Ultrasound as a standalone tool for the management of pediatric calvarial dermoid cysts.

PURPOSE: Calvarial dermoid and epidermoid cysts are benign lesions common in pediatric neurosurgery. Diagnosis is primarily clinical, with frequent but inconsistent use of imaging. Dermoids have been shown to possess distinct sonographic features, but ultrasound (US) remains underutilized in their management. The purpose of this study is to investigate the independent reliability of US in managing pediatric calvarial dermoids and distinguishing them from other calvarial lesions. METHODS: A retrospective review of consecutive patients ≤ 21 years of age with surgically resected calvarial masses between 2017-2024 was performed. Demographic, clinical, and imaging data were analyzed. Pearson chi-squared tests were used for comparison of categorical variables and a binomial linear model was generated controlling for age, lesion tenderness, growth, and suture location. RESULTS: Fifty-nine patients with 61 lesions (31 in females; median age 13 months) were included. Dermoids were more common in younger patients (median age 12 months), along suture lines, and were less likely to present with tenderness (p < 0.001) or rapid growth (p = 0.003). Ultrasound was used in 83% of cases and was the sole imaging modality in 33%. On multivariate analysis, suture location was a significant positive predictor of a dermoid diagnosis (OR = 8.08, 95% CI = 1.67-44.18), while rapid growth was a significant negative predictor (OR = 0.08, 95% CI = 0.003-0.80). CONCLUSION: Ultrasound presents a sensitive and reliable method for the evaluation of most pediatric calvarial lesions, especially dermoid cysts, and warrants being part of standard workup. With appropriate patient selection, US obviates the need for additional imaging in pediatric patients.

Imaging Features Predictive of Recurrence in Pediatric Intracranial Germ-Cell Tumors.

BACKGROUND/AIMS: Intracranial germ-cell tumors (GCTs) are a heterogeneous group of tumors that vary in their response to treatment. Standard treatment consists of chemotherapy and radiation therapy, with the consideration of second-look surgery in resistant disease. The present study aims to inform therapy by characterizing features on pretreatment imaging associated with recurrence. METHODS: Children with intracranial GCTs treated at a single institution between January 2000 and October 2016 were retrospectively reviewed under an Institutional Review Board-approved protocol. Imaging variables identified on pretreatment imaging were calcifications, cysts, heterogeneity of enhancement, blood products, hydrocephalus, gradient echo susceptibility, restricted diffusion, invasiveness, and extent of edema. Tumor recurrence was used as the primary outcome variable. RESULTS AND CONCLUSION: Fifty-two patients (39 males, mean age at diagnosis: 13 ± 5 years, 34 germinoma, 18 nongerminomatous GCT [NGGCT]) were reviewed. Thirty-three percent of the patients reviewed had recurrence (7 germinoma, 11 NGGCT). Recurrence was associated with invasiveness as seen on preoperative imaging (p = 0.0385) and cystic tumor (p = 0.048).

Parylene MEMS patency sensor for assessment of hydrocephalus shunt obstruction.

Neurosurgical ventricular shunts inserted to treat hydrocephalus experience a cumulative failure rate of 80 % over 12 years; obstruction is responsible for most failures with a majority occurring at the proximal catheter. Current diagnosis of shunt malfunction is imprecise and involves neuroimaging studies and shunt tapping, an invasive measurement of intracranial pressure and shunt patency. These patients often present emergently and a delay in care has dire consequences. A microelectromechanical systems (MEMS) patency sensor was developed to enable direct and quantitative tracking of shunt patency in order to detect proximal shunt occlusion prior to the development of clinical symptoms thereby avoiding delays in treatment. The sensor was fabricated on a flexible polymer substrate to eventually allow integration into a shunt. In this study, the sensor was packaged for use with external ventricular drainage systems for clinical validation. Insights into the transduction mechanism of the sensor were obtained. The impact of electrode size, clinically relevant temperatures and flows, and hydrogen peroxide (H2O2) plasma sterilization on sensor function were evaluated. Sensor performance in the presence of static and dynamic obstruction was demonstrated using 3 different models of obstruction. Electrode size was found to have a minimal effect on sensor performance and increased temperature and flow resulted in a slight decrease in the baseline impedance due to an increase in ionic mobility. However, sensor response did not vary within clinically relevant temperature and flow ranges. H2O2 plasma sterilization also had no effect on sensor performance. This low power and simple format sensor was developed with the intention of future integration into shunts for wireless monitoring of shunt state and more importantly, a more accurate and timely diagnosis of shunt failure.

