Lumbar disc herniation: Epidemiology, clinical and radiologic diagnosis WFNS spine committee recommendations

Objective

To formulate the most current, evidence-based recommendations regarding the epidemiology, clinical diagnosis, and radiographic diagnosis of lumbar herniated disk (LDH).

Methods

A systematic literature search in PubMed, MEDLINE, and CENTRAL was performed from 2012 to 2022 using the search terms "herniated lumbar disc", "epidemiology", "prevention" "clinical diagnosis", and "radiological diagnosis". Screening criteria resulted in 17, 16, and 90 studies respectively that were analyzed regarding epidemiology, clinical diagnosis, and radiographic diagnosis of LDH. Using the Delphi method and two rounds of voting at two separate international meetings, ten members of the WFNS (World Federation of Neurosurgical Societies) Spine Committee generated eleven final consensus statements.

Results

The lifetime risk for symptomatic LDH is 1-3%; of these, 60-90% resolve spontaneously. Risk factors for LDH include genetic and environmental factors, strenuous activity, and smoking. LDH is more common in males and in 30-50 year olds. A set of clinical tests, including manual muscle testing, sensory testing, Lasegue sign, and crossed Lasegue sign are recommended to diagnose LDH. Magnetic resonance imaging (MRI) is the gold standard for confirming suspected LDH.

Conclusions

These eleven final consensus statements provide current, evidence-based guidelines on the epidemiology, clinical diagnosis, and radiographic diagnosis of LDH for practicing spine surgeons worldwide.

Cauda equina, conus medullaris and syndromes mimicking sciatic pain: WFNS spine committee recommendations

Introduction

Cauda equina syndrome (CES), conus medullaris syndrome (CMS), and sciatica-like syndromes or "sciatica mimics" (SM) may present as diagnostic and/or therapeutic dilemmas for the practicing spine surgeon. There is considerable controversy regarding the appropriate definition and diagnosis of these entities, as well as indications for and timing of surgery. Our goal is to formulate the most current, evidence-based recommendations for the definition, diagnosis, and management of CES, CMS, and SM syndromes.

Methods

We performed a systematic literature search in PubMed from 2012 to 2022 using the keywords "cauda equina syndrome", "conus medullaris syndrome", "sciatica", and "sciatica mimics". Standardized screening criteria yielded a total of 43 manuscripts, whose data was summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Utilizing the Delphi method, we generated seven final consensus statements.

Results and conclusion

s: We provide standardized definitions of cauda equina, cauda equina syndrome, conus medullaris, and conus medullaris syndrome. We advocate for the use of the Lavy et al classification system to categorize different types of CES, and recommend urgent MRI in all patients with suspected CES (CESS), considering the low sensitivity of clinical examination in excluding CES. Surgical decompression for CES and CMS is recommended within 48 h, preferably within less than 24 h. There is no data regarding the role of steroids in acute CES or CMS. The treating physician should be cognizant of a variety of other pathologies that may mimic sciatica, including piriformis syndrome, and how to manage these.

Augmented Reality to Compensate for Navigation Inaccuracies

This study aims to report on the capability of microscope-based augmented reality (AR) to evaluate registration and navigation accuracy with extracranial and intracranial landmarks and to elaborate on its opportunities and obstacles in compensation for navigation inaccuracies. In a consecutive single surgeon series of 293 patients, automatic intraoperative computed tomography-based registration was performed delivering a high initial registration accuracy with a mean target registration error of 0.84 ± 0.36 mm. Navigation accuracy is evaluated by overlaying a maximum intensity projection or pre-segmented object outlines within the recent focal plane onto the in situ patient anatomy and compensated for by translational and/or rotational in-plane transformations. Using bony landmarks (85 cases), there was two cases where a mismatch was seen. Cortical vascular structures (242 cases) showed a mismatch in 43 cases and cortex representations (40 cases) revealed two inaccurate cases. In all cases, with detected misalignment, a successful spatial compensation was performed (mean correction: bone (6.27 ± 7.31 mm), vascular (3.00 ± 1.93 mm, 0.38° ± 1.06°), and cortex (5.31 ± 1.57 mm, 1.75° ± 2.47°)) increasing navigation accuracy. AR support allows for intermediate and straightforward monitoring of accuracy, enables compensation of spatial misalignments, and thereby provides additional safety by increasing overall accuracy.

