Intracerebral laser interstitial thermal therapy followed by tumor resection to minimize cerebral edema.

OBJECTIVE Laser interstitial thermal therapy (LITT) is used in numerous neurosurgical applications including lesions that are difficult to resect. Its rising popularity can be attributed to its minimally invasive approach, improved accuracy with real-time MRI guidance and thermography, and enhanced control of the laser. One of its drawbacks is the possible development of significant edema, which contributes to extended hospital stays and often necessitates hyperosmolar or steroid therapy. Here, the authors discuss the use of minimally invasive craniotomy to resect tissue ablated with LITT in attempt to minimize cerebral edema. METHODS Five patients with glioblastoma multiforme prospectively underwent LITT followed by resection. The LITT was performed with the aid of an MR-compatible skull-mounted frame in the MRI suite. Ablated tumor was then resected via small craniotomy by using the NICO Myriad system or cavitron ultrasonic surgical aspirator. Postoperative management involved dexamethasone administration slowly tapered over several weeks. RESULTS The use of resection following LITT, as compared with open resection or LITT alone, did not extend the hospital stay except in 1 patient who required 3-day inpatient management of edema with a trapped ventricle. No new neurological deficits were encountered, although 1 patient developed seizures postoperatively. No increase in infection rates was identified. CONCLUSIONS Resection of ablated tumor is a viable option to reduce the incidence of neurological deficits due to edema following LITT. This approach appears to mitigate cerebral edema by increasing available volume for mass effect and reducing the tissue burden that may promote an inflammatory response.

Virtual Interviews During COVID-19 Changed Neurosurgery Match-for Better or Worse.

OBJECTIVE: The COVID-19 pandemic forced neurosurgery residency application processes to adopt a virtual interview model. This study analyzes the trends in program and applicant residency match behavior due to virtual interviews. METHODS: National Resident Matching Program data from Main Residency Match, National Resident Matching Program Director and Applicant Survey, Electronic Residency Application Service, and Charting Outcomes in the Match were collected for neurosurgery residents for all available years, providing information on neurosurgery residency application, interview, and match outcomes. Studied years were dichotomized to account for virtual versus in-person interviews and analyzed for differences. RESULTS: Although the average number of applications received during in-person versus virtual years was not statistically different, 245 versus 290 (P = 0.115), programs interviewed more applicants when interviews were virtual, 37.2 versus 46, (P = 0.008). Similarly, matched U.S. senior applicants did not submit a statistically higher number of applications in person versus virtual, 54 versus 77 (P = 0.055), but they did attend more interviews virtually, 20.5 versus 16.6 (P = 0.013), and ranked more programs, 20 versus 16.2 (P = 0.002). Although White applicants did not have a statistically significant difference in number of applications submitted (55 vs. 68, P = 0.129), Black applicants submitted more applications during virtual match compared with in-person match (52 vs. 74, P = 0.012). The number of applicants that programs needed to rank to fill each position was not statistically different when comparing in-person versus virtually conducted interviews, 4.6 versus 5.4 (P = 0.070). CONCLUSIONS: Despite no change in the overall number of applications submitted per applicant, Black applicants submitted more applications virtually, suggesting potential benefits of virtual format for Black applicants. Interview format was strongly correlated to the use of perceived fitness by applicants in rank decision making. Virtual interviews provide major financial advantages to candidates and could help improve Black representation in neurosurgery. However, they impose limitations on ability access fitness.

Clear neuroimaging margin at the brain-tumor interface is associated with gross total resection and longer survival in non-enhancing diffuse gliomas.

