Hydrocephalus Clinical Research Network Research Articles

Re-examining the classification of abdominal pseudocysts as surgical site infections through review of broad-range polymerase chain reaction results

BackgroundThe Hydrocephalus Clinical Research Network–quality group (HCRNq) historically defined all abdominal pseudocysts associated with a ventriculoperitoneal shunt as a surgical site infection regardless of culture result. MethodsWe retrospectively reviewed broad-range polymerase chain reaction (BRPCR) results sent between January 2017 and July 2023 from abdominal pseudocyst fluid sent from hospitals around the country to a reference laboratory to help further characterize these collections. ResultsA total of 19 samples were tested via BRPCR between 1/2017 and 7/2023. Two (10.5 %) had organisms identified; one with Staphylococcus epidermidis and one with Candida parapsilosis. No fastidious organisms that would be expected to not grow with typical culture techniques were identified. ConclusionsFew abdominal pseudocysts had organisms identified by BRPCR, suggesting that not all pseudocysts are due to infectious causes. Consideration should be given to alternate causes of pseudocyst development when cultures are negative.

Infection rates during eras of intrathecal antibiotic use followed by antibiotic-impregnated catheter use in prevention of cerebrospinal fluid shunt infection.

The Hydrocephalus Clinical Research Network (HCRN) implemented a perioperative infection prevention bundle for all CSF shunt surgeries in 2007 that included the relatively unproven technique of intrathecal instillation of the broad-spectrum antibiotics vancomycin and gentamicin into the shunt. In the meantime, the field debated the use of antibiotic-impregnated catheter (AIC) shunt tubing using clindamycin and rifampin, an increasingly widespread, but expensive and controversial, technique. It is unknown whether there were changes in infecting organisms associated with the use of these techniques during CSF shunt surgery at the hospital level. Key comparison periods include during the use of intrathecal antibiotics (period 1 from June 1, 2007, to December 31, 2011, at HCRN hospitals) and AIC (period 2 from January 1, 2012, to December 31, 2015, at HCRN as well as increasing over time at non-HCRN hospitals) and only standard use of routine prophylactic antibiotics (period 1 at non-HCRN hospitals). The aim of this study was to examine rates of CSF shunt surgery-related infections from 2007 to 2012 at the hospital level, including HCRN and non-HCRN hospitals, with a focus on infections with gram-negative organisms. The authors conducted a retrospective observational cohort study at 6 children's hospitals with enrollment from 2007 to 2012 and surveillance through 2015. Bimonthly rates of shunt surgery-related infections were summarized to produce an overall hospital-specific time series, as well as by HCRN/non-HCRN status. An interrupted time series analysis was performed to assess the impact of change in HCRN perioperative infection prevention bundle on overall bimonthly infection rates. Quarterly rates of gram-negative shunt surgery-related infections were summarized to produce an overall hospital-specific time series. The overall bimonthly CSF shunt infection rate over time did not change significantly from 2007 to 2012. There was no difference in the trajectory of infection rates between HCRN and non-HCRN hospitals during the entire study period. No change in distributions of gram-negative organism infections was observed in hospitals from 2007 to 2015. There were no differences observed in hospital-level infection rates for low-risk patients undergoing CSF shunt surgery. This included analyses based on participation in the HCRN network, given their regular use of intrathecal antibiotics in period 1 and a focus on gram-negative infections with increasing adoption of AICs in period 2.

Comparing ventriculoatrial and ventriculopleural shunts in pediatric hydrocephalus: a Hydrocephalus Clinical Research Network study.