Dynamics in the Neurotrauma Catchment Area of a German University Hospital during the COVID-19 Pandemic

Objective: At the beginning of 2020, the COVID-19 pandemic enforced a rapid reallocation of healthcare resources. Our neurosurgical department is located in the German county of Marburg−Biedenkopf, about 80 km from the nearest major city. We were able to maintain our previously established open-door policy after the emergence of COVID-19. Here, we report on dynamics in the catchment area for neurotrauma patients at our department during the pandemic. Methods: 763 consecutive neurotrauma cases admitted to our department between 1 January 2018 and 31 December 2021 were analyzed retrospectively. Patients’ age, gender, origin, diagnoses, and outcomes were recorded. The number of patients hospitalized with a COVID-19 infection in Germany (PHCG) were retrieved from the Robert Koch Institute (RKI). We defined calendar weeks with >1000 PHCG as high COVID-19 caseload weeks (HCLW). Chi-square and Fisher’s exact served as statistical tests. Results: In 2020 and 2021, we observed a significantly increased number of neurotrauma patients who, with primary residence outside of our district, were admitted to our hospital compared to 2018 and 2019 (p < 0.001), while there were no significant differences in in-house mortality. During HCLW, a significantly increased number of neurotrauma patients with primary residence in the densely populated southwestern margin (SWM) of the contiguous part of our catchment area were referred to us compared to the time prior to the pandemic and between HCLW (p = 0.003). In neurotrauma patients admitted from the SWM during HCLW, there was no tendency towards higher in-house mortality. Conclusion: An open-door policy may moderate the risk of involuntarily triaging neurotrauma patients during a pandemic.

Navigated Intraoperative 3D Ultrasound in Glioblastoma Surgery: Analysis of Imaging Features and Impact on Extent of Resection

Background

Neuronavigation is routinely used in glioblastoma surgery, but its accuracy decreases during the operative procedure due to brain shift, which can be addressed utilizing intraoperative imaging. Intraoperative ultrasound (iUS) is widely available, offers excellent live imaging, and can be fully integrated into modern navigational systems. Here, we analyze the imaging features of navigated i3D US and its impact on the extent of resection (EOR) in glioblastoma surgery.

Methods

Datasets of 31 glioblastoma resection procedures were evaluated. Patient registration was established using intraoperative computed tomography (iCT). Pre-operative MRI (pre-MRI) and pre-resectional ultrasound (pre-US) datasets were compared regarding segmented tumor volume, spatial overlap (Dice coefficient), the Euclidean distance of the geometric center of gravity (CoG), and the Hausdorff distance. Post-resectional ultrasound (post-US) and post-operative MRI (post-MRI) tumor volumes were analyzed and categorized into subtotal resection (STR) or gross total resection (GTR) cases.

Results

The mean patient age was 59.3 ± 11.9 years. There was no significant difference in pre-resectional segmented tumor volumes (pre-MRI: 24.2 ± 22.3 cm³; pre-US: 24.0 ± 21.8 cm³). The Dice coefficient was 0.71 ± 0.21, the Euclidean distance of the CoG was 3.9 ± 3.0 mm, and the Hausdorff distance was 12.2 ± 6.9 mm. A total of 18 cases were categorized as GTR, 10 cases were concordantly classified as STR on MRI and ultrasound, and 3 cases had to be excluded from post-resectional analysis. In four cases, i3D US triggered further resection.

Conclusion

Navigated i3D US is reliably adjunct in a multimodal navigational setup for glioblastoma resection. Tumor segmentations revealed similar results in i3D US and MRI, demonstrating the capability of i3D US to delineate tumor boundaries. Additionally, i3D US has a positive influence on the EOR, allows live imaging, and depicts brain shift.

