Treatment of hydrocephalus determined by the European Orbis Sigma Valve II survey: a multicenter prospective 5-year shunt survival study in children and adults in whom a flow-regulating shunt was used

Prospective evaluation of flow-regulated valves for idiopathic normal pressure hydrocephalus: 1-year results

OBJECTIVE

Overdrainage and frequent reprogramming are common problems with programmable valves after ventriculoperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). Non-adjustable, flow-regulated valves offer a potential solution to these problems, but there is limited data on their efficacy. This study will evaluate neurological improvement and overdrainage rates within one year of treatment with a flow-regulated valve.

PATIENTS AND METHODS

This prospective study analyzes 45 iNPH patients (median age: 73 years) treated with a flow-regulated valve. Clinical evaluations were performed at baseline, postoperatively, and at 3, 6, and 12 months after surgery. The primary efficacy endpoint was improvement of at least 5 points on the iNPH grading scale at follow-up. The safety endpoint was radiographic evidence of overdrainage.

RESULTS

All patients presented with gait disturbance, 35 (78 %) had cognitive impairment, and 35 (78 %) had urinary incontinence. The median duration of symptoms was 24 months. The total iNPH score improved in 33/41 (81 %) at 3 months, in 29/34 (85 %) at 6 months, and in 22/29 (64 %) at 12 months. Overall, 40/45 (89 %) patients had a significant improvement on the iNPH scale. Secondary worsening of symptoms after initial improvement was observed in 5 (11 %) patients. Overdrainage occurred in one patient (2 %) requiring surgical evacuation.

CONCLUSION

Treatment of iNPH patients with flow-regulated valves resulted in a good neurological outcome with minimal rates of overdrainage. These results are encouraging and justify the clinical use of these valve types.

Chronic Pediatric Headache as a Manifestation of Shunt Over-Drainage and Slit Ventricle Syndrome in Patients Harboring a Cerebrospinal Fluid Diversion System: A Narrative Literature Review

The main subject of the current review is a specific subtype of headache, which is related to shunt over-drainage and slit ventricle syndrome, in pediatric patients harboring an implanted shunt device for the management of hydrocephalus. This clinical entity, along with its impairment regarding the quality of life of the affected individuals, is generally underestimated. This is partly due to the absence of universally agreed-upon diagnostic criteria, as well as due to a misunderstanding of the interactions among the implicated pathophysiological mechanisms. A lot of attempts have been performed to propose an integrative model, aiming at the determination of all the offending mechanisms of the shunt over-drainage syndrome, as well as the determination of all the clinical characteristics and related symptomatology that accompany these secondary headaches. This subcategory of headache, named postural dependent headache, can be associated with nausea, vomiting, and/or radiological signs of slim ventricles and/or subdural collections. The ultimate goal of our review is to draw clinicians' attention, especially that of those that are managing pediatric patients with permanent, long-standing, ventriculoperitoneal, or, less commonly, ventriculoatrial shunts. We attempted to elucidate all clinical and neurological characteristics that are inherently related to this type of headache, as well as to highlight the current management options. This specific subgroup of patients may eventually suffer from severe, intractable headaches, which may negatively impair their quality of daily living. In the absence of any other clinical condition that could be incriminated as the cause of the headache, shunt over-drainage should not be overlooked. On the contrary, it should be seriously taken into consideration, and its management should be added to the therapeutic armamentarium of such cases, which are difficult to be handled.

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.

Cerebrospinal fluid shunt malfunctions: A reflective review

PURPOSE

Pediatric hydrocephalus is a common and challenging condition. To date, the ventriculoperitoneal shunt (VPS) is still the main lifesaving treatment option. Nonetheless, it remains imperfect and is associated with multiple short- and long-term complications. This paper is a reflective review of the current state of the VPS, our knowledge gaps, and the future state of shunts in neurosurgical practice.

METHODS AND RESULTS

The authors' reflections are based on a review of shunts and shunt-related literature.

CONCLUSION

Overall, there is still an urgent need for the neurosurgical community to actively improve current strategies for shunt failures and shunt-related morbidity. The authors emphasize the role of collaborative efforts amongst like-minded clinicians to establish pragmatic approaches to avoid shunt complications.

Antisiphon device: a review of existing mechanisms and clinical applications to prevent overdrainage in shunted hydrocephalic patients

Overdrainage of cerebrospinal fluid is one of the most notorious complications after ventriculoperitoneal shunt implantation. Siphon effect plays a major role in the development of overdrainage. Various overdrainage-preventing devices have been invented to counteract the siphon effect. Though some of the devices are designed to reduce the flow instead of providing antisiphoning effect, they are generally called antisiphon devices (ASDs). The basics of siphoning, the mechanisms and physical properties of currently available devices are described in this article. The clinical efficacy, shunt survival, and considerations on patient factors are also discussed. There are three kinds of ASD design, diaphragm, gravitational, and flow reducing devices. Flow reducing ASD is always open and the flow it controls is relatively stable. On the other hand, it may not provide sufficient flow in nocturnal intracranial pressure elevations. Diaphragm and gravitational devices are sensitive to the position of the patients. Diaphragm device is sensitive to the external pressure and the relative position of the device to the mastoid process. The gravitational device is sensitive to the angle between the axis of the device and the head. Many studies showed encouraging results with gravitational devices. Studies regarding diaphragm devices either showed better or similar outcomes comparing to differential pressure valves. Clinical studies regarding flow-reducing devices and head-to-head comparison between different mechanisms are warranted. This review aims to provide a useful reference for clinical practice of hydrocephalus.

A Review of Passive Constant Flow Regulators for Microfluidic Applications

This review gives an overview of passive constant flow regulators dedicated to microfluidic applications. Without external control and energy consumption, these devices deliver a constant flow rate regardless of pressure variations, making them very attractive for various microfluidic applications, including drug delivery, flow chemistry, point-of-care tests, or microdialysis. This technical review examines progress over the last three decades in the development of these flow regulators and focuses on the working principle, fabrication methods, performance, and potential applications.

A comparison between flow-regulated and adjustable valves used in hydrocephalus during infancy

INTRODUCTION

Ventriculoperitoneal shunt insertion during the neonatal period and early infancy is associated with a high rate of shunt failure when compared to the adult population. Furthermore, the function of flow-regulated valves and differential pressure valves may be different in neonatal hydrocephalus.

