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

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  • 1 Health Services Consulting Corporation, Boxborough;
  • | 2 Market Access, DePuy Synthes;
  • | 3 US Commercial Marketing, Codman Neurosurgery, Codman Neuro, DePuy Synthes, Raynham, Massachusetts; and
  • | 4 Department of Neurosurgery, Vanderbilt University, Nashville, Tennessee
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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.

ABBREVIATIONS

AIC = antibiotic-impregnated catheter; EVD = external ventricular drain; RCT = randomized controlled trial.

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.

ABBREVIATIONS

AIC = antibiotic-impregnated catheter; EVD = external ventricular drain; RCT = randomized controlled trial.

Hydrocephalus is the pathological accumulation of CSF in the cerebral ventricles and is caused by a variety of factors such as intrauterine infection, meningitis, hemorrhage, and tumors.16 Surgical insertion of a catheter to reduce and control intracranial pressure is the standard treatment for hydrocephalus. Surgery for CSF catheter placement or revision is associated with a risk of complications due primarily to mechanical issues and infection. Other possible adverse events include intraabdominal complications, intracerebral hemorrhage, and perioperative epilepsy. Infection from bacterial contamination can lead to shunt failure and serious complications, including reduced intelligence quotient and psychomotor retardation in children and meningitis, endocarditis, and prolonged hospitalization in adults.36

Despite multiple preventive strategies for reducing infection, up to 15% of patients with shunt catheters34 and up to 27% of patients with external ventricular drains (EVDs) may develop an infection.37 These patients face twice the risk of mortality5 and 3 times the number of shunt-related operations.30 The average cost of a CSF catheter–related infection in the US is estimated to be approximately $50,000.3,11,20,25 Even when infections are successfully treated, long-term morbidities, including seizures, cognitive deficits, and psychomotor retardation, can develop.35

Mounting evidence suggests that the use of antimicrobial-impregnated shunt and EVD catheters may help minimize infection rates in hydrocephalus treatment. Antimicrobial impregnated catheter silicone material is impregnated with the antibiotics rifampin and clindamycin (BACTISEAL, DePuy Synthes). These antibiotics release slowly and uniformly from the exterior and interior lumen surfaces of the catheter, reducing gram-positive bacterial colonization for up to 50 days.4 The very low infection rate associated with such catheters in rigorously controlled clinical trials has been shown to translate to routine clinical practice.31

In the current climate of tighter budgets and stricter management guidelines, it is important for hospitals to assess both the clinical and economic value of medical technologies. Conducting cost-effectiveness analyses helps hospital decision makers to make the proper tradeoffs in a period of financial constraints and need for optimal resource allocation.6 There are few data on the cost-effectiveness of measures to prevent hydrocephalus catheter infection from the hospital perspective; thus, further high-quality cost-effectiveness assessment is needed to facilitate this decision-making process.

In 2011, Klimo et al.19 conducted a meta-analysis assessing the extent to which antibiotic-impregnated catheter (AIC) shunts reduced the rate of infection compared with standard shunts and estimated the degree to which AIC shunts could decrease infection-related hospital expenses on a national level. The objective of the current analysis was to perform a broader cost-consequence analysis of the use of AIC shunts as well as AIC EVDs compared with non-AIC shunts and EVDs from a hospital perspective using recently published clinical data and cost inputs. Outcomes evaluated include infections, deaths due to infection, surgeries due to infection, and costs associated with shunt- and EVD-related infection.

Methods

Overall Approach

Decision analytical modeling was the approach used in this cost-consequence evaluation. A decision analytical model is a structured representation of real-world health care activities and is used to predict the clinical and economic outcomes that are expected to result with adoption of an intervention. Decision analytical models bring together knowledge from a variety of sources (such as clinical trials, databases, and costs) when adequate experimental and/or long-term data are not available. A decision analysis involves selecting appropriate comparators, creating a decision tree structure modeling the clinical pathways, determining what payoffs or clinical and economic outputs to assess, populating the model with appropriate clinical and economic inputs (event probabilities, resource utilization, and costs), and running the analysis.

Target Audience, Perspective, Comparators, and Outcomes Evaluated

The target audience is US health care decision makers in the hospital setting; thus, a hospital perspective was adopted for this analysis. The time horizon (the analytical horizon that would adequately capture relevant outcomes) was set at 18 months, based on the length of follow-up for the studies evaluating the burden of catheter infection. Clinical outcomes considered included infections, deaths, and surgeries. Only the costs of catheters and infections were included in the economic analysis because these were the only outcomes where differences in costs were expected between AICs and non-AICs. The target patient population includes all inpatients requiring shunt and EVD catheters. The comparators in the evaluation were AIC versus non-AIC shunts and AIC versus non- AIC EVDs. Five separate outcomes were evaluated and compared between treatment arms: number of infections, number of deaths due to infection, number of days of hospitalization due to infection, number of surgeries due to infection, and cost of infection.

Data Sources for Populating the Model

The clinical and economic data used to populate the decision analytical model were obtained from the published literature. A search of peer-reviewed literature was conducted using the MEDLINE (PubMed) database. Clinical studies comparing infection rates and the economic impact associated with the use of AICs and standard non-AICs were evaluated. The results of the analyses were presented separately for shunt and EVD catheters.

Clinical Inputs

A published meta-analysis by Parker et al.22 was used as the foundation of clinical evidence for shunt catheters. A search for studies published since May 2010 (the end search date of the meta-analysis) was performed using the same search terms used by Parker et al. [(“shunt” OR “hydrocephalus”) AND (“infection” OR “antibiotic-impregnated” OR “AIS” (antibiotic-impregnated shunt OR “Bactiseal”)] to update the search. Reference lists of identified articles were reviewed to capture any additional studies that may not have been identified from the search. Only studies that defined shunt infection as a clinically symptomatic event with confirmatory laboratory data were included, per Parker et al.22 Cumulative results from the studies (rates for AIC and non-AIC shunts weighted by the number of patients in the arms of each of the studies) were used as weighted average inputs for the model.

