Qualitative Assessment of Titanium versus Carbon Fiber/Polyetheretherketone Pedicle Screw-Related Artifacts: A Cadaveric Study.

BACKGROUND: Dorsal instrumentation and decompression are the mainstays of spinal tumor treatment. Replacing titanium screws with carbon fiber-reinforced polyetheretherketone (CFRP) screws can reduce imaging artifacts on neural structures and perturbations of radiation dose. Further reduction of metal content in such screws might enhance the benefit. The aim of this study was to assess the artifacts produced by all-titanium screws (Ti-Ti), CFRP thread-titanium screw heads (C-Ti), and all-CFRP screws (C-C). METHODS: A cadaveric spine was used to place Ti-Ti, C-Ti, and C-C consecutively from T2 to S1. Computed tomography and 1.5T and 3T magnetic resonance imaging were performed for each screw system. Axial T1- and T2-weighted sequences of representative thoracic and lumbar regions were assessed for artifacts. The artifacts were classified as not relevant, considerable, or severe. RESULTS: We evaluated 92 screws and made 178 artifact assessments. The artifacts were clearly visible in computed tomography scans but did not influence the visualization of intraspinal structures. Severe magnetic resonance imaging artifacts were found in 28% (17/60, mostly in the thoracic spine) of Ti-Ti, 2% (1/60, all T1 sequences) of C-Ti, and 0% of C-C, and considerable artifacts were found in 47% (28/60) of Ti-Ti, 10% (6/60, only 1 T2 sequence) of C-Ti, and 0% of C-C screws (P < 0.001). CONCLUSIONS: CFRP pedicle screws reduced the artifact intensity in spinal structures compared with titanium screws, and may be beneficial for planning radiotherapy and for follow-up imaging. C-C demonstrated an enhanced effect on dorsal structures.

Quantitative assessment and localization of the hollowing of the temple after craniectomy and cranioplasty-The frontozygomatic shadow.

BACKGROUND: After cranioplasty, in many cases a not negligible soft tissue defect remains in the temporozygomatical area, also referred to as a hollowing defect of the temple. OBJECTIVE: To assess the precise localization and volume of the hollowing defect, to optimize future cranioplasties. METHODS: CT data of patients who received craniectomy and conventional CAD cranioplasty in our institution between 2012 and 2018 were analyzed. CT datasets prior to craniectomy and after cranioplasty were subtracted to quantify the volume and localization of the defect. RESULTS: Out of 91 patients, 21 had suitable datasets. Five cases had good cosmetic results with no defect visible, 16 patients had an apparent hollowing defect. Their average defect volume was 5.0 cm3 ± 4.5 cm3. The defect localizations were in the area behind the zygomatic process and just below the superior temporal line, covering an area of app. 3x3 cm2. Surgical attempts of temporal muscle restoration were more often found in reports of good results (p<0.01), but also in 50% of reports, whose surgeries resulted in hollowing of the temple. Mean time between the two surgeries was 112 ± 43 days. No significant differences between patients with and without hollowing defect were detected regarding time between the two surgeries, age or performing surgeon. CONCLUSION: This work supplies evidence for the indication of a surgical corrective during cranioplasty in the small but cosmetically relevant area of the "frontozygomatic shadow". Based on our 3D data analysis, future focused surgical strategies may obtain better aesthetical results here.

Towards the targeted assessment of relevant problems: Optimization of the distress Thermometer for adult neuro-oncological patients.

OBJECTIVE: Generic psychosocial screening tools may not reflect the unique symptom profile of brain tumour patients (BTPs). The aim was to adapt the problem list of the distress thermometer (DT) for BTPs. METHODS: First, items of low relevance for BTPs were identified on basis of retrospective analyses. Second, relevant yet missing problems were identified via an extensive literature search, qualitative interviews with BTPs and experts, as well as an online expert survey. The resulting raw version of the adapted problem list in BTPs was subsequently pretested. RESULTS: In the first part, data of n = 657 BTPs were analysed. Twelve items (20%) were excluded in this step as they proved to be less relevant for BTPs (i.e., items were endorsed by less than 10% and without significant correlations to patients' DT score). In the second part, qualitative interviews and the online survey with 102 professionals led to the addition of 21 new and the modification and condensation of 17 relevant problems specific for BTPs. This adapted list was than successfully pretested in n = 19 patients, leading to the 'distress thermometer brain tumour problem list' (DT-BT), consisting of 42 relevant problems. CONCLUSION: The adapted problem list for the DT particularly reflects the neurological and psychosocial burden of an intracranial tumour and allows for the targeted assessment of the specific burdens and needs of BTPs. Our revised version of the DTs problem list (DT-BT) should in the next step be widely validated in multinational samples.

