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Michael C. Dewan, Jaims Lim, Chevis N. Shannon and John C. Wellons III

OBJECTIVE

Up to one-third of patients with a posterior fossa brain tumor (PFBT) will experience persistent hydrocephalus mandating permanent CSF diversion. The optimal hydrocephalus treatment modality is unknown; the authors sought to compare the durability between endoscopic third ventriculostomy (ETV) and ventriculoperitoneal shunt (VPS) therapy in the pediatric population.

METHODS

The authors conducted a systematic review of articles indexed in PubMed between 1986 and 2016 describing ETV and/or VPS treatment success/failure and time-to-failure rate in patients < 19 years of age with hydrocephalus related to a PFBT. Additionally, the authors conducted a retrospective review of their institutional series of PFBT patients requiring CSF diversion. Patient data from the systematic review and from the institutional series were aggregated and a time-to-failure analysis was performed comparing ETV and VPS using the Kaplan-Meier method.

RESULTS

A total of 408 patients were included from 12 studies and the authors' institutional series: 284 who underwent ETV and 124 who underwent VPS placement. The analysis included uncontrolled studies with variable method and timing of CSF diversion and were subject to surgeon bias. No significant differences between cohorts were observed with regard to age, sex, tumor grade or histology, metastatic status, or extent of resection. The cumulative failure rate of ETV was 21%, whereas that of VPS surgery was 29% (p = 0.105). The median time to failure was earlier for ETV than for VPS surgery (0.82 [IQR 0.2–1.8] vs 4.7 months [IQR 0.3–5.7], p = 0.03). Initially the ETV survival curve dropped sharply and then stabilized around 2 months. The VPS curve fell gradually but eventually crossed below the ETV curve at 5.7 months. Overall, a significant survival advantage was not demonstrated for one procedure over the other (p = 0.21, log-rank). However, postoperative complications were higher following VPS (31%) than ETV (17%) (p = 0.012).

CONCLUSIONS

ETV failure occurred sooner than VPS failure, but long-term treatment durability may be higher for ETV. Complications occurred more commonly with VPS than with ETV. Limited clinical conclusions are drawn using this methodology; the optimal treatment for PFBT-related hydrocephalus warrants investigation through prospective studies.

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Jonathan Dallas, Chevis N. Shannon and Christopher M. Bonfield

OBJECTIVE

Spinal fusion is used in the treatment of pediatric neuromuscular scoliosis (NMS) to improve spine alignment and delay disease progression. However, patients with NMS are often medically complex and require a higher level of care than those with other types of scoliosis, leading to higher treatment costs. The purpose of this study was to 1) characterize the cost of pediatric NMS fusion in the US and 2) determine hospital characteristics associated with changes in overall cost.

METHODS

Patients were identified from the National Inpatient Sample (2012 to the first 3 quarters of 2015). Inclusion criteria selected for patients with NMS, spinal fusion of at least 4 vertebral levels, and elective hospitalization. Patients with no cost information were excluded. Sociodemographics, treating hospital characteristics, disease etiology/severity, comorbidities, length of stay, and hospital costs were collected. Univariable analysis and multivariable gamma log-link regression were used to determine hospital characteristics associated with changes in cost.

RESULTS

A total of 1780 weighted patients met inclusion criteria. The median cost was $68,815. Following multivariable regression, both small (+$11,580, p < 0.001) and medium (+$6329, p < 0.001) hospitals had higher costs than large hospitals. Rural hospitals had higher costs than urban teaching hospitals (+$32,438, p < 0.001). Nonprofit hospitals were more expensive than both government (–$4518, p = 0.030) and investor-owned (–$10,240, p = 0.001) hospitals. There was significant variability by US census division; compared with the South Atlantic, all other divisions except for the Middle Atlantic had significantly higher costs, most notably the West North Central (+$15,203, p < 0.001) and the Pacific (+$22,235, p < 0.001). Hospital fusion volume was not associated with total cost.

