A systematic review of the power of standardization in pediatric neurosurgery.

In the current neurosurgical field, there is a constant emphasis on providing the best care with the most value. Such work requires the constant optimization of not only surgical but also perioperative services. Recent work has demonstrated the power of standardized techniques in limiting complication while promoting optimal outcomes. In this review article, protocols addressing operative and perioperative care for common pediatric neurosurgical procedures are discussed. These articles address how various institutions have optimized procedures through standardization. Our objective is to improve patient outcomes through the optimization of protocols.

Arteriovenous malformation with unique drainage through the emissary vein of the foramen ovale: illustrative case.

BACKGROUND: As part of the laterotrigeminal venous system (LTVS), the emissary vein of the foramen ovale (EVFO) is an underrecognized venous structure communicating between the cavernous sinus and pterygoid plexus. The sphenobasal sinus is an anatomical variation of the sphenoparietal sinus that drains directly into the EVFO. The authors present the case of a ruptured arteriovenous malformation (AVM) with a unique drainage pattern through the sphenobasal sinus and EVFO. OBSERVATIONS: A 9-year-old female initially presented with loss of consciousness and was subsequently found to have a ruptured AVM in the left basal frontal area. She underwent an immediate decompressive hemicraniectomy, with a computed tomography angiogram demonstrating a unique anatomical variation in which the sphenobasal sinus communicated with the EVFO and LTVS. The final venous drainage returned to the pterygoid plexus and external jugular vein. Postoperatively, the patient made a substantial recovery, with generalized right-sided weakness remaining as the sole deficit. LESSONS: The authors present the case of a ruptured AVM with unique venous drainage into the sphenobasal sinus and EVFO, for which the current literature remains limited. As exemplified by this illustrative case, technique modification may be warranted in the setting of this unique anatomical variation to avoid venous sinus injury.

Ventriculoperitoneal shunt placement following endoscopic third ventriculostomy failure in the treatment of pediatric hydrocephalus.

OBJECTIVE: The goal of this study was to evaluate the impact of endoscopic third ventriculostomy (ETV) failure on subsequent risk of ventriculoperitoneal shunt (VPS) placement. METHODS: A retrospective chart review was performed to identify pediatric patients receiving ETV followed by a VPS at Oklahoma Children's Hospital between January 1, 2016, and December 31, 2021. A control group of patients receiving a VPS alone was also gathered. Complication and shunt failure rates were compared between the 2 groups at 12 months postoperatively. RESULTS: A total of 222 patients were included in this study. The VPS placement after ETV failure (VPSEF) group included 21 patients; 53% were male and 47% were female, with a mean age of 2.2 years and standard deviation of 4.3 years. The etiology of hydrocephalus was chiefly intraventricular hemorrhage (43%) and neural tube defects (19%). At 12 months after VPS placement, the complication rate was 24%, predominantly including infection (19%) or CSF leakage (10%). The VPS-only (VPSO) group included 201 patients; 51% were male and 49% were female, with a mean age of 4.2 years and standard deviation of 6.5 years. The etiology of hydrocephalus was chiefly intraventricular hemorrhage (26%) and neural tube defects (30%). At 12 months postoperatively, the complication rate was 10%, predominantly including infection (6%) or catheter-associated hemorrhage (3%). The difference in complication rates between the VPSEF and VPSO groups was not significant at 12 months postoperatively (p = 0.07); however, on subgroup analysis there was a significantly higher rate of CSF leakage at 12 months in the VPSEF group compared to the VPSO group (p = 0.0371). CONCLUSIONS: There was no difference in overall complication rates for the treatment of pediatric hydrocephalus by VPS following failed ETV compared to VPS placement alone, yet prior ETV may predispose patients to a higher rate of CSF leaks within 12 months of VPS placement. Further study is indicated to determine whether a prior ETV procedure predisposes patients to a higher complication rate on VPS placement.

Pediatric neurosurgery through the lens of time-driven activity-based costing: a pilot study.