A literature search similar to the shunt catheter meta-analysis search was conducted for EVDs. The search term “drain” was substituted for “shunt,” and no date limits were set for the search. As with the shunt literature review, cumulative results from the EVD studies were used as inputs for the model. The study by Gutiérrez-González et al. was the only relevant clinical study that was identified and excluded due to its definition of infection not needing to be a “clinically symptomatic event.”13

Economic Inputs

Costs of shunts, EVDs, and infection were included in the analysis. All costs are presented in US dollars. The cost of AIC shunts or EVDs was estimated from a study by Farber et al.,11 which estimated that the incremental cost of AIC versus non-AIC catheters was $400. Cost of shunt catheter infections was obtained from a pooled estimate of cases evaluated in studies by Attenello et al.3 and Farber et al.11 (pooled estimated cost of shunt infection was $46,394). The cost of an EVD catheter infection was obtained from a single published study by Lyke et al.,20 which estimated it to be $30,335. The study estimates of cost of infection were not inflated to present-day dollars in an effort to be more conservative in assessing the cost savings resulting from AICs.

Cost-Consequence Analysis

A cost-consequence analysis requires an estimation of the costs as well as the health consequences associated with one intervention compared with an alternative intervention for a health condition. The key distinguishing feature of a cost-consequence analysis is the presentation of the results in a simple, disaggregated format. The goal of the cost-consequence analysis is to give the decision maker as broad a view as possible of the consequences of the alternative interventions.

All pertinent clinical and economic information from the articles obtained through the literature review was extracted and summarized. This included the number of catheters in each arm of the study, the study design, the number of infections, the number of deaths due to infection, the number of days of hospitalization due to infection, and the number of surgeries due to infection with AIC and non-AICs.

A rate of infection was calculated for AIC and non-AIC patients in each study, and the relative decrease in infection with AICs was calculated from the 2 rates for each study. The total number of infections was calculated for AICs and non-AICs, and an overall rate of infection for AICs and non-AICs and an overall rate of decrease in infection with AICs were calculated by weighting each study by the number of catheters evaluated. Overall numbers of deaths due to infection, days of hospitalization due to infection, and number of surgeries due to infection were similarly calculated for AICs and non-AICs, and the deaths, hospital days, and surgeries averted with AICs were derived. The costs per infection from the published literature and the incremental cost of an AIC were used to estimate the overall cost per treatment arm and then the net cost savings that might result from use of AICs.

Subanalysis

The majority of the studies evaluating AICs are observational. According to the Center for Evidence-Based Medicine, Level I evidence requires prospective, randomized, controlled, blinded trials with clearly defined primary outcomes and inclusion/exclusion criteria.7 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.

Sensitivity and Threshold Analyses

Because the model contained a number of assumptions, it was necessary to conduct sensitivity analyses to determine how changes in the values of uncertain parameters affected the results of the model. The following clinical parameters were tested to measure the robustness of the model and to determine the importance of the individual parameters in model results: percent decrease in rate of infection with AIC shunt and EVD catheters, incremental cost of AIC shunt and EVDs, and cost of a shunt and EVD infections.

The sensitivity analyses were presented as tornado diagrams to illustrate the relative impact of the various model inputs. Threshold analyses were also conducted to determine the value of the above variables at which the impact of non-AICs was cost neutral (i.e., the value at which the cost savings due to averted infections was equal to the incremental cost of using AIC catheters).

Results

Shunt Catheters

Fourteen studies evaluating AIC versus non-AIC shunts in the treatment of hydrocephalus were identified. Thirteen of the studies were observational (9 retrospective and 4 prospective) and did not adjust for confounders, and one study was a randomized controlled trial (RCT). Across the uncontrolled observational studies, demographics, etiology of hydrocephalus, and type of shunt surgery were similar between groups of patients treated with AIC and standard non-AIC shunts. Aggregated results showed an overall decrease in infection of 50.3% with the use of AIC shunt catheters. All shunt studies compared BACTISEAL shunt catheters to standard non-AICs. Table 1 presents the findings of the literature review for studies evaluating pediatric patients, adult patients, and pediatric and adult patients combined.

TABLE 1

Summary of studies comparing AIC versus standard non-AIC shunts

Authors & YearNo. of ShuntsStudy DesignNo. of InfectionsRate of InfectionDecrease Infection w/AIC Shunt
AIC ShuntNon-AIC ShuntAIC ShuntNon-AIC ShuntAIC ShuntNon-AIC Shunt
Adult series
 Albanese et al., 2009612Retrospective cohort070.0%58.3%100.0%
 Eymann et al., 200817198Retrospective cohort140.6%4.1%85.7%
 Farber et al., 2011250250Retrospective cohort3101.2%4.0%70.0%
 Subtotal/weighted average4273604210.9%5.8%83.9%
Pediatric series
 Aryan et al., 20053246Retrospective cohort173.1%15.2%79.5%
 Eymann et al., 20082622Retrospective cohort133.8%13.6%71.8%
 Hayhurst et al., 200821477Retrospective cohort2189.8%10.4%5.5%
 Kan & Kestle, 20078080Retrospective cohort475.0%8.8%42.9%
 Parker et al., 2009502570Retrospective cohort16643.2%11.2%71.6%
 Kandasamy et al., 20115811963Prospective cohort/retrospective control301555.2%7.9%34.6%
 Subtotal/weighted average14352758732445.1%8.8%42.5%
Combined adult & pediatric series
 Govender et al., 20036075RCT3105.0%13.3%62.5%
 Pattavilakom et al., 2007243551Prospective cohort/retrospective control3361.2%6.5%81.1%
 Richards et al., 2009994994Retrospective cohort30473.0%4.7%36.2%
 Ritz et al., 200786172Prospective cohort/retrospective control5105.8%5.8%0.0%
 Steinbok et al., 201046387Prospective cohort0140.0%3.6%100.0%
 Subtotal/weighted average14292179411172.9%5.4%46.6%
Total/weighted average329152971183823.6%7.2%50.3%

Twelve of 14 studies of AIC shunts demonstrated a decrease in infection rates. Only 2 of 14 AIC shunt studies did not show a significant decrease in the rate of infection with use of AICs. A greater decrease in the rate of infection was seen with adult patients compared with pediatric patients (83.9% vs 42.5% for pediatric patients).