BACKGROUND: This study aimed to determine whether the presence of distinct glioma margins on preoperative imaging is correlated with improved intraoperative identification of tumor-brain interfaces and overall improved surgical outcomes of non-enhancing gliomas. METHODS: This is a retrospective study of all primary glioma resections at our institution between 2000-2020. Tumors with contrast enhancement or with final pathology other than diffuse infiltrative glial neoplasm (WHO II or WHO III) were excluded. Tumors were stratified into two groups: those with distinct radiographical borders between tumor and brain, and those with ill-defined radiographical margins. Multivariate analysis was performed to determine the impact of clear preoperative margins on the primary outcome of gross-total resection. RESULTS: Within the study period, 59 patients met inclusion criteria, of which 31 (53%) had distinct margins. These patients were predominantly younger (37.6 vs. 48.1 years, P=0.007). Tumor and other patient characteristics were similar in both cohorts, including gender, laterality, size, location, tumor type, grade, and surgical adjuncts utilized (P>0.05). Multivariate regression identified that distinct preoperative margins correlated with increased rates of gross total resection (P=0.02). Distinct margins on preoperative neuroimaging also correlated positively with surgeon identification of intra-operative margins (P<0.0001), fewer deaths over the study period (P=0.01), and longer overall survival (P=0.03). CONCLUSIONS: Distinct glioma-parenchyma margins on preoperative imaging are associated with improved surgical resection for diffuse gliomas, as distinct margins may correlate with distinguishable glioma-brain interfaces intraoperatively. Further prospective studies may discover additional clinical uses for these findings.

Fusiform dilatation of the cavernous carotid artery in acromegalic patients.

BACKGROUND: Surgeons undertaking transsphenoidal surgery in patients with acromegaly confront multiple unique challenges secondary to the anatomic alterations caused by growth hormone-secreting tumors. The senior author has noted a fusiform dilatation of the cavernous carotid artery in many acromegalic patients. The authors aim to quantify this dilatation and correlate it with potential contributing factors. METHODS: Clinical and radiographic data were retrospectively assessed in acromegalic patients undergoing transsphenoidal surgery from 2000 through 2011. Randomly selected patients with nonsecreting pituitary adenomas were used as the control cohort. Demographic information, comorbidities, and preoperative growth hormone and insulin-like growth factor-1 levels were recorded. Magnetic resonance (MR) imaging variables included tumor size, diameters of the petrous, cavernous, and supraclinoid segments of the carotid artery, and extent and location of cavernous sinus invasion. Independent correlations between acromegaly and each variable were assessed with multivariate regression analysis. RESULTS: Forty randomly selected patients with growth hormone-secreting adenomas who underwent surgery and had MR imaging with thin coronal slices of the pituitary region were enlisted in our study cohort. The mean age was 45.7 years. Forty-two males (52.5 %) were included in the study. Mean carotid artery diameter measurements for acromegalic and control patients, respectively, were 4.2 vs. 3.8 mm (petrous carotid), 5.0 vs. 4.0 mm (cavernous carotid), and 3.3 vs. 2.9 mm (supraclinoid carotid). Multivariate analysis showed only age and cavernous carotid diameter were statistically significant independent variables (p = 0.02, p < 0.001, respectively). Age, tumor size, growth-hormone or insulin-like growth factor-1 levels, and cavernous sinus invasion did not correlate with cavernous carotid artery diameter. CONCLUSIONS: In patients with acromegaly, there is a fusiform dilatation of the cavernous carotid artery that must be considered when planning transsphenoidal surgery.

Neurosurgery Resident Attrition Rates Defy Trends and Decrease During COVID-19 Pandemic.

OBJECTIVE: We sought to determine the effects of the coronavirus disease 2019 (COVID-19) pandemic on U.S. neurosurgery resident attrition. We report the changes in resident attrition due to transfers, withdrawal, or dismissal from program training during the COVID-19 pandemic. METHODS: Neurosurgery resident attrition data reported by the American Council of Graduate Medical Education for the academic year starting in July 2007 to the academic year ending in June 2022 were collected, and the rate of attrition was calculated. Individual postgraduate year program transfer rates were also calculated for the previous 7 consecutive academic years. The attrition rates for the academic years before the pandemic were compared with those during the pandemic. RESULTS: A total of 465 residents did not graduate from neurosurgical training during the past 15 academic years, of which 3 years were at least partially during the COVID-19 pandemic, resulting in a mean attrition rate of 2.5%. The attrition rates during the pandemic were lower than those before the pandemic (1.7% vs. 2.7%; P < 0.001), driven largely by a nearly twofold decrease in the withdrawal rate (0.67% vs. 1.2%; P = 0.003). Bivariate regression between the withdrawal and attrition rates showed a statistically significant correlation (r = 0.809; P < 0.001; r2 = 0.654). The first full year of the COVID-19 pandemic saw the most dramatic changes, with a z score for attrition of -1.9. Linear regression of the effect of training during the COVID-19 pandemic on attrition revealed a statistically significant difference (r = 0.563; P = 0.029; r2 = 0.317). The rate of withdrawal was most affected by training during the pandemic (r = 0.594; P = 0.010; r2 = 0.353). CONCLUSIONS: A statistically significant decline occurred in the rate of neurosurgery resident attrition during the COVID-19 pandemic that was most notable during the first full academic year (2020-2021). These findings were largely driven by a decrease in residents withdrawing from training programs. This contrasts with the overall trend toward resignation among healthcare workers during the pandemic. It is unclear what enduring ramifications this will have on neurosurgery residencies moving forward and whether we will see higher attrition rates as we transition toward a new normal. Future studies should examine trends in the attrition rates after the COVID-19 pandemic and determine the long-term effects of decreased attrition rates of residents during the pandemic.

