Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 5: Effect of valve type on cerebrospinal fluid shunt efficacy

Does Valve Design Affect the Tensile Strength of Ventriculoperitoneal Shunts?

BACKGROUND AND OBJECTIVES

The most common treatment for hydrocephalus is ventriculoperitoneal (VP) shunting, which is problematic as shunts are prone to failure. Shunt disconnections account for a minority (8%-15%) of VP shunt failures but could be reduced through better shunt design. A better understanding of the mechanical properties of VP shunts would help explain why shunt disconnections occur. The objective of this study was to determine if the tensile properties of VP shunts differ by design.

METHODS

Linear tensile testing was conducted on 5 different valve designs (Codman Certas Plus Programmable Valve, Medtronic Delta, Integra Orbis Sigma Valve II, Medtronic PS Medical, Medtronic Strata Adjustable Valve) at both the proximal and distal ends to determine the maximum load which could be applied to different shunt designs. Each valve was progressively subjected to increasing force until the catheter disconnected from the valve, the catheter fractured, or our maximum testing limits were reached.

RESULTS

Catheters disconnected or fractured during testing with all valves. The maximum load resisted during tensile testing for similar locations in all valve designs were found to be statistically similar to one another. Only the PS Medical and Orbis Sigma II valves showed an increased maximum load at the distal end compared with the proximal end within the same device.

CONCLUSION

No single valve design was superior at preventing disconnections in VP shunts. Shunt disconnections remain a concerning problem as VP shunts are the gold standard for combating hydrocephalus.

Development of shunt valves used for treating hydrocephalus: comparison with endoscopy treatment

The pathophysiology of hydrocephalus is not clearly defined. Thus, treatment will remain empirical until a fuller understanding of the various forms of hydrocephalus is achieved. Valve-controlled shunting has been the mainstay of therapy since the late 1950s. Initially, shunting occurred from the ventricular system to the atrium. In the 1970s, VA shunts were replaced by ventriculoperitoneal shunts as the primary location for the distal end. Multiple types of one-way valve systems have been developed in the pursuit of draining the appropriate amount of CSF that avoids either overdrainage or underdrainage while preserving normal brain development and cognition. These valves are reviewed and compared as to their function. Other locations for the distal end of the shunting system are reviewed to include pleural space and gallbladder. The lumbar subarachnoid space as the proximal location for a shunt is also reviewed. The only other surgical alternative for treating hydrocephalus is endoscopic third ventriculostomy. Since 2000, approximately 50% of children with hydrocephalus have been shown to be candidates for ETV. The benefits are the lack of need for an artificial shunt system and thus lower rates of infection and over time fewer reoperations. Future progress is dependent on improved shunt valve systems that are affordable worldwide and ready availability of ETV in developing countries. Anatomic and molecular causes of hydrocephalus need to be defined so that medications or genetic modifications become available for potential cure of hydrocephalus.

Factors affecting ventriculoperitoneal shunt revision: a post hoc analysis of the British Antibiotic and Silver Impregnated Catheter Shunt multicenter randomized controlled trial

OBJECTIVE

The British Antibiotic and Silver Impregnated Catheter Shunt (BASICS) trial established level I evidence of the superiority of antibiotic-impregnated catheters in the prevention of infection of newly implanted ventriculoperitoneal shunts (VPSs). A wealth of patient, shunt, and surgery-specific data were collected from trial participants beyond that of the prespecified trial objectives.

METHODS

This post hoc analysis of the BASICS survival data explores the impact of patient age, hydrocephalus etiology, catheter type, valve type, and previous external ventricular drain on the risk of infection or mechanical failure. Time to failure was analyzed using Fine and Gray survival regression models for competing risk.

RESULTS

Among 1594 participants, 75 patients underwent revision for infection and 323 for mechanical failure. Multivariable analysis demonstrated an increased risk of shunt infection associated with patient ages < 1 month (subdistribution hazard ratio [sHR] 4.48, 95% CI 2.06-9.72; p < 0.001) and 1 month to < 1 year (sHR 2.67, 95% CI 1.27-5.59; p = 0.009), as well as for adults with posthemorrhagic hydrocephalus (sHR 2.75, 95% CI 1.21-6.26; p = 0.016). Age ≥ 65 years was found to be independently associated with reduced infection risk (sHR 0.26, 95% CI 0.10-0.69; p = 0.007). Antibiotic-impregnated catheter use was also associated with reduced infection risk (sHR 0.43, 95% CI 0.22-0.84; p = 0.014). Independent risk factors predisposing to mechanical failure were age < 1 month (sHR 1.51, 95% CI 1.03-2.21; p = 0.032) and 1 month to < 1 year (sHR 1.31, 95% CI 0.95-1.81; p = 0.046). Age ≥ 65 years was demonstrated to be the only independent protective factor against mechanical failure risk (sHR 0.64, 95% CI 0.40-0.94; p = 0.024).

CONCLUSIONS

Age is the predominant risk for VPS revision for infection and/or mechanical failure, with neonates and infants being the most vulnerable.

Revision rates of flow- versus pressure-regulated ventricular shunt valves for the treatment of hydrocephalus in neonates following germinal matrix haemorrhage-a retrospective review

PURPOSE

Neonates with ventricular shunts inserted for hydrocephalus following germinal matrix haemorrhage (GMH) have high rates of shunt revision. The shunt valve plays a key role in regulating the function of the shunt. In this study, we aim to determine if the choice of flow-regulated or pressure-regulated valve used in the initial implantation of a shunt affects the rate of shunt revision.

METHODS

A retrospective cohort comparison study was performed on 34 neonates with hydrocephalus following GMH who underwent placement of a ventricular shunt at the Queensland Children's Hospital from November 2014 to June 2020. The primary outcome examined was the need for revision or replacement of the ventricular shunt after successful initial placement within 2 years of implantation. The secondary outcome examined was the survival time of the shunt.