The Metalloprotease-Disintegrin ADAM8 Alters the Tumor Suppressor miR-181a-5p Expression Profile in Glioblastoma Thereby Contributing to Its Aggressiveness

Glioblastoma (GBM) as the most common and aggressive brain tumor is characterized by genetic heterogeneity, invasiveness, radio-/chemoresistance, and occurrence of GBM stem-like cells. The metalloprotease-disintegrin ADAM8 is highly expressed in GBM tumor and immune cells and correlates with poor survival. In GBM, ADAM8 affects intracellular kinase signaling and increases expression levels of osteopontin/SPP1 and matrix metalloproteinase 9 (MMP9) by an unknown mechanism. Here we explored whether microRNA (miRNA) expression levels could be regulators of MMP9 expression in GBM cells expressing ADAM8. Initially, we identified several miRNAs as dysregulated in ADAM8-deficient U87 GBM cells. Among these, the tumor suppressor miR-181a-5p was significantly upregulated in ADAM8 knockout clones. By inhibiting kinase signaling, we found that ADAM8 downregulates expression of miR-181a-5p via activation of signal transducer and activator of transcription 3 (STAT3) and mitogen-activated protein kinase (MAPK) signaling suggesting an ADAM8-dependent silencing of miR-181a-5p. In turn, mimic miR-181a-5p transfection caused decreased cell proliferation and lower MMP9 expression in GBM cells. Furthermore, miR-181a-5p was detected in GBM cell-derived extracellular vesicles (EVs) as well as patient serum-derived EVs. We identified miR-181a-5p downregulating MMP9 expression via targeting the MAPK pathway. Analysis of patient tissue samples (n=22) revealed that in GBM, miR-181a-5p is strongly downregulated compared to ADAM8 and MMP9 mRNA expression, even in localized tumor areas. Taken together, we provide evidence for a functional axis involving ADAM8/miR-181a-5p/MAPK/MMP9 in GBM tumor cells.

Extreme lateral interbody fusion (XLIF) in a consecutive series of 72 patients

Extreme lateral interbody fusion (XLIF) has become the standard of minimally invasive lumbar segmental scoliosis treatment. Our objective is to determine the safety and efficacy of XLIF in spinal canal stenosis (SCS) and spondylodiscitis (SD). Patients treated with XLIF in our department between 2012 and 2018 were retrospectively analyzed. Patient records with clinical and radiographical parameters were evaluated. The patient cohort consists of 40 male and 32 female patients with a median age of 66.6 years. Forty-five patients had an SCS and 27 patients SD. The mean follow-up was 23 months. One level XLIF was performed in 49 patients, 2 levels in 15, 3 levels in 7 patients and 4 levels in 1 patient. All but one patient received an additional dorsal stabilization. The pain was present in all patients with a mean visual analog scale (VAS) score of 8.8 versus postoperative VAS of 2.8 (p < 0.05). Preoperative neurological deficits were found in 44 patients. Only 6 patients had a neurological deterioration, 45 patients improved, and 21 patients remained unchanged. One patient experienced a perioperative complication. Non-fusion occurred in 8 cases. There were no outcome differences regarding pain and radiological outcome between patients with SCS and SD as well as between patients with one level vs. multilevel surgery. Baseline characteristics and the radiological outcome did not differ between the two groups. Patients with SD had a higher rate of worsening of neurological deficits following surgery, a higher rate of non-fusion, and a longer hospital stay. Patients with spinal canal stenosis SCS had a longer surgery time and more frequent adjacent segment disease.

Utilizing Intraoperative Navigated 3D Color Doppler Ultrasound in Glioma Surgery

Background

In glioma surgery, the patient’s outcome is dramatically influenced by the extent of resection and residual tumor volume. To facilitate safe resection, neuronavigational systems are routinely used. However, due to brain shift, accuracy decreases with the course of the surgery. Intraoperative ultrasound has proved to provide excellent live imaging, which may be integrated into the navigational procedure. Here we describe the visualization of vascular landmarks and their shift during tumor resection using intraoperative navigated 3D color Doppler ultrasound (3D iUS color Doppler).

Methods

Six patients suffering from glial tumors located in the temporal lobe were included in this study. Intraoperative computed tomography was used for registration. Datasets of 3D iUS color Doppler were generated before dural opening and after tumor resection, and the vascular tree was segmented manually. In each dataset, one to four landmarks were identified, compared to the preoperative MRI, and the Euclidean distance was calculated.

Results

Pre-resectional mean Euclidean distance of the marked points was 4.1 ± 1.3 mm (mean ± SD), ranging from 2.6 to 6.0 mm. Post-resectional mean Euclidean distance was 4.7. ± 1.0 mm, ranging from 2.9 to 6.0 mm.

