Insights from a Multicenter Study on Adult H3 K27M-Mutated Glioma: Surgical Resection's Limited Influence on Overall Survival, ATRX as Molecular Prognosticator

BACKGROUND

H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 WHO classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults.

METHODS

We included molecularly confirmed H3 K27M-mutated glioma cases in patients >18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 + 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy.Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, p=0.007). Preoperative Karnofsky Performance Score (KPS) < 80 showed a reduced OS (4.2 vs. 18 months, p=0.02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, p=0.0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, p=0.4006).

CONCLUSION

The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

[Traumatic brain injury]

Traumatic brain injury (TBI) describes parenchymal brain damage caused by external forces to the head. It has a massive personal and socioeconomic impact, as it is a disease with high morbidity and mortality. Both young and old people are affected, as a result of traffic or sports accidents as well as due to falls at home. The term TBI encompasses various clinical pictures, differing considerably in cause, prognosis and therapy. What they all have in common is the pathophysiological cascade that develops immediately after the initial trauma and which can persist for several days and weeks. In this phase, medical treatment, whether surgical or pharmacological, attempts to reduce the consequences of the primary damage. The aim is to maintain adequate cerebral perfusion pressure and to reduce intracranial pressure.

P08.04.B The Clinical Frailty Scale is superior to the Karnofsky Performance Status as predictor of overall survival in patients with surgical treatment of brain metastases

Background

The Clinical Frailty Scale (CFS) evaluates patients’ level of frailty on a scale from 1 (very fit) to 9 (terminally ill) and is commonly used in geriatric medicine, intensive care and orthopaedics but not in patients harboring neuro-oncological diseases. Our study was conducted to reveal if the usage of CFS generates more reliable prediction of overall survival in patients after brain metastases resection rather than Karnofsky Performance Status (KPS).

Material and Methods

All patients which were operated for brain metastatic disease at our department from 2005-2019 were included. CFS and KPS were retrospectively assessed for the timepoints pre- and postoperatively as well during follow-up 3-6 months after resection.

Results

205 patients with mean follow-up of 22.8 months (CI95% 18.4-27.1) were evaluated. Mean estimated OS was 32.1 months (CI95% 25.0-39.1). CFS showed a median of 3 points (IqR 2-4) at all 3 assessment-points which means patients were “managing well”. Median KPS was 80 preoperative (IqR 80-90) and 90 (IqR 80-100) postoperative as well as on follow-up after 3-6 months. CFS strongly correlated with KPS: preoperatively (r=-0.92; p&lt; 0.001), postoperatively (r=-0.85; p&lt;0.001) and at follow-up (r=-0.93; p&lt;0.001). In the same time, CFS pre- and postoperatively showed only weak correlation with CFS at follow-up after 3-6 months (r=0.30, p&lt;0.001; and r=0.37, p&lt;0.001, correspondingly). In multivariate integrated Cox regression model, the CFS predicted the expected reduction of OS superior to KPS at all 3 assessment-points. One point increase of preoperative CFS represented 30% additional hazard to decease (HR=1.30, CI95% 1.15-1.46; p&lt;0.001), correspondingly postoperative CFS provides 39% (HR=1.39, CI95% 1.25-1.54; p&lt;0.001) and at follow-up 42% of hazard (HR= 1.42, CI95% 1.27-1.59; p&lt;0.001). In case of KPS, decrease of 10 points resulted in additional hazards to decease of 26% (HR=0.974/point, CI95% 0.962-0.987; p&lt;0.001) postoperatively 14% (HR=0.986/point, CI95% 0.978-0.993; p&lt;0.001) and 31% (HR=0.969/point, CI95% 0.959-0.978; p&lt;0.001) at follow-up.

Conclusion

CFS is a feasible and reliable performance scoring in patients undergoing brain metastasis resection, that provides better OS prediction as compared to KPS. Whereas, CFS at follow-up after 3-6 months specifies the expected OS most accurately. Due to weak correlation between CFS preoperatively vs. postoperatively and in 3-6 months, initial frailty does not predict the patients’ postoperative frailty score.

P12.05.B Impact of GAP-43 and actin expression on the outcome and overall survival in diffuse and anaplastic gliomas

Background

Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli (TMs), where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial epidemiologic, radiological and neuropathological prognostic factors.

Material and Methods

FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. Clinical, neuropathological as well as follow-up-data were gained from the institutional neuro-oncological database.

Results

118 patients with a median age of 46 years (IqR: 35 - 57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. 96 (82%) cases presented with intermediate or strong GAP-43 expression and 78 (67%) with no or light actin expression. Tumors with higher expression of GAP-43 (p=0.024, HR=1.71/rank) and actin (p&lt;0.001, HR=2.28/rank) showed significantly reduced OS. IDH wildtype glioma demonstrated significantly more expression of both proteins: GAP-43 (p=0.009) and actin (p&lt;0.001). The same was confirmed for anaplasia (GAP-43 p=0.028, actin p=0.029), higher proliferation rate (GAP-43 p=0.016, actin p=0.038), contrast-enhancement in MRI (GAP-43 p=0.023, actin p=0.037) and age (GAP-43 p=0.004, actin p&lt;0.001).

Conclusion

The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and unfavorable prognostic features.

OS02.7.A The role of epilepsy in elderly patients with Glioblastoma: An Austrian multicenter analysis

Background

Higher age is a significant predictor of poor outcome in glioblastoma multiforme (GBM) patients. Thus, acquisition of a better understanding of additional prognostic factors in these often-frail patients is of utmost importance. Epileptic seizures correlate with improved overall survival (OS) in low-grade gliomas; however, the impact of epilepsy in GBM patients on outcome parameters is poorly defined. Furthermore, persisting epilepsy significantly influences the patients’ quality of life (QoL). This study aims at specifically evaluating the impact of epilepsy in elderly GBM patients.