RESULTS

16 patients had placement of a flow-regulated valve, and 18 patients had placement of a pressure-regulated valve. 14 (87.5%) patients with flow-regulated valves required replacement during the follow-up period. 2 (18.18%) patients with a fixed pressure regulated underwent revision, while 2 (28.57%) programmable pressure-regulated shunts required revision. Patients that had a flow-regulated valve had a statistically significant higher rate of revision compared to those who had a pressure-regulated valve, (87.5% flow vs 22.22% pressure) with a P-value of < 0.001. Valve obstruction was also more common in patients with flow-regulated valves than pressure-regulated valves (4 vs 0) with a P-value of 0.010. Overall mean median survival time was 22.06 months, shunts with flow-regulated valves had a shorter median survival time of 3.19 months compared with over 24 months for pressure-regulated valves with a P-value of < 0.001.

CONCLUSION

Our study suggests that the initial implantation of flow-regulated valves may carry an increased total rate of shunt revision and valve obstruction within the first 2 years following implantation compared to pressure-regulated valves in patients with hydrocephalus following GMH.

An eye on the future for defeating hydrocephalus, ciliary dyskinesia-related hydrocephalus: review article

Congenital hydrocephalus affects approximately one in 1000 newborn children and is fatal in approximately 50% of untreated cases. The currently known management protocols usually necessitate multiple interventions and long-term use of healthcare resources due to a relatively high incidence of complications, and many of them mostly provide a treatment of the effect rather than the cause of cerebrospinal fluid flow reduction or outflow obstruction. Future studies discussing etiology specific hydrocephalus alternative treatments are needed. We systematically reviewed the available literature on the effect of ciliary abnormality on congenital hydrocephalus pathogenesis, to open a discussion on the feasibility of factoring ciliary abnormality in future research on hydrocephalus treatment modalities. Although there are different forms of ciliopathies, we focused in this review on primary ciliary dyskinesia. There is growing evidence of association of other ciliary syndromes and hydrocephalus, such as the reduced generation of multiple motile cilia, which is distinct from primary ciliary dyskinesia. Data for this review were identified by searching PubMed using the search terms 'hydrocephalus,' 'Kartagener syndrome,' 'primary ciliary dyskinesia,' and 'immotile cilia syndrome.' Only articles published in English and reporting human patients were included. Seven studies met our inclusion criteria, reporting 12 cases of hydrocephalus associated with primary ciliary dyskinesia. The patients had variable clinical presentations, genetic backgrounds, and ciliary defects. The ependymal water propelling cilia differ in structure and function from the mucus propelling cilia, and there is a possibility of isolated non-syndromic ependymal ciliopathy causing only hydrocephalus with growing evidence in the literature for the association ependymal ciliary abnormality and hydrocephalus. Abdominal and thoracic situs in children with hydrocephalus can be evaluated, and secondary damage of ependymal cilia causing hydrocephalus in cases with generalized ciliary abnormality can be considered.

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.

Shunt technology for infants and a lifetime

The use of cerebrospinal fluid (CSF) shunts remains a fundamental therapeutic modality in the management of hydrocephalus. Nowadays, neurosurgeons have an arsenal of different shunt technologies on their hands, with several companies producing many different configurations of them. The greatest difficulty of treating a child with hydrocephalus is to deal with a brain that will enormously change its size and hydrodynamic conditions and a body that will multiply its height and weight in a short time. Detailed knowledge of the hydrodynamic properties of shunts is mandatory for any neurosurgeon and much more for those taking care of pediatric patients. It is necessary to know that these properties of the valve may influence the evolution of the patient after shunting and it is recognized that a patient physiology-specific valve selection may yield better outcomes and decrease complications. This article provides a summary of the most common available CSF valves and overdrainage control devices, their technology, and possible combinations. The objective is to offer a quick overview of the armamentarium to facilitate the recognition of the implanted device and improve the selection of the most suitable valve for each patient.

Surgical treatment of post-infectious hydrocephalus in infants

The management of post-infective hydrocephalus in infants remains a challenging task for the pediatric neurosurgeon. The decision-making curve is often complex in that appropriate temporizing measures need to be implemented to properly clear any infection within the CSF before any decision can be made regarding a permanent solution. The etiology differs at varying stages of neonatal development, and the weight of the child, skin fragility, and relevant surgical treatment options are often important limiting factors. Deciding on the optimal treatment option involves assessing the etiology, age, and clinical and radiological features of the individual case and selecting the most appropriate surgical option.

Survival status and predictors of mortality among children who underwent ventriculoperitoneal shunt surgery at public hospitals in Addis Ababa, Ethiopia

Background: Despite the increase in ventriculoperitoneal shunt surgeries performed for children with hydrocephalus, the potential complications and survival of patients after the procedure remains the major challenge for both clinical and public health aspects. This study intends to assess the survival status and scrutinize the predictive factors of mortality among children after a ventriculoperitoneal shunt.Methods: A retrospective cohort study was employed by reviewing charts of 337 systematically selected children who have undergone a ventriculoperitoneal shunt from 2016 to 2018 in Addis Ababa. The extraction tool was used for data collection, Epi-data version 4.4.2 for data entry, and Stata version-14 for cleaning and analysis. Kaplan-Meier curve, log-rank test, and life table were used to describe the data. Cox proportional hazard regression model was used for analysis. Any variable at p < 0.25 in the bi-variable analysis was fitted to multivariate analysis, and significance was declared at p ≤ 0.05. Then, AHR with 95% CI was used to report the association and test the statistical significance. Finally, texts and tables were used to present the results.Results and Conclusion: The incidence rate of mortality was 58.4 per 1000 child-months of observation with a median survival time of 12 months (95%CI: 9.04-14.96). Communicative hydrocephalus (AHR: 1.99, 95% CI: 1.18-3.36), post-traumatic brain injury (AHR: 7.43, 95% CI: 3.21-16.88), emergency surgery (AHR: 1.86, 95% CI: 1.17-3.13) as well as revised shunt procedure (AHR: 8.01, 95% CI: 6.12-13.43) were independent predictors of death. Besides, sunset eye (ARH: 2.01; 95% CI: 1.17-3.47), rapidly increased head size (ARH: 2.05, 95% CI: 1.14-3.37), prolonged antibiotics treatment (AHR: 2.46, 95% CI: 1.82-7.37), and gram-negative infections (AHR: 1.95, 95% CI: 1.60-12.64) were also significantly associated. Hence, health professionals ought to give special attention to patients with identified predictors.

