Management of neonatal hydrocephalus: feasibility of use and safety of two programmable (Sophy and Polaris) valves

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.

Preterm-related posthemorrhagic hydrocephalus: Review of our institutional series with a long-term follow-up

INTRODUCTION

Preterm-related posthemorrhagic hydrocephalus is a major cause of neurological impairment and a common indication for a ventriculoperitoneal shunt in infants that are prone to diverse complications. Protocols of diagnosis and treatment are in continuous evolution and require evaluation of their results.

OBJECTIVE

To review the clinical characteristics and results of a series of preterm-related posthemorrhagic hydrocephalus needing a definitive shunt from 1982 to 2020 in our institution. As a secondary objective we evaluated the safety of the changes in our protocol of treatment from 2015.

METHODS

Retrospective review, clinical investigation.

RESULTS

133 patients were implanted a shunt in the study period. Shunt infection was diagnosed in 15 patients. Proximal shunt obstruction as the first complication was diagnosed in 30% of cases at one year, 37% at two years and 46% at five years. 61 patients developed very small or collapsed ventricles at last follow-up. Two thirds of our patients achieved normal neurological development or mild impairment. Changes in protocol did not significantly modify clinical results although improvement in most outcomes was observed. Mean follow-up was over nine years.

CONCLUSIONS

Clinical outcomes are comparable to previous reported data. Changes in protocol proved to be safe and improved our results. Programmable shunts can be used safely in preterm patients although they may not prevent tendency towards ventricular collapse, which is very common after long follow-up.

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.

Infant hydrocephalus: what valve first?

PURPOSE

To review the use of different valve types in infants with hydrocephalus, in doing so, determining whether an optimal valve choice exists for this patient cohort.

METHODS

We conducted (1) a literature review for all studies describing valve types used (programmable vs. non-programmable, valve size, pressure) in infants (≤ 2 years) with hydrocephalus, (2) a review of data from the pivotal BASICS trial for infant patients and (3) a separate, institutional cohort study from Alder Hey Children's Hospital NHS Foundation Trust. The primary outcome was any revision not due to infection.

RESULTS

The search identified 19 studies that were included in the review. Most did not identify a superior valve choice between programmable and non-programmable, small compared to ultra-small, and differential pressure compared to flow-regulating valves. Five studies investigated a single-valve type without a comparator group. The BASICS data identified 391 infants, with no statistically significant difference between gravitational and programmable subgroups. The institutional data from our tertiary referral centre did not reveal any significant difference in failure rate between valve subtypes.

CONCLUSION

Our review highlights the challenges of valve selection in infant hydrocephalus, reiterating that the concept of an optimal valve choice in this group remains a controversial one. While the infant-hydrocephalic population is at high risk of valve failure, heterogeneity and a lack of direct comparison between valves in the literature limit our ability to draw meaningful conclusions. Data that does exist suggests at present that there is no difference in non-infective failure rate are increasing in number, with the British valve subtypes in infant hydrocephalus, supported by both the randomised trial and institutional data in this study.

Surgical outcome of the shunt: 15-year experience in a single institution

PURPOSE

Surgical outcome after shunt insertion in pediatric hydrocephalus can vary greatly. Although first shunt survival rates and complications have been studied by several teams, much less is known about survival and complications of subsequent systems. The goals of this study were to evaluate the surgical outcome in a series of pediatric patients followed for a long time and establish the differences between first and subsequent extracranial shunt survival and complications.

METHODS

We undertook a retrospective study in pediatric patients treated with ventriculoperitoneal shunts between 2000 and 2015 at our institution. Surgical outcome was assessed, and different shunt survival curves were studied with Kaplan-Meier. Complications related to each shunt failure were examined and compared.

