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OBJECTIVE Decision-making for intracranial tumor surgery requires balancing the oncological benefit against the risk for resection-related impairment. Risk estimates are commonly based on subjective experience and generalized numbers from the literature, but even experienced surgeons overestimate functional outcome after surgery. Today, there is no reliable and objective way to preoperatively predict an individual patient’s risk of experiencing any functional impairment. METHODS The authors developed a prediction model for functional impairment at 3 to 6 months after microsurgical resection, defined as a decrease in Karnofsky Performance Status of ≥ 10 points. Two prospective registries in Switzerland and Italy were used for development. External validation was performed in 7 cohorts from Sweden, Norway, Germany, Austria, and the Netherlands. Age, sex, prior surgery, tumor histology and maximum diameter, expected major brain vessel or cranial nerve manipulation, resection in eloquent areas and the posterior fossa, and surgical approach were recorded. Discrimination and calibration metrics were evaluated. RESULTS In the development (2437 patients, 48.2% male; mean age ± SD: 55 ± 15 years) and external validation (2427 patients, 42.4% male; mean age ± SD: 58 ± 13 years) cohorts, functional impairment rates were 21.5% and 28.5%, respectively. In the development cohort, area under the curve (AUC) values of 0.72 (95% CI 0.69–0.74) were observed. In the pooled external validation cohort, the AUC was 0.72 (95% CI 0.69–0.74), confirming generalizability. Calibration plots indicated fair calibration in both cohorts. The tool has been incorporated into a web-based application available at https://neurosurgery.shinyapps.io/impairment/. CONCLUSIONS Functional impairment after intracranial tumor surgery remains extraordinarily difficult to predict, although machine learning can help quantify risk. This externally validated prediction tool can serve as the basis for case-by-case discussions and risk-to-benefit estimation of surgical treatment in the individual patient.

Introduction A subpopulation of patients with hydrocephalus and idiopathic intracranial hypertension (IIH) treated for elevated intracranial pressure (ICP) with a cerebrospinal fluid (CSF) shunt may continue to suffer from symptoms or develop new symptoms despite valve adjustments. The use of telemetric ICP measurements may help confirm a clinical suspicion of CSF under- or overdrainage in these patients. However, point in time, duration and activity during the measurements, which may influence the results, have never been standardized. We devised a simple and repeatable maneuver for outpatient telemetric ICP recording. The aim of this study is to evaluate its test-retest reliability. Methods Data of patients who underwent ventriculoperitoneal or ventriculoatrial shunt placement and subsequent telemetric ICP sensor implantation were retrospectively reviewed. Telemetric ICP recordings in these patients were conducted in a standardized manner: The standing-supine-sitting-paradigm requires postural changes in 10-minute intervals over 30 minutes. First, the patient is requested to walk (upright body position), secondly to lay down (supine body position), and lastly to sit down with a headrest elevation of 60°. All ICP measurements were analyzed using a dedicated freeware tool developed by the first author ( www.icp-analyzer.org ). ICP data were given as mean values (SD) in mmHg. Test-retest validity was assessed using Pearson´s correlation analysis. Results We evaluated 66 ICP data sets obtained repeatedly with a time difference of at least 24 hours under condition of unchanged valve settings in seven patients (1 male, 6 female). Implantation diagnoses were IIH (n=2), congenital hydrocephalus (n=2), normal pressure hydrocephalus (NPH) (n=1) and malresorptive hydrocephalus (n=2). Overall test re-test reliability was excellent (Pearsons correlation coefficient 0.99, p Conclusions We confirmed the high test-retest reliability of the standing-supine-sitting-paradigm for telemetric ICP measurements in the outpatient setting. The high test-retest reliability should be considered as pre-requisite for clinical decision making. We advocate the implementation and further testing of this method to validate its utility in guiding treatment decisions.

BACKGROUND AND PURPOSE Aneurysms of the posterior inferior cerebellar artery (PICA) are relatively uncommon and evidence is sparse about patients presenting with ruptured PICA aneurysms. We performed an analysis of the Swiss SOS national registry to describe clinical presentation, treatment pattern, and neurological outcome of patients with ruptured PICA aneurysms compared with other ruptured posterior circulation (PC) aneurysms. METHODS This was a retrospective analysis of anonymized data from the Swiss SOS registry (Swiss Study on Aneurysmal Subarachnoid Hemorrhage; 2009-2014). Patients with ruptured PC aneurysms were subdivided into a PICA and non-PICA group. Clinical, radiological, and treatment-related variables were identified, and their impact on the neurological outcome was determined in terms of modified Rankin score at discharge and at 1 year of follow-up for the two groups. RESULTS Data from 1864 aneurysmal subarachnoid hemorrhage patients were reviewed. There were 264 patients with a ruptured PC aneurysm. Seventy-four PICA aneurysms represented 28% of the series; clinical and radiological characteristics at admission were comparable between the PICA and non-PICA group. Surgical treatment was accomplished in 28% of patients in the PICA group and in the 4.8% of patients in the non-PICA group. No statistically significant difference was found between the two groups in terms of complications after treatment. Hydrocephalus requiring definitive shunt was needed in 21.6% of PICA patients (p = 0.6); cranial nerve deficit was present in average a quarter of the patients in both PICA and non-PICA group with no statistical difference (p = 0.3). A more favorable outcome (66.2%) was reported in the PICA group at discharge (p

Brain metastases (BMs) are the most frequent malignancy of the central nervous system. Previous research suggested that some metastases show infiltrative behavior rather than sharp demarcation. We hypothesized that three magnetic resonance (MR) imaging parameters—(a) tumor size, (b) extent of peritumoral edema, and (c) presence of multiple BMs—are predictors of cellular invasion beyond the surgically identifiable tumor margins. We performed a post hoc analysis on prospectively collected data of patients with BMs. Biopsies beyond the resection margin and immunohistochemistry were performed to assess infiltration status. The three MR imaging parameters were dichotomized into diameters ≤ 30 mm (“small”) and > 30 mm (“large”), amount of peritumoral edema “extended” and “limited,” and “multiple BMs” and “single BMs,” respectively. The association between infiltration status and imaging parameters was calculated using chi-square test. Biopsy beyond the resection margin was performed in 77 patients; 49 (63.6%) had supramarginal infiltration and 28 patients (36.4%) showed no infiltration. Histological evidence of tumor infiltration was found in 25/41 patients with smaller lesions (61%) and in 24/36 with larger lesions (66.7%, p = 0.64), in 28/44 patients with limited (63.6%) and in 21/33 patients with extended edema (63.6%, p = 1.0), in 28/45 patients (62.2%) with single BM and in 21/32 patients (65.6%) with multiple BMs (p = 0.81). Based on the post hoc analysis of our prospective trial data, we could not confirm the hypothesis that infiltration of brain parenchyma beyond the glial pseudocapsule is associated with the MR imaging parameters tumor size, extent of edema, or multiplicity of metastases.

BACKGROUND Current prognostic tools in aneurysmal subarachnoid hemorrhage (aSAH) are constrained by being primarily based on patient and disease characteristics on admission. OBJECTIVE To develop and validate a complication- and treatment-aware outcome prediction tool in aSAH. METHODS This cohort study included data from an ongoing prospective nationwide multicenter registry on all aSAH patients in Switzerland (Swiss SOS [Swiss Study on aSAH]; 2009-2015). We trained supervised machine learning algorithms to predict a binary outcome at discharge (modified Rankin scale [mRS] ≤ 3: favorable; mRS 4-6: unfavorable). Clinical and radiological variables on admission ("Early" Model) as well as additional variables regarding secondary complications and disease management ("Late" Model) were used. Performance of both models was assessed by classification performance metrics on an out-of-sample test dataset. RESULTS Favorable functional outcome at discharge was observed in 1156 (62.0%) of 1866 patients. Both models scored a high accuracy of 75% to 76% on the test set. The "Late" outcome model outperformed the "Early" model with an area under the receiver operator characteristics curve (AUC) of 0.85 vs 0.79, corresponding to a specificity of 0.81 vs 0.70 and a sensitivity of 0.71 vs 0.79, respectively. CONCLUSION Both machine learning models show good discrimination and calibration confirmed on application to an internal test dataset of patients with a wide range of disease severity treated in different institutions within a nationwide registry. Our study indicates that the inclusion of variables reflecting the clinical course of the patient may lead to outcome predictions with superior predictive power compared to a model based on admission data only.