CSF Dynamics for Shunt Prognostication and Revision in Normal Pressure Hydrocephalus

BACKGROUND

Despite the quantitative information derived from testing of the CSF circulation, there is still no consensus on what the best approach could be in defining criteria for shunting and predicting response to CSF diversion in normal pressure hydrocephalus (NPH).

OBJECTIVE

We aimed to review the lessons learned from assessment of CSF dynamics in our center and summarize our findings to date. We have focused on reporting the objective perspective of CSF dynamics testing, without further inferences to individual patient management.

DISCUSSION

No single parameter from the CSF infusion study has so far been able to serve as an unquestionable outcome predictor. Resistance to CSF outflow (Rout) is an important biological marker of CSF circulation. It should not, however, be used as a single predictor for improvement after shunting. Testing of CSF dynamics provides information on hydrodynamic properties of the cerebrospinal compartment: the system which is being modified by a shunt. Our experience of nearly 30 years of studying CSF dynamics in patients requiring shunting and/or shunt revision, combined with all the recent progress made in producing evidence on the clinical utility of CSF dynamics, has led to reconsidering the relationship between CSF circulation testing and clinical improvement.

CONCLUSIONS

Despite many open questions and limitations, testing of CSF dynamics provides unique perspectives for the clinician. We have found value in understanding shunt function and potentially shunt response through shunt testing in vivo. In the absence of infusion tests, further methods that provide a clear description of the pre and post-shunting CSF circulation, and potentially cerebral blood flow, should be developed and adapted to the bed-space.

Interactions between programmable shunt valves and magnetically controlled growing rods for scoliosis

OBJECTIVE

Although the advent of magnetic growing rod technology for scoliosis has provided a means to bypass multiple hardware lengthening operations, it is important to be aware that many of these same patients have a codiagnosis of hydrocephalus with magnet-sensitive programmable ventricular shunts. As the magnetic distraction of scoliosis rods has not previously been described to affect the shunt valve setting, the authors conducted an investigation to characterize the interaction between the two devices.

METHODS

In this ex vivo study, the authors carried out 360 encounters between four different shunt valve types at varying distances from the magnetic external remote control (ERC) used to distract the growing rods. Valve settings were examined before and after every interaction with the remote control to determine if there was a change in the setting.

RESULTS

The Medtronic Strata and Codman Hakim valves were found to have setting changes at distances of 3 and 6 inches but not at 12 inches. The Aesculap proGAV and Codman Certas valves, typically described as MRI-resistant, did not have any setting changes due to the magnetic ERC regardless of distance.

CONCLUSIONS

Although it is not necessary to check a shunt valve after every magnetic distraction of scoliosis growing rods, if there is concern that the magnetic ERC may have been within 12 inches (30 cm) of a programmable ventricular shunt valve, the valve should be checked at the bedside with a programmer or with a skull radiograph along with postdistraction scoliosis radiographs.

Inflammation and obstruction of distal catheter slits in ventriculoperitoneal shunts: likely role of graphite

OBJECTIVE

Tissue reactions that contribute to obstruction of peritoneal catheters in ventriculoperitoneal shunt systems are not well characterized. Several recent rapid obstructions in children prompted a retrospective quality assurance review.

METHODS

The authors conducted a detailed investigation of 22 surgically explanted peritoneal shunt catheters and 8 autopsy cases with documented distal shunt obstruction. Patients' medical histories were reviewed, and the catheters and/or tissues were subjected to conventional histological and immunohistochemical evaluations. In addition, 3 cases were subjected to electron microscopic examination including elemental analysis.

RESULTS

The majority of symptomatic obstructions were associated with distal slit catheters (17 slit, 3 open-end, and 2 unknown type). Among the autopsy cases, deaths were attributed to shunt failure in 2 cases of slit catheter obstruction, 1 case of open-end catheter obstruction, and 1 case of catheter withdrawal from the peritoneal cavity. The early tissue response consisted of a predominantly T lymphocyte accumulation with phagocytosis of graphite particles by macrophages. This is associated with proliferation of fibroblasts, mesothelial cells, and blood vessels, which can grow through the slits and occlude the catheter lumen. As the inflammation subsides after approximately 1 year, the tissue plug becomes collagenized and calcified.

CONCLUSIONS

This study, supported by experimental literature in other organ systems, indicates that graphite used to coat the slit openings of distal catheters from ventriculoperitoneal shunts likely predisposes to obstruction. Neurosurgeons and manufacturers should consider the potential negative consequences of this shunt design. The authors concur with previous recommendations that slit-valve distal catheters should not be used for ventriculoperitoneal shunting unless they can be proven safe and efficacious in a controlled trial.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Treatment of Pediatric Hydrocephalus: Update of the 2014 Guidelines

BACKGROUND

The Congress of Neurological Surgeons reviews its guidelines according to the Institute of Medicine's recommended best practice of reviewing guidelines every 5 yrs. The authors performed a planned 5-yr review of the medical literature used to develop the “Pediatric hydrocephalus: systematic literature review and evidence-based guidelines” and determined the need for an update to the original guideline based on new available evidence.