RESULTS

A total of 166 patients underwent 425 procedures, with a mean follow-up period of 93 months. The median number of shunt revision surgeries was 2. Shunt survival rates were better with the first shunt compared to those with the subsequent shunts. The main complication necessitating system revision surgery was overdrainage, the frequency of proximal and distal dysfunctions was similar in all the shunt failures, and isolated ventricle and infection were more frequent in younger patients. Shunt-related infections accounted for 7 % of the procedures, and the shunt independence rate was 10 %.

CONCLUSIONS

The frequency of complications related to shunt failure in pediatric patients changes during follow-up. A strict protocol of overdrainage detection and active treatment could explain the need for repeat surgeries and the progressively shorter shunt survival time in our series.

Long-term survival rates of gravity-assisted, adjustable differential pressure valves in infants with hydrocephalus

OBJECTIVE The use of adjustable differential pressure valves with gravity-assisted units in shunt therapy of children with hydrocephalus was reported to be feasible and promising as a way to avoid chronic overdrainage. In this single-center study, the authors' experiences in infants, who have higher rates of shunt complications, are presented. METHODS All data were collected from a cohort of infants (93 patients [37 girls and 56 boys], less than 1 year of age [mean age 4.1 ± 3.1 months]) who received their first adjustable pressure hydrocephalus shunt as either a primary or secondary implant between May 2007 and April 2012. Rates of valve and shunt failure were recorded for a total of 85 months until the end of the observation period in May 2014. RESULTS During a follow-up of 54.2 ± 15.9 months (range 26-85 months), the Kaplan-Meier rate of shunt survival was 69.2% at 1 year and 34.1% at 85 months; the Kaplan-Meier rate of valve survival was 77.8% at 1 year and 56% at 85 months. Survival rates of the shunt were significantly inferior if the patients had previous shunt surgery. During follow-up, 44 valves were exchanged in cases of infection (n = 19), occlusion (n = 14), dysfunction of the adjustment unit (n = 10), or to change the gravitational unit (n = 1). CONCLUSIONS Although a higher shunt complication rate is observed in infant populations compared with older children, reasonable survival rates demonstrate the feasibility of using this sophisticated valve technology. The gravitational unit of this valve is well tolerated and its adjustability offers the flexible application of opening pressure in an unpredictable cohort of patients. This may adequately address overdrainage-related complications from early in treatment.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 2: Management of posthemorrhagic hydrocephalus in premature infants

OBJECT

The objective of this systematic review and analysis was to answer the following question: What are the optimal treatment strategies for posthemorrhagic hydrocephalus (PHH) in premature infants?

METHODS

Both the US National Library of Medicine and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to PHH. Two hundred thirteen abstracts were reviewed, after which 98 full-text publications that met inclusion criteria that had been determined a priori were selected and reviewed.

RESULTS

Following a review process and an evidentiary analysis, 68 full-text articles were accepted for the evidentiary table and 30 publications were rejected. The evidentiary table was assembled linking recommendations to strength of evidence (Classes I-III).

CONCLUSIONS

There are 7 recommendations for the management of PHH in infants. Three recommendations reached Level I strength, which represents the highest degree of clinical certainty. There were two Level II and two Level III recommendations for the management of PHH. Recommendation Concerning Surgical Temporizing Measures: I. Ventricular access devices (VADs), external ventricular drains (EVDs), ventriculosubgaleal (VSG) shunts, or lumbar punctures (LPs) are treatment options in the management of PHH. Clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty. Recommendation Concerning Surgical Temporizing Measures: II. The evidence demonstrates that VSG shunts reduce the need for daily CSF aspiration compared with VADs.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty. Recommendation Concerning Routine Use of Serial Lumbar Puncture: The routine use of serial lumbar puncture is not recommended to reduce the need for shunt placement or to avoid the progression of hydrocephalus in premature infants.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Nonsurgical Temporizing Agents: I. Intraventricular thrombolytic agents including tissue plasminogen activator (tPA), urokinase, or streptokinase are not recommended as methods to reduce the need for shunt placement in premature infants with PHH.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Nonsurgical Temporizing Agents. II. Acetazolamide and furosemide are not recommended as methods to reduce the need for shunt placement in premature infants with PHH.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Timing of Shunt Placement: There is insufficient evidence to recommend a specific weight or CSF parameter to direct the timing of shunt placement in premature infants with PHH. Clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty. Recommendation Concerning Endoscopic Third Ventriculostomy: There is insufficient evidence to recommend the use of endoscopic third ventriculostomy (ETV) in premature infants with posthemorrhagic hydrocephalus.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty.