Background and Purpose: The purpose of this study was to assess nationwide incidence and outcomes of aneurysmal subarachnoid hemorrhage (aSAH). The Swiss SOS (Swiss Study on Subarachnoid Hemorrhage) was established in 2008 and offers the unique opportunity to provide this data from the point of care on a nationwide level. Methods: All patients with confirmed aneurysmal subarachnoid hemorrhage admitted between January 1, 2009 and December 31, 2014, within Switzerland were recorded in a prospective registry. Incidence rates were calculated based on time-matched population data. Admission parameters and outcomes at discharge and at 1 year were recorded. Results: We recorded data of 1787 consecutive patients. The incidence of aneurysmal subarachnoid hemorrhage in Switzerland was 3.7 per 100 000 persons/y. The number of female patients was 1170 (65.5%). With a follow-up rate of 91.3% at 1 year, 1042 patients (58.8%) led an independent life according to the modified Rankin Scale (0–2). About 1 in 10 patients survived in a dependent state (modified Rankin Scale, 3–5; n=185; 10.4%). Case fatality was 20.1% (n=356) at discharge and 22.1% (n=391) after 1 year. Conclusions: The current incidence of aneurysmal subarachnoid hemorrhage in Switzerland is lower than expected and an indication of a global trend toward decreasing admissions for ruptured intracranial aneurysms. Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03245866.

Introduction The postoperative functional status of patients with intracranial tumors is influenced by patient-specific factors, including age. Research question This study aimed to elucidate the association between age and postoperative morbidity or mortality following the resection of brain tumors. Material and methods A multicenter database was retrospectively reviewed. Functional status was assessed before and 3–6 months after tumor resection by the Karnofsky Performance Scale (KPS). Uni- and multivariable linear regression were used to estimate the association of age with postoperative change in KPS. Logistic regression models for a ≥10-point decline in KPS or mortality were built for patients ≥75 years. Results The total sample of 4864 patients had a mean age of 56.4 ​± ​14.4 years. The mean change in pre-to postoperative KPS was −1.43. For each 1-year increase in patient age, the adjusted change in postoperative KPS was −0.11 (95% CI -0.14 - - 0.07). In multivariable analysis, patients ≥75 years had an odds ratio of 1.51 to experience postoperative functional decline (95%CI 1.21–1.88) and an odds ratio of 2.04 to die (95%CI 1.33–3.13), compared to younger patients. Discussion Patients with intracranial tumors treated surgically showed a minor decline in their postoperative functional status. Age was associated with this decline in function, but only to a small extent. Conclusion Patients ≥75 years were more likely to experience a clinically meaningful decline in function and about two times as likely to die within the first 6 months after surgery, compared to younger patients.

Background Metastatic brain disease continues to have a dismal prognosis. Previous studies achieved a reduction of local recurrence rates by aggressively resecting the peritumoral zone (supramarginal resection) or using 5-aminolaevulinic acid (5-ALA) fluorescence. The aim of the present study is to assess whether the use of 5-ALA has an impact on local recurrence or survival compared to conventional white light microscopic tumor resection. Materials and methods We included consecutive patients who underwent surgical resection of brain metastases. Two groups were compared: In the "white light" group, resection was performed with conventional microscopy. In the 5-ALA group, fluorescence guided peritumoral resection was additionally performed after standard microscopic resection. In-brain recurrence and mortality were compared between groups. Results N = 175 patients were included in the study. All baseline parameters were similarly distributed with no significant difference between surgical groups. Local in-brain recurrence occurred in 21/175 patients (12%) with a rate of 15/119 (12.6%) in the white light and 6/56 (10.7%) in the 5-ALA group (p = 0.720). The use of 5-ALA influenced neither in-brain recurrence (OR 0.59 [CI = 95% 0.18; 1.99], p = 0.40) nor mortality (OR 0.71 [CI = 95% 0.27; 1.85], p = 0.49). Conclusions The use of 5-ALA did not result in lower in-brain recurrence or mortality compared to the use of white light microscopy. The most prominent predictors of survival remain favorable preoperative performance status, a low tumor diameter and the absence of multiple cerebral lesions.

Unresectable malignant intramedullary tumors and metastases usually require radiotherapy which intensifies spinal cord edema and might result in neurological decline. Spinal expansion duroplasty before radiotherapy enlarges the intrathecal volume and might thus prevent neurological deficits. The study aims to evaluate the clinical course of patients undergoing expansion duroplasty. This retrospective analysis (2007-2016) included all patients with unresectable intramedullary tumors who underwent spinal expansion duroplasty. To assess the degree of preoperative cord enlargement, we calculated the "diameter ratio": diameter of the spinal cord below and above the tumor / diameter of the tumor × 2. The presence of perimedullary cerebrospinal fluid (CSF) at the affected levels was analyzed on the preoperative magnetic resonance imaging (MRI). We recorded the occurrence of neurological deficits, wound breakdown, and CSF fistula. We screened 985 patients, 11 of which were included. Eight patients had an intramedullary metastasis, three patients a spinal malignant glioma. A diameter ratio ≤ 0.8 representing a significant preoperative intramedullary enlargement was seen in 10 cases (90.9%). Postoperative imaging was available in 9 patients, demonstrating successful decompression in 8 of the 9 patients (88.9%). The postoperative course was uneventful in 9 patients (81.8%). Mean overall survival was 13.4 (SD 16.2) months. Spinal expansion duroplasty prior to radiotherapy is a previously undescribed concept. Despite neoadjuvant radiation, no wound breakdown or CSF fistula occurred. In unresectable intramedullary tumors and metastases, spinal expansion duroplasty seems to be a safe procedure with the potential to prevent neurological decline due to radiation-induced cord swelling.

It was suggested that D, L-Methadone might improve the clinical course of glioma patients. Owing to massive press coverage, patients demand the prescription of D, L-Methadone, but regarding its adjunctive use in glioma therapy there is no standard medication plan. Furthermore, it is not known which side effects the administration of D, L-Methadone might harbor, especially if the patients are opioid-naive and if D, L-Methadone therapy was managed by the patients themselves or their general practitioners. Opioid-naive patients with high-grade glioma (new diagnosis or recurrent) receiving D, L-Methadone were included in this retrospective observational analysis. Side effects were assigned if the condition deteriorated in conjunction with the initiation of D, L-Methadone and resolved/ ameliorated after cessation of the intake/reduction of the dosage. Side effects were categorized according to the common toxicity criteria (CTC). Twenty-four patients were included. All patients were opioid-naive and received D, L-Methadone from their general practitioners. Sixteen patients experienced side effects. The median dosage when side effects began to occur was 15.8 mg/ 24 h. Fatigue and mood changes were reported most frequently (14 of 24 patients). Five patients had severe side effects related to relatively high doses. In all cases, symptoms resolved after cessation or dose reduction. Our results show that D/L M intake lead to frequent occurrence of side effects in opioid-naive patients especially when not handled with caution and close supervision. Patients, their relatives, their GPs and neuro-oncologists need to be informed about the broad spectrum of side effects in order to thoroughly counsel glioma patients.

IntroductionRobotic guidance (RG) and computer-assisted navigation (NV) have seen increased adoption in instrumented spine surgery over the last decade. Although there exists some evidence that these techniques increase radiological pedicle screw accuracy compared with conventional freehand (FH) surgery, this may not directly translate to any tangible clinical benefits, especially considering the relatively high inherent costs. As a non-randomised, expertise-based study, the European Robotic Spinal Instrumentation Study aims to create prospective multicentre evidence on the potential comparative clinical benefits of RG, NV and FH in a real-world setting.Methods and analysisPatients are allocated in a non-randomised, non-blinded fashion to the RG, NV or FH arms. Adult patients that are to undergo thoracolumbar pedicle screw instrumentation for degenerative pathologies, infections, vertebral tumours or fractures are considered for inclusion. Deformity correction and surgery at more than five levels represent exclusion criteria. Follow-up takes place at 6 weeks, as well as 12 and 24 months. The primary endpoint is defined as the time to revision surgery for a malpositioned or loosened pedicle screw within the first postoperative year. Secondary endpoints include patient-reported back and leg pain, as well as Oswestry Disability Index and EuroQOL 5-dimension questionnaires. Use of analgesic medication and work status are recorded. The primary analysis, conducted on the 12-month data, is carried out according to the intention-to-treat principle. The primary endpoint is analysed using crude and adjusted Cox proportional hazards models. Patient-reported outcomes are analysed using baseline-adjusted linear mixed models. The study is monitored according to a prespecified monitoring plan.Ethics and disseminationThe study protocol is approved by the appropriate national and local authorities. Written informed consent is obtained from all participants. The final results will be published in an international peer-reviewed journal.Trial registration numberClinical Trials.gov registryNCT03398915; Pre-results, recruiting stage.