Five of the studies evaluating shunts also reported rates of mortality due to infection for AIC and non-AIC shunts,1,9,12,24,28 and 2 studies reported the number of hospital days and the number of surgeries from infection for AIC and non-AIC shunts.3,11 Overall rates of mortality, days of hospitalization, and number of surgeries were calculated by weighting these studies' rates by the number of shunts evaluated, and then multiplying these weighted rates by the rate of infection for AIC and non-AIC shunts.

Figure 1 depicts the clinical and economic consequences and the net effects that may be associated with the use of non-AIC or AIC shunts in 100 patients requiring shunts for hydrocephalus. Results of the modeling evaluation estimated that 7.2 infections would be experienced per 100 patients with non-AICs. This number would be halved if AICs were used instead of non-AICs in the 100 patients. The clinical consequences of these fewer infections would be lower mortality (0.5 deaths averted), decreases in infection-related hospital days (71 hospital days averted), decreases in surgeries (11 surgeries averted), and decreases in cost with the use of AIC shunts instead of non-AIC shunts ($128,228 saved per 100 patients treated with AICs).

FIG. 1.
FIG. 1.

Clinical and economic impact of 100 AIC shunts versus 100 non-AIC shunts. Figure is available in color online only.

A subanalysis using Level I evidence for shunts was performed using only the data from Govender et al.12 The infection rates seen in this RCT were higher than the infection rates seen in the observational shunt AIC studies. This may be due to enhanced monitoring for infection that may occur with an RCT. The relative rate of infection between AIC and non-AIC groups in this study was very similar to the relative rate of infection seen with the observational trials. Results of the subanalysis showed that 13.3 infections would be experienced per 100 patients with non- AIC shunts and 5.0 infections would be experienced per 100 patients with AIC shunts (8.3 infections averted per 100 patients with AIC shunts). The clinical consequences of these fewer infections would be 1.9 infection-related deaths averted, 161 infection-related hospital days averted, 25 infection-related surgeries averted, and $346,616 saved per 100 patients treated with AIC shunts.

Sensitivity Analyses

The proportion of decrease in infection with AIC shunt was varied ± 75% based on the significant range of values seen in the literature review. A sensitivity analysis on the baseline infection rate or number of infections would look identical to the sensitivity analysis on the rate of decrease in infection with the AIC because these 2 variables are multiplied together to obtain the number of infections, and therefore varying either produces the same result. The costs of shunt infection presented in the published literature typically were presented as charges and showed significant variability, so a range of ± 50% was presented in sensitivity analyses. The cost of the AIC shunts was also varied ± 75% in sensitivity analyses to determine the potential impact of this range of cost. Figure 2 presents a tornado diagram illustrating the relative impact of varying the parameter values selected for sensitivity analysis.

FIG. 2.
FIG. 2.

One-way sensitivity analysis results for the non-AIC versus AIC shunt model. Base case savings of $128,228 with AIC shunts are shown by the point between the red and blue bars. Sensitivity analysis blue bars indicate the range of higher potential savings and red bars indicate the range of lower potential savings. Figure is available in color online only.

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. Varying the cost of shunt infection also had a significant impact on model results. The cost of AIC shunts had the smallest impact on net cost savings seen with AIC shunts. Threshold analyses determined the value at which cost savings from averted infection were equal to the incremental cost of using AICs. The thresholds at which AIC shunts were cost neutral occurred when the percent decrease in infection was set at 12.0%, when the cost of shunt infection was set at $11,031, or when the incremental cost of AIC shunts was set at $1682 per device.

External Ventricular Drains

Six studies evaluating AIC versus non-AIC EVDs in the treatment of hydrocephalus were identified. Two of the 6 studies were RCTs in adults, 2 were prospective cohort studies in children, and 2 were prospective cohort studies in pediatric and adult patients combined. As was seen with shunt catheters, patients in the 2 treatment groups of the EVD studies were similar in terms of demographics, etiology of hydrocephalus, and the type of EVD surgery. All EVD studies except the study in adults by Zabramski et al.37 compared BACTISEAL EVD catheters to standard non-AICs. Aggregated results for EVDs also showed a decrease in the rate of infection (overall total decrease of 75.2%) (Table 2).

TABLE 2

Summary of studies comparing AIC versus standard non-AIC EVDs

Authors & YearNo. of DrainsStudy DesignNo. of InfectionsRate of InfectionDecrease Infection w/AIC EVD
AIC EVDNon-AIC EVDAIC EVDNon-AIC EVDAIC EVDNon-AIC EVD
Adult series
 Zabramski et al., 2003149139RCT2131.3%9.4%85.6%
 Pople et al., 2012176181RCT452.3%2.8%17.7%
 Subtotal/weighted average3253206181.8%5.6%67.2%
Pediatric series
 Tamburrini et al., 20084744Prospective cohort1142.1%31.8%93.3%
 Rivero-Garviá et al., 2011248400Prospective cohort6682.4%17.0%85.8%
 Subtotal/weighted average2954447822.4%18.5%87.2%
Combined adult & pediatric series
 Harrop et al., 2010195608Prospective cohort2451.0%7.4%86.1%
 Muttaiyah et al., 20106060Prospective cohort/retrospective control144623.3%76.7%69.6%
 Subtotal/weighted average25566816916.3%13.6%53.9%
Total/weighted average8751432291913.3%13.3%75.2%

Although there were fewer published studies available for AIC EVDs, the AIC EVD studies consistently showed a decrease in the rate of infection with the use of AICs. In the case of EVDs, a greater decrease in the rate of infection was seen with pediatric patients compared with adult patients (87.2% vs 67.2% for adult patients).