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

OBJECT

The objective of this systematic review was to examine the existing literature to compare differing shunt components used to treat hydrocephalus in children, find whether there is a superior shunt design for the treatment of pediatric hydrocephalus, and make evidence-based recommendations for the selection of shunt implants when placing shunts.

METHODS

Both the US National Library of Medicine PubMed/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words chosen to identify publications comparing the use of shunt implant components. Abstracts of these publications were reviewed, after which studies meeting the inclusion criteria were selected. An evidentiary table was compiled summarizing the selected articles and quality of evidence. These data were then analyzed by the Pediatric Hydrocephalus Systematic Review and Evidence-Based Guidelines Task Force to consider evidence-based treatment recommendations.

RESULTS

Two hundred sixty-nine articles were identified using the search parameters, and 43 articles were recalled for full-text review. Of these, 22 papers met the study criteria for a comparison of shunt components and were included in the evidentiary table. The included studies consisted of 1 Class I study, 11 Class II studies, and 10 Class III studies. The remaining 21 articles were excluded.

CONCLUSIONS

An analysis of the evidence did not demonstrate a clear advantage for any specific shunt component, mechanism, or valve design over another.

RECOMMENDATION

There is insufficient evidence to demonstrate an advantage for one shunt hardware design over another in the treatment of pediatric hydrocephalus. Current designs described in the evidentiary tables are all treatment options.

STRENGTH OF RECOMMENDATION

Level I, high degree of clinical certainty.

RECOMMENDATION

There is insufficient evidence to recommend the use of a programmable valve versus a nonprogrammable valve. Programmable and nonprogrammable valves are both options for the treatment of pediatric hydrocephalus.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty.

Nonprogrammable and programmable cerebrospinal fluid shunt valves: a 5-year study

OBJECT

Programmable valves (PVs) for shunting CSF have increasingly replaced nonprogrammable valves (NPVs). There have been only a few longer-term studies (≥ 5 years) conducted that have compared the effectiveness of NPVs with that of PVs for children with hydrocephalus, and only 1 study has reported NPVs as being favorable over PVs. The objective of this retrospective study was to compare the long-term survival of these 2 types of shunt valves.

METHODS

The authors collected data for all patients who underwent CSF shunt insertion or revision between January 1, 2000, and December 31, 2008. Patients underwent follow-up for a minimum of 2 years postoperatively. Statistical analyses were done using chi-square, Kaplan-Meier survival curve, and multivariate analyses.

RESULTS

A total of 616 valves were implanted, of which 313 were PVs and 303 were NPVs. Of these, 253 were original shunt implantations and 363 were revisions. The proportion of 5-year survival for NPVs (45.8%) was significantly higher than that for PVs (19.8%) (p = 0.0005, log-rank). The NPVs that survived longer than 6 months also survived through the 5th year better than the PVs (p = 0.0001).

CONCLUSIONS

The authors' data suggest that NPVs survive longer than PVs in children, but there is a need for prospective, case-control studies to confirm these data.

Initial proximal obstruction of ventriculoperitoneal shunt in patients with preterm-related posthaemorrhagic hydrocephalus

BACKGROUND/AIMS

Obstruction is the most common complication of ventriculoperitoneal shunts in patients with hydrocephalus. Despite technical advances, rates of obstruction have barely decreased and remain at over 40% of cases. Patients suffering from preterm-related posthaemorrhagic hydrocephalus are considered a group with a particularly high risk of obstruction. The aim of the present study was to review our series of patients with preterm-related posthaemorrhagic hydrocephalus and analyse the occurrence of the first ventricular shunt obstruction as well as the related clinical and radiological factors.