Material and Methods

Two Austrian academic neurosurgical centers retrospectively analyzed all elderly (≥65 years) GBM patients with de-novo tumors, who underwent tumor resections between 09/2006 and 07/2021. Epidemiological, histopathological and survival data were gained from patients’ electronic charts and screened for presence of epilepsy preoperatively or during follow-up.

Results

391 patients (55% males, 45% females) with a median age at surgery of 73 years (Interquartile Range (IqR) 68.5-77.5) were analyzed. The mean predicted OS was recorded to be 12.4 months (CI95% 10.9-14.0). Median preoperative Modified Rankin Scale (mRS) was 2 (IqR 1-3), and median preoperative Karnofsky performance score was 80 (IqR 60-90). Mean follow-up was 10.4 months (CI95% 9.1-11.6) in our cohort. 95/391 patients (24%) suffered from preoperative epilepsy. 17 (18%) patients still suffered from epilepsy after tumor resection with eight patients who developed new postoperative seizures, and four patients (1.0%) showed a worsening of already preoperatively diagnosed seizures. Major surgery-associated neurological complications included new motor deficits in 29 (7%) and new aphasia in 16 (4%) patients. Logistic regression showed, patients with seizures had significantly lower mRS (OR=0.735 [CI95% 0.563 0.961], p=0.032) and less frequently occipital tumor location (OR=0.347 [CI95% 0.152-0.791], p=0.018). Postoperative epilepsy resulted in significantly prolonged hospitalization after the surgery (OR=2.622[CI95% 1.496-3.979], p=0.009). Survival did not correlate with preoperative epilepsy (p&gt;0.05). However, Cox regression revealed that multifocal tumor location (HR=1.777 [CI95% 1.197-2.639], p=0.025) as well as thalamic involvement (HR=11.121 [CI95% 3.431-36,046], p=0.030) negatively influenced OS. Furthermore, surgery-associated complications shortened OS significantly (HR=1.945 [CI95% 1,296-2,916], p=0.025).

Conclusion

Even though epilepsy was not found to directly impact survival in elderly GBM patients, we found that surgery led to epilepsy freedom in a significant proportion of our patient cohort, thereby potentially leading to improved QoL. Greatest focus should be set on avoiding any surgery-associated deficits, since these severely influence the OS.

P11.10.A An assessment of predictive factors for overall survival in glioblastoma - MGMT methylation is solely important for younger patients

Background

Diverse groups of factors - neuropathological characters, tumor position and epidemiological data - have been proposed for outcome evaluation of glioblastoma (GBM). We compared clinical signs, neuropathological features and the locus of the tumor with the follow-up data.

Material and Methods

All adult patients with firstly diagnosed and histologically proven GBM (according to WHO 2016), which were operated in our center between January 2010 and June 2021 were retrospectively assessed. Epidemiological, clinical and neuro-pathological characteristics were acquired from our institutional neuro-oncological database.

Results

A total of 399 patients could be evaluated. The mean follow-up was 13.9 months (CI95 12.2-15.6), within 266 (67%) patients were deceased. Estimated mean OS for entire cohort was 24.2 months (CI95 19.8-28.7). Age, MGMT promoter methylation, brainstem localization or if a patient received biopsy only showed significant impact on OS. Each year of life accounted for 3.4% additional hazard to decease (HR=1.034, CI95 1.020-1.048, p&lt;0.001). If patients were younger than 65 years, mean OS was 34 months (CI95 26.5-41.8) compared to older than 65 years patients with a mean OS of 14.3 months (CI95 10.5-18.1, p&lt;0.001). Generally, an unmethylated MGMT promoter status was linked to 75% higher hazards to decease (HR 1.75, CI95 1.27-2.40, p=0.027). If MGMT promoter status was methylated, mean OS was 25.7 months (CI95 19.9-31.5) or more compared to unmethylated with 14.5 months (CI95 12.0-16.9, p=0.01). Presence of MGMT promoter methylation showed influence on OS only in the younger cohort (&lt;65y, mean OS 38.7 months [CI95 28.9-48.6]; HR 2.60 [CI95 1.55-4.37], p&lt;0.001) as opposed to unmethylated MGMT (mean OS 17.7 months [CI95 14.1-21.2], p&lt;0.001). In the older cohort (&gt;65y) presence of methylated MGMT promoter showed no significant difference (p=0.364). For patients who received only biopsy, 2.4 times more hazards for worse OS were revealed (HR 3.36, CI95% 2.30-4.90, p&lt;0.001). In these cases, mean OS was 7.1 months (CI95 5.3-8.8). Other factors, including gender or preoperative seizures, as well as EGFR, p53, IDH1, ATRX and TERT status did not show impact on OS in our series.

Conclusion

In our cohort, MGMT promoter methylation showed an impact on OS only in younger patients &lt;65 years of age. Biopsy of GBM should only be considered very selected patients when resection is not possible.

P08.02.B The Clinical Frailty Scale as predictor of overall survival after resection of high-grade glioma

Background

The Clinical Frailty Scale (CFS) describes the general level of fitness or frailty and is widely used in geriatric medicine, intensive care and orthopaedic surgery. This study was conducted to analyze, whether CFS could be used for patients with high-grade glioma.

Material and Methods

Patients harboring high-grade gliomas, undergoing first resection at our center between 2015 and 2020 were retrospectively evaluated. Patients’ performance was assessed using the Rockwood Clinical Frailty Scale and the Karnofsky Performance Scale (KPS) preoperatively and 3-6 months postoperatively.