CONCLUSIONS

A number of hospital factors were associated with changes in fusion cost. Larger hospitals may be able to achieve decreased costs due to economies of scale. Regional differences could reflect uncontrolled-for variability in underlying patient populations or systems-level and policy differences. Overall, this analysis identified multiple systemic patterns that could be targets of further cost-related interventions.

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Travis R. Ladner, Ashly C. Westrick, John C. Wellons III and Chevis N. Shannon

OBJECT

The purpose of this study was to design and validate a patient-reported health-related quality of life (HRQOL) instrument for pediatric Chiari Type I malformation (CM-I), the Chiari Health Index for Pediatrics (CHIP).

METHODS

The CHIP has 45 items with 4 components making up 2 domain scores, physical (pain frequency, pain severity, nonpain symptoms) and psychosocial; physical and psychosocial scores are combined to create an overall HRQOL score. Increasing scores (0 to 1) represent increasing HRQOL. Fifty-five patients with CM-I (mean age 12 ± 4 years, 53% male) were enrolled and completed the CHIP and Health Utilities Index Mark 3 (HUI3). Twenty-five healthy controls (mean age 11.9 ± 4 years, 40% male) also completed the CHIP. CHIP scores were compared between these groups via the Mann-Whitney U-test. For CHIP discriminative function, subscore versus presence of CM-I was compared via receiver operating characteristic curve analysis. CHIP scores in the CM-I group were stratified by symptomatology (asymptomatic, headaches, and paresthesias) and compared via Kruskal-Wallis test with Mann-Whitney U-test with Bonferroni correction (p < 0.0167). CHIP was compared with HUI3 (Health Utilities Index Mark 3) via univariate and multivariate linear regression.

RESULTS

CHIP physical and psychosocial subscores were, respectively, 24% and 18% lower in CM-I patients than in controls (p < 0.001); the overall HRQOL score was 23% lower as well (p < 0.001). The area under the curve (AUC) for CHIP physical subscore versus presence of CM-I was 0.809. CHIP physical subscore varied significantly with symptomatology (p = 0.001) and HUI3 pain-related quality of life (R2 = 0.311, p < 0.001). The AUC for CHIP psychosocial subscore versus presence of CM-I was 0.754. CHIP psychosocial subscore varied significantly with HUI3 cognitive- (R2 = 0.324, p < 0.001) and emotion-related (R2 = 0.155, p = 0.003) quality of life. The AUC for CHIP HRQOL versus presence of CM-I was 0.820. Overall CHIP HRQOL score varied significantly with symptomatology (p = 0.001) and HUI3 multiattribute composite HRQOL score (R2 = 0.440, p < 0.001).

CONCLUSIONS

The CHIP is a patient-reported, CM-I-specific HRQOL instrument, with construct validity in assessing pain-, cognitive-, and emotion-related quality of life, as well as symptomatic features unique to CM-I. It holds promise as a discriminative HRQOL index in CM-I outcomes assessment.

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Christopher M. Bonfield, Rachel Pellegrino, Jillian Berkman, Robert P. Naftel, Chevis N. Shannon and John C. Wellons III

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.

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Emily W. Chan, Stephen R. Gannon, Chevis N. Shannon, Jeffrey E. Martus, Gregory A. Mencio and Christopher M. Bonfield

OBJECTIVE

Adolescent idiopathic scoliosis (AIS), the most common type of scoliosis, often presents immediately prior to a woman’s childbearing years; however, research investigating the impact of AIS on women’s health, particularly pregnancy delivery outcomes, is sparse, with existing literature reporting mixed findings. Similarly limited are studies examining the change in scoliotic curve during or after pregnancy. Therefore, this study aims to determine 1) the impact of scoliotic curvature on obstetric complications (preterm births, induction of labor, and urgent/emergency caesarean section delivery), 2) regional anesthetic decision making and success during delivery for these patients, and 3) the effect of pregnancy on curve progression.

METHODS

Records of all pregnant patients diagnosed with AIS at the authors’ institution who delivered between January 2002 and September 2016 were retrospectively reviewed. Demographic information, pre- and postpartum radiographic Cobb angles, and clinical data for each pregnancy and delivery were recorded and analyzed. The Wilcoxon rank-sum test and the Wilcoxon signed-rank test were used for statistical analyses.