METHODS

A retrospective case series of all primary shunt procedures carried out during or immediately following the neonatal period, from August 2011 to February 2018 at Sheffield Children's Hospital. The total sample size was 55. This included 34 patients with adjustable valves (Miethke ProGav) and 21 with flow-regulated valves (Orbis-Sigma); however, only 53 had adequate follow-up.

RESULTS

The overall 1 year shunt survival was 34% (18/53), and there was no significant difference depending on which shunt valve was implanted. The primary shunt infection rate was 11% (6/53) with S. aureus being the most common causative organism. During the first year of life, clinical signs of shunt overdrainage were seen more frequently in patients with adjustable valves than in those with flow-regulated valves (59% [19/32] versus 24% [5/21], p = 0.02). Furthermore, 2 patients in the adjustable valve group developed sagittal craniosynostosis secondary to shunt overdrainage.

CONCLUSION

Shunt failure is high when inserted during or immediately following the neonatal period. Overdrainage may be less common in patients with flow-regulated valves. However, if overdrainage is observed, adjusting the setting of a differential pressure valve can effectively treat the overdrainage without the need for invasive shunt revision surgery.

Suprahepatic space as an alternative site for distal catheter insertion in pseudocyst-associated ventriculoperitoneal shunt malfunction

OBJECTIVE

Distal catheter malfunction due to pseudocyst formation or intraabdominal adhesion is a significant problem, especially in pediatric patients who have limited sites for distal catheter insertion. In this study, the authors present a series of 12 patients with intractable distal shunt malfunctions due to peritoneal pseudocyst formation who underwent distal catheter replacement in the suprahepatic space to reduce the risk of distal catheter malfunction.

METHODS

Twelve consecutive patients with shunt malfunction due to pseudocyst formation who had undergone ventriculosuprahepatic shunting from 2014 to 2019 were identified. According to medical records, after primary evaluations, shunt removal, and antibiotic therapy, they underwent revision surgeries with placement of a distal catheter into the suprahepatic space.

RESULTS

Nine boys and 3 girls, ranging in age from 5 months to 14 years, with one or more episodes of pseudocyst formation, underwent shunt revision with placement of a distal catheter into the suprahepatic space. After a median follow-up of 31 months, none of the patients experienced further distal malfunction.

CONCLUSIONS

The suprahepatic space appears to be a safe place to secure the distal end of a ventricular catheter following pseudocyst formation, with less risk of re-adhesion. This lower risk might be attributable to the lack of omentum in the suprahepatic space.

Management of paediatric hydrocephalous with Miethke fixed pressure gravitational valves. The Alder Hey Children's Hospital experience

OBJECTIVE

The management of paediatric hydrocephalous remains challenging with the complication and revision rates being consistent in the literature. We hypothesise that the use of a fixed pressure gravitational valve for all de novo shunt insertions decreases the rate of functional revisions and that by implementing the routine use of gravitational valves in children, we would see a reduction in over-drainage and slit ventricle syndrome.

METHODS

Retrospective data collection in a single centre, between February 2010 and August 2018. All patients undergoing fixed pressure gravitational Miethke valve insertion were included. We collected data on patients' demographics, reason for shunt insertion, type of valve and time to and reason for first revision. Data analysis was done with SPSS.

RESULTS

A total of 235 patients were included in our study (124 males, 111 females), aged from 0 to 18.6 years (median 0.28). A total of 99 shunt revisions were documented, 30 of which secondary to ventricular catheter malfunction and 28 secondary to infection. The overall mechanical valve survival rates were 88.5%, 86.4% and 85.5% at 1, 2 and 5 years, respectively. Shunt revision due to over-drainage was documented in only 3 cases (1.3%).

CONCLUSION

Our results are in agreement with existing literature regarding shunt failures secondary to all extrinsic factors to the valve (infection and mechanical failure). We have shown that the use of a Miethke fixed pressure valve for all de novo shunt insertions in paediatric hydrocephalus decreases the need for functional revisions with valve survival rates being superior to the ones described for other types.

Recurrent Shoulder Tip Pain After Ventriculoperitoneal Shunt Placement Associated with Infectious Peritonitis with Propionibacterium acnes; A Case Report and Review of the Literature

Ventriculoperitoneal (VP) shunt placement is commonly performed for the treatment of hydrocephalus, and several complications of this procedure are well known. Radiating shoulder tip pain after VP shunt placement has been reported as an unusual complication in a few cases, associated with dislocation of the peritoneal catheter. We described the case of a 9-year-old girl who presented with recurrent radiating shoulder tip pain after VP shunt placement. The pain recurred after peritoneal catheter repositioning because of peritoneal inflammation and adhesion due to peritonitis with Propionibacterium acnes (P. acnes). This bacterium was isolated using 16S ribosomal RNA gene polymerase chain reaction (16S rRNA gene PCR), and anaerobic and prolonged culture tests. After antibacterial treatment, ventriculoarterial (VA) shunt placement was successfully performed. Hemidiaphragm irritation by the peritoneal catheter leads to radiating shoulder tip pain, and peritoneal inflammation and adhesion caused by infectious peritonitis may cause recurrence of this despite catheter repositioning. Clinicians should be aware of shoulder pain as a complication of VP shunt placement, and should consider VA shunt placement as an alternative treatment if this symptom recurs after catheter repositioning. Furthermore, 16S rRNA gene PCR and anaerobic and prolonged culture tests should be considered to detect P. acnes infection.

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.

Pediatric Ventriculoperitoneal Shunt Infection: The Role of Shunt Tract Debridement in Mycobacterium abscessus Eradication

Ventricular shunt infections caused by nontuberculous mycobacteria are uncommon, and those caused by Mycobacterium abscessus are particularly rare. This mycobacterium is intrinsically resistant to first-line anti-tuberculous drugs and is considered the most pathogenic of the atypical, rapidly growing mycobacteria. Given the paucity of reported M. abscessus ventricular shunt infections, the appropriate surgical treatment for these cases, especially in the pediatric setting, has yet to be described. The authors present a 4-year-old male with history of intraventricular hemorrhage resulting in hydrocephalus who presented with an M. abscessus ventricular shunt infection that disseminated to the skin and soft tissue of the entire shunt tract. Despite aggressive antimicrobial therapy, several shunt exchanges, and numerous incisions and debridements of separate infected tract areas, the patient's clinical course was prolonged by multiple relapses and re-admissions. Only after opening and debriding the entire length of the infected tract, which measured 100 cm and extended from the scalp to the groin, and months of intrathecal antibiotics did CSF and tissue culture results become negative, and the entire tract was able to be closed. This article describes the management of the second-encountered pediatric M. abscessus shunt infection along with the management of the 4 previously reported cases. In addition, it highlights the vital role of early, aggressive surgical debridement to achieve infection eradication.

