Safety and Technical Efficacy of Pediatric Brainstem Biopsies: An Updated Meta-Analysis of 1000+ Children.

BACKGROUND: Brainstem tumors represent ∼10% of pediatric brain tumors, ∼80% of these are diffuse midline glioma (DMG). Given invariably poor prognosis in DMG, there continues to be immense variation worldwide in performing biopsy of these lesions. Several contemporary studies in recent years have provided new data to elucidate the safety profile of biopsy and an updated meta-analysis is thus indicated. METHODS: We found 29 studies of pediatric brainstem biopsy in the last 20 years (2003-2023, 1002 children). We applied meta-analysis of proportions using a random-effects model to generate point estimates, confidence intervals, and measures of heterogeneity. RESULTS: 87% of procedures were stereotactic needle biopsies (of these, 62% with a frame, 14% without frame, and 24% robotic.) Biopsy resulted in a histological diagnosis ("technical yield") in 96.8% of cases (95% CI 95.4-98.2). Temporary complications were seen in 6% (95 CI 4-8), with the most common neurological complications being 1) cranial nerve dysfunction, 2) worsening or new ataxia, and 3) limb weakness. Permanent complications (excluding death) were seen in 1% (95% CI 0.5-2), most commonly including cranial nerve dysfunction and limb weakness. 5 deaths were reported in the entire pooled cohort of 1002 children (0.5%). CONCLUSIONS: When counseling families on the merits of brainstem biopsy in children, it is reasonable to state that permanent morbidity is rare (<2%). If biopsy is performed specifically to facilitate enrollment in clinical trials requiring a molecular diagnosis, the risks of biopsy outlined here should be weighed against potential benefits of trial enrollment.

Maintaining Human Glioblastoma Cellular Diversity Ex vivo using Three-Dimensional Organoid Culture.

Glioblastoma (GBM) is the most commonly occurring primary malignant brain cancer with an extremely poor prognosis. Intra-tumoral cellular and molecular diversity, as well as complex interactions between tumor microenvironments, can make finding effective treatments a challenge. Traditional adherent or sphere culture methods can mask such complexities, whereas three-dimensional organoid culture can recapitulate regional microenvironmental gradients. Organoids are a method of three-dimensional GBM culture that better mimics patient tumor architecture, contains phenotypically diverse cell populations, and can be used for medium-throughput experiments. Although three-dimensional organoid culture is more laborious and time-consuming compared to traditional culture, it offers unique benefits and can serve to bridge the gap between current in vitro and in vivo systems. Organoids have established themselves as invaluable tools in the arsenal of cancer biologists to better understand tumor behavior and mechanisms of resistance, and their applications only continue to grow. Here, details are provided about methods for generating and maintaining GBM organoids. Instructions of how to perform organoid sample embedding and sectioning using both frozen and paraffin-embedding techniques, as well as recommendations for immunohistochemistry and immunofluorescence protocols on organoid sections, and measurement of total organoid cell viability, are all also described.

Three-dimensional organoid culture unveils resistance to clinical therapies in adult and pediatric glioblastoma.

BACKGROUND: Glioblastoma (GBM) is the most common primary brain tumor with a dismal prognosis. The inherent cellular diversity and interactions within tumor microenvironments represent significant challenges to effective treatment. Traditional culture methods such as adherent or sphere cultures may mask such complexities whereas three-dimensional (3D) organoid culture systems derived from patient cancer stem cells (CSCs) can preserve cellular complexity and microenvironments. The objective of this study was to determine if GBM organoids may offer a platform, complimentary to traditional sphere culture methods, to recapitulate patterns of clinical drug resistance arising from 3D growth. METHODS: Adult and pediatric surgical specimens were collected and established as organoids. We created organoid microarrays and visualized bulk and spatial differences in cell proliferation using immunohistochemistry (IHC) staining, and cell cycle analysis by flow cytometry paired with 3D regional labeling. We tested the response of CSCs grown in each culture method to temozolomide, ibrutinib, lomustine, ruxolitinib, and radiotherapy. RESULTS: GBM organoids showed diverse and spatially distinct proliferative cell niches and include heterogeneous populations of CSCs/non-CSCs (marked by SOX2) and cycling/senescent cells. Organoid cultures display a comparatively blunted response to current standard-of-care therapy (combination temozolomide and radiotherapy) that reflects what is seen in practice. Treatment of organoids with clinically relevant drugs showed general therapeutic resistance with drug- and patient-specific antiproliferative, apoptotic, and senescent effects, differing from those of matched sphere cultures. CONCLUSIONS: Therapeutic resistance in organoids appears to be driven by altered biological mechanisms rather than physical limitations of therapeutic access. GBM organoids may therefore offer a key technological approach to discover and understand resistance mechanisms of human cancer cells.