RESULTS

Fifty-nine patients (84 deliveries) were included; 14 patients had undergone prior posterior spinal fusion. The median age at AIS diagnosis was 15.2 years, and the median age at delivery was 21.8 years. Overall, the median major Cobb angle prior to the first pregnancy was 25° (IQR 15°–40°). Most births were by spontaneous vaginal delivery (n = 45; 54%); elective caesarean section was performed in 17 deliveries (20%). Obstetric complications included preterm birth (n = 18; 21.4%), induction of labor (n = 20; 23.8%), and urgent/emergency caesarean section (n = 12; 14.0%); none were associated with severity of scoliosis curve or prior spinal fusion. Attempts at spinal anesthesia were successful 99% of the time (70/71 deliveries), even among the patients who had undergone prior spinal fusion (n = 13). There were only 3 instances of provider refusal to administer spinal anesthesia. In the subset of 11 patients who underwent postpartum scoliosis radiography, there was no statistically significant change in curve magnitude either during or immediately after pregnancy.

CONCLUSIONS

The results of this study suggest that there was no effect of the severity of scoliosis on delivery complications or regional anesthetic decision making in pregnant patients with AIS. Moreover, scoliosis was not observed to progress significantly during or immediately after pregnancy. Larger prospective studies are needed to further investigate these outcomes, the findings of which can guide the prenatal education and counseling of pregnant patients with AIS.

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Ranbir Ahluwalia, Chelsea Kiely, Jarrett Foster, Stephen Gannon, Alyssa L. Wiseman, Chevis N. Shannon and Christopher M. Bonfield

OBJECTIVE

The authors sought to assess the prevalence and severity of positional posterior plagiocephaly (PPP) in the pediatric population at a tertiary care center.

METHODS

The authors conducted a retrospective review of 1429 consecutive patients aged 2 months to 18 years who presented with head trauma and a negative CT scan in 2018. The cohort was stratified by age. The cranial vault asymmetry index (CVAI) was calculated at the superior orbital rim. Asymmetry was categorized according to the following CVAI scores: mild (3.5%–7%), moderate (7%–12%), and severe (> 12%). Patients were grouped by age to assess PPP at different stages of head development: group 1, 2–5 months; group 2, 6–11 months; group 3, 12–23 months; group 4: 2–4 years; group 5, 5–8 years; group 6, 9–12 years; and group 7, 13–18 years. Patients with a history of shunted hydrocephalus, craniosynostosis, skull surgery, or radiographic evidence of intracranial trauma were excluded.

RESULTS

The overall cohort prevalence of PPP was 24.8% (354 patients). PPP prevalence was higher among younger patients from groups 1–3 (40.4%, 33.5%, and 0.8%, respectively). There was a continued decline in PPP by age in groups 4–7 (26.4%, 20%, 20%, and 10.8%, respectively). Mild cranial vault asymmetry was noted most often (78.0%, 276 patients), followed by moderate (19.5%, 69 patients) and severe (2.5%, 9 patients). There were no patients in group 6 or 7 with severe PPP.

CONCLUSIONS

PPP is prevalent in pediatric populations and most commonly presents as a case of mild asymmetry. Although there was an overall decline of PPP prevalence with increasing age, moderate asymmetry was seen in all age groups. No patients in the cohort had severe asymmetry that persisted into adolescence.

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Andrew T. Hale, David P. Stonko, Amber Brown, Jaims Lim, David J. Voce, Stephen R. Gannon, Truc M. Le and Chevis N. Shannon

OBJECTIVE

Modern surgical planning and prognostication requires the most accurate outcomes data to practice evidence-based medicine. For clinicians treating children following traumatic brain injury (TBI) these data are severely lacking. The first aim of this study was to assess published CT classification systems in the authors’ pediatric cohort. A pediatric-specific machine-learning algorithm called an artificial neural network (ANN) was then created that robustly outperformed traditional CT classification systems in predicting TBI outcomes in children.

METHODS

The clinical records of children under the age of 18 who suffered a TBI and underwent head CT within 24 hours after TBI (n = 565) were retrospectively reviewed.