Conclusion

3D iUS color Doppler allows estimation of brain shift intraoperatively, thus increasing patient safety. Future implementation of the reconstructed vessel tree into the navigational setup might allow navigational updating with further consecutive increasement of accuracy.

Lessons Learned from Developing Digital Teaching Modules for Medical Student Education in Neurosurgery during the COVID-19 Pandemic

BACKGROUND

The coronavirus 2019 (COVID-19) pandemic forced students and teachers to rapidly adopt digital education methods. Proper guidance for and refinement of such methods is continuously required. Here, we report on the educational experience students and academic staff at the neurosurgical department of a German university hospital made with digital teaching modules (DTMs) that were newly developed due to the transition to digital teaching during the first year of the COVID-19 pandemic and on the insights gained therefrom.

METHODS

Nine newly created DTMs provided students the option to anonymously evaluate each module by assigning a score from 0 (worst value) to 5 (best value) to it. Access count, evaluation count, average evaluation, number of included (interactive) figures, number of presented cases, number of linked publications, and number of included multiple-choice questions for each DTM were recorded retrospectively. For each DTM, we aimed to correlate access count, evaluation count, and average evaluation with the number of included (interactive) figures, number of presented cases, number of linked publications, and number of included multiple-choice questions. E-mail responses from individual students as to the DTMs were collected. Among students, an anonymous, voluntary online survey regarding the DTMs was conducted.

RESULTS

Number of figures and average evaluation per DTM were significantly positively correlated (Spearman's rho = 0.85; p = 0.0037). Number of figures and number of evaluations per DTM were also significantly positively correlated (Spearman's rho = 0.78; p = 0.0137). Responses from individual students indicated that illustrative cases and interactive figures might further increase DTM popularity.

CONCLUSION

As a valuable adjunct in medical student education, DTMs should contain (interactive) figures, illustrative cases, a scoring option, and the option to give individual feedback towards the academic staff.

Microsurgical resection of giant T11/T12 conus cauda equina schwannoma

In this video, we highlight the anatomy involved with microsurgical resection of a giant T11/T12 conus cauda equina schwannoma. Spinal schwannoma remains the third most common intradural spinal tumor. Tumors undergoing gross total resection usually do not recur. To our knowledge, this is the first video case report of giant cauda equina schwannoma resection. A 55-year-old female presented with paraparesis and urinary retention. Lumbar spine MRI revealed a contrast-enhancing intradural extramedullary tumor at the T11/T12 level. Surgery was performed in the prone position with intraoperative neurophysiology monitoring (somatosensory and motor evoked potentials-SSEPs and MEPs). T11/T12 laminectomies were performed. After opening the dura and arachnoid, the tumor was found covered with cauda equina nerve roots. We delineated the inferior pole of the tumor, followed by opening of the capsule and debulking the tumor. Subsequently, the cranial pole was dissected from the corresponding cauda equina nerve roots. Finally, the tumor nerve origin was identified and divided after nerve stimulation confirmed the tumor arose from a sensory nerve root. The tumor was removed; histological analysis revealed a schwannoma (WHO Grade I). Postoperative MRI revealed complete resection. The patient fully recovered her neurological function. This case highlights the importance of careful microsurgical technique and gross total resection of the tumor in the view of favorable postoperative neurological recovery of the patient. Intraoperative use of ultrasound is helpful to delineate preoperatively tumor extension and confirm postoperative tumor resection.

The 270° Circumferential Microsurgical Decompression of the Foramen Magnum in Adult Chiari Malformation Type I: Single Surgeon Series of 130 Patients with Syringomyelia, Neurologic, and Headache Outcomes

OBJECTIVE

Chiari malformation type I (CM-I) is a craniocervical junction disorder associated with descent of the cerebellar tonsils >5 mm. The prevalence of CM-I is common, including 0.5%-3.5% in the general population, 0.56%-0.77% on magnetic resonance imaging, and 0.62% in anatomic dissection studies. We sought to measure our surgical outcomes related to resolution/improvement of headaches, neurologic outcomes, and syringomyelia compared with reported adult CM-I studies from 2000-2019.

