Ten years of clinical experience in the use of fixed-pressure versus programmable valves: a retrospective study of 159 patients

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Ventriculoperitoneal shunt complications in an adult population: A comparison of various shunt designs to prevent overdrainage

Background:

Overdrainage after cerebrospinal fluid diversion remains a significant morbidity. The hydrostatic, gravitational force in the upright position can aggravate this. Siphon control (SC) mechanisms, as well as programmable and flow regulating devices, were developed to counteract this. However, limited studies have evaluated their safety and efficacy. In this study, direct comparisons of the complication rates between siphon control (SC) and non-SC (NSC), fixed versus programmable, and flow- versus pressure regulating valves are undertaken.

Methods:

A retrospective chart review was performed over all shunt implantations from January 2011 to December 2016 within the Houston Methodist Hospital system. Complication rates within 6 months of the operative date, including infection, subdural hematoma, malfunction, and any other shunt-related complication, were analyzed via Fisher’s exact test, with P < 0.05 regarded as significant. Subgroup analyses based on diagnoses – normal pressure hydrocephalus (HCP), pseudotumor cerebri, or other HCP – were also performed.

Results:

The overall shunt-related complication rate in this study was 19%. Overall rates of infection, shunt failure, and readmission within 180 days were 3%, 11%, and 34%, respectively. No difference was seen between SC and NSC groups in any complication rate overall or on subgroup analyses. When comparing fixed versus programmable and flow- versus pressure-regulating valves, the latter in each analysis had significantly lower malfunction and total complication rates.

Conclusions:

Programmable and pressure regulating devices may lead to lower shunt malfunction and total complication rates. Proper patient selection should guide valve choice. Future prospective studies may further elucidate the difference in complication rates between these various shunt designs.

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

OBJECTIVE

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

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary academic referral center.

PATIENTS

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

INTERVENTION

Cochlear implantation in the setting of a cerebrospinal fluid shunt.

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

A Cohort Comparison Analysis of Fixed Pressure Ventriculoperitoneal Shunt Valves With Programmable Valves for Hydrocephalus Following Nontraumatic Subarachnoid Hemorrhage

BACKGROUND

Hydrocephalus after nontraumatic subarachnoid hemorrhage (SAH) is a common sequela that may require the placement of ventriculoperitoneal shunts (VPS). Adjustable-pressure valves (APVs) are being widely used in this situation though more expensive than differential-pressure valves (DPVs).

OBJECTIVE

To compare outcomes between APV and DPV in SAH-induced hydrocephalus.

METHODS

We performed a retrospective chart review of patients with nontraumatic SAH who underwent VPS placement for the treatment of hydrocephalus after SAH, between July 2007 and December 2016. Patients were classified according to the type of valve (APV vs DPV). We evaluated factors that could predict the type of valve used, outcomes in VPS revision/replacement rate, and complications.

RESULTS

A total of 66 patients underwent VPS placement who were equally distributed into the 2 groups of valves. VPS failure with the need for revision/replacement occurred in 13 (19.7%) cases. Ten (30.3%) patients with DPV had a VPS failure, while 3 (9.1%) patients with an APV had a similar failure with the need for revision/replacement (P = .03). VPS placement before discharge during the initial hospitalization (P = .02) was statistically significant associated with the use of a DPV, while the reason of external ventricular drain (EVD) failure (P = .03) was associated with the use of an APV.

CONCLUSION

APVs had a lower rate of surgical revisions compared to DPVs. Early placement of VPS was associated with the use of a DPV. The need for EVD replacement due to EVD infection or malfunction was associated with higher rates of APV use.

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.

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.