When the peritoneal cavity cannot serve as the distal shunt terminus, nonperitoneal shunts, typically terminating in the atrium or pleural space, are used. The comparative effectiveness of these two terminus options has not been evaluated. The authors directly compared shunt survival and complication rates for ventriculoatrial (VA) and ventriculopleural (VPl) shunts in a pediatric cohort. The Hydrocephalus Clinical Research Network Core Data Project was used to identify children ≤ 18 years of age who underwent either VA or VPl shunt insertion. The primary outcome was time to shunt failure. Secondary outcomes included distal site complications and frequency of shunt failure at 6, 12, and 24 months. The search criteria yielded 416 children from 14 centers with either a VA (n = 318) or VPl (n = 98) shunt, including those converted from ventriculoperitoneal shunts. Children with VA shunts had a lower median age at insertion (6.1 years vs 12.4 years, p < 0.001). Among those children with VA shunts, a hydrocephalus etiology of intraventricular hemorrhage (IVH) secondary to prematurity comprised a higher proportion (47.0% vs 31.2%) and myelomeningocele comprised a lower proportion (17.8% vs 27.3%) (p = 0.024) compared with those with VPl shunts. At 24 months, there was a higher cumulative number of revisions for VA shunts (48.6% vs 38.9%, p = 0.038). When stratified by patient age at shunt insertion, VA shunts in children < 6 years had the lowest shunt survival rate (p < 0.001, log-rank test). After controlling for age and etiology, multivariable analysis did not find that shunt type (VA vs VPl) was predictive of time to shunt failure. No differences were found in the cumulative frequency of complications (VA 6.0% vs VPl 9.2%, p = 0.257), but there was a higher rate of pneumothorax in the VPl cohort (3.1% vs 0%, p = 0.013). Shunt survival was similar between VA and VPl shunts, although VA shunts are used more often, particularly in younger patients. Children < 6 years with VA shunts appeared to have the shortest shunt survival, which may be a result of the VA group having more cases of IVH secondary to prematurity; however, when age and etiology were included in a multivariable model, shunt location (atrium vs pleural space) was not associated with time to failure. The baseline differences between children treated with a VA versus a VPl shunt likely explain current practice patterns.

Trends in the Treatment of Pediatric Hydrocephalus Since 2014: Understanding the Role of the 2014 Hydrocephalus Guidelines

BACKGROUND AND OBJECTIVES: The management of hydrocephalus has significantly changed over the past decade. Endoscopic third ventriculostomy has become more prevalent, and shunt surgery has become more protocolized through research efforts by the Hydrocephalus Clinical Research Network. In 2014, the Pediatric Hydrocephalus Guidelines were first published, providing a cohesive source for clinical guidance. We planned to investigate national trends in the management of pediatric hydrocephalus after the publication of the 2014 Pediatric Hydrocephalus Guidelines as guidelines act as a compilation of historic and recent literature in a scientific field. METHODS: A multipronged approach was used to evaluate changes in the treatment of pediatric hydrocephalus since 2014. First, we queried the Pediatric Health Information System between 2013 and 2018 to identify national trends in shunt procedures for hydrocephalus. To assess the recommendation in the guidelines to use antibiotic-impregnated catheters (AICs) in shunts, national sales records of AICs were obtained from 2 large neurosurgical device companies. RESULTS: A total of 11,179 shunt procedures were performed within the Pediatric Health Information System database in the study period. In the preguideline publication period (2013-2014), there was a shunt revision-to-placement ratio of 1.63 while in the postguideline publication period (2015-2018), there was a ratio of 0.84 (P &lt; .0001). National sales data revealed that antibiotic-impregnated drain sales increased from 2% to 77% since publication. CONCLUSION: Findings from this investigation suggest progress in pediatric hydrocephalus management since 2014. The shunt revision-to-placement ratio improved, and the use of AICs increased over this period. Improved outcomes are likely associative findings rather than causative with the guidelines representing a culmination of widespread changes in hydrocephalus care such as increased use of endoscopic third ventriculostomies, protocolized care, and image-guided shunt placement. Further research into the impact of clinical practice guidelines is needed to better understand the impact of this tool on surgeons and patient care.

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

BackgroundCerebrospinal fluid (CSF) shunts allow children with hydrocephalus to survive and avoid brain injury (J Neurosurg 107:345-57, 2007; Childs Nerv Syst 12:192-9, 1996). The Hydrocephalus Clinical Research Network implemented non-randomized quality improvement protocols that were shown to decrease infection rates compared to pre-operative prophylactic intravenous antibiotics alone (standard care): initially with intrathecal (IT) antibiotics between 2007–2009 (J Neurosurg Pediatr 8:22-9, 2011), followed by antibiotic impregnated catheters (AIC) in 2012–2013 (J Neurosurg Pediatr 17:391-6, 2016). No large scale studies have compared infection prevention between the techniques in children. Our objectives were to compare the risk of infection following the use of IT antibiotics, AIC, and standard care during low-risk CSF shunt surgery (i.e., initial CSF shunt placement and revisions) in children.MethodsA retrospective observational cohort study at 6 tertiary care children’s hospitals was conducted using Pediatric Health Information System + (PHIS +) data augmented with manual chart review. The study population included children ≤ 18 years who underwent initial shunt placement between 01/2007 and 12/2012. Infection and subsequent CSF shunt surgery data were collected through 12/2015. Propensity score adjustment for regression analysis was developed based on site, procedure type, and year; surgeon was treated as a random effect.ResultsA total of 1723 children underwent initial shunt placement between 2007–2012, with 1371 subsequent shunt revisions and 138 shunt infections. Propensity adjusted regression demonstrated no statistically significant difference in odds of shunt infection between IT antibiotics (OR 1.22, 95% CI 0.82–1.81, p = 0.3) and AICs (OR 0.91, 95% CI 0.56–1.49, p = 0.7) compared to standard care.ConclusionIn a large, observational multicenter cohort, IT antibiotics and AICs do not confer a statistically significant risk reduction compared to standard care for pediatric patients undergoing low-risk (i.e., initial or revision) shunt surgeries.