Infection rate correlated with time to repair of open neural tube defects (myelomeningoceles): an institutional and national study.

BACKGROUND: The optimal time to closure of a newborn with an open neural tube defect (NTD-myelomeningocele) has been the subject of a number of investigations. One aspect of timing that has received attention is its relationship to repair site and central nervous system (CNS) infection that can lead to irreversible deficits and prolonged hospital stays. No studies have evaluated infection as a function of surgical timing at a national level. We hypothesized an increase in wound infection in those patients with delays in myelomeningocele repair when evaluated in both a single-center and national database. METHODS: Treatment outcomes following documented times to transfer and closure were evaluated at Children's Hospital of Los Angeles (CHLA) for the years 2004 to 2014. Data of newborns with a myelomeningocele with varying time to repair were also obtained from non-overlapping abstracts of the 2000-2010 Kids' Inpatient Database (KID) and Nationwide Inpatient Sample (NIS). Poisson multivariable regression analyses were used to assess the effect of time to repair on infection and time to discharge. RESULTS: At CHLA, 95 neonates who underwent myelomeningocele repair were identified, with a median time from birth to treatment of 1 day. Six (6 %) patients were noted to have postrepair complications. CHLA data was not sufficiently powered to detect a difference in infection following delay in closure. In the NIS, we identified 3775 neonates with repaired myelomeningocele of whom infection was reported in 681 (18 %) patients. There was no significant difference in rates of infection between same-day and 1-day wait times (p = 0.22). Wait times of two (RR = 1.65 [1.23, 2.22], p < 0.01) or more days (RR = 1.88 [1.39, 2.54], p < 0.01), respectively, experienced a 65 % and 88 increase in rates of infection compared to same-day procedures. Prolonged wait time was 32 % less likely at facilities with increased myelomeningocele repair volume (RR = 0.68 [0.56 0.83], p < 0.01). The presence of infection was associated with a 54 % (RR = 1.54 [1.36, 1.74], p < 0.01) increase in the length of stay when compared to neonates without infection. CONCLUSION: Myelomeningocele closure, when delayed more than 1 day after birth, is associated with an increased rate of infection and length of stay in the national cohort. High-volume centers are associated with fewer delays to repair. Though constrained by limitations of a national coded database, these results suggest that early myelomeningocele repair decreases the rate of infection.

Versatile utilization of real-time intraoperative contrast-enhanced ultrasound in cranial neurosurgery: technical note and retrospective case series.

OBJECTIVE: Intraoperative contrast-enhanced ultrasound (iCEUS) offers dynamic imaging and provides functional data in real time. However, no standardized protocols or validated quantitative data exist to guide its routine use in neurosurgery. The authors aimed to provide further clinical data on the versatile application of iCEUS through a technical note and illustrative case series. METHODS: Five patients undergoing craniotomies for suspected tumors were included. iCEUS was performed using a contrast agent composed of lipid shell microspheres enclosing perflutren (octafluoropropane) gas. Perfusion data were acquired through a time-intensity curve analysis protocol obtained using iCEUS prior to biopsy and/or resection of all lesions. RESULTS: Three primary tumors (gemistocytic astrocytoma, glioblastoma multiforme, and meningioma), 1 metastatic lesion (melanoma), and 1 tumefactive demyelinating lesion (multiple sclerosis) were assessed using real-time iCEUS. No intraoperative complications occurred following multiple administrations of contrast agent in all cases. In all neoplastic cases, iCEUS replicated enhancement patterns observed on preoperative Gd-enhanced MRI, facilitated safe tumor debulking by differentiating neoplastic tissue from normal brain parenchyma, and helped identify arterial feeders and draining veins in and around the surgical cavity. Intraoperative CEUS was also useful in guiding a successful intraoperative needle biopsy of a cerebellar tumefactive demyelinating lesion obtained during real-time perfusion analysis. CONCLUSIONS: Intraoperative CEUS has potential for safe, real-time, dynamic contrast-based imaging for routine use in neurooncological surgery and image-guided biopsy. Intraoperative CEUS eliminates the effect of anatomical distortions associated with standard neuronavigation and provides quantitative perfusion data in real time, which may hold major implications for intraoperative diagnosis, tissue differentiation, and quantification of extent of resection. Further prospective studies will help standardize the role of iCEUS in neurosurgery.