OBJECTIVE

To perform an update to include the current medical literature for the “Pediatric hydrocephalus: systematic literature review and evidence-based guidelines”, originally published in 2014.

METHODS

The Guidelines Task Force used the search terms and strategies consistent with the original guidelines to search PubMed and Cochrane Central for relevant literature published between March 2012 and November 2019. The same inclusion/exclusion criteria were also used to screen abstracts and to perform the full-text review. Full text articles were then reviewed and when appropriate, included as evidence and recommendations were added or changed accordingly.

RESULTS

A total of 41 studies yielded by the updated search met inclusion criteria and were included in this update.

CONCLUSION

New literature resulting from the update yielded a new recommendation in Part 2, which states that neuro-endoscopic lavage is a feasible and safe option for the removal of intraventricular clots and may lower the rate of shunt placement (Level III). Additionally a recommendation in part 7 of the guideline now states that antibiotic-impregnated shunt tubing reduces the risk of shunt infection compared with conventional silicone hardware and should be used for children who require placement of a shunt (Level I). &lt;https://www.cns.org/guidelines/browse-guidelines-detail/pediatric-hydrocephalus-guideline&gt;

When Opposites Attract: Pediatric Cochlear Implantation in the Setting of Cerebrospinal Fluid Shunts

OBJECTIVE

The Food and Drug Administration (FDA) has recently raised concern regarding the safety of cochlear implantation in the setting of programmable cerebrospinal fluid shunts. The purpose of this study was to evaluate the outcomes and complications of cochlear implantation in children who have a cerebrospinal fluid shunt.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

Twenty pediatric subjects with a cerebrospinal fluid shunt and cochlear implant (CI).

INTERVENTION

Cochlear implantation in the setting of a cerebrospinal fluid shunt.

MAIN OUTCOME MEASURES

Primary outcome measures included descriptive data regarding age at implantation, etiology of hearing loss, medical management, complications, and speech perception outcomes.

RESULTS

The average age of CI candidacy was 30 months with an average 21.5 months delay to implantation. In 45% of cases the laterality of the shunt determined the ear to be implanted. Three of the subjects required a surgical intervention on the shunt before cochlear implantation. Three subjects had a concurrently programmable shunt and activated CI. Two of the three subjects had no complications as a result of the two devices; however, the third subject had significant interactions requiring multiple revision surgeries. For those with the cognitive ability to perform open set, recoded speech perception, the average postoperative Consonant Nucleus Consonant word score in the best aided condition was 65.2% (n = 5).

CONCLUSIONS

Children with a cerebrospinal fluid shunt are viable candidates for cochlear implantation, although they often require additional procedures and considerations before and after implantation.

Intraventricular Hemorrhage in Very Preterm Infants: A Comprehensive Review

Germinal matrix-intraventricular-intraparenchymal hemorrhage (GMH-IVH-IPH) is a major complication of very preterm births before 32 weeks of gestation (WG). Despite progress in clinical management, its incidence remains high before 27 WG. In addition, severe complications may occur such as post-hemorrhagic hydrocephalus and/or periventricular intraparenchymal hemorrhage. IVH is strongly associated with subsequent neurodevelopmental disabilities. For this review, an automated literature search and a clustering approach were applied to allow efficient filtering as well as topic clusters identification. We used a programmatic literature search for research articles related to intraventricular hemorrhage in preterms that were published between January 1990 and February 2020. Two queries ((Intraventricular hemorrhage) AND (preterm)) were used in PubMed. This search resulted in 1093 articles. The data manual curation left 368 documents that formed 12 clusters. The presentation and discussion of the clusters provide a comprehensive overview of existing data on the pathogenesis, complications, neuroprotection and biomarkers of GMH-IVH-IPH in very preterm infants. Clinicians should consider that the GMH-IVH-IPH pathogenesis is mainly due to developmental immaturity of the germinal matrix and cerebral autoregulation impairment. New multiomics investigations of intraventricular hemorrhage could foster the development of predictive biomarkers for the benefit of very preterm newborns.

Ventriculo-peritoneal shunting devices for hydrocephalus

BACKGROUND

Hydrocephalus is a common neurological disorder, caused by a progressive accumulation of cerebrospinal fluid (CSF) within the intracranial space that can lead to increased intracranial pressure, enlargement of the ventricles (ventriculomegaly) and, consequently, to brain damage. Ventriculo-peritoneal shunt systems are the mainstay therapy for this condition, however there are different types of shunt systems.

OBJECTIVES

To compare the effectiveness and adverse effects of conventional and complex shunt devices for CSF diversion in people with hydrocephalus.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (2020 Issue 2); Ovid MEDLINE (1946 to February 2020); Embase (Elsevier) (1974 to February 2020); Latin American and Caribbean Health Science Information Database (LILACS) (1980 to February 2020); ClinicalTrials.gov; and World Health Organization International Clinical Trials Registry Platform.

SELECTION CRITERIA

We selected randomised controlled trials or quasi-randomised trials of different types of ventriculo-peritoneal shunting devices for people with hydrocephalus. Primary outcomes included: treatment failure, adverse events and mortality.

DATA COLLECTION AND ANALYSIS

Two review authors screened studies for selection, assessed risk of bias and extracted data. Due to the scarcity of data, we performed a Synthesis Without Meta-analysis (SWiM) incorporating GRADE for the quality of the evidence.