Analysis of Imaging Results for Semisitting Compared with Supine Positioning in the Retrosigmoid Approach for Resection of Cerebellopontine Angle Vestibular Schwannomas.

OBJECTIVE: To compare the completeness of resection of vestibular schwannomas using three-dimensional segmented volumetric analysis of pre- and postoperative magnetic resonance imaging (MRI) of patients undergoing supine and semisitting positioning for the retrosigmoid approach. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary medical center. PATIENTS: Patients with vestibular schwannomas undergoing surgical resection via the retrosigmoid approach. INTERVENTIONS: Tumor resection via the retrosigmoid approach with different patient positioning: standard supine versus semisitting. MAIN OUTCOME MEASURES: Preoperative versus postoperative three-dimensional segmented volumetric MRI analysis of vestibular schwannomas. RESULTS: A total of 43 patients (15 supine and 28 semisitting) underwent retrosigmoid craniotomy for resection of vestibular schwannomas. For the conventional supine and semisitting positioning, mean preoperative tumor volumes were 12.65 and 8.73 cm 3 ( p = 0.15), respectively. Postoperative mean tumor volumes for the supine and semisitting positions were 2.09 and 0.48 cm 3 ( p = 0.13), respectively. There were 11 cases of postoperative sigmoid sinus thrombosis, 3 in the conventional supine group and 8 in the semisitting groups, and there were 6 cases of postoperative cerebrospinal fluid leaks, all in the semisitting group. The mean House-Brackmann scores for the supine and semisitting groups were 2.9 and 2.3, respectively. There was no statistically significant difference between groups in the rates of these or any other postoperative complications. CONCLUSIONS: The semisitting position for the suboccipital retrosigmoid approach for vestibular schwannoma resection does not compromise the ability to adequately resect the tumor as seen by volumetric MRI results. Further studies are needed to establish the safety of this position compared with the traditional supine approach.

Evaluating Match and Attrition Rates for Women and African Americans in Neurosurgery.

BACKGROUND: Previous efforts to increase diversity in neurosurgery have been aimed primarily at female inclusion while little analysis of other under-represented groups has been performed. OBJECTIVE: To evaluate match and retention rates of under-represented groups in neurosurgery, specifically Black and female applicants compared with non-Black and male applicants. METHODS: Match lists, Electronic Residency Application Service data, and National Resident Matching Program data were retrospectively reviewed along with publicly available residency program information for successful matriculants from 2017 to 2020. Residents were classified into demographic groups, and analysis of match and retention rates was performed. RESULTS: For 1780 applicants from 2017 to 2020, 439 identified as female while 1341 identified as male. Of these 1780 applicants, 128 identified as Black and 1652 identified as non-Black. Male and female applicants matched at similar rates ( P = .76). Black applicants matched at a lower rate than non-Black applicants ( P < .001). From 2017 to 2020, neither race nor sex was associated with retention as 94.1% of male applicants and 93.2% of female applicants were retained ( P = .63). In total, 95.2% of Black residents and 93.9% of non-Black residents were retained ( P = .71). No intraregional or inter-regional differences in retention were found for any group. CONCLUSION: Although sex parity has improved, Black applicants match at lower rates than non-Black applicants but are retained after matriculation at similar rates. Neurosurgery continues to recruit fewer female applicants than male applicants. More work is needed to extend diversity to recruit under-represented applicants. Future studies should target yearly follow-up of retention and match rates to provide trends as a measure of diversification progress within the field.