Risk factors associated with the surgical management of craniopharyngiomas in pediatric patients: analysis of 1961 patients from a national registry database.

OBJECTIVE Patient demographic characteristics, hospital volume, and admission status have been shown to impact surgical outcomes of sellar region tumors in adults; however, the data available following the resection of craniopharyngiomas in the pediatric population remain limited. The authors sought to identify potential risk factors associated with outcomes following surgical management of pediatric craniopharyngiomas. METHODS The Nationwide Inpatient Sample database and Kids' Inpatient Database were analyzed to include admissions for pediatric patients (≤ 18 years) who underwent a transcranial or transsphenoidal craniotomy for resection of a craniopharyngioma. Patient-level factors, including age, race, comorbidities, and insurance type, as well as hospital factors were collected. Outcomes analyzed included mortality rate, endocrine and nonendocrine complications, hospital charges, and length of stay. A multivariate model controlling for variables analyzed was constructed to examine significant independent risk factors. RESULTS Between 2000 and 2011, 1961 pediatric patients were identified who underwent a transcranial (71.2%) or a transsphenoidal (28.8%) craniotomy for resection of a craniopharyngioma. A major predilection for age was observed with the selection of a transcranial (23.4% in < 7-year-olds, 28.1% in 7- to 12-year-olds, and 19.7% in 13- to 18-year-olds) versus transphenoidal (2.9% in < 7-year-olds, 7.4% in 7- to 12-year-olds, and 18.4% in 13- to 18-year-olds) approach. No significant outcomes were associated with a particular surgical approach, except that 7- to 12-year-old patients had a higher risk of nonendocrine complications (relative risk [RR] 2.42, 95% CI 1.04-5.65, p = 0.04) with the transsphenoidal approach when compared with 13- to 18-year-old patients. The overall inpatient mortality rate was 0.5% and the most common postoperative complication was diabetes insipidus (64.2%). There were no independent factors associated with inpatient mortality rates and no significant differences in outcomes among groups based on sex and race. The average length of stay was 11.8 days, and the mean hospital charge was $116,5 22. Hospitals with medium and large bed capacity were protective against nonendocrine complications (RR 0.53, 95% CI 0.3-0.93, p = 0.03 [medium]; RR 0.45, 95% CI 0.25-0.8, p < 0.01 [large]) and total complications (RR 0.73, 95% CI 0.55-0.97, p = 0.03 [medium]; RR 0.68, 95% CI 0.51-0.9, p < 0.01 [large]) when compared with hospitals with small bed capacity (< 200 beds). Patients admitted to rural hospitals had an increased risk for nonendocrine complications (RR 2.56, 95% CI 1.11-5.9, p = 0.03). The presence of one or more medical comorbidities increased the risk of higher total complications (RR 1.38, 95% CI 1.14-1.68), p < 0.01 [1 comorbidity]; RR 2.37, 95% CI 1.98-2.84, p < 0.01 [≥ 2 comorbidities]) and higher total hospital charges (RR 2.9, 95% CI 1.08-7.81, p = 0.04 [1 comorbidity]; RR 9.1, 95% CI 3.74-22.12, p < 0.01 [≥ 2 comorbidities]). CONCLUSIONS This analysis identified patient age, comorbidities, insurance type, hospital bed capacity, and rural or nonteaching hospital status as independent risk factors for postoperative complications and/or increased hospital charges in pediatric patients with craniopharyngioma. Transsphenoidal surgery in younger patients with craniopharyngioma was a risk factor for nonendocrine complications.

Intracranial hypertension after surgical correction for craniosynostosis: a systematic review.