MAIN RESULTS

We included six studies with 962 participants assessing the effects of standard valves compared to anti-syphon valves, other types of standard valves, self-adjusting CSF flow-regulating valves and external differential programmable pressure valves. All included studies started in a hospital setting and offered ambulatory follow-up. Most studies were conducted in infants or children with hydrocephalus from diverse causes. The certainty of the evidence for most comparisons was low to very low. 1. Standard valve versus anti-syphon valve Three studies with 296 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with standard valve and anti-syphon valves (very low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and anti-syphon valves (range 0 to 2.9%) (low certainty of the evidence). Mortality may be similar in those with standard valves (0%) and anti-syphon valves (0.9%) (RD 0.01%, 95% CI -0.02% to 0.03%, low certainty of the evidence). Ventricular size and head circumference may be similar in those with standard valves and anti-syphon valves (low certainty of the evidence). None of the included studies reported the quality of life of participants. 2. Comparison between different types of standard valves Two studies with 174 randomised participants were included under this comparison. We are uncertain about the incidence of treatment failure in participants with different types of standard valves (early postoperative period: RR 0.41, 95% CI 0.13 to 1.27; at 12 months follow-up: RR 1.17, 95% CI 0.72 to 1.92, very low certainty of the evidence). None of the included studies reported adverse events beyond those included under "treatment failure". We are uncertain about the effects of different types of standard valves on mortality (range 2% to 17%, very low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference. 3. Standard valve versus self-adjusting CSF flow-regulating valve One study with 229 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with standard valves (42.98%) and self-adjusting CSF flow-regulating valves (39.13%) (low certainty of the evidence). The incidence of adverse events may be similar in those with standard valves (range 0 to 1.9%) and those with self-adjusting CSF flow-regulating valves (range 0 to 7.2%) (low certainty of the evidence). The included study reported no deaths in either group in the postoperative period. Beyond the early postoperative period, the authors stated that nine patients died (no disaggregated data by each type of intervention was available, low certainty of the evidence). The included studies did not report the effects of these interventions on quality of life, ventricular size reduction or head circumference. 4. External differential programmable pressure valve versus non-programmable valve One study with 377 randomised participants addressed this comparison. The incidence of treatment failure may be similar in those with programmable valves (52%) and non-programmable valves (52%)  (RR 1.02, 95% CI 0.84 to 1.24, low certainty of the evidence). The incidence of adverse events may be similar in those with programmable valves (6.19%) and non-programmable valves (6.01%) (RR 0.97, 95% CI 0.44 to 2.15, low certainty of the evidence). The included study did not report the effect of these interventions on mortality, quality of life or head circumference. Ventricular size reduction may be similar in those with programmable valves and non-programmable valves (low certainty of the evidence).

AUTHORS' CONCLUSIONS

Standard shunt valves for hydrocephalus compared to anti-syphon or self-adjusting CSF flow-regulating valves may cause little to no difference on the main outcomes of this review, however we are very uncertain due to the low to very low certainty of evidence. Similarly, different types of standard valves and external differential programmable pressure valves versus non-programmable valves may be associated with similar outcomes. Nevertheless, this review did not include valves with the latest technology, for which we need high-quality randomised controlled trials focusing on patient-important outcomes including costs.

Endoscopic third ventriculostomy in children with third ventricular pressure gradient and open ventricular outlets on MRI

OBJECTIVE

Patients with non-communicating hydrocephalus due to aqueductal stenosis are often successfully treated with endoscopic third ventriculocisternostomy (ETV). In hydrocephalus, due to other locations of obstruction of the major CSF pathways, endoscopic treatment may also be a good option. We investigated our cohort of patients treated by ETV with patent ventricular outflow but pressure gradient signs at the third ventricle in a single-center retrospective study.

METHODS

We retrospectively reviewed records and imaging studies of 137 patients who underwent an ETV in our department in the time period of June 2010 to March 2018. We included patients who showed the following findings in MRI: 1st: open Sylvian aqueduct, 2nd: open outlets of the 4th ventricle, 3rd: open spinal canal, 4th: intra-/extraventricular pressure gradient seen at the 3rd ventricle and excluded patients with history of CSF infection or hemorrhage. Perioperative clinical state and possible complications or reoperations were recorded. Shunt dependency and changes in ventricular dilatation were measured as frontal and occipital horn ratio (FOHR) before surgery and during follow-up.

RESULTS

A total of 21 patients met the defined criteria. During the mean follow-up time of 40.7 ± 30 months (range; 5-102 months), two children had to undergo a re-ETV, and six children (all < 1 year of age) received a VP shunt. ETV shunt-free survival was 100% for children > 1 year of age. The ventricular width measured as FOHR was significantly reduced after ETV 0.5 ± 0.08 (range 0.42-0.69; p < 0.05). FOHR was significantly reduced at last follow-up shunt independent patients (0.47 ± 0.05; range 0.41-0.55; p < 0.001) CONCLUSION: We conclude that ETV seems to be a successful treatment option for patients with MRI signs of intra-/extraventricular pressure gradient at the 3rd ventricle and patent aqueduct and fourth ventricular outlets in children older than 1 year of age. This condition is observed only rarely and warrants further research on a multicenter basis in order to get more solid data of its pathophysiology.

Neonatal Hydrocephalus Treatment with Ultrasmall Valve Implantation

OBJECTIVE

Neonatal hydrocephalus remains a difficult condition to manage, due to high failure rates among all management strategies. Neurosurgeons commonly manage hydrocephalus with ventriculoperitoneal shunt (VPS) implantation, and valves of variable sizes and profiles are available for implantation. This study examines primary ventricular shunt valve implantation complication rates based on valve profiles in pediatric patients with hydrocephalus.

METHODS

This study retrospectively reviews pediatric patients younger than 1 year of age who underwent ventricular shunt placement at a single institution from January 2001 to January 2017. Patients were classified by valve profile and categorized as either ultrasmall valves or regular-sized valves. Time until complication and type of complication were studied.