Cranial Vault Remodeling in Children With Ventricular Shunts.

INTRODUCTION: Cranial vault surgery in children with ventricular shunts is more complex due to the possible interference of shunt location with surgical planning and increased risk of shunt related complications. The study evaluated the management of ventricular shunts during cranial vault remodeling (CVR) and subsequent outcomes and complications following CVR. METHODS: An IRB-approved retrospective chart review was performed including patients who underwent CVR in presence of a ventricular shunt. Measured outcomes were number of shunt revisions following CVR, 30-day complication rate, 3-month complication rate, and post-CVR Whitaker classification. Finally, a review of the literature was performed, and our results were compared to previous reports. RESULTS: Eleven patients met the inclusion criteria. Ventricular shunt was not exposed in 18%; exposed and not revised in 54%; exposed and left on a bone peninsula in 18% and simultaneously exposed and revised in 18%. Two patients experienced complications within 30-days. Three additional patients experienced complications within 3-months. An average of 2.2 shunt revisions per patient were performed following CVR. Whitaker classification was I in 7 patients, II in 1 patient and III in 2 patients. Shunt revision rate for patients undergoing CVR for hydrocephalic macrocephaly was on average of 1.2 and 1.9 for shunt-induced craniosynostosis in literature. CONCLUSIONS: Cranial vault abnormalities in the presence of a ventricular shunt can be effectively treated with CVR. The presence of a shunt does not seem to interfere with final head shape. While leaving the shunt unexposed may appear less morbid, shunt related complications can still occur with this approach.

Reconstruction of Secondary Calvarial Defects with Ex Situ Split Calvarial Bone Grafts: Long-Term Evaluation of Outcomes.

BACKGROUND: Autologous bone continues to represent the first choice for reconstruction of calvarial defects. However, unanswered questions remain on the natural history of the graft and the influence of patient-related risk factors. This study investigated the outcomes of skull reconstruction with split calvarial bone graft, examining the natural history and stratifying the risk of unfavorable results. METHODS: Patients who underwent cranioplasty with split calvarial bone graft between 1982 and 2016 at the Cleveland Clinic were analyzed, recording demographics, comorbidities, indications, size and location of defect, and outcomes including complications and reoperations. Changes in graft thickness were analyzed using computed tomographic and magnetic resonance imaging scans. RESULTS: Forty-one patients with an average age of 33.2 years, cranial defect size of 68 cm, and mean follow-up of 28 months were included. The majority of patients (85 percent) had significant risk factors, with 43 percent suffering prior infection. Seventy-three percent of patients experienced successful restoration. A major complication was recorded in 26.8 percent; resorption occurred in 19.5 percent of patients (in 75 percent only at the recipient site), with 9.8 percent requiring reoperation. Patients with one or more risk factors or a smoking history were more likely to experience a complication. The mean ratio of the graft to the bicortical donor bone thickness was 0.48 ± 0.17 for the recipient site and 0.57 ± 0.10 for the donor site at an average radiographic follow-up of 11.9 ± 10.9 years. CONCLUSIONS: This study demonstrated a 73.2 percent first-attempt success rate in a high-risk population. The grafts maintain thickness over time, with no evidence of bone hypertrophy. Defect characteristics and patient systemic factors appear to be important variables influencing success. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Neuroendoscopic evacuation of intraventricular empyema using a side-cutting aspiration device.

Pyogenic ventriculitis is a rare but severe post-neurosurgical complication. The infection is often resistant to antibiotic treatment alone. Continuous intraventricular irrigation has been suggested but the technique is cumbersome, increases the risk for secondary infection, and is inadequate in removing adherent purulence. We used a novel neuroendoscopic approach assisted with a side-cutting aspiration device to treat four cases of post-neurosurgical pyogenic ventriculitis. Ventricular empyema was cleared in all patients and three of the four patients had favorable outcomes.

Management options of non-syndromic sagittal craniosynostosis.