OBJECT The authors' aim was perform a systematic review on the incidence of intracranial hypertension (IH) after surgery for craniosynostosis. METHODS A systematic literature review was conducted using PubMed to assess the rate of postoperative IH in studies published between 1985 and 2014. Inclusion criteria were 1) English-language literature; 2) human subjects; 3) pediatric cases; and 4) postoperative IH confirmed with invasive intracranial pressure monitoring. RESULTS Seven studies met inclusion criteria. IH was reported to be present in 5% of patients postoperatively with sagittal synostosis and 4% of patients with all forms of nonsyndromic craniosynostosis. Inadequate numbers were available to determine the incidence of postoperative IH for syndromic and individual nonsyndromic sutural synostosis based on the inclusion criteria. Surgical groups were subdivided into cranial remodeling procedures without orbital advancement and craniofacial procedures with orbital advancement. IH was reported to be present in 5% of patients with all forms of nonsyndromic sutural stenosis after cranial remodeling procedures and 1% after craniofacial advancement. CONCLUSIONS Postoperative development of elevated intracranial pressure has been described by multiple institutions, but the variation in how IH is determined and the multiple surgical procedures to correct craniosynostosis has limited the number of studies subject to a meta-analysis. Nonetheless, this entity deserves special attention, and further studies are required to determine the true incidence of postoperative IH, including the role of various surgical procedures on its incidence. The long-term consequences of chronic IH in this group of patients also need to be evaluated.

Endoscopic endonasal transsphenoidal surgery: implementation of an operative and perioperative checklist.

Endoscopic endonasal surgery relies heavily on specialized operative instrumentation and optimization of endocrinological and other critical adjunctive intraoperative factors. Several studies and worldwide initiatives have previously established that intraoperative and perioperative surgical checklists can minimize the incidence of and prevent adverse events. The aim of this article was to outline some of the most common considerations in the perioperative and intraoperative preparation for endoscopic endonasal transsphenoidal surgery. The authors implemented and prospectively evaluated a customized checklist at their institution in 25 endoscopic endonasal operations for a variety of sellar and skull base pathological entities. Although no major errors were detected, near misses pertaining primarily to missing components of surgical equipment or instruments were identified in 9 cases (36%). The considerations in the checklist provided in this article can serve as a basic template for further customization by centers performing endoscopic endonasal surgery, where their application may reduce the incidence of adverse or preventable errors associated with surgical treatment of sellar and skull base lesions.

Deep brain stimulation: a mechanistic and clinical update.

Deep brain stimulation (DBS), the practice of placing electrodes deep into the brain to stimulate subcortical structures with electrical current, has been increasing as a neurosurgical procedure over the past 15 years. Originally a treatment for essential tremor, DBS is now used and under investigation across a wide spectrum of neurological and psychiatric disorders. In addition to applying electrical stimulation for clinical symptomatic relief, the electrodes implanted can also be used to record local electrical activity in the brain, making DBS a useful research tool. Human single-neuron recordings and local field potentials are now often recorded intraoperatively as electrodes are implanted. Thus, the increasing scope of DBS clinical applications is being matched by an increase in investigational use, leading to a rapidly evolving understanding of cortical and subcortical neurocircuitry. In this review, the authors discuss recent innovations in the clinical use of DBS, both in approved indications as well as in indications under investigation. Deep brain stimulation as an investigational tool is also reviewed, paying special attention to evolving models of basal ganglia and cortical function in health and disease. Finally, the authors look to the future across several indications, highlighting gaps in knowledge and possible future directions of DBS treatment.

Deep brain stimulation in children and young adults with secondary dystonia: the Children's Hospital Los Angeles experience.