Outcomes and Utility of Intracranial Free Tissue Transfer.

OBJECTIVE: Complications associated with intracranial vault compromise can be neurologically and systemically devastating. Primary and secondary repair of these deficits require an air and watertight barrier between the intracranial and extracranial environments. This study evaluated the outcomes and utility of using intracranial free tissue transfer as both primary and salvage surgical repair of reconstruction. METHODS: A retrospective review was performed of all subjects who underwent intracranial free tissue transfer as primary or salvage repair. RESULTS: A total of 13 intracranial free tissue transfers were performed on 11 subjects: osteocutaneous radial forearm free flaps (n = 6), partial myofascial rectus abdominis flaps (n = 5), temporoparietal fascia flap (n = 1), and serratus anterior myofascial flap (n = 1). Primary reconstruction was performed on 4 subjects with the remaining being salvage repair. Indications for surgery included neoplasm (n = 6 of 11), ballistic trauma (n = 3 of 11), motor vehicle accident (n = 1 of 11), and infection (n = 1 of 11). Three subjects required additional surgical repair for CSF leak and pneumocephalus, with 2 subjects requiring an additional free tissue transfer at a different site. CONCLUSION: In our experience, free tissue transfer is an effective primary and salvage surgical technique in the reconstruction of complex intracranial problems.

Malignant rhabdoid tumor of the spine in an infant: case report and review of the literature.

Malignant rhabdoid tumors of the spine are rare pediatric neoplasms that have a poor prognosis. The histological, ultrastructural, and immunohistochemical features are essential elements used in their diagnosis. We report the case of a malignant rhabdoid tumor of the cervical spine in a 13-month-old infant. Tumor cells were vimentin positive with prominent nucleoli indented by eosinophilic cytoplasmic inclusions containing intermediate filaments. INI1 immunostaining was negative. This patient was operated on twice for symptomatic spinal cord compression. Despite chemotherapy, she developed worsening leptomeningeal dissemination, lower cranial nerve dysfunction, and hydrocephalus that did not respond to CSF diversion. She died 4 months after initial diagnosis. We review the literature on spinal malignant rhabdoid tumor and discuss the nomenclature, pathology, radiology, treatment, and outcomes of this rare entity.

Primary disseminated intradural malignant peripheral nerve sheath tumor of the spine in a child: case report and review of the literature.

The authors report a rare case of primary disseminated intradural malignant peripheral nerve sheath tumor (MPNST) of the spine in a 5-year-old child without neurofibromatosis type I (NF-I). This child presented with abdominal pain and gait disturbance. MRI revealed a large intradural extramedullary tumor at C4-5 with dissemination to the thoracic spine, cauda equina and leptomeninges. Following a 2-level cervical laminectomy, the tumor was biopsied and debulked. Based on pathological and immunohistological findings, the tumor was diagnosed as an MPNST. Because of the rarity of this pathological entity, a review of the literature was performed. The reported clinical outcomes for adult and pediatric patients with intradural MPNST are very poor. No established standard for the treatment of these tumors exists. We report the first pediatric case--without or with NF-I--of disseminated intradural MPNST primarily localized proximal to the conus medullaris. It must always be considered in the differential diagnosis for intradural extramedullary tumors of the pediatric spine, along with neurofibromas and schwannomas, even in children without NF-I.

Neuronavigation applied to epilepsy monitoring with subdural electrodes.

Accurate localization of the epileptogenic zone is of paramount importance in epilepsy surgery. Despite the availability of noninvasive structural and functional neuroimaging techniques, invasive monitoring with subdural electrodes is still often indicated in the management of intractable epilepsy. Neuronavigation is widely used to enhance the accuracy of subdural grid placement. It allows accurate implantation of the subdural electrodes based on hypotheses formed as a result of the presurgical workup, and can serve as a helpful tool for resection of the epileptic focus at the time of grid explantation. The authors describe 2 additional simple and practical techniques that extend the usefulness of neuronavigation in patients with epilepsy undergoing monitoring with subdural electrodes. One technique involves using the neuronavigation workstation to merge preimplantation MR images with a postimplantation CT scan to create useful images for accurate localization of electrode locations after implantation. A second technique involves 4 holes drilled at the margins of the craniotomy at the time of grid implantation; these are used as fiducial markers to realign the navigation system to the original registration and allow navigation with the merged image sets at the time of reoperation for grid removal and resection of the epileptic focus. These techniques use widely available commercial navigation systems and do not require additional devices, software, or computer skills. The pitfalls and advantages of these techniques compared to alternatives are discussed.