There have been various effective surgical procedures for the treatment of non-syndromic sagittal craniosynostosis, but no definitive guidelines for management have been established. We conducted a study to elucidate the current state of practice and establish a warranted standard of care. An Internet-based study was sent to 180 pediatric neurosurgeons across the country and 102 craniofacial plastic surgeons in fourteen different countries, to collect data for primary indication for surgical management, preference for timing and choice of surgery, and pre-, peri-, and post-operative management options. The overall response rate from both groups was 32% (n=90/284). Skull deformity was the primary indication for surgical treatment in patients without signs of hydrocephalus for both neurosurgeons and craniofacial surgeons (80% and 63%, respectively). Open surgical management was most commonly performed at six months of age by neurosurgeons (46%) and also by craniofacial surgeons (35%). Open surgical approach was favored for patients younger than four months of age by neurosurgeons (50%), but endoscopic approach was favored by craniofacial surgeons (35%). When performing an open surgical intervention, most neurosurgeons preferred pi or reversed pi procedure (27%), whereas total cranial vault remodeling was the most commonly performed procedure by craniofacial surgeons (37%). The data demonstrated a discrepancy in the treatment options for non-syndromic sagittal craniosynostosis. By conducting/comparing a wide survey to collect consolidative data from both groups of pediatric neurosurgeons and craniofacial plastic surgeons, we can attempt to facilitate the establishment of standard of care.

Cortical herniation through compressive subdural membrane in an infant with a history of a large bihemispheric subdural hematoma and subdural-peritoneal shunt: case report.

Cortical herniation through subdural membrane formation is a rare complication of chronic subdural fluid collections and may occur following subdural shunting. The authors present a unique case of progressive cortical herniation through a compressive subdural membrane that occurred concomitant with a functioning subdural-peritoneal shunt.

Radiosurgery for Pediatric Brain Tumors.

The utility of radiosurgery for pediatric brain tumors is not well known. For children, radiosurgery may have an important role for treating unresectable tumors, residual disease, or tumors in the recurrent setting that have received prior radiotherapy. The available evidence demonstrates utility for some children with primary brain tumors resulting in good local control. Radiosurgery can be considered for limited residual disease or focal recurrences. However, the potential toxicities are unique and not insignificant. Therefore, prospective studies need to be performed to develop guidelines for indications and treatment for children and reduce toxicity in this population.

Lumbar spinal atypical teratoid rhabdoid tumor.

We describe a pediatric patient with an atypical teratoid rhabdoid tumor (AT/RT) exclusively of the lumbar spine, with a different presentation from the two previously reported pediatric lumbar AT/RT. AT/RT are rare pediatric tumors of the central nervous system, with a dismal prognosis. Although there is sufficient literature on brain AT/RT, spinal AT/RT continues to be a rare entity, with a lumbar location even less frequently reported. A 30-month-old African American boy with multiple comorbidities presented with the inability to ambulate, encopresis and urinary dribbling. The MRI showed an intradural extramedullary mass extending downwards from the L3-4 level. He underwent an L3-S2 laminoplasty. The surgically resected mass was marked by sheets of cells with large nuclei and prominent nucleoli. The tumor cells stained with antibodies to synaptophysin and CAM5.2, and showed no immunoreactivity to INI-1 antibody. He was diagnosed with a World Health Organization Grade IV AT/RT. There was no mutation detected in the SMARCB1 gene on a comprehensive analysis of his blood. The boy is currently being treated according to the Medical University of Vienna AT/RT protocol, with no evidence of tumor recurrence 8 months after surgery. To our knowledge, this is the only report of a lumbar AT/RT in an African American child.

Hyperosmolar and methotrexate therapy avoiding surgery in the acute presentation of primary central nervous system lymphoma.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is an aggressive type of extra-nodal non-Hodgkin lymphoma. Without treatment, PCNSL is associated with significant morbidity and mortality, including rapid neurological deterioration. In contrast to other high-grade intracranial neoplasms, PCNSL is considered to have a high response rate to conventional medical therapy, especially in younger patients, and therefore warrants particular attention in terms of nonsurgical treatment. CASE DESCRIPTION: We report a case of the medical management of acute deterioration due to rapidly growing PCNSL with mass effect to highlight the efficacy of temporization with hyperosmolar therapy while awaiting the known rapid effects of dexamethasone and methotrexate (MTX) treatment. Surgical intervention was avoided, and tumor response was rapid. The patient had corresponding clinical resolution of symptoms of elevated intracranial pressure with return to neurologic baseline. CONCLUSIONS: Despite the evidence that PCNSL responds well to steroids and MTX, the rapidity of onset with which this occurs can vary. In patients presenting with mass effect and rapid neurologic decline, there is little evidence to support medical over surgical intervention. Herein we present an illustrative case of a large PCNSL lesion presenting with rapid decline. With clinical improvement in one day and a 50% reduction in tumor volume over less than seven days, the authors present the specific time frame with which PCNSL responds to medical therapy and a safe strategy for medical temporization.