Comprehensive Anatomic Assessment of Ipsilateral Pterional Versus Contralateral Subfrontal Approaches to the Internal Carotid Ophthalmic Segment: A Cadaveric Study and Three-Dimensional Simulation.

OBJECTIVE: Medially pointing aneurysms of the ophthalmic segment of the internal carotid artery (oICA) represent a neurosurgical challenge. Conventional ipsilateral approaches require internal carotid artery and optic nerve (ON) mobilization as well as anterior clinoidectomy (AC), all associated with increased surgical risk. Contralateral approaches could provide a better exposure of the superomedial aspect of the oICA, ophthalmic artery, and superior hypophyseal artery, sparing AC and internal carotid artery or ON mobilization. However, the microsurgical anatomy of this approach has not been systematically studied. In the present work, we exhaustibly analyzed the anatomic and morphometric characteristics of contralateral approaches to the oICA and compared them with those from ipsilateral approaches. METHODS: We assessed 36 ipsilateral and contralateral approaches to the oICAs in cadaveric specimens and live patients, using for the latter a three-dimensional virtual reality (VR) system. RESULTS: Contralateral approaches spared sylvian fissure dissection and required only minimal frontal lobe retraction. The ipsilateral and contralateral oICA were found at a depth of 49.2 ± 1.8 mm (VR, 50.1 ± 2.92 mm) and 65.1 ± 1.5 mm (VR, 66.05 ± 3.364 mm) respectively. The exposure of the superomedial aspect of oICA was 7.25 ± 0.86 mm (VR: 6 ± 1 mm) contralaterally without ON mobilization and 2.44 ± 0.51 mm (VR, 2 ± 1 mm) ipsilaterally even after AC. Statistical analysis showed that, for nonprefixed chiasm, contralateral approaches achieved a significantly higher exposure of the ophthalmic artery, superior hypophyseal artery, and the superomedial aspect of the oICA with its perforating branches (all P < 0.01). CONCLUSIONS: Contralateral approaches may enable successful exposure of the oICA and related vascular structures, reducing the need for AC or ON mobilization. Systematic clinical/surgical studies are needed to further determine the effectiveness and safety of the approach.

Counseling Patients with a Glioblastoma Amenable Only for Subtotal Resection: Results of a Multicenter Retrospective Assessment of Survival and Neurologic Outcome.

BACKGROUND: Patients with a glioblastoma (GB) amenable only for subtotal resection (STR) represent a challenge in patient counseling. Our objective was to assess impact of extent of resection (EoR) on survival and clinical outcome of these patients. METHODS: We performed a retrospective multicenter assessment. Patients receiving an intended STR in 3 centers with unilocular, primary, highly eloquent GB who received the same adjuvant treatment were included. We assessed EoR, neurologic outcome, and rate of complications. Progression-free survival (PFS) and overall survival (OS) were calculated with Kaplan-Meier estimations. We used 1% EoR and 1-cm3 steps to detect a threshold for a minimal EoR and residual tumor volume (RV) to be beneficial for survival and performed multivariate Cox regression models to assess its influence on PFS and OS. RESULTS: In total, 67 patients were included. EoR and RV were not significantly associated with PFS in multivariate Cox regression. Multivariate Cox regression model for OS revealed that volumetric EoR is a significant predictor for OS (P = 0.002, OR 0.982), same as RV (P = 0.007, OR 1.03), controlling for age, preoperative tumor volume, sex, and recurrent surgery. We found a significant benefit for OS if an EoR >60% or a RV <8 cm3 was reached. In the aforementioned multivariate Cox regression models, an EoR ≤60% and a RV ≥8 cm3 independently showed a significantly negative association with OS (P = 0.044, OR 1.96/P = 0.024, OR 2.07). CONCLUSIONS: In highly eloquent GB, EoR significantly matters for patients' OS. Also, potential RV should be considered when treating these patients. In cases with an expected RV above or an EoR below the aforementioned thresholds, open surgery should be carefully considered.