OBJECTIVEAlthough several studies have suggested that the incidence of intracranial aneurysms (IAs) is higher in smokers, the higher prevalence of subarachnoid hemorrhage (SAH) in smokers remains uncertain. It is unclear whether smoking additionally contributes to the formation of multiple aneurysms and the risk of rupture. The aim of this study was to determine whether smoking is associated with IA formation, multiplicity, or rupture.METHODSPatients from the prospective multicenter @neurIST database (n = 1410; 985 females [69.9%]) were reviewed for the presence of SAH, multiple aneurysms, and smoking status. The prevalence of smokers in the population of patients diagnosed with at least one IA was compared with that of smokers in the general population.RESULTSThe proportion of smokers was higher in patients with IAs (56.2%) than in the reference population (51.4%; p < 0.001). A significant association of smoking with the presence of an IA was found throughout group comparisons (p = 0.01). The presence of multiple IAs was also significantly associated with smoking (p = 0.003). A trend was found between duration of smoking and the presence of multiple IAs (p = 0.057). However, the proportion of smokers among patients suffering SAH was similar to that of smokers among patients diagnosed with unruptured IAs (p = 0.48).CONCLUSIONSSmoking is strongly associated with IA formation. Once an IA is present, however, smoking does not appear to increase the risk of rupture compared with IAs in the nonsmoking population. The trend toward an association between duration of smoking and the presence of multiple IAs stresses the need for counseling patients with IAs regarding lifestyle modification.

The online version of the original article can be found at https://doi.org/10.1007/s00701-019-03812-9

OBJECTIVEThe objective of this study was to determine patterns of care and outcomes in ruptured intracranial aneurysms (IAs) of the middle cerebral artery (MCA) in a contemporary national cohort.METHODSThe authors conducted a retrospective analysis of prospective data from a nationwide multicenter registry of all aneurysmal subarachnoid hemorrhage (aSAH) cases admitted to a tertiary care neurosurgical department in Switzerland in the years 2009–2015 (Swiss Study on Aneurysmal Subarachnoid Hemorrhage [Swiss SOS]). Patterns of care and outcomes at discharge and the 1-year follow-up in MCA aneurysm (MCAA) patients were analyzed and compared with those in a control group of patients with IAs in locations other than the MCA (non-MCAA patients). Independent predictors of a favorable outcome (modified Rankin Scale score ≤ 3) were identified, and their effect size was determined.RESULTSAmong 1866 consecutive aSAH patients, 413 (22.1%) harbored an MCAA. These MCAA patients presented with higher World Federation of Neurosurgical Societies grades (p = 0.007), showed a higher rate of concomitant intracerebral hemorrhage (ICH; 41.9% vs 16.7%, p < 0.001), and experienced delayed cerebral ischemia (DCI) more frequently (38.9% vs 29.4%, p = 0.001) than non-MCAA patients. After adjustment for confounders, patients with MCAA were as likely as non-MCAA patients to experience DCI (aOR 1.04, 95% CI 0.74–1.45, p = 0.830). Surgical treatment was the dominant treatment modality in MCAA patients and at a significantly higher rate than in non-MCAA patients (81.7% vs 36.7%, p < 0.001). An MCAA location was a strong independent predictor of surgical treatment (aOR 8.49, 95% CI 5.89–12.25, p < 0.001), despite statistical adjustment for variables traditionally associated with surgical treatment, such as (space-occupying) ICH (aOR 1.73, 95% CI 1.23–2.45, p = 0.002). Even though MCAA patients were less likely to die during the acute hospitalization (aOR 0.52, 0.30–0.91, p = 0.022), their rate of a favorable outcome was lower at discharge than that in non-MCAA patients (55.7% vs 63.7%, p = 0.003). At the 1-year follow-up, 68.5% and 69.6% of MCAA and non-MCAA patients, respectively, had a favorable outcome (p = 0.676).CONCLUSIONSMicrosurgical occlusion remains the predominant treatment choice for about 80% of ruptured MCAAs in a European industrialized country. Although patients with MCAAs presented with worse admission grades and greater rates of concomitant ICH, in-hospital mortality was lower and long-term disability was comparable to those in patients with non-MCAA.

Obstruction is a common cause of ventriculo-peritoneal shunt failure. Head computed tomography and plain x-ray examinations of shunt tubing (“shunt series”) are routinely used in patients readmitted for reemerging symptoms but are of limited value. The validity of shunt series can be improved by applying contrast agent into the system (contrast-enhanced shunt series, a.k.a. a “shuntogram” or “shuntography”). We hypothesized that contrast-enhanced shunt series have a high predictive value for shunt revision surgeries. We retrospectively re-evaluated 107 contrast-enhanced shunt series and reviewed the patient histories. We defined outcome parameters for calculating the utility of a pathological contrast-enhanced shunt series in predicting revision surgery. Of 107 contrast-enhanced shunt series, 41 examinations were positive for obstruction, mainly of the ventricular (36.5 %) and the peritoneal catheter (48.8 %). Within 30 days, 35 successful revision surgeries and 3 revision surgeries without resolution of symptoms were performed. In two cases the shunt tubing was found to be patent. Sixty-six negative examinations resulted in two revision surgeries, in addition to ten surgeries not attempting to restore patency. After 30 days, the specificity of contrast-enhanced shunt series for shunt failure identification was calculated at 92.8 %, the sensitivity at 94.7 %, the positive predictive value at 87.8 %, and the negative predictive value at 97.0 %. The contrast-enhanced shunt series method is a highly specific examination with a negative predictive value exceeding that of head computed tomography and plain shunt series. Compared to radionuclide marker studies, contrast-enhanced shunt series demonstrate better spatiotemporal resolution, enabling focused local surgical repair.

OBJECTIVEPyogenic spondylodiscitis affects a fragile patient population. Surgical treatment in cases of instability entails instrumentation, and loosening of this instrumentation is a frequent occurrence in pyogenic spondylodiscitis. The authors therefore attempted to investigate whether low bone mineral density (BMD)—which is compatible with the diagnosis of osteoporosis—is underdiagnosed in patients with pyogenic spondylodiscitis. How osteoporosis was treated and how it affected implant stability were further analyzed.METHODSCharts of patients who underwent operations for pyogenic spondylodiscitis were retrospectively reviewed for clinical data, prior medical history of osteoporosis, and preoperative CT scans of the thoracolumbar spine. In accordance with a previously validated high-fidelity opportunistic CT assessment, average Hounsfield units (HUs) in vertebral bodies of L1 and L4 were measured. Based on the validation study, the authors opted for a conservative cutoff value for low BMD, being compatible with osteoporosis ≤ 110 HUs. Baseline and outcome variables, including implant failure and osteoporosis interventions, were entered into a multivariate logistic model for statistical analysis.RESULTSOf 200 consecutive patients who underwent fusion surgery for pyogenic spondylodiscitis, 64% (n = 127) were male and 66% (n = 132) were older than 65 years. Seven percent (n = 14) had previously been diagnosed with osteoporosis. The attenuation analysis revealed HU values compatible with osteoporosis in 48% (95/200). The need for subsequent revision surgery due to implant failure showed a trend toward an association with estimated low BMD (OR 2.11, 95% CI 0.95–4.68, p = 0.067). Estimated low BMD was associated with subsequent implant loosening (p < 0.001). Only 5% of the patients with estimated low BMD received a diagnosis and pharmacological treatment of osteoporosis within 1 year after spinal instrumentation.CONCLUSIONSRelying on past medical history of osteoporosis is insufficient in the management of patients with pyogenic spondylodiscitis. This is the first study to identify a substantially missed opportunity to detect osteoporosis and to start pharmacological treatment after surgery for prevention of implant failure. The authors advocate for routine opportunistic CT evaluation for a better estimation of bone quality to initiate diagnosis and treatment for osteoporosis in these patients.

