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

Implementation of an adapted perioperative ventriculoperitoneal shunting protocol in a tertiary center located in a low-to-middle-income country

OBJECTIVE

Preventative protocols have efficaciously reduced shunt infection in developed countries. However, the generalizability of these protocols in low-to-middle-income countries (LMICs) remains unclear. Previously, shunt insertion in the authors' center was routinely performed under institutional preventative precautions, which was updated via merging with the Hydrocephalus Clinical Research Network (HCRN) protocol. This study aimed to investigate the ventriculoperitoneal shunt (VPS) infection rates in pediatric patients following the implementation of the adapted protocol.

METHODS

The adapted protocol was implemented in all first-time VPS implantations between 2011 and 2021. The primary outcome was a 6-month shunt infection. The Pearson chi-square test was used for categorical variables and the Mann-Whitney U-test for numeric variables to evaluate the correlation with shunt infection.

RESULTS

A total of 352 first-time VPS procedures were performed adhering to the adapted protocol. The median age was 5 months, and 189 (53.7%) were male. Overall, 37 patients (10.5%) experienced shunt infection, with 30 (8.5%) occurring within the first 6 months, which was lower than 13.3% infection rate of the previous series of the same center. The infection rate was slightly higher than the 5.7% and 6.0% rates reported by HCRN studies. Patients with shunt infection were significantly younger (7.5 versus 17.5 months, P < 0.001).

CONCLUSIONS

This study validates the efficacy of an adapted perioperative protocol in mitigating shunt infection in a high-volume center in a LMIC. Adhering to a step-by-step protocol, modified to suit the healthcare resources and financial constraints of LMICs, could maintain low shunt infection rates that are roughly comparable to those of centers in high-income countries.

A systematic review of the power of standardization in pediatric neurosurgery

In the current neurosurgical field, there is a constant emphasis on providing the best care with the most value. Such work requires the constant optimization of not only surgical but also perioperative services. Recent work has demonstrated the power of standardized techniques in limiting complication while promoting optimal outcomes. In this review article, protocols addressing operative and perioperative care for common pediatric neurosurgical procedures are discussed. These articles address how various institutions have optimized procedures through standardization. Our objective is to improve patient outcomes through the optimization of protocols.

Surgical instruments and catheter damage during ventriculoperitoneal shunt assembly

OBJECTIVE

Current surgical techniques use common surgical instruments for sterile shunt assembly. This study investigated the impact of using these techniques and surgical instruments on the mechanical integrity of the ventriculoperitoneal shunt system, specifically shunt catheters.

METHODS

The authors conducted failure testing on 85 rifampin-coated catheters and 85 barium-impregnated catheters using 5 different surgical instruments and 2 different surgical techniques. In technique A, the distal end of the catheter was pushed onto the shunt valve inlet connector with the surgical instrument. In technique B, the catheter was pulled over the inlet connector. One hundred sixty catheters underwent 10-repetition-maximum testing, in which the catheter either failed before completion of 10 consecutive assembly/disassembly repetitions or the catheter completed 10 consecutive repetitions. The authors also conducted 100-repetition-maximum tests on 5 barium-impregnated and 5 rifampin-coated catheters using technique A.

RESULTS

Catheter failure rates were significantly different among the different instruments used in assembly (p ≤ 0.001). Post hoc analysis showed that using mosquito forceps with shods resulted in a significantly lower catheter failure rate than the other instruments (p < 0.0005). The catheter failure rate of technique A was significantly lower than that of technique B (5% vs 81%, p < 0.001). There was no statistical difference between the failure rates of the barium and rifampin catheters (42% vs 44%, p = 0.9), but the barium catheters outperformed the rifampin catheters in the 100-repetition-maximum trials (p = 0.02). Instrument type (p = 0.0232) and catheter type (p = 0.0096) were both significant factors in determining the number of assembly/disassembly repetitions needed to cause catheter failure. It took an average of 2.79 repetitions of assembly/disassembly to cause catheter failure. DeBakey forceps had significantly lower mean repetitions to failure (mean 1.38) than the Gerald forceps without teeth (mean 2.73, p = 0.05) and bayonet (mean 3.25, p = 0.02).