BACKGROUND: Dystonia is a movement disorder in which involuntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both. It can be classified as primary or secondary. There is no cure for dystonia and the goal of treatment is to provide a better quality of life for the patient. Surgical intervention is considered for patients in whom an adequate trial of medical treatment has failed. Deep brain stimulation (DBS), specifically of the globus pallidus interna (GPi), has been shown to be extremely effective in primary generalized dystonia. There is much less evidence for the use of DBS in patients with secondary dystonia. However, given the large number of patients with secondary dystonia, the significant burden on the patients and their families, and the potential for DBS to improve their functional status and comfort level, it is important to continue to investigate the use of DBS in the realm of secondary dystonia. OBJECT: The objective of this study is to review a series of cases involving patients with secondary dystonia who have been treated with pallidal DBS. METHODS: A retrospective review of 9 patients with secondary dystonia who received treatment with DBS between February 2011 and February 2013 was performed. Preoperative and postoperative videos were scored using the Barry-Albright Dystonia Scale (BADS) and Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) by a neurologist specializing in movement disorders. In addition, the patients' families completed a subjective questionnaire to assess the perceived benefit of DBS. RESULTS: The average age at DBS unit implantation was 15.1 years (range 6-20 years). The average time to follow-up for the BADS evaluation from battery implantation was 3.8 months (median 3 months). The average time to follow-up for the subjective benefit evaluation was 10.6 months (median 9.5 months). The mean BADS scores improved by 9% from 26.5 to 24 (p = 0.04), and the mean BFMDRS scores improved by 9.3% (p = 0.055). Of note, even in patients with minimal functional improvement, there seemed to be decreased contractures and spasms leading to improved comfort. There were no complications such as infections or hematoma in this case series. In the subjective benefit evaluation, 3 patients' families reported "good" benefit, 4 reported "minimal" benefit, and 1 reported no benefit. CONCLUSIONS: These early results of GPi stimulation in a series of 9 patients suggest that DBS is useful in the treatment of secondary generalized dystonia in children and young adults. Objective improvements in BADS and BFMDRS scores are demonstrated in some patients with generalized secondary dystonia but not in others. Larger follow-up studies of DBS for secondary dystonia, focusing on patient age, history, etiology, and patterns of dystonia, are needed to learn which patients will respond best to DBS.

Ventriculopleural shunts in a pediatric population: a review of 170 consecutive patients.

OBJECTIVE: The authors sought to determine the outcome of using the pleural space as the terminus for ventricular CSF-diverting shunts in a pediatric population. METHODS: All ventriculopleural (VPl) shunt insertions or revisions done between 1978 and 2018 in patients at Children's Hospital Los Angeles were identified. Data recorded for analysis were age, sex, weight, etiology of hydrocephalus, previous shunt history, reason for VPl shunt insertion or conversion from a ventriculoperitoneal (VP) or ventriculoatrial (VA) shunt, valve type, nature of malfunction, presence of shunt infection or pleural effusion, and conversion to a different distal site. RESULTS: A total of 170 patients (mean age 14 ± 4 years) with a VPl shunt who were followed up for a mean of 57 ± 53 months were identified. The reasons for conversion to a VPl shunt for 167 patients were previous shunt infection in 57 (34%), multiple abdominal procedures in 44 (26%), inadequate absorption of CSF in 34 (20%), abdominal pseudocyst in 25 (15%), and obesity in 7 (4%). No VPl revisions were required in 97 (57%) patients. Of the 73 (43%) patients who did require revision, the most common reason was proximal obstruction in 32 (44%). The next most frequent complication was pleural effusion in 22 (30%) and included 3 patients with shunt infection. All 22 patients with a clinically significant pleural effusion required changing the distal end of the shunt from the pleural space. Pleural effusion was more likely to occur in VPl shunts without an antisiphon valve. Of the 29 children < 10 years old, 7 (24%) developed a pleural effusion requiring a revision of the distal catheter to outside the pleural space compared with 15 (11%) who were older (p = 0.049). There were 14 shunt infections with a rate of 4.2% per procedure and 8.2% per patient. CONCLUSIONS: VPl shunts in children younger than 10 years of age have a significantly higher rate of symptomatic pleural effusion, requiring revision of the shunt's terminus to a different location. VPl shunt complication rates are similar to those of VP shunts. The technical difficulty of inserting a VPl shunt is comparable to that of a VP shunt. In a patient older than 10 years, all else being equal, the authors recommend that the distal end of a shunt be placed into the pleural space rather than the right atrium if the peritoneal cavity is not suitable.

Pediatric sellar solitary fibrous tumor/ hemangiopericytoma: A rare case report and review of the literature.