METHODS

From December 2003 to June 2018, the first author (K.I.A.) performed 270° circumferential decompression on adult (>18 years) patients with CM-I. At admission and follow-up, all parameters were numerically evaluated; headaches were self-reported on the visual analog scale, neurologic condition was evaluated using Karnofsky Performance Status and European Myelopathy Score, and syrinx width (if present) was measured on magnetic resonance imaging by grades I-IV. All parameters were analyzed, compared, and statistically tested. We compared results with our previously reported and updated systematic review of operative adult CM-I studies (studies from 2000 to 2019).

RESULTS

In our series, 118/121 (98%) experienced headache improvements and 100% experienced neurologic improvements. Complete syrinx resolution was experienced by 35/43 (81%); 8 (19%) showed significant improvement. In data from reported studies (2000-2019), only 79% experienced headache resolution, 77% improvement of neurologic status, and 74% resolution/improvement of syrinx (mean).

CONCLUSIONS

Our modified 270° circumferential microsurgical foramen magnum decompression for adult CM-I appears to be beneficial in improvement of outcomes, namely in resolution of the syrinx, neurologic symptoms, and headaches. We also confirm the association of body mass index with CM-I. Further studies are needed to confirm our results.

Comparing Fiducial-Based and Intraoperative Computed Tomography-Based Registration for Frameless Stereotactic Brain Biopsy

OBJECTIVE

The aim of this work was to compare fiducial-based and intraoperative computed tomography (iCT)-based registration for frameless stereotactic brain biopsy.

METHODS

Of 50 frameless stereotactic biopsies with the VarioGuide, 30 cases were registered as iCT based and 20 as fiducial based. Statistical analysis of the target registration error (TRE), dose length product, effective radiation dose (ED), operation time, and diagnostic yield was performed.

RESULTS

The mean TRE was significantly lower using iCT-based registration (mean ± SD: 0.70 ± 0.32 vs. 2.43 ± 0.73 mm, p < 0.0001). The ED was significantly lower when using iCT-based registration compared to standard navigational CT (mean ± SD: 0.10 ± 0.13 vs. 2.23 ± 0.34 mSv, p < 0.0001). Post-biopsy iCT was associated with a significant lower (p < 0.0001) ED compared to standard CT (mean ± SD: 1.04 ± 0.18 vs. 1.65 ± 0.26 mSv). The mean surgical time was shorter using iCT-based registration, although the mean total operating room (OR) time did not differ significantly. The diagnostic yield was 96.7% (iCT group) versus 95% (fiducial group). Post-biopsy imaging revealed severe bleeding in 3.3% (iCT group) versus 5% (fiducial group).

CONCLUSION

iCT-based registration for frameless stereotactic biopsies increases the accuracy significantly without negative effects on the surgical time or the overall time in the OR. Appropriate scan protocols in iCT registration contribute to a significant reduction of the radiation exposure. The high accuracy of the iCT makes it the more favorable registration strategy when taking biopsies of small tumors or lesions near eloquent brain areas.

Spine Surgery Supported by Augmented Reality

STUDY DESIGN

A prospective, case-based, observational study.

OBJECTIVES

To investigate how microscope-based augmented reality (AR) support can be utilized in various types of spine surgery.

METHODS

In 42 spinal procedures (12 intra- and 8 extradural tumors, 7 other intradural lesions, 11 degenerative cases, 2 infections, and 2 deformities) AR was implemented using operating microscope head-up displays (HUDs). Intraoperative low-dose computed tomography was used for automatic registration. Nonlinear image registration was applied to integrate multimodality preoperative images. Target and risk structures displayed by AR were defined in preoperative images by automatic anatomical mapping and additional manual segmentation.

RESULTS

AR could be successfully applied in all 42 cases. Low-dose protocols ensured a low radiation exposure for registration scanning (effective dose cervical 0.29 ± 0.17 mSv, thoracic 3.40 ± 2.38 mSv, lumbar 3.05 ± 0.89 mSv). A low registration error (0.87 ± 0.28 mm) resulted in a reliable AR representation with a close matching of visualized objects and reality, distinctly supporting anatomical orientation in the surgical field. Flexible AR visualization applying either the microscope HUD or video superimposition, including the ability to selectively activate objects of interest, as well as different display modes allowed a smooth integration in the surgical workflow, without disturbing the actual procedure. On average, 7.1 ± 4.6 objects were displayed visualizing target and risk structures reliably.