Background: In glioma surgery, 5-aminolevulinic acid (5-ALA) fluorescence reflects tumor infiltration, and fluorescence-assisted resection correlates with higher removal rates and improved progression-free survival. Recent studies report that a sizable proportion of brain metastases exhibit peritumoral infiltration on the cellular level. There is little information regarding whether 5-ALA is useful to guide surgery in the peritumoral zone in metastases. The aim of this study was to assess histologically whether 5-ALA fluorescence accurately reflects metastatic brain infiltration. Methods and Materials: Fluorescence-assisted tumor resection was performed in 27 patients with brain metastases. Patients received 20 mg/kg 5-ALA 3 hours before anesthesia. After resection, biopsy specimens of the surrounding parenchyma were analyzed for 5-ALA fluorescence and histologic evidence of infiltrating tumor cells. The correlation between 5-ALA positivity and immunohistochemical evidence of tumor in the peritumoral zone was also assessed. Results: Of 27 metastases, 23 (85%) were 5-ALA positive. For qualitative tissue analysis, 110 of 125 samples were collected. Metastatic infiltration was present in 49 samples with faint or red fluorescence; 33 samples without fluorescence were tumor-free. The presence of metastatic infiltration correlated with fluorescence (P < 0.001). Tumor infiltration correlated with fluorescence (blue fluorescence 0.09% ± 0.04% and red or faint fluorescence 3.26%; P = 0.003). Conclusions: Infiltration of surrounding brain tissue is a common finding in brain metastases in selected primary tumors. 5-ALA fluorescence correlates with tumor cell infiltration and might guide more radical resection. Key words: 5-ALA, Brain metastasis, Brain tumor, Fluorescence-guided surgery, Histology, Tumor infiltration

Grading scales yield objective measure of the severity of aneurysmal subarachnoid hemorrhage and serve as to guide treatment decisions and for prognostication. The purpose of this cohort study was to determine what factors govern a patient's disease-specific admission scores in a representative Central European cohort. The Swiss Study of Subarachnoid Hemorrhage includes anonymized data from all tertiary referral centers serving subarachnoid hemorrhage patients in Switzerland. The 2009-2014 dataset was used to evaluate the impact of patient and aneurysm characteristics on the patients' status at admission using descriptive and multivariate regression analysis. The primary/co-primary endpoints were the GCS and the WFNS grade. The secondary endpoints were the Fisher grade, the presence of a thick cisternal or ventricular clot, the presence of a new focal neurological deficit or cranial nerve palsy, and the patient's intubation status. In our cohort of 1787 consecutive patients, increasing patient age by 10 years and low pre-ictal functional status (mRS 3-5) were inversely correlated with "high" GCS score (GCS ≥ 13) (OR 0.91, 95% CI 0.84-0.97 and OR 0.67, 95% CI 0.31-1.46), "low" WFNS grade (grade VI-V) (OR 1.21, 95% CI 1.04-1.20 and OR 1.47, 95% CI 0.66-3.27), and high Fisher grade (grade III-IV) (OR 1.08, 95% CI 1.00-1.17 and OR 1.54, 95% CI 0.55-4.32). Other independent predictors for the patients' clinical and radiological condition at admission were the ruptured aneurysms' location and its size. In sum, chronological age and pre-ictal functional status, as well as the ruptured aneurysm's location and size, determine the patients' clinical and radiological condition at admission to the tertiary referral hospital.

Dear Editor, Oxidized regenerated cellulose (ORC, Surgicel®, Ethicon Inc.) is widely used as a hemostatic fleece. The manufacturer recommends removing as much ORC as possible before closure. As one of the possible complications of its use, postoperative neurological compression symptoms caused by so-called “surgiceloma” have been described in the spine [1] and brain [2, 4]. Since this entity regularly occurs despite better knowledge, we would like to share our experience with a catastrophic complication following the inappropriate use of ORC in spinal surgery. A 54-year-old male underwent posterolateral thoracotomy for a Pancoast tumor T4N0M0 of the right upper pulmonary lobe with infiltration of the vertebral body of Th2 at another institution. The patient awoke from surgery without neurological deficits. On postoperative day 1, he fell asleep in the afternoon and woke up with paraplegia and complete sensory loss in his right leg. An emergencyMRI showed a mass lesion within the spinal canal at the Th2 level (Fig. 1a) whereupon the patient was transferred to our department for neurosurgical treatment. After a Th2-Th3 laminectomy (Fig. 1b), we found ORC material compressing the spinal cord from the right side and penetrating the dura, creating a cerebrospinal fluid (CSF) leak. A postoperative MRI showed the sequelae of the compression as an intramedullary hyperintense signal on T2-weighted imaging at the Th2-Th3 level (Fig. 1c). The patient was sent to rehabilitation with some recovery in the left leg. He died 1 year later because of the progression of the underlying oncological disease. We found 17 (N=17) reports of delayed neural compression due to ORC after a comprehensive MEDLINE search, and we would like to summarize the most salient features. Almost half of the described procedures (8/17=47 %) were thoracotomies at vertebral levels Th3 to Th8 for resection of neoplasms in adults. Three pediatric cases of thoracic surgery that resulted in neural compression syndromes due to ORC were also reported. Median time to symptom discovery was at 30 h postoperatively. The delayed occurrence of symptoms indicates that neurological deficits were not due to inadequate application of pressure on neural structures, but due to delayed swelling of the hemostatic material that was left in place and subsequent migration of material into the spinal canal via the neuroforamen. Eleven out of 17 patients (64 %) already had complete paraplegia at the time of reoperation. This indicates that by the time of symptom onset, the damage to the spinal cord is almost irreversible and decompression—if at all—only partly attenuates the damage. Hemostatic agents can be hypointense on T1and T2weighted imaging and may therefore be indistinguishable from (1) epidural hematoma or (2) a herniated disc on MRI [3]. In most of the literature, the “surgiceloma” was described as an extradural mass. While careful hemostasis during spinal and thoracic procedures is mandatory, it is also necessary to remain mindful of the amount of hemostatic materials we leave in situ. Removal of hemostatic fabric after successful hemostasis can prevent debilitating complications.

Background and Purpose— To identify predictors of in-hospital mortality in patients with aneurysmal subarachnoid hemorrhage and to estimate their impact. Methods— Retrospective analysis of prospective data from a nationwide multicenter registry on all aneurysmal subarachnoid hemorrhage cases admitted to a tertiary neurosurgical department in Switzerland (Swiss SOS [Swiss Study on Aneurysmal Subarachnoid Hemorrhage]; 2009–2015). Both clinical and radiological independent predictors of in-hospital mortality were identified, and their effect size was determined by calculating adjusted odds ratios (aORs) using multivariate logistic regression. Survival was displayed using Kaplan–Meier curves. Results— Data of n=1866 aneurysmal subarachnoid hemorrhage patients in the Swiss SOS database were available. In-hospital mortality was 20% (n=373). In n=197 patients (10.6%), active treatment was discontinued after hospital admission (no aneurysm occlusion attempted), and this cohort was excluded from analysis of the main statistical model. In the remaining n=1669 patients, the rate of in-hospital mortality was 13.9% (n=232). Strong independent predictors of in-hospital mortality were rebleeding (aOR, 7.69; 95% confidence interval, 3.00–19.71; P P P =0.003), and new infarction post-treatment (aOR, 2.57; 95% confidence interval, 1.43–4.62; P =0.002). Conclusions— Several—and among them modifiable—factors seem to be associated with in-hospital mortality after aneurysmal subarachnoid hemorrhage. Our data suggest that strategies aiming to reduce the risk of rebleeding are most promising in patients where active treatment is initially pursued. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT03245866.

BACKGROUND The Barrow Neurological Institute (BNI) scale is a novel quantitative scale measuring maximal subarachnoid hemorrhage (SAH) thickness to predict delayed cerebral ischemia (DCI). This scale could replace the Fisher score, which was traditionally used for DCI prediction. OBJECTIVE To validate the BNI scale. METHODS All patient data were obtained from the prospective aneurysmal SAH multicenter registry. In 1321 patients, demographic data, BNI scale, DCI, and modified Rankin Scale (mRS) score up to the 1-yr follow-up (1FU) were available for descriptive and univariate statistics. Outcome was dichotomized in favorable (mRS 0-2) and unfavorable (mRS 3-6). Odds ratios (OR) for DCI of Fisher 3 patients (n = 1115, 84%) compared to a control cohort of Fisher grade 1, 2, and 4 patients (n = 206, 16%) were calculated for each BNI grade separately. RESULTS Overall, 409 patients (31%) developed DCI with a high DCI rate in the Fisher 3 cohort (34%). With regard to the BNI scale, DCI rates went up progressively from 26% (BNI 2) to 38% (BNI 5) and corresponding OR for DCI increased from 1.9 (1.0-3.5, 95% confidence interval) to 3.4 (2.1-5.3), respectively. BNI grade 5 patients had high rates of unfavorable outcome with 75% at discharge and 58% at 1FU. Likelihood for unfavorable outcome was high in BNI grade 5 patients with OR 5.9 (3.9-8.9) at discharge and OR 6.6 (4.1-10.5) at 1FU. CONCLUSION This multicenter external validation analysis confirms that patients with a higher BNI grade show a significantly higher risk for DCI; high BNI grade was a predictor for unfavorable outcome at discharge and 1FU.

