Evaluating Shunt Survival Following Ventriculoperitoneal Shunting with and without Stereotactic Navigation in Previously Shunt-Naïve Patients

Ventriculoatrial Shunt Versus Ventriculoperitoneal Shunt: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Ventriculoperitoneal shunt (VPS) is usually the primary choice for cerebrospinal fluid shunting for most neurosurgeons, while ventriculoatrial shunt (VAS) is a second-line procedure because of historical complications. Remarkably, there is no robust evidence claiming the superiority of VPS over VAS. Thus, we aimed to compare both procedures through a meta-analysis.

METHODS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, the authors systematically searched the literature for articles comparing VAS with VPS. The included articles had to detail one of the following outcomes: revisions, infections, shunt-related mortality, or complications. In addition, the cohort for each shunt model had to encompass more than 4 patients.

RESULTS

Of 1872 articles, 16 met our criteria, involving 4304 patients, with 1619 undergoing VAS and 2685 receiving VPS placement. Analysis of revision surgeries showed no significant difference between VAS and VPS (risk ratio [RR] = 1.10, 95% CI: 0.9-1.34; I2 = 84%, random effects). Regarding infections, the analysis also found no significant difference between the groups (RR = 0.67, 95% CI: 0.36-1.25; I2 = 74%, random effects). There was no statistically significant disparity between both methods concerning shunt-related deaths (RR = 2.11, 95% CI: 0.68-6.60; I2 = 56%, random effects). Included studies after 2000 showed no VAS led to cardiopulmonary complications, and only 1 shunt-related death could be identified.

CONCLUSION

Both methods show no significant differences in procedure revisions, infections, and shunt-related mortality. The literature is outdated, research in adults is lacking, and future randomized studies are crucial to understand the profile of VAS when comparing it with VPS. The final decision on which distal site for cerebrospinal shunting to use should be based on the patient's characteristics and the surgeon's expertise.

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.

Endoscopic third ventriculostomy compared to ventriculoperitoneal shunt as treatment for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

BACKGROUND

The accepted treatment for idiopathic normal pressure hydrocephalus (iNPH) is the insertion of a ventriculoperitoneal shunt (VPS). Recently, some studies examined endoscopic third ventriculostomy (ETV) for the treatment of iNPH with controversial results. The aim of this systematic review and meta-analysis was to compare ETV to VPS regarding complications and outcome for the treatment of iNPH.

METHODS

We searched Medline, Embase and Scopus. Due to the scarcity of data, we did not include only randomized controlled trials, but also retro- and prospective studies. The primary outcome was failure of cerebrospinal fluid diversion method. Secondary endpoints were clinical postoperative improvement rate, morbidity and mortality.

RESULTS

Out of 311 screened studies, three were included in the quantitative analysis including one RCT and two retrospective cohort studies. No statistically significant difference concerning failure rate of CSF diversion method (ETV 27.5% vs. VPS 33.2%, RR 1.19, 95% CI [0.69-2.04], p = 0.52) or postoperative improvement was found (68% for ETV vs. 72.8% for VPS, RR 0.81, 95% CI [0.57-1.16], p = 0.26). ETV showed a significantly lower complication rate compared to VPS (7.5% vs. 51.1%, RR 0.25, 95% CI [0.08-0.76], p = 0.02).

CONCLUSION

ETV and VPS did not differ significantly regarding their failure rate for iNPH, while ETV showed a significantly lower complication rate than VPS. However, the data available is scarce with only one RCT investigating this important matter. Further well-designed trials are necessary to investigate the clinical outcome of ETV in iNPH.

TRIAL REGISTRATION NUMBER

PROSPERO (ID: CRD42020199173).

Complications Associated With Ventriculoperitoneal Shunt Surgery for Normal Pressure Hydrocephalus Using Stereotactic Navigation and Abdominal Laparoscopy: A Single-Institution Case Series

BACKGROUND

Normal pressure hydrocephalus (NPH) is characterized by cerebral ventriculomegaly and the triad of magnetic gait, urinary incontinence, and cognitive impairment. Treatment includes ventriculoperitoneal (VP) shunt surgery.