CONCLUSIONS

This study was the first of its kind to analyze how physical manipulation affects the mechanical integrity of ventriculoperitoneal shunt components. The authors demonstrated a significantly lower shunt catheter failure rate when mosquito forceps with shods and technique A were used in assembly. Moreover, the authors established that use of DeBakey forceps resulted in failure with fewer assembly/disassembly repetitions than use of the Gerald and bayonet forceps, suggesting that DeBakey forceps are the most damaging instrument.

Reducing ventriculoperitoneal shunt infection with intraoperative glove removal

BACKGROUND

Contamination of ventriculoperitoneal shunts (VPS) by cutaneous flora, particularly coagulase-negative staphylococci, is a common cause of shunt infection and failure, leading to prolonged hospital stay, higher costs of care, and poor outcomes. Glove contamination may occur during VPS insertion, increasing risk of such infections.

METHODS

We performed a systematic search of the PubMed database for studies published January 1, 1970, through August 31, 2021 that documented VPS infection rates before and after implementing a practice of double gloving with change or removal of the outer glove immediately prior to shunt insertion.

RESULTS

Among 272 reports screened, 4 were eligible for review based on our inclusion criteria. The incidence of VPS infection was reduced in all 4 quasi-experimental studies with an aggregate incidence of VPS infection of 11.8% before the change in intraoperative protocol and 4.9% after protocol change. One study documented reduced hospital stay with this change in protocol.

CONCLUSION

The risk of VPS infection is reduced by removal or replacement of the outer surgical gloves immediately prior to intraoperative insertion of a VPS as part of an infection control bundle.

A standardized infection prevention bundle for reduction of CSF shunt infections in adult ventriculoperitoneal shunt surgery performed without antibiotic-impregnated catheters

OBJECTIVE

Ventriculoperitoneal (VP) shunt insertion and revision surgeries are some of the most common procedures that are performed by neurosurgeons. Shunt infections within the adult population are associated with significant morbidity and mortality and rates remain high. The objective of the current study was to use quality improvement (QI) methodology to create a standardized infection prevention bundle aimed at reducing the rate of shunt infections.

METHODS

A prospective, single-center, single-surgeon QI study was undertaken. Patients were included if they were 18 years of age or older and were undergoing a VP shunt insertion or revision. The primary outcome of the study was the development of a shunt-related surgical site infection, within 1 year of surgery, as defined according to the Canadian Nosocomial Infection Surveillance Program guidelines. There was no standardized protocol prior to July 2013. A bundle coined as the Calgary Adult Shunt Infection Prevention Protocol (CASIPP) was implemented on July 1, 2013, and updated on July 1, 2015, when 2% chlorhexidine gluconate in 70% isopropyl alcohol replaced povidone-iodine for preoperative skin antisepsis. Protocol compliance was regularly monitored using a standardized process. No antibiotic-impregnated catheters were used.

RESULTS

A total of 621 consecutive VP shunt insertions and revisions were included in the study. The rate of shunt infection was 5.8% during the period in which there was no standardized shunt protocol. After the implementation of the CASIPP the infection rate decreased to 4.0%, and after introduction of the chlorhexidine/alcohol skin antisepsis, the infection rate was 0% in 379 consecutive procedures (p < 0.0001). Multivariable logistic regression analysis demonstrated that the use of chlorhexidine/alcohol with CASIPP was associated with a significant reduction in the odds of developing a shunt infection (OR 0.032, 95% CI 0-0.19, p = 0.0005).

CONCLUSIONS

The implementation of a standardized shunt infection prevention bundle within the adult population, without the use of antibiotic-impregnated catheters, significantly reduced the rate of shunt infections which was sustained over many years. The use of 2% chlorhexidine gluconate in 70% isopropyl alcohol for preoperative antisepsis may have played a significant role. Multicenter studies should be completed to verify the effectiveness of the authors' protocol.

Current Perspectives on the Diagnosis and Management of Healthcare-Associated Ventriculitis and Meningitis

Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

Indian Society of Pediatric Neurosurgery Consensus Guidelines on Preventing and Managing Shunt Infection: Version 2020-21

Background

Shunt infection is the most significant morbidity associated with shunt surgery. Based on the existing literature for the prevention and management of shunt infection, region and resource-specific recommendations are needed.

