Antibiotic-impregnated Shunt Research Articles

Evaluation of Antibiotic-Impregnated Shunt Catheters in Prevention of Shunt Infections: A Systematic Review

Background: Cerebrospinal fluid (CSF) shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice, with failure rates of 30–40% at 1 year and approximately 50% at 2 years in pediatric patients. Aim of the Work: To study the effectiveness of antimicrobial impregnated catheters in preventing shunt and EVD infections and the impact of antibiotic impregnated catheters on mortality, and prevention colonization. Methods: The PubMed and Scopus databases were searched. Catheter implantation was classified as either shunting (mainly ventriculoperitoneal shunting) or ventricular drainage (mainly external [EVD]). Studies evaluating antibioticimpregnated catheters (AICs), silver-coated catheters (SCCs), and hydrogel-coated catheters (HCCs) were included. A random effects model meta-analysis was performed. Results: Thirty-six studies (7 randomized and 29 nonrandomized, 16,796 procedures) were included. The majority of data derive from studies on the effectiveness of AICs, followed by studies on the effectiveness of SCCs. Statistical heterogeneity was observed in several analyses. Antimicrobial shunt catheters (AICs, SCCs) were associated with lower risk for CSF catheter-associated infections than conventional catheters (CCs) (RR 0.44, 95% CI 0.35-0.56). Fewer infections developed in the patients treated with antimicrobial catheters regardless of randomization, number of participating centers, funding, shunting or ventricular drainage, definition of infections, de novo implantation, and rate of infections in the study. There was no difference regarding gram-positive bacteria, all staphylococci, coagulase-negative streptococci, and Staphylococcus aureus, when analyzed separately. On the contrary, the risk for methicillin-resistant S. aureus (MRSA, RR 2.64, 95% CI 1.26-5.51), nonstaphylococcal (RR 1.75, 95% CI 1.22-2.52), and gram-negative bacterial (RR 2.13, 95% CI 1.33-3.43) infections increased with antimicrobial shunt catheters. Conclusion: The use of antimicrobial shunt catheters reduces the risk for CSF infections in patients with hydrocephalus. Several subgroup analyses showed that factors related to study design, type of catheter, duration of catheter placement, and whether the procedure is a de novo implantation or a revision may affect this risk. Publication bias in the region of small negative trials was also observed.

Intraoperative Injection of Intraventricular Antibiotics is Associated With a Decreased Incidence of Infection and Revision Surgery in Pediatric Hydrocephalus Patients Undergoing Shunt Placement

Abstract INTRODUCTION Infection is the most common cause of morbidity and additional intervention following the placement of a ventriculoperitoneal shunt, even with the use of antibiotic-impregnated catheters. At present, no studies have demonstrated the utility of intraoperative, intraventricular antibiotic injection in reducing the rates of infection and shunt revision. METHODS A prospective, multicenter, shunt-specific neurosurgical registry was used to identify all pediatric patients undergoing first-time placement of a shunt for the definitive treatment of hydrocephalus. All patients who received intraventricular antibiotics (eg, vancomycin or gentamicin) via the shunt catheter during surgery were identified. A variety of variables, including prior temporizing measures (ventriculostomy, subgaleal shunt, reservoir, etc), use of surgical adjuncts (antibiotic-impregnated catheter, stereotactic guidance, choroid plexus coagulation), and reasons for unplanned interventions (infection, CSF leak, catheter obstruction) were collected for each patient. Bivariate statistics and multivariable regression modeling were used to explore the relationship between prophylactic, intraventricular antibiotic placement and subsequent outcomes. RESULTS A total of 2193 pediatric patients undergoing shunt placement for hydrocephalus were identified. Of these, 552 (25.2%) underwent intraoperative injection of antibiotics into the ventricular space. Postoperatively, 104 (4.7%) patients had unplanned removal, replacement, or revision of their shunt at a mean of 14.2 +/− 9 d following the initial procedure. A total of 29 (27.9%) of these interventions were secondary to infection. In a multivariable regression model controlling for patient characteristics, etiology of hydrocephalus, prior temporizing measures, use of image guidance, and placement of an antibiotic-impregnated shunt, intraoperative injection of intraventricular antibiotics was associated with a significant reduction in postoperative infections (OR = 0.217, 95% CI: 0.051–0.916, P = .038). Of those receiving intraventricular antibiotics, only 2 (0.36%) went on to develop an infection. CONCLUSION Pediatric patients who received prophylactic, intraoperative injection of intraventricular antibiotics experienced a significantly decreased incidence of additional surgery secondary to infection, even when controlling for the use of antibiotic-impregnated catheters.