The study by Lyke et al.20 reported rates of mortality due to infection and the number of hospital days from infection for AIC and non-AIC EVDs. The study also evaluated the risk of more severe neurological impairment resulting from infection. The reduction in infection seen with antimicrobial-impregnated catheter EVDs translated into improvements in mortality and morbidity, and reduced hospital costs associated with infection (Fig. 3).

FIG. 3.
FIG. 3.

Clinical and economic impact of 100 AIC EVDs versus 100 non-AIC EVDs. Figure is available in color online only.

In 100 patients requiring EVD catheters, the use of AICs may be associated with 2.7 fewer infection-related deaths and 82 fewer hospital days due to infection. The relative risk of more severe neurological impairment occurring at discharge or in the hospital was estimated to be 5.33 after an EVD infection. Decreases in infection with AIC EVDs resulted in an estimated $264,069 of savings per 100 patients treated with AICs.

A subanalysis using Level I evidence for EVDs was performed using only the combined data from Zabramski et al.37 and Pople et al.26 Results of this subanalysis showed that 5.6 infections would be experienced per 100 patients with non-AIC EVDs and 1.8 infections would be experienced per 100 patients with AIC EVDs (3.8 infections averted per 100 patients with AIC EVDs). The clinical consequences of these fewer infections would be 1.0 infection-related deaths averted, 31 infection-related hospital days averted, and $74,631 saved per 100 patients treated with AIC EVDs.

Sensitivity Analyses

The sensitivity analyses of the 3 variables varied in the EVD model are presented as a tornado diagram in Fig. 4. 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. Varying the cost of EVD infection again also had a significant impact on model results. The cost of AIC EVDs had the smallest impact on net cost savings seen with AIC EVDs. The thresholds at which AIC EVDs were cost neutral occurred when the percent decrease in infection with EVD was set at 9.9%, when the cost of EVD infection was set at $3991, or when the incremental cost of AIC EVDs was set at $3041 per device.

FIG. 4.
FIG. 4.

One-way sensitivity analysis results for the non-AIC versus AIC EVD model. Base case savings of $264,069 with AIC EVDs are shown by the point between the red and blue bars. Sensitivity analysis blue bars indicate the range of higher potential savings, and red bars indicate the range of lower potential savings. Figure is available in color online only.

Discussion

Findings in the Context of Our Current Health Care Delivery Environment

The challenge to both payers and providers of health care is to maximize the net benefit obtained from health care expenditures. The rising costs of health care delivery pose significant concerns to system viability; thus, improving outcomes while restricting costs is a primary concern of reform efforts around the world. For example, the National Health Service Payment by Results Guidance for 2013–2014 specifies that hospitals will not receive payment for some emergency readmissions within 30 days of discharge following an elective admission.8

The current value analysis demonstrates that evidence supports the use of AIC shunts and EVDs as effective and cost-saving treatment strategies. The use of AICs is expected to reduce the number of CSF catheter infections, save lives, decrease hospital days, decrease the number of surgeries required, reduce the incidence and extent of neurological impairment, and reduce overall hospital costs.

This study differs from the 4 other published cost analyses of AICs.3,9,12,19 First of all, this is the only evaluation that assessed both AIC shunts and AIC EVDs; all others only evaluated AIC shunts. Also, this is the only evaluation that attempted to present more comprehensive clinical consequences of AIC shunts and EVDs; outcomes assessed included infections, deaths from infection, and surgeries due to infection. Three of the previously published AIC cost analyses used data from a single institution to estimate the incidence of shunt infection and the economic impact of AICs,3,9,11 whereas the current evaluation combined results from all available clinical studies of AICs versus non-AICs. Klimo et al.19 also used meta-analytical techniques to summarize data for AIC shunts. The current study differs from that by Klimo et al.19 because it used alternate meta-analytical techniques and different criteria for study inclusion (required that infections be clinically symptomatic events) and assessed a range of clinical consequences for AICs, and included an analysis of EVD AICs as well as AIC shunts.

Robustness of the Findings

Twelve of 14 studies of AIC shunts demonstrated a significant decrease in infection rates. Only 2 of 14 AIC shunt studies did not show a decrease in the rate of infection with use of AICs. In the case of Hayhurst et al., more than a quarter of patients with AICs were patients with an especially higher risk for infection due to previous shunt infection, meningitis, EVD-associated ventriculitis, or conversion of an EVD to an indwelling shunt.15 In the other study by Ritz et al., 3 of the 5 infections in the AIC cohort were the result of skin ulceration or neurosurgical procedures with CSF leakage after shunt implantation.28 Although there are fewer published studies available for AIC EVDs, the AIC EVD studies consistently showed a substantial decrease in the rate of infection with the use of AICs. A greater decrease in the rate of infection was seen with adult patients compared with pediatric patients.

Results from models are only as credible as the inputs that populate them; therefore, we conducted subanalyses that included data from only Level I studies. Although the subanalyses for both shunts and EVDs resulted in lower effect sizes, they confirmed the overall results of the decision analysis models that AICs are associated with lower infection rates and cost savings. Sensitivity analysis re- sults showed that the economic model was most sensitive to the rate of decrease in infection with non-AICs. Cost analyses are inherently proprietary, and published models may provide a starting point for appraising the value of alternate therapies.

Limitations

There are some limitations associated with this analysis. Most of the available evidence comes from nonrandomized studies. Comparisons of baseline characteristics indicated that patients in the AIC and non-AIC groups were similar; however, it is possible that results are confounded, and observed differences between groups are due to other variables. Also, some of the presented data came from studies with numerical trends, not statistically significant results, and not all of the studies contained information on all outcomes (i.e., length of hospital stay, infections, repeat surgeries, morbidity, and mortality). Furthermore, data from retrospective databases may not have been originally collected for the specific research purposes and therefore may be incomplete or have errors.