Endoscopic third ventriculostomy for treatment of adult hydrocephalus: long-term follow-up of 163 patients

OBJECTIVE The efficacy of endoscopic third ventriculostomy (ETV) for the treatment of pediatric hydrocephalus has been extensively reported in the literature. However, ETV-related long-term outcome data are lacking for the adult hydrocephalus population. The objective of the present study was to assess the role of ETV as a primary or secondary treatment for hydrocephalus in adults. METHODS The authors performed a retrospective chart review of all adult patients (age ≥ 18 years) with symptomatic hydrocephalus treated with ETV in Calgary, Canada, over a span of 20 years (1994-2014). Patients were dichotomized into a primary or secondary ETV cohort based on whether ETV was the initial treatment modality for the hydrocephalus or if other CSF diversion procedures had been previously attempted respectively. Primary outcomes were subjective patient-reported clinical improvement within 12 weeks of surgery and the need for any CSF diversion procedures after the initial ETV during the span of the study. Categorical and actuarial data analysis was done to compare the outcomes of the primary versus secondary ETV cohorts. RESULTS A total of 163 adult patients with symptomatic hydrocephalus treated with ETV were identified and followed over an average of 98.6 months (range 0.1-230.4 months). All patients presented with signs of intracranial hypertension or other neurological symptoms. The primary ETV group consisted of 112 patients, and the secondary ETV consisted of 51 patients who presented with failed ventriculoperitoneal (VP) shunts. After the initial ETV procedure, clinical improvement was reported more frequently by patients in the primary cohort (87%) relative to those in the secondary ETV cohort (65%, p = 0.001). Additionally, patients in the primary ETV group required fewer reoperations (p < 0.001), with cumulative ETV survival time favoring this primary ETV cohort over the course of the follow-up period (p < 0.001). Fifteen patients required repeat ETV, with all but one experiencing successful relief of symptoms. Patients in the secondary ETV cohort also had a higher incidence of complications, with one occurring in 8 patients (16%) compared with 2 in the primary ETV group (2%; p = 0.010), although most complications were minor. CONCLUSIONS ETV is an effective long-term treatment for selected adult patients with hydrocephalus. The overall ETV success rate when it was the primary treatment modality for adult hydrocephalus was approximately 87%, and 99% of patients experience symptomatic improvement after 2 ETVs. Patients in whom VP shunt surgery fails prior to an ETV have a 22% relative risk of ETV failure and an almost eightfold complication rate, although mostly minor, when compared with patients who undergo a primary ETV. Most ETV failures occur within the first 7 months of surgery in patients treated with primary ETV, but the time to failure is more prolonged in patients who present with failed previous shunts.

Evidences in the treatment of idiopathic normal pressure hydrocephalus

INTRODUCTION

idiopathic normal pressure hydrocephalus (INPH) is characterized by gait apraxia, cognitive dysfunction and urinary incontinence. There are two main treatment options: ventriculoperitoneal shunt (VPS) and endoscopic third ventriculostomy (ETV). However, there are doubts about which modality is superior and what type of valve should be applied. We are summarizing the current evidence in INPH treatment.

METHODS

an electronic search of the literature was conducted on the Medline, Embase, Scielo and Lilacs databases from 1966 to the present to obtain data published about INPH treatment.

RESULTS

the treatment is based on three pillars: conservative, ETV and VPS. The conservative option has fallen into disuse after various studies showing good results after surgical intervention. ETV is an acceptable mode of treatment, but the superiority of VPS has made the latter the gold standard.

CONCLUSION

well-designed studies with a high level of appropriate evidence are still scarce, but the current gold standard for treatment of INPH is conducted using VPS.

Use of programmable versus nonprogrammable shunts in the management of hydrocephalus secondary to aneurysmal subarachnoid hemorrhage: a retrospective study with cost-benefit analysis

Object

The choice of programmable or nonprogrammable shunts for the management of hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) remains undefined. Variable intracranial pressures make optimal management difficult. Programmable shunts have been shown to reduce problems with drainage, but at 3 times the cost of nonprogrammable shunts.