Results

289 patients were included. Pre- as well as postoperative median frailty was 3 CFS points (IqR 2-4) corresponding to “managing well”. CFS strongly correlated with KPS preoperatively (r = -0.85; p &lt; 0.001) and at the 3-6 months follow-up (r = -0.90; p &lt; 0.001). The reduction of overall survival (OS) was 54% per point of CFS preoperatively (HR 1.54, CI95% 1.38-1.70; p &lt; 0.001) and 58% at the follow-up (HR 1.58, CI95% 1.41-1.78; p &lt; 0.001), comparable to KPS. Patients with IDH mutation showed significantly better preoperative and follow-up CFS and KPS (p &lt; 0.05). Age and performance scores correlated only mildly with each other (r = 0.21⋯0.35; p &lt; 0.01), but independently predicted OS (p &lt; 0.001 each).

Conclusion

CFS seems to be a reliable tool for functional assessment of patients suffering from high-grade glioma. CFS includes non-cancer related aspects and therefore is a contemporary approach for patient evaluation. Its projection of survival can be equally estimated before and after surgery. IDH-mutation caused longer survival and higher functionality.

Evaluate the safety and efficacy of dura sealant patch in reducing cerebrospinal fluid leakage following elective cranial surgery (ENCASE II): study protocol for a randomized, two-arm, multicenter trial

BACKGROUND

Cerebrospinal fluid (CSF) leakage is a frequent and challenging complication in neurosurgery, especially in the posterior fossa, with a prevalence of 8%. It is associated with substantial morbidity and increased healthcare costs. A novel dural sealant patch (LIQOSEAL) was developed for watertight dural closure. The objective of this study is to clinically assess the safety and effectiveness of LIQOSEAL as a means of reducing intra- as well as postoperative CSF leakage in patients undergoing elective posterior fossa intradural surgery with a dural closure procedure compared to the best currently available dural sealants.

METHODS

We will conduct a two-arm, randomized controlled, multicenter study with a 90-day follow-up. A total of 228 patients will be enrolled in 19 sites, of which 114 will receive LIQOSEAL and 114 an FDA-approved PEG sealant. The composite primary endpoint is defined as intraoperative CSF leakage at PEEP 20 cm H₂O, percutaneous CSF leakage within 90 days of, wound infection within 90 days of or pseudomeningocele of more than 20cc on MRI or requiring intervention. We hypothesize that the primary endpoint will not be reached by more than 10 patients (9%) in the investigational arm, which will demonstrate non-inferiority of LIQOSEAL compared to control.

DISCUSSION

This trial will evaluate whether LIQOSEAL is non-inferior to control as a means of reducing CSF leakage and safety TRIAL REGISTRATION: ClinicalTrials.gov NCT04086550 . Registered on 11 September 2019.

[Operative treatment of degenerative diseases of the lumbar spine]

BACKGROUND

Degenerative diseases of the lumbar spine and associated lower back pain represent a major epidemiological and health-related economic challenge. A distinction is made between specific and unspecific lower back pain. In specific lower back pain lumbar disc herniation and spinal canal stenosis with or without associated segment instability are among the most frequent pathologies. Diverse conservative and operative strategies for treatment of these diseases are available.

OBJECTIVES

The aim of this article is to present an overview of current data and an evidence-based assessment of the possible forms of treatment.

MATERIAL AND METHODS

An extensive literature search was carried out via Medline plus an additional evaluation of the authors' personal experiences.

RESULTS

Conservative and surgical treatment represent efficient treatment options for degenerative diseases of the lumbar spine. Surgical treatment of lumbar disc herniation shows slight advantages compared to conservative treatment consisting of faster recovery of neurological deficits and a faster restitution of pain control. Surgical decompression is superior to conservative measures for the treatment of spinal canal stenosis and degenerative spondylolisthesis. In this scenario conservative treatment represents an important supporting measure for surgical treatment in order to improve the mobility of patients and the outcome of surgical treatment.

CONCLUSION

The treatment of specific lower back pain due to degenerative lumbar pathologies represents an interdisciplinary challenge, requiring both conservative and surgical treatment strategies in a synergistic treatment concept in order to achieve the best results for patients.

[Operative treatment of the degenerative cervical spine]

BACKGROUND

Degenerative alterations of the cervical spine often entail disc herniations and stenoses of the spinal canal and/or neural foramen. Mediolateral or lateral compression of nerve roots causes cervical radiculopathy, which is an indication for surgery in cases of significant motor deficits or refractory pain. Median canal encroachment may result in compression of the spinal cord and cervical myelopathy. Its natural history is typically characterized by episodic deterioration, so that surgical decompression is indicated in cases of clear myelopathic signs.

OBJECTIVE

The aim of the present article is to outline the operative options for patients with cervical radiculopathy and myelopathy. Furthermore, we describe the operative complications and the outcome in these patients.

MATERIAL AND METHODS

For this manuscript a systematic PubMed search was carried out, the papers were systematically analyzed for the best evidence and this was combined with the authors' experience.

RESULTS AND CONCLUSION

Depending on the cervical pathology, the most prevalent surgical options for radiculopathy include anterior cervical discectomy and fusion (ACDF), cervical arthroplasty or posterior cervical foraminotomy. Cervical myelopathy may be decompressed by ACDF, corpectomy or posterior approaches like laminectomy plus instrumented fusion or laminoplasty. The outcome depends on the cervical pathology and the type of operation. Overall, in long-term follow-up studies the results of all surgical techniques on the cervical spine are generally considered to be very good, although specific patient characteristics are more suited for a particular approach.

How I do it-optimizing radiofrequency ablation in spinal metastases using iCT and navigation

BACKGROUND

Exact positioning of the radiofrequency ablation (RFA) probe for tumor treatment under fluoroscopic guidance can be difficult because of potentially small inaccessible lesions and the radiation dose to the medical staff in RFA. In addition, vertebroplasty (VP) can be significantly high.