Neuroendoscopic fenestration of glioependymal cysts to the ventricle: report of 3 cases.

Glioependymal cysts are rare congenital lesions of the central nervous system. Reported surgical treatments of these lesions have varied and yielded mixed results, and the optimal surgical strategy is still controversial. The authors here report the clinical and surgical outcomes for three adult patients successfully treated with neuroendoscopic fenestration into the ventricular system. The patients had presented with symptomatic glioependymal cysts in the period from 2013 to 2016 at the authors' institution. All underwent minimally invasive neuroendoscopic fenestration of the glioependymal cyst into the lateral ventricle via a stereotactically guided burr hole. Presenting clinical and radiological findings, operative courses, and postintervention outcomes were evaluated.All three patients initially presented with symptoms related to regional mass effect of the underlying glioependymal cyst, including headaches, visual disturbances, and hemiparesis. All patients were successfully treated with endoscopic fenestration of the cyst wall into the lateral ventricle, where the wall was thinnest. Postoperatively, all patients reported improvement in their presenting symptoms, and neuroimaging demonstrated decompression of the cyst. Clinical follow-up ranged from 4 months to 5 years without evidence of reexpansion of the cyst or shunt requirement.Compared to open resection and shunting of the cyst contents, minimally invasive endoscopic fenestration of a glioependymal cyst into the ventricular system is a safe and effective surgical option. This approach is practical, is less invasive than open resection, and appears to provide a long-term solution.

Very Large Metastases to the Brain: Retrospective Study on Outcomes of Surgical Management.

BACKGROUND: The incidence of brain metastases is rising. To our knowledge, no published study focuses exclusively on brain metastases larger than 4 cm. We present our surgical outcomes for patients with brain metastases larger than 4 cm. METHODS: This is a retrospective chart review of inpatient data at our institution from January 2006 to September 2015. Primary end points included overall survival, progression-free survival, and local recurrence rate. RESULTS: Sixty-one patients had a total of 67 brain metastases larger than 4 cm: 52 were supratentorial and 15 were infratentorial. Forty-three patients underwent surgical resection. Average duration of disease freedom after resection was 4.79 months (range, 0-30 months). Excluding patients with residual on immediate postoperative magnetic resonance imaging, the average rate of local recurrence was 7 months (range, 1-14 months). Overall survival after surgery excluding patients who chose palliation in the immediate postoperative period averaged 8.76 months (range, 1-37 months). Thirty-five of 43 patients (81.4%) had stable or improved neurologic examinations postoperatively. Six patients (13.95%) developed surgical complications. There were 3 major complications (6.98%): 2 pseudomeningoceles required intervention and 1 postoperative hematoma required external ventricular drain placement. There were 3 minor complications (6.98%): 1 self-limited pseudomeningocele, 1 subgaleal fluid collection, and 1 postoperative seizure. CONCLUSIONS: Surgery resulted in stable or improved neurologic examination in 81.4% of cases. On statistical analysis, significantly increased overall survival was noted in patients undergoing surgical resection, and those with higher Karnofsky Performance Scale and lower number of brain metastases at presentation. There is a need for further studies to evaluate management of brain metastases larger than 4 cm.

Socioeconomic Factors Affecting Discharge Status of Patients with Uncomplicated Transsphenoidal Adenohypophysectomy.