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

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. 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. A total of 352 first-time VPS procedures were performed adhering to the adapted protocol. The median age was 5months, and 189 (53.7%) were male. Overall, 37 patients (10.5%) experienced shunt infection, with 30 (8.5%) occurring within the first 6months, 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 17.5months, P < 0.001). 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 re-evaluation of the Endoscopic Third Ventriculostomy Success Score: a Hydrocephalus Clinical Research Network study.

The Hydrocephalus Clinical Research Network (HCRN) conducted a prospective study 1) to determine if a new, better-performing version of the Endoscopic Third Ventriculostomy Success Score (ETVSS) could be developed, 2) to explore the performance characteristics of the original ETVSS in a modern endoscopic third ventriculostomy (ETV) cohort, and 3) to determine if the addition of radiological variables to the ETVSS improved its predictive abilities. From April 2008 to August 2019, children (corrected age ≤ 17.5 years) who underwent a first-time ETV for hydrocephalus were included in a prospective multicenter HCRN study. All children had at least 6 months of clinical follow-up and were followed since the index ETV in the HCRN Core Data Registry. Children who underwent choroid plexus cauterization were excluded. Outcome (ETV success) was defined as the lack of ETV failure within 6 months of the index procedure. Kaplan-Meier curves were constructed to evaluate time-dependent variables. Multivariable binary logistic models were built to evaluate predictors of ETV success. Model performance was evaluated with Hosmer-Lemeshow and Harrell's C statistics. Seven hundred sixty-one children underwent a first-time ETV. The rate of 6-month ETV success was 76%. The Hosmer-Lemeshow and Harrell's C statistics of the logistic model containing more granular age and etiology categorizations did not differ significantly from a model containing the ETVSS categories. In children ≥ 12 months of age with ETVSSs of 50 or 60, the original ETVSS underestimated success, but this analysis was limited by a small sample size. Fronto-occipital horn ratio (p = 0.37), maximum width of the third ventricle (p = 0.39), and downward concavity of the floor of the third ventricle (p = 0.63) did not predict ETV success. A possible association between the degree of prepontine adhesions on preoperative MRI and ETV success was detected, but this did not reach statistical significance. This modern, multicenter study of ETV success shows that the original ETVSS continues to demonstrate good predictive ability, which was not substantially improved with a new success score. There might be an association between preoperative prepontine adhesions and ETV success, and this needs to be evaluated in a future large prospective study.

Utilization trends in cerebrospinal fluid shunt infection prevention techniques in the United States from 2007 to 2015.

The objective of this study was to describe trends in the utilization of infection prevention techniques (standard care, intrathecal [IT] antibiotics, antibiotic-impregnated catheters [AICs], and combination of IT antibiotics and AICs) among participating hospitals over time. This retrospective cohort study at six large children's hospitals between 2007 and 2015 included children ≤ 18 years of age who underwent initial shunt placement between 2007 and 2012. Pediatric Health Information System + (PHIS+) data were augmented with chart review data for all shunt surgeries that occurred prior to the first shunt infection. The Pearson chi-square test was used to test for differences in outcomes. In total, 1723 eligible children had initial shunt placement between 2007 and 2012, with 3094 shunt surgeries through 2015. Differences were noted between hospitals in gestational age, etiology of hydrocephalus, and race and ethnicity, but not sex, weight at surgery, and previous surgeries. Utilization of infection prevention techniques varied across participating hospitals. Hydrocephalus Clinical Research Network hospitals used more IT antibiotics in 2007-2011; after 2012, increasing adoption of AICs was observed in most hospitals. A consistent trend of decreasing IT antibiotic use and increased AIC utilization was observed after 2012, except for hospital B, which consistently used AICs.