METHOD

Description and workflow of RFA in spinal metastasis using iCT (intraoperative computed tomography) and 3D-navigation-based probe placement followed by VP.

CONCLUSION

RFA and VP can be successfully combined with iCT-based navigation, which leads to a reduction of radiation to the staff and optimal probe positioning due to 3D navigation.

Asymmetric pedicle subtractionosteotomy (aPSO) guided by a 3D-printed model to correct a combined fixed sagittal and coronal imbalance

Surgical correction of fixed thoracolumbar deformity is usually achieved by estimating the preoperatively planned correction angles during surgery and is therefore prone to inaccuracy. This is particularly problematic in biplanar deformities. To overcome these difficulties, 3D model for planning, preparation, and simulation of an asymmetric pedicle subtraction osteotomy (aPSO) was printed and used to realign coronal and sagittal balance in case of rigid degenerative kyphoscoliosis. A 59-year-old woman presented with severe back pain and spinal claudication and was diagnosed with a rigid kyphoscoliosis with multilevel spinal stenosis. Spino-pelvic parameters were measured preoperatively (pelvic incidence 47° [PI], lumbar lordosis 18° [LL]; pelvic tilt 42° [PT], T1 pelvic angle 40° [TPA], Cobb angle 33°, sagittal vertical axis 10.5 cm [SVA]). To aid the complex deformity in the sagittal and coronal plane, a 1:1 3D model of the spine was printed according to the preoperative computed tomography (CT). With the use of a rebalancing software, the spine was prepared in vitro as a model for intraoperative realignment and the correction was preoperatively simulated. Surgery was accomplished according to the preoperative software-guided plan. Asymmetric pedicle subtraction osteotomy (aPSO) of L3 identical to the 3D model was performed. Additionally, a Smith-Peterson osteotomy of L4/5 with transforaminal lumbar interbody fusion (TLIF) and laminectomy of L2-S1 with pedicle screw instrumentation TH12-S1 was accomplished. Postoperative radiological parameters revealed good success (LL 40°, SVA 6 cm, PT 19°, TPA 22°, and a Cobb angle of 8°). Improvement of the Oswestry disability index (ODI) of 42 to 18, the visual analog scale (VAS) of 8 to 1, and walking distance 100 to 8000 m compared to preoperatively resulted at 24 months follow-up. The precise coronal and sagittal correction of a rigid degenerative kyphoscoliosis presents a major challenge. Asymmetric PSO is able to realign the thoracolumbar spine in both the coronal and sagittal planes. The creation of an in vitro 3D-printed model of a patient's spinal deformity in combination with a software to calculate the correction angles facilitates preoperative planning and implementation of aPSO.

Transoral vertebroplasty of the lateral mass of C1 using image guidance

BACKGROUND

Osteolytic lesions of the anterior aspects of C1 (lateral mass) are difficult to address in a minimally invasive fashion and are often treated by craniocervical instrumentation.

METHODS

We report the feasibility and technical method of transoral vertebroplasty of the lateral mass of the atlas using image guidance and describe the workflow of the procedure. To our knowledge, there has not yet been a technical description of a transoral vertebroplasty using image guidance.

RESULTS

Adequate positioning of the pedicle access needle using image guidance for addressing the lateral mass of C1 through a transoral, permuceous access can be achieved.

CONCLUSIONS

With the assistance of image guidance, it is safe and feasible to access the lateral mass of the atlas. This constitutes a minimally invasive and fast alternative for introducing the bone needle to C1 rather than using a fluoroscopic device alone.

Serious tumor seeding after brainstem biopsy and its treatment-a case report and review of the literature

Stereotactic brain biopsies for histopathological diagnosis are a common technique in case of intracranial lesions, particularly in those not amenable for resection. Tumor seeding alongside the surgical trajectory after fine-needle aspiration is a known problem in several visceral tumors. Whereas in these cases a complete resection of the biopsy trajectory may later be performed, this strategy is not feasible in stereotactic brain biopsy. We report a case of tumor seeding along the entire biopsy tract after stereotactic biopsy of a brainstem metastasis. A 68-year-old male patient with a concomitantly diagnosed kidney lesion presented with a singular lesion in the brainstem. After confirmation of metastasis by stereotactic biopsy, stereotactic radiosurgery (SRS) was applied. The primary tumor was treated by laparoscopic nephrectomy. Three months after SRS, the patient presented with a secondary clinical deterioration for only a few weeks. The MRI scan showed tumor seeding along the entire biopsy tract. Salvage treatment including hypofractionated stereotactical irradiation and seven cycles of bevacizumab was administered to obtain symptom control. Massive seeding of tumor after stereotactic biopsy accordingly rare, taking into account that stereotactic biopsy is a very common neurosurgical intervention. Nonetheless, we think that the potential risk has to be kept in mind, as it might be neglected.

Cervical arthroplasty with ROTAIO® cervical disc prosthesis: first clinical and radiographic outcome analysis in a multicenter prospective trial

Background

Cervical Disc Arthroplasty (CDA) seems to be an alternative to Anterior Cervical Decompression and Fusion (ACDF) and was developed to minimize the risk of Adjacent Segment Disease (ASD). The ROTAIO Cervical Disc Prosthesis represents a new unconstrained implant with a variable centre of rotation which should enable physiological facet-guided movement. The aim of this current study was to evaluate the clinical outcomes after arthroplasty using ROTAIO Cervical Disc Prosthesis.

