3D printed headholder for use in neurosurgical cadaver training: Technical note.

Introduction: Headholders or skull clamps serve as indispensable tools in neurosurgery, facilitating the precise positioning and stabilization of the head for surgery. The realm of neurosurgical training in cadaver labs presents a clear challenge due to the lack of suitable non-clinical headholders. Research question: We describe a 3D printed stainless-steel headholder for use in neurosurgical cadaver lab training. Material and methods: Computer-aided design software was used to design a headholder, utilizing a three-pin skull fixation. Through an iterative process involving a plastic 3D printed prototype, ultimately a robust model was manufactured using a 3D stainless-steel printer. Results: The headholder was fixed to a multi-angle adjustable vise, enabling optimal positioning to support simulation of neurosurgical approaches and dissection training by neurosurgical residents and staff in the cadaver lab. Discussion and conclusion: This custom-made headholder offers an effective solution for secure fixation of cadaver skulls during neurosurgical training, contributing to practicality and efficiency in cadaver dissection. Despite the lack of evidence-based guidelines for neurosurgical headholder use, this device provides a valuable tool for neurosurgical trainees to practice proper placement, understand associated complications, and improve their hands-on skills. The digitally available 3D model can be optimized, shared, and further improved by other neurosurgical units and trainees, fostering collaborative advancements in neurosurgical training.

Computer-Aided-Design/Computer-Aided-Manufacturing Titanium Cranioplasty in a Child: Critical Appraisal.

Large skull bone defects of the cranial vault can result from various reasons. Reconstruction of these defects is performed for protective and aesthetic reasons but is also required for adequate intracranial homeostasis. Computer-aided-design/computer-aided-manufacturing (CAD/CAM) patient-specific skull implants have become the most valuable alternative to the traditional methods of reconstruction and a growing number of publications is dealing with this topic in adults. Literature related to the application of these implants in pediatric cranioplasty is, however, still scarce.The authors present a case of a 9-year-old boy, where cranioplasty using a CAD/CAM additive manufactured titanium implant led to improvement of symptoms attributed to cerebrospinal fluid circulation problems and intracranial homeostasis disbalance. The authors further reflect on what the role of cranioplasty should be in the therapeutic treatment plan.

Cranioplasty with patient-specific implants in repeatedly reconstructed cases.

OBJECTIVE: Cranioplasty is indicated to restore form and function of bone defects of the neurocranium. Autografts are the gold standard, alloplastic materials are used when autologous bone is unavailable or unsuitable, and increasing evidence supports the use of patient-specific implants (PSIs) for reconstruction. We reviewed our own patient data to assess pre- and intraoperative aspects, complications and costs in patients that were treated with PSIs from titanium or polyetheretherketone (PEEK) for skull bone reconstruction. METHODS: We retrospectively evaluated all patients receiving a PSI as at least a secondary reconstruction between 2004 and 2016 at Maastricht University Medical Center. These cases were analyzed for demographics, perioperative surgical and medical aspects, as well as costs. RESULTS: In total 30 patients received PSIs, of which 20 were included in this study. Duration of PSI placement was not statistically different between group I, where previously placed reconstruction material was still in situ, and group II, where no remaining previously placed reconstruction material was present (group I: 104 ± 27 mins, group II: 86 ± 36 mins; p = 0.27). Postoperatively, 2 patients experienced complications (10%). Costs of obtaining the PSIs were not significantly different between group I and group II (group I: mean EUR 7536 ± 2759, group II: mean EUR 8351 ± 2087, p = 0.51). CONCLUSION: Treatment of skull bone defects in repeated reconstruction requires an optimal preoperative planning and intraoperative procedure. In this retrospective study comparing repeatedly reconstructed cases with and without remaining previously placed reconstruction material present at the surgical site, we could not find significant differences in the duration of the surgical procedure nor costs of obtaining the PSIs. The protocol followed at MUMC for preoperative planning, manufacturing, and surgery, represents the current state-of-the-art treatment.

The therapeutic effect of patient-specific implants in cranioplasty.

OBJECTIVE: Patient specific implants have been used for the reconstruction of large skull bone defects. Several therapeutic effects have been suggested in current literature but were never objectified. The aim of the current study was to evaluate the change in quality of life, pain, aesthetics, and the surgical and medical outcomes after reconstruction of large skull bone defects with titanium or polyetheretherketone (PEEK) implants. METHODS: We retrospectively evaluated 29 consecutive patients receiving a patient specific skull implant between November 2004 and December 2015. Twenty-one patients received PEEK implants and eight received titanium implants. Data was acquired regarding quality of life, aesthetics, pain, demographics and complications. Quality of life was measured using the Glasgow Benefit Inventory (GBI). Additional questions were asked concerning pain, satisfaction and aesthetics. RESULTS: The mean total GBI-score was +26.1 (95%CI 16.8-35.4, p < 0.001). Headache complaints or pain in the operation site improved in 75.0% and 77.8% of these patients, respectively. In 8.0% an increase was seen with regard to both variables. CONCLUSION: Reconstruction of skull bone defects with PEEK and titanium patient specific implants gave a statistically significant improvement in quality of life. Furthermore, it decreased pain and headaches and gave aesthetically good results.