OBJECTIVE: Time-driven activity-based costing (TDABC) is a method used in cost accounting that has gained traction in health economics to identify value optimization initiatives. It measures time, assigns value to time increments spent on a patient, and integrates the cost of material and human resources utilized in each episode of care. In this study, the authors report the first use of TDABC to evaluate costs in a pediatric neurosurgical practice. METHODS: A clinical pathway was developed with a multifunction team. A time survey among each care team member, including surgeons, medical assistants (MAs), and patient service representatives (PSRs), was carried out prospectively over a 10-week period at a pediatric neurosurgery clinic. Consecutive patient encounters for Chiari malformation (CM), hydrocephalus, or tethered cord syndrome (TCS) were included. Encounters were categorized as new or established. Relative annual personnel costs, using the salary of a PSR as a reference (i.e., 1.0-unit cost), were calculated for all members using departmental financial data after adjustments. The relative capacity cost rates (minute-1) for each personnel, a representation of per capita cost per minute, were then derived, and the relative costs per visit were calculated. RESULTS: A total of 110 visits (24 new, 86 established) were captured, including 40% CM, 41% hydrocephalus, and 19% TCS encounters. Surgeons had the highest relative capacity cost rate (118.4 × 10-6), more than 10-fold higher than that of an MA or PSR (10.65 × 10-6 and 9.259 × 10-6, respectively). Surgeons also logged more time with patients compared with the rest of the care team in nearly all visits (p ≤ 0.002); consequently, the total visit costs were primarily driven by the surgeon cost (p < 0.0001). Overall, surgeon cost constituted the vast majority of the total visit cost (92%-93%), regardless of whether the visits were new or established. Visit costs did not differ by diagnosis. On average, new visits took longer than established visits (p < 0.001). This difference was largely driven by new CM visits (44.3 ± 13.7 minutes), which were significantly longer than established CM visits (29.8 ± 9.2 minutes; p = 0.001). CONCLUSIONS: TDABC may reveal opportunities to maximize value by highlighting instances of variability and high cost in each module of care delivery. Physician leaders in pediatric neurosurgery may be able to use this information to allocate costs and streamline value care pathways.

Influence of the living Pareto chart and data transparency on patient outcomes in neurosurgery.

OBJECTIVE: Quality improvement (QI) tools are increasingly being used to calibrate healthcare quality. Achieving healthcare quality is essential, as there is a movement toward value-based healthcare delivery. Visual management, such as a living Pareto chart, is a strategy for improvement within the QI framework. The authors herein hypothesized that transparency of data through a living Pareto chart is a powerful way to improve patient outcomes and gain clinical efficiency. METHODS: The authors retrospectively reviewed patient outcomes and complications; cerebrospinal fluid (CSF) leaks; shunt, baclofen, and other surgical site infections; readmission rates; and same- or next-day appointments in a cohort of patients at the Riley Hospital for Children from November 1, 2016, to May 31, 2020. Similarly, they reviewed neurosurgical outcomes and complications at a second institution, the Oklahoma Children's Hospital, where a living Pareto chart was utilized from February 1, 2021, to March 31, 2022. The discrete frequency and rates per month of outcomes and complications were graphed on scatterplots, Pearson correlation coefficients were calculated to measure the strength of the relationship between event frequency and time, and best-fit lines illustrated the relationship between those points through the least-squares method. RESULTS: At both the Riley Hospital for Children and Oklahoma Children's Hospital, the use of a living Pareto chart to display data transparently was associated with decreasing infections, and it was associated with decreasing readmissions at Riley. On the other hand, it encouraged same- or next-day clinic appointments to be offered to patients and families. Interestingly, CSF leaks were not mitigated with data transparency alone. CONCLUSIONS: Transparency is a driver of change in patient, provider, and institutional behaviors. It is an essential element of QI and patient safety, as well as building a culture of trust. Readmissions, infections, and same- or next-day appointments were influenced by the living Pareto chart; however, CSF leaks remained recalcitrant to data transparency. Other QI strategies may be necessary to positively affect the occurrence of CSF leaks in neurosurgery.