A 12-year single-center retrospective analysis of antisiphon devices to prevent proximal ventricular shunt obstruction for hydrocephalus

OBJECTIVE

Recent evidence points to gravity-dependent chronic shunt overdrainage as a significant, if not leading, cause of proximal shunt failure. Yet, shunt overdrainage or siphoning persists despite innovations in valve technology. The authors examined the effectiveness of adding resistance to flow in shunt systems via antisiphon devices (ASDs) in preventing proximal shunt obstruction.

METHODS

A retrospective observational cohort study was completed on patients who had an ASD (or additional valve) added to their shunt system between 2004 and 2016. Detailed clinical, radiographic, and surgical findings were examined. Shunt failure rates were compared before and after ASD addition.

RESULTS

Seventy-eight patients with shunted hydrocephalus were treated with placement of an ASD several centimeters distal to the primary valve. The records of 12 of these patients were analyzed separately due to a complex shunt revision history (i.e., > 10 lifetime shunt revisions). The authors found that adding an ASD decreased the 1-year ventricular catheter obstruction rates in the "simple" and "complex" groups by 67.3% and 75.8%, respectively, and the 5-year rates by 43.3% and 65.6%, respectively. The main long-term ASD complication was ASD removal for presumed valve pressure intolerance in 5 patients.

CONCLUSIONS

Using an ASD may result in significant reductions in ventricular catheter shunt obstruction rates. If confirmed with prospective studies, this observation would lend further evidence that chronic shunt overdrainage is a central cause of shunt malfunction, and provide pilot data to establish clinical and laboratory studies that assess optimal ASD type, number, and position, and eventually develop shunt valve systems that are altogether resistant to siphoning.

Prospective multicenter studies in pediatric hydrocephalus

Prospective multicenter clinical research studies in pediatric hydrocephalus are relatively rare. They cover a broad spectrum of hydrocephalus topics, including management of intraventricular hemorrhage in premature infants, shunt techniques and equipment, shunt outcomes, endoscopic treatment of hydrocephalus, and prevention and treatment of infection. The research methodologies include randomized trials, cohort studies, and registry-based studies. This review describes prospective multicenter studies in pediatric hydrocephalus since 1990. Many studies have included all forms of hydrocephalus and used device or procedure failure as the primary outcome. Although such studies have yielded useful findings, they might miss important treatment effects in specific subgroups. As multicenter study networks grow, larger patient numbers will allow studies with more focused entry criteria based on known and evolving prognostic factors. In addition, increased use of patient-centered outcomes such as neurodevelopmental assessment and quality of life should be measured and emphasized in study results. Well-planned multicenter clinical studies can significantly affect the care of children with hydrocephalus and will continue to have an important role in improving care for these children and their families.

Ventriculo-peritoneal shunting is a safe and effective treatment for idiopathic intracranial hypertension

PURPOSE

To determine the outcome of ventriculo-peritoneal shunts as a treatment for idiopathic intracranial hypertension (IIH) Materials and Methods: Retrospective case series of 28 patients with IIH and evidence of raised intracranial pressure (ICP) who underwent shunt insertion. Patients were identified from a prospectively updated operative database. A case-notes review was performed and data on type of shunt, pre- and post-operative symptoms, ophthalmological findings and post-operative complications were recorded.

RESULTS

All patients had symptoms of IIH that had failed medical management. Twelve patients had previous lumbo-peritoneal shunts and 2 patients had previous venous sinus stents. All patients had evidence of raised ICP as papilloedema and raised CSF pressure on lumbar puncture. Twenty-seven patients received a ventriculo-peritoneal shunt and 1 patient a ventriculo-atrial shunt. Twenty-six patients received Orbis Sigma Valves and 2 patients Strata valves. At follow-up all patients (100%) had improvement/resolution of papilloedema, 93% had improved visual acuity and 84% had improved headaches. Mean time to last follow-up was 15 (range 4-96) months. Complications occurred in 3 patients (11%): 2 patients required revision of their peritoneal catheters and 1 patient had an anti-siphon device inserted.

CONCLUSIONS

Previous literature reported a ventricular shunt revision rate of 22-42% in the management of IIH. We demonstrate ventriculo-peritoneal shunts to be an effective treatment with a revision rate of 11% compared to the previously reported 22-42%.

Exclusive use of fixed pressure valves for cerebrospinal fluid diversion in a modern adult cohort

Background

There is extensive debate on the role of fixed pressure shunts in the adult population. Most studies assessing fixed pressure valves do not consider the potential for changes in technique and management of shunts. We sought to examine the natural history of fixed pressure.

Methods

We conducted a retrospective chart review of 169 patients undergoing shunt placement by the senior author Daniel Wecht (DW). The etiology of shunt placement, shunt failure rates, and outcome data was assessed for each patient.

Results

Overall, 126 patients underwent initial shunt placement. Thirty-three (26.2%) patients required at least one shunt revision during follow-up. The most common cause of first time revision was mechanical shunt malfunction (13, 39.4%), followed by infection (7, 21.2%), and shunt migration (6, 18.2%). Three patients (9.1%) required revision due to misplaced catheters. Underdrainage or overdrainage of shunts each resulted in revisions for 2 (6.1%) patients. The mean follow-up length was 28.1 ± 6.1 months.

Conclusion

Fixed pressure shunts failed primarily because of shunt malfunction and occurred most commonly in patients developing hydrocephalus as a result of hemorrhage or normal pressure hydrocephalus (NPH). The overall failure rate between these two groups was proportionally equivalent. Both overdrainage or underdrainage were found to be rare indications for revision.

Neuroendoscopic lavage for the treatment of CSF infection with hydrocephalus in children

OBJECTIVE

The treatment of infectious CSF condition with ventriculitis and hydrocephalus in children is an interdisciplinary challenge. Conventional surgical treatment includes external ventricular drain (EVD) and systemic antibiotic therapy. However, infectious contamination of large ventricles combined with CSF protein overload often requires long treatment regimens. We retrospectively investigated neuroendoscopic lavage as a new option for clearance of CSF in children with hydrocephalus and active CSF infection.