Prevention of percutaneous spinal cord stimulation electrode migration: a 15-year experience.

OBJECTIVES: Percutaneous spinal cord stimulation electrodes have a propensity to migrate longitudinally, which is a costly complication that often compromises therapeutic effect. After implementing simple changes to our percutaneous electrode anchoring technique, we no longer encounter this migration. The current retrospective study updates previously reported results. MATERIALS AND METHODS: We retrospectively examined data in a consecutive series of patients in whom we had secured a new percutaneous electrode by injecting < 0.1 cm(3) of adhesive into the silicone elastomer lead anchor. From 1998 through 2006, we used whichever anchor was supplied with each lead until we observed one case of migration through a short anchor; thereafter, we used a long, tapered anchor exclusively. From 2007 through 2013, we further modified our technique by adding a fascial incision to accommodate the tip of the anchor and by increasing the strength of our suture material. RESULTS: In the first series of 291 patients, followed through July 2007 (mean 4.75 years, range 1.1-9.0 years), 4 (1.37%) experienced electrode migration requiring surgical revision. Only one lead had moved with respect to its anchor; the other three anchors remained securely bonded to their leads. No migration (0.00%) occurred in the second series of 142 patients, followed through 2013 (mean follow-up 2.86 years, range 0.10-5.45 years). CONCLUSION: Improvements to our simple, inexpensive technique apparently have eliminated the most common complication of spinal cord stimulation.

Use of high-field intraoperative magnetic resonance imaging to enhance the extent of resection of enhancing and nonenhancing gliomas.

BACKGROUND: Intraoperative magnetic resonance imaging (IoMRI) is used to improve the extent of resection of brain tumors. Most previous studies evaluating the utility of IoMRI have focused on enhancing tumors. OBJECTIVE: To report our experience with the use of high-field IoMRI (1.5 T) for both enhancing and nonenhancing gliomas. METHODS: An institutional review board-approved retrospective review was performed of 102 consecutive glioma patients (104 surgeries, 2010-2012). Pre-, intra-, and postoperative tumor volumes were assessed. Analysis was performed with the use of volumetric T2 images in 43 nonenhancing and 13 minimally enhancing tumors and with postcontrast volumetric magnetization-prepared rapid gradient-echo images in 48 enhancing tumors. RESULTS: In 58 cases, preoperative imaging showed tumors likely to be amenable to complete resection. Intraoperative electrocorticography was performed in 32 surgeries, and 14 cases resulted in intended subtotal resection of tumors due to involvement of deep functional structures. No further resection (complete resection before IoMRI) was required in 25 surgeries, and IoMRI showed residual tumor in 79 patients. Of these, 25 surgeries did not proceed to further resection (9 due to electrocorticography findings, 14 due to tumor in deep functional areas, and 2 due to surgeon choice). Additional resection that was performed in 54 patients resulted in a final median residual tumor volume of 0.21 mL (0.6%). In 79 patients amenable to complete resection, the intraoperative median residual tumor volume for the T2 group was higher than for the magnetization-prepared rapid gradient-echo group (1.088 mL vs 0.437 mL; P = .049), whereas the postoperative median residual tumor volume was not statistically significantly different between groups. CONCLUSION: IoMRI enhances the extent of resection, particularly for nonenhancing gliomas.

Increased expression of glutamate transporter GLT-1 in peritumoral tissue associated with prolonged survival and decreases in tumor growth in a rat model of experimental malignant glioma.