BACKGROUND: Solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is a rare tumor which originates from the walls of capillaries and has historically been thought to be able to occur anywhere in the body that blood vessels are found. It is rarely found in the sellar region. CASE DESCRIPTION: InS this report, we present the first case of this tumor occurring in the sellar region of a pediatric patient. This 12-year-old male presented with progressive vision loss which prompted surgical resection after a sellar lesion was discovered on imaging. The initial transsphenoidal approach resulted in subtotal resection and the patient experienced reoccurrence within 3 months. He underwent an orbitozygomatic craniotomy to achieve gross total tumor resection. CONCLUSION: We conducted a literature review of intracranial SFT/HPC in the pediatric population and found it to be an extremely rare occurrence, with <30 cases reported. The incidence of SFT/HPC occurring in the sellar region for any age group was also found to be a rare entity. Treatment recommendations for this tumor are also scarce, based on retrospective chart reviews from the adult population. The role for adjuvant radiation has mixed results.

Fenestrated aneurysm clips in the surgical management of anterior communicating artery aneurysms: operative techniques and strategy. Clinical article.

OBJECT: Aneurysms of the anterior communicating artery (ACoA) can be a considerable challenge to treat surgically based on variations in the anatomy and morphological features of the ACoA complex. The fenestrated aneurysm clip can be a simple and practical tool in the operative management of ACoA aneurysms. The goal in this study was to characterize the particular surgical situations in which the use of a fenestrated clip facilitates the clip ligation of ACoA aneurysms. METHODS: The authors present their operative strategy and techniques for the use of fenestrated clips in the treatment of ACoA aneurysms. RESULTS: One hundred ninety-nine patients underwent surgical clipping of an ACoA aneurysm at the authors' institution between the years 1991 and 2008. Of these patients, fenestrated aneurysm clips were used in 20 cases (10%). The following structures were enclosed in the clip aperture: ipsilateral A(2) artery, 12 patients (60%); ipsilateral A(1) artery, 4 patients (20%); ipsilateral A(1) artery plus recurrent artery of Heubner, 1 patient (5%); ACoA, 1 patient (5%); frontopolar artery, 1 patient (5%); and no structures, 1 patient (5%). Aneurysms approached from the left side more frequently required fenestrated clips than did right-sided aneurysms (80 vs 20%, p = 0.0073). In all cases, patency of the A(2) vessels was confirmed on postoperative angiography. In 2 patients, small remnant aneurysm necks were identified on postoperative angiography. CONCLUSIONS: The use of fenestrated aneurysm clips can minimize tedious and potentially dangerous dissection of adherent branch vessels, while maintaining the integrity of structures placed within the clip aperture. The ACoA aneurysms pointing in a superior direction are more likely to require clip fenestration around the A(2) vessel, whereas those pointing in an inferior direction are more likely to require clip fenestration around the A(1) vessel. The parallel approximation of the fenestrated clip blades makes them especially useful in the treatment of large or giant aneurysms.

Risk Factors for Preoperative Developmental Delay in Patients with Nonsyndromic Sagittal Craniosynostosis.

BACKGROUND: Some patients with isolated sagittal craniosynostosis have demonstrated mild neurodevelopmental delays. This study examined potential preoperative risk factors for developmental delay. METHODS: Patients completed preoperative Bayley Scales of Infant and Toddler Development, Third Edition, and medical records were reviewed. Multivariate analyses of covariance and correlations were calculated. RESULTS: Participants (n = 77) were predominantly male (77.9 percent) and were aged 2 to 12 months (mean, 5.1 ± 2.3 months). Patients were classified with no delays [n = 63 (82 percent)] or delays [n = 14 (18 percent)] in one or more developmental area(s). There were no group sociodemographic differences. Prenatally, patients with delays versus no delays had lower mean gestational age in weeks (36.9 ± 2.8 weeks versus 39.1 ± 1.7 weeks; p = 0.001) with higher rates of gestational diabetes (36 percent versus 5 percent; p = 0.006) and premature rupture of membranes (14 percent versus 2 percent; p = 0.026). At birth, patients with delays had lower mean birth weight (2982 ± 714 g versus 3374 ± 544 g; p = 0.053), higher rates of respiratory distress (29 percent versus 5 percent; p = 0.005), additional medical diagnoses (57 percent versus 13 percent; p = 0.001), and longer mean neonatal intensive care unit stays (1.4 ± 1.8 weeks versus 0.2 ± 0.9 week; p = 0.002). Variables differing by group had moderate correlations. CONCLUSIONS: Patients with nonsyndromic sagittal craniosynostosis that had delays in development had lower gestational age and birth weight, with more prenatal and birth complications. These factors can help identify patients who might be at risk for delay and need close monitoring. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Utility of depth electrode placement in the neurosurgical management of bottom-of-sulcus lesions: technical note.