Objectives The number of transsphenoidal adenohypophysectomies (TSAs) surgeries has grown significantly since 1993. While there has been an overall decreasing trend in length of stay (LOS), socioeconomic factors may impact hospitalization. This study explores the impact of socioeconomic factors on LOS and total charges in uncomplicated patients undergoing TSA. Design Retrospective cohort. Setting 2009 to 2013 Nationwide Inpatient Sample. Participants Patients undergoing TSA without medical complications. Main Outcomes Measures LOS and total charges. Results A total of 6,457 patients were identified, of which 17.2% had secreting tumors. Patients with secreting tumors stayed 2.95 days versus those with nonsecreting tumors stayed 3.26 days ( p < 0.001). Discharge to other than self-care was the largest contributing variable for both subsets, increasing both LOS and total charges. Patient factors that drove longer LOS and increased total charges for both subsets included metropolitan domicile, having a lower median income, Hispanic ethnicity, and having an increased amount of Agency for Healthcare Research and Quality (AHRQ) comorbidity indices. Having private insurance predicted a shorter LOS and lower total charges. Conclusions These results demonstrate that, even without complications, patients can be delayed in their discharge. While several socioeconomic factors significantly predict LOS and charges, the discharge disposition ultimately has the greatest effect. This suggests that efforts should focus on improving organizational factors such as coordination with social work and outside facilities to decrease LOS and charges for this patient population.

Safety, Efficacy, and Cost-Analysis of Percutaneous Endoscopic Gastrostomy and Ventriculoperitoneal Shunt Placement in a Simultaneous Surgery.

BACKGROUND: Limited historical data suggest that concomitant placement of both a ventriculoperitoneal (VP) shunt and percutaneous endoscopic gastrostomy (PEG) tube is associated with an increased risk of complications, including VP shunt infections. Here we compare the outcomes and cost difference between 2 groups of patients, one in which a VP shunt and PEG tube were placed in the same operation and the other in which separate operations were performed. METHODS: A total of 10 patients underwent simultaneous placement of a VP shunt and PEG tube. This group was compared with a group of 18 patients that underwent separate placements. Hospital billing charges were used to compare the total cost of the procedures in the 2 groups. RESULTS: Eight of the 10 patients presented with aneurysmal subarachnoid hemorrhage. The average length of stay was 25 ± 2 days for the simultaneous procedure group and 43 ± 7 days for the separate procedures group. The average duration of follow-up was 12 ± 3 months after simultaneous placement. No patient in the simultaneous surgery group had signs of infection or shunt malfunction at last follow-up. The overall complication rate was significantly lower in the simultaneous surgery group. A cost analysis demonstrated significant cost savings by completing both procedures in the same surgical procedure. CONCLUSIONS: Simultaneous placement of a PEG tube and VP shunt is safe, efficacious, and cost-effective. Thus, in patients requiring both a VP shunt and PEG tube, placement of both devices in a single surgical procedure should be considered.

Malignant glioma-primitive neuroectodermal tumor recurring as PNET-like only subdural collection: Case report.

BACKGROUND: Histologic variants of conventional glioblastoma are rare clinical entities. In recent years, an aggressive variant termed malignant glioma with primitive neuroectodermal tumor components (MG-PNET) has been described in adults. In addition to the rarity of supratentorial primitive neuroectdoermal tumors (sPNET) in adults, MG-PNET can present with unique radiographic features. CASE DESCRIPTION: We report the case of a 42-year-old male who presented with headaches and vision changes. Magnetic resonance imaging (MRI) of the brain revealed a large right frontal lesion. He underwent craniotomy with pathology demonstrating glioblastoma WHO grade IV, with primitive neuroectodermal tumor-like components (MG-PNET). Seven weeks later the patient represented with worsening headaches and left-hand weakness. MRI brain revealed a diffusion restricting subdural collection overlying the prior craniotomy site. Biopsy revealed PNET-like recurrence of the previously treated MG-PNET. CONCLUSION: In addition to histologic deviation, MG-PNET can present with variable radiographic findings on MRI and a clinical course distinctive from traditional glioblastoma. The hypercellular nature of this lesion can present as a diffusion-restricting lesion.

Herniated gyrus rectus causing idiopathic compression of the optic chiasm.

Anomalies in the frontal lobe can interfere with visual function by compression of the optic chiasm and nerve. The gyrus rectus is located at the anterior cranial fossa floor superior to the intracranial optic nerves and chiasm. Compression of these structures by the gyrus rectus is often caused by neoplastic or dysplastic growth in the area. We report a rare case of a herniated gyrus rectus impinged on the optic chiasm and nerve without a clear pathological cause for the herniation.

Meningioma consistency prediction utilizing tumor to cerebellar peduncle intensity on T2-weighted magnetic resonance imaging sequences: TCTI ratio.