OBJECT: Gliomas are known to release excessive amounts of glutamate, inducing glutamate excitotoxic cell death in the peritumoral region and allowing the tumor to grow and to expand. Glutamate transporter upregulation has been shown to be neuroprotective by removing extracellular glutamate in a number of preclinical animal models of neurodegenerative diseases, including amyotrophic lateral sclerosis and Parkinson disease as well as psychiatric disorders such as depression. The authors therefore hypothesized that the protective mechanism of glutamate transporter upregulation would be useful for the treatment of gliomas as well. METHODS: In this study 9L gliosarcoma cells were treated with a glutamate transporter upregulating agent, thiamphenicol, an antibiotic approved in Europe, which has been shown previously to increase glutamate transporter expression and has recently been validated in a human Phase I biomarker trial for glutamate transporter upregulation. Cells were monitored in vitro for glutamate transporter levels and cell proliferation. In vivo, rats were injected intracranially with 9L cells and were treated with increasing doses of thiamphenicol. Animals were monitored for survival. In addition, postmortem brain tissue was analyzed for tumor size, glutamate transporter levels, and neuron count. RESULTS: Thiamphenicol showed little effects on proliferation of 9L gliosarcoma cells in vitro and did not change glutamate transporter levels in these cells. However, when delivered locally in an experimental glioma model in rats, thiamphenicol dose dependently (10-5000 µM) significantly increased survival up to 7 days and concomitantly decreased tumor size from 46.2 mm(2) to 10.2 mm(2) when compared with lesions in nontreated controls. Furthermore, immunohistochemical and biochemical analysis of peritumoral tissue confirmed an 84% increase in levels of glutamate transporter protein and a 72% increase in the number of neuronal cells in the tissue adjacent to the tumor. CONCLUSIONS: These results show that increasing glutamate transporter expression in peritumoral tissue is neuroprotective. It suggests that glutamate transporter upregulation for the treatment of gliomas should be further investigated and potentially be part of a combination therapy with standard chemotherapeutic agents.

The periumbilical approach in ventriculoperitoneal shunt placement: technique and long-term results.

OBJECT: The aim of this study was to examine the feasibility and safety of ventriculoperitoneal (VP) shunt placement using a periumbilical approach for distal peritoneal access. By using this minimally invasive approach, the authors hypothesized that the cosmetic outcomes would be better than could be achieved by using a traditional minilaparotomy and that clinical results would be comparable. METHODS: A periumbilical approach was used for distal catheter insertion during a first-time VP shunt placement in 20 patients (8 males and 12 females). Median age at time of surgery was 3.0 months (range 7 days-11.9 years) and mean follow-up time was 17.8 months (range 1.2-28.0 months). The median weight of the patients was 3.99 kg (range 1.95-57.0 kg). A single incision was made along the natural crease inferior to the umbilicus. The linea alba was exposed and a 1-mm incision made while the patient was temporarily held in a Valsalva maneuver. A peritoneal trocar was then inserted through the fascial incision and the distal catheter was passed into the peritoneal space. RESULTS: The incision line in all patients healed well, did not require operative revision, and was described as minimally visible by the patients' families. Mean operative time was 35 minutes. Eight patients required revision surgery. One distal failure occurred when the distal shunt tubing retracted and became coiled in the neck; this was repaired by conversion to a minilaparotomy for distal replacement. There was 1 shunt infection (5%) requiring shunt removal and replacement. One patient had significant skin thinning around the valve and proximal catheter, which required replacement of the entire shunt system, and another patient underwent a conversion to a ventriculoatrial shunt due to poor peritoneal absorption. In the remaining 4 patients who required operative revision, the peritoneal portion of the shunt was not involved. CONCLUSIONS: The periumbilical approach for peritoneal access during VP shunt placement is technically feasible, has low infection rates, and has cosmetically appealing results. It may be considered as an alternative option to standard VP shunt placement techniques.

Ultrasonic BoneScalpel for osteoplastic laminoplasty in the resection of intradural spinal pathology: case series and technical note.

BACKGROUND: Osteoplastic laminoplasty is a well-described technique that may decrease the incidence of progressive kyphosis when used in the setting of intradural spinal cord tumor resection. OBJECTIVE: The BoneScalpel by Aesculap (Central Valley, Pennsylvania) is an ultrasonic osteotome that precisely cuts bone while preserving the underlying soft tissues, potentially reducing the risk of dural laceration during laminoplasty. By producing osteotomies as narrow as 0.5 mm, the device may also facilitate postoperative osteointegration. METHODS: A retrospective analysis was conducted of 40 patients (mean age, 38.0 years; range, 4.0-79.7 years) who underwent osteoplastic laminoplasty using the BoneScalpel for the treatment of intradural spinal pathology at the Johns Hopkins Hospital between January 2009 and December 2011. After lesion resection, titanium plates were used to reconstruct the lamina in all cases. The technical results and procedure-related complications were subsequently noted. RESULTS: Successful laminoplasty was carried out in all 40 patients. Intraoperatively, 1 case of incidental durotomy was noted after use of the device, which was repaired primarily without neurological or clinical sequelae. During the follow-up period (mean, 195 days; median, 144 days), there were 2 complications (1 cerebrospinal fluid leak, 1 seroma) and no cases of immediate postoperative instability. CONCLUSION: The BoneScalpel is a safe and technically feasible device for performing osteoplastic laminoplasty.