Methods

In February 2020, a Guidelines Development Group (GDG) was created by the Indian Society of Paediatric Neurosurgery (IndSPN) to formulate guidelines on shunt infections, which would be relevant to our country and LMIC in general. An initial email survey identified existing practices among the membership of the IndSPN, and eight broad issues pertaining to shunt infection were identified. Next, members of the GDG performed a systematic review of the literature on the prevention and management of shunt infection. Then, through a series of virtual meetings of the GDG over 1 year, evidence from the literature was presented to all the members and consensus was built on different aspects of shunt infection. Finally, the guidelines document was drafted and circulated among the GDG for final approval. Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to grade the evidence and strength of recommendation.

Results

The guidelines are divided into eight sections. Level I and Level II evidence was available for only five recommendations and led to a moderate level of recommendations. Most of the available evidence was at Level III and below, and hence the level of recommendation was low or very low. A consensus method was used to provide recommendations for several issues.

Conclusions

Although most of the recommendations for the prevention and management of shunt infections are based on a low level of evidence, we believe that this document will provide a useful reference to neurosurgeons not only in India but also in other low and middle income countries. These guidelines need to be updated as and when new evidence emerges.

Shunt infection and malfunction in patients with myelomeningocele

OBJECTIVE

Myelomeningocele (MMC) is frequently complicated by symptomatic hydrocephalus, necessitating early permanent CSF diversion and revision surgeries. Shunt infections are a common cause of shunt malfunction. This study aims to characterize long-term shunt-related outcomes of patients undergoing MMC closure.

METHODS

A total of 170 patients undergoing MMC closure between the years of 1995 and 2017 were identified from a retrospective review of a prospectively populated surgical database at the Children's Hospital of Pittsburgh. Patients who underwent MMC closure and required ventriculoperitoneal (VP) shunt insertion met criteria and were included in the primary study analysis. Analysis with a Fisher exact test was performed for categorical variables, and Mann-Whitney U-tests were utilized for numerical data.

RESULTS

Of the 158 total patients undergoing MMC closure and meeting inclusion criteria, 137 (87%) required VP shunt insertion. These 137 patients demonstrated a shunt revision rate of 21.1% per person-year and a shunt infection rate of 2.1% per person-year over a mean follow-up of 10.8 years. Patients had a mean of 3.4 ± 0.6 shunt surgeries prior to their first infection. Patients undergoing immediate shunt removal, external ventricular drain placement, or shunt replacement after clearing the infection had lower rates of subsequent infections than patients who initially were managed with shunt externalization (p < 0.001). Placement of a shunt at the time of MMC closure was not found to be a risk factor for infection. Of patients with initial shunt placement after the implementation of the Hydrocephalus Clinical Research Network protocol in 2011, the authors' institution has had a shunt infection rate of 4.2% per person-year and a revision rate of 35.7% per person-year.

CONCLUSIONS

This study describes long-term outcomes of shunted MMC patients and factors associated with shunt infections. Most patients underwent multiple revisions prior to the first shunt infection. Shunt externalization may be ineffective at clearing the infection and should be avoided in favor of early shunt removal and external ventricular drainage, followed by shunt replacement once infection is demonstrated to have cleared.

Manual Shunt Connector Tool to Aid in No-Touch Technique

BACKGROUND

Given the morbidity and cost associated with cerebrospinal fluid shunt infections, many neurosurgical protocols implement "no-touch" technique to minimize infection. However, current surgical tools are not designed specifically for this task and surgeons often resort to using their hands to connect the shunt catheter to the valve.

OBJECTIVE

To develop an efficient and effective shunt assembly tool.

METHODS

Prototypes were designed using computer assisted software and machined in stainless steel. The amount of time and number of attempts it took volunteers to connect a Bacticel shunt catheter to a Delta valve were recorded using the new tool and standard shodded mosquitos. Scanning electron microscopy (SEM) was done on manipulated catheters to assess potential damage. Practicing neurosurgeons provided feedback.