Intraoperative magnetic resonance imaging versus standard neuronavigation for the neurosurgical treatment of glioblastoma: A randomized controlled trial.

BACKGROUND: Although the added value of increasing extent of glioblastoma resection is still debated, multiple technologies can assist neurosurgeons in attempting to achieve this goal. Intraoperative magnetic resonance imaging (iMRI) might be helpful in this context, but to date only one randomized trial exists. METHODS: We included 14 adults with a supratentorial tumor suspect for glioblastoma and an indication for gross total resection in this randomized controlled trial of which the interim analysis is presented here. Participants were assigned to either ultra-low-field strength iMRI-guided surgery (0.15 Tesla) or to conventional neuronavigation-guided surgery (cNN). Primary endpoint was residual tumor volume (RTV) percentage. Secondary endpoints were clinical performance, health-related quality of life (HRQOL) and survival. RESULTS: Median RTV in the cNN group is 6.5% with an interquartile range of 2.5-14.75%. Median RTV in the iMRI group is 13% with an interquartile range of 3.75-27.75%. A Mann-Whitney test showed no statistically significant difference between these groups (P =0.28). Median survival in the cNN group is 472 days, with an interquartile range of 244-619 days. Median survival in the iMRI group is 396 days, with an interquartile range of 191-599 days (P =0.81). Clinical performance did not differ either. For HRQOL only descriptive statistics were applied due to a limited sample size. CONCLUSION: This interim analysis of a randomized trial on iMRI-guided glioblastoma resection compared with cNN-guided glioblastoma resection does not show an advantage with respect to extent of resection, clinical performance, and survival for the iMRI group. Ultra-low-field strength iMRI does not seem to be cost-effective compared with cNN, although the lack of a valid endpoint for neurosurgical studies evaluating extent of glioblastoma resection is a limitation of our study and previous volumetry-based studies on this topic.

Cranioplasty with customized titanium and PEEK implants in a mechanical stress model.

Large skull defects as a result of craniectomies due to cerebral insults, trauma, or tumors create functional and aesthetic disturbances for the patient. Cranioplasty with implants in these cases are an alternative to autogenous bone transplantation. In our clinic, customized titanium or optima poly-ether-ether ketone (PEEK) implants are used to reconstruct craniectomy defects. To compare the two materials we investigated the structural changes of the implants fixed to a sintered polyamide skull model under mechanical stress in four simplified models. In a standard testing machine, the models were subjected to a load under a quasi-static loading rate of 1.925 mm/min. Fractures of the PEEK implants occurred at a force of 24.2 and 24.5 kN with a displacement of 8.4 and 8 mm. The titanium implants showed no deformation, but extensive damage was seen in the polyamide skull models. The highest pressures achieved were 45.8 and 50.9 kN. In a simplified model with quasi-static loading, both implants withstood forces that were higher than those capable of causing skull fractures. It seems that the mechanical properties of PEEK could provide better protection when used for cranioplasty in patients after craniectomy if reconstruction with autogenous bone is not possible.

Correlation between contrast enhancement on intraoperative magnetic resonance imaging and histopathology in glioblastoma.

OBJECT: Glioblastoma is a highly malignant brain tumor, for which standard treatment consists of surgery, radiotherapy, and chemotherapy. Increasing extent of tumor resection (EOTR) is associated with prolonged survival. Intraoperative magnetic resonance imaging (iMRI) is used to increase EOTR, based on contrast enhanced MR images. The correlation between intraoperative contrast enhancement and tumor has not been studied systematically. METHODS: For this prospective cohort study, we recruited 10 patients with a supratentorial brain tumor suspect for a glioblastoma. After initial resection, a 0.15 Tesla iMRI scan was made and neuronavigation-guided biopsies were taken from the border of the resection cavity. Scores for gadolinium-based contrast enhancement on iMRI and for tissue characteristics in histological slides of the biopsies were used to calculate correlations (expressed in Kendall's tau). RESULTS: A total of 39 biopsy samples was available for further analysis. Contrast enhancement was significantly correlated with World Health Organization (WHO) grade (tau 0.50), vascular changes (tau 0.53), necrosis (tau 0.49), and increased cellularity (tau 0.26). Specificity of enhancement patterns scored as "thick linear" and "tumor-like" for detection of (high grade) tumor was 1, but decreased to circa 0.75 if "thin linear" enhancement was included. Sensitivity for both enhancement patterns varied around 0.39-0.48 and 0.61-0.70, respectively. CONCLUSIONS: Presence of intraoperative contrast enhancement is a good predictor for presence of tumor, but absence of contrast enhancement is a bad predictor for absence of tumor. The use of gadolinium-based contrast enhancement on iMRI to maximize glioblastoma resection should be evaluated against other methods to increase resection, like new contrast agents, other imaging modalities, and "functional neurooncology" - an approach to achieve surgical resection guided by functional rather than oncological-anatomical boundaries.