CONCLUSIONS

Microscope-based AR can be applied successfully to various kinds of spinal procedures. AR improves anatomical orientation in the surgical field supporting the surgeon, as well as it offers a potential tool for education.

Reliable navigation registration in cranial and spine surgery based on intraoperative computed tomography

OBJECTIVE

Low registration errors are an important prerequisite for reliable navigation, independent of its use in cranial or spinal surgery. Regardless of whether navigation is used for trajectory alignment in biopsy or implant procedures, or for sophisticated augmented reality applications, all depend on a correct registration of patient space and image space. In contrast to fiducial, landmark, or surface matching–based registration, the application of intraoperative imaging allows user-independent automatic patient registration, which is less error prone. The authors’ aim in this paper was to give an overview of their experience using intraoperative CT (iCT) scanning for automatic registration with a focus on registration accuracy and radiation exposure.

METHODS

A total of 645 patients underwent iCT scanning with a 32-slice movable CT scanner in combination with navigation for trajectory alignment in biopsy and implantation procedures (n = 222) and for augmented reality (n = 437) in cranial and spine procedures (347 craniotomies and 42 transsphenoidal, 56 frameless stereotactic, 59 frame-based stereotactic, and 141 spinal procedures). The target registration error was measured using skin fiducials that were not part of the registration procedure. The effective dose was calculated by multiplying the dose length product with conversion factors.

RESULTS

Among all 1281 iCT scans obtained, 1172 were used for automatic patient registration (645 initial registration scans and 527 repeat iCT scans). The overall mean target registration error was 0.86 ± 0.38 mm (± SD) (craniotomy, 0.88 ± 0.39 mm; transsphenoidal, 0.92 ± 0.39 mm; frameless, 0.74 ± 0.39 mm; frame-based, 0.84 ± 0.34 mm; and spinal, 0.80 ± 0.28 mm). Compared with standard diagnostic scans, a distinct reduction of the effective dose could be achieved using low-dose protocols for the initial registration scan with mean effective doses of 0.06 ± 0.04 mSv for cranial, 0.50 ± 0.09 mSv for cervical, 4.12 ± 2.13 mSv for thoracic, and 3.37 ± 0.93 mSv for lumbar scans without impeding registration accuracy.

CONCLUSIONS

Reliable automatic patient registration can be achieved using iCT scanning. Low-dose protocols ensured a low radiation exposure for the patient. Low-dose scanning had no negative effect on navigation accuracy.

Augmented reality in intradural spinal tumor surgery

BACKGROUND

Microscope-based augmented reality (AR) is commonly used in cranial surgery; however, until recently, this technique was not implemented for spinal surgery. We prospectively investigated, how AR can be applied for intradural spinal tumor surgery.

METHODS

For ten patients with intradural spinal tumors (ependymoma, glioma, hemangioblastoma, meningioma, and metastasis), AR was provided by head-up displays (HUDs) of operating microscopes. User-independent automatic AR registration was established by low-dose intraoperative computed tomography. The objects visualized by AR were segmented in preoperative imaging data; non-linear image registration was applied to consider spine flexibility.

RESULTS

In all cases, AR supported surgery by visualizing the tumor outline and other relevant surrounding structures. The overall AR registration error was 0.72 ± 0.24 mm (mean ± standard deviation), a close matching of visible tumor outline and AR visualization was observed for all cases. Registration scanning resulted in a low effective dose of 0.22 ± 0.16 mSv for cervical and 1.68 ± 0.61 mSv for thoracic lesions. The mean HUD AR usage in relation to microscope time was 51.6 ± 36.7%. The HUD was switched off and turned on again in a range of 2 to 17 times (5.7 ± 4.4 times). Independent of the status of the HUD, the AR visualization was displayed on monitors throughout surgery.

CONCLUSIONS

Microscope-based AR can be reliably applied to intradural spinal tumor surgery. Automatic AR registration ensures high precision and provides an intuitive visualization of the extent of the tumor and surrounding structures. Given this setting, all advanced multi-modality options of cranial AR can also be applied to spinal surgery.