Route of antibiotic prophylaxis for prevention of cerebrospinal fluid-shunt infection.

The main complication of cerebrospinal fluid (CSF) shunt surgery is shunt infection. Prevention of these shunt infections consists of the perioperative use of antibiotics that can be administered in five different ways: orally; intravenously; intrathecally; topically; and via the implantation of antibiotic-impregnated shunt catheters. To determine the effect of different routes of antibiotic prophylaxis (i.e. oral, intravenous, intrathecal, topical and via antibiotic-impregnated shunt catheters) on CSF-shunt infections in persons treated for hydrocephalus using internalised CSF shunts. We conducted a systematic electronic search without restrictions on language, date or publication type. We performed the search on the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE and Embase, with the help of the Information Specialist of the Cochrane Multiple Sclerosis and Rare Diseases of the CNS Group. The search was performed in January 2018. All randomised and quasi-randomised controlled trials that studied the effect of antibiotic prophylaxis, in any dose or administration route, for the prevention of CSF-shunt infection in patients that were treated with an internal cerebrospinal fluid shunt. Patients with external shunts were not eligible. Two review authors independently extracted data from included studies. We resolved disagreements by discussion or by referral to an independent researcher within our department when necessary. Analyses were also performed by at least two authors. We included a total of 11 small randomised controlled trials, containing 1109 participants, in this systematic review. Three of these studies included solely children, and the remaining eight included participants of all ages. Most studies were limited to the evaluation of ventriculoperitoneal shunts. However, five studies included participants with ventriculoatrial shunts, of which one study contained four participants with a subduroperitoneal shunt. We judged four out of 11 (36%) trials at unclear risk of bias, while the remaining seven trials (64%) scored high risk of bias in one or more of the components assessed.We analysed all included studies in order to estimate the effect of antibiotic prophylaxis on the proportion of shunt infections regardless of administration route. Although the quality of evidence in these studies was low, there may be a positive effect of antibiotic prophylaxis on the number of participants who had shunt infections (RR 0.55, 95% CI 0.36 to 0.84), meaning a 55% reduction in the number of participants who had shunt infection compared with standard care or placebo.Within the different administration routes, only within intravenous administration of antibiotic prophylaxis there may be evidence of an effect on the risk of shunt infections (RR 0.55, 95% CI 0.33 to 0.90). However, this was the only route that contained more than two studies (8 studies; 797 participants). Evidence was uncertain for both, intrathecal administration of antibiotics (RR 0.73, 95% CI 0.28 to 1.93, 2 studies; 797 participants; low quality evidence) and antibiotic impregnated catheters (RR 0.36, 95% CI 0.10 to 1.24, 1 study; 110 participants; very low quality evidence) AUTHORS' CONCLUSIONS: Antibiotic prophylaxis may have a positive effect on lowering the number of participants who had shunt infections. However, the quality of included studies was low and the effect is not consistent within the different routes of administration that have been analysed. It is therefore uncertain whether prevention of shunt infection varies by different antibiotic agents, different administration routes, timing and doses; or by characteristics of patients, e.g. children and adults. The results of the review should be seen as hypothesis-generating rather than definitive, and the results should be confirmed in adequately powered trials or large multicentre studies in order to obtain high-quality evidence in the field of ventricular shunt infection prevention.

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/)

Ventriculoperitoneal shunts in neonates: a retrospective study of outcomes with antibiotic-impregnated catheters and a modified peri-operative antibiotic protocol