Simplifying assumptions are required in decision analytical models. Achieving a balance between determining reasonable clinical treatment pathways and creating a transparent model based on published evidence is the desired outcome. The model was built by combining data from multiple sources to identify inputs for effectiveness, resource utilization, and costs. Lack of homogeneity of data sources is a common critique of economic evaluations based on modeling techniques. Data obtained from a retrospective claims analysis might have provided a more homogenous representation of actual costs and utilization; however, properly adjusting for covariates in administrative claims analyses is also difficult, and the populations of a specific database may not be representative of all patients requiring catheters. A prospective, randomized cost-effectiveness evaluation would be another approach to collecting economic evidence first hand.

In terms of the clinical and economic consequences of infection, resource use and cost estimates were mostly derived from studies conducted at a single US site (The Johns Hopkins Hospital) and are not necessarily representative of all settings of care or other countries. Costs presented in the analysis are based on hospital charges (the only published cost data available), which may overestimate actual costs. Nonhospital medical costs and indirect costs such as missed work and lost productivity were not assessed in this study.

Conclusions

This cost-consequence analysis assessed the value of AIC shunts and EVDs compared with non-AIC shunts and EVDs in the treatment of hydrocephalus from a hospital perspective. The analysis demonstrated that the evidence supports the use of shunt and EVD AICs as effective and potentially cost-saving treatment strategies. The use of shunt and EVD AICs may be associated with a decrease in the number of infections, fewer deaths from infection, fewer surgeries due to infection, and lower costs associated with shunt and EVD-related infection.

Author Contributions

Conception and design: all authors. Acquisition of data: all authors. Analysis and interpretation of data: all authors. Drafting the article: Edwards, Engelhart, Casamento. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Edwards.

Supplemental Information

Current Affiliation

Dr. McGirt: Neurosurgery & Spine Associates and University of North Carolina, Charlotte, NC.

References

  • 1

    Albanese A, , De Bonis P, , Sabatino G, , Capone G, , Marchese E, & Vignati A, et al.: Antibiotic-impregnated ventriculo-peritoneal shunts in patients at high risk of infection. Acta Neurochir (Wien) 151:12591263, 2009

    • Search Google Scholar
    • Export Citation
  • 2

    Aryan HE, , Meltzer HS, , Park MS, , Bennett RL, , Jandial R, & Levy ML: Initial experience with antibiotic-impregnated silicone catheters for shunting of cerebrospinal fluid in children. Childs Nerv Syst 21:5661, 2005

    • Search Google Scholar
    • Export Citation
  • 3

    Attenello FJ, , Garces-Ambrossi GL, , Zaidi HA, , Sciubba DM, & Jallo GI: Hospital costs associated with shunt infections in patients receiving antibiotic-impregnated shunt catheters versus standard shunt catheters. Neurosurgery 66:284289, 2010

    • Search Google Scholar
    • Export Citation
  • 4

    Bayston R, & Lambert E: Duration of protective activity of cerebrospinal fluid shunt catheters impregnated with antimicrobial agents to prevent bacterial catheter-related infection. J Neurosurg 87:247251, 1997

    • Search Google Scholar
    • Export Citation
  • 5

    Blount JP, & Haines SJ, Infections of cerebrospinal shunts. Youmans JR: Neurological Surgery ed 4 Philadelphia, WB Saunders, 1996. 945966

    • Search Google Scholar
    • Export Citation
  • 6

    Brauer CA, , Neumann PJ, & Rosen AB: Trends in cost effectiveness analyses in orthopaedic surgery. Clin Orthop Relat Res 457:4248, 2007

  • 7

    Center for Evidence-Based Medicine: Oxford Centre for Evidence-based Medicine–Levels of Evidence (March 2009) (http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009/) [Accessed September 26, 2014]

    • Search Google Scholar
    • Export Citation
  • 8

    Department of Health Payment by Results Team: Payment by Results Guidance for 2013–2014 Leeds, UK, National Health Service, 2013. (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/214902/PbR-Guidance-2013-14.pdf) [Accessed September 26, 2014]

    • Search Google Scholar
    • Export Citation
  • 9

    Eymann R, , Chehab S, , Strowitzki M, , Steudel WI, & Kiefer M: Clinical and economic consequences of antibiotic-impregnated cerebrospinal fluid shunt catheters. J Neurosurg Pediatr 1:444450, 2008

    • Search Google Scholar
    • Export Citation
  • 10

    Farber SH, , Parker SL, , Adogwa O, , McGirt MJ, & Rigamonti D: Effect of antibiotic-impregnated shunts on infection rate in adult hydrocephalus: a single institution's experience. Neurosurgery 69:625629, 2011

    • Search Google Scholar
    • Export Citation
  • 11

    Farber SH, , Parker SL, , Adogwa O, , Rigamonti D, & McGirt MJ: Cost analysis of antibiotic-impregnated catheters in the treatment of hydrocephalus in adult patients. World Neurosurg 74:528531, 2010

    • Search Google Scholar
    • Export Citation
  • 12

    Govender ST, , Nathoo N, & van Dellen JR: Evaluation of an antibiotic-impregnated shunt system for the treatment of hydrocephalus. J Neurosurg 99:831839, 2003

    • Search Google Scholar
    • Export Citation
  • 13

    Gutiérrez-González R, , Boto GR, , Fernández-Pérez C, & del Prado N: Protective effect of rifampicin and clindamycin impregnated devices against Staphylococcus spp. infection after cerebrospinal fluid diversion procedures. BMC Neurol 10:93, 2010

    • Search Google Scholar
    • Export Citation
  • 14

    Harrop JS, , Sharan AD, , Ratliff J, , Prasad S, , Jabbour P, & Evans JJ, et al.: Impact of a standardized protocol and antibiotic-impregnated catheters on ventriculostomy infection rates in cerebrovascular patients. Neurosurgery 67:187191, 2010

    • Search Google Scholar
    • Export Citation
  • 15

    Hayhurst C, , Cooke R, , Williams D, , Kandasamy J, , O'Brien DF, & Mallucci CL: The impact of antibiotic-impregnated catheters on shunt infection in children and neonates. Childs Nerv Syst 24:557562, 2008