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

Postoperative shunt infection is a nightmare in neurosurgical practice with additional morbidity and mortality. A lot of protocols have contributed to the reduction of ventriculoperitoneal shunt (VPS) infections but not eradication. The aim of the study was to evaluate the rigid application of a modified Hydrocephalus Clinical Research Network (HCRN) protocol in the prevention of postoperative shunt infection. We retrospectively evaluated children with congenital hydrocephalus who underwent VPS insertion, and in whom the protocol was applied from June 2019 to January 2020. Follow-up ranged from 11 to 24 months. Thirty-seven procedures were performed including 35 primary shunt insertions and two revision surgeries. The median age was 5 months (range, 1-30 months), and 25 patients were males. The most common cause for VPS placement was congenital hydrocephalus without identifiable cause in 28 cases (80%). The endoscope-assisted technique was used in the insertion of the proximal end in six cases (17%). The mean follow-up was 19.4 months (11-24 months). The rate of shunt infection was 0% till the last follow-up. The preliminary results showed an effective method for the prevention of postoperative shunt infections using the modified protocol. These initial findings need to be validated in a large prospective study before widespread application can be recommended.

Safety and effectiveness of the assessment and treatment of idiopathic normal pressure hydrocephalus in the Adult Hydrocephalus Clinical Research Network.

The aim of this study was to describe the processes and outcomes associated with patients at five sites in the Adult Hydrocephalus Clinical Research Network (AHCRN) who had undergone evaluation and treatment for suspected idiopathic normal pressure hydrocephalus (iNPH) and had 1-year postoperative follow-up. Subjects with possible iNPH who had been prospectively enrolled in the AHCRN registry between November 19, 2014, and December 31, 2018, were evaluated by CSF drainage via either lumbar puncture or external lumbar drainage, consistent with recommendations of the international iNPH guidelines. Standardized clinical evaluations of gait, cognition, urinary symptoms, depression, and functional outcomes were conducted at baseline, before and after CSF drainage, and at 4-month intervals after shunt surgery. Complications of CSF drainage and shunt surgery were recorded. Seventy-four percent (424/570) of patients with possible iNPH had CSF drainage, and 46% of them (193/424) underwent shunt surgery. The mean change in gait velocity with CSF drainage was 0.18 m/sec in patients who underwent shunt surgery versus 0.08 m/sec in patients who did not. For shunt surgery patients, gait velocity increased by 54% from 0.67 m/sec before CSF drainage to 0.96 m/sec 8-12 months after surgery, and 80% of patients had an increase of at least 0.1 m/sec by the first postoperative visit. Evaluation of cognition, urinary symptoms, depression, and functional outcomes also revealed improvement after shunt surgery. Of 193 patients who had undergone shunt surgery, 176 (91%) had no complications and 17 (9%) had 28 complications. Eleven patients (6%) had 14 serious complications that resulted in the need for surgery or an extended hospital stay. The 30-day reoperation rate was 3%. Using criteria recommended by the international iNPH guidelines, the authors found that evaluation and treatment of iNPH are safe and effective. Testing with CSF drainage and treatment with shunt surgery are associated with a high rate of sustained improvement and a low rate of complications for iNPH in the 1st year after shunt surgery. Patients who had undergone shunt surgery for iNPH experienced improvement in gait, cognitive function, bladder symptoms, depression, and functional outcome measures. Gait velocity, which is an easily measured, objective, continuous variable, should be used as a standard outcome measure to test a patient's response to CSF drainage and shunt surgery in iNPH.

Endoscopic third ventriculostomy in previously shunt-treated patients.

Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry. Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized. A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon's report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23-0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication. Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Hydrocephalus surveillance following CSF diversion: a modified Delphi study.

