A comparative result of ventriculoperitoneal shunt, focusing mainly on gravity-assisted valve and programmable valve

Long-term follow-up and comparison of programmable and non-programmable ventricular cerebrospinal fluid shunts among adult patients with different hydrocephalus etiologies: a retrospective cohort study

BACKGROUND

Programmable valve (PV) has been shown as a solution to the high revision rate in pediatric hydrocephalus patients, but it remains controversial among adults. This study is to compare the overall revision rate, revision cause, and revision-free survival between PV and non-programmable valve (NPV) in adult patients with different hydrocephalus etiologies.

METHOD

We reviewed the chart of all patients with hydrocephalus receiving index ventricular cerebrospinal fluid (CSF) shunt operations conducted at a single institution from January 2017 to December 2017. Patients included in the study were followed up for at least 5 years. Statistical tests including independent t-test, chi-square test, and Fisher's exact test were used for comparative analysis, and Kaplan-Meier curve using log-rank test was performed to compare the revision-free survival between the PV and NPV groups.

RESULTS

A total of 325 patients were included in the study, of which 181 patients were receiving PVs and 144 patients receiving NPV. There were 23 patients (12.8%) with PV and 22 patients (15.3%) with NPV receiving initial revision. No significant statistical difference in the initial revision rate was observed between the two groups (p = 0.52). No survival difference was found between the PV and NPV groups. However, better revision-free survival was noted in the PV group among idiopathic normal pressure hydrocephalus (iNPH) (p = 0.0274) and post-traumatic hydrocephalus (p = 0.017).

CONCLUSIONS

The combination of the different etiologies of hydrocephalus and the features of PV and NPV results in different outcomes-revision rate and revision-free survival. PV use might be superior to NPV in iNPH and post-traumatic hydrocephalus patients. Further studies are needed to clarify the indications of PV use in adult hydrocephalus patients.

Fixed versus Adjustable differential pressure valves in case of idiopathic normal pressure hydrocephalus treated with ventriculoperitoneal shunt. A systematic review and meta-analysis of proportion

INTRODUCTION

Idiopathic normal pressure hydrocephalus is a common cause of communicating hydrocephalus in adult age, presenting with classic Hakim-Adam's triad. Ventriculoperitoneal shunting is the treatment of choice in these cases. The main objective of this study is to compare the complication rate of Adjustable differential pressure valves with fixed differential pressure valves in these cases.

LITERATURE SEARCH

We systematically searched PubMed/Medline, Embase, LILACS, and ClinicalTrials.gov from their date of inception to 30th Jan 2023. We included observational studies, Randomized Controlled Trials (RCTs), and comparative and noncomparative studies in the search. The literature search resulted in 1394 studies, and only 22 studies were eligible to be included in the meta-analysis. We performed the meta-analysis of proportion to compare incidence rates by performing a Freeman-turkey double arcsine transformation.

RESULTS

The summary of the proportions of the incidence rate of complications was less for Adjustable Differential Pressure Valves (ADPV) as compared to Fixed Differential Pressure Valves (FDVP) but the confidence intervals overlapped. The summary proportion of surgical revision of shunt in the case of ADPV was 0.081 (95% CI (0.047, 0.115)), and in the case of FDPV was 0.173 (95% CI (0.047, 0.299)). Similarly, the summary proportion of subdural fluid collection in the case of ADPV was 0.090 (0.058, 0.122), and in the case of FDPV was 0.204 (0.132, 0.277). The incidence of complication was low in population implanted with DPV along with gravitational or anti-siphon unit (GASU).

CONCLUSION

Complication rates in the case of ADPV plus GASU were the lowest. Though the summary proportion of complication rate in the case of ADPV was low as compared to FDPV, the statistical significance of this difference is doubted due to overlapping confidence intervals.

How to define CSF overdrainage: a systematic literature review

PURPOSE

Overdrainage (OD) is one of the most frequent complications related to drainage of the cerebrospinal fluid (CSF). It is mostly associated with valve-bearing shunt systems but should probably be considered as a risk factor in any type of CSF diversion procedure. There is extreme variation in the reported incidence of OD due to the lack of consensus on defining criteria and an unclear perception of the pathophysiology. Hence, OD is probably underreported and underestimated. The objective of this paper was to establish a definition of OD, based on a systematic review of the literature.

METHODS

A systematic search was conducted in MEDLNE and EMBASE. Studies providing a definition or a description of diagnostic findings related to OD in ventriculoperitoneal shunt treated hydrocephalus were included. Non-English titles, abstracts and manuscripts were excluded. Extracted descriptions were graded into five groups (class I-V studies) based on how precise the terminology used to describe OD was. Class I studies were included for further analysis and characteristics of OD were extracted. The quality of included descriptions was assessed by a clinical expert panel.