OBJECTIVE

To evaluate complication rates in a cohort of patients undergoing VP shunt surgery with stereotactic proximal catheter navigation and laparoscopic distal catheter placement.

METHODS

This study was a retrospective consecutive cohort analysis of 117 patients with NPH undergoing VP shunt placement using both stereotactic navigation and laparoscopy from 2015 to 2020. Patients with obstructive hydrocephalus and those with central nervous system infection, intraventricular hemorrhage, Ommaya reservoirs, or undergoing shunt revision at initial encounter were excluded. Variables included demographics and comorbidities, NPH symptoms, operative details, radiographic outcomes, and rates of complications, readmissions, and reoperations within 1, 3, and 12 months. Impact of demographics and comorbidities on complication rates was assessed using Fisher exact tests.

RESULTS

Zero patients required reoperation within 30 days. One intracranial hemorrhage was detected on immediate postoperative head computed tomography. Four patients ultimately required revision: 2 for catheter repositioning to alleviate abdominal pain, 1 ligation for a colectomy, and 1 removal for shunt infection. Patients with cardiac or other neurological comorbidities had higher rates of readmission and complications. Systemic complications totaled 12% in the first 30 days.

CONCLUSION

The combination of intraoperative stereotactic navigation and laparoscopic assistance leads to low rates of serious complications and reoperations for VP shunt implantation in patients with NPH. These changes to surgical technique are easy to implement and may reduce the risk for this common operation.

The effect of image-guided ventricular catheter placement on shunt failure: a systematic review and meta-analysis

INTRODUCTION

Cerebrospinal fluid (CSF) diversion for the treatment of hydrocephalus is one of the most common neurosurgical procedures. Over the years, the development of the neuronavigation system has allowed the surgeon to be guided in real time during the procedures. Nevertheless, to date, the revision rate remains as high as 30-40%. The aim of this study was to investigate the role of intraoperative image guidance in the prevention of shunt failure. We herein report the first literature meta-analysis of image guidance and shunt revision rate in the pediatric population.

METHODS

Principal online databases were searched for English-language articles published between January, 1980, and December, 2021. Analysis was limited to articles that included patients younger than 18 years of age at the time of primary V-P shunt. Articles reporting combined results of free-hand and image-guided placement of ventricular catheter (VC) were included. The main outcome measure of the study was the revision rate in relation to the intraoperative tools. Secondary variables collected were the age of the patient and ventricle size. Statistical analyses and meta-analysis plots were done via R and RStudio. Heterogeneity was formally assessed using Q, I², and τ² statistics. To examine publication bias was performed a funnel plot analysis.

RESULT

A total of 9 studies involving 2017 pediatric patients were included in the meta-analysis. 55.9% of procedures were carried out with the aid of intraoperative tools, while 44.1% procedures were conducted free hand. The intraoperative tools used were ultrasound (9.1%), electromagnetic neuronavigation (21.07%), endoscope (67.32%), and combined images (2.4%).The image-guided placement of VC was not statistically associated with a lower revision rate. The pooled OR was 0.97 [CI 95% 0.88-1.07] with an I² statistics of 34%, t² of 0.018 and a p-value of 0.15 at heterogeneity analysis.

CONCLUSION

Our analysis suggest images guidance during VC shunt placement does not statistically affect shunt survival. Nevertheless, intraoperative tools can support the surgeon especially in patients with difficult anatomy, slit ventricles or complex loculated hydrocephalus.

Practice Patterns of Ventriculoperitoneal Shunt Placement in Academic and Community Settings: A National Survey of Practicing Neurosurgeons

OBJECTIVE

We sought to assess the practice patterns of ventriculoperitoneal shunt (VPS) placement by neurosurgeons at academic, community, and government-based institutions.

METHODS

Using the American Association of Neurological Surgeons directory, a total of 3673 practicing neurosurgeons were contacted. The survey received 495 responses (57% academic, 41% community, 3% other/government based). The survey consisted of 9 questions to assess the frequency of general surgery assistance for distal VPS placement and the use of cranial neuronavigation for proximal placement and to assess subjective beliefs of personal practice pattern and the influence on shunt failure rates.