Long-term follow-up is often recommended for patients with hydrocephalus, but the frequency of clinical follow-up, timing and modality of imaging, and duration of surveillance have not been clearly defined. Here, the authors used the modified Delphi method to identify areas of consensus regarding the modality, frequency, and duration of hydrocephalus surveillance following surgical treatment. Pediatric neurosurgeons serving as institutional liaisons to the Hydrocephalus Clinical Research Network (HCRN), or its implementation/quality improvement arm (HCRNq), were invited to participate in this modified Delphi study. Thirty-seven consensus statements were generated and distributed via an anonymous electronic survey, with responses structured as a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). A subsequent, virtual meeting offered the opportunity for open discussion and modification of the statements in an effort to reach consensus (defined as ≥ 80% agreement or disagreement). Nineteen pediatric neurosurgeons participated in the first round, after which 15 statements reached consensus. During the second round, 14 participants met virtually for review and discussion. Some statements were modified and 2 statements were combined, resulting in a total of 36 statements. At the conclusion of the session, consensus was achieved for 17 statements regarding the following: 1) the role of standardization; 2) preferred imaging modalities; 3) postoperative follow-up after shunt surgery (subdivided into immediate postoperative imaging, delayed postoperative imaging, routine clinical surveillance, and routine radiological surveillance); and 4) postoperative follow-up after an endoscopic third ventriculostomy. Consensus could not be achieved for 19 statements. Using the modified Delphi method, 17 consensus statements were developed with respect to both clinical and radiological follow-up after a shunt or endoscopic third ventriculostomy. The frequency, modality, and duration of surveillance were addressed, highlighting areas in which no clear data exist to guide clinical practice. Although further studies are needed to evaluate the clinical utility and cost-effectiveness of hydrocephalus surveillance, the current study provides a framework to guide future efforts to develop standardized clinical protocols for the postoperative surveillance of patients with hydrocephalus. Ultimately, the standardization of hydrocephalus surveillance has the potential to improve patient care as well as optimize the use of healthcare resources.

Endoscopic third ventriculostomy revision after failure of initial endoscopic third ventriculostomy and choroid plexus cauterization.

Primary treatment of hydrocephalus with endoscopic third ventriculostomy (ETV) and choroid plexus cauterization (CPC) is well described in the neurosurgical literature, with wide reported ranges of success and complication rates. The purpose of this study was to describe the safety and efficacy of ETV revision after initial ETV+CPC failure. Prospectively collected data in the Hydrocephalus Clinical Research Network Core Data Project registry were reviewed. Children who underwent ETV+CPC as the initial treatment for hydrocephalus between 2013 and 2019 and in whom the initial ETV+CPC was completed (i.e., not abandoned) were included. Log-rank survival analysis (the primary analysis) was used to compare time to failure (defined as any other surgical treatment for hydrocephalus or death related to hydrocephalus) of initial ETV+CPC versus that of ETV revision by using random-effects modeling to account for the inclusion of patients in both the initial and revision groups. Secondary analysis compared ETV revision to shunt placement after failure of initial ETV+CPC by using the log-rank test, as well as shunt failure after ETV+CPC to that after ETV revision. Cox regression analysis was used to identify predictors of failure among children treated with ETV revision. The authors identified 521 ETV+CPC procedures that met their inclusion criteria. Ninety-one children underwent ETV revision after ETV+CPC failure. ETV revision had a lower 1-year success rate than initial ETV+CPC (29.5% vs 45%, p < 0.001). ETV revision after initial ETV+CPC failure had a lower success rate than shunting (29.5% vs 77.8%, p < 0.001). Shunt survival after initial ETV+CPC failure was not significantly different from shunt survival after ETV revision failure (p = 0.963). Complication rates were similar for all examined surgical procedures (initial ETV+CPC, ETV revision, ventriculoperitoneal shunt [VPS] placement after ETV+CPC, and VPS placement after ETV revision). Only young age was predictive of ETV revision failure (p = 0.02). ETV revision had a significantly lower 1-year success rate than initial ETV+CPC and VPS placement after ETV+CPC. Complication rates were similar for all studied procedures. Younger age, but not time since initial ETV+CPC, was a risk factor for ETV revision failure.

The Hydrocephalus Clinical Research Network quality improvement initiative: the role of antibiotic-impregnated catheters and vancomycin wound irrigation.