    • Search Google Scholar
    • Export Citation
  • 16

    Jansen J: Etiology and prognosis in hydrocephalus. Childs Nerv Syst 4:263267, 1988

  • 17

    Kan P, & Kestle J: Lack of efficacy of antibiotic-impregnated shunt systems in preventing shunt infections in children. Childs Nerv Syst 23:773777, 2007

    • Search Google Scholar
    • Export Citation
  • 18

    Kandasamy J, , Dwan K, , Hartley JC, , Jenkinson MD, , Hayhurst C, & Gatscher S, et al.: Antibiotic-impregnated ventriculoperitoneal shunts—a multi-centre British paediatric neurosurgery group (BPNG) study using historical controls. Childs Nerv Syst 27:575581, 2011

    • Search Google Scholar
    • Export Citation
  • 19

    Klimo P Jr, , Thompson CJ, , Ragel BT, & Boop FA: Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis. Clinical article. J Neurosurg Pediatr 8:600612, 2011

    • Search Google Scholar
    • Export Citation
  • 20

    Lyke KE, , Obasanjo OO, , Williams MA, , O'Brien M, , Chotani R, & Perl TM: Ventriculitis complicating use of intraventricular catheters in adult neurosurgical patients. Clin Infect Dis 33:20282033, 2001

    • Search Google Scholar
    • Export Citation
  • 21

    Muttaiyah S, , Ritchie S, , John S, , Mee E, & Roberts S: Efficacy of antibiotic-impregnated external ventricular drain catheters. J Clin Neurosci 17:296298, 2010

    • Search Google Scholar
    • Export Citation
  • 22

    Parker SL, , Anderson WN, , Lilienfeld S, , Megerian JT, & McGirt MJ: Cerebrospinal shunt infection in patients receiving antibiotic-impregnated versus standard shunts. A review. J Neurosurg Pediatr 8:259265, 2011

    • Search Google Scholar
    • Export Citation
  • 23

    Parker SL, , Attenello FJ, , Sciubba DM, , Garces-Ambrossi GL, , Ahn E, & Weingart J, et al.: Comparison of shunt infection incidence in high-risk subgroups receiving antibiotic-impregnated versus standard shunts. Childs Nerv Syst 25:7785, 2009

    • Search Google Scholar
    • Export Citation
  • 24

    Pattavilakom A, , Xenos C, , Bradfield O, & Danks RA: Reduction in shunt infection using antibiotic impregnated CSF shunt catheters: an Australian prospective study. J Clin Neurosci 14:526531, 2007

    • Search Google Scholar
    • Export Citation
  • 25

    Patwardhan RV, & Nanda A: Implanted ventricular shunts in the United States: the billion-dollar-a-year cost of hydrocephalus treatment. Neurosurgery 56:139145, 2005

    • Search Google Scholar
    • Export Citation
  • 26

    Pople I, , Poon W, , Assaker R, , Mathieu D, , Iantosca M, & Wang E, et al.: Comparison of infection rate with the use of antibiotic-impregnated vs standard extraventricular drainage devices: a prospective, randomized controlled trial. Neurosurgery 71:613, 2012

    • Search Google Scholar
    • Export Citation
  • 27

    Richards HK, , Seeley HM, & Pickard JD: Efficacy of antibiotic-impregnated shunt catheters in reducing shunt infection: data from the United Kingdom Shunt Registry. Clinical article. J Neurosurg Pediatr 4:389393, 2009

    • Search Google Scholar
    • Export Citation
  • 28

    Ritz R, , Roser F, , Morgalla M, , Dietz K, , Tatagiba M, & Will BE: Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients. BMC Infect Dis 7:38, 2007

    • Search Google Scholar
    • Export Citation
  • 29

    Rivero-Garvía M, , Márquez-Rivas J, , Jiménez-Mejías ME, , Neth O, & Rueda-Torres AB: Reduction in external ventricular drain infection rate. Impact of a minimal handling protocol and antibiotic-impregnated catheters. Acta Neurochir (Wien) 153:647651, 2011

    • Search Google Scholar
    • Export Citation
  • 30

    Schoenbaum SC, , Gardner P, & Shillito J: Infections of cerebrospinal fluid shunts: epidemiology, clinical manifestations, and therapy. J Infect Dis 131:543552, 1975

    • Search Google Scholar
    • Export Citation
  • 31

    Sloffer CA, , Augspurger L, , Wagenbach A, & Lanzino G: Antimicrobial-impregnated external ventricular catheters: does the very low infection rate observed in clinical trials apply to daily clinical practice?. Neurosurgery 56:10411044, 2005

    • Search Google Scholar
    • Export Citation
  • 32

    Steinbok P, , Milner R, , Agrawal D, , Farace E, , Leung GK, & Ng I, et al.: A multicenter multinational registry for assessing ventriculoperitoneal shunt infections for hydrocephalus. Neurosurgery 67:13031310, 2010

    • Search Google Scholar
    • Export Citation
  • 33

    Tamburrini G, , Massimi L, , Caldarelli M, & Di Rocco C: Antibiotic impregnated external ventricular drainage and third ventriculostomy in the management of hydrocephalus associated with posterior cranial fossa tumours. Acta Neurochir (Wien) 150:10491056, 2008

    • Search Google Scholar
    • Export Citation
  • 34

    Tunkel AR, & Drake JM, Cerebrospinal fluid shunt infections. Mandell GL, , Bennett JE, & Dolin R: Principles and Practice of Infectious Diseases ed 7 Philadelphia, Churchill Livingstone Elsevier, 2010. 12311236

    • Search Google Scholar
    • Export Citation
  • 35

    Vinchon M, & Dhellemmes P: The transition from child to adult in neurosurgery. Adv Tech Stand Neurosurg 32:324, 2007

  • 36

    Wu Y, , Green NL, , Wrensch MR, , Zhao S, & Gupta N: Ventriculoperitoneal shunt complications in California: 1990 to 2000. Neurosurgery 61:557563, 2007

    • Search Google Scholar
    • Export Citation
  • 37

    Zabramski JM, , Whiting D, , Darouiche RO, , Horner TG, , Olson J, & Robertson C, et al.: Efficacy of antimicrobial-impregnated external ventricular drain catheters: a prospective, randomized, controlled trial. J Neurosurg 98:725730, 2003

    • Search Google Scholar
    • Export Citation
  • View in gallery

    Clinical and economic impact of 100 AIC shunts versus 100 non-AIC shunts. Figure is available in color online only.