Background: CSF infection is a significant complication of ventriculoperitoneal (VP) shunts and results in prolonged hospital stay, developmental delay and decreased quality of life. To decrease the high rates of neonatal VP shunt infections, an updated clinical guideline that included the use of antibiotic-impregnated shunts and a revised peri-operative antibiotic protocol was introduced in our neonatal unit. In this study, we evaluated the efficacy of these new guidelines in reducing the CSF shunt infection rates.Methods: A retrospective cohort study of neonates (≤28 days) who had VP shunt insertions in our unit.Results: 24 neonates in the first epoch received plain silastic shunt catheters (Feb 2002–April 2007), and 23 in the second epoch (August 2007–July 2015) received AIS catheters and a revised perioperative antibiotic protocol. Patient demographics were similar between both cohorts. Shunt related CSF infections were reduced in epoch 2 (2/23, 8.7%) compared to epoch 1 (5/24, 20.8%), but the results were not statistically significant (OR 0.36 (0.063–2.090); p = 0.256). Amongst neonates that needed VP shunt revision due to any cause, the median time interval between insertion to revision was significantly later in epoch 2 (epoch 1, 48 days (3–99); epoch 2, 148 days (20–396); p = 0.013).Conclusions: AIS catheters and a 48-hour perioperative antibiotic regimen may be beneficial in neonatal hydrocephalus. Adequately powered RCTs in the neonatal population are needed to confirm these findings.

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

ObjectiveTo investigate infection prevention by antibiotic-impregnated shunts (AIS) relative to conventional ones after pediatric hydrocephalus treatment. MethodsThis single center, retrospective analysis comprised 807 consecutive pediatric cases of hydrocephalus shunting performed by the same neurosurgeon between January 2001 and February 2013. Conventional and AIS catheters were used in 303 and 504 cases, respectively. Study outcomes were infection rates at 6 months (primary), and at 1 month and between 1 and 6 months (secondary). An infant (<1year) subgroup was also analyzed. ResultsThe AIS relative to the conventional catheter group had significantly lower infection rates at 6 months (1.98% [10/504] vs. 5.95% [18/303], two-tailed p=0.0046; central nervous system: 60% and 55.56%; abdominal: 20% and 27.77%; wound: 20% and 16.67%, respectively) and 1 month (0.19% [1/504] vs. 2.65% [8/303], p=0.0023, respectively), but statistically similar rates between 1 and 6 months (1.79% [9/504] vs. 3.30% [10/303], p=0.2296, respectively). In the infant subgroup, AIS application was also associated with reduction in shunt infection (1.49% [7/470] vs. 3.76% [10/266], p=0.0489, respectively). ConclusionAIS as compared to conventional catheter use appears to lower infection risk at 6 months, mainly during the first month, after hydrocephalus therapy in children.

Efficacy of postoperative antibiotic injection in and around ventriculoperitoneal shunt in reduction of shunt infection: A randomized controlled trial

ObjectivesInfection is a common complication of ventriculoperitoneal (VP) shunt surgery. The incidence of shunt infection is still high despite routine administration of perioperative antibiotics. A lower incidence of shunt infection was observed when antibiotic-impregnated shunts (AIS) were used to treat hydrocephalus and a rapid cure was reported in cases of ventriculitis when antibiotics were injected into external ventricular drain (EVD). That is why we theorized that postoperative prophylactic injection of antibiotics in and around the shunt hardware would reduce the incidence of shunt infection. Patients and methodsA randomized controlled clinical trial where 60 patients up to one year old, diagnosed with congenital hydrocephalus and submitted to VP shunt insertion, were randomly assigned to one of 3 groups. The treatment groups received the conventional perioperative antibiotics in addition to vancomycin and gentamicin injection in the reservoir and around the peritoneal catheter either once (group A) or twice (group B), while the control group (C) received only the conventional perioperative antibiotics. Cases were followed-up for up to 1 year. ResultsThe majority of patients were less than 1 month old. The follow-up period ranged from 2 to 12 months with a mean of 8.9 months. The mean duration of onset of infection after surgery was 30 days. Prematurity (p=0.00236), age less than one month (p<0.0001) and duration of surgery of 90min or more (p<0.00001) were significant risk factors for postoperative shunt infection. Significantly more cases of shunt infection occurred within one month after surgery (p=0.021). The control group had significantly more cases of postoperative shunt infection than the treatment groups (p=0.0042). ConclusionsIn congenital hydrocephalus patients submitted to VP shunt insertion, injection of prophylactic vancomycin and gentamicin in and around the shunt hardware significantly reduced the incidence of postoperative shunt infection.