PATIENTS AND METHODS

A database review identified 50 consecutive patients treated for CSF infection with hydrocephalus at our institution. Twenty-seven patients (control group, CG) were treated conventionally between 2004 and 2010, while 23 patients (neuroendoscopic group, NEG) underwent neuroendoscopic lavage for removal of intraventricular debris between 2010 and 2015. Clinical data, microbiology, laboratory measures, shunt dependency, and shunt revision rate were evaluated retrospectively.

RESULTS

The patient groups did not differ regarding basic clinical characteristics. Patients in NEG received neuroendoscopic lavage at mean of 1.6 ± 1times (1-4). No immediate postoperative complications were observed in NEG patients. Shunt rate in NEG patients was 91% as compared 100% in CG patients (p = 0.109). Within 24 months after shunt implantation, incidence of shunt revision was higher in CG (23/27) compared to NEG (5/23; p < 0.001). Reinfection was observed more often in CG (n = 17) compared to one patient in NEG (p < 0.001).

CONCLUSIONS

We experienced that neuroendoscopic lavage is a safe and effective treatment for hydrocephalus in children with infectious conditions. Neuroendoscopic lavage resulted in a decreased number of overall shunt revisions in shunt-depended patients as well as a lower number of recurrent infections.

Minimizing overdrainage with flow-regulated valves - Initial results of a prospective study on idiopathic normal pressure hydrocephalus

OBJECTIVE

Overdrainage and frequent reprogramming are common issues with programmable valves after ventriculoperitoneal shunt surgery for idiopathic normal pressure hydrocephalus (iNPH). Flow-regulated valves may address these limitations, but data on their efficacy are sparse. We present our single-center experience with flow-regulated valves focusing on overdrainage and efficiency.

PATIENTS AND METHODS

Thirty-two patients with iNPH treated with the Integra® NPH Low Flow Valve were prospectively enrolled. Clinical evaluation was performed at baseline, postoperatively as well as 3 and 6 months after surgery. The outcome was assessed by employing the iNPH grading scale and the Mini Mental Status Examination (MMSE). Overdrainage was assessed clinically and radiologically by computed tomography.

RESULTS

The mean patient age was 71 years. All patients presented with gait disturbance, 29 had cognitive impairment and 25 had urinary incontinence. The mean duration of symptoms was 22.9 months. At 3-month follow-up, 25/31 patients (80.6%) improved on the total iNPH score by at least 5 points (p < 0.001). The mean MMSE score increased from 24.5 to 26.1 points (p = 0.013). After 6 months, the improvement rates of the iNPH (82.1%) and the MMSE scores (26.8 points) were stable. The rate of clinically significant overdrainage was 3.2%. One patient presented with subdural hygromas that necessitated evacuation. In the remaining patients, clinical and radiological signs of overdrainage were absent.

CONCLUSION

The use of the Integra® NPH Low Flow Valve leads to a good neurological outcome and has low overdrainage rates without the need for reprogramming. These results are encouraging and justify further investigation of this valve.

Hydrocephalus treatment in children: long-term outcome in 975 consecutive patients

OBJECTIVE Hydrocephalus remains one of the more common pathologies managed in pediatric neurosurgical units. Endoscopic third ventriculostomy (ETV) has an advantage over ventriculoperitoneal shunting as it enables patients to remain device free. Multiple shunt devices with various valve designs exist, with no one valve proven to be superior to another. The aim of this study was to describe the management of hydrocephalus and its long-term outcome. METHODS The authors retrospectively reviewed the medical records of all patients who had been treated for hydrocephalus at the Hôpital Necker-Enfants Malades in the period from 1985 to 1995. RESULTS Nine hundred seventy-five children had been treated for hydrocephalus. The mean follow-up was 11 ± 7.4 years (mean ± standard deviation). The most common cause of hydrocephalus was tumor related (32.3%), followed by malformative (24.5%) and inflammatory (20.9%) causes. Two hundred eighty patients underwent ETV as the first-line treatment. The procedure was effective in controlling hydrocephalus due to posterior fossa tumors and aqueductal stenosis. Six hundred ninety-five children had initial shunt insertion, with the majority receiving an Orbis-Sigma valve (OSV). The overall OSV shunt survival was 70% at 1 year, 58% at 10 years, and 49% at 20 years. The most common cause for mechanical shunt failure was obstruction (50.7%). Overall shunt survival was statistically different between the OSV and the differential-pressure valve (p = 0.009). CONCLUSIONS Endoscopic third ventriculostomy is effective in the management of childhood hydrocephalus. Its success is directly related to the underlying pathology. In the long term, the OSV has significantly higher event-free shunt survival than the classic differential-pressure valve systems.

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.

Forty years of shunt surgery at Rigshospitalet, Denmark: a retrospective study comparing past and present rates and causes of revision and infection

OBJECTIVE

The objective of this study is to review our experience of shunt surgery by investigating 40 years of development in terms of rates of revision and infection, shunt survival and risk factors.

DESIGN AND PARTICIPANTS

Medical records and operative reports were reviewed retrospectively for all patients who underwent primary shunt surgery at our department in the years 2010 to 2012. All results were compared with a previous study from our department. A mixed population consisting of 434 patients was included. Adults (≥15 years) accounted for 89.9% of all patients and the mean follow-up time was 1.71 years.

RESULTS

Overall, 42.6% had a revision of which 65.4% fell within 6 months postoperatively. Low age, high-risk diagnoses and less severe brain injury were associated with a higher risk of revision. One and 5-year shunt survival probabilities were 66.2% (61.5-70.9) and 48.0% (41.1-54.9). Within 4 weeks postoperatively, 3.2% had an infection and overall infection rate was 5.5%. Short duration of surgery and the use of antibiotic prophylaxis were associated with a lower risk of infection. The most frequent causes of revision were valve defects (18.4%) and proximal defects or obstructions (15.7%). Compared to the previous study, no convincing improvement was found with regard to the revision rate (42.6% vs 48.3%, p 0.060) or overall infection rate (5.5% vs 7.4%, p 0.261).

CONCLUSIONS

Regardless of changes in patient demographics, techniques and equipment, risk of revision and infection still constitutes a major challenge in shunt surgery. The absence of convincing improvements calls for more studies concerning strategies to reduce complications.

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.