RESULTS

Nonsurgeon (n = 13) volunteers and neurosurgeons (n = 6) both completed the task faster and with fewer attempts with the new tool (mean 7.18 vs 15.72 s and 2.00 vs 6.36 attempts, P < .0001; mean 2.93 vs 5.96 s and 1.06 vs 2.94 attempts, P < .001, respectively). SEM of 24 manipulated catheters showed no microscopic damage. 100% of neurosurgeons surveyed (n = 10) would adapt the tool in their practice, 90% preferred use of the new tool compared to their existing method, and 100% rated it easier to use compared to existing instruments.

CONCLUSION

The new tool shortened the time and number of attempts to connect a shunt catheter to a valve. Neurosurgeons preferred the new tool to existing instruments. There was no evidence of catheter damage with the use of this tool.

Global trends in the evaluation and management of cerebrospinal fluid shunt infection: a cooperative ISPN survey

INTRODUCTION

Ventriculoperitoneal shunts (VPS) is commonly performed by pediatric neurosurgeons and there is no consensus in management of VPS infection as it relates to diagnosis and treatment.

OBJECTIVE

We utilized an international practitioner-based survey to study the variability in VPS infection diagnostic and therapeutic measures.

METHODS

A survey gauging practice patterns of pediatric neurosurgeons regarding VPS and its complication management was distributed. Survey endpoints were analyzed by VPS case volume and pediatric-focused case volume regarding diagnostic measures, use of cerebrospinal fluid (CSF) profile, microbiology, and treatment.

RESULTS

A total of 439 surveys were distributed, with a response rate of 31%. Responders ranged from Americas (44.9%), European (31.4%), Asian (18.6%), African (2.5%), to Australian continents (2.5%). Practitioners were stratified based on number and percentage pediatric VPS performed. Institutions performing highest VPS and percentage pediatric case volumes had lower rate of VPS infection. Shunt tap was the most widely used diagnostic study. Overall CSF profile did not affect decision making towards VPS internalization, except for leukocyte count ≤ 20 × 10⁹/L. Practitioners utilized 3 negative cultures prior to VPS internalization. Discrepancies in surgical management were noted amongst centers with high versus low VPS volume and proportion of pediatric-focused case volume. Practice patterns were not noted to be organism dependent. Antibiotic-impregnated shunts were utilized in the Americas and Europe over other regions but only in one third of all initial VPS or as a preventive strategy after a VPS infection has been resolved respectively.

DISCUSSION

Survey results from 6 continents in VPS management revealed patterns of lower infection in high-volume centers, 3 negative cultures prior to internalization and aggressive surgical VPS infection management in high-volume institutions.

Contemporary management and outcome of myelomeningocele: the Rotterdam experience

OBJECTIVE

Myelomeningocele (MMC) is the most common form of spina bifida, with a lifelong impact on the quality of life for infants born with this condition. In recent decades, fetal surgery has evolved from an experimental therapy to standard of care for many centers in the world. In this study, the authors aimed to provide an overview of the current management and outcomes for infants with MMC managed at their institution. This then provides a center-specific historical cohort for comparison with future antenatal-treated MMC cases.

METHODS

This is a retrospective, single-institution cohort study including all consecutive MMC cases between January 1, 2000, and June 1, 2018, at Erasmus MC. Outcome data included closure of the defect (location, timing, and surgical parameters), hydrocephalus management, Chiari malformation type II (CMTII) management, incidence of spinal cord tethering and outcome, motor outcomes, and continence.

RESULTS

A total of 93 patients were included with predominantly lumbosacral lesions. Two patients died during follow-up. Hydrocephalus was present in 84%, with a 71% ventriculoperitoneal shunt reoperation rate. Surgery was performed in 12% for a tethered spinal cord at a mean age of 8 years. Decompression surgery was performed in 3 patients for CMTII. Special education in 63% was significantly associated with hydrocephalus (p < 0.015). Nineteen percent of patients were able to walk independently, and 47% were nonambulators. Social continence for urine was obtained in 75% of patients, 4% had fecal incontinence.