  • View in gallery

    One-way sensitivity analysis results for the non-AIC versus AIC shunt model. Base case savings of $128,228 with AIC shunts are shown by the point between the red and blue bars. Sensitivity analysis blue bars indicate the range of higher potential savings and red bars indicate the range of lower potential savings. Figure is available in color online only.

  • View in gallery

    Clinical and economic impact of 100 AIC EVDs versus 100 non-AIC EVDs. Figure is available in color online only.

  • View in gallery

    One-way sensitivity analysis results for the non-AIC versus AIC EVD model. Base case savings of $264,069 with AIC EVDs are shown by the point between the red and blue bars. Sensitivity analysis blue bars indicate the range of higher potential savings, and red bars indicate the range of lower potential savings. Figure is available in color online only.

  • 1

    Albanese A, , De Bonis P, , Sabatino G, , Capone G, , Marchese E, & Vignati A, et al.: Antibiotic-impregnated ventriculo-peritoneal shunts in patients at high risk of infection. Acta Neurochir (Wien) 151:12591263, 2009

    • Search Google Scholar
    • Export Citation
  • 2

    Aryan HE, , Meltzer HS, , Park MS, , Bennett RL, , Jandial R, & Levy ML: Initial experience with antibiotic-impregnated silicone catheters for shunting of cerebrospinal fluid in children. Childs Nerv Syst 21:5661, 2005

    • Search Google Scholar
    • Export Citation
  • 3

    Attenello FJ, , Garces-Ambrossi GL, , Zaidi HA, , Sciubba DM, & Jallo GI: Hospital costs associated with shunt infections in patients receiving antibiotic-impregnated shunt catheters versus standard shunt catheters. Neurosurgery 66:284289, 2010

    • Search Google Scholar
    • Export Citation
  • 4

    Bayston R, & Lambert E: Duration of protective activity of cerebrospinal fluid shunt catheters impregnated with antimicrobial agents to prevent bacterial catheter-related infection. J Neurosurg 87:247251, 1997

    • Search Google Scholar
    • Export Citation
  • 5

    Blount JP, & Haines SJ, Infections of cerebrospinal shunts. Youmans JR: Neurological Surgery ed 4 Philadelphia, WB Saunders, 1996. 945966

    • Search Google Scholar
    • Export Citation
  • 6

    Brauer CA, , Neumann PJ, & Rosen AB: Trends in cost effectiveness analyses in orthopaedic surgery. Clin Orthop Relat Res 457:4248, 2007

  • 7

    Center for Evidence-Based Medicine: Oxford Centre for Evidence-based Medicine–Levels of Evidence (March 2009) (http://www.cebm.net/oxford-centre-evidence-based-medicine-levels-evidence-march-2009/) [Accessed September 26, 2014]

    • Search Google Scholar
    • Export Citation
  • 8

    Department of Health Payment by Results Team: Payment by Results Guidance for 2013–2014 Leeds, UK, National Health Service, 2013. (https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/214902/PbR-Guidance-2013-14.pdf) [Accessed September 26, 2014]

    • Search Google Scholar
    • Export Citation
  • 9

    Eymann R, , Chehab S, , Strowitzki M, , Steudel WI, & Kiefer M: Clinical and economic consequences of antibiotic-impregnated cerebrospinal fluid shunt catheters. J Neurosurg Pediatr 1:444450, 2008

    • Search Google Scholar
    • Export Citation
  • 10

    Farber SH, , Parker SL, , Adogwa O, , McGirt MJ, & Rigamonti D: Effect of antibiotic-impregnated shunts on infection rate in adult hydrocephalus: a single institution's experience. Neurosurgery 69:625629, 2011

    • Search Google Scholar
    • Export Citation
  • 11

    Farber SH, , Parker SL, , Adogwa O, , Rigamonti D, & McGirt MJ: Cost analysis of antibiotic-impregnated catheters in the treatment of hydrocephalus in adult patients. World Neurosurg 74:528531, 2010

    • Search Google Scholar
    • Export Citation
  • 12

    Govender ST, , Nathoo N, & van Dellen JR: Evaluation of an antibiotic-impregnated shunt system for the treatment of hydrocephalus. J Neurosurg 99:831839, 2003

    • Search Google Scholar
    • Export Citation
  • 13

    Gutiérrez-González R, , Boto GR, , Fernández-Pérez C, & del Prado N: Protective effect of rifampicin and clindamycin impregnated devices against Staphylococcus spp. infection after cerebrospinal fluid diversion procedures. BMC Neurol 10:93, 2010

    • Search Google Scholar
    • Export Citation
  • 14

    Harrop JS, , Sharan AD, , Ratliff J, , Prasad S, , Jabbour P, & Evans JJ, et al.: Impact of a standardized protocol and antibiotic-impregnated catheters on ventriculostomy infection rates in cerebrovascular patients. Neurosurgery 67:187191, 2010

    • Search Google Scholar
    • Export Citation
  • 15

    Hayhurst C, , Cooke R, , Williams D, , Kandasamy J, , O'Brien DF, & Mallucci CL: The impact of antibiotic-impregnated catheters on shunt infection in children and neonates. Childs Nerv Syst 24:557562, 2008

    • Search Google Scholar
    • Export Citation
  • 16

    Jansen J: Etiology and prognosis in hydrocephalus. Childs Nerv Syst 4:263267, 1988

  • 17

    Kan P, & Kestle J: Lack of efficacy of antibiotic-impregnated shunt systems in preventing shunt infections in children. Childs Nerv Syst 23:773777, 2007