Ventriculoatrial Shunts in Adults, Incidence of Infection, and Significant Risk Factors: A Single-Center Experience

BACKGROUND

In recent years, the number of ventriculoatrial (VA) shunt insertions has decreased worldwide, the major cause being the risk of shunt infection. VA shunts remain as an alternative option to ventriculoperitoneal shunts. We describe our 10-year experience with VA shunts by analyzing the incidence of shunt infections and predisposing cofactors.

METHODS

During a median follow-up of 15.3 months, 259 shunt insertions, performed on 255 patients, were analyzed. The infection rate was calculated and the predisposing cofactors age, gender, cause of the hydrocephalus, previous external ventricle drainage, antibiotic-impregnated catheters, the number of revisions, the educational level of the surgeons, and the duration of the operations were analyzed. Two observation times were stratified.

RESULTS

We found overall infections in 18 patients (7.1%), 16 deep infections (6.3%) including 1 shunt nephritis (0.4%) and 2 superficial infections (0.8%). Wound dehiscence occurred in 17 patients (6. 6%). Analyzing follow-up time, the infection rate was 3.65% (95% confidence interval, 0.9%-5.9%) at survival time 1, 3.38% (95% confidence interval, 1.1%-6.2%) at survival time 2. In the first 6 months, 95% of patients were free of infection. Only the number of revision procedures was associated with the number of infections (P value < 0.0005).

CONCLUSIONS

In our patient cohort, the infection rate related to VA shunt insertion is low; the only statistically significant risk factor was the number of revisions. If the VA shunt is applied following a standardized protocol, the infection risk does not represent an argument for reluctance towards the VA draining concept.

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.

Performance of the fixed pressure valve with antisiphon device SPHERA® in the treatment of normal pressure hydrocephalus and prevention of overdrainage

Normal pressure hydrocephalus (NPH) is characterized by the triad of gait apraxia, dementia and urinary incontinence associated with ventriculomegaly and normal pressure of cerebrospinal fluid. Treatment is accomplished through the implantation of a ventricular shunt (VPS), however some complications are still frequent, like overdrainage due to siphon effect. This study analyses the performance of a valve with anti-siphon device (SPHERA®) in the treatment of patients with NPH and compares it with another group of patients with NPH who underwent the same procedure without anti-siphon mechanism (PS Medical® valve). 30 patients were consecutively enrolled in two groups with 15 patients each and followed clinically and radiologically for 1 year. Patients submitted to VPS with SPHERA® valve had the same clinical improvement as patients submitted to VPS with PS Medical®. However, complications and symptomatology due to overdrainage were significantly lower in SPHERA® group, suggesting it as a safe tool to treat NPH.

Relationship between ventricular size, white matter injury, and neurocognition in children with stable, treated hydrocephalus

OBJECT

Larger-than-normal ventricles can persist in children following hydrocephalus treatment, even if they are asymptomatic and clinically well. This study aims to answer the following question: do large ventricles result in brain injuries that are detectable on diffusion tensor imaging (DTI) and/or in measurable neurocognitive deficits in children with stable, treated hydrocephalus that are not seen in children with small ventricles?

METHODS

For this prospective study, we recruited 23 children (age range 8-18 years) with hydrocephalus due to aqueductal stenosis or tectal glioma who were asymptomatic following hydrocephalus treatment that had been performed at least 2 years earlier. All patients underwent detailed DTI and a full battery of neuropsychological tests. Correlation analysis was performed to assess the relationship between DTI parameters, neurocognitive tests, and ventricular size. The false-discovery rate method was used to adjust for multiple comparisons.

RESULTS

The median age of these 23 children at the time of assessment was 15.0 years (interquartile range [IQR] 12.1-17.6 years), and the median age at the first hydrocephalus treatment was 5.8 years (IQR 2.2 months-12.8 years). At the time of assessment, 17 children had undergone endoscopic third ventriculostomy and 6 children had received a shunt. After adjusting for multiple comparisons, there were no significant correlations between any neurocognitive test and ventricular volume, any DTI parameter and ventricular volume, or any DTI parameter and neurocognitive test.

CONCLUSIONS

Our data do not show an association between large ventricular size and additional white matter injury or worse neurocognitive deficits in asymptomatic children with stable, treated hydrocephalus caused by a discrete blockage of the cerebral aqueduct. Further investigations using larger patient samples are needed to validate these results.

Is there an ideal shunt? A panoramic view of 110 years in CSF diversions and shunt systems used for the treatment of hydrocephalus: from historical events to current trends

OBJECT

The goal of this study is to evaluate whether an "ideal shunt" exists.

METHODS

This is a retrospective analysis based on original papers in the field of Hydrocephalus and Shunts. Patients of all age groups, who had hydrocephalus, and underwent some form of CSF diversion were included. The study has been divided into four stages: from 1900 to 1949, 1950 to 1974, 1975 to 1999, and from 2000 to 2010.

RESULTS

In stage 1 (historical era): Saphenous vein grafts, rubber conduits, and other materials were used in CSF diversions. In 1949, the first implantable shunt tube was developed by Nulsen. In stage 2 (experimental stage): the Holter valve was developed. Newer innovations were developed in relation to the ventriculo-atrial shunt, which was the preferred CSF diversion. In stage 3 (developmental stage), a large number of different design shunt systems were developed, with the aim of reducing complications. The ventriculo-peritoneal shunt had become the preferred CSF diversion. Also, the programmable valve was born. In stage 4 (era of programmable valve, there is a preference for the use of programmable shunt systems. However, shunt failure rate at 1 year being around 25 to 40%, and shunt survival at 1 and 2 years are 50-70 and 47-53% in most series.

CONCLUSION

Every shunt is an ideal shunt provided the choice of the shunt used should be made by the matching performance of the shunt system to the altered profile of CSF dynamics of a given patient. The most important factor being the opening pressure.

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.

Thirty-day outcomes of cerebrospinal fluid shunt surgery: data from the National Surgical Quality Improvement Program-Pediatrics

OBJECT

Cerebrospinal fluid shunts are the mainstay of the treatment of hydrocephalus. In past studies, outcomes of shunt surgery have been analyzed based on follow-up of 1 year or longer. The goal of the current study is to characterize 30-day shunt outcomes, to identify clinical risk factors for shunt infection and failure, and to develop statistical models that might be used for risk stratification.

