Conus-level combined dorsal and ventral lumbar rhizotomy for treatment of mixed hypertonia: technical note and complications

Combined dorsal and ventral rhizotomy is an effective treatment for patients with concurrent spasticity and dystonia, with the preponderance of complaints relating to their lower extremities. This operative approach provides definitive relief of hypertonia and should be considered after less-invasive techniques have been exhausted. Previously, the surgery has been described through an L1-S1 laminoplasty. In this series, 7 patients underwent a conus-level laminectomy for performing a lumbar dorsal and ventral rhizotomy. Technical challenges included identifying the appropriate-level ventral roots and performing the procedure in children with significant scoliosis. Techniques are described to overcome these obstacles. The technique was found to be safe, with no infections, CSF leaks, or neurogenic bladders.

Tracking the Volume of Neurosurgical Care During the Coronavirus Disease 2019 Pandemic

OBJECTIVE

In the present study, we quantified the effect of the coronavirus disease 2019 (COVID-19) on the volume of adult and pediatric neurosurgical procedures, inpatient consultations, and clinic visits at an academic medical center.

METHODS

Neurosurgical procedures, inpatient consultations, and outpatient appointments at Vanderbilt University Medical Center were identified from March 23, 2020 through May 8, 2020 (during COVID-19) and March 25, 2019 through May 10, 2019 (before COVID-19). The neurosurgical volume was compared between the 2 periods.

RESULTS

A 40% reduction in weekly procedural volume was demonstrated during COVID-19 (median before, 75; interquartile range [IQR], 72-80; median during, 45; IQR, 43-47; P < 0.001). A 42% reduction occurred in weekly adult procedures (median before, 62; IQR, 54-70; median during, 36; IQR, 34-39; P < 0.001), and a 31% reduction occurred in weekly pediatric procedures (median before, 13; IQR, 12-14; median during, 9; IQR, 8-10; P = 0.004). Among adult procedures, the most significant decreases were seen for spine (P < 0.001) and endovascular (P < 0.001) procedures and cranioplasty (P < 0.001). A significant change was not found in the adult open vascular (P = 0.291), functional (P = 0.263), cranial tumor (P = 0.143), or hydrocephalus (P = 0.173) procedural volume. Weekly inpatient consultations to neurosurgery decreased by 24% (median before, 99; IQR, 94-114; median during, 75; IQR, 68-84; P = 0.008) for adults. Weekly in-person adult and pediatric outpatient clinic visits witnessed a 91% decrease (median before, 329; IQR, 326-374; median during, 29; IQR, 26-39; P < 0.001). In contrast, weekly telehealth encounters increased from a median of 0 (IQR, 0-0) before to a median of 151 (IQR, 126-156) during COVID-19 (P < 0.001).

CONCLUSIONS

Significant reductions occurred in neurosurgical operations, clinic visits, and inpatient consultations during COVID-19. Telehealth was increasingly used for assessments. The long-term effects of the reduced neurosurgical volume and increased telehealth usage on patient outcomes should be explored.

Seizure-onset regions demonstrate high inward directed connectivity during resting-state: An SEEG study in focal epilepsy

OBJECTIVE

In patients with medically refractory focal epilepsy, stereotactic-electroencephalography (SEEG) can aid in localizing epileptogenic regions for surgical treatment. SEEG, however, requires long hospitalizations to record seizures, and ictal interpretation can be incomplete or inaccurate. Our recent work showed that non-directed resting-state analyses may identify brain regions as epileptogenic or uninvolved. Our present objective is to map epileptogenic networks in greater detail and more accurately identify seizure-onset regions using directed resting-state SEEG connectivity.

METHODS

In 25 patients with focal epilepsy who underwent SEEG, 2 minutes of resting-state, artifact-free, SEEG data were selected and functional connectivity was estimated. Using standard clinical interpretation, brain regions were classified into four categories: ictogenic, early propagation, irritative, or uninvolved. Three non-directed connectivity measures (mutual information [MI] strength, and imaginary coherence between and within regions) and four directed measures (partial directed coherence [PDC] and directed transfer function [DTF], inward and outward strength) were calculated. Logistic regression was used to generate a predictive model of ictogenicity.

RESULTS

Ictogenic regions had the highest and uninvolved regions had the lowest MI strength. Although both PDC and DTF inward strengths were highest in ictogenic regions, outward strengths did not differ among categories. A model incorporating directed and nondirected connectivity measures demonstrated an area under the receiver-operating characteristic (ROC) curve (AUC) of 0.88 in predicting ictogenicity of individual regions. The AUC of this model was 0.93 when restricted to patients with favorable postsurgical seizure outcomes.

SIGNIFICANCE

Directed connectivity measures may help identify epileptogenic networks without requiring ictal recordings. Greater inward but not outward connectivity in ictogenic regions at rest may represent broad inhibitory input to prevent seizure generation.

Patient and parental assessment of factors influencing the choice of treatment in pediatric hydrocephalus

OBJECTIVE

Choosing between competing options (shunt or endoscopic third ventriculostomy) for the management of hydrocephalus requires patients and caregivers to make a subjective judgment about the relative importance of risks and benefits associated with each treatment. In the context of this particular decision, little is known about what treatment-related factors are important and how they are prioritized in order to arrive at a treatment preference.

METHODS

The Hydrocephalus Association electronically distributed a survey to surgically treated hydrocephalus patients or their families. Respondents rated the importance of various surgical attributes in their decision-making about treatment choice, and also indicated their preference in hypothetical scenarios involving a trade-off between potential risks and benefits of treatment. Rank-order correlations were used to determine whether certain predictor variables affected the rating of factors or hypothetical treatment choice.

RESULTS

Eighty percent of 414 respondents rated procedural risks, minimizing repeat surgery, and improving long-term brain function as being very or extremely important factors when deciding on a treatment; 69% rated the need to implant a permanent device similarly. Parent-respondents rated procedural risks higher than patient-respondents. A majority of respondents (n = 209, 54%) chose a procedure with higher surgical risk if it meant that implantation of a permanent device was not required, and respondents were more likely to choose this option if they discussed both treatment options with their surgeon prior to their initial intervention (Spearman rho 0.198, p = 0.001).Although only 144 of 384 total respondents (38%) chose a less established operation if it meant less repeat surgery, patient-respondents were more likely to choose this option compared to parent-respondents (Spearman rho 0.145, p = 0.005). Likewise, patient-respondents were more likely than parent-respondents to choose an operation that involved less repeat surgery and led to worse long-term brain function (Spearman rho 0.160, p = 0.002), an option that was chosen by only 23 (6%) of respondents overall.