OBJECTIVE: Small lesions at the depth of the sulcus, such as with bottom-of-sulcus focal cortical dysplasia, are not visible from the surface of the brain and can therefore be technically challenging to resect. In this technical note, the authors describe their method of using depth electrodes as landmarks for the subsequent resection of these exacting lesions. METHODS: A retrospective review was performed on pediatric patients who had undergone invasive electroencephalography with depth electrodes that were subsequently used as guides for resection in the period between July 2015 and June 2017. RESULTS: Ten patients (3-15 years old) met the criteria for this study. At the same time as invasive subdural grid and/or strip insertion, between 2 and 4 depth electrodes were placed using a hand-held frameless neuronavigation technique. Of the total 28 depth electrodes inserted, all were found within the targeted locations on postoperative imaging. There was 1 patient in whom an asymptomatic subarachnoid hemorrhage was demonstrated on postprocedural imaging. Depth electrodes aided in target identification in all 10 cases. CONCLUSIONS: Depth electrodes placed at the time of invasive intracranial electrode implantation can be used to help localize, target, and resect primary zones of epileptogenesis caused by bottom-of-sulcus lesions.

A review of selective hypothermia in the management of traumatic brain injury.

OBJECT: Traumatic brain injury (TBI) remains a significant cause of morbidity and death in the US and worldwide. Resuscitative systemic hypothermia following TBI has been established as an effective neuroprotective treatment in multiple studies in animals and humans, although this intervention carries with it a significant risk profile as well. Selective, or preferential, methods of inducing cerebral hypothermia have taken precedence over the past few years in order to minimize systemic adverse effects. In this report, the authors explore the current methods available for inducing selective cerebral hypothermia following TBI and review the literature regarding the results of animal and human trials in which these methods have been implemented. METHODS: A search of the PubMed archive (National Library of Medicine) and the reference lists of all relevant articles was conducted to identify all animal and human studies pertaining to the use of selective brain cooling, selective hypothermia, preferential hypothermia, or regional hypothermia following TBI. RESULTS: Multiple methods of inducing selective cerebral hypothermia are currently in the experimental phases, including surface cooling, intranasal selective hypothermia, transarterial or transvenous endovascular cooling, extraluminal vascular cooling, and epidural cerebral cooling. CONCLUSIONS: Several methods of conferring preferential neuroprotection via selective hypothermia currently are being tested. Class I prospective clinical trials are required to assess the safety and efficacy of these methods.

Development of a Perfusion-Based Cadaveric Simulation Model Integrated into Neurosurgical Training: Feasibility Based On Reconstitution of Vascular and Cerebrospinal Fluid Systems.

BACKGROUND: Novel methodologies providing realistic simulation of the neurosurgical operating room environment are currently needed, particularly for highly subspecialized operations with steep learning curves, high-risk profiles, and demands for advanced psychomotor skills. OBJECTIVE: To describe the development of a curriculum for using perfusion-based cadaveric simulation models in a "Mock Operating Room" for neurosurgical procedures. METHODS: At the USC Keck School of Medicine Fresh Tissue Dissection Laboratory between 2012 and 2016, 43 cadaveric specimens underwent cannulation of the femoral or carotid artery and artificial perfusion of the arterial system, and/or cannulation of the intradural cervical spine for intrathecal reconstitution of the cerebrospinal fluid (CSF) system. Models were used to train neurosurgical residents in various procedures. Self-assessment of pre- and postprocedure trainee confidence (Likert) scores was compared for each module. RESULTS: The following novel procedural training methodologies were successfully established: management of an injury to the carotid artery during an endoscopic endonasal approach (n = 12), endoscopic endonasal CSF leak repair (n = 6) with fluorescein perfusion, carotid endarterectomy (n = 4), extracranial-to-intracranial bypass (n = 2), insertion of ventriculostomy catheter (n = 7), spinal laminectomy with durotomy repair (n = 9), and intraventricular neuro-endoscopy with septum pellucidotomy and third ventriculostomy (n = 12). In all instances, trainees reported improvement in their postprocedural confidence scores, with mean pre- and postprocedural Likert scores being 2.85 ± 1.09 and 4.14 ± 0.93 (P < .05). CONCLUSION: Augmentation of fresh cadaveric specimens via reconstitution of vascular and CSF pathways is a feasible methodology for complimenting surgical training in numerous neurosurgical procedures, and may hold implications in the future of neurosurgical resident education.