RESULTS

A total of 156 patients met the inclusion criteria. Forty-eight (31%) patients received an ultrasmall shunt valve, while 108 patients received a regular valve. On average, patients undergoing ultrasmall valve placement were younger (2.1 months) than patients undergoing placement of regular valves (3.1 months) (P = 0.03). The overall complication rate within 2 years of VPS placement was 37.5% in patients with the ultrasmall valve and 41.7% in the regular valve population. There was no difference in 1-year shunt survival rate between the 2 cohorts.

CONCLUSION

Our review did not find a significant difference in complication rates between ultrasmall and regular valves in patients under 1 year of age. However, the etiology of shunt malfunction did differ between the groups. This work further supports evidence suggesting a surgeon's preference for shunt hardware alone does not significantly impact outcome.

GAVCA Study: Randomized, Multicenter Trial to Evaluate the Quality of Ventricular Catheter Placement with a Mobile Health Assisted Guidance Technique

BACKGROUND

Freehand ventricular catheter placement may represent limited accuracy for the surgeon's intent to achieve primary optimal catheter position.

OBJECTIVE

To investigate the accuracy of a ventricular catheter guide assisted by a simple mobile health application (mhealth app) in a multicenter, randomized, controlled, simple blinded study (GAVCA study).

METHODS

In total, 139 eligible patients were enrolled in 9 centers. Catheter placement was evaluated by 3 different components: number of ventricular cannulation attempts, a grading scale, and the anatomical position of the catheter tip. The primary endpoint was the rate of primary cannulation of grade I catheter position in the ipsilateral ventricle. The secondary endpoints were rate of intraventricular position of the catheter's perforations, early ventricular catheter failure, and complications.

RESULTS

The primary endpoint was reached in 70% of the guided group vs 56.5% (freehand group; odds ratio 1.79, 95% confidence interval 0.89-3.61). The primary successful puncture rate was 100% vs 91.3% (P = .012). Catheter perforations were located completely inside the ventricle in 81.4% (guided group) and 65.2% (freehand group; odds ratio 2.34, 95% confidence interval 1.07-5.1). No differences occurred in early ventricular catheter failure, complication rate, duration of surgery, or hospital stay.

CONCLUSION

The guided ventricular catheter application proved to be a safe and simple method. The primary endpoint revealed a nonsignificant improvement of optimal catheter placement among the groups. Long-term follow-up is necessary in order to evaluate differences in catheter survival among shunted patients.

Global hydrocephalus epidemiology and incidence: systematic review and meta-analysis

OBJECTIVE

Hydrocephalus is one of the most common brain disorders, yet a reliable assessment of the global burden of disease is lacking. The authors sought a reliable estimate of the prevalence and annual incidence of hydrocephalus worldwide.

METHODS

The authors performed a systematic literature review and meta-analysis to estimate the incidence of congenital hydrocephalus by WHO region and World Bank income level using the MEDLINE/PubMed and Cochrane Database of Systematic Reviews databases. A global estimate of pediatric hydrocephalus was obtained by adding acquired forms of childhood hydrocephalus to the baseline congenital figures using neural tube defect (NTD) registry data and known proportions of posthemorrhagic and postinfectious cases. Adult forms of hydrocephalus were also examined qualitatively.

RESULTS

Seventy-eight articles were included from the systematic review, representative of all WHO regions and each income level. The pooled incidence of congenital hydrocephalus was highest in Africa and Latin America (145 and 316 per 100,000 births, respectively) and lowest in the United States/Canada (68 per 100,000 births) (p for interaction < 0.1). The incidence was higher in low- and middle-income countries (123 per 100,000 births; 95% CI 98-152 births) than in high-income countries (79 per 100,000 births; 95% CI 68-90 births) (p for interaction < 0.01). While likely representing an underestimate, this model predicts that each year, nearly 400,000 new cases of pediatric hydrocephalus will develop worldwide. The greatest burden of disease falls on the African, Latin American, and Southeast Asian regions, accounting for three-quarters of the total volume of new cases. The high crude birth rate, greater proportion of patients with postinfectious etiology, and higher incidence of NTDs all contribute to a case volume in low- and middle-income countries that outweighs that in high-income countries by more than 20-fold. Global estimates of adult and other forms of acquired hydrocephalus are lacking.

CONCLUSIONS

For the first time in a global model, the annual incidence of pediatric hydrocephalus is estimated. Low- and middle-income countries incur the greatest burden of disease, particularly those within the African and Latin American regions. Reliable incidence and burden figures for adult forms of hydrocephalus are absent in the literature and warrant specific investigation. A global effort to address hydrocephalus in regions with the greatest demand is imperative to reduce disease incidence, morbidity, mortality, and disparities of access to treatment.

Infantile Hydrocephalus: Health-Related Quality of Life Outcome following Ventriculoperitoneal Shunt

Aims:

To investigate the impact of Ventriculo-Peritoneal Shunt (VPS) on the Health-Related Quality of Life (HRQOL) of children with the infantile hydrocephalus who underwent their first shunt insertion in the first year of life. To compare the outcome of health domains according to sex, follow-up period, etiology and shunt valve type (fixed versus programmable pressure).

Methods:

102 children ≤1 years old at the time of new-onset hydrocephalus and shunt insertion. Age-appropriate PedsQL 4.0 versions were completed by the parents or caregivers with the assistance of single neurosurgery resident. Patients were divided into subgroups according to etiology; neural tube defect associated hydrocephalus (NTD-H), intra-ventricular hemorrhage associated with infantile hydrocephalus (IVH-H) and according to the shunt valve type; fixed versus programmable. Statistical analyses were performed using SPSS, IBM version 20. PedsQL 4.0 was presented using mean and standard deviations.