CONCLUSIONS

This study is the first exploration of patient/parental factors that influence treatment preference in pediatric hydrocephalus. Procedural risks, minimizing repeat operations, and the desire to maximize long-term cognitive function appeared to be the most important attributes that influenced treatment decisions that the survey respondents had made in the past. Patients and/or their caregivers appear to see some inherent benefit in being shunt free. It appears that fear of multiple revision operations may drive treatment choice in some circumstances.

Surgical resource utilization after initial treatment of infant hydrocephalus: comparing ETV, early experience of ETV with choroid plexus cauterization, and shunt insertion in the Hydrocephalus Clinical Research Network

OBJECTIVE

Few studies have addressed surgical resource utilization-surgical revisions and associated hospital admission days-following shunt insertion or endoscopic third ventriculostomy (ETV) with or without choroid plexus cauterization (CPC) for CSF diversion in hydrocephalus. Study members of the Hydrocephalus Clinical Research Network (HCRN) investigated differences in surgical resource utilization between CSF diversion strategies in hydrocephalus in infants.

METHODS

Patients up to corrected age 24 months undergoing initial definitive treatment of hydrocephalus were reviewed from the prospectively maintained HCRN Core Data Project (Hydrocephalus Registry). Postoperative courses (at 1, 3, and 5 years) were studied for hydrocephalus-related surgeries (primary outcome) and hospital admission days related to surgical revision (secondary outcome). Data were summarized using descriptive statistics and compared using negative binomial regression, controlling for age, hydrocephalus etiology, and HCRN center. The study population was organized into 3 groups (ETV alone, ETV with CPC, and CSF shunt insertion) during the 1st postoperative year and 2 groups (ETV alone and CSF shunt insertion) during subsequent years due to limited long-term follow-up data.

RESULTS

Among 1090 patients, the majority underwent CSF shunt insertion (CSF shunt, 83.5%; ETV with CPC, 10.0%; and ETV alone, 6.5%). Patients undergoing ETV with CPC had a higher mean number of revision surgeries (1.2 ± 1.6) than those undergoing ETV alone (0.6 ± 0.8) or CSF shunt insertion (0.7 ± 1.3) over the 1st year after surgery (p = 0.005). At long-term follow-up, patients undergoing ETV alone experienced a nonsignificant lower mean number of revision surgeries (0.7 ± 0.9 at 3 years and 0.8 ± 1.3 at 5 years) than those undergoing CSF shunt insertion (1.1 ± 1.9 at 3 years and 1.4 ± 2.6 at 5 years) and exhibited a lower mean number of hospital admission days related to revision surgery (3.8 ± 10.3 vs 9.9 ± 27.0, p = 0.042).

CONCLUSIONS

Among initial treatment strategies for hydrocephalus, ETV with CPC yielded a higher surgical revision rate within 1 year after surgery. Patients undergoing ETV alone exhibited a nonsignificant lower mean number of surgical revisions than CSF shunt insertion at 3 and 5 years postoperatively. Additionally, the ETV-alone cohort demonstrated significantly fewer hospital admission days related to surgical management of hydrocephalus within 3 years after surgery. These findings suggest a time-dependent benefit of ETV over CSF shunt insertion regarding surgical resource utilization.

Mechatronic Design of a Two-Arm Concentric Tube Robot System for Rigid Neuroendoscopy

Open surgical approaches are still often employed in neurosurgery, despite the availability of neuroendoscopic approaches that reduce invasiveness. The challenge of maneuvering instruments at the tip of the endoscope makes neuroendoscopy demanding for the physician. The only way to aim tools passed through endoscope ports is to tilt the entire endoscope; but, tilting compresses brain tissue through which the endoscope passes and can damage it. Concentric tube robots can provide necessary dexterity without endoscope tilting, while passing through existing ports in the endoscope and carrying surgical tools in their inner lumen. In this paper we describe the mechatronic design of a new concentric tube robot that can deploy two concentric tube manipulators through a standard neuroendoscope. The robot uses a compact differential drive and features embedded motor control electronics and redundant position sensors for safety. In addition to the mechatronic design of this system, this paper contributes experimental validation in the context of colloid cyst removal, comparing our new robotic system to standard manual endoscopy in a brain phantom. The robotic approach essentially eliminated endoscope tilt during the procedure (17.09° for the manual approach vs. 1.16° for the robotic system). The robotic system also enables a single surgeon to perform the procedure - typically in a manual approach one surgeon aims the endoscope and another operates the tools delivered through its ports.

Association between supratentorial pediatric high-grade gliomas involved with the subventricular zone and decreased survival: a multi-institutional retrospective study

OBJECTIVE

The subventricular zone (SVZ), housed in the lateral walls of the lateral ventricles, is the largest neurogenic niche in the brain. In adults, high-grade gliomas in contact or involved with the SVZ are associated with decreased survival. Whether this association holds true in the pediatric population remains unexplored. To address this gap in knowledge, the authors conducted this retrospective study in a pediatric population with high-grade gliomas treated at three comprehensive centers in the United States.

METHODS

The authors retrospectively identified 63 patients, age ≤ 21 years, with supratentorial WHO grade III-IV gliomas treated at three academic centers. Basic demographic and clinical data regarding presenting signs and symptoms and common treatment variables were obtained. Preoperative MRI studies were evaluated to assess SVZ contact by tumor and to quantify tumor volume.

