Programmable Shunt Valves for Pediatric Hydrocephalus: 22-Year Experience from a Singapore Children’s Hospital

(1) Background: pediatric hydrocephalus is a challenging condition. Programmable shunt valves (PSV) have been increasingly used. This study is undertaken to firstly, to objectively evaluate the efficacy of PSV as a treatment modality for pediatric hydrocephalus; and next, review its associated patient outcomes at our institution. Secondary objectives include the assessment of our indications for PSV, and corroboration of our results with published literature. (2) Methods: this is an ethics-approved, retrospective study. Variables of interest include age, gender, hydrocephalus etiology, shunt failure rates and incidence of adjustments made per PSV. Data including shunt failure, implant survival, and utility comparisons between PSV types are subjected to statistical analyses. (3) Results: in this case, 51 patients with PSV are identified for this study, with 32 index and 19 revision shunts. There are 3 cases of shunt failure (6%). The mean number of adjustments per PSV is 1.82 times and the mean number of adjustments made per PSV is significantly lower for MEDTRONIC™ Strata PSVs compared with others (p = 0.031). Next, PSV patients that are adjusted more frequently include cases of shunt revisions, PSVs inserted due to CSF over-drainage and tumor-related hydrocephalus. (4) Conclusion: we describe our institutional experience of PSV use in pediatric hydrocephalus and its advantages in a subset of patients whose opening pressures are uncertain and evolving.

P.148 Children and teenagers with hydrocephalus: Are narrowed dural sinuses better predictors of shunt-failure than ventriculomegaly?

Background: Intracranial hypertension secondary to shunt-failure is a feared complication requiring cross-sectional imaging for diagnosis. We compared dural sinus narrowing and ventriculomegaly as predictors of shunt-failure. Methods: 60 head MRIs and 60 MR venographies of hydrocephalus patients age 0-18 years (n=25) were analyzed. MRI studies were included when f/u clinical data combined with intra-operative findings proved shunt-failure (positive Gold standard) or when MRI was available when the child was well (negative Gold standard). The absence or presence of concerning hydrocephalus was diagnosed. On MRV, the major dural sinuses were independently analyzed with respect to >50% narrowing, suggesting compression by increased CSF pressure. Ventriculomegaly and significant dural sinus narrowing was correlated to the presence/absence of shunt failure as per Gold standard. Results: Sinus narrowing substantially correlated with proven shunt-failure (Cohen’s kappa test 0.635/p<=0.00001 as per Fisher exact test) while ventriculomegaly correlated poorly (0.258/p=0.0751). Sensitivity/specificity was 0.69/0.92 for sinus narrowing and 0.43/0.81 for ventriculomegaly. Conclusions: In this patient cohort, dural sinus narrowing more reliably predicted shunt-failure compared to ventriculomegaly.

P.207 Reducing the risks of proximal and distal shunt failure in adult hydrocephalus: A Shunt Outcomes Quality Improvement (ShOut-QI) Study

Background: Ventriculoperitoneal (VP) shunt failures in adult patients are common and subject patients to multiple surgeries and a decreased quality of life. A prospective cohort Shunt Outcomes Quality Improvement (ShOut-QI) initiative was implemented to reduce shunt failure incidence through neuronavigation-assisted proximal catheter insertion and laparoscopy-guided distal catheter anchoring over the liver dome to drain CSF away from the omentum. Methods: “Pre-ShOut” and “Post-ShOut” groups of patients included those with and without neuronavigation/laparoscopy, respectively for insertion of a new VP shunt. The primary outcome was shunt failure which was defined as any return to surgery for shunt revision as determined with a standardized clinical and radiology follow-up protocol. Results: 244 patients (97 Pre-ShOut, 147 Post-ShOut), mean age 73 years, were enrolled over a 7-year interval and observed for a mean duration of 4 years after shunt insertion. Neuronavigation improved proximal catheter placement accuracy by 20% (p<.001), and shunt failure occurred in 57% vs 23% in the Pre-ShOut and Post-ShOut groups, respectively (p=.008), representing a 53% relative risk reduction in the incidence of shunt failure. Conclusions: Adult shunt failure incidence may be significantly reduced by improving the accuracy of proximal catheter placement with neuronavigation and reducing the risk of distal catheter failure with laparoscopic-guided placement.