METHODS

Data for 2012 were obtained from the National Surgical Quality Improvement Program-Pediatrics (NSQIP-P) of the American College of Surgeons. Files with index surgical procedures for insertion or revision of a CSF shunt composed the study set. Returns to the operating room within 30 days for shunt infection and for shunt failure without infection were the study end points. Associations with a large number of potential clinical risk factors were analyzed on a univariate basis. Logistic regression was used for multivariate analysis.

RESULTS

There were 1790 index surgical procedures analyzed. The overall rates of shunt infection and shunt failure without infection were 2.0% and 11.5%, respectively. Male sex, steroid use in the preceding 30 days, and nutritional support at the time of surgery were risk factors for shunt infection. Cardiac disease was a risk factor for shunt failure without infection, and initial shunt insertion, admission during the second quarter, and neuromuscular disease appeared to be protective. There was a weak association of increasing age with shunt failure without infection. Models based on these factors accounted for no more than 6% of observed variance. Construction of stable statistical models with internal validity for risk adjustment proved impossible.

CONCLUSIONS

The precision of the NSQIP-P dataset has allowed identification of risk factors for shunt infection and for shunt failure without infection that have not been documented previously. Thirty-day shunt outcomes may be useful quality metrics, possibly even without risk adjustment. Whether important variation in 30-day outcomes exists among institutions or among neurosurgeons is yet unknown.

Overcoming CSF overdrainage with the adjustable gravitational valve proSA

BACKGROUND

Despite progress in shunt valve technology, CSF overdrainage is still one of the most frequent complications in shunt-treated hydrocephalus. Particularly with regard to young and adolescent patients, treatment of manifest overdrainage is complicated by several hardly influenceable factors such as increasing height and mobility. Therefore, the aim of this study was to evaluate the therapeutic efficiency of the new adjustable gravitational valve, proSA.

METHODS

Sixty-four shunt-treated young hydrocephalus patients aged 1.8-41.4 years (15.5 ± 10.5 years) suffering from clinical and/or radiological overdrainage underwent shunt revision surgery with the implantation of the new proSA valve. Clinical outcome after a 1-year follow-up period, pumping function of the valve chambers as well as the number of necessary postoperative valve adjustments were examined.

RESULTS

Fifty-five patients completed the study as planned. All reported a significant improvement of their clinical condition; 91 % described a complete resolution in symptoms related to overdrainage. Preoperatively, more than 85 % of the valve chambers showed no or very slow refilling with CSF. After a year of proSA treatment, more than 90 % exhibited a normal valve chamber function. During the follow-up period, a total of 136 valve adjustments were necessary. None of the proSA valves had to be surgically revised.

CONCLUSIONS

The postoperative adjustability of the opening pressure level is the advantage of the new gravitational valve. The good clinical outcome is attributed to the new valve technology. The proSA appears to be a promising shunt valve to overcome overdrainage in adolescent and adult hydrocephalus patients.

Outcomes of CSF shunting in children: comparison of Hydrocephalus Clinical Research Network cohort with historical controls: clinical article

OBJECT

The Hydrocephalus Clinical Research Network (HCRN), which comprises 7 pediatric neurosurgical centers in North America, provides a unique multicenter assessment of the current outcomes of CSF shunting in nonselected patients. The authors present the initial results for this cohort and compare them with results from prospective multicenter trials performed in the 1990s.

METHODS

Analysis was restricted to patients with newly diagnosed hydrocephalus undergoing shunting for the first time. Detailed perioperative data from 2008 through 2012 for all HCRN centers were prospectively collected and centrally stored by trained research coordinators. Historical control data were obtained from the Shunt Design Trial (1993-1995) and the Endoscopic Shunt Insertion Trial (1996-1999). The primary outcome was time to first shunt failure, which was determined by using Cox regression survival analysis.

RESULTS

Mean age of the 1184 patients in the HCRN cohort was older than mean age of the 720 patients in the historical cohort (2.51 years vs 1.60 years, p < 0.0001). The distribution of etiologies differed (p < 0.0001, chi-square test); more tumors and fewer myelomeningoceles caused the hydrocephalus in the HCRN cohort patients. The hazard ratio for first shunt failure significantly favored the HCRN cohort, even after the model was adjusted for the prognostic effects of age and etiology (adjusted HR 0.82, 95% CI 0.69-0.96).

CONCLUSIONS

Current outcomes of shunting in general pediatric neurosurgery practice have improved over those from the 1990s, although the reasons remain unclear.

[Treatment of hydrocephalus]

CLINICAL/METHODICAL ISSUE

Modern treatment of hydrocephalus. STANDARDS OF CLINICAL AND RADIOLOGICAL METHODS: Clinically: shunting and endoscopy. Radiologically: MRT, CCT.

METHODICAL INNOVATIONS

Important innovations are gravitational valves and neuroendoscopy standing for new challenges in preoperative imaging and for sufficient interpretation of postoperative imaging.

PERFORMANCE

G-valves reduce the complication rate (especially overdrainage) in shunting significantly. While lacking appropriated clinical studies, the UK Shunt Registry still provides the best comparison between shunting and neuroendoscopy, after which the long-term revision rates of both methods are identical. The perioperative risk of endoscopic surgery seems to be higher than for shunts.

ACHIEVEMENTS

The superiority of the G-valves in chronic hydrocephalus in comparison with other valves has recently been demonstrated in a class 1 evidence-based study. The neuroendoscopy, has been,-in the absence of a contraindications -, indicated by a guidelines' committee of the German Society of Neurosurgery as method of choice in occlusive hydrocephalus alternatively to shunting.

PRACTICAL RECOMMENDATIONS

Preoperatively, to clarify etiology, comorbidity, and surgical planning, MRI is preferable; with planned neuroendoscopy as high-resolution detailed MRI of access-trajectory and region of interest. In post-operative CT or MRI (after endoscopic procedures always MRI) a differentiation between (sub-)acute and chronic hydrocephalus is important for correct interpretation of imaging: a normalization of ventricular size is physiological only in (sub-)acute hydrocephalus, in chronic hydrocephalus, yet, sign of overdrainage. In chronic hydrocephalus, ventricles shrink usually only marginally. Solely, better delineated, vertex-near cisternae are there evidence of sufficient drainage.

Shunt survival rates by using the adjustable differential pressure valve combined with a gravitational unit (proGAV) in pediatric neurosurgery

OBJECT

Overdrainage is a chronic complication in shunted pediatric patients with hydrocephalus. The use of adjustability of differential pressure (DP) valves in combination with antisiphoning devices may help to overcome this sequela and may diminish the rate of possible shunt failures. The purpose of this retrospective study is to report our experience on shunt survival and infection rate with an adjustable DP valve with integrated gravitational unit in pediatric hydrocephalus.