RESULTS

Sixty-three patients, including 34 males (54%), had a median age of 12.3 years (IQR 6.50-16.2) and a median tumor volume of 39.4 ml (IQR 19.4-65.8). Tumors contacting the SVZ (SVZ+) were noted in 34 patients (54%) and overall were larger than those not in contact with the SVZ (SVZ-; 51.1 vs 27.3, p = 0.002). The SVZ+ tumors were also associated with decreased survival. However, age, tumor volume, tumor grade, and treatment with chemotherapy and/or radiation were not associated with survival in the 63 patients. In the univariable analysis, near-total resection, gross-total resection, and seizure presentation were associated with increased survival (HR = 0.23, 95% CI 0.06-0.88, p = 0.03; HR = 0.26, 95% CI 0.09-0.74, p = 0.01; and HR = 0.46, 95% CI 0.22-0.97, p = 0.04, respectively). In a multivariable stepwise Cox regression analysis, only SVZ+ tumors remained significantly associated with decreased survival (HR = 1.94, 95% CI 1.03-3.64, p = 0.04).

CONCLUSIONS

High-grade glioma contact with the SVZ neural stem cell niche was associated with a significant decrease in survival in the pediatric population, as it is in the adult population. This result suggests that tumor contact with the SVZ is a general negative prognosticator in high-grade glioma independent of age group and invites biological investigations to understand the SVZ's role in glioma pathobiology.

Transcriptional analyses of adult and pediatric adamantinomatous craniopharyngioma reveals similar expression signatures regarding potential therapeutic targets

Adamantinomatous craniopharyngioma (ACP) is a biologically benign but clinically aggressive lesion that has a significant impact on quality of life. The incidence of the disease has a bimodal distribution, with peaks occurring in children and older adults. Our group previously published the results of a transcriptome analysis of pediatric ACPs that identified several genes that were consistently overexpressed relative to other pediatric brain tumors and normal tissue. We now present the results of a transcriptome analysis comparing pediatric to adult ACP to identify biological differences between these groups that may provide novel therapeutic insights or support the assertion that potential therapies identified through the study of pediatric ACP may also have a role in adult ACP. Using our compiled transcriptome dataset of 27 pediatric and 9 adult ACPs, obtained through the Advancing Treatment for Pediatric Craniopharyngioma Consortium, we interrogated potential age-related transcriptional differences using several rigorous mathematical analyses. These included: canonical differential expression analysis; divisive, agglomerative, and probabilistic based hierarchical clustering; information theory based characterizations; and the deep learning approach, HD Spot. Our work indicates that there is no therapeutically relevant difference in ACP gene expression based on age. As such, potential therapeutic targets identified in pediatric ACP are also likely to have relvance for adult patients.

Cerebrospinal fluid alterations following endoscopic third ventriculostomy with choroid plexus cauterization: a retrospective laboratory analysis of two tertiary care centers

PURPOSE

This study sought to determine the previously undescribed cytologic and metabolic alterations that accompany endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC).

METHODS

Cerebrospinal fluid (CSF) samples were collected from infant patients with hydrocephalus at the time of index ETV/CPC and again at each reintervention for persistent hydrocephalus. Basic CSF parameters, including glucose, protein, and cell counts, were documented. A multivariable regression model, incorporating known predictors of ETV/CPC outcome, was constructed for each parameter to inform time-dependent normative values.

RESULTS

A total of 187 infants were treated via ETV/CPC for hydrocephalus; initial laboratory values were available for 164 patients. Etiology of hydrocephalus included myelomeningocele (53, 32%), intraventricular hemorrhage of prematurity (43, 26%), aqueductal stenosis (24, 15%), and others (44, 27%). CSF parameters did not differ significantly with age or etiology. Glucose levels initially drop below population average (36 to 32 mg/dL) post-operatively before slowly rising to normal levels (42 mg/dL) by 3 months. Dramatically elevated protein levels post-ETV/CPC (baseline of 59 mg/dL up to roughly 200 mg/dL at 1 month) also normalized over 3 months. No significant changes were appreciated in WBC. RBC counts were very elevated following ETV/CPC and quickly declined over the subsequent month.

CONCLUSION

CSF glucose and protein deviate significantly from normal ranges following ETV/CPC before normalizing over 3 months. High RBC values immediately post-ETV/CPC decline rapidly. Age at time of procedure and etiology have little influence on common clinical CSF laboratory parameters. Of note, the retrospective study design necessitates ETV/CPC failure, which could introduce bias in the results.

Timing of syrinx reduction and stabilization after posterior fossa decompression for pediatric Chiari malformation type I

OBJECTIVE

The aim of this study was to determine the timeline of syrinx regression and to identify factors mitigating syrinx resolution in pediatric patients with Chiari malformation type I (CM-I) undergoing posterior fossa decompression (PFD).

METHODS

The authors conducted a retrospective review of records from pediatric patients (< 18 years old) undergoing PFD for the treatment of CM-I/syringomyelia (SM) between 1998 and 2015. Patient demographic, clinical, radiological, and surgical variables were collected and analyzed. Radiological information was reviewed at 4 time points: 1) pre-PFD, 2) within 6 months post-PFD, 3) within 12 months post-PFD, and 4) at maximum available follow-up. Syrinx regression was defined as ≥ 50% decrease in the maximal anteroposterior syrinx diameter (MSD). The time to syrinx regression was determined using Kaplan-Meier analysis. Multivariate analysis was conducted using a Cox proportional hazards model to determine the association between preoperative, clinical, and surgery-related factors and syrinx regression.

RESULTS

The authors identified 85 patients with CM-I/SM who underwent PFD. Within 3 months post-PFD, the mean MSD regressed from 8.1 ± 3.4 mm (preoperatively) to 5.6 ± 2.9 mm within 3 months post-PFD. Seventy patients (82.4%) achieved ≥ 50% regression in MSD. The median time to ≥ 50% regression in MSD was 8 months (95% CI 4.2-11.8 months). Using a risk-adjusted multivariable Cox proportional hazards model, the patients who underwent tonsil coagulation (n = 20) had a higher likelihood of achieving ≥ 50% syrinx regression in a shorter time (HR 2.86, 95% CI 1.2-6.9; p = 0.02). Thirty-six (75%) of 45 patients had improvement in headache at 2.9 months (IQR 1.5-4.4 months).

CONCLUSIONS

The maximum reduction in syrinx size can be expected within 3 months after PFD for patients with CM-I and a syrinx; however, the syringes continue to regress over time. Tonsil coagulation was associated with early syrinx regression in this cohort. However, the role of surgical maneuvers such as tonsil coagulation and arachnoid veil identification and sectioning in the overall role of CM-I surgery remains unclear.