Antibiotic Reservoir Injection Reduces Shunt Infection in Adults

Shunt infections are a major complication following ventricular shunts in adults that lead to increased heath care costs, patient morbidity, and mortality. Methods to decrease shunt infection include antibiotic-impregnated catheters, protocol-based surgery, and shunt reservoir antibiotic injection. An Institutional Review Board-approved retrospective review was performed for all adult shunt surgeries performed from January 2000 to September 2013 at a single academic institution. Records were cross-indexed with hospital billing records to identify patients who received antibiotic injections and cross-referenced with a prospective infection control database of all surgical site infections. The primary outcome measure was shunt infection within 1 year of surgery. Five-hundred thirteen adult patients met inclusion criteria. Antibiotic reservoir injection was associated with a significantly lower rate of infection (2.6%) when compared with no injection (6.3%, P= 0.0455). The antibiotic injection group also included significantly more patients with infection risk factors than the control group (38.8% vs. 18.0%, P < 0.005). Antibiotic reservoir injection is an effective method of reducing shunt infections in adults when combined with standard infection control measures.

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

Cerebrospinal fluid shunt infection is associated with patient morbidity and high cost. We conducted a systematic review of the current evidence of comprehensive surgical protocols or individual interventions designed to reduce shunt infection incidence. A systematic review using PubMed and SCOPUS identified studies evaluating the effect of a particular intervention on shunt infection risk. Systemic prophylactic antibiotic or antibiotic-impregnated shunt efficacy studies were excluded. A total of 7429 articles were screened and 23 articles were included. Eight studies evaluated the effect of comprehensive surgical protocols. Shunt infection was reduced in all studies (absolute risk reduction 2.2-12.3 %). Level of evidence was low (level 4 in seven studies) due to the use of historical controls. Compliance ranged from 24.6 to 74.5 %. Surgical scrub with antiseptic foam and omission of a 5 % chlorhexidine gluconate preoperative hair wash were both associated with increased shunt infection. Twelve studies evaluated the effect of a single intervention. Only antibiotic-impregnated suture, a no-shave policy, and double gloving with glove change prior to shunt handling, were associated with a significant reduction in shunt infection. In a hospital with high methicillin-resistant staphylococcus aureus (MRSA) prevalence, a randomized controlled trial found that perioperative vancomycin rather than cefazolin significantly reduced shunt infection rates. Despite wide variation in compliance rates, the implementation of comprehensive surgical protocols reduced shunt infection in all published studies. Antibiotic-impregnated suture, a no-shave policy, double gloving with glove change prior to device manipulation, and 5 % chlorhexidine hair wash were associated with significant reductions in shunt infection.

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

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

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

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

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

The objective of this systematic review and meta-analysis was to answer the following question: Are antibiotic-impregnated shunts (AISs) superior to standard shunts (SSs) at reducing the risk of shunt infection in pediatric patients with hydrocephalus? Both the US National Library of Medicine PubMed/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to AIS use in children. Abstracts were reviewed, after which studies meeting the inclusion criteria were selected. An evidentiary table was assembled summarizing the studies and the quality of their evidence (Classes I-III). A meta-analysis was conducted using a random-effects model to calculate a cumulative estimate of treatment effect using risk ratio (RR). Heterogeneity was assessed using the chi-square and I(2) statistics. Based on the quality of the literature and the result of the meta-analysis, a recommendation was rendered (Level I, II, or III). Six studies, all Class III, met our inclusion criteria. All but one study focused on a retrospective cohort and all but one were conducted at a single institution. Four of the studies failed to demonstrate a lowered infection rate with the use of an AIS. However, when the data from individual studies were pooled together, the infection rate in the AIS group was 5.5% compared with 8.6% in the SS group. Using a random-effects model, the cumulative RR was 0.51 (95% CI 0.29-0.89, p < 0.001), indicating that a shunt infection was 1.96 times more likely in patients who received an SS. We recommend AIS tubing because of the associated lower risk of shunt infection compared to the use of conventional silicone hardware (quality of evidence: Class III; strength of recommendation: Level III). Antibiotic-impregnated shunt (AIS) tubing may be associated with a lower risk of shunt infection compared with conventional silicone hardware and thus is an option for children who require placement of a shunt. Level III, unclear degree of clinical certainty.

The Clinical and Economic Value of Antibiotic-Impregnated Shunt Catheters (AISC) in the Treatment of Hydrocephalus.

The Clinical and Economic Value of Antibiotic-Impregnated Shunt Catheters (AISC) in the Treatment of Hydrocephalus.