Background Anatomic shape of the spinal canal (oval, round, trefoil) has been reported to predict outcome of bilateral decompression performed in an undercutting technique via unilateral laminotomy in monosegmental lumbar spinal stenosis, with poorest results observed in a trefoil spinal canal, leading to the proposal of using bilateral instead of unilateral laminotomy. The aim of this study was to assess whether this anatomic classification into oval, round, and trefoil shapes is relevant to surgical treatment of lumbar spinal stenosis. Methods Retrospective chart review of patients undergoing lumbar decompression surgery was performed. Spinal canal configuration was assessed on preoperative computed tomography based on maximal transverse and anteroposterior diameter, and shapes were classified into oval, round, and trefoil. Associations between spinal canal shape and outcome improvement (aggregate of walking distance and leg pain) were tested. Results Decompression of 236 lumbar levels was performed in 159 patients (mean age, 73 ± 8 years; mean body mass index, 29 ± 6). Average number of operated segments was 1.3 ± 0.6. Oval configurations were detected in 155 (65%) levels, round configurations were detected in 11 (5%) levels, and trefoil configurations were detected in 70 (30%) levels. Postoperative improvement was recorded in 91.7% of patients. Spinal canal shape had no influence on surgical outcome (oval, area under the curve 0.529, P = 0.672; trefoil, area under the curve 0.500, P = 0.997; round, area under the curve 0.471, P = 0.670). Conclusions Spinal canal configuration varies in frequency with lumbar segment. Our results do not support the idea that this anatomic classification, particularly the nomenclature of oval, round, and trefoil, should influence surgical decision making.

OBJECTIVE Since the introduction of modern surgical techniques and monitoring tools for the treatment of severe traumatic brain injury (TBI) in Switzerland, standardized nationwide operative procedures are still lacking. This study aimed to assess surgical management and monitoring strategies in patients admitted throughout Switzerland with severe TBI. METHODS Demographic, clinical, and radiologic data from a prospective national cohort study on severe brain-injured patients (Patient-relevant Endpoints after Brain Injury from Traumatic Accidents [PEBITA]) were collected during a 3-year period. This study evaluated patients admitted to 7 of the 11 trauma centers included in PEBITA. We retrospectively analyzed surgery-related computed tomography (CT) findings prior to and after treatment, intracranial pressure (ICP) monitoring, size and technical features of craniotomy, as well as surgical complications. ResULTS: This study included 353 of the 921 patients enrolled in PEBITA who underwent surgical treatment for severe TBI. At admission, acute subdural hematoma was the most frequent focal lesion diagnosed (n = 154 [44%]), followed by epidural hematoma (n = 96 [27%]) and intracerebral hematoma (n = 84 [24%]). A total of 198 patients (61%) presented with midline shift. Clinical deterioration in terms of Glasgow Coma Scale scores or intractable ICP values as an indication for surgical evacuation or decompression were documented in 20% and 6%, respectively. A total of 97 (27.5%) only received a catheter/probe for ICP monitoring. Surgical procedures to treat a focal lesion or decompress the cerebrum were performed in 256 patients (72.5%). Of the 290 surgical procedures (excluding ICP probe implantation), craniotomy (137 [47.2%]) or decompressive craniectomy (133 [45.9%]) were performed most frequently. The mean size of craniectomy in terms of maximal linear width on the CT axial slice was 8.4 ± 2.9 cm. Intraoperative ICP monitoring was reported in 61% of the interventions. Significant intraoperative brain swelling was documented in 50.6% of the procedures. Surgery-related complications occurred in 89 cases (32%). CONCLUSION This study highlights the lack of standardized and systematic documentation of technical aspects of surgical treatment of patients presenting with severe TBI in Switzerland. Technical strategies such as size of craniectomy and the use of perioperative ICP measurement were not documented in a standardized manner. A prospective systematic surgical documentation system might contribute to future formulation of recommendations for the surgical treatment of patients presenting with severe TBI in Switzerland.

In industrialized countries, more than two thirds of the population suffers from low back pain (LBP) in their lifetime. LBP associated with lumbar disc herniation, stenosis, and instability is a well-known and documented entity. On the other hand, the lumbar discogenic pain and facet syndrome are difficult to be clearly identified, and they are not always detectable by imaging. This article describes the causes of these painful syndromes, which are typically without radicular component, explains the modern diagnostic procedures, and provides guidelines for surgical decision making.

OBJECTIVE The cause precipitating intracranial aneurysm rupture remains unknown in many cases. It has been observed that aneurysm ruptures are clustered in time, but the trigger mechanism remains obscure. Because solar activity has been associated with cardiovascular mortality and morbidity, we decided to study its association to aneurysm rupture in the Swiss population. METHODS Patient data were extracted from the Swiss SOS database, at time of analysis covering 918 consecutive patients with angiography-proven aneurysmal subarachnoid hemorrhage treated at 7 Swiss neurovascular centers between January 1, 2009, and December 31, 2011. The daily rupture frequency (RF) was correlated to the absolute amount and the change in various parameters of interest representing continuous measurements of solar activity (radioflux [F10.7 index], solar proton flux, solar flare occurrence, planetary K-index/planetary A-index, Space Environment Services Center [SESC] sunspot number and sunspot area) using Poisson regression analysis. RESULTS During the period of interest, there were 517 days without recorded aneurysm rupture. There were 398, 139, 27, 12, 1, and 1 days with 1, 2, 3, 4, 5, and 6 ruptures per day. Poisson regression analysis demonstrated a significant correlation of F10.7 index and RF (incidence rate ratio [IRR] = 1.006303; standard error (SE) 0.0013201; 95% confidence interval (CI) 1.003719-1.008894; P < 0.001), according to which every 1-unit increase of the F10.7 index increased the count for an aneurysm to rupture by 0.63%. A likewise statistically significant relationship of both the SESC sunspot number (IRR 1.003413; SE 0.0007913; 95% CI 1.001864-1.004965; P < 0.001) and the sunspot area (IRR 1.000419; SE 0.0000866; 95% CI 1.000249-1.000589; P < 0.001) emerged. All other variables analyzed showed no significant correlation with RF. CONCLUSIONS We found greater radioflux, SESC sunspot number, and sunspot area to be associated with an increased count of aneurysm rupture. The clinical meaningfulness of this statistical association must be interpreted carefully and future studies are warranted to rule out a type-1 error.

Ventricular pneumocephalus is a rare but potentially life-threatening complication of cranial surgery in the sitting position. The objective of the study is to assess the incidence and risk factors of postoperative ventricular pneumocephalus. We performed a retrospective chart review of 307 consecutive patients (147 men, 160 women) treated at our institution by intracranial surgery in the sitting position from January 2010 to October 2014. Ventricular air entrapment with lack of arousal or neurologic deterioration requiring external ventriculostomy (EVD) was defined as ventricular tension pneumocephalus (VTP). Demographic variables were recorded along with radiological and clinical data. The occurrence of pneumocephalus was correlated with patient-related and surgical variables. VTP was observed in 12 cases (3.9%). These patients had higher intraventricular air volumes (48.5 cm3 (CI 95% [29.06–67.86])) compared to asymptomatic patients (7.4 cm3 (CI 95% [5.43–9.48])). Opening of the fourth ventricle was the most potent predictor of VTP (OR = 34.7, CI 95% [4.4–273.5], p = 0.001). In patients undergoing no additional treatment for pneumocephalus, ventricular air volume declined to an average of 41.7% of the initial postoperative volume on postoperative day 3. Entrapment of intracranial and particularly ventricular air requiring emergent EVD occurred in 3.9% cases of intracranial surgery in the sitting position. Especially the opening of the fourth ventricle was associated with the development of VTP, which should warrant particularly diligent postoperative observation of these patients. In cases without neurological symptoms, the rate of spontaneous air resorption is sufficiently high to warrant expectant management.

Background Osteolysis and implant loosening are commonly encountered problems after spinal instrumentation. Case Description In a patient who had previously undergone a posterior lumbar interbody fusion procedure, fusion did not occur, and a secondary cage dislocation led to an impingement of the L5 nerve root with severe radiculopathy. Revision surgery was performed. Intraoperatively, osteolysis was found to be so severe that conventional cages did not fill the void to allow for sufficient anterior column support. We used expandable transforaminal lumbar interbody fusion cages and implanted them bilaterally to replace the dislodged posterior lumbar interbody fusion cages. Clinical follow-up was uneventful. Imaging performed at 1 year showed satisfactory cage position and fusion. Conclusions We propose the use of cages with the ability of ventral distraction in similar rescue interventions with cage dislocation and bone resorption. This may prevent a second surgery via a ventral approach.

