve current methods to prevent and treat shunt infections. We reviewed data on 820 consecutive ventriculoperitoneal (VP) shunt placement procedures in 442 pediatric patients at our institution during 1992-1998. Ninety-two shunts (11%) developed infection a median of 19 days (interquartile range, 11-35 days) after insertion. Premature birth (relative risk [RR], 4.81; 95% confidence interval [CI], 2.19-10.87), previous shunt infection (RR, 3.83; 95% CI, 2.40-6.13), and intraoperative use of the neuroendoscope (RR, 1.58; 95% CI, 1.01-2.50) were independent risk factors for shunt infection. The bacterial organisms early after shunt surgery (<14 days) were the same as those late after shunt surgery (>14 days). As determined by an analysis of the 92 infected shunts, hospital stay of >3 days at the time of shunt insertion (odds ratio [OR], 5.27; 95% CI, 1.15-25.3) and prior Staphylococcus aureus shunt infection (OR, 5.91; 95% CI, 1.35-25.9) independently increased the odds that S. aureus was the causal pathogen.

Cerebrospinal fluid shunt infection: a prospective study of risk factors

OBJECT

Hydrocephalus is a common condition of childhood that usually requires insertion of a cerebrospinal fluid (CSF) shunt. Infection is one of the most devastating complications that may arise from the presence of CSF shunts. In this study, the authors prospectively analyzed perioperative risk factors for CSF shunt infection in a cohort of children.

METHODS

Between 1996 and 1999, 299 eligible patients underwent CSF shunt operations (insertions and revisions) that were observed by a research nurse at a tertiary care pediatric hospital. Several perioperative variables were recorded. All cases were followed postoperatively for 6 months to note any development of CSF shunt infection. A Cox proportional hazards model was used to analyze the relationship between the variables and the development of shunt infection. Thirty-one patients (10.4%) experienced shunt infection. Three perioperative variables were significantly associated with an increased risk of shunt infection: 1) the presence of a postoperative CSF leak (hazard ratio [HR] 19.16, 95% confidence interval [CI] 6.96-52.91); 2) patient prematurity (< 40 weeks' gestation at the time of shunt surgery: HR 4.72, 95% CI 1.71-13.06), and 3) the number of times the shunt system was inadvertently exposed to breached surgical gloves (HR 1.07, 95% CI 1.02-1.12).

CONCLUSIONS

Three variables associated with an increased incidence of shunt infection have been identified. Changes in clinical practice should address these variables, as follows. 1) Great care should be taken intraoperatively to avoid a postoperative CSF leak. 2) Alternatives to placement of a CSF shunt in premature infants should be studied. 3) Surgeons should minimize manual contact with the shunt system and consider the use of double gloves.

Adhesion of staphylococci to polymers with and without immobilized heparin in cerebrospinal fluid

Infections of cerebrospinal fluid (CSF) shunts constitute a serious clinical problem. The role of adhesion by coagulase negative staphylococci, the most common etiological agent, was examined in vitro to polyvinyl chloride (PVC), silicone, and to PVC and silicone with end-point attached (EPA) heparin. These are flexible materials commonly used in neurosurgical implants. Bacterial adhesion was quantitated by bioluminescence. The bacterial adhesion to biomaterial surfaces increased with increasing concentrations of bacterial cells. Scatchard plot analysis showed continuous negative (concave) slopes, indicating multiple interactions between biomaterial and bacteria. The thermodynamic studies showed a positive value of the standard entropy change at 37 degrees C, which indicates that hydrophobic interactions are important in bacterial adhesion to polymers. Incubation with CSF for 1 h decreased bacterial adhesion in 75% of the samples compared to incubation in buffer. Thus, the contribution of CSF proteins, like fibronectin, for the initial bacterial adhesion might be small. Heparinization of silicone and PVC decreased the numbers of adhered bacteria by 23 to 54% and 0 to 43% compared to unheparinized surfaces. Among putative inhibitors tested, suramin, chondroitin sulfate, and fucoidan inhibited adhesion to 81 +/- 19, 78 +/- 22, and 64 +/- 7%, respectively. These findings indicate that hydrophobic interactions play an important role, and heparinization rendering the biomaterial surface hydrophilic is therefore effective to reduce bacterial adhesion. Heparinized polymers incubated with putative inhibitors may be the optimal way to prevent shunt infections.