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

OBJECTIVE The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Factors associated with early shunt revision within 30 days: analyses from the National Surgical Quality Improvement Program

OBJECTIVE CSF shunt insertion is the most commonly performed neurosurgical procedure for pediatric patients with hydrocephalus, and complications including infections and catheter obstruction are common. The rate of readmission in the first 30 days after surgery has been used across surgical disciplines to determine healthcare quality. In the current study, the authors sought to assess factors associated with early shunt revision within 30 days using real-world data. METHODS Targeted shunt data set participant user files of the National Surgical Quality Improvement Program (NSQIP) from 2016 to 2019 were queried for patients undergoing a shunt procedure. A multivariable logistic regression model was performed to assess the impact of demographics, etiologies, comorbidities, congenital malformations, and shunt adjuncts on shunt revision within 30 days, as well as shunt revision due to infection within 30 days. RESULTS A total of 3919 primary pediatric shunt insertions were identified in the NSQIP database, with a mean (± SD) patient age of 26.3 ± 51.6 months. There were a total of 285 (7.3%) unplanned shunt revisions within 30 days, with a mean duration of 14.9 ± 8.5 days to first intervention. The most common reason for intervention was mechanical shunt failure (32.6% of revision, 2.4% overall, n = 93), followed by infection (31.2% of all interventions, 2.3% overall, n = 89) and wound disruption or CSF leak (22.1% of all interventions, 1.6% overall, n = 63). Patients younger than 6 months of age had the highest overall unplanned 30-day revision rate (8.5%, 203/2402) as well as the highest 30-day shunt infection rate (3%, 72/2402). Patients who required a revision were also more likely to have a cardiac risk factor (34.7%, n = 99, vs 29.2%, n = 1061; p = 0.048). Multivariable logistic regression revealed that compared to patients 9–18 years old, those aged 2–9 years had significantly lower odds of repeat shunt intervention (p = 0.047), while certain etiologies including congenital hydrocephalus (p = 0.0127), intraventricular hemorrhage (IVH) of prematurity (p = 0.0173), neoplasm (p = 0.0005), infection (p = 0.0004), and syndromic etiology (p = 0.0136), as well as presence of ostomy (p = 0.0095), were associated with higher odds of repeat intervention. For shunt infection, IVH of prematurity was found to be associated with significantly higher odds (p = 0.0427) of shunt infection within 30 days, while use of intraventricular antibiotics was associated with significantly lower odds (p = 0.0085). CONCLUSIONS In this study of outcomes after pediatric shunt placement using a nationally derived cohort, early shunt failure and infection within 30 days were found to remain as considerable risks. The analysis of this national surgical quality registry confirms that, in accordance with other multicenter studies, hydrocephalus etiology, age, and presence of ostomy are important predictors of the need for early shunt revision. IVH of prematurity is associated with early infections while intraventricular antibiotics may be protective. These findings could be used for benchmarking in hospital efforts to improve quality of care for pediatric patients with hydrocephalus.