RESULTS

A total of 1309 studies were screened, 190 were graded into groups, and 22, which provided specific definitions or descriptions of OD, were graded as class I studies. We extracted 32 different characteristics consistent with OD (e.g., clinical symptoms, radiological signs, and syndromes).

CONCLUSION

There was an overall agreement that CSF overdrainage following implantation of a ventriculoperitoneal shunt in a mixed pediatric and adult population is characterized as a persistent condition with clinically manifestations as postural dependent headache, nausea, and vomiting and/or radiological signs of slim ventricles and/or subdural collections.

Failure of Internal Cerebrospinal Fluid Shunt: A Systematic Review and Meta-Analysis of the Overall Prevalence in Adults

OBJECTIVE

Reported rates of failures of internal cerebrospinal fluid shunt (ICSFS) vary greatly from less than 5% to more than 50% and no meta-analysis to assess the overall prevalence has been performed. We estimated the failure rate after ICSFS insertion and searched for associated factors.

METHODS

Six databases were searched from January 1990 to February 2022. Only original articles reporting the rate of adult shunt failure were included. Random-effects meta-analysis with a generalized linear mixed model method and logit transformation was used to compute the overall failure prevalence. Subgroup analysis and meta-regression were implemented to search for associated factors.

RESULTS

Of 1763 identified articles, 46 were selected, comprising 70,859 ICSFS implantations and 13,603 shunt failures, suggesting an accumulated incidence of 19.2%. However, the calculated pooled prevalence value and its 95% confidence interval (CI) were 22.7% (95% CI, 19.8-5.8). The CI of the different estimates did not overlap, indicating a strong heterogeneity confirmed by a high I² of 97.5% (95% CI, 97.1-97.8; P < 0.001; τ² = 0.3). Ninety-five percent prediction interval of shunt failure prevalence ranged from 8.75% to 47.36%. A meta-regression of prevalence of publication found a barely significant decreasing failure rate of about 2% per year (-2.11; 95% CI, -4.02 to -0.2; P = 0.031).

CONCLUSIONS

Despite being a simple neurosurgical procedure, ICSFS insertion has one of the highest risk of complications, with failure prevalence involving more than 1 patient of 5. Nonetheless, all efforts to lower this high level of shunt failure seem to be effective.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Ventriculoperitoneal Shunting Surgery with Open Distal Shunt Catheter Placement in the Treatment of Hydrocephalus

Ventriculoperitoneal shunting (VPS) is a major therapy for hydrocephalus, but has a significant risk of device malfunctioning. In this study, we explored a novel distal shunt catheter placement method in VPS for the treatment of hydrocephalus. Five patients with different etiologies of hydrocephalus underwent VPS with open distant shunt catheter attached outside. We analyzed different variables (age, gender, medical history, clinical presentation, indication for surgery and surgical technique, postoperative complications) and occurrence of shunt failure and infection. All hydrocephalus patients who received the distal shunt catheter placed outside can undergo regular VPS again after the condition improves. The modified VPS in the treatment of hydrocephalus with the distal shunt catheter placed outside could potentially reduce the necessity of repeat surgery for addressing the complications caused by catheter obstruction and infections, reduce the chance of adhesions, and would be of benefit to those patients who need future revisions.

Analysis of the potential risk of central intravenous lines and/or total parenteral nutrition with ventriculoatrial shunts

OBJECT

The distal catheter of a ventriculoatrial (VA) cerebrospinal fluid shunt is potentially exposed to bacterial seeding from a subclavian central line. The risk of blood stream infections (BSIs) from central lines increases with administration of total parenteral nutrition (TPN). The potential risks of shunt malfunction or infection in patients with a VA shunt and a concurrent subclavian central line and/or TPN administration have not been studied.

METHODS

A retrospective review of 49 pediatric patients with placement of a VA shunt was performed. Three outcome measures were studied: shunt malfunction, shunt infection, and bacteremia/fungemia requiring shunt removal. All outcomes were measured by 1 year after shunt insertion. We analyzed the following potential risk factors: age at shunt insertion, prior ventriculoperitoneal (VP) shunt, prior shunt infection, abdominal infection/necrotizing enterocolitis (NEC), concurrent subclavian central line, and administration of TPN. The association between each risk factor and outcome was evaluated using Fisher's exact test to generate the relative risk. Additionally, a logistic regression analysis was performed to evaluate the odds ratio of the outcomes to risk factors considering age as a covariate.