Patient reported feasibility and acceptance of Montreal Cognitive Assessment (MoCA) screening pre- and postoperatively in brain tumour patients.

BACKGROUND: Montreal Cognitive Assessment (MoCA) represents a short screening tool for neuropsychological deficits. The study's aim was to test feasibility and acceptance of MoCA in patients with brain tumours perioperatively. METHODS: Patients with supratentorial located brain tumours were assessed preoperatively (t1, day -1) and postoperatively (t2, day 3-5) using EORTC-QLQ-C30 + BN20, Distress Thermometer (DT) and the MoCA test (different versions). Feasibility was evaluated by a feedback form and patients were asked about perceived discomfort, overstraining or complexity of MoCA. Results of MoCA were correlated with clinical factors. RESULTS: 63 patients participated, 19 were male. Mean age was 56 years. Mean completion time of MoCA was 11 min (both t1 and t2). At t1, in 27% "moderate or major difficulties" occurred during MoCA assessment vs. 41% at t2. Most of the patients (t1, 93% vs. t2, 86%) negated to be overstrained by MoCA. Better "physical function" according to EORTC-QLQ-C30 (p = 0.041, Pearson = 0.321) and higher KPS (p = 0.012, Pearson = 0.578) correlated to higher MoCA scores. Higher distress at t2 was found to be correlated with a stronger deterioration of MoCA at t2 vs. t1 (p = 0.03, Spearman-Rho = .695). CONCLUSION: The MoCA test was well accepted by the patients and implementable in clinical routine. Further investigations evaluating the sensitivity and specificity of the test in brain tumour patients are required.

Compliance with patient-reported outcome assessment in glioma patients: predictors for drop out.

BACKGROUND: Patient-reported outcomes are of high importance in clinical neuro-oncology. However, assessment is still suboptimal. We aimed at exploring factors associated with the probability for a) drop out of study and b) death during follow-up. METHODS: Patients were assessed twice during follow-up visits scheduled within 3 to 5 months of each other by using 3 validated patient-reported outcome measures (t1: first assessment, t2: second assessment). As "death" was seen as a competing risk for drop out, univariate competing risk Cox regression models were applied to explore factors associated with dropping out (age, gender, WHO grade, living situation, recurrent surgery, Karnofsky Performance Status, time since diagnosis, and patient-reported outcomes assessed by Distress Thermometer, EORTC-QLQ-C30, EORTC-QLQ-BN20, and SCNS-SF-34G). RESULTS: Two hundred forty-six patients were eligible, 173 (70%) participated. Patients declining participation were diagnosed with glioblastomas more often than with other gliomas (56% vs 39%). At t2, 32 (18%) patients dropped out, n = 14 death-related, n = 18 for other reasons. Motor dysfunction (EORTC-QLQ-BN20) was associated with higher risk for non-death-related drop out (HR: 1.02; 95% CI, 1.00-1.03; P = .03). Death-related drop out was associated with age (HR: 1.09; 95% CI, 1.03-1.14; P = .002), Karnofsky Performance Status (HR: 0.92; 95% CI, 0.88-0.96; P < .001), lower physical functioning (EORTC-QLQ-C30; HR: 0.98; 95% CI, 0.96-1.00; P = .04) and lower motor functioning (EORTC-QLQ-BN20; HR: 1.020; 95% CI, 1.00-1.04; P = .02). CONCLUSION: Patients with motor dysfunction and poorer clinical condition seem to be more likely to drop out of studies applying patient-reported outcome measures. This should be taken into account when planning studies assessing glioma patients and for interpretation of results of patient-reported outcome assessments in clinical routine.