Response to validity of the results of a perioperative protocol to reduce shunt infections

Comment to Dr. Kshettry We thank Dr. Varun R Kshettry for comments on our article “Significant reduction of shunt infection rate in children below 1 year of age after implementation of a perioperative protocol”. The impact of using antibiotic-impregnated shunt (AIS) catheters is relevant, and something we considered during the statistical analyses of the material. While the AIS catheters were used at the discretion of the treating physician, a number of surgeons were performing the shunt operations. During the study period, the department had not implemented a strict protocol on the use of AIS catheters. The decision to use an AIS catheter was subjective to the surgeon. Hence, the AIS catheters were not used exclusively in the high-risk population. Based on our available information, we cannot conclude that the use of AIS catheters made a systematic impact, or that those receiving AIS catheters were more at risk for infection. Accordingly, while Dr. Kshettry makes an important comment regarding the use of AIS catheters, we have no reason to believe that this aspect significantly affects the conclusions of our work. Nevertheless, in a continued effort to reduce shunt infection rate, we recommend more extensive use of AIS catheters together with better protocol compliance.

Letter to the Editor: Validity of the results of a perioperative protocol to reduce shunt infections

Dear Editor, I read with interest the article by Hommelstad et al. demonstrating a reduction in shunt infection rates, primarily in children below 1 year of age, after implementation of a perioperative protocol [1]. I would like to highlight a potential limitation in the study methodology that could significantly impact the interpretation of the efficacy of their perioperative protocol. Although not listed as part of the protocol, the authors state that in the post-protocol cohort, antibiotic-impregnated shunt (AIS) catheters were used at the discretion of the treating physician. AIS catheters were used in 200 (21.6 %) of the procedures post-protocol compared to zero in the pre-protocol cohort. In patients less than 1 year in age, 52 % received an AIS catheter post-protocol. AIS catheters were selectively used in patients considered to be at high risk for shunt infection. The authors state that there was no significant difference in infection rate between the 200 AIS catheter operations compared to the 727 non-AIS catheter operations (p=0.935). In patients less than 1 year of age, there was also no statistically significant difference in infection rate between AIS and non-AIS operations, although with a lower p-value (0.179). The authors interpret this finding to indicate that AIS catheters did not contribute significantly to the reduction in shunt infection in the post-protocol cohort. However, the selection bias in this statistical comparisonmust not be overlooked. One would expect a significantly higher infection rate in the highrisk population, so the finding that a high-risk population receiving AIS catheters had a similar infection rate to a lowrisk population receiving non-AIS catheters should be interpreted as possible evidence that AIS catheters resulted in a reduction of shunt infection. In the pediatric population, a recent meta-analysis revealed that shunt infection occurred in 11.2 % of non-AIS versus 5.0 % of AIS catheter procedures [2]. In the trial by Hommelstad et al., the use of AIS catheters in patients deemed to be at high risk should be considered as part of the new protocol introduced by the authors. As a result, the true effect of the perioperative protocol in the absence of AIS catheters remains uncertain.

The impact of antibiotic-impregnated catheters on ventriculoperitoneal shunt infection.

Ventriculoperitoneal shunt infections remain an important problem and result mainlyfrom perioperative colonization of shunt components by skin flora. Antibiotic-impregnated shunts have been designed to prevent such colonization. T'his study evaluates the incidence of shunt infection after the insertion of antibiotic-impregnated shunts in a population of children with hydrocephalus. All pediatric patients who had undergone cerebrospinal fluid shunt insertion retrospectively were reviewed over a 6-year period between May 2004 and December 2010. The primary outcome measure was the rate of shunt infections. Patients were followed up with for an average of 26.2 months after shunt surgery, and shunt infections were evaluated. A total of 123 pediatric patients underwent 211 shunt placement procedures. Of these operations, 193 (91%) were performed with nonimpregnated catheters and 18 shunts (9%) were placed with antibiotic-impregnated shunt catheters. Of the patients with nonimpregnated catheters, 12 (6%) experienced shunt infection, whereas none of the patients with antibiotic-impregnated catheters experienced shunt infection within the 26.2-month follow-up period (P < 0.01). The antibiotic-impregnated catheters significantly reduced the incidence of shunt infection in children with hydrocephalus during the postoperative period. Antibiotic-impregnated catheters are effective devices to prevent perioperative colonization of shunt components.