OBJECTIVEThe quest to improve the safety and accuracy and decrease the invasiveness of pedicle screw placement in spine surgery has led to a markedly increased interest in robotic technology. The SpineAssist from Mazor is one of the most widely distributed robotic systems. The aim of this study was to compare the accuracy of robot-guided and conventional freehand fluoroscopy-guided pedicle screw placement in thoracolumbar surgery.METHODSThis study is a retrospective series of 169 patients (83 women [49%]) who underwent placement of pedicle screw instrumentation from 2007 to 2015 in 2 reference centers. Pathological entities included degenerative disorders, tumors, and traumatic cases. In the robot-assisted cohort (98 patients, 439 screws), pedicle screws were inserted with robotic assistance. In the freehand fluoroscopy-guided cohort (71 patients, 441 screws), screws were inserted using anatomical landmarks and lateral fluoroscopic guidance. Patients treated before 2009 were included in the fluoroscopy cohort, whereas those treated since mid-2009 (when the robot was acquired) were included in the robot cohort. Since then, the decision to operate using robotic assistance or conventional freehand technique has been based on surgeon preference and logistics. The accuracy of screw placement was assessed based on the Gertzbein-Robbins scale by a neuroradiologist blinded to treatment group. The radiological slice with the largest visible deviation from the pedicle was chosen for grading. A pedicle breach of 2 mm or less was deemed acceptable (Grades A and B) while deviations greater than 2 mm (Grades C, D, and E) were classified as misplacements.RESULTSIn the robot-assisted cohort, a perfect trajectory (Grade A) was observed for 366 screws (83.4%). The remaining screws were Grades B (n = 44 [10%]), C (n = 15 [3.4%]), D (n = 8 [1.8%]), and E (n = 6 [1.4%]). In the fluoroscopy-guided group, a completely intrapedicular course graded as A was found in 76% (n = 335). The remaining screws were Grades B (n = 57 [12.9%]), C (n = 29 [6.6%]), D (n = 12 [2.7%]), and E (n = 8 [1.8%]). The proportion of non-misplaced screws (corresponding to Gertzbein-Robbins Grades A and B) was higher in the robot-assisted group (93.4%) than the freehand fluoroscopy group (88.9%) (p = 0.005).CONCLUSIONSThe authors’ retrospective case review found that robot-guided pedicle screw placement is a safe, useful, and potentially more accurate alternative to the conventional freehand technique for the placement of thoracolumbar spinal instrumentation.

Postoperative wound healing can pose a problem in patients undergoing instrumented surgery for pyogenic spondylodiscitis. Robotic guidance allows the minimally invasive placement of pedicle screws in the thoracolumbar spine. We assessed whether using this technique to perform minimally invasive surgery had an impact on wound healing in patients with pyogenic spondylodiscitis when compared to conventional open fluoroscopy-guided surgery. We reviewed charts of 206 consecutive patients who underwent instrumentation for pyogenic spondylodiscitis. The need for wound revision was the primary outcome measure. Patient variables and comorbidities as well as surgical technique (robotic versus fluoroscopy-guided) were analyzed. We also compared fluoroscopy times between the two groups. Multivariate regression analysis was performed to identify predictors of wound breakdown. A total of 206 patients underwent surgery for spondylodiscitis. Robotic surgical assistance was used for percutaneous instrumentation in 47.6% of cases (n = 98). Wound healing problems requiring revision occurred in 30 out of 206 patients (14.6%). Univariate analysis revealed a potential association of wound breakdown with (1) robotic technique, (2) age > 70 years, and (3) the presence of methicillin-resistant Staphylococcus aureus. After multivariate correction however, only robotic technique retained significance with an odds ratio of 0.39 (CI 95% 0.16–0.94; p = 0.035). Wound revision was required in eight out of 98 patients (8.1%) in the robot group and 22/108 (20%) in the conventional surgery group. Fluoroscopy times were significantly lower in the robot group with a mean of 123 ± 86 s in comparison with a mean of 157 ± 99 s in the conventional group (p = 0.014). While initially designed to improve the accuracy of pedicle screw placement, robot-assisted minimally invasive technique had a tangible effect on both radiation exposure and the rate of wound breakdown in patients with pyogenic spondylodiscitis in our large single-center study.

With the concept of the hybrid operating room gaining popularity, the authors adapted a hybrid angiographic suite with intraoperative computed tomography (iCT) to evaluate accuracy of pedicle screw placement in spinal fusion. This retrospective review examines how well iCT detected extrapedicular screw violation, to then allow repositioning and potentially avoid revision surgery.A total of 36 consecutive patients underwent pedicle screw placement in posterior cervical, thoracic, and lumbosacral spinal fusions. All patients underwent iCT in the Philips AlluraXper FD20 angiography suite in the lumbar spine XperCT mode and postoperative conventional computed tomography (CT) scanning. Primary endpoints included the sensitivity and specificity of iCT in detecting pedicular violation characterized as minor, moderate, or severe when compared with postoperative CT. Secondary endpoint included the incidence of replaced screws during surgery and number of revision surgeries.Of 241 screws placed in 16 males and 20 females, iCT detected severe pedicle violation in 25 screws (10.4%); 16 screws were then repositioned during surgery. Sensitivity and specificity of iCT to detect severe screw malposition were 92.3% and 99.1%, respectively. No revision surgeries were performed in this series.In our series, iCT had high sensitivity and specificity in detecting severe screw malposition. As a valuable adjunct for intraoperative assessment of pedicle screw position, immediate intraoperative correction of misplaced screws then eliminated any revision surgery for our patients.

Background Risk of delayed cerebral ischemia (DCI) in patients with aneurysmal subarachnoid hemorrhage (aSAH) with asymptomatic angiographic vasospasm on admission is unclear in the literature. The goal of this study is to identify predictors of clinical DCI in this group of patients. Methods An exploratory subgroup analysis was conducted in the SAHIT (Subarachnoid Hemorrhage International Trialists) data repository to identify predictors of clinical DCI in patients with good-grade aSAH (World Federation of Neurological Surgeons grade I and II) with angiographic vasospasm on admission. Predictors considered include age, sex, systolic blood pressure at presentation, World Federation of Neurological Surgeon grade, Fisher grade, aneurysm size and location, treatment modality, hydrocephalus requiring external ventricular drain insertion, and severity of vasospasm. The predictors were ranked based on dominance analysis with R2 as fit statistics and assessed in a set of logistic regression analysis models. Results Four data sets out of 16 studies in the SAHIT database were analyzed, with a total of 4125 patients. One hundred and ninety-one patients (4.6%) had asymptomatic angiographic vasospasm at admission. Of those, 78 patients (40.8%) developed clinical DCI. Univariate analysis showed significant associations between severe vasospasm on admission and development of clinical DCI (odds ratio, 9.5, 95% confidence interval, 2.07–43.50; P = 0.004). None of the studied predictors was associated with the development of clinical DCI on multivariate analysis. Conclusions Asymptomatic angiographic vasospasm in patients with good-grade aSAH on admission is uncommon. Further studies are needed to identify high-risk patients for the development of DCI in the context of asymptomatic early vasospasm.

OBJECTIVERobot-guided pedicle screw placement is an established technique for the placement of pedicle screws. However, most studies have focused on degenerative disease. In this paper, the authors focus on metastatic spinal disease, which is associated with osteolysis. The associated lack of dense bone may potentially affect the automatic recognition accuracy of radiography-based surgical assistance systems. The aim of the present study is to compare the accuracy of the SpineAssist robot system with conventional fluoroscopy-guided pedicle screw placement for thoracolumbar metastatic spinal disease.METHODSSeventy patients with metastatic spinal disease who required instrumentation were included in this retrospective matched-cohort study. All 70 patients underwent surgery performed by the same team of experienced surgeons. The decision to use robot-assisted or fluoroscopy-guided pedicle screw placement was based the availability of the robot system. In patients who underwent surgery with robot guidance, pedicle screws were inserted after preoperative planning and intraoperative fluoroscopic matching. In the “conventional” group, anatomical landmarks and anteroposterior and lateral fluoroscopy guided placement of the pedicle screws. The primary outcome measure was the accuracy of screw placement on the Gertzbein-Robbins scale. Grades A and B (< 2-mm pedicle breach) were considered clinically acceptable, and all other grades indicated misplacement. Secondary outcome measures included an intergroup comparison of direction of screw misplacement, surgical site infection, and radiation exposure.RESULTSA total of 406 screws were placed at 206 levels. Sixty-one (29.6%) surgically treated levels were in the upper thoracic spine (T1–6), 74 (35.9%) were in the lower thoracic spine, and the remaining 71 (34.4%) were in the lumbosacral region. In the robot-assisted group (Group I; n = 35, 192 screws), trajectories were Grade A or B in 162 (84.4%) of screws. The misplacement rate was 15.6% (30 of 192 screws). In the conventional group (Group II; n = 35, 214 screws), 83.6% (179 of 214) of screw trajectories were acceptable, with a misplacement rate of 16.4% (35 of 214). There was no difference in screw accuracy between the groups (chi-square, 2-tailed Fisher’s exact, p = 0.89). One screw misplacement in the fluoroscopy group required a second surgery (0.5%), but no revisions were required in the robot group. There was no difference in surgical site infections between the 2 groups (Group I, 5 patients [14.3%]; Group II, 8 patients [22.9%]) or in the duration of surgery between the 2 groups (Group I, 226.1 ± 78.8 minutes; Group II, 264.1 ± 124.3 minutes; p = 0.13). There was also no difference in radiation time between the groups (Group I, 138.2 ± 73.0 seconds; Group II, 126.5 ± 95.6 seconds; p = 0.61), but the radiation intensity was higher in the robot group (Group I, 2.8 ± 0.2 mAs; Group II, 2.0 ± 0.6 mAs; p < 0.01).CONCLUSIONSPedicle screw placement for metastatic disease in the thoracolumbar spine can be performed effectively and safely using robot-guided assistance. Based on this retrospective analysis, accuracy, radiation time, and postoperative infection rates are comparable to those of the conventional technique.