Evaluation of surgical decision making and resulting outcome in patients with highly eloquent glioblastoma: Results of a multicenter assessment.

INTRODUCTION: Treatment of glioblastoma(GB) patients amenable only for a subtotal resection(STR) is controversial. Since outcome of patients is affected by surgical management, our aim was to assess surgical decision making and resulting outcome in patients with highly eloquent GBs. PATIENTS AND METHODS: We retrospectively assessed GB patients with intended sub-total resection (STR) or stereotactic biopsy (STX) of 3 neurooncological centers operated between 2008 and 2013. A volumetric assessment of overall extent of resection(oEoR), presence of complications, new permanent neurological deficits(nPNDs) was performed. A central reviewer reassessed all cases blinded and gave recommendation on surgical management and on a potential EoR(pEoR) based on imaging data. We compared outcome data using Mann-Whitney-U-test and Sign-Rank-Test. Survival was assessed based on Kaplan-Meier-estimates. RESULTS: 97 patients were included. In 17 patients received STX, 70 patients a STR and 10 patients a near total resection (NTR, EoR>95%). Median OS was significantly different from STX patients only if NTR was reached (16 vs. 7 months, p=0.042). The central reviewer recommended a more aggressive strategy(NTR or STR resp.) in 41 patients and a less aggressive strategy in 13 patients. Overall, management recommendation was significantly different to clinical treatment (p<0.001). Mean pEoR was significantly higher than oEoR (85.7% vs. 71.3%, p=0.001). Regarding the different OR subgroups, no significant differences were found in the NTR group(12/13 ties, p=1) and in STX group (14/17 ties, p=0.125). In STR group, a significant difference was found (p=0.001). In 38/69 patients a NTR and in 13/77 patients a STX was recommended. CONCLUSION: Surgery in GB patients with intended STR requires precise preoperative planning since potential EoR is mainly underestimated. Especially, patients with lesions amenable for a NTR should not be missed.

Factors associated with supportive care needs in glioma patients in the neuro-oncological outpatient setting.

Objective of this study aimed at assessing glioma patients' supportive care needs in a neurosurgical outpatient setting and identifying factors that are associated with needs for support. In three neuro-oncological outpatient departments, glioma patients were assessed for their psychosocial needs using the Supportive Care Needs Survey short-form (SCNS-SF34-G). Associations between clinical, sociodemographic, treatment related factors as well as distress (measured with the distress thermometer) and supportive care needs were explored using multivariable general linear models. One-hundred and seventy three of 244 eligible glioma patients participated, most of them with primary diagnoses of a high-grade glioma (81%). Highest need for support was observed in 'psychological needs' (median 17.5, range 5-45) followed by 'physical and daily living needs' (median 12.5, range 0-25) and 'health system and information needs' (median 11.3, range 0-36). Needs in the psychological area were associated with distress (R2 = 0.36) but not with age, sex, Karnofsky performance status (KPS), extend of resection, currently undergoing chemotherapy and whether guidance during assessment was offered. Regarding 'health system and information needs', we observed associations with distress, age, currently undergoing chemotherapy and guidance (R2 = 0.31). In the domain 'physical and daily living needs' we found associations with KPS, residual tumor, as well as with distress (R2 = 0.37). Glioma patients in neuro-oncological departments report unmet supportive care needs, especially in the psychological domain. Distress is the factor most consistently associated with unmet needs requiring support and could serve as indicator for clinical neuro-oncologists to initiate support.

Vertebral artery injury during foraminal decompression in "low-risk" cervical spine surgery: incidence and management.