Method

Twenty-seven female and 18 male patients (n = 45) with a mean age of 43.7 ± 7.8 years were prospectively followed up for a maximum of 24 month. Clinical outcomes were assessed by Neck Disability Index (NDI), visual analogue scale (VAS) scores for neck and arm pain, patients´ overall satisfaction and the usage of analgesics. Additionally, radiographic information including ROM of the functional spinal unit (FSU) and signs of adjacent segment disease were recorded.

Results

NDI and VAS scores showed significant improvement 6 months after surgery and at last follow-up (p < 0.001). Concerning overall satisfaction 95.7 % of the patients showed good to excellent results at the last visit and a significant reduction of analgesic usage was observed (p < 0.001). Radiographic measurements showed a mean increase of ROM up to 8.40° in the treated FSU at last follow-up (p < 0.001). No signs of anterior migration or dislocation of the prosthesis and no subsidence was recorded radiographically. There were no major complications and a low rate of secondary procedures (2.2 %).

Conclusion

In the 24-months follow-up the ROTAIO Cervical Disc Prosthesis provided excellent clinical and radiographical results and seems to be safe and effective for the treatment of symptomatic single-level degenerative disc disease.

Relative survival of patients with non-malignant central nervous system tumours: a descriptive study by the Austrian Brain Tumour Registry

BACKGROUND

Unlike malignant primary central nervous system (CNS) tumours outcome data on non-malignant CNS tumours are scarce. For patients diagnosed from 1996 to 2002 5-year relative survival of only 85.0% has been reported. We investigated this rate in a contemporary patient cohort to update information on survival.

METHODS

We followed a cohort of 3983 cases within the Austrian Brain Tumour Registry. All patients were newly diagnosed from 2005 to 2010 with a histologically confirmed non-malignant CNS tumour. Vital status, cause of death, and population life tables were obtained by 31 December 2011 to calculate relative survival.

RESULTS

Overall 5-year relative survival was 96.1% (95% CI 95.1-97.1%), being significantly lower in tumours of borderline (90.2%, 87.2-92.7%) than benign behaviour (97.4%, 96.3-98.3%). Benign tumour survival ranged from 86.8 for neurofibroma to 99.7% for Schwannoma; for borderline tumours survival rates varied from 83.2 for haemangiopericytoma to 98.4% for myxopapillary ependymoma. Cause of death was directly attributed to the CNS tumour in 39.6%, followed by other cancer (20.4%) and cardiovascular disease (15.8%).

CONCLUSION

The overall excess mortality in patients with non-malignant CNS tumours is 5.5%, indicating a significant improvement in survival over the last decade. Still, the remaining adverse impact on survival underpins the importance of systematic registration of these tumours.

Rapid wound healing of scalp wounds devoid of periosteum with milling of the outer table and split-thickness skin grafting

BACKGROUND

Excision of large scalp tumours may result in exposed bone devoid of periosteum. The resultant surgical defects may be too large to close by either primary closure or local cutaneous flap. The denuded bone usually precludes the immediate placement of a skin graft.

OBJECTIVES

To describe our experience with milling the outer cortical table of the skull in order to promote granulation and hasten wound healing.

METHODS

In 11 patients, we expanded existing techniques of exposing diploic veins in the cancellous bone by completely milling the exposed outer table of the scalp bone with a rose head burr driven by a pneumatic power drill. After induction of punctate bleeding a split-skin graft was placed in the same session and secured with a tie-over foam dressing. Dressing was removed 7 days after surgery. All patients received perioperative antibiotics. Informed consent was obtained prior to the procedure.

RESULTS

In all 11 patients a healing of the split-thickness skin graft was observed within 1 week.

CONCLUSIONS

The combination of extensive exposure of cancellous bone and an immediate split-thickness skin graft reduces convalescence time from multiple weeks to 7 days. This is beneficial in older patients sparing them from frequent visits to the doctor. Furthermore, early closure may reduce the risk of infection.

Prolonged administration of temozolomide in adult patients with anaplastic glioma

PURPOSE

Prolonged administration of temozolomide is widely used in patients with glioblastoma; whereas the treatment of anaplastic glioma differs between neurooncological centres. The safety, feasibility and efficacy of prolonged temozolomide administration in patients with anaplastic gliomas was evaluated.

PATIENTS AND METHODS

Forty-two patients with primary, recurrent or secondary anaplastic glioma were retrospectively analysed for the course of their disease. Treatment mostly consisted of surgery, followed by radiotherapy with concomitant and adjuvant temozolomide. In five patients with recurrence of primary anaplastic glioma, chemotherapy was initiated without previous surgery. Temozolomide was administered until evidence of tumour recurrence, appearance of serious side-effects or patients' wish to finish chemotherapy.

RESULTS

The median overall survival (OS) was 39 months with a median cycle number of 7.5 (1-42). Treatment with temozolomide was stopped in 12 patients due to side-effects in general, whereas in only three patients (7.1%) treatment had to be discontinued due to haematological side-effects. There was no evidence of treatment related infections or grade IV toxicity. Extent of surgery had a significant influence on OS in anaplastic gliomas, the number of adjuvant temozolomide cycles showed a positive influence as well on time to progression (TTP) and OS.

CONCLUSION

Prolonged administration of adjuvant temozolomide is safe and can be favorable for patients with anaplastic gliomas.

Microembolic signal monitoring after coiling of unruptured cerebral aneurysms: an observational analysis of 123 cases

BACKGROUND AND PURPOSE

Thromboembolic events after aneurysm coiling are common, but the optimal algorithm for emboli prevention remains unclear. MESs correlate with the occurrence of impending ischemic events and may be used for management guidance. This study reports the use of MES monitoring with regard to aneurysm characteristics and coiling technique after a specific anticoagulation protocol.