METHODS

The proGAV consists of an adjustable differential pressure (DP) valve and a gravitational unit. During the time period of July 2004 and December 2009, a total of 237 adjustable gravitational valves were used in 203 children (age, 6.5 ± 6.54; 0-27 years). In the follow-up period, valve and shunt failures as well as rate of infection were recorded.

RESULTS

Within the average follow-up time of 21.9 ± 10.3 months (range, 6-72 months), the valve survival rate was 83.8 %. The overall shunt survival rate including all necessary revisions was 64.3 %. Looking at the group of infants (<1 year of age) within the cohort, the valve survival rate was 77.3 % and the shunt survival rate was 60.9 %. The overall infection rate was 4.6 %.

CONCLUSION

In a concept of avoiding chronic overdrainage by using the proGAV in hydrocephalic children, we observed a good rate of valve and shunt survival. Compared to previous reported series, we experienced the proGAV as a reliable tool for the treatment of pediatric hydrocephalus.

Patterns in neurosurgical adverse events: cerebrospinal fluid shunt surgery

Object

As part of a project to devise evidence-based safety interventions for specialty surgery, the authors sought to review current evidence in CSF shunt surgery concerning the frequency of adverse events in practice, their patterns, and the state of knowledge regarding methods for their reduction. This review may also inform future and ongoing efforts for the advancement of neurosurgical quality.

Methods

The authors performed a PubMed search using search terms “cerebral shunt,” “cerebrospinal fluid shunt,” “CSF shunt,” “ventriculoperitoneal shunt,” “cerebral shunt AND complications,” “cerebrospinal fluid shunt AND complications,” “CSF shunt AND complications,” and “ventriculoperitoneal shunt AND complications.” Only papers that specifically discussed the relevant complication rates were included. Papers were chosen to be included to maximize the range of rates of occurrence for the adverse events reported.

Results

In this review of the neurosurgery literature, the reported rate of mechanical malfunction ranged from 8% to 64%. The use of programmable valves has increased but remains of unproven benefit even in randomized trials. Infection was the second most common complication, with the rate ranging from 3% to 12% of shunt operations. A meta-analysis that included 17 randomized controlled trials of perioperative antibiotic prophylaxis demonstrated a decrease in shunt infection by half (OR 0.51, 95% CI 0.36–0.73). Similarly, use of detailed protocols including perioperative antibiotics, skin preparation, and limitation of OR personnel and operative time, among other steps, were shown in uncontrolled studies to decrease shunt infection by more than half.

Other adverse events included intraabdominal complications, with a reported incidence of 1% to 24%, intracerebral hemorrhage, reported to occur in 4% of cases, and perioperative epilepsy, with a reported association with shunt procedures ranging from 20% to 32%. Potential management strategies are reported but are largely without formal evaluation.

Conclusions

Surgery for CSF shunt placement or revision is associated with a high complication risk due primarily to mechanical issues and infection. Concerted efforts aimed at large-scale monitoring of neurosurgical complications and consistent quality improvement within these highlighted realms may significantly improve patient outcomes.

Pediatric hydrocephalus outcomes: a review

The outcome of pediatric hydrocephalus, including surgical complications, neurological sequelae and academic achievement, has been the matter of many studies. However, much uncertainty remains, regarding the very long-term and social outcome, and the determinants of complications and clinical outcome. In this paper, we review the different facets of outcome, including surgical outcome (shunt failure, infection and independence, and complications of endoscopy), clinical outcome (neurological, sensory, cognitive sequels, epilepsy), schooling and social integration. We then provide a brief review of the English-language literature and highlighting selected studies that provide information on the outcome and sequelae of pediatric hydrocephalus, and the impact of predictive variables on outcome. Mortality caused by hydrocephalus and its treatments is between 0 and 3%, depending on the duration of follow-up. Shunt event-free survival (EFS) is about 70% at one year and 40% at ten years. The EFS after endoscopic third ventriculostomy (ETV) appears better but likely benefits from selection bias and long-term figures are not available. Shunt infection affects between 5 and 8% of surgeries, and 15 to 30% of patients according to the duration of follow-up. Shunt independence can be achieved in 3 to 9% of patients, but the definition of this varies. Broad variations in the prevalence of cognitive sequelae, affecting 12 to 50% of children, and difficulties at school, affecting between 20 and 60%, attest of disparities among studies in their clinical evaluation. Epilepsy, affecting 6 to 30% of patients, has a serious impact on outcome. In adulthood, social integration is poor in a substantial number of patients but data are sparse. Few controlled prospective studies exist regarding hydrocephalus outcomes; in their absence, largely retrospective studies must be used to evaluate the long-term consequences of hydrocephalus and its treatments. This review aims to help to establish the current state of knowledge and to identify conflicting data and unanswered questions, in order to direct future studies.

The use of abdominal binders to treat over-shunting headaches

OBJECT

Headaches are common in children with shunts. Headaches associated with over-shunting are typically intermittent and tend to occur later in the day. Lying down frequently makes the headaches better. This paper examines the efficacy of using abdominal binders to treat over-shunting headaches.

METHODS

Over an 18-year period, the senior author monitored 1027 children with shunts. Office charts of 483 active patients were retrospectively reviewed to identify those children with headaches and, in particular, those children who were thought to have headaches as a result of over-shunting. Abdominal binders were frequently used to treat children with presumed over-shunting headaches, and these data were analyzed.

RESULTS

Of the 483 patients undergoing chart review, 258 (53.4%) had headache. A clinical diagnosis of over-shunting was made in 103 patients (21.3% overall; 39.9% of patients with headache). In 14 patients, the headaches were very mild (1-2 on a 5-point scale) and infrequent (1 or 2 per month), and treatment with an abdominal binder was not thought indicated. Eighty-nine patients were treated with a binder, but 19 were excluded from this retrospective study for noncompliance, interruption of the binder trial, or lack of follow-up. The remaining 70 pediatric patients, who were diagnosed with over-shunting headaches and were treated with abdominal binders, were the subjects of a more detailed retrospective study. Significant headache improvement was observed in 85.8% of patients. On average, the patients wore the binders for approximately 1 month, and headache relief usually persisted even after the binders were discontinued. However, the headaches eventually did recur in many of the patients more than a year later. In these patients, reuse of the abdominal binder was successful in relieving headaches in 78.9%.