Results:

A decreasing social domain score at 1-3 years follow up (n=61) compared to 1 year follow up (n=41) was observed. The two groups did not differ significantly in sex distribution. The mean cognitive score was significantly lower in patients with IVH-H of prematurity compared to NTD-H. Better physical and cognitive domains in programmable shunts were compared to fixed pressure type.

Conclusion:

IVH-H associated with worse cognitive function possibly due to associated brain damage was reported. With long-term follow-up, social function decline probably due to the patients’ awareness of their disability was observed. Programmable shunt valve is recommended over fixed type due to the improvement in physical and cognitive functions. Sex of the patients did not affect the outcome.

Outcome Analysis of Patients of Congenital Hydrocephalus with Ventriculoperitoneal Shunt at a Tertiary Care Hospital in North India

INTRODUCTION

Ventriculoperitoneal (VP) shunt is a commonly performed neurosurgical procedure in pediatric surgical practice. This study is aimed at determining the outcome of congenital hydrocephalus patients who underwent shunt surgery at our center.

MATERIALS AND METHODS

A total of 278 operated cases of congenital hydrocephalus with a minimum follow-up of 6 months were analyzed in terms of complications. Hydrocephalus associated with intracranial hemorrhage, neural tube defects, and ventriculitis were excluded from the study.

RESULTS

Complications were observed in 32.0% (89/278) of cases. Shunt block and chamber migration were the most common complications (29.21%). Abdominal wound complications were seen in 4.49% of cases. Shunt exposure due to erosion of overlying skin was noted in 6 patients. Shunt infection was diagnosed in only 9 patients (4.4%). New-onset seizures were seen in 4 cases. Overall, 21% of patients required redo shunt and there were 2 mortalities.

CONCLUSION

VP shunt continues to have high complication rates. Shunt migration and new-onset seizure disorders are important late complications. In spite of inherent problems, shunt surgery is the procedure of choice until a safer effective alternative is available.

Shunt Devices for Neurointensivists: Complications and Management

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

The applicability of fixed and adjustable gravitational shunt valves in two different clinical settings

BACKGROUND

Gravitational shunt valves and most recently the adjustable proSA® gravitational valve have been designed to counteract overdrainage and thereby improving clinical outcome. So far, the applicability in a broader mix of hydrocephalus patients is unrevealed. The aim of this study was to evaluate the utility of gravitational valves in two different clinical settings.

METHODS

This retrospective double-center cohort study was enabled by two different shunt management policies. At Rigshospitalet, patients with a complicated shunt history receiving a proGAV® and proSA® shunt system during surgical revision were included, and clinical outcome in the follow-up periods before and after was compared. At Aarhus University Hospital, a combination of a proGAV® and a fixed (SA®) or adjustable (proSA®) gravitational valve was used in all shunt procedures. Clinical outcome in a 2-year follow-up period was compared to a cohort receiving non-gravitational valves in the period before the transition to gravitational valves.

RESULTS

Twenty-two patients were included at Rigshospitalet. Mean follow-up time before and after proGAV® and proSA® implantation was 2.3 and 1.5 years, respectively. In each patient, roughly two surgical revisions (p 0.031) and two hospitalizations (p 0.009) were avoided each year after proGAV® and proSA® implantation. At Aarhus University Hospital, 90 patients with non-gravitational valves and 98 patients with gravitational valves were included. Changes in clinical outcome parameters and shunt survivals were either stable or statistically insignificant.

CONCLUSIONS

Gravitational valves are safe and useful in clinical practice and represent an equivalent alternative as a first-line shunt valve in a broad mix of patients, while proSA® valves should be considered for complex shunt patients.

Intracranial Hypotension and Hypertension Associated With Reconstructive Cranioplasty After Decompressive Craniectomy: Report of a Lethal Complication With Recommended Strategies for Future Avoidance

Reconstructive cranioplasty can be associated with many complications and add to the not insignificant potential risks associated with decompressive craniectomy. In the setting of post-traumatic hydrocephalus, treatment with a ventriculoperitoneal (VP) shunt prior to reconstructive cranioplasty likely increases these risks even further. The authors report a case of a 17-year-old male with a history of a severe closed head injury who initially suffered a life-threatening complication associated with intracranial hypotension after cranioplasty only to succumb to malignant intracranial hypertension following a second cranioplasty attempt. To our knowledge, this is the first description of a single patient developing both these disparate complications after reconstructive cranioplasty and emphasizes the likely synergistic hazards involved with decompressive craniectomy in the setting of a VP shunt in particular and the overall myriad potential complications that may be associated with reconstructive cranioplasty in general.

Efficacy and safety of programmable shunt valves for hydrocephalus: A meta-analysis

OBJECTIVES

Shunt implantation is an option in the treatment of hydrocephalus. However, the benefits and adverse effects of programmable shunt valves have not been well assessed.

MATERIALS AND METHODS

Randomized controlled trials (RCTs) and observational studies assessing the efficacy and safety of programmable valves (PV) treatment for hydrocephalus were identified from electronic databases (PubMed, EMBASE, and Cochrane library). The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.

RESULTS

Three RCTs and eight observational studies met the inclusion criteria including 2622 subjects. Compared with non-PV, PV treatment did not have a statistically significant effect on one-year shunt survival rate [relative risk (RR), 1.06; 95% confidence interval (CI), 0.84-1.35], Substantial heterogeneity was observed between studies (P = 0.09; I² = 65%). PV administration significantly reduced revision rate (RR, 0.56; 95% CI, 0.45-0.69; I² = 29%; P = 0.23) and over- or under-drainage complications rate (RR, 0.55; 95% CI, 0.32-0.96). PV was not associated with increased rates of other adverse events, including overall complications rate, infection rate and catheter-related complications rate.