RESULTS

“Favorable” outcome (alive with Glasgow Outcome Scale [GOS] score ≥ 4 at 6 months postinjury, n = 533) and “unfavorable” outcome (death at 6 months or GOS score ≤ 3 at 6 months postinjury, n = 32) were used as the primary outcomes. The area under the receiver operating characteristic (ROC) curve (AUC) was used to delineate the strength of each CT grading system in predicting survival (Helsinki, 0.814; Rotterdam, 0.838; and Marshall, 0.781). The AUC for CT score in predicting GOS score ≤ 3, a measure of overall functionality, was similarly predictive (Helsinki, 0.717; Rotterdam, 0.748; and Marshall, 0.663). An ANN was then constructed that was able to predict 6-month outcomes with profound accuracy (AUC = 0.9462 ± 0.0422).

CONCLUSIONS

This study showed that machine-learning can be leveraged to more accurately predict TBI outcomes in children.

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Jonathan Dallas, Evan Mercer, Rebecca A. Reynolds, John C. Wellons III, Chevis N. Shannon and Christopher M. Bonfield

OBJECTIVE

Isolated, nondisplaced skull fractures (ISFs) are a common result of pediatric head trauma. They rarely require surgical intervention; however, many patients with these injuries are still admitted to the hospital for observation. This retrospective study investigates predictors of vomiting and ondansetron use following pediatric ISFs and the role that these factors play in the need for admission and emergency department (ED) revisits.

METHODS

The authors identified pediatric patients (< 18 years old) with a linear ISF who had presented to the ED of a single tertiary care center between 2008 and 2018. Patients with intracranial hemorrhage, significant fracture displacement, or other traumatic injuries were excluded. Outcomes included vomiting, ondansetron use, admission, and revisit following ED discharge. Both univariable and multivariable analyses were used to determine significant predictors of each outcome (p < 0.05).

RESULTS

Overall, 518 patients were included in this study. The median patient age was 9.98 months, and a majority of the patients (59%) were male. The most common fracture locations were parietal (n = 293 [57%]) and occipital (n = 144 [28%]). Among the entire patient cohort, 124 patients (24%) had documented vomiting, and 64 of these patients (52%) received ondansetron. In a multivariable analysis, one of the most significant predictors of vomiting was occipital fracture location (OR 4.05, p < 0.001). In turn, and as expected, both vomiting (OR 14.42, p < 0.001) and occipital fracture location (OR 2.66, p = 0.017) were associated with increased rates of ondansetron use. A total of 229 patients (44%) were admitted to the hospital, with vomiting as the most common indication for admission (n = 59 [26%]). Moreover, 4.1% of the patients had ED revisits following initial discharge, and the most common reason was vomiting (11/21 [52%]). However, in the multivariable analysis, ondansetron use at initial presentation (and not vomiting) was the sole predictor of revisit following initial ED discharge (OR 5.05, p = 0.009).

CONCLUSIONS

In this study, older patients and those with occipital fractures were more likely to present with vomiting and to be treated with ondansetron. Additionally, ondansetron use at initial presentation was found to be a significant predictor of revisits following ED discharge. Ondansetron could be masking recurrent vomiting in ED patients, and this should be considered when deciding which patients to observe further or discharge.

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Travis R. Ladner, Michael C. Dewan, Matthew A. Day, Chevis N. Shannon, Luke Tomycz, Noel Tulipan and John C. Wellons III

OBJECT

Osseous anomalies of the craniocervical junction are hypothesized to precipitate the hindbrain herniation observed in Chiari I malformation (CM-I). Previous work by Tubbs et al. showed that posterior angulation of the odontoid process is more prevalent in children with CM-I than in healthy controls. The present study is an external validation of that report. The goals of our study were 3-fold: 1) to externally validate the results of Tubbs et al. in a different patient population; 2) to compare how morphometric parameters vary with age, sex, and symptomatology; and 3) to develop a correlative model for tonsillar ectopia in CM-I based on these measurements.