MATERIALS AND METHODS

We analyzed 123 consecutive, elective endovascular procedures. Patients received intraprocedural and continuous heparin if feasible. Demographic data, aneurysm size, type of intervention/complication, medication, imaging, and clinical outcome were analyzed. MES monitoring was performed in all patients both immediately after as well as >12 hours after the procedure.

RESULTS

Heparinization within the first 12 hours was associated with lower numbers of MESs early after coiling (3.4 versus 18.8 MESs/hr). When on heparin, larger aneurysm size, stent-assisted procedures, or incomplete occlusion did not lead to a significant increase in MESs. If the initial MES count on heparin was >10 MESs/hr, it was always safe to discontinue heparin. Inability to initiate early, continuous heparinization was associated with new neurologic deficits. Additional administration of antiplatelet agents showed lower MES counts initially, but the difference was not significant.

CONCLUSIONS

MES monitoring is a powerful adjunct to monitor efficacy of treatment algorithms for emboli prevention after coiling. In our series, early heparinization was associated with a lower incidence of MESs. This is of particular importance in larger aneurysms, stent-assisted procedures, and incomplete occlusions, in which the thromboembolic risk is greatest early on and antiplatelet treatment alone may not suffice.

Management of patients with low-grade gliomas - a survey among German neurosurgical departments

BACKGROUND AND AIMS OF THE STUDY

The diagnosis and treatment of low-grade gliomas (LGG) are multimodal. Today, there is no defined standard in diagnosis and treatment. Controversies are, in general, about a "wait-and-see" strategy, diagnostic workup, surgical intervention, postoperative imaging, adjuvant treatment, and follow-up. The aim of this study is to gain an overview about management strategies of high-volume German neurosurgical departments treating these patients.

MATERIAL AND METHODS

A questionnaire including diagnostic, preoperative, perioperative, and postoperative parameters and 5 cases with magnetic resonance imaging data with questions to various treatment options in these patients was sent to all 34 German neurosurgical departments at university hospitals.

RESULTS

In total, 24 questionnaires were returned and analysed. Centres were divided into those who generally practice a "wait-and-see" strategy vs. those who do not or only in highly selected cases. Statistical analyses were performed with Fisher test and Chi (2)-test. Interestingly, 50% of all centres routinely follow a "wait-and-see" strategy.

CONCLUSION

Although the management of patients with LGG is complex and a simple questionnaire will not be able to define a standard in diagnosis and treatment, this study offers an overview on strategies at high-volume academic centres dealing with these patients. There is consensus to resect superficially located lobar and circumscribed low-grade lesions. However, the differences between centres become apparent with increasing complexity of the lesions.

Response to temozolomide in supratentorial multifocal recurrence of malignant ependymoma

Intracranial anaplastic ependymomas are a very rare entity within the group of adult CNS neoplasms. Thus, no standard adjuvant therapy after surgical resection has been defined so far. External radiotherapy is commonly administered, but the role of chemotherapy is still unclear in malignant ependymomas. The case of a 25-year-old female patient with multifocal recurrence of a supratentorial malignant ependymoma administered temozolomide as second-line therapy is reported. Currently, 5 months after initiation of temozolomide treatment, there is no evidence of radiographic progression. Temozolomide could constitute a promising approach to supratentorial recurrent and multifocal anaplastic ependymoma of adults.

SOM230 (pasireotide) and temozolomide achieve sustained control of tumour progression and ACTH secretion in pituitary carcinoma with widespread metastases

Pituitary carcinomas are rare and neurosurgically challenging lesions, as they commonly relapse after surgical removal. Their prognosis is dismal due to their limited response to radiotherapy and chemotherapy. In recent studies, temozolomide was administered in very few patients with partial effects. We report a patient with an ACTH-secreting pituitary carcinoma and widespread intracranial, spinal and systemic metastases despite repeated surgical treatment, bilateral adrenalectomy, medical treatment and radiotherapy. Additionally to chemotherapy with temozolomide, the patient received SOM230 as salvage therapy with an improvement of the patient's clinical status, and a reduction of ACTH levels. After 12 months of combination therapy a sustained tumor control was achieved and persisted upon monotherapy with SOM230 for more than 9 months thereafter. Thus, temozolomide in combination with SOM230 seems to be promising in patients with ACTH-secreting metastasized pituitary carcinoma.

Effects of the selective endothelin A (ET(A)) receptor antagonist Clazosentan on cerebral perfusion and cerebral oxygenation following severe subarachnoid hemorrhage - preliminary results from a randomized clinical series

OBJECTIVE

To study the effects of clazosentan, a new selective endothelin receptor subtype A antagonist, on cerebral perfusion and cerebral oxygenation following severe aneurysmal subarachnoid haemorrhage (aSAH).

METHODS

All 12 patients treated at our institution in the context of a phase IIa, multicenter, randomized trial on clazosentan's safety and efficacy in reducing the incidence of angiographic cerebral vasospasm were included in this substudy. The phase IIa study (n = 34) consisted of two parts: a double-blind, randomized Part A (clazosentan 0.2 mg/kg/h versus placebo) and an open-label Part B (clazosentan 0.4 mg/kg/h for 12 h followed by 0.2 mg/kg/h) for patients with established vasospasm. In parallel to the phase IIa study protocol, which included assessment of vasospasm by angiography and transcranial Doppler sonography, we determined regional cerebral blood flow (rCBF), cerebrovascular resistance, and regional tissue oxygenation.