Reducing the risks of proximal and distal shunt failure in adult hydrocephalus: a shunt outcomes quality improvement study

OBJECTIVE Patient outcomes of ventriculoperitoneal (VP) shunt surgery, the mainstay treatment for hydrocephalus in adults, are poor because of high shunt failure rates. The use of neuronavigation or laparoscopy can reduce the risks of proximal or distal shunt catheter failure, respectively, but has less independent effect on overall shunt failures. No adult studies to date have combined both approaches in the setting of a shunt infection prevention protocol to reduce shunt failure. The goal of this study was to determine whether combining neuronavigation and laparoscopy with a shunt infection prevention strategy would reduce the incidence of shunt failures in adult hydrocephalic patients. METHODS Adult patients (age ≥ 18 years) undergoing VP shunt surgery at a tertiary care institution prior to (pre–Shunt Outcomes [ShOut]) and after (post-ShOut) the start of a prospective continuous quality improvement (QI) study were compared. Pre-ShOut patients had their proximal and distal catheters placed under conventional freehand approaches. Post-ShOut patients had their shunts inserted with neuronavigational and laparoscopy assistance in placing the distal catheter in the perihepatic space (falciform technique). A shunt infection reduction protocol had been instituted 1.5 years prior to the start of the QI initiative. The primary outcome of interest was the incidence of shunt failure (including infection) confirmed by standardized criteria indicating shunt revision surgery. RESULTS There were 244 (115 pre-ShOut and 129 post-ShOut) patients observed over 7 years. With a background of shunt infection prophylaxis, combined neuronavigation and laparoscopy was associated with a reduction in overall shunt failure rates from 37% to 14%, 45% to 22%, and 51% to 29% at 1, 2, and 3 years, respectively (HR 0.44, p < 0.001). Shunt infection rates decreased from 8% in the pre-ShOut group to 0% in the post-ShOut group. There were no proximal catheter failures in the post-ShOut group. The 2-year rates of distal catheter failure were 42% versus 20% in the pre- and post-ShOut groups, respectively (p < 0.001). CONCLUSIONS Introducing a shunt infection prevention protocol, placing the proximal catheter under neuronavigation, and placing the peritoneal catheter in the perihepatic space by using the falciform technique led to decreased rates of infection, distal shunt failure, and overall shunt failure.

Readmissions after ventricular shunting in pediatric patients with hydrocephalus: a Nationwide Readmissions Database analysis

OBJECTIVE Cerebrospinal fluid diversion via ventricular shunting is a common surgical treatment for hydrocephalus in the pediatric population. No longitudinal follow-up data for a multistate population-based cohort of pediatric patients undergoing ventricular shunting in the United States have been published. In the current review of a nationwide population-based data set, the authors aimed to assess rates of shunt failure and hospital readmission in pediatric patients undergoing new ventricular shunt placement. They also review patient- and hospital-level factors associated with shunt failure and readmission. METHODS Included in this study was a population-based sample of pediatric patients with hydrocephalus who, in 2010–2014, had undergone new ventricular shunt placement and had sufficient follow-up, as recorded in the Nationwide Readmissions Database. The authors analyzed the rate of revision within 6 months, readmission rates at 30 and 90 days, and potential factors associated with shunt failure including patient- and hospital-level variables and type of hydrocephalus. RESULTS A total of 3520 pediatric patients had undergone initial ventriculoperitoneal shunt placement for hydrocephalus at an index admission. Twenty percent of these patients underwent shunt revision within 6 months. The median time to revision was 44.5 days. Eighteen percent of the patients were readmitted within 30 days and 31% were readmitted within 90 days. Different-hospital readmissions were rare, occurring in ≤ 6% of readmissions. Increased hospital volume was not protective against readmission or shunt revision. Patients with grade 3 or 4 intraventricular hemorrhage were more likely to have shunt malfunctions. Patients who had private insurance and who were treated at a large hospital were less likely to be readmitted. CONCLUSIONS In a nationwide, population-based database with longitudinal follow-up, shunt failure and readmission were common. Although patient and hospital factors were associated with readmission and shunt failure, system-wide phenomena such as insufficient centralization of care and fragmentation of care were not observed. Efforts to reduce readmissions in pediatric patients undergoing ventricular shunt procedures should focus on coordinating care in patients with complex neurological diseases and on reducing healthcare disparities associated with readmission.