INTRODUCTION To analyze whether the computed tomography angiography (CTA) spot sign predicts the intraprocedural rupture rate and outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS From a prospective nationwide multicenter registry database, 1023 patients with aneurysmal subarachnoid hemorrhage (aSAH) were analyzed retrospectively. Descriptive statistics and logistic regression analysis were used to compare spot sign-positive and -negative patients with aneurysmal intracerebral hemorrhage (aICH) for baseline characteristics, aneurysmal and ICH imaging characteristics, treatment and admission status as well as outcome at discharge and 1-year follow-up (1YFU) using the modified Rankin Scale (mRS). RESULTS A total of 218 out of 1023 aSAH patients (21%) presented with aICH including 23/218 (11%) patients with spot sign. Baseline characteristics were comparable between spot sign-positive and -negative patients. There was a higher clip-to-coil ratio in patients with than without aICH (both spot sign positive and negative). Median aICH volume was significantly higher in the spot sign-positive group (50 ml, 13-223 ml) than in the spot sign-negative group (18 ml, 1-416; p

Background Prior studies have shown that the incidence of neuropsychological deficits (NPDs) after aneurysmal subarachnoid hemorrhage (aSAH) is high despite excellent outcome according to neurologic grading scales. Delayed cerebral ischemia (DCI) occurs in 30% of patients after aSAH and significantly contributes to the mortality and morbidity of aSAH. We tested the hypothesis that DCI is associated with neuropsychological outcome. Methods Files of patients treated between January 2009 and August 2012 at 2 neurovascular centers were reviewed. Neuropsychological outcome was assessed in a face-to-face-interview of 2–2.5 hours' duration and graded as no (regular), minimal, moderate, or severe deficit according to normative population data by an experienced, independent neuropsychologist. The test battery was applied with consideration of the patients' individual premorbid level of workload and social activities and accounted for the following cognitive domains: memory, attention, executive function, visual and spatial perception, language and calculation, and behavior. Results Of 226 patients treated at 2 centers, 187 were discharged alive. Full neuropsychological outcome assessment was available in 92 patients. DCI developed in 28 (30.4%) patients; 24 of these patients (85.7%) showed moderate to severe NPD. From a univariate perspective, patients with DCI were 6.38 times as likely to experience moderate to severe NPD after aSAH as patients without DCI (odds ratio [OR]; 95% confidence interval [CI], 1.98–20.50; P = 0.002), which remained statistically significant after correction for admission World Federation of Neurological Surgeons Grading System and Fisher scores, patient age, hydrocephalus, and further potential confounders (OR, 4.9; 95% CI, 1.26–19.58; P = 0.022). Of all factors analyzed, DCI was the strongest predictor of NPD in the multivariate analysis, followed by chronic hydrocephalus (OR, 4.85; 95% CI, 1.26–18.63; P = 0.022) and patient age ≥50 years (OR, 4.06; 95% CI, 1.39–11.92; P = 0.001). Conclusions Patients with evidence of DCI during their hospital course have a 5-fold increased risk of experiencing moderate to severe NPD compared with patients who do not develop DCI after aSAH. Secondary events occurring during acute hospitalization (DCI, hydrocephalus) may be more important to the overall neuropsychological outcome than hemorrhage (Fisher) and clinical severity (World Federation of Neurological Surgeons Grading System) scores at admission.

Unilateral posterior inferior cerebellar artery (PICA) thrombosis is frequent. However, bilateral PICA thrombosis is rare. Herein we report about an intraoperative visualization of a bilateral thrombosis of the telovelomedullary segment of the PICA. A 74-year-old woman was admitted to our department on day two of a bilateral PICA thrombosis with developing cerebellar infarction. Her Glasgow Coma Scale score dropped from 15 to 13, and cranial computed tomography revealed compression of the fourth ventricle with consecutive occlusive hydrocephalus. After the insertion of an external ventricular drainage, the patient underwent urgent suboccipital decompressive craniectomy with removal of infarcted cerebellar tonsils, which allowed the bilateral visualization of the thrombosed telovelomedullary segments. The surgical access may offer surgical therapeutic options in a hyperacute occlusion, such as thromb-/embolectomy or bypass procedures.

Background: Multimodality treatment suites for patients with cerebral arteriovenous malformations (AVM) have recently become available. This study was designed to evaluate feasibility, safety and impact on treatment of a new intraoperative flat-panel (FP) based integrated surgical and imaging suite for combined endovascular and surgical treatment of cerebral AVM. Methods: Twenty-five patients with AVMs to treat with combined endovascular and surgical interventions were prospectively enrolled in this consecutive case series. The hybrid suite allows combined endovascular and surgical approaches with intraoperative scanner-like imaging (XperCT®) and intraoperative 3D rotational angiography (3D-RA). The impact of intraoperative multimodal imaging on feasibility, workflow of combined interventions, surgery, and unexpected imaging findings were analyzed. Results: Twenty-five patients (mean age 38 ± 18.6year) with a median Spetzler-Martin grade 2 AVM (range 1-4) underwent combined endovascular and surgical procedures. Sixteen patients presented with a ruptured AVM and nine with an unruptured AVM. In 16% (n = 4) of cases, intraoperative imaging visualized AVM remnants ≤3mm and allowed for completion of the resections in the same sessions. Complete resection was confirmed in all n = 16 patients who had follow-up angiography oneyear after surgery so far. All diagnostic and therapeutical steps, including angiographic control, were performed without having to move the patients Conclusion: The hybrid neurointerventional suite was shown to be a safe and useful setup which allowed for unconstrained combined microsurgical and neuroradiological workflow. It reduces the need for extraoperative angiographic controls and subsequent potential surgical revisions a second time, as small AVM remnants can be detected with high security

BACKGROUND: Aneurysmal subarachnoid haemorrhage (SAH) WFNS grade V is commonly known to be associated with high mortality and a very poor prognosis for survivors. Therefore, maximal invasive therapy is frequently delayed until any spontaneous improvement with or without an external ventricular drainage occurs. The aim of the study was to verify possible predictive factors and the probability of a favourable outcome in maximally treated patients. METHODS: One hundred and thirty-eight consecutive patients with WFNS grade V SAH were admitted between 03/2006 and 12/2010. Thirty-five patients died before aggressive therapy could proceed. One hundred and three patients received maximal treatment and were retrospectively evaluated. The outcome was assessed at discharge and in the follow-up with the Glasgow Outcome Scale. Univariate and multivariate linear regression models were performed to find predictors for an unfavourable outcome. RESULTS: Despite treatment, early mortality was 30 % (n = 31). At discharge, the rate of both vegetative and severely disabled patients was 27 % (n = 28). Favourable outcome at discharge was observed in 16 % (n = 16) of cases, whereas in the follow-up it rose to 26 % (n = 27). Multivariate full model regression identified intraventricular haematoma (IVH) and increasing age as independently predictive for poor outcome. CONCLUSIONS: Despite treatment, initial mortality and severe disability remain high. Nevertheless, a favourable outcome was achieved in 26 % of aggressively treated patients, rendering the withdrawal of maximal therapy for WFNS grade V SAH patients unacceptable today. In cases of old patients with IVH, the indication for aggressive therapy should be put in place more carefully due to a very poor prognosis

Background The choice of the ideal hemostatic agent for intraoperative cerebral bleeding is under continuous debate. Our aim was to assess the influence of such materials on bleeding time in hemorrhagic cerebral contusions. We compared oxidized regenerated cellulose in fibrillar form (ORC) to microfibrillar collagen fleece (CF) in an experimental study. Methods N=50 Sprague Dawley rats underwent a bilateral craniectomy. 3 separate standardized superficial cortical impacts were inflicted using a high-speed drill. Immediately after lesion placement, each of the 3 lesions was covered with (a) nothing (control), (b) ORC, or (c) CF. We observed the 3 lesions with a surgical microscope. The bleeding times were recorded for each cerebral lesion and compared using ANOVA test. Results All traumatic lesions produced significant bleeding. The statistical analysis showed a clear reduction in bleeding time for groups treated with either ORC or CF compared to the control group. Lesions covered with ORC and CF showed no significant difference with regard to bleeding time. Conclusions ORC and CF significantly reduce blood loss from hemorrhagic contusions. Our data suggest that they effectively reduce bleeding time. We advocate the use of hemostatic material for limiting bleeding from superficial cortical lesions.