Methods

All patients who underwent insertion of a ventriculoperitoneal shunt for hydrocephalus after aneurysmal SAH between 2006 and 2012 were included. Patients were divided into those in whom nonprogrammable shunts and those in whom programmable shunts were inserted. The rates of shunt revisions, the reasons for adjustments of shunt settings in patients with programmable devices, and the effectiveness of the adjustments were analyzed. A cost-benefit analysis was also conducted to determine if the overall cost for programmable shunts was more than for nonprogrammable shunts.

Results

Ninety-four patients underwent insertion of shunts for hydrocephalus secondary to SAH. In 37 of these patients, nonprogrammable shunts were inserted, whereas in 57 programmable shunts were inserted. Four (7%) of 57 patients with programmable devices underwent shunt revision, whereas 8 (21.6%) of 37 patients with nonprogrammable shunts underwent shunt revision (p = 0.0413), and 4 of these patients had programmable shunts inserted during shunt revision. In 33 of 57 patients with programmable shunts, adjustments were made. The adjustments were for a trial of functional improvement (n = 21), overdrainage (n = 5), underdrainage (n = 6), or overly sunken skull defect (n = 1). Of these 33 patients, 24 showed neurological improvements (p = 0.012). Cost-benefit analysis showed $646.60 savings (US dollars) per patient if programmable shunts were used, because the cost of shunt revision is a lot higher than the cost of the shunt.

Conclusions

The rate of shunt revision is lower in patients with programmable devices, and these are therefore more cost-effective. In addition, the shunt adjustments made for patients with programmable devices also resulted in better neurological outcomes.

The value of programmable shunt valves for the management of subdural collections in patients with hydrocephalus

Background. The aim of the present study was to assess the value of electromagnetic programmable shunt valves for the treatment of subdural collections. Methods. Adult patients with hydrocephalus of various causes that were treated with programmable shunt valves during the last ten years were retrospectively studied. In 127 patients, 139 electromagnetic programmable shunt valves were implanted. Results. A nontraumatic subdural fluid collection was detected in 12 patients. The treatment of these patients consisted of reprogramming of the valve's opening pressure. In 5 patients small subdural hematomas were detected; 4 of these patients were treated by raising the opening pressure alone and one patient required surgical drainage and change of the pressure setting. Traumatic chronic subdural hematomas were detected in 6 patients. These patients were treated by surgical drainage and readjustment of the valve's opening pressure. Conclusion. The ability to treat a shunt-related complication, such as a subdural fluid collection, by reprogramming the valve's opening pressure to a higher setting is an advantage over nonprogrammable valves, and it enables the opening pressure to be slowly lowered once the fluid collection is reabsorbed. Based on our results, we believe that programmable shunt valves should be preferred.

Programmable shunt valves for the treatment of hydrocephalus: a systematic review

OBJECTIVE

To evaluate the clinical effectiveness of programmable valves compared with non-programmable valves of hydrocephalus.

METHODS

In this paper, the authors report a systematic review and meta-analysis of complications and revision rate for programmable valves and non-programmable implantation. Randomized or non-randomized controlled trials of hydrocephalus treated by programmable and non-programmable valves were considered for inclusion.

RESULTS

Seven published reports of eligible studies involving 1702 participants meet the inclusion criteria. Compared with non-programmable, programmable valves had no significant difference in catheter-related complications [RR = 0.88, 95%CI (0.66,1.19), p = 0.10] and infection rate [RR = 1.25, 95%CI (0.92,1.69), p = 1.00]. There were significant differences in overall complications [RR = 0.80, 95%CI (0.67,0.96), p < 0.01], over-drainage or under-drainage complications [RR = 0.44, 95%CI (0.31,0.63), p < 0.01] and revision rate [RR = 0.56, 95%CI (0.45,0.69), p < 0.01] in favor of programmable valves.

CONCLUSION

Although the studies seem to demonstrate a small advantage for the programmable shunts, the probable bias and the difficulties in patient selection are too important to make a general conclusion.