OBJECTIVE Meningioma consistency, firmness or softness as it relates to resectability, affects the difficulty of surgery and, to some degree, the extent of resection. Preoperative knowledge of tumor consistency would affect preoperative planning and instrumentation. Several methods of prediction have been proposed, but the majority lack objectivity and reproducibility or generalizability to other surgeons. In a previous pilot study of 20 patients the authors proposed a new method of prediction based on tumor/cerebellar peduncle T2-weighted imaging intensity (TCTI) ratios in comparison with objective intraoperative findings. In the present study they sought validation of this method. METHODS Magnetic resonance images from 100 consecutive patients undergoing craniotomy for meningioma resection were evaluated preoperatively. During surgery a consistency grade was prospectively applied to lesions by the operating surgeon, as determined by suction and/or cavitron ultrasonic surgical aspirator (CUSA) intensity. Consistency grades were A, soft; B, intermediate; and C, fibrous. Using T2-weighted MRI sequences, TCTI ratios were calculated. Analysis of the TCTI ratios and intraoperative tumor consistency was completed with ANOVA and receiver operating characteristic curves. RESULTS Of the 100 tumors evaluated, 50 were classified as soft, 29 as intermediate, and 21 as firm. The median TCTI ratio for firm tumors was 0.88; for intermediate tumors, 1.5; and for soft tumors, 1.84. One-way ANOVA comparing TCTI ratios for these groups was statistically significant (p < 0.0001). A single cutoff TCTI value of 1.41 for soft versus firm tumors was found to be 81.9% sensitive and 84.8% specific. CONCLUSIONS The authors propose this T2-based method of tumor consistency prediction with correlation to objective intraoperative consistency. This method is quantifiable and reproducible, which expands its usability. Additionally, it places tumor consistency on a graded continuum in a clinically meaningful way that could affect preoperative surgical planning.

Aneurysmal bone cyst of the cervical spine in a child: case report and review of the surgical role.

BACKGROUND: Surgical treatment of aneurysmal bone cysts of the cervical spine, frequently affecting pediatric patients, is a challenge to operating surgeons. Complete tumor resection offers the best chance for cure. CASE DESCRIPTION: We present the case of a child with an expansile aneurysmal bone cyst of the cervical spine that involves all 3 spinal columns. The advantages of combining a posterolateral followed by anterior approach after a preoperative angiography and vertebral artery balloon occlusion testing provided the added safety to maximize the extent of tumor resection. Spinal stabilization was successfully achieved in both approaches. CONCLUSION: The challenge of surgically resecting aneurysmal bone cysts of the cervical spine in children enabled us to achieve a total resection with the help of preoperative angiography and vertebral artery balloon occlusion testing. Spinal instability should be addressed with reconstruction and stabilization techniques.

Three-Dimensional Printed Model Used to Teach Skull Base Anatomy Through a Transsphenoidal Approach for Neurosurgery Residents.

BACKGROUND: Skull base anatomy through a transsphenoidal approach is challenging for the neurosurgical resident to conquer. OBJECTIVE: To demonstrate that stereolithography, or 3-dimensional (3-D) printing, is a useful educational tool for neurosurgery residents to learn skull base anatomy. METHODS: Before any formal teaching, residents were brought into the operating room where they were asked to identify key structures seen through an endoscopic transsphenoidal approach. Scoring was based on correctly naming the anatomical structures. After the initial testing, all residents participated in a didactic lecture reviewing this anatomy by using 2-dimensional pictures. Residents were then divided into 2 groups: A and B. Group B residents were additionally taught through neurosurgical simulation using a 3-D printed model and an endoscope. Following all formal teaching, residents were retested in the operating room. RESULTS: A maximum score of 8 points was possible if all structures were identified correctly. Group A had mean scores of 2.75 on initial testing compared with 5 after the lecture (P = .041 using 2-tailed t test). Group B had mean scores of 2.75 on initial testing compared with 7.5 after the lecture and 3-D model simulation (P = .002). When comparing mean scores after formal teaching in groups A and B, 5 vs 7.5 were obtained for lecture only vs lecture and 3-D model simulation, respectively (P = .031). CONCLUSION: Three-dimensional models used in neurosurgical simulation to teach skull base anatomy through a transsphenoidal approach showed objective and subjective improvement in testing scores in neurosurgery residents. This study confirms that 3-D models are a useful educational tool.