Establishment and characterization of patient-derived xenograft of a rare pediatric anaplastic pleomorphic xanthoastrocytoma (PXA) bearing a CDC42SE2-BRAF fusion.

Pleomorphic xanthoastrocytoma (PXA) is a rare subset of primary pediatric glioma with 70% 5-year disease free survival. However, up to 20% of cases present with local recurrence and malignant transformation into more aggressive type anaplastic PXA (AXPA) or glioblastoma. The understanding of disease etiology and mechanisms driving PXA and APXA are limited, and there is no standard of care. Therefore, development of relevant preclinical models to investigate molecular underpinnings of disease and to guide novel therapeutic approaches are of interest. Here, for the first time we established, and characterized a patient-derived xenograft (PDX) from a leptomeningeal spread of a patient with recurrent APXA bearing a novel CDC42SE2-BRAF fusion. An integrated -omics analysis was conducted to assess model fidelity of the genomic, transcriptomic, and proteomic/phosphoproteomic landscapes. A stable xenoline was derived directly from the patient recurrent tumor and maintained in 2D and 3D culture systems. Conserved histology features between the PDX and matched APXA specimen were maintained through serial passages. Whole exome sequencing (WES) demonstrated a high degree of conservation in the genomic landscape between PDX and matched human tumor, including small variants (Pearson's r = 0.794-0.839) and tumor mutational burden (~ 3 mutations/MB). Large chromosomal variations including chromosomal gains and losses were preserved in PDX. Notably, chromosomal gain in chromosomes 4-9, 17 and 18 and loss in the short arm of chromosome 9 associated with homozygous 9p21.3 deletion involving CDKN2A/B locus were identified in both patient tumor and PDX sample. Moreover, chromosomal rearrangement involving 7q34 fusion; CDC42SE-BRAF t (5;7) (q31.1, q34) (5:130,721,239, 7:140,482,820) was identified in the PDX tumor, xenoline and matched human tumor. Transcriptomic profile of the patient's tumor was retained in PDX (Pearson r = 0.88) and in xenoline (Pearson r = 0.63) as well as preservation of enriched signaling pathways (FDR Adjusted P < 0.05) including MAPK, EGFR and PI3K/AKT pathways. The multi-omics data of (WES, transcriptome, and reverse phase protein array (RPPA) was integrated to deduce potential actionable pathways for treatment (FDR < 0.05) including KEGG01521, KEGG05202, and KEGG05200. Both xenoline and PDX were resistant to the MEK inhibitors trametinib or mirdametinib at clinically relevant doses, recapitulating the patient's resistance to such treatment in the clinic. This set of APXA models will serve as a preclinical resource for developing novel therapeutic regimens for rare anaplastic PXAs and pediatric high-grade gliomas bearing BRAF fusions.

Neurosurgical Management of Spastic Conditions of the Upper Extremity.

Spasticity is a hypertonic segmental reflex pathway caused by a central nervous system injury. Spasticity of the upper extremity causes loss of function, joint contracture, pain, and poor cosmesis. Treatment aims to reduce or change the pathophysiology underlying the hyperactive reflex from dorsal sensory rootlets through the intrinsic machinery of the spinal cord to the neuromuscular junction. There are many treatments for upper extremity spasticity including oral medication, physiotherapy, intrathecal baclofen, and lesional or neuromodulatory surgical approaches. Goals of treatment must always be clearly defined, but neurosurgical management is most effective when paired with multidisciplinary therapies and caregiver participation.

Evaluation of lateral atlantodental interval asymmetry in the pediatric age group: normative values.