The Preventable Shunt Revision Rate: A Multicenter Evaluation

BACKGROUND

The Preventable Shunt Revision Rate (PSRR) was recently introduced as a novel quality metric.

OBJECTIVE

To evaluate the PSRR across multiple centers and determine associated variables.

METHODS

Nine participating centers in North America provided at least 2 years of consecutive shunt operations. Index surgery was defined as new shunt implantation, or revision of an existing shunt. For any index surgery that resulted in a reoperation within 90-days, index surgery information (demographic, clinical, and procedural) was collected and a decision made whether the failure was potentially preventable. The 90-day shunt failure rate and PSRR were calculated per institution and combined. Bivariate analyses were performed to evaluate individual effects of each independent variable on preventable shunt failure followed by a final multivariable model using a backward model selection approach.

RESULTS

A total of 5092 shunt operations were performed; 861 failed within 90 days of index operation, resulting in a 16.9% combined 90-day shunt failure rate and 17.6% median failure rate (range, 8.7%-26.9%). Of the failures, 307 were potentially preventable (overall and median 90-day PSRR, 35.7% and 33.9%, respectively; range, 16.1%-55.4%). The most common etiologies of avoidable failure were infection (n = 134, 44%) and proximal catheter malposition (n = 83, 27%). Independent predictors of preventable failure (P < .05) were lack of endoscopy (odds ratio [OR] = 2.26), recent shunt infection (OR = 3.65), shunt type (OR = 2.06) and center.

CONCLUSION

PSRR is variable across institutions, but can be 50% or higher. While the PSRR may never reach zero, this study demonstrates that overall about a third of early failures are potentially preventable.

Graft dural closure is associated with a reduction in CSF leak and hydrocephalus in pediatric patients undergoing posterior fossa brain tumor resection

OBJECTIVE

The authors aimed to evaluate clinical, radiological, and surgical factors associated with posterior fossa tumor resection (PFTR)-related outcomes, including postoperative complications related to dural augmentation (CSF leak and wound infection), persistent hydrocephalus ultimately requiring permanent CSF diversion after PFTR, and 90-day readmission rate.

METHODS

Pediatric patients (0-17 years old) undergoing PFTR between 2000 and 2016 at Monroe Carell Jr. Children's Hospital of Vanderbilt University were retrospectively reviewed. Descriptive statistics included the Wilcoxon signed-rank test to compare means that were nonnormally distributed and the chi-square test for categorical variables. Variables that were nominally associated (p < 0.05) with each outcome by univariate analysis were included as covariates in multivariate linear regression models. Statistical significance was set a priori at p < 0.05.

RESULTS

The cohort consisted of 186 patients with a median age at surgery of 6.62 years (range 3.37-11.78 years), 55% male, 83% Caucasian, and average length of follow-up of 3.87 ± 0.25 years. By multivariate logistic regression, the variables primary dural closure (PDC; odds ratio [OR] 8.33, 95% confidence interval [CI] 1.07-100, p = 0.04), pseudomeningocele (OR 7.43, 95% CI 2.23-23.76, p = 0.0007), and hydrocephalus ultimately requiring permanent CSF diversion within 90 days of PFTR (OR 9.25, 95% CI 2.74-31.2, p = 0.0003) were independently associated with CSF leak. PDC versus graft dural closure (GDC; 35% vs 7%, OR 5.88, 95% CI 2.94-50.0, p = 0.03) and hydrocephalus ultimately requiring permanent CSF diversion (OR 3.30, 95% CI 1.07-10.19, p = 0.0007) were associated with wound infection requiring surgical debridement. By multivariate logistic regression, GDC versus PDC (23% vs 37%, OR 0.13, 95% CI 0.02-0.87, p = 0.04) was associated with persistent hydrocephalus ultimately requiring permanent CSF diversion, whereas pre- or post-PFTR ventricular size, placement of peri- or intraoperative extraventricular drain (EVD), and radiation therapy were not. Furthermore, the addition of perioperative EVD placement and dural closure method to a previously validated predictive model of post-PFTR hydrocephalus improved its performance from area under the receiver operating characteristic curve of 0.69 to 0.74. Lastly, the authors found that autologous (vs synthetic) grafts may be protective against persistent hydrocephalus (p = 0.02), but not CSF leak, pseudomeningocele, or wound infection.

CONCLUSIONS

These results suggest that GDC, independent of potential confounding factors, may be protective against CSF leak, wound infection, and hydrocephalus in patients undergoing PFTR. Additional studies are warranted to further evaluate clinical and surgical factors impacting PFTR-associated complications.

Stereotactic EEG via multiple single-path omnidirectional trajectories within a single platform: institutional experience with a novel technique

OBJECTIVEStereotactic electroencephalography (SEEG) is being used with increasing frequency to interrogate subcortical, cortical, and multifocal epileptic foci. The authors describe a novel technique for SEEG in patients with suspected epileptic foci refractory to medical management.METHODSIn the authors' technique, standard epilepsy evaluation and neuroimaging are used to create a hypothesis-driven SEEG plan, which informs the 3D printing of a novel single-path, multiple-trajectory, omnidirectional platform. Following skull-anchor platform fixation, electrodes are sequentially inserted according to the preoperative plan. The authors describe their surgical experience and technique based on a review of all cases, adult and pediatric, in which patients underwent invasive epilepsy monitoring via SEEG during an 18-month period at Vanderbilt University Medical Center. Platform and anatomical variables influencing localization error were evaluated using multivariate linear regression.RESULTSUsing this novel technology, 137 electrodes were inserted in 15 patients with focal epilepsy with favorable recording results and no clinical complications. The mean entry point localization error was 1.42 mm (SD 0.98 mm), and the mean target point localization error was 3.36 mm (SD 2.68 mm). Platform distance, electrode trajectory angle, and intracranial distance, but not skull thickness, were independently associated with localization error.CONCLUSIONSThe multiple-trajectory, single-path, omnidirectional platform offers satisfactory accuracy and favorable clinical results, while avoiding cumbersome frames and prohibitive up-front costs associated with other SEEG technologies.