METHODS

The authors performed a retrospective review of 119 patients who underwent posterior fossa decompression with duraplasty at the Monroe Carell Jr. Children’s Hospital at Vanderbilt University; 78 of these patients had imaging available for review. Demographic and clinical variables were collected. A neuroradiologist retrospectively evaluated preoperative MRI examinations in these 78 patients and recorded the following measurements: McRae line length; obex displacement length; odontoid process parameters (height, angle of retroflexion, and angle of retroversion); perpendicular distance to the basion-C2 line (pB–C2 line); length of cerebellar tonsillar ectopia; caudal extent of the cerebellar tonsils; and presence, location, and size of syringomyelia. Odontoid retroflexion grade was classified as Grade 0, > 90°; Grade I,85°–89°; Grade II, 80°–84°; and Grade III, < 80°. Age groups were defined as 0–6 years, 7–12 years, and 13–17 years at the time of surgery. Univariate and multivariate linear regression analyses, Kruskal-Wallis 1-way ANOVA, and Fisher’s exact test were performed to assess the relationship between age, sex, and symptomatology with these craniometric variables.

RESULTS

The prevalence of posterior odontoid angulation was 81%, which is almost identical to that in the previous report (84%). With increasing age, the odontoid height (p < 0.001) and pB–C2 length (p < 0.001) increased, while the odontoid process became more posteriorly inclined (p = 0.010). The pB–C2 line was significantly longer in girls (p = 0.006). These measurements did not significantly correlate with symptomatology. Length of tonsillar ectopia in pediatric CM-I correlated with an enlarged foramen magnum (p = 0.023), increasing obex displacement (p = 0.020), and increasing odontoid retroflexion (p < 0.001).

CONCLUSIONS

Anomalous bony development of the craniocervical junction is a consistent feature of CM-I in children. The authors found that the population at their center was characterized by posterior angulation of the odontoid process in 81% of cases, similar to findings by Tubbs et al. (84%). The odontoid process appeared to lengthen and become more posteriorly inclined with age. Increased tonsillar ectopia was associated with more posterior odontoid angulation, a widened foramen magnum, and an inferiorly displaced obex.

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Michael C. Dewan, Jaims Lim, Clinton D. Morgan, Stephen R. Gannon, Chevis N. Shannon, John C. Wellons III and Robert P. Naftel

OBJECTIVE

Endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) offers an alternative to shunt treatment for infantile hydrocephalus. Diagnosing treatment failure is dependent on infantile hydrocephalus metrics, including head circumference, fontanel quality, and ventricle size. However, it is not clear to what degree these metrics should be expected to change after ETV/CPC. Using these clinical metrics, the authors present and analyze the decision making in cases of ETV/CPC failure.

METHODS

Infantile hydrocephalus metrics, including bulging fontanel, head circumference z-score, and frontal and occipital horn ratio (FOHR), were compared between ETV/CPC failures and successes. Treatment outcome predictive values of metrics individually and in combination were calculated.

RESULTS

Forty-four patients (57% males, median age 1.2 months) underwent ETV/CPC for hydrocephalus; of these patients, 25 (57%) experienced failure at a median time of 51 days postoperatively. Patients experiencing failure were younger than those experiencing successful treatment (0.8 vs 3.9 months, p = 0.01). During outpatient follow-up, bulging anterior fontanel, progressive macrocephaly, and enlarging ventricles each demonstrated a positive predictive value (PPV) of no less than 71%, but a bulging anterior fontanel remained the most predictive indicator of ETV/CPC failure, with a PPV of 100%, negative predictive value of 73%, and sensitivity of 72%. The highest PPVs and specificities existed when the clinical metrics were present in combination, although sensitivities decreased expectedly. Only 48% of failures were diagnosed on the basis all 3 hydrocephalus metrics, while only 37% of successes were negative for all 3 metrics. In the remaining 57% of patients, a diagnosis of success or failure was made in the presence of discordant data.

CONCLUSIONS

Successful ETV/CPC for infantile hydrocephalus was evaluated in relation to fontanel status, head growth, and change in ventricular size. In most patients, a designation of failure or success was made in the setting of discordant data.