OBJECTIVE The revelation of normative radiographic measurements for the developing pediatric spine is incomplete. The purpose of this analysis was to determine the normal range of asymmetry of the lateral atlantodental interval (LADI) and define age- and sex-related differences. METHODS A total of 3072 children aged 0-18 years who underwent CT scanning of the cervical spine were identified at Riley Hospital for Children between 2005 and 2017. Patients were stratified by sex and age (in years) into 36 cohorts. Following this stratification, patients within each group were randomly selected for inclusion until 15 patients in each group had been measured (quota sampling). A total of 540 patients were included for study. Right and left linear measurements were performed in the CT axial plane at the C-1 midlateral mass level. RESULTS The overall mean difference between the right and left LADI was 0.09 ± 1.23 mm (range -6.05 to 4.87 mm). The magnitude of this asymmetry remained statistically insignificant across age groups (p = 0.278) and sex (p = 0.889). The intraclass correlation coefficient was 0.805 (95% CI 0.779-0.829). CONCLUSIONS Asymmetry of the LADI is not unusual in asymptomatic children. There is no appreciable difference in magnitude of this asymmetry across age ranges and sex. Measurement of LADI asymmetry shows "good" reliability and is easy to perform. Pediatric neurosurgeons, emergency department physicians, and radiologists should be aware of normative values of asymmetry when interpreting CT scans of the cervical spine. This may prevent unnecessary further workup with dynamic CT or MRI.

Simulation Training Curricula for Neurosurgical Residents: Cervical Foraminotomy and Durotomy Repair Modules.

INTRODUCTION: Since 2010, the Congress of Neurological Surgeons (CNS) has offered a neurosurgical skills simulation course for residents and medical students. The authors describe their experience with incorporation of two neurosurgical skills simulation modules into the dedicated resident training curriculum of a single ACGME-accredited training program, using lumbar dural repair (5) and posterior cervical laminoforaminotomy modules from the CNS simulation initiative (6). METHODS: Each of the available 22 neurosurgery residents at a single residency program was given two 20-question pretests for a cervical laminoforaminotomy and durotomy repair module as a basic test of regional anatomy, general disease knowledge, surgical decision making, and recently published literature. This was followed by a faculty-directed skills simulation course and concluded with a final 20 question post-test. RESULTS: Posterior cervical laminoforaminotomy was performed once by each resident, and grading was conducted using the predetermined OSATs. The overall score was 56.1 (70%, range 26-76, maximum 80 points) with a trend towards higher scores with advanced levels of training. All residents completed the durotomy repair OSATs for a total of three trials. Of a maximum composite score of 60, a mean 37.2 (62%, range 15-58) was scored by the residents (Table 3). The mean OSAT scores for each durotomy trial was 2.66, 3.15, and 3.48 on each success test. A trend towards higher scores in advanced years of training was observed, but did not reach statistical significance (Figure 3). CONCLUSIONS: Duty hour limitations and regulatory pressure for enhanced quality and outcomes may limit access of neurosurgical residents to fundamental skills training. Fundamental skills training as part of a validated simulation curriculum can mitigate this challenge to residency education. National development of effective technical simulation modules for use in individual residency training programs is a promising strategy to achieve these goals.

Long-term survival after gamma knife radiosurgery for primary and metastatic brain tumors.

In this paper, we studied factors related to long-term survival after gamma knife radiosurgery (GKS) for primary and metastatic brain tumors. We examined all cases of brain metastases and malignant glioma treated with GKS between September 1994 and December 1998. All patients with survival exceeding 2 years were studied retrospectively using prospectively acquired data. A total of 22 patients, with an average age of 56, were identified, which accounts for 11% of the total patients treated during this time interval. Seventeen of 22 are still alive with a mean follow-up of 48 months. Sixteen patients had metastatic tumors, whereas 6 had a malignant glioma. Thirteen of 15 patients with metastases had a controlled primary site, and the other 2 patients did not have a primary site identified. These 2 patients were among the 3 that died during the follow-up period. Fourteen patients developed symptomatic radiation necrosis by MRI criteria with 4 confirmed by biopsy. Quality-of-life factors were assessed in 20 of 22 patients using a modified Spitzer scale, which showed a high level of functioning in all of the long-term survivors (mean score 8.65 of 10), and only 1 patient had a Karnofsky Performance Score of less than 70. We conclude that radiosurgery provides a noninvasive and effective way of controlling brain tumors, while preserving quality of life.