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

Antibiotic-impregnated shunts have yet to find widespread use in the developing world, largely due to cost. Given potential differences in the microbial spectrum, their effectiveness in preventing shunt infection for populations in low-income countries may differ and has not been demonstrated. This study is the first to compare the efficacy of a Bactiseal shunt system with a non-antibiotic-impregnated system in a developing country. The Bactiseal Universal Shunt (BUS) was placed in 80 consecutive Ugandan children who required a shunt. In this retrospective cohort study, the outcome for that group was compared with the outcome for the immediately preceding 80 consecutive children in whom a Chhabra shunt had been placed. The primary end points were shunt failure, shunt infection, and death. Shunt survival was analyzed using the Kaplan-Meier method. Significance of differences between groups was tested using the log-rank test, chi-square analysis, Fisher's exact test, and t-test. There was no difference between groups in regard to age, sex, or etiology of hydrocephalus. Mean follow-up for cases of nonfailure was 7.6 months (median 7.8 months, interquartile range 6.5-9.5 months). There was no significant difference between groups for any end point. The BUS group had fewer infections (4 vs 11), but the difference was not significant (p = 0.086, log-rank test). Gram-positive cocci were the most common culturable pathogens in the Chhabra group, while the only positive culture in the BUS group was a gram-negative rod. These results provide equipoise for a randomized controlled trial in the same population and this has been initiated. It is possible that the observed trends may become significant in a larger study. The more complex task will involve determining not only the efficacy, but also the cost-effectiveness of using antibiotic-impregnated shunt components in limited-resource settings.

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

Infection after both primary and revision shunt surgeries remains a major problem in pediatric neurosurgical practice. Antibiotic-impregnated shunt (AIS) tubing has been proposed to reduce infection rates. The authors report their experience with AIS catheters in their large pediatric neurosurgery department. The authors conducted a retrospective case review of consecutive shunt operations performed before (1993-2003) and after (2005-2009) introduction of AIS tubing, with analysis of shunt infection rates and causative organisms identified. The historical control group consisted of 1592 consecutive shunt operations (657 primary insertions), and the AIS study group consisted of 500 consecutive shunt operations (184 primary insertions). Patients ranged in age from 0-17 years. In the historical group, 135 infections were identified (8.4%). In the AIS study group, 25 infections were identified (5%), representing a significant reduction (p < 0.005). The latency to diagnosis of infection was 23 days in the historical group and 139 days in the AIS study group. The infection rates in infants 0-6 months of age were 12.2% (historical group) and 6.7% (AIS group, p < 0.005), and in infants 7-12 months of age the rates were 7.9% (historical group) and 2.7% (AIS group, p < 0.005). In the historical control group, the frequency rank order of causative organisms was coagulase-negative staphylococcus (51.9%), Staphylococcus aureus (31.6%), streptococcus or enterococcus spp. (8.8%), gram-negative organisms (4.4%), and Propionibacterium acnes (2.2%). Organisms responsible for infections in AIS were S. aureus (40%), followed by streptococcus or enterococcus spp. (20%), P. acnes and coagulase-negative staphylococcus (both 16%), and gram-negative organisms (4%). No unusually antibiotic-resistant bacteria were identified in either group. The authors further subdivided the AIS group into those undergoing primary AIS insertion (Subgroup 1), those undergoing revision of non-AIS systems using AIS components (Subgroup 2), and those undergoing revision of AIS systems using AIS components (Subgroup 3). Infection rates were 1.6% in Subgroup 1, 2.5% in Subgroup 2, and 11.7% in Subgroup 3. Staphylococcus aureus was the most common organism identified in infections of the Subgroups 2 and 3. Use of AIS tubing significantly improves shunt infection rates in both general pediatric and infant populations with no evidence of increased antibiotic resistance, which is in agreement with previous studies. However, the increased infection rate in revision surgery in children with AIS catheters in situ raises questions about their long-term application.

121 Cost-Consequence Analysis of Antibiotic-Impregnated Shunts and External Ventricular Drains (EVDs) in Hydrocephalus

121 Cost-Consequence Analysis of Antibiotic-Impregnated Shunts and External Ventricular Drains (EVDs) in Hydrocephalus

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

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. 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. 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. 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.