Perfusion-based human cadaveric specimen as a simulation training model in repairing cerebrospinal fluid leaks during endoscopic endonasal skull base surgery.

OBJECTIVE Competency in endoscopic endonasal approaches (EEAs) to repair high-flow cerebrospinal fluid (CSF) leaks is an essential component of the neurosurgical training process. The objective of this study was to demonstrate the feasibility of a simulation model for EEA repair of anterior skull base CSF leaks. METHODS Human cadaveric specimens were utilized with a perfusion system to simulate a high-flow CSF leak. Neurological surgery residents (postgraduate year 3 or greater) performed a standard EEA to repair a CSF leak using a combination of fat, fascia lata, and pedicled nasoseptal flaps. A standardized 5-point Likert questionnaire was used to assess the knowledge gained, techniques learned, degree of safety, benefit of CSF perfusion during repair, and pre- and posttraining confidence scores. RESULTS Intrathecal perfusion of fluorescein-infused saline into the ventricular/subarachnoid space was successful in 9 of 9 cases. The addition of CSF reconstitution offered the residents visual feedback for confirmation of intraoperative CSF leak repair. Residents gained new knowledge and a realistic simulation experience by rehearsing the psychomotor skills and techniques required to repair a CSF leak with fat and fascial grafts, as well as to prepare and rotate vascularized nasoseptal flaps. All trainees reported feeling safer with the procedure in a clinical setting and higher average posttraining confidence scores (pretraining 2.22 ± 0.83, posttraining 4.22 ± 0.44, p < 0.001). CONCLUSIONS Perfusion-based human cadaveric models can be utilized as a simulation training model for repairing CSF leaks during EEA.

The effect of NACHRI children's hospital designation on outcome in pediatric malignant brain tumors.

OBJECTIVE Although current pediatric neurosurgery guidelines encourage the treatment of pediatric malignant brain tumors at specialized centers such as pediatric hospitals, there are limited data in support of this recommendation. Previous studies suggest that children treated by higher-volume surgeons and higher-volume hospitals may have better outcomes, but the effect of treatment at dedicated children's hospitals has not been investigated. METHODS The authors analyzed the Healthcare Cost and Utilization Project Kids' Inpatient Database (KID) from 2000-2009 and included all patients undergoing a craniotomy for malignant pediatric brain tumors based on ICD-9-CM codes. They investigated the effects of patient demographics, tumor location, admission type, and hospital factors on rates of routine discharge and mortality. RESULTS From 2000 through 2009, 83.6% of patients had routine discharges, and the in-hospital mortality rate was 1.3%. In multivariate analysis, compared with children treated at an institution designated as a pediatric hospital by NACHRI (National Association of Children's Hospitals and Related Institutions), children receiving treatment at a pediatric unit within an adult hospital (OR 0.5, p < 0.01) or a general hospital without a designated pediatric unit (OR 0.4, p < 0.01) were less likely to have routine discharges. Treatment at a large hospital (> 400 beds; OR 1.8, p = 0.02) and treatment at a teaching hospital (OR 1.7, p = 0.02) were independently associated with greater likelihood of routine discharge. However, patients transferred between facilities had a significantly decreased likelihood of routine discharge (OR 0.5, p < 0.01) and an increased likelihood of mortality (OR 5.0, p < 0.01). Procedural volume was not associated with rate of routine discharge or mortality. CONCLUSIONS These findings may have implications for planning systems of care for pediatric patients with malignant brain tumors. The authors hope to motivate future research into the specific factors that may lead to improved outcomes at designated pediatric hospitals.