Combination of paclitaxel thermal gel depot with temozolomide and radiotherapy significantly prolongs survival in an experimental rodent glioma model.

OncoGel™ incorporates paclitaxel, a mitotic inhibitor, into ReGel™, a thermosensitive gel depot system to provide local delivery, enhance efficacy and limit systemic toxicity. In previous studies the alkylating agent temozolomide (TMZ) incorporated into a polymer, pCPP:SA, also for local delivery, and OncoGel were individually shown to increase efficacy in a rat glioma model. We investigated the effects of OncoGel with oral TMZ or locally delivered TMZ polymer, with and without radiotherapy (XRT) in rats with intracranial gliosarcoma. Eighty-nine animals were intracranially implanted with a 9L gliosarcoma tumor and divided into 12 groups that received various combinations of 4 treatment options; OncoGel 6.3 mg/ml (Day 0), 20 Gy XRT (Day 5), 50 % TMZ-pCPP:SA (Day 5), or oral TMZ (50 mg/kg, qd, Days 5-9). Animals were followed for survival for 120 days. Median survival for untreated controls, XRT alone or oral TMZ alone was 15, 19 and 28 days, respectively. OncoGel 6.3 or TMZ polymer alone extended median survival to 33 and 35 days, respectively (p = 0.0005; p < 0.0001, vs. untreated controls) with 50 % living greater than 120 days (LTS) in both groups. Oral TMZ/XRT extended median survival to 36 days (p = 0.0002), with no LTS. The group that received OncoGel and Oral TMZ did not reach median survival with 57 % LTS (p = 0.0002). All other combination groups [OncoGel/XRT], [TMZ polymer/XRT], [OncoGel/TMZ polymer], [OncoGel/TMZ polymer/XRT], and [OncoGel/oral TMZ/XRT] yielded greater than 50 % LTS (p < 0.0001 for each combination as compared to controls), therefore median survival was not reached. OncoGel/TMZ polymer and OncoGel/oral TMZ/XRT had 100 % LTS (p < 0.0001 and p = 0.0001 vs. oral TMZ/XRT, respectively). These results indicate that OncoGel given locally with oral or locally delivered TMZ and/or XRT significantly increased the number of LTS and improved median survival compared to oral TMZ and XRT given alone or in combination in a rodent intracranial gliosarcoma model.

Surgical briefings, checklists, and the creation of an environment of safety in the neurosurgical intraoperative magnetic resonance imaging suite.

Technological advances have made it possible to seamlessly integrate modern neuroimaging into the neurosurgical operative environment. This integration has introduced many new applications improving surgical treatments. One major addition to the neurosurgical armamentarium is intraoperative navigation and MRI, enabling real-time use during surgery. In the 1970s, the American College of Radiology issued safety guidelines for diagnostic MRI facilities. Until now, however, no such guidelines existed for the MRI-integrated operating room, which is a high-risk zone requiring standardized protocols to ensure the safety of both the patient and the operating room staff. The forces associated with the strong 1.5- and 3.0-T magnets used for MRI are potent and hazardous, creating distinct concerns regarding safety, infection control, and image interpretation. Authors of this paper provide an overview of the intraoperative MRI operating room, safety considerations, and a series of checklists and protocols for maintaining safety in this zero tolerance environment.

Poland syndrome with extracorporeal intercostal liver herniation and thoracic myelomeningocele.

Poland syndrome is characterized by hypoplastic unilateral chest wall structures. These chest wall deformities may be associated with upper extremity anomalies. The association of Poland syndrome with either intercostal liver herniation or a spinocerebral deformity has been described, but there is no report of both findings encountered simultaneously. This is the first report of a newborn child with Poland syndrome associated with an intercostal liver segment herniation and thoracic myelomeningocele with features of an Arnold-Chiari II cerebral malformation.

Vein of Galen malformations: epidemiology, clinical presentations, management.

The vein of Galen aneurysmal malformation is a congenital vascular malformation that comprises 30% of the pediatric vascular and 1% of all pediatric congenital anomalies. Treatment is dependent on the timing of presentation and clinical manifestations. With the development of endovascular techniques, treatment paradigms have changed and clinical outcomes have significantly improved. In this article, the developmental embryology, clinical features and pathophysiology, diagnostic workup, and management strategies are reviewed.