Recent in vitro evidence suggests that T-type Ca(2+) channels are implicated in the mechanisms of ischemia-induced delayed neuronal cell death. The aim of this work was to study the neuroprotective potential of mibefradil and pimozide, both T-type Ca(2+) channel inhibitors, in an in vivo rat model of global ischemia. We performed blinded and randomized placebo vs. treatment experiments using 57 animals to test mibefradil and fourteen animals to test pimozide. Each treated animal received a single stereotactic intraventricular injection of mibefradil or intraperitoneal injection of pimozide prior to transient global cerebral ischemia. The primary endpoint was the number of neurons surviving in the CA1 region 72 h after insult as evaluated by NeuN-labeled cell counts. All physiological variables monitored immediately before and after ischemic insult were equivalent between all groups. Surviving neurons in the CA1 region were significantly more frequent in the treated groups compared to the placebo group (mibefradil: 36.8 ± 2.8 cells in a 200 × 100 μm counting area vs. placebo: 25.2 ± 3.2 [P < 0.01]; pimozide: 39.4 ± 1.12 vs. placebo: 27.8 ± 0.7 [P < 0.0001]). Thus, administration of mibefradil or pimozide effectively prevents neuronal death after ischemia in a rat model of global ischemia. This study provides further support for a neuroprotective effect of T-type Ca(2+) current inhibition during ischemia.

Knowledge of spinal cord arteriovenous malformations (AVMs) has recently been improved by studies on pathophysiology, neuroimaging, and genetic data. Nevertheless, the natural history of these lesions remains poorly understood. The authors present the case of an angiographic regression of a nidal-type spinal AVM at T-12 to L-1 in a 46-year-old woman with no risk factors. The natural course of untreated lesions is reviewed and discussed. To the best of the authors' knowledge, this is the first study that reports an angiographically proven complete spontaneous occlusion of a spinal AVM.

We examined a bedside technique transcerebral double-indicator dilution (TCID) for global cerebral blood flow (CBF) as well as the concept of effective cerebral perfusion pressure (CPP(eff)) during different treatment options for intracranial hypertension, and compared global CBF and CPP(eff) with simultaneously obtained conventional parameters.Twenty-six patients developing intracranial hypertension in the course of traumatic brain injury or subarachnoid hemorrhage were prospectively analyzed using a combined assessment during elevated ventilation (n = 15) or osmotherapy (hypertonic saline or mannitol). For calculation of global CBF, injections of ice-cold indocyanine green boluses were performed and temperature and dye concentration changes were monitored in the thoracic aorta and the jugular bulb. CBF was then calculated according to the mean transit time principle. Estimation of CCP, the arterial pressure at which cerebral blood flow becomes zero, was performed by synchronized registration of corresponding values of blood flow velocity in the middle cerebral artery and arterial pressure and extrapolation to zero-flow velocity. CPP(eff) was calculated as mean arterial pressure minus critical closing pressure (CPP(eff) = MAP(c) - CCP).Elevated ventilation causes a decrease in both ICP (P0.001) and CBF (P0.001). While CPP(conv) increased (P0.001), CPP(eff) decreased during this observation (P = 0.002). Administration of osmotherapeutic agents resulted in a decrease of ICP (P0.001) and a temporary increase of CBF (P = 0.052). CPP(conv) and CPP(eff) showed no striking difference under osmotherapy.TCID allows repeated measurements of global CBF at the bedside. Elevated ventilation lowered and osmotherapy temporarily raised global CBF. In situations of increased vasotonus, CPP(eff) is a better indicator of blood flow changes than conventional CPP.

Objective - To develop and validate a set of practical prediction tools that reliably estimate the outcome of subarachnoid haemorrhage from ruptured intracranial aneurysms (SAH).Design - Cohort study with logistic regression analysis to combine predictors and treatment modality.Setting - Subarachnoid Haemorrhage International Trialists' (SAHIT) data repository, including randomised clinical trials, prospective observational studies, and hospital registries.Participants - Researchers collaborated to pool datasets of prospective observational studies, hospital registries, and randomised clinical trials of SAH from multiple geographical regions to develop and validate clinical prediction models.Main outcome measure - Predicted risk of mortality or functional outcome at three months according to score on the Glasgow outcome scale.Results - Clinical prediction models were developed with individual patient data from 10 936 patients and validated with data from 3355 patients after development of the model. In the validation cohort, a core model including patient age, premorbid hypertension, and neurological grade on admission to predict risk of functional outcome had good discrimination, with an area under the receiver operator characteristics curve (AUC) of 0.80 (95% confidence interval 0.78 to 0.82). When the core model was extended to a "neuroimaging model," with inclusion of clot volume, aneurysm size, and location, the AUC improved to 0.81 (0.79 to 0.84). A full model that extended the neuroimaging model by including treatment modality had AUC of 0.81 (0.79 to 0.83). Discrimination was lower for a similar set of models to predict risk of mortality (AUC for full model 0.76, 0.69 to 0.82). All models showed satisfactory calibration in the validation cohort.Conclusion - The prediction models reliably estimate the outcome of patients who were managed in various settings for ruptured intracranial aneurysms that caused subarachnoid haemorrhage. The predictor items are readily derived at hospital admission. The web based SAHIT prognostic calculator (http://sahitscore.com) and the related app could be adjunctive tools to support management of patients.

Object Investigators in experimental and clinical studies have used the intrathecal route to deliver drugs to prevent or treat vasospasm. However, a clot near an artery or arteries after subarachnoid hemorrhage (SAH) may hamper distribution and limit the effects of intrathecally delivered compounds. In a primate model of right middle cerebral artery (MCA) SAH, the authors examined the distribution of Isovue-M 300 and 3% Evans blue after infusion into the cisterna magna CSF. Methods Ten cynomolgus monkeys were assigned to SAH and sham SAH surgery groups (5 in each group). Monkeys received CSF injections as long as 28 days after SAH and were killed 3 hours after the contrast/Evans blue injection. The authors assessed the distribution of contrast material on serial CT within 2 hours after contrast injection and during autopsy within 3 hours after Evans blue staining. Results Computed tomography cisternographies showed no contrast in the vicinity of the right MCA (p < 0.05 compared with left); the distribution of contrast surrounding the entire right cerebral hemisphere was substantially reduced. Postmortem analysis demonstrated much less Evans blue staining of the right hemisphere surface compared with the left. Furthermore, the Evans blue dye did not penetrate into the right sylvian fissure, which occurred surrounding the left MCA. The authors observed the same pattern of changes and differences in contrast distribution between SAH and sham SAH animals and between the right and the left hemispheres on Days 1, 3, 7, 14, 21, and 28 after SAH. Conclusions Intrathecal drug distribution is substantially limited by SAH. Thus, when using intrathecal drug delivery after SAH, vasoactive drugs are unlikely to reach the arteries that are at the highest risk of delayed cerebral vasospasm.

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is widely used to evaluate tumor permeability, yet measurements have not been directly validated in brain tumors. Our purpose was to compare estimates of forward leakage K trans derived from DCE-MRI to the estimates K obtained using [ 14 C]aminoisobutyric acid quantitative autoradiography ([ 14 C]AIB OAR), an established method of evaluating blood-tumor barrier permeability. Both DCE-MRI and [ 14 C]AIB OAR were performed in five rats 9 to 11 days following tumor implantation. K trans in the tumor was estimated from DCE-MRI using the threeparameter general kinetic model and a measured vascular input function. K i was estimated from OAR data using regions of interest (ROI) closely corresponding to those used to estimate K trans . K trans and K i correlated with each other for two independent sets of central tumor ROI ( R = 0.905, P = .035; R = 0.933, P = .021). In an additional six rats, K trans was estimated on two occasions to show reproducibility (intraclass coefficient = 0.9993; coefficient of variance = 6.07%). In vivo blood-tumor permeability parameters derived from DCE-MRI are reproducible and correlate with the gold standard for quantifying blood tumor barrier permeability, [ 14 C]AIB OAR.

According to microsurgical principles, the access to deep-seated cerebral lesions should be as atraumatic as possible. Temporary brain retraction is acceptable in certain situations and may be indispensable when the view of the lesion is obstructed. The utility of this method is illustrated in a case of a ruptured middle cerebral artery (MCA) aneurysm. Two temporary aneurysm clips were connected by a braided suture, thus forming a band with two points of attachment. The Sylvian fissure was opened in a standard fashion. Using one clip, the adventitia and arachnoid over the superficial Sylvian vein were grasped firmly enough to mobilize the superficial Sylvian vein. The distal clip was then attached to surrounding drapes, thus granting a direct view of the aneurysm in the depth of the fissure. Retraction with spatula was