CONCLUSIONS

This study provides an overview of current MMC outcomes at the authors' center and will serve as a historical cohort for comparison with future fetal surgery cases operated on at the center in the coming years. Apart from a relatively low surgical untethering rate, the authors' outcome data are comparable to those in the literature. Hydrocephalus is highly prevalent in postnatally treated MMC patients; in this study as in much of the literature, hydrocephalus is correlated with a low cognitive function. Fetal surgery for MMC halves the need for shunt treatment in a select group of MMC pregnancies, constituting a major indication for us to undergo the transition to a fetal surgery center. The fetal benefits of open antenatal surgery for MMC are well established, yet long-term data on especially tethered spinal cord are eagerly awaited.

Ventriculoperitoneal Shunt Complication in Pediatric Hydrocephalus: Risk Factor Analysis from a Single Institution in Nepal

Objective:

Ventriculoperitoneal (VP) shunt surgery is one of the commonly performed neurosurgical procedures. Complications due to shunt failure are associated with high morbidity and mortality. We report an analysis of risk factors for shunt failure in pediatric patients from a single institution in Nepal.

Materials and Methods:

A retrospective analytical study with prospective data was designed. All children younger than 15 years, with first time VP shunting, at a tertiary government hospital in Kathmandu during 2014-2017 were followed up. Association of independent variables with the primary outcome variable (complication of VP shunt) was analyzed using Chi-square test. Bivariate logistic regression was performed to identify unadjusted odds ratio (OR) with 95% confidence interval (CI). Multivariate logistic regression model was designed to calculate adjusted OR with 95% CI.

Results:

Of 120 patients, more than half (55.8%) of the patients were male. Mean age was 62.97 months. Maximum duration of follow-up was 30 months. Most common cause of hydrocephalus was congenital aqueductal stenosis (40.8%) followed by tumors (29.2%). Overall shunt complication was found in 26.7% (95% CI 19.0%–35.5%). Shunt infection was seen in 5% while malfunction without infection was found in 21.7%. Bivariate logistic regression showed duration of surgery more than 1 h (OR 2.67, 95% CI 1.11–6.42, P = 0.028) compared to 1 h or less, experienced surgeon (OR 0.37, 95% CI 0.16–0.89, P = 0.026) compared to residents, and emergency surgery (OR 3.97, 95% CI 1.69–9.29, P = 0.001) compared to elective surgery as significant risk factors, while emergency surgery was the only significant variable for shunt failure on multivariate regression analysis (OR 3.3, 95% CI 1.16–9.35, P = 0.025).

Conclusion:

Longer duration of surgery, less experience of the surgeon, and the priority of the case (emergency) were independent risk factors for shunt complications.

Application of the Preventable Shunt Revision Rate to an Adult Population

BACKGROUND

The preventable shunt revision rate (PSRR) was recently introduced in pediatric hydrocephalus as a quality metric for shunt surgery. We evaluated the PSRR in an adult hydrocephalus population.

METHODS

All ventricular shunt operations (January 1, 2013 to March 31, 2018) performed at a university-based teaching hospital were included. For any index surgery (de novo or revision) resulting in reoperation within 90 days, the index surgery details were collected, and a consensus decision was reached regarding whether the failure had been potentially avoidable. Preventable failure was defined as failure due to infection, malposition, disconnection, migration, or kinking. The 90-day shunt failure rate and PSRR were calculated. Bivariate analyses were performed to evaluate the individual effects of each independent variable on preventable shunt failure.

RESULTS

A total of 318 shunt operations had been performed in 245 patients. Most patients were women (62%), with a median age of 48.2 years (interquartile range, 31.2-63.2 years). Most had had ventriculoperitoneal shunts placed (86.5%), and just more than one half were new shunts (51.6%). A total of 53 cases (16.7%) in 42 patients experienced shunt failure within 90 days of the index operation. Of these, 27 failures (8.5% of the total cases; 51% of the failures) were considered potentially preventable. The most common reasons were infection (37%; n = 10) and malposition of the proximal and distal catheters (both 25.9%; n = 7). Age was the only statistically significant difference between the 2 groups, with the patients experiencing preventable shunt failure older than those without preventable shunt failure (51.4 vs. 37.1 years; P = 0.017).

CONCLUSIONS

The 90-day PSRR can be applied to an adult population and serve as a quality metric.