METHODS

We conducted a retrospective review of 103 cases treated from 1982 to 2010. Descriptive analysis, raw and adjusted bivariate correlations and survival analysis were performed.

RESULTS

Over the course of the follow-up, 42 patients presented at least one episode of obstruction that required proximal revision. Medium-opening pressure valves were associated with a higher rate of obstruction compared to low-opening pressure valves; however, in our series this association became statistically significant only in patients with a weight of over 2,000 g at the time of surgery (odds ratio 6.75). The occurrence of previous infection and the development of late slit ventricle syndrome were also significantly associated with obstruction of the ventricular catheter (odds ratios 3.35 and 4.27, respectively).

CONCLUSIONS

Rates of shunt obstruction in preterm-related posthaemorrhagic hydrocephalus remain high but do not seem to be higher than in other groups of paediatric hydrocephalus. Prevention of infection and the use of the appropriate type of valve design can help to decrease the incidence of proximal shunt obstruction, which in turn could decrease the incidence of symptomatic slit ventricle syndromes.

The Adjustable proGAV Shunt

OBJECTIVE

To evaluate the reliability of the gravitation-assisted adjustable proGAV shunt system with a prospective multicenter study conducted in 10 German hospitals.

METHODS

Enrollment for this observational study began in April 2005 and concluded in February 2006. The protocol required re-examinations 3 and 6 months postoperatively and fixed the endpoint of follow-up at 12 months after implantation. Patients with different types of adult, juvenile, and pediatric hydrocephalus were included and 165 patients were enrolled; 9 died and 12 had incomplete follow-up.

RESULTS

Of the assessable 144 patients, 130 completed the protocol after 12 months, whereas 14 failed because of the need to explant the device, mainly because of infection. In 12 patients, components of the shunt, not the valve, were revised. In 65 of the 144 patients, there were 102 readjustments of the valve in 67 incidences because of underdrainage and in 35 because of overdrainage. In 1 case, readjustment was not possible. Determination of pressure level with the verification instrument was safe and corresponded to the required x-ray controls after adjustments. No unintended readjustments were noted.

CONCLUSION

The proGAV is a safe and reliable device.

Keeping CSF valve function with urokinase in children with intra-ventricular haemorrhage and CSF shunts

BACKGROUND

Intra-ventricular haemorrhage (IVH) can occur spontaneously or during the surgical revision of ventricular cerebrospinal fluid (CSF) shunts.

AIM

The aim of the study was to report the safety and efficacy of an original method for treatment of IVH that may occur at the time of valve revision aimed at maintaining the function of previously implanted CSF shunts.

PATIENTS AND METHODS

We reviewed the medical records of six patients who experienced an IVH in the presence of a previously placed ventriculoperitoneal (VP) shunt. Five of the haemorrhages occurred during ventricular catheter replacement and the remaining one in a child given a VP shunt who sustained a spontaneous intra-cerebral haemorrhage. We inserted an external ventricular drainage without removing the original shunt. Urokinase was administered via the ventricular drain during several days until blood clearance in the CSF. Disappearance of the ventricular clots was checked by a cranial computerised tomography scan, while CSF shunt function was verified by the children's evolution and/or by a reservoir tap.

RESULTS

Follow-up evaluation of the six patients demonstrated that the existing VP shunts were functioning appropriately and that the treatment was safe.

CONCLUSIONS

Patients with IVH complicating ventricular catheter replacement and patients with spontaneous bleeding who harbour a VP shunt can be treated by intra-ventricular urokinase to avoid the removal of the initial shunt. The technique has proven to be safe and utilises the ventricular drain placed for the acute management of the IVH. Shunt replacement will always be possible in case of failure of the technique we are reporting.