RESULTS

The average age at shunt insertion was 6.3 ± 7.6 years. The most common diagnosis was posthemorrhagic hydrocephalus of prematurity (53.1 %). Fifteen patients (30.1 %) had a shunt malfunction within 1 year, 6 (12.2 %) had a shunt infection, and 3 (6.1 %) required removal of the shunt due to bacteremia/fungemia. The age at shunt insertion was not a statistically significant independent risk factor for any of the three outcomes. Prior shunt infection predicted an increased risk for both future shunt malfunction and infection in both the associative relative risk analysis and the age-dependent logistic regression analysis, although the correlation did not reach statistical significance. The presence of a subclavian central line or TPN administration did not statistically increase the risk over baseline for any of the outcomes in either analysis.

CONCLUSIONS

The relatively small number of patients limits the power of the study. Considering this limitation, the data suggests that the presence of a concurrent subclavian central line or administration of TPN does not increase the risk of shunt malfunction or infection over the baseline of this high-risk cohort.

Role of ventriculoperitoneal shunt valve design in the treatment of pediatric hydrocephalus--a single center study of valve performance in the clinical setting

PURPOSE

Previous studies have established risk factors for ventriculoperitoneal shunt failure in children. However, the role of valve type as a determinant of complications and outcome remains unclear. The aim of this study was to compare the fixed-pressure paediGAV and the programmable Codman Hakim valves in the clinical setting.

METHODS

We conducted a retrospective review of patients younger than 16 years who underwent primary implantation of a ventriculoperitoneal shunt with either valve type at our institution between January 2005 and December 2010. Shunt survival analyses were performed to identify variables associated with risk of shunt failure.

RESULTS

Of the 44 patients in the paediGAV cohort, 50% reached the endpoint of shunt failure with a mean time to shunt failure of 7 months. The Codman Hakim cohort comprised 29 patients, of which 55% experienced shunt failure with a mean time to shunt failure of 8 months. Stratified analyses identified young age at implantation and posthemorrhagic hydrocephalus as risk factors for shunt failure. Shunt survival analysis revealed no significant difference with regard to valve type.

CONCLUSIONS

This study confirmed important risk factors for shunt failure in children. Despite certain limitations and biases, similar findings for both valves examined in the clinical setting were obtained. Thus, valve type does not seem to influence risk of shunt failure. Prospective, randomized, and controlled trials are required to validate these results.

Shunt-responsive idiopathic normal pressure hydrocephalus patient with delayed improvement after tap test

The cerebrospinal fluid tap test (CSFTT) is recommended as a key step in the diagnosis of idiopathic normal pressure hydrocephalus (iNPH). While there is no generally accepted evaluation period for ascertaining a CSFTT responder, a substantial number of patients are evaluated only once within 24 hours of the test for improvement in gait. We report an iNPH patient with a favorable response to shunt surgery, who was first judged a non-responder by this standard, though subsequently was judged a responder in virtue of repetitively testing gait over 7 days. A 68-year-old man presented with progressive impairment of gait, balance, and memory. He was diagnosed as iNPH with an Evans' ratio of 0.35. At first hospitalization, change in gait was evaluated 24 hours after the CSFTT. He didn't show any significant improvement and was judged as a non-responder. However, at the second CSFTT, we repetitively tested his change in gait over seven days. Forty-eight hours after the tap, he showed significant improvement in his gait. He was then confirmed as a responder. After the operation, the gait difficulties were almost fully resolved. Further studies developing the standard procedure of the CSFTT should be considered.

The hydrokinetic parameters of shunts for hydrocephalus might be inadequate

Long-term treatment of hydrocephalus continues to be dismal. Shunting is the neurosurgical procedure more frequently associated with complications, which are mostly related with dysfunctions of the shunting device, rather than to mishaps of the rather simple surgical procedure. Overdrainage and underdrainage are the most common dysfunctions; of them, overdrainage is a conspicuous companion of most devices. Even when literally hundreds of different models have been proposed, developed, and tested, overdrainage has plagued all shunts for the last 60 years. Several investigations have demonstrated that changes in the posture of the subject induce unavoidable and drastic differences of intraventricular hydrokinetic pressure and cerebrospinal fluid (CSF) drainage through the shunt. Of all the parameters that participate in the pathophysiology of hydrocephalus, the only invariable one is cerebrospinal fluid production at a constant rate of approximately 0.35 ml/min. However, this feature has not been considered in the design of currently available shunts. Our experimental and clinical studies have shown that a simple shunt, whose drainage capacity complies with this unique parameter, would prevent most complications of shunting for hydrocephalus.