RESULTS

Cerebral perfusion was comparable between treatment groups during the early post-bleeding period (rCBF placebo, 22.6 +/- 3.5 ml/100 g/min versus rCBF clazosentan, 23.9 +/- 1.1 ml/100 g/min). By the time of control angiography (day 8 after aSAH), rCBF decreased by 50% in the placebo group (11.3 +/- 6.7 ml/ 100 g/min) while it remained stable in the clazosentan group (23.5 +/- 12.9 ml/100 g/min). During Part B of the study, all 3 patients who developed haemodynamically relevant vasospasm during placebo treatment, showed a sustained improvement in rCBF upon conversion to clazosentan.

CONCLUSIONS

These preliminary data suggest that clazosentan reduces the extent of vasospasm-associated impairment of cerebral perfusion following aSAH. Furthermore, clazosentan may exert beneficial actions on overt vasospasm-associated hypoperfusion.

Delayed visual deterioration after pituitary surgery--a review introducing the concept of vascular compression of the optic pathways

BACKGROUND

Delayed visual deterioration after pituitary surgery has been attributed to secondary empty sella syndrome and downward herniation of the optic nerves and chiasm, but the pathophysiological basis of this condition is still a matter of debate.

REVIEW

According to the literature, prior radiation therapy, previous visual impairment and transcranial surgery constitute risk factors for delayed visual deterioration. Radiation-induced vascular changes and/or strangulation of the optic nerves or chiasm are thought to compromise local blood flow. Downward herniation of the optic pathways was present in the majority of cases, but did not correlate with visual symptoms and signs, while dense scarring of the chiasm was a reproducable finding in all surgically explored cases. Indentations in the upper margin of the optic nerves or chiasm caused by the A1 segments of the anterior cerebral arteries have been reported repeatedly. As perichiasmal scarring constitutes the most consistent finding, the intimate relationship between artery and nerve with consecutive pulsatile pressure may constitute a causative factor in delayed visual dysfunction after pituitary surgery. The authors therefore introduce the concept of vascular compression, which is illustrated with a personal case of a successful decompression procedure with teflon interposition between the A1 segment and the non-herniated optic nerve to treat visual loss eight months following removal of a hemorrhagic pituitary adenoma.

CONCLUSIONS

Clinicians should be aware that surgical exploration via a transcranial approach is indicated in cases of progressive visual loss late after pituitary surgery, no matter whether downward displacement of the optic pathways is present on imaging studies or not. Special attention should be paid intra-operatively to the dissection of the intimate relationship between the anterior cerebral arteries and the optic nerves and chiasm.

Bilateral meningiomatous lesions of the spinal accessory nerves

BACKGROUND

Meningiomas arising from cranial nerves with no dural attachment are exceedingly rare. The authors present a patient with bilateral meningiomatous lesions originating symmetrically from both spinal accessory nerves.

CASE REPORT

A 61-year old woman presented with a one-year history of spinal ataxia and minimal left-sided motor impairment. Magnetic resonance imaging demonstrated two extrinsic lesions dorsolaterally of the medulla. Surgical exposure via a midline suboccipital approach with C1 laminectomy revealed the lesions arising from the spinal accessory nerves and in direct contact with the vertebral arteries. Histological investigation showed hypocellular fibrous lesions with proliferating meningothelial cells, psammoma bodies and immunoreactivity for vimentin, S-100 protein and epithelial membrane antigen.

INTERPRETATION

To the authors' knowledge this is the first report of intradural tumours of the spinal accessory nerves not derived from Schwann cells and the first report of bilateral intracranial meningiomatous lesions without dural attachment.

Continuous monitoring of regional cerebral blood flow during temporary arterial occlusion in aneurysm surgery

OBJECT

Temporary arterial occlusion (TAO) during aneurysm surgery carries the risk of ischemic sequelae. Because monitoring of regional cerebral blood flow (rCBF) may limit neurological damage, the authors evaluated a novel thermal diffusion (TD) microprobe for use in the continuous and quantitative assessment of rCBF during TAO.

METHODS

Following subcortical implantation of the device at a depth of 20 mm in the middle cerebral artery or anterior cerebral artery territory, rCBF was continuously monitored by TD microprobe (TD-rCBF) throughout surgery in 20 patients harboring anterior circulation aneurysms; 46 occlusive episodes were recorded. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The mean subcortical TD-rCBF decreased from 27.8+/-8.4 ml/100 g/min at baseline to 13.7+/-11.1 ml/100 g/min (p < 0.0001) during TAO. The TD microprobe showed an immediate exponential decline of TD-rCBF on clip placement. On average, 50% of the total decrease was reached after 12 seconds, thus rapidly indicating the severity of hypoperfusion. Following clip removal, TD-rCBF returned to baseline levels after an average interval of 32 seconds, and subsequently demonstrated a transient hyperperfusion to 41.4+/-18.3 ml/l 00 g/min (p < 0.001). The occurrence of postoperative infarction (15%) and the extent of postischemic hyperperfusion correlated with the depth of occlusion-induced ischemia.

CONCLUSIONS

The new TD microprobe provides a sensitive, continuous, and real-time assessment of intraoperative rCBF during TAO. Occlusion-induced ischemia is reliably detected within the 1st minute after clip application. In the future, this may enable the surgeon to alter the surgical strategy early after TAO to prevent ischemic brain injury.

Xenon-induced flow activation in patients with cerebral insult who undergo xenon-enhanced CT blood flow studies

BACKGROUND AND PURPOSE

Stable xenon-enhanced CT ((s)Xe/CT) has gained wide acceptance in the assessment of regional cerebral blood flow (rCBF) in patients with intracranial abnormalities. The aim of this study was to test whether the contrast medium (ie, (s)Xe) itself directly induces relevant changes in rCBF, thereby distorting any valid determination of cerebral perfusion by using (s)Xe/CT.