RESULTS

Almost half of the respondents reported using general surgery less than half of the time for distal VPS placement. Regardless of personal practice patterns, roughly one third of respondents reported that general surgery assistance is a common or somewhat common practice at their institution. The most common reasons for recruiting general surgery assistance were cases of higher complexity. Although commonly used, almost 40% of respondents believe that general surgery assistance does not decrease shunt failure rates. Cranial neuronavigation is used less than half of the time, and the most common reason was for improved accuracy. Almost half of the respondents believe navigation does decrease shunt failure rates.

CONCLUSIONS

General surgery assistance for distal placement and neuronavigation for the proximal placement of VPS catheters are both commonly used by neurosurgeons in academic, community, and other practice locations. This survey provides the first assessment of practice patterns nationally. The results demonstrate that roughly half of the practicing neurosurgeons use general surgery assistance and neuronavigation, particularly for complex or high-risk cases.

An integrated risk model stratifying seizure risk following brain tumor resection among seizure-naive patients without antiepileptic prophylaxis

OBJECTIVE

The natural history of seizure risk after brain tumor resection is not well understood. Identifying seizure-naive patients at highest risk for postoperative seizure events remains a clinical need. In this study, the authors sought to develop a predictive modeling strategy for anticipating postcraniotomy seizures after brain tumor resection.

METHODS

The IBM Watson Health MarketScan Claims Database was canvassed for antiepileptic drug (AED)– and seizure-naive patients who underwent brain tumor resection (2007–2016). The primary event of interest was short-term seizure risk (within 90 days postdischarge). The secondary event of interest was long-term seizure risk during the follow-up period. To model early-onset and long-term postdischarge seizure risk, a penalized logistic regression classifier and multivariable Cox regression model, respectively, were built, which integrated patient-, tumor-, and hospitalization-specific features. To compare empirical seizure rates, equally sized cohort tertiles were created and labeled as low risk, medium risk, and high risk.

RESULTS

Of 5470 patients, 983 (18.0%) had a postdischarge-coded seizure event. The integrated binary classification approach for predicting early-onset seizures outperformed models using feature subsets (area under the curve [AUC] = 0.751, hospitalization features only AUC = 0.667, patient features only AUC = 0.603, and tumor features only AUC = 0.694). Held-out validation patient cases that were predicted by the integrated model to have elevated short-term risk more frequently developed seizures within 90 days of discharge (24.1% high risk vs 3.8% low risk, p < 0.001). Compared with those in the low-risk tertile by the long-term seizure risk model, patients in the medium-risk and high-risk tertiles had 2.13 (95% CI 1.45–3.11) and 6.24 (95% CI 4.40–8.84) times higher long-term risk for postdischarge seizures. Only patients predicted as high risk developed status epilepticus within 90 days of discharge (1.7% high risk vs 0% low risk, p = 0.003).

CONCLUSIONS

The authors have presented a risk-stratified model that accurately predicted short- and long-term seizure risk in patients who underwent brain tumor resection, which may be used to stratify future study of postoperative AED prophylaxis in highest-risk patient subpopulations.

Predictive modeling of long-term opioid and benzodiazepine use after intradural tumor resection

BACKGROUND CONTEXT

Despite increased awareness of the ongoing opioid epidemic, opioid and benzodiazepine use remain high after spine surgery. In particular, long-term co-prescription of opioids and benzodiazepines have been linked to high risk of overdose-associated death. Tumor patients represent a unique subset of spine surgery patients and few studies have attempted to develop predictive models to anticipate long-term opioid and benzodiazepine use after spinal tumor resection.

METHODS

The IBM Watson Health MarketScan Database and Medicare Supplement were assessed to identify admissions for intradural tumor resection between 2007 and 2015. Adult patients were required to have at least 6 months of continuous preadmission baseline data and 12 months of continuous postdischarge follow-up. Primary outcomes were long-term opioid and benzodiazepine use, defined as at least 6 prescriptions within 12 months. Secondary outcomes were durations of opioid and benzodiazepine prescribing. Logistic regression models, with and without regularization, were trained on an 80% training sample and validated on the withheld 20%.