    • Search Google Scholar
    • Export Citation
  • 18

    Kandasamy J, , Dwan K, , Hartley JC, , Jenkinson MD, , Hayhurst C, & Gatscher S, et al.: Antibiotic-impregnated ventriculoperitoneal shunts—a multi-centre British paediatric neurosurgery group (BPNG) study using historical controls. Childs Nerv Syst 27:575581, 2011

    • Search Google Scholar
    • Export Citation
  • 19

    Klimo P Jr, , Thompson CJ, , Ragel BT, & Boop FA: Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis. Clinical article. J Neurosurg Pediatr 8:600612, 2011

    • Search Google Scholar
    • Export Citation
  • 20

    Lyke KE, , Obasanjo OO, , Williams MA, , O'Brien M, , Chotani R, & Perl TM: Ventriculitis complicating use of intraventricular catheters in adult neurosurgical patients. Clin Infect Dis 33:20282033, 2001

    • Search Google Scholar
    • Export Citation
  • 21

    Muttaiyah S, , Ritchie S, , John S, , Mee E, & Roberts S: Efficacy of antibiotic-impregnated external ventricular drain catheters. J Clin Neurosci 17:296298, 2010

    • Search Google Scholar
    • Export Citation
  • 22

    Parker SL, , Anderson WN, , Lilienfeld S, , Megerian JT, & McGirt MJ: Cerebrospinal shunt infection in patients receiving antibiotic-impregnated versus standard shunts. A review. J Neurosurg Pediatr 8:259265, 2011

    • Search Google Scholar
    • Export Citation
  • 23

    Parker SL, , Attenello FJ, , Sciubba DM, , Garces-Ambrossi GL, , Ahn E, & Weingart J, et al.: Comparison of shunt infection incidence in high-risk subgroups receiving antibiotic-impregnated versus standard shunts. Childs Nerv Syst 25:7785, 2009

    • Search Google Scholar
    • Export Citation
  • 24

    Pattavilakom A, , Xenos C, , Bradfield O, & Danks RA: Reduction in shunt infection using antibiotic impregnated CSF shunt catheters: an Australian prospective study. J Clin Neurosci 14:526531, 2007

    • Search Google Scholar
    • Export Citation
  • 25

    Patwardhan RV, & Nanda A: Implanted ventricular shunts in the United States: the billion-dollar-a-year cost of hydrocephalus treatment. Neurosurgery 56:139145, 2005

    • Search Google Scholar
    • Export Citation
  • 26

    Pople I, , Poon W, , Assaker R, , Mathieu D, , Iantosca M, & Wang E, et al.: Comparison of infection rate with the use of antibiotic-impregnated vs standard extraventricular drainage devices: a prospective, randomized controlled trial. Neurosurgery 71:613, 2012

    • Search Google Scholar
    • Export Citation
  • 27

    Richards HK, , Seeley HM, & Pickard JD: Efficacy of antibiotic-impregnated shunt catheters in reducing shunt infection: data from the United Kingdom Shunt Registry. Clinical article. J Neurosurg Pediatr 4:389393, 2009

    • Search Google Scholar
    • Export Citation
  • 28

    Ritz R, , Roser F, , Morgalla M, , Dietz K, , Tatagiba M, & Will BE: Do antibiotic-impregnated shunts in hydrocephalus therapy reduce the risk of infection? An observational study in 258 patients. BMC Infect Dis 7:38, 2007

    • Search Google Scholar
    • Export Citation
  • 29

    Rivero-Garvía M, , Márquez-Rivas J, , Jiménez-Mejías ME, , Neth O, & Rueda-Torres AB: Reduction in external ventricular drain infection rate. Impact of a minimal handling protocol and antibiotic-impregnated catheters. Acta Neurochir (Wien) 153:647651, 2011

    • Search Google Scholar
    • Export Citation
  • 30

    Schoenbaum SC, , Gardner P, & Shillito J: Infections of cerebrospinal fluid shunts: epidemiology, clinical manifestations, and therapy. J Infect Dis 131:543552, 1975

    • Search Google Scholar
    • Export Citation
  • 31

    Sloffer CA, , Augspurger L, , Wagenbach A, & Lanzino G: Antimicrobial-impregnated external ventricular catheters: does the very low infection rate observed in clinical trials apply to daily clinical practice?. Neurosurgery 56:10411044, 2005

    • Search Google Scholar
    • Export Citation
  • 32

    Steinbok P, , Milner R, , Agrawal D, , Farace E, , Leung GK, & Ng I, et al.: A multicenter multinational registry for assessing ventriculoperitoneal shunt infections for hydrocephalus. Neurosurgery 67:13031310, 2010

    • Search Google Scholar
    • Export Citation
  • 33

    Tamburrini G, , Massimi L, , Caldarelli M, & Di Rocco C: Antibiotic impregnated external ventricular drainage and third ventriculostomy in the management of hydrocephalus associated with posterior cranial fossa tumours. Acta Neurochir (Wien) 150:10491056, 2008

    • Search Google Scholar
    • Export Citation
  • 34

    Tunkel AR, & Drake JM, Cerebrospinal fluid shunt infections. Mandell GL, , Bennett JE, & Dolin R: Principles and Practice of Infectious Diseases ed 7 Philadelphia, Churchill Livingstone Elsevier, 2010. 12311236

    • Search Google Scholar
    • Export Citation
  • 35

    Vinchon M, & Dhellemmes P: The transition from child to adult in neurosurgery. Adv Tech Stand Neurosurg 32:324, 2007

  • 36

    Wu Y, , Green NL, , Wrensch MR, , Zhao S, & Gupta N: Ventriculoperitoneal shunt complications in California: 1990 to 2000. Neurosurgery 61:557563, 2007

    • Search Google Scholar
    • Export Citation
  • 37

    Zabramski JM, , Whiting D, , Darouiche RO, , Horner TG, , Olson J, & Robertson C, et al.: Efficacy of antimicrobial-impregnated external ventricular drain catheters: a prospective, randomized, controlled trial. J Neurosurg 98:725730, 2003

    • Search Google Scholar
    • Export Citation

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