Two previous Hydrocephalus Clinical Research Network (HCRN) studies have demonstrated that compliance with a standardized CSF shunt infection protocol reduces shunt infections. In this third iteration, a simplified protocol consisting of 5 steps was implemented. This analysis provides an updated evaluation of protocol compliance and evaluates modifiable shunt infection risk factors. The new simplified protocol was implemented at HCRN centers on November 1, 2016, for all shunt procedures, excluding external ventricular drains, ventricular reservoirs, and subgaleal shunts. Procedures performed through December 31, 2019, were included (38 months). Compliance with the protocol, use of antibiotic-impregnated catheters (AICs), and other variables of interest were collected at the index operation. Outcome events for a minimum of 6 months postoperatively were recorded. The definition of infection was unchanged from the authors' previous report. A total of 4913 procedures were performed at 13 HCRN centers. The overall infection rate was 5.1%. Surgeons were compliant with all 5 steps of the protocol in 79.4% of procedures. The infection rate for the protocol alone was 8.1% and dropped to 4.9% when AICs were added. Multivariate analysis identified having ≥ 2 complex chronic conditions (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.26-2.44, p = 0.01) and a history of prior shunt surgery within 12 weeks (OR 1.84, 95% CI 1.37-2.47, p < 0.01) as independent risk factors for shunt infection. The use of AICs (OR 0.70, 95% CI 0.50-0.97, p = 0.05) and vancomycin irrigation (OR 0.36, 95% CI 0.21-0.62, p < 0.01) were identified as independent factors protective against shunt infection. The authors report the third iteration of their quality improvement protocol to reduce the risk of shunt infection. Compliance with the protocol was high. These updated data suggest that the incorporation of AICs is an important, modifiable infection prevention measure. Vancomycin irrigation was also identified as a protective factor but requires further study to better understand its role in preventing shunt infection.

P.160 Safety and effectiveness of the assessment and treatment of idiopathic normal pressure hydrocephalus (iNPH) in the Adult Hydrocephalus Clinical Research Network (AHCRN)

Background: Idiopathic Normal Pressure Hydrocephalus (iNPH) is a disorder of the elderly with progressive worsening of gait and balance, cognition, and urinary control which requires assessment using criteria recommended by International iNPH guidelines. Methods: Adult Hydrocephalus Clinical Research Network (AHCRN) prospective registry data from 5-centers over a 50-month interval included entry criteria; demographics; comorbidities; examination findings using standard AHCRN gait and neuropsychology assessments; shunt procedures, complications of CSF drainage, complications within 30 days of surgery, and 1-year postoperative follow-up. Results: 547 patients were referred for assessment of suspected-iNPH. 123 patients(21.6%) did not meet clinical criteria to proceed with further testing. 424 patients(74.4%;mean age 76.7 ± 6.0 years;males=269) underwent an LP or lumbar drain, and 193(45.6%) underwent insertion of a ventriculoperitoneal shunt. By 8-12 months after shunt surgery, gait velocity was 0.96±0.35m/s (54% faster than pre-CSF-drainage). Mean MoCA scores increased from 21.0 ± 5.0(median=22.0) at baseline to 22.6±5.5(median=24) 12-months post-surgery. Gait and cognitive improvements were clinically significant. No deaths occurred. 8% of shunt-surgery patients experienced minor complications. The 30-day reoperation rate was 4.1%. Conclusions: This AHCRN study demonstrated that CSF-drainage testing of patients with suspected-iNPH successfully identified those who could undergo CSF-shunt surgery with a high rate of improvement and a low rate of complications.

Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network.

The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure. The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network. The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98-1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages. This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

Impact of ventricle size on neuropsychological outcomes in treated pediatric hydrocephalus: an HCRN prospective cohort study.

In pediatric hydrocephalus, shunts tend to result in smaller postoperative ventricles compared with those following an endoscopic third ventriculostomy (ETV). The impact of the final treated ventricle size on neuropsychological and quality-of-life outcomes is currently undetermined. Therefore, the authors sought to ascertain whether treated ventricle size is associated with neurocognitive and academic outcomes postoperatively. This prospective cohort study included children aged 5 years and older at the first diagnosis of hydrocephalus at 8 Hydrocephalus Clinical Research Network sites from 2011 to 2015. The treated ventricle size, as measured by the frontal and occipital horn ratio (FOR), was compared with 25 neuropsychological tests 6 months postoperatively after adjusting for age, hydrocephalus etiology, and treatment type (ETV vs shunt). Pre- and posttreatment grade point average (GPA), quality-of-life measures (Hydrocephalus Outcome Questionnaire [HOQ]), and a truncated preoperative neuropsychological battery were also compared with the FOR. Overall, 60 children were included with a mean age of 10.8 years; 17% had ≥ 1 comorbidity. Etiologies for hydrocephalus were midbrain lesions (37%), aqueductal stenosis (22%), posterior fossa tumors (13%), and supratentorial tumors (12%). ETV (78%) was more commonly used than shunting (22%). Of the 25 neuropsychological tests, including full-scale IQ (q = 0.77), 23 tests showed no univariable association with postoperative ventricle size. Verbal learning delayed recall (p = 0.006, q = 0.118) and visual spatial judgment (p = 0.006, q = 0.118) were negatively associated with larger ventricles and remained significant after multivariate adjustment for age, etiology, and procedure type. However, neither delayed verbal learning (p = 0.40) nor visual spatial judgment (p = 0.22) was associated with ventricle size change with surgery. No associations were found between postoperative ventricle size and either GPA or the HOQ. Minimal associations were found between the treated ventricle size and neuropsychological, academic, or quality-of-life outcomes for pediatric patients in this comprehensive, multicenter study that encompassed heterogeneous hydrocephalus etiologies.