Intraoperative MRI-guided resection of glioblastoma multiforme: a systematic review.

We did a systematic review to address the added value of intraoperative MRI (iMRI)-guided resection of glioblastoma multiforme compared with conventional neuronavigation-guided resection, with respect to extent of tumour resection (EOTR), quality of life, and survival. 12 non-randomised cohort studies matched all selection criteria and were used for qualitative synthesis. Most of the studies included descriptive statistics of patient populations of mixed pathology, and iMRI systems of varying field strengths between 0·15 and 1·5 Tesla. Most studies provided information on EOTR, but did not always mention how iMRI affected the surgical strategy. Only a few studies included information on quality of life or survival for subpopulations with glioblastoma multiforme or high-grade glioma. Several limitations and sources of bias were apparent, which affected the conclusions drawn and might have led to overestimation of the added value of iMRI-guided surgery for resection of glioblastoma multiforme. Based on the available literature, there is, at best, level 2 evidence that iMRI-guided surgery is more effective than conventional neuronavigation-guided surgery in increasing EOTR, enhancing quality of life, or prolonging survival after resection of glioblastoma multiforme.

Intramedullary cavernoma presenting with hematomyelia: report of two girls.

INTRODUCTION: Less than 20 children with intramedullary cavernoma (ImC) have been reported in the English literature; however, cases with an unfavorable outcome may be underreported. Whereas these are predominantly boys, we report two girls who presented with hematomyelia (one cervical, one thoracic) and an acute, severe neurological deficit. CASE MATERIAL: A 10-year-old girl complaining about lower thoracic pain for several days suddenly developed lower body dysesthesias and paraparesis. Magnetic resonance (MR) demonstrated hematomyelia (T8-T11), intramedullary edema (T6-L1), and an ImC at T9-T10. Within an hour, she progressed to paraplegia and was therefore operated immediately. She slowly recovered regaining independent ambulation and continence. MR after 2 years shows no recurrence. A 7-year-old girl suddenly developed cervicalgia and paresis of her left arm and leg. MR demonstrated hematomyelia and an ImC at C4-C6. She gradually recovered with minimal residual deficit at 3 months and was subsequently operated uneventfully. Multiple cerebral cavernomas and a familial autosomal cavernous malformation syndrome were diagnosed. The following 1.5 years, she complained of intermittent cervicalgia and left brachial dysesthesias, with MR suggesting active residual cavernoma. Interestingly, her complaints gradually disappeared, and she is currently asymptomatic. MR after 3.5 years shows minimal cord swelling no longer suggesting active residual cavernoma. CONCLUSION: With adequate surgical treatment either in the acute phase in case of dramatic deterioration or after clinical recuperation, prognosis of symptomatic ImC may be surprisingly good. However, subtotally resected lesions and/or syndromal cases may recur, requiring further treatment. Definitive answers await more cases with longer follow-up.

Solitary juvenile xanthogranuloma of the temporal muscle and bone penetrating the dura mater in a 2-month-old boy.

Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder primarily observed during the first 2 years of life. Most patients present with a solitary cutaneous lesion; however, others present with extracutaneous manifestations or even with systemic involvement. The authors describe a 2-month-old boy in whom was diagnosed a unifocal extracutaneous JXG involving the temporal bone. Unlike 3 other cases of solitary JXGs of the temporal bone in the literature, the present case involved destruction of the dura mater and leptomeningeal enhancement surrounding the entire temporal lobe. The lesion did not regress after an initial biopsy procedure and had to be removed more radically because of progressive mass effect on the brain. The child recently underwent a reconstructive skull procedure and is doing well almost 2 years postoperatively without evidence of disease. This case demonstrates that even in instances of extensive disease a favorable outcome is possible without chemotherapy.

Two brothers with a symptomatic thoracic disc herniation at T11-T12: clinical report.

BACKGROUND: In contrast to what is commonly believed, thoracic disc herniations are not rare lesions. Their etiopathogenesis is largely unknown, but may be linked to trauma, Scheuermann's disease or a degenerative back. OBJECTIVE: We report two brothers with a symptomatic thoracic disc herniation at T11-T12 and address the possibility of a genetic factor as well as other factors in the etiopathogenesis of (symptomatic) thoracic disc herniations. CLINICAL FEATURES: Both brothers were in their early thirties and had a physically demanding job, however, only the first one was a smoker and was diagnosed with Scheuermann's disease. CONCLUSION: The etiology of thoracic disc herniations is likely multifactorial. Their occurrence in siblings may reflect some genetic predisposition or may be merely coincidental, given the high prevalence of thoracic disc herniations in asymptomatic individuals. Further research, including genetic studies, is warranted.