RESULTS

A total of 1,942 patients were identified. The majority of tumors were extramedullary (74.8%) and benign (62.5%). A minority of patients received arthrodesis (9.2%) and most patients were discharged to home (79.1%). Factors associated with postdischarge opioid use duration include tumor malignancy (vs benign, B=19.8 prescribed-days/year, 95% confidence interval [CI] 1.1-38.5) and intramedullary compartment (vs extramedullary, B=18.1 prescribed-days/year, 95% CI 3.3-32.9). Pre- and perioperative use of prescribed nonsteroidal anti-inflammatory drugs and gabapentin/pregabalin were associated with shorter and longer duration opioid use, respectively. History of opioid and history of benzodiazepine use were both associated with increased postdischarge opioid and benzodiazepine use. Intramedullary location was associated with longer duration postdischarge benzodiazepine use (B=10.3 prescribed-days/year, 95% CI 1.5-19.1). Among assessed models, elastic net regularization demonstrated best predictive performance in the withheld validation cohort when assessing both long-term opioid use (area under curve [AUC]=0.748) and long-term benzodiazepine use (AUC=0.704). Applying our model to the validation set, patients scored as low-risk demonstrated a 4.8% and 2.4% risk of long-term opioid and benzodiazepine use, respectively, compared to 35.2% and 11.1% of high-risk patients.

CONCLUSIONS

We developed and validated a parsimonious, predictive model to anticipate long-term opioid and benzodiazepine use early after intradural tumor resection, providing physicians opportunities to consider alternative pain management strategies.

Status epilepticus after intracranial neurosurgery: incidence and risk stratification by perioperative clinical features

OBJECTIVE

Status epilepticus (SE) is associated with significant mortality, cost, and risk of future seizures. In one of the first studies of SE after neurosurgery, the authors assess the incidence, risk factors, and outcome of postneurosurgical SE (PNSE).

METHODS

Neurosurgical admissions from the MarketScan Claims and Encounters database (2007 through 2015) were assessed in a longitudinal cross-sectional sample of privately insured patients who underwent qualifying cranial procedures in the US and were older than 18 years of age. The incidence of early (in-hospital) and late (postdischarge readmission) SE and associated mortality was assessed. Procedural, pathological, demographic, and anatomical covariates parameterized multivariable logistic regression and Cox models. Multivariable logistic regression and Cox proportional hazards models were used to study the incidence of early and late PNSE. A risk-stratification simulation was performed, combining individual predictors into singular risk estimates.

RESULTS

A total of 197,218 admissions (218,217 procedures) were identified. Early PNSE occurred during 637 (0.32%) of 197,218 admissions for cranial neurosurgical procedures. A total of 1045 (0.56%) cases of late PNSE were identified after 187,771 procedure admissions with nonhospice postdischarge follow-up. After correction for comorbidities, craniotomy for trauma, hematoma, or elevated intracranial pressure was associated with increased risk of early PNSE (adjusted OR [aOR] 1.538, 95% CI 1.183-1.999). Craniotomy for meningioma resection was associated with an increased risk of early PNSE compared with resection of metastases and parenchymal primary brain tumors (aOR 2.701, 95% CI 1.388-5.255). Craniotomies for infection or abscess (aHR 1.447, 95% CI 1.016-2.061) and CSF diversion (aHR 1.307, 95% CI 1.076-1.587) were associated with highest risk of late PNSE. Use of continuous electroencephalography in patients with early (p < 0.005) and late (p < 0.001) PNSE rose significantly over the study time period. The simulation regression model predicted that patients at high risk for early PNSE experienced a 1.10% event rate compared with those at low risk (0.07%). Similarly, patients predicted to be at highest risk for late PNSE were significantly more likely to eventually develop late PNSE than those at lowest risk (HR 54.16, 95% CI 24.99-104.80).

CONCLUSIONS

Occurrence of early and late PNSE was associated with discrete neurosurgical pathologies and increased mortality. These data provide a framework for prospective validation of clinical and perioperative risk factors and indicate patients for heightened diagnostic suspicion of PNSE.