Cognitive and gait outcomes after primary endoscopic third ventriculostomy in adults with chronic obstructive hydrocephalus.

The object of this study was to determine the short- and long-term efficacy of primary endoscopic third ventriculostomy (ETV) on cognition and gait in adults with chronic obstructive hydrocephalus. Patients were prospectively accrued through the Adult Hydrocephalus Clinical Research Network patient registry. Patients with previously untreated congenital or acquired obstructive hydrocephalus were included in this study. Gait velocity was assessed using a 10-m walk test. Global cognition was assessed with the Montreal Cognitive Assessment (MoCA). Only patients with documented pre- and post-ETV gait analysis and/or pre- and post-ETV MoCA were included. A total of 74 patients had undergone primary ETV, 42 of whom were analyzed. The remaining 32 patients were excluded, as they could not complete both pre- and post-ETV assessments. The mean age of the 42 patients, 19 (45.2%) of whom were female, was 51.9 ± 17.1 years (range 19-79 years). Most patients were White (37 [88.1%]), and the remainder were Asian. Surgical complications were minor. Congenital etiologies occurred in 31 patients (73.8%), with aqueductal stenosis in 23 of those patients (54.8%). The remaining 11 patients (26.2%) had acquired cases. The gait short-term follow-up cohort (mean 4.7 ± 4.1 months, 35 patients) had a baseline median gait velocity of 0.9 m/sec (IQR 0.7-1.3 m/sec) and a post-ETV median velocity of 1.3 m/sec (IQR 1.1-1.4 m/sec). Gait velocity significantly improved post-ETV with a median within-patient change of 0.3 m/sec (IQR 0.0-0.6 m/sec, p < 0.001). Gait velocity improvements were sustained in the long term (mean 14 ± 2.8 months, 12 patients) with a baseline median velocity of 0.7 m/sec (IQR 0.6-1.3 m/sec), post-ETV median of 1.3 m/sec (IQR 1.1-1.7 m/sec), and median within-patient change of 0.4 m/sec (IQR 0.2-0.6 m/sec, p < 0.001). The cognitive short-term follow-up cohort (mean 4.6 ± 4.0 months, 38 patients) had a baseline median MoCA total score (MoCA TS) of 24/30 (IQR 23-27) that improved to 26/30 (IQR 24-28) post-ETV. The median within-patient change was +1 point (IQR 0-2 points, p < 0.001). However, this change is not clinically significant. The cognitive long-term follow-up cohort (mean 14 ± 3.1 months, 15 patients) had a baseline median MoCA TS of 23/30 (IQR 22-27), which improved to 26/30 (IQR 25-28) post-ETV. The median within-patient change was +2 points (IQR 1-3 points, p = 0.007), which is both statistically and clinically significant. Primary ETV can safely improve symptoms of gait and cognitive dysfunction in adults with chronic obstructive hydrocephalus. Gait velocity and global cognition were significantly improved, and the worsening of either was rare following ETV.

Hydrocephalus surveillance following shunt placement or endoscopic third ventriculostomy: a survey of surgeons in the Hydrocephalus Clinical Research Networks.