OBJECTIVES: Vertebral artery injury (VAI) during foraminal decompression in cervical spine surgery in the absence of repositioning or screw stabilization is rare. Without immediate recognition and treatment, it may have disastrous consequences. We aimed to describe the incidence and management of iatrogenic VAI in low-risk cervical spine surgery. MATERIALS AND METHODS: The records of all patients who underwent surgical procedures of the cervical spine between January 2007 and May 2012 were retrospectively consecutively evaluated. Anterior cervical discectomy and fusion or arthroplasty as well as dorsal foraminal decompression through the Frykholm approach in degenerative diseases were defined as low-risk surgeries (n = 992). RESULTS: VAI occurred in 0.3 % (n = 3) of 992 procedures: in one case during a dorsal foraminal decompression, and in two cases during the anterior cervical discectomy and fusion (ACDF) of two or four levels, respectively. In the first case, the VAI was intraoperatively misdiagnosed. Despite an initially uneventful course, the patient suffered hemorrhage from a pseudoaneurysm of the injured VA 1 month after surgery. The aneurysm was successfully occluded by endovascular coiling. In both ACDF cases, angiography and endovascular stenting of the lacerated segment proceeded immediately after the surgery. All three patients suffered no permanent deterioration. CONCLUSIONS: In a high-volume surgical center, the incidence of VAI during low-risk cervical spine surgery is extremely low, comprising 0.3 % of all cases. The major risks are delayed sequels of the vessel wall laceration. In cases of VAI, immediate angiographic diagnostics and generous indications for endovascular treatment are obligatory.

Cost of illness in subarachnoid hemorrhage: a German longitudinal study.

BACKGROUND AND PURPOSE: Aneurysmal subarachnoid hemorrhage (SAH) is a cerebrovascular disease with a high mortality rate and severe disability. Longitudinal studies investigating health-economic costs in SAH are scare and only one of them analyzed cost-driving factors. The objective was to evaluate first-year costs in German patients with aneurysmal SAH and to identify independent determinants of costs. METHODS: One hundred thirteen incident cases of aneurysmal SAH treated in the Department of Neurosurgery and Neuroradiology at the University of Bonn (catchment area of 500,000 people) between January 2004 and December 2005 were eligible for the study. Cost data were collected using health-economic questionnaires applied at baseline and 6- and 12-month follow-up time. All costs are expressed in (year 2009 values). Clinical assessments were performed using Hunt and Hess scale, Barthel Index, and Rankin Scale. Independent cost-driving factors were determined using multiple regression analysis. RESULTS: The total first-year costs were 38,300 (95% CI, 34 490 to 43,100) per patient. Direct costs accounted for 58.7% of total costs and were mainly paid by the health insurance (92.0%). Inpatient costs were the main cost component of direct and total costs (42.8% of total costs). The major cost-driving factors of total costs were younger age and worse functional outcome at 12-month follow-up (Barthel Index). CONCLUSIONS: Aneurysmal SAH is a cerebrovascular disease with considerable health-economic burden. Healthcare programs aimed at reducing the burden of SAH on society and individuals should consider cost-driving factors of SAH. Further health-economic studies investigating cost-driving factors of SAH in different countries are needed.

VarioGuide: a new frameless image-guided stereotactic system--accuracy study and clinical assessment.

OBJECTIVE: VarioGuide (BrainLAB AG, Feldkirchen, Germany) is a new system for frameless image-guided stereotaxy. In the present study, we aimed to assess target point accuracy in a laboratory setting and the clinical feasibility of the system. METHODS: Using the phantom of our frame-based stereotactic system (Riechert-Mundinger; Inomed Medizintechnik GmbH, Teningen, Germany), target points were approached from different angles with the frameless system. Target point deviation in the x, y, and z planes was assessed. Furthermore, patients harboring intracranial lesions were diagnostically biopsied using VarioGuide. RESULTS: Phantom-based accuracy measurements yielded a mean target point deviation of 0.7 mm. Between February 2007 and April 2008, 27 patients were diagnostically biopsied. Lesion volumes ranged from 0.2 to 117.6 cm3, trajectory length ranged from 25.3 to 64.1 mm, and the diagnostic yield was 93%. CONCLUSION: Concluding from the phantom measurements with ideal image-object registration, assumed spherical lesions with a volume of 0.524 cm can be biopsied with 100% target localization. Early clinical data revealed VarioGuide to be safe and accurate for lesions of 0.2 cm3 and larger. Thereby, the system seems feasible for the biopsy of most intracranial lesions.