METHODS

To characterize the degree and temporal dynamics of (s)Xe-induced flow activation, a thermal diffusion (TD)-based microprobe was placed subcortically into the frontal lobe on either hemisphere to assess rCBF (TD-rCBF) continuously in 23 patients (mean age, 55 +/- 18 years) with severe intracranial insult who were undergoing (s)Xe/CT.

RESULTS

In 35, the (s)Xe/CT studies TD-rCBF rose from 25 +/- 17 mL/100 g per minute (range, 5-42 mL/100 g per minute) before (s)Xe administration to 28 +/- 21 mL/100 g per minute (range, 6-46 mL/100 g per minute) after arterial (s)Xe saturation was reached. Analysis of the flow activation curve showed a logarithmic shape with an increase in TD-rCBF between 3% and 7% within the first 76 seconds of (s)Xe wash-in (12% after 190 seconds) and showed no further augmentation until the end of the blood flow study.

CONCLUSION

The observed (s)Xe-induced rCBF activation, which showed significant inter- and intraindividual variability, might lead to overestimation of rCBF in patients with severe intracranial insult. The obtained flow activation curve provides essential information that may allow subsequent refinement of the methodology, aiming to further minimize the influence of (s)Xe-induced rCBF activation on rCBF calculations when using (s)Xe/CT technology.

Pyogenic abscess of the filum terminale. Case report

Intradural spinal abscesses are rare. They are predominantly encountered as intramedullary abscesses of the spinal cord and infrequently as subdural lesions. To their knowledge, the authors report the first case of a chronic pyogenic abscess of the terminal filum in an adult woman with kyphoscoliosis who presented with lumbar radiculopathies. Magnetic resonance imaging revealed a partly cystic intradural L3-4 mass that markedly enhanced after contrast administration. Laboratory signs of infection were absent. Intraoperatively a lobulated lesion observed within the terminal filum was tightly attached to neighboring nerve roots by fibrosis. On opening the cyst wall pus was revealed. Histological examination confirmed the diagnosis of a chronic abscess. Microbiological culture detected Staphylococcus aureus. Antibiotic therapy resulted in an uneventful postoperative course, with complete resolution of symptoms and radiologically demonstrated disappearance of the lesion. The pathogenesis and radiological features of the lesion are discussed. Although extremely rare, a pyogenic abscess should be considered in the differential diagnosis of mass lesions of the cauda equina, especially in patients with preexisting spinal abnormalities. Surgical exposure, including drainage and biopsy sampling to rule out underlying tumor, combined with antibiotic treatment result in a favorable outcome.

Continuous monitoring of regional cerebral blood flow: experimental and clinical validation of a novel thermal diffusion microprobe

OBJECT

Current clinical neuromonitoring techniques lack adequate surveillance of cerebral perfusion. In this article, a novel thermal diffusion (TD) microprobe is evaluated for the continuous and quantitative assessment of intraparenchymal regional cerebral blood flow (rCBF).

METHODS

To characterize the temporal resolution of this new technique, rCBF measured using the TD microprobe (TD-rCBF) was compared with rCBF levels measured by laser Doppler (LD) flowmetry during standardized variations of CBF in a sheep model. For validation of absolute values, the microprobe was implanted subcortically (20 mm below the level of dura) into 16 brain-injured patients, and TD-rCBF was compared with simultaneous rCBF measurements obtained using stable xenon-enhanced computerized tomography scanning (sXe-rCBF). The two techniques were compared using linear regression analysis as well as the Bland and Altman method. Stable TD-rCBF measurements could be obtained throughout all 3- to 5-hour sheep experiments. During hypercapnia, TD-rCBF increased from 49.3+/-15.8 ml/100 g/min (mean +/- standard deviation) to 119.6+/-47.3 ml/100 g/ min, whereas hypocapnia produced a decline in TD-rCBF from 51.2+/-12.8 ml/100 g/min to 39.3+/-5.6 m/100 g/min. Variations in mean arterial blood pressure revealed an intact autoregulation with pressure limits of approximately 65 mm Hg and approximately 170 mm Hg. After cardiac arrest TD-rCBF declined rapidly to 0 ml/100 g/min. The dynamics of changes in TD-rCBF corresponded well to the dynamics of the LD readings. A comparison of TD-rCBF and sXe-rCBF revealed a good correlation (r = 0.89; p < 0.0001) and a mean difference of 1.1+/-5.2 ml/100 g/min between the two techniques.

CONCLUSIONS

The novel TD microprobe provides a sensitive, continuous, and real-time assessment of intraparenchymal rCBF in absolute flow values that are in good agreement with sXe-rCBF measurements. This study provides the basis for the integration of TD-rCBF into multimodal monitoring of patients who are at risk for secondary brain injury.

Effects of 30% stable xenon on regional cerebral blood flow in patients with intracranial pathology

Regional cerebral blood flow was assessed continuously in 22 patients with severe intracranial pathology undergoing xenon-enhanced computed tomography by means of an intraparenchymal thermodiffusion based microprobe. Thirty-four blood flow studies were analysed revealing an overall xenon-induced flow activation from about 12%. Regional CBF rose from 25 +/- 17 ml/100 g/min (mean +/- sd; range: 5.2-41.8 ml/100 g/min) before xenon administration to 28 +/- 21 ml/100 g/min (p = 0.012; range: 6.5-46.4 ml/100 g/min) when "steady-state" during xenon "wash-in" was reached. Flow activation curve demonstrated a logarithmic shape with an increase in rCBF between 3% and 7% within the first 90 seconds of xenon "wash-in", 12% after 160 seconds, and showed no further augmentation until the end of the blood flow study after 310 seconds. It is concluded that xenon inhalation leads to flow augmentation in patients with cerebral insult, which does not exceed flow activation obtained in normal subjects. The impact of the results on xenon-enhanced computed tomography cerebral blood flow calculations remains to be established.