Predictors of success for combined endoscopic third ventriculostomy and choroid plexus cauterization in a North American setting: a Hydrocephalus Clinical Research Network study

OBJECTIVE

Endoscopic third ventriculostomy combined with choroid plexus cauterization (ETV+CPC) has been adopted by many pediatric neurosurgeons as an alternative to placing shunts in infants with hydrocephalus. However, reported success rates have been highly variable, which may be secondary to patient selection, operative technique, and/or surgeon training. The objective of this prospective multicenter cohort study was to identify independent patient selection, operative technique, or surgical training predictors of ETV+CPC success in infants.

METHODS

This was a prospective cohort study nested within the Hydrocephalus Clinical Research Network's (HCRN) Core Data Project (registry). All infants under the age of 2 years who underwent a first ETV+CPC between June 2006 and March 2015 from 8 HCRN centers were included. Each patient had a minimum of 6 months of follow-up unless censored by an ETV+CPC failure. Patient and operative risk factors of failure were examined, as well as formal ETV+CPC training, which was defined as traveling to and working with the experienced surgeons at CURE Children's Hospital of Uganda. ETV+CPC failure was defined as the need for repeat ETV, shunting, or death.

RESULTS

The study contained 191 patients with a primary ETV+CPC conducted by 17 pediatric neurosurgeons within the HCRN. Infants under 6 months corrected age at the time of ETV+CPC represented 79% of the cohort. Myelomeningocele (26%), intraventricular hemorrhage associated with prematurity (24%), and aqueductal stenosis (17%) were the most common etiologies. A total of 115 (60%) of the ETV+CPCs were conducted by surgeons after formal training. Overall, ETV+CPC was successful in 48%, 46%, and 45% of infants at 6 months, 1 year, and 18 months, respectively. Young age (< 1 month) (adjusted hazard ratio [aHR] 1.9, 95% CI 1.0-3.6) and an etiology of post-intraventricular hemorrhage secondary to prematurity (aHR 2.0, 95% CI 1.1-3.6) were the only two independent predictors of ETV+CPC failure. Specific subgroups of ages within etiology categories were identified as having higher ETV+CPC success rates. Although training led to more frequent use of the flexible scope (p < 0.001) and higher rates of complete (> 90%) CPC (p < 0.001), training itself was not independently associated (aHR 1.1, 95% CI 0.7-1.8; p = 0.63) with ETV+CPC success.

CONCLUSIONS

This is the largest prospective multicenter North American study to date examining ETV+CPC. Formal ETV+CPC training was not found to be associated with improved procedure outcomes. Specific subgroups of ages within specific hydrocephalus etiologies were identified that may preferentially benefit from ETV+CPC.

Predictors of endoscopic third ventriculostomy ostomy status in patients who experience failure of endoscopic third ventriculostomy with choroid plexus cauterization

OBJECTIVE

At failure of endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC), the ETV ostomy may be found to be closed or open. Failure with a closed ostomy may indicate a population that could benefit from evolving techniques to keep the ostomy open and may be candidates for repeat ETV, whereas failure with an open ostomy may be due to persistently abnormal CSF dynamics. This study seeks to identify clinical and radiographic predictors of ostomy status at the time of ETV/CPC failure.

METHODS

The authors conducted a multicenter, retrospective cohort study on all pediatric patients with hydrocephalus who failed initial ETV/CPC treatment between January 2013 and October 2016. Failure was defined as the need for repeat ETV or ventriculoperitoneal (VP) shunt placement. Clinical and radiographic data were collected, and ETV ostomy status was determined endoscopically at the subsequent hydrocephalus procedure. Statistical analysis included the Mann-Whitney U-test, Wilcoxon rank-sum test, t-test, and Pearson chi-square test where appropriate, as well as multivariate logistic regression.

RESULTS

Of 72 ETV/CPC failures, 28 patients (39%) had open-ostomy failure and 44 (61%) had closed-ostomy failure. Patients with open-ostomy failure were older (median 5.1 weeks corrected age for gestation [interquartile range (IQR) 0.9-15.9 weeks]) than patients with closed-ostomy failure (median 0.2 weeks [IQR -1.3 to 4.5 weeks]), a significant difference by univariate and multivariate regression. Etiologies of hydrocephalus included intraventricular hemorrhage of prematurity (32%), myelomeningocele (29%), congenital communicating (11%), aqueductal stenosis (11%), cyst/tumor (4%), and other causes (12%). A wider baseline third ventricle was associated with open-ostomy failure (median 15.0 mm [IQR 10.3-18.5 mm]) compared to closed-ostomy failure (median 11.7 mm [IQR 8.9-16.5 mm], p = 0.048). Finally, at the time of failure, patients with closed-ostomy failure had enlargement of their ventricles (frontal and occipital horn ratio [FOHR], failure vs baseline, median 0.06 [IQR 0.00-0.11]), while patients with open-ostomy failure had no change in ventricle size (median 0.01 [IQR -0.04 to 0.05], p = 0.018). Previous CSF temporizing procedures, intraoperative bleeding, and time to failure were not associated with ostomy status at ETV/CPC failure.

CONCLUSIONS

Older corrected age for gestation, larger baseline third ventricle width, and no change in FOHR were associated with open-ostomy ETV/CPC failure. Future studies are warranted to further define and confirm features that may be predictive of ostomy status at the time of ETV/CPC failure.

Incidence of Epilepsy and Associated Risk Factors in Perinatal Ischemic Stroke Survivors

INTRODUCTION

Epilepsy is a serious and often lifelong consequence of perinatal arterial ischemic stroke (PAIS). Variable incidences and risk factors for long-term epilepsy in PAIS have been reported. To determine the incidence of epilepsy in PAIS survivors and report factors associated with the risk of developing epilepsy, a meta-analysis and systematic review of prior publications was performed.

METHODS

We examined studies on perinatal or neonatal patients (≤28 days of life) with arterial ischemic strokes in which the development of epilepsy was reported. EMBASE and MEDLINE/PubMed databases were systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

A meta-analysis of 10 studies revealed a summary incidence of epilepsy in PAIS patients of 27.2% (95% confidence interval 16.6% to 41.4%) over a mean study duration of 10.4 years (range 1.5 to 17). More recent studies generally reported a lower epilepsy incidence. A systematic review identified seven possible risk factors for epilepsy in PAIS patients: hippocampal volume reduction, infarct on prenatal ultrasound, a modified Alberta Stroke Program Early Computed Tomography score ≥9, family history of seizures, cerebral palsy, and initial presentation with cognitive impairment or seizures.

CONCLUSIONS

About a third of children with PAIS will develop epilepsy. While seven possible risk factors have been reported, further research is warranted to confirm the strength of their association with the development of epilepsy.

North American survey on the post-neuroimaging management of children with mild head injuries

OBJECTIVEThere remains uncertainty regarding the appropriate level of care and need for repeating neuroimaging among children with mild traumatic brain injury (mTBI) complicated by intracranial injury (ICI). This study's objective was to investigate physician practice patterns and decision-making processes for these patients in order to identify knowledge gaps and highlight avenues for future investigation.METHODSThe authors surveyed residents, fellows, and attending physicians from the following pediatric specialties: emergency medicine; general surgery; neurosurgery; and critical care. Participants came from 10 institutions in the United States and an email list maintained by the Canadian Neurosurgical Society. The survey asked respondents to indicate management preferences for and experiences with children with mTBI complicated by ICI, focusing on an exemplar clinical vignette of a 7-year-old girl with a Glasgow Coma Scale score of 15 and a 5-mm subdural hematoma without midline shift after a fall down stairs.RESULTSThe response rate was 52% (n = 536). Overall, 326 (61%) respondents indicated they would recommend ICU admission for the child in the vignette. However, only 62 (12%) agreed/strongly agreed that this child was at high risk of neurological decline. Half of respondents (45%; n = 243) indicated they would order a planned follow-up CT (29%; n = 155) or MRI scan (19%; n = 102), though only 64 (12%) agreed/strongly agreed that repeat neuroimaging would influence their management. Common factors that increased the likelihood of ICU admission included presence of a focal neurological deficit (95%; n = 508 endorsed), midline shift (90%; n = 480) or an epidural hematoma (88%; n = 471). However, 42% (n = 225) indicated they would admit all children with mTBI and ICI to the ICU. Notably, 27% (n = 143) of respondents indicated they had seen one or more children with mTBI and intracranial hemorrhage demonstrate a rapid neurological decline when admitted to a general ward in the last year, and 13% (n = 71) had witnessed this outcome at least twice in the past year.CONCLUSIONSMany physicians endorse ICU admission and repeat neuroimaging for pediatric mTBI with ICI, despite uncertainty regarding the clinical utility of those decisions. These results, combined with evidence that existing practice may provide insufficient monitoring to some high-risk children, emphasize the need for validated decision tools to aid the management of these patients.

The cost of hydrocephalus: a cost-effectiveness model for evaluating surgical techniques

In BriefThe authors analyzed the costs associated with the three different procedures used to treat hydrocephalus in the pediatric population. They believe this study highlights the importance of patient-specific treatment decisions that are based on etiology and previous intervention. The patient-specific medical characteristics are a driving force in the cost of care.

Oral presentation to publication: publication rates of abstract presentations across two pediatric neurosurgical meetings

OBJECTIVE Both the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Section on Pediatric Neurological Surgery (AANS/CNS Pediatric Section) and the International Society for Pediatric Neurosurgery (ISPN) annual meetings provide a platform for pediatric neurosurgeons to present, discuss, and disseminate current academic research. An ultimate goal of these meetings is to publish presented results in peer-reviewed journals. The purpose of the present study was to investigate the publication rates of oral presentations from the 2009, 2010, and 2011 AANS/CNS Pediatric Section and ISPN annual meetings in peer-reviewed journals. METHODS All oral presentations from the 2009, 2010, and 2011 AANS/CNS Pediatric Section and ISPN annual meetings were reviewed. Abstracts were obtained from the AANS/CNS Pediatric Section and ISPN conference proceedings, which are available online. Author and title information were used to search PubMed to identify those abstracts that had progressed to publication in peer-reviewed journals. The title of the journal, year of the publication, and authors' country of origin were also recorded. RESULTS Overall, 60.6% of the presented oral abstracts from the AANS/CNS Pediatric Section meetings progressed to publication in peer-reviewed journals, as compared with 40.6% of the ISPN presented abstracts (p = 0.0001). The journals in which the AANS/CNS Pediatric Section abstract-based publications most commonly appeared were Journal of Neurosurgery: Pediatrics (52%), Child's Nervous System (11%), and Journal of Neurosurgery (8%). The ISPN abstracts most often appeared in the journals Child's Nervous System (29%), Journal of Neurosurgery: Pediatrics (14%), and Neurosurgery (9%). Overall, more than 90% of the abstract-based articles were published within 4 years after presentation of the abstracts on which they were based. CONCLUSIONS Oral abstract presentations at two annual pediatric neurosurgery meetings have publication rates in peer-reviewed journal comparable to those for oral abstracts at other national and international neurosurgery meetings. The vast majority of abstract-based papers are published within 4 years of the meeting at which the abstract was presented; however, the AANS/CNS Pediatric Section abstracts are published at a significantly higher rate than ISPN abstracts, which could indicate the different meeting sizes, research goals, and resources of US authors compared with those of authors from other countries.

Comparison of hydrocephalus metrics between infants successfully treated with endoscopic third ventriculostomy with choroid plexus cauterization and those treated with a ventriculoperitoneal shunt: a multicenter matched-cohort analysis

OBJECTIVE It has been suggested that the treatment of infant hydrocephalus results in different craniometric changes depending upon whether ventriculoperitoneal shunt (VPS) placement or endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) is performed. Without an objective and quantitative description of expected changes to the infant cranium and ventricles following ETV/CPC, asserting successful treatment of hydrocephalus is difficult. By comparing infants successfully treated via ETV/CPC or VPS surgery, the authors of this study aimed to define the expected postoperative cranial and ventricular alterations at the time of clinical follow-up. METHODS Patients who underwent successful treatment of hydrocephalus at 4 institutions with either VPS placement or ETV/CPC were matched in a 3:1 ratio on the basis of age and etiology. Commonly used cranial parameters (including head circumference [HC], HC z-score, fontanelle status, and frontooccipital horn ratio [FOHR]) were compared pre- and postoperatively between treatment cohorts. First, baseline preoperative values were compared to ensure cohort equivalence. Next, postoperative metrics, including the relative change in metrics, were compared between treatment groups using multivariate linear regression. RESULTS Across 4 institutions, 18 ETV/CPC-treated and 54 VPS-treated infants with hydrocephalus were matched and compared at 6 months postoperatively. The most common etiologies of hydrocephalus were myelomeningocele (61%), followed by congenital communicating hydrocephalus (17%), aqueductal stenosis (11%), and intraventricular hemorrhage (6%). The mean age at the time of CSF diversion was similar between ETV/CPC- and VPS-treated patients (3.4 vs 2.9 months; p = 0.69), as were all preoperative cranial hydrocephalus metrics (p > 0.05). Postoperatively, the ventricle size FOHR decreased significantly more following VPS surgery (-0.15) than following ETV/CPC (-0.02) (p < 0.001), yielding a lower postoperative FOHR in the VPS arm (0.42 vs 0.51; p = 0.01). The HC percentile was greater in the ETV/CPC cohort than in the VPS-treated patients (76th vs 54th percentile; p = 0.046). A significant difference in the postoperative z-score was not observed. With both treatment modalities, a bulging fontanelle reliably normalized at last follow-up. CONCLUSIONS Clinical and radiographic parameters following successful treatment of hydrocephalus in infants differed between ETV/CPC and VPS treatment. At 6 months post-ETV/CPC, ventricle size remained unchanged, whereas VPS-treated ventricles decreased to a near-normal FOHR. The HC growth control between the procedures was similar, although the final HC percentile may be lower after VPS. The fontanelle remained a reliable indicator of success for both treatments. This study establishes expected cranial and ventricular parameters following ETV/CPC, which may be used to guide preoperative counseling and postoperative decision making.

Management of Penetrating Cerebrovascular Injuries in Pediatric Trauma: A Retrospective Multicenter Study

BACKGROUND

Blunt cerebrovascular injury is uncommon in the pediatric population; penetrating cerebrovascular injuries are even rarer and are thus poorly understood.

OBJECTIVE

To describe the diagnosis and management of penetrating cerebrovascular injuries and describe outcomes of available treatment modalities.

METHODS

Clinical and radiographic data were collected retrospectively from a multicenter trauma registry for children screened for cerebrovascular injury during 2003 to 2013 at 4 academic pediatric trauma centers.

RESULTS

Among 645 pediatric patients evaluated with computed tomography angiography with blunt cerebrovascular injury, 130 also had a penetrating trauma indication. Seven penetrating cerebrovascular injuries were diagnosed in 7 male patients (mean age 12.4 years, range 12-18 years). Focal neurological deficit and concomitant intracranial injury were each seen in 2 patients. There were 2 intracranial carotid artery injuries, 4 extracranial carotid artery injuries, and 1 vertebral artery injury. The majority of injuries were higher than grade I (5/7; 71%): 2 were grade I, 1 grade II, 2 grade III, and 2 grade IV. The 2 patients with grade III injuries required open surgery, and 1 patient with a grade IV injury underwent endovascular treatment. Two patients suffered immediate stroke secondary to the penetrating cerebrovascular injury. There were no delayed neurological deficits from the penetrating injuries, and no patients died as a result of the injuries.

CONCLUSION

This is the largest series of penetrating cerebrovascular trauma in the pediatric literature. Although rare, penetrating cerebrovascular injuries can be high-grade injuries that require urgent recognition and may require aggressive endovascular and/or open surgery for treatment.

Endoscopic third ventriculostomy and choroid plexus cauterization in infant hydrocephalus: a prospective study by the Hydrocephalus Clinical Research Network

OBJECTIVE High-quality data comparing endoscopic third ventriculostomy (ETV) with choroid plexus cauterization (CPC) to shunt and ETV alone in North America are greatly lacking. To address this, the Hydrocephalus Clinical Research Network (HCRN) conducted a prospective study of ETV+CPC in infants. Here, these prospective data are presented and compared to prospectively collected data from a historical cohort of infants treated with shunt or ETV alone. METHODS From June 2014 to September 2015, infants (corrected age ≤ 24 months) requiring treatment for hydrocephalus with anatomy suitable for ETV+CPC were entered into a prospective study at 9 HCRN centers. The rate of procedural failure (i.e., the need for repeat hydrocephalus surgery, hydrocephalus-related death, or major postoperative neurological deficit) was determined. These data were compared with a cohort of similar infants who were treated with either a shunt (n = 969) or ETV alone (n = 74) by creating matched pairs on the basis of age and etiology. These data were obtained from the existing prospective HCRN Core Data Project. All patients were observed for at least 6 months. RESULTS A total of 118 infants underwent ETV+CPC (median corrected age 1.3 months; common etiologies including myelomeningocele [30.5%], intraventricular hemorrhage of prematurity [22.9%], and aqueductal stenosis [21.2%]). The 6-month success rate was 36%. The most common complications included seizures (5.1%) and CSF leak (3.4%). Important predictors of treatment success in the survival regression model included older age (p = 0.002), smaller preoperative ventricle size (p = 0.009), and greater degree of CPC (p = 0.02). The matching algorithm resulted in 112 matched pairs for ETV+CPC versus shunt alone and 34 matched pairs for ETV+CPC versus ETV alone. ETV+CPC was found to have significantly higher failure rate than shunt placement (p < 0.001). Although ETV+CPC had a similar failure rate compared with ETV alone (p = 0.73), the matched pairs included mostly infants with aqueductal stenosis and miscellaneous other etiologies but very few patients with intraventricular hemorrhage of prematurity. CONCLUSIONS Within a large and broad cohort of North American infants, our data show that overall ETV+CPC appears to have a higher failure rate than shunt alone. Although the ETV+CPC results were similar to ETV alone, this comparison was limited by the small sample size and skewed etiological distribution. Within the ETV+CPC group, greater extent of CPC was associated with treatment success, thereby suggesting that there are subgroups who might benefit from the addition of CPC. Further work will focus on identifying these subgroups.

Unplanned readmission within 90 days after pediatric neurosurgery

OBJECTIVE Readmission and return to operating room after surgery are increasingly being used as a proxy for quality of care. Nearly 60% of these readmissions are unplanned, which translates into billions of dollars in health care costs. The authors set out to analyze the incidence of readmission at their center, to define causes of unplanned readmission, and to determine the preoperative and surgical variables associated with readmissions following pediatric neurosurgery. METHODS A total of 536 children who underwent operations for neurosurgical diagnoses between 2012 and 2015 and who were later readmitted were included in the final analysis. Unplanned readmissions were defined to have occurred as a result of complications within 90 days after index surgery. Patient records were retrospectively reviewed to determine the primary diagnosis, surgery indication, and cause of readmission and return to operating room. The cost for index hospitalization, readmission episode, and total cost were derived based on the charges obtained from administrative data. Bivariate and multivariable analyses were conducted. RESULTS Of 536 patients readmitted in total, 17.9% (n = 96) were readmitted within 90 days. Of the overall readmissions, 11.9% (n = 64) were readmitted within 30 days, and 5.97% (n = 32) were readmitted between 31 and 90 days. The median duration between discharge and readmission was 20 days (first quartile [Q1]: 9 days, third quartile [Q3]: 36 days). The most common reason for readmission was shunt related (8.2%, n = 44), followed by wound infection (4.7%, n = 25). In the risk-adjusted multivariable logistic regression model for total 90-day readmission, patients with the following characteristics: younger age (p = 0.001, OR 0.886, 95% CI 0.824-0.952); "other" (nonwhite, nonblack) race (p = 0.024, OR 5.49, 95% CI 1.246-24.2); and those born preterm (p = 0.032, OR 2.1, 95% CI 1.1-4.12) had higher odds of being readmitted within 90 days after discharge. The total median cost for patients undergoing surgery in this study cohort was $11,520 (Q1: $7103, Q3: $19,264). For the patients who were readmitted, the median cost for a readmission episode was $8981 (Q1: $5051, Q3: $18,713). CONCLUSIONS Unplanned 90-day readmissions in pediatric neurosurgery are primarily due to CSF-related complications. Patients with the following characteristics: young age at presentation; "other" race; and children born preterm have a higher likelihood of being readmitted within 90 days after surgery. The median cost was > $8000, which suggests that the readmission episode can be as expensive as the index hospitalization. Clearly, readmission reduction has the potential for significant cost savings in pediatric neurosurgery. Future efforts, such as targeted education related to complication signs, should be considered in the attempt to reduce unplanned events. Given the single-center, retrospective study design, the results of this study are primarily applicable to this population and cannot necessarily be generalized to other institutions without further study.

Treatment Practices and Outcomes After Blunt Cerebrovascular Injury in Children

BACKGROUND

Pediatric blunt cerebrovascular injury (BCVI) lacks accepted treatment algorithms, and postinjury outcomes are ill defined.

OBJECTIVE

To compare treatment practices among pediatric trauma centers and to describe outcomes for available treatment modalities.

METHODS

Clinical and radiographic data were collected from a patient cohort with BCVI between 2003 and 2013 at 4 academic pediatric trauma centers.

RESULTS

Among 645 pediatric patients evaluated with computed tomography angiography for BCVI, 57 vascular injuries (82% carotid artery, 18% vertebral artery) were diagnosed in 52 patients. Grade I (58%) and II (23%) injuries accounted for most lesions. Severe intracranial or intra-abdominal hemorrhage precluded antithrombotic therapy in 10 patients. Among the remaining patients, primary therapy was an antiplatelet agent in 14 (33%), anticoagulation in 8 (19%), endovascular intervention in 3 (7%), open surgery in 1 (2%), and no treatment in 16 (38%). Among 27 eligible grade I injuries, 16 (59%) were not treated, and the choice to not treat varied significantly among centers (P < .001). There were no complications from medical management. Glasgow Coma Scale (GCS) score <8 and increasing injury grade were predictors of injury progression (P = .001 and .004, respectively). Poor GCS score (P = .02), increasing injury grade (P = .03), and concomitant intracranial injury (P = .02) correlated with increased risk of mortality. Treatment modality did not correlate with progression of vascular injury or mortality.

CONCLUSION

Treatment of BCVI with antiplatelet or anticoagulant therapy is safe and may confer modest benefit. Nonmodifiable factors, including presenting GCS score, vascular injury grade, and additional intracranial injury, remain the most important predictors of poor outcome.

ABBREVIATIONS

ATT, antithrombotic therapyBCVI, blunt cerebrovascular injuryCTA, computed tomography angiographyGCS, Glasgow Coma Scale.

X-ray vs. CT in identifying significant C-spine injuries in the pediatric population

PURPOSE

Evaluation of cervical spine injury (CSI) in children requires rapid, yet accurate assessment of damage. Given concerns of radiation exposure, expert consensus advises that computed tomography (CT) should be used sparingly. However, CT can provide superior image resolution and detection of pathology. Herein, we evaluate if X-ray offers equal diagnostic accuracy compared to CT imaging in identifying CSI in children.

METHODS

We conducted a retrospective study between October 2000 and March 2012 of pediatric patients evaluated for cervical spine injury at a level 1 trauma center. All patients included in this study were imaged with cervical spine X-rays and CT at the time of injury. Demographic information, mechanism of injury, significant versus non-significant injury (as defined by the NEXUS criteria), radiographic findings, level of the injury, presence of spinal cord injury, treatment, clinical outcome, and length of follow-up were collected. Chi-squared (χ ²) and Fisher's exact tests were used as appropriate and means and standard deviations were reported.

RESULTS

We identified 1296 patients who were screened for CSI. Of those, 164 patients were diagnosed with spinal cord/column injuries (CSI). Eighty-nine patients were excluded for only having a CT or X-ray imaging without the other modality. Thus, a total of 75 patients with CSI were included in the final cohort. Using the NEXUS definitions, 78% of patients had clinically significant injuries while 22% had non-significant injuries. There were no injuries detected on X-ray that were not also detected on CT. For all injuries, X-ray sensitivity was 50.7%. X-rays were more sensitive to significant injuries (62.3%) compared in non-significant injuries, which were missed on all X-rays (0%). Therefore, X-rays did not identify 24 significant cervical spine injuries (32%) as defined by NEXUS.

CONCLUSIONS

CT is superior to X-rays in detecting both clinically significant and insignificant cervical spine injuries. These results were not dependent on patient age or location of the injury. We recommend CT imaging in the evaluation of suspected cervical spine injuries in children.

LEVEL OF EVIDENCE

III.