CONCLUSIONS

The abdominal binder is an effective, noninvasive therapy to control over-shunting headaches in most children. This treatment should be tried before any surgery is considered. It is suggested that the abdominal binder may modulate abnormally increased intracranial pulse pressures associated with over-shunting. Interactions with the cerebrovascular bed are suspected to account for persistent headache relief after the binder is discontinued.

Antibiotic-impregnated shunt systems versus standard shunt systems: a meta- and cost-savings analysis

OBJECT

Infection is a serious and costly complication of CSF shunt implantation. Antibiotic-impregnated shunts (AISs) were introduced almost 10 years ago, but reports on their ability to decrease the infection rate have been mixed. The authors conducted a meta-analysis assessing the extent to which AISs reduce the rate of shunt infection compared with standard shunts (SSs). They also examined cost savings to determine the degree to which AISs could decrease infection-related hospital expenses.

METHODS

After conducting a comprehensive search of multiple electronic databases to identify studies that evaluated shunt type and used shunt-related infection as the primary outcome, 2 reviewers independently evaluated study quality based on preestablished criteria and extracted data. A random effects meta-analysis of eligible studies was then performed. For studies that demonstrated a positive effect with the AIS, a cost-savings analysis was conducted by calculating the number of implanted shunts needed to prevent a shunt infection, assuming an additional cost of $400 per AIS system and $50,000 to treat a shunt infection.

RESULTS

Thirteen prospective or retrospective controlled cohort studies provided Level III evidence, and 1 prospective randomized study provided Level II evidence. "Shunt infection" was generally uniformly defined among the studies, but the availability and detail of baseline demographic data for the control (SS) and treatment (AIS) groups within each study were variable. There were 390 infections (7.0%) in 5582 procedures in the control group and 120 infections (3.5%) in 3467 operations in the treatment group, yielding a pooled absolute risk reduction (ARR) and relative risk reduction (RRR) of 3.5% and 50%, respectively. The meta-analysis revealed the AIS to be statistically protective in all studies (risk ratio = 0.46, 95% CI 0.33-0.63) and in single-institution studies (risk ratio = 0.38, 95% CI 0.25-0.58). There was some evidence of heterogeneity when studies were analyzed together (p = 0.093), but this heterogeneity was reduced when the studies were analyzed separately as single institution versus multiinstitutional (p > 0.10 for both groups). Seven studies showed the AIS to be statistically protective against infection with an ARR and RRR ranging from 1.7% to 14.2% and 34% to 84%, respectively. The number of shunt operations requiring an AIS to prevent 1 shunt infection ranged from 7 to 59. Assuming 200 shunt cases per year, the annual savings for converting from SSs to AISs ranged from $90,000 to over $1.3 million.

CONCLUSIONS

While the authors recognized the inherent limitations in the quality and quantity of data available in the literature, this meta-analysis revealed a significant protective benefit with AIS systems, which translated into substantial hospital savings despite the added cost of an AIS. Using previously developed guidelines on treatment, the authors strongly encourage the use of AISs in all patients with hydrocephalus who require a shunt, particularly those at greatest risk for infection.

Shall we treat hydrocephalus associated to brain stem glioma in children?

PURPOSE/METHOD

Brain stem glioma accounts for 6-9% of brain tumors in children. Tumor progression may lead to CSF pathway obstruction and development of hydrocephalus. We retrospectively reviewed charts of patients consecutively treated in our institution with diffuse intrinsic pontine glioma in order to assess incidence of hydrocephalus, its management, and its impact on overall survival. All patients had brain stem glioma not amenable to surgery. Cases with exophytic brain stem glioma were excluded.

RESULTS

Fifty-one children were treated from January 2005 to December 2010 for brain stem glioma in the Pediatric Neurosurgery Department of Necker Enfants Malades, Paris, France. Hydrocephalus occurred in 11 of them (22%). They were six boys and five girls; the average and median time from tumor diagnosis to onset of hydrocephalus were 5.3 and 3.2 months, respectively, while average and median time from onset of hydrocephalus to death were 5.3 and 2.8 months, respectively. Hydrocephalus was treated in nine patients by a ventriculoperitoneal (VP) shunt and in two patients by an endoscopic third ventriculostomy. Because of early failure, a VP shunt was implanted in one child.

CONCLUSION

The overall 1-year survival rate was 33%. Survival rate of patients with such obstructive hydrocephalus was not significantly different from patients harboring brain stem glioma who did not develop hydrocephalus. Furthermore, hydrocephalus was not related to terminal tumor progression. Considering both risks and benefit of treatment, VP shunt could be proposed, on the base of our experience, as the first option in spite of the apparently obstructive nature of the hydrocephalus associated to a brain stem tumor.

Factors related to surgical outcome after posterior decompression and fusion for craniocervical junction lesions associated with osteogenesis imperfecta

Treatment for craniocervical junction lesions associated with osteogenesis imperfecta (OI) has been described, but there are divergent views on operative procedures and preoperative and postoperative therapies due to the small number of cases. It has been suggested that a major procedure such as combined anterior and posterior surgery with concomitant ventriculoperitoneal (VP) shunting is required for OI associated with basilar impression (BI). However, here we report a case with a good outcome after posterior decompression fusion only. The patient was a 29-year-old woman with OI (Sillence type-IA) who had neurological symptoms of vertigo, nausea, and shaking during walking. Diagnostic imaging revealed hydrocephalus, severe BI, and Chiari type-II malformation. Preoperative Halo traction led to improvement in symptoms, and posterior decompression fusion from the occipital bone to C6 was subsequently performed. Lateral mass screws and Nesplon cables as sublaminar wiring for reinforcement for fusion were used in the operation. The patient wore a Halo vest for 4 weeks postoperatively. She experienced no symptoms postoperatively. Bone fusion and improved hydrocephalus were clear on images at 3 years after surgery, and the postoperative course has been good. In craniocervical junction lesions associated with OI, instability with compression of the nerve and bone fragility in multiple sites can become problematic. Anterior odontoid resection and posterior fusion are required for OI with BI to give ideal decompression on images. However, the results of this case suggest that a good postoperative outcome can be achieved by performing not the combination of anterior odontoid resection and VP shunting, but only with posterior decompression fusion, especially for OI cases of Sillence type-I.

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.