Late failure is a well-documented complication of cerebrospinal fluid shunt placement and, less commonly, endoscopic third ventriculostomy (ETV). However, standards regarding the frequency of clinical and radiological follow-up in these patients have not been defined. Here, the authors report on their survey of surgeons at sites for the Hydrocephalus Clinical Research Network (HCRN) or its implementation/quality improvement arm (HCRNq) to provide a cross-sectional overview of practice patterns. A 24-question survey was developed using the Research Electronic Data Capture (REDCap) platform and was distributed to the 138 pediatric neurosurgeons across 39 centers who participate in the HCRN or HCRNq. Survey questions were organized into three sections: 1) Demographics (5 questions), 2) Shunt Surveillance (12 questions), and 3) ETV Surveillance (7 questions). A total of 122 complete responses were obtained, for an overall response rate of 88%. The majority of respondents have been in practice for more than 10 years (58%) and exclusively treat pediatric patients (79%). Most respondents consider hydrocephalus to have stabilized 1 month (21%) or 3 months (39%) after shunt surgery, and once stability is achieved, 72% then ask patients to return for routine clinical follow-up annually. Overall, 83% recommend lifelong clinical follow-up after shunt placement. Additionally, 75% obtain routine imaging studies in asymptomatic patients, although the specific imaging modality and frequency of imaging vary. The management of an asymptomatic increase in ventricle size or an asymptomatic catheter fracture also varies widely. Many respondents believe that hydrocephalus takes longer to stabilize after ETV than after shunt placement, reporting that they consider hydrocephalus to have stabilized 3 (28%), 6 (33%), or 12 (28%) months after an ETV. Although 68% of respondents have patients return annually for routine clinical follow-up after an ETV, only 56% recommend lifelong follow-up. The proportion of respondents who perform lifelong follow-up increases with greater practice experience (p = 0.01). Overall, 67% of respondents obtain routine imaging studies in asymptomatic patients after an ETV, with "rapid" MRI the study of choice for most respondents. While there is a general consensus among pediatric neurosurgeons across North America that hydrocephalus patients should have long-term follow-up after shunt placement, radiological surveillance is characterized by considerable variety, as is follow-up after an ETV. Future work should focus on evaluating whether any one of these surveillance protocols is associated with improved outcomes.

Treatment strategies for hydrocephalus related to Dandy-Walker syndrome: evaluating procedure selection and success within the Hydrocephalus Clinical Research Network.

Treating Dandy-Walker syndrome-related hydrocephalus (DWSH) involves either a CSF shunt-based or endoscopic third ventriculostomy (ETV)-based procedure. However, comparative investigations are lacking. This study aimed to compare shunt-based and ETV-based treatment strategies utilizing archival data from the Hydrocephalus Clinical Research Network (HCRN) registry. A retrospective review of prospectively collected and maintained data on children with DWSH, available from the HCRN registry (14 sites, 2008-2018), was performed. The primary outcome was revision-free survival of the initial surgical intervention. The primary exposure was either shunt-based (i.e., cystoperitoneal shunt [CPS], ventriculoperitoneal shunt [VPS], and/or dual-compartment) or ETV-based (i.e., ETV alone or with choroid plexus cauterization [CPC]) initial surgical treatment. Primary analysis included multivariable Cox proportional hazards models. Of 8400 HCRN patients, 151 (1.8%) had DWSH. Among these, the 102 patients who underwent shunt placement (79 VPSs, 16 CPSs, 3 other, and 4 multiple proximal catheter) were younger (6.6 vs 18.8 months, p < 0.001) and more frequently had 1 or more comorbidities (37.3% vs 14.3%, p = 0.005) than the 49 ETV-treated children (28 ETV-CPC). Fifty percent of the shunt-based and 51% of the ETV-based treatments failed. Notably, 100% (4/4) of the dual-compartment shunts failed. Adjusting for age, baseline ventricular size, and comorbidities, ETV-based treatment was not significantly associated with earlier failure compared with shunt-based treatment (HR for failure 1.32, 95% CI 0.77-2.26; p = 0.321). Complication rates were low: 4.9% and 6.1% (p = 0.715) for shunt- and ETV-based procedures, respectively. There was no difference in survival between ETV-CPC- and ETV-based treatment when adjusting for age (HR for failure 0.86, 95% CI 0.29-2.55, p = 0.783). In this North American, multicenter, prospective database review, shunt-based and ETV-based primary treatment strategies of DWSH appear similarly durable. Pediatric neurosurgeons can reasonably consider ETV-based initial treatment given the similar durability and the low complication rate. However, given the observational nature of this study, the treating surgeon might need to consider subgroups that were too small for a separate analysis. Very young children with comorbidities were more commonly treated with shunts, and older children with fewer comorbidities were offered ETV-based treatment. Future studies may determine preoperative characteristics associated with ETV treatment success in this population.