CONCLUSIONS

PV treatment is safe and may reduce the revision rate and over- or under-drainage complication rate, especially in patients aged less than 18 years with hydrocephalus. PV treatment is not associated with decreased overall complication rates in patients with hydrocephalus, but the trial sequential analysis indicate more studies are needed to confirm this result.

Management and Outcome of Infantile Hydrocephalus in a Tertiary Health Institution in Nigeria

Background:

Hydrocephalus is a leading cause of disability among children worldwide. The outcome depends on morphology and whether insult is pre- or post-natal. There has been improvement in morbidity in developed countries due to improved surgical care. A paucity of trained personnel impacts negatively on care and outcome of infants with hydrocephalus in many low-income countries resulting poorer outcome. We conducted an audit of patients with hydrocephalus managed in our institution to determine common etiology and outcome.

Object:

The objective of this retrospective review was to conduct an audit of hydrocephalus care in our institution.

Materials and Methods:

Information was retrieved from case notes, ward records, imaging results, operation notes, and follow-up clinic charts. Type of hydrocephalus, onset, treatment offered, outcome, complications, and follow-up duration were documented.

Results:

Management of 58 infants with complete data was analyzed. Most hydrocephalus 40 (69%) were congenital with 14 (35%) occurring in association with myelomeningocele and 8 patients confirmed with aqueductal stenosis. Ventriculoperitoneal shunts insertion 53 (91%) was the most common treatment modality.

Conclusions:

There is need to improve surgical intervention in the form of endoscopic third ventriculostomy in suitable patients. Subsiding cost of care may be considered for indigent patients.

Cerebrospinal Fluid Shunting Complications in Children

Although cerebrospinal fluid (CSF) shunt placement is the most common procedure performed by pediatric neurosurgeons, shunts remain among the most failure-prone life-sustaining medical devices implanted in modern medical practice. This article provides an overview of the mechanisms of CSF shunt failure for the 3 most commonly employed definitive CSF shunts in the practice of pediatric neurosurgery: ventriculoperitoneal, ventriculopleural, and ventriculoatrial. The text has been partitioned into the broad modes of shunt failure: obstruction, infection, mechanical shunt failure, overdrainage, and distal catheter site-specific failures. Clinical management strategies for the various modes of shunt failure are discussed as are research efforts directed towards reducing shunt complication rates. As it is unlikely that CSF shunting will become an obsolete procedure in the foreseeable future, it is incumbent on the pediatric neurosurgery community to maintain focused efforts to improve our understanding of and management strategies for shunt failure and shunt-related morbidity.

Appraisal of the Quality of Neurosurgery Clinical Practice Guidelines

OBJECTIVE

The rate of neurosurgery guidelines publications was compared over time with all other specialties. Neurosurgical guidelines and quality of supporting evidence were then analyzed and compared by subspecialty.

METHODS

The authors first performed a PubMed search for "Neurosurgery" and "Guidelines." This was then compared against searches performed for each specialty of the American Board of Medical Specialties. The second analysis was an inventory of all neurosurgery guidelines published by the Agency for Healthcare Research and Quality Guidelines clearinghouse. All Class I evidence and Level 1 recommendations were compared for different subspecialty topics.

RESULTS

When examined from 1970-2010, the rate of increase in publication of neurosurgery guidelines was about one third of all specialties combined (P < 0.0001). However, when only looking at the past 5 years the publication rate of neurosurgery guidelines has converged upon that for all specialties. The second analysis identified 49 published guidelines for assessment. There were 2733 studies cited as supporting evidence, with only 243 of these papers considered the highest class of evidence (8.9%). These papers were used to generate 697 recommendations, of which 170 (24.4%) were considered "Level 1" recommendations.

CONCLUSION

Although initially lagging, the publication of neurosurgical guidelines has recently increased at a rate comparable with that of other specialties. However, the quality of the evidence cited consists of a relatively low number of high-quality studies from which guidelines are created. Wider implications of this must be considered when defining and measuring quality of clinical performance in neurosurgery.

Predicting shunt failure in children: should the global shunt revision rate be a quality measure?

OBJECT

Ventricular shunts for pediatric hydrocephalus continue to be plagued with high failure rates. Reported risk factors for shunt failure are inconsistent and controversial. The raw or global shunt revision rate has been the foundation of several proposed quality metrics. The authors undertook this study to determine risk factors for shunt revision within their own patient population.

METHODS

In this single-center retrospective cohort study, a database was created of all ventricular shunt operations performed at the authors' institution from January 1, 2010, through December 2013. For each index shunt surgery, demographic, clinical, and procedural variables were assembled. An "index surgery" was defined as implantation of a new shunt or the revision or augmentation of an existing shunt system. Bivariate analyses were first performed to evaluate individual effects of each independent variable on shunt failure at 90 days and at 180 days. A final multivariate model was chosen for each outcome by using a backward model selection approach.

RESULTS

There were 466 patients in the study accounting for 739 unique ("index") operations, for an average of 1.59 procedures per patient. The median age for the cohort at the time of the first shunt surgery was 5 years (range 0-35.7 years), with 53.9% males. The 90- and 180-day shunt failure rates were 24.1% and 29.9%, respectively. The authors found no variable-demographic, clinical, or procedural-that predicted shunt failure within 90 or 180 days.

CONCLUSIONS

In this study, none of the risk factors that were examined were statistically significant in determining shunt failure within 90 or 180 days. Given the negative findings and the fact that all other risk factors for shunt failure that have been proposed in the literature thus far are beyond the control of the surgeon (i.e., nonmodifiable), the use of an institution's or individual's global shunt revision rate remains questionable and needs further evaluation before being accepted as a quality metric.