Microsurgical Resection of Spinal Cord Hemangioblastoma: 2-Dimensional Operative Video

This video demonstrates microsurgical resection of spinal cord hemangioblastoma. Hemangioblastomas are rare, benign, highly vascularized tumors classified as grade I according to World Health Organization classification systems. About 3% of all intramedullary tumors are hemangioblastomas.1,2 Spinal cord hemangioblastomas are either sporadic3,4 or manifestations of von Hippel-Lindau (VHL) disease in 20% to 45% of patients.5,6 A 30-year-old male presented with sudden onset urinary incontinence. Magnetic resonance imaging showed contrast enhancing intramedullary tumor with adjacent cyst in T11, and syringomyelia extending to C1. Surgical resection followed rules that apply to resection of arteriovascular malformations: coagulation of arterial feeders precedes the coagulation of the draining vein, which is preserved until the end of surgery.2,4,5,7,8 First, posterior midline myelotomy was performed and the tumor cyst was drained in order to develop a dissection plane. Following this, we continuously separated dorsal nerve roots from the tumor nodule using microsurgical technique. The key step in tumor resection is devascularization of the tumor, achievable in 2 ways.2,7,9-13 The circumferential detachment of the normal pia from the tumor pia is crucial in developing a plane of dissection. The coagulation and division of arterial feeders while preserving the drainage vein further devascularizes the tumor. Once the tumor mural nodule was detached from the spinal cord, the drainage vein was coagulated last and the tumor was removed. The patient fully recovered from his incontinence and was neurologically intact. Screening for VHL disease was negative. Written consent was obtained directly from the patient.

Microsurgical Resection of Medulla Oblongata Hemangioblastoma: 2-Dimensional Operative Video

This video demonstrates the microsurgical resection of brainstem hemangioblastoma. The patient is a 32-yr-old woman with Von Hippel Lindau syndrome who presented with quadriparesis and inability to swallow. Magnetic resonance imaging (MRI) of the neuroaxis revealed a brainstem cystic lesion with contrast-enhancing tumor nodule right along the posterior aspect of the lower part of medulla oblongata. The surgery was performed in the prone position with suboccipital craniectomy and partial C1 posterior arch removal. The aim of the surgery was to remove the tumor nodule.^1-12

The tumor was separated from the right dorsal nerve roots, and then progressively dissected with coagulation of arterial feeders and draining vein and division of the pia circumferentially. Postoperative MRI revealed complete resection. The patient completely recovered from her quadriparesis and difficulty swallowing.

Retrospective study of 229 surgically treated patients with brain metastases: Prognostic factors, outcome and comparison of recursive partitioning analysis and diagnosis-specific graded prognostic assessment

Background:

Metastases are the most frequent tumors in the brain. Most often used scoring systems to predict the outcome are the RPA (Recursive Partitioning Analysis) classification and the DS-GPA (Diagnosis-Specific Graded Prognostic Assessment) score. The goal of our study was to determine prognostic factors which influence outcome in patients who undergo surgery for brain metastases and to compare different outcome scores.

Methods:

Two hundred and twenty-nine patients who underwent surgery for brain metastases in our institution between January 2005 and December 2014 were included in the study. Patient data were evaluated retrospectively.

Results:

The mean survival time was 19.2 months (median survival time, MST: 8 months), for patients with a single metastasis (n = 149) 17.6 months (MST: 8 months), and for patients with multiple metastases (n = 80) 17.9 months (MST: 6 months). Significant influence on MST had age <65 years (9 vs. 5 months, P = 0.002), female sex (10 vs. 6 months, P < 0.001), RPA Class I and II (11 vs. 4 months, P < 0.001), Karnofsky score >70% (11 vs. 4 months, P < 0.001), and postoperative radiotherapy (8 vs. 5 months, P < 0.002). To evaluate the diagnostic power of DS-GPA and RPA score in respect of survival, two Cox regressions were modeled, where the RPA classification showed a better predictive power.

Conclusion:

Favorable factors for prolonged survival were KPS >70%, RPA Class I and II, age <65 years, female sex, a DS-GPA Score of 2.5–3 and 3.5–4, and adjuvant radiotherapy. The RPA Classification was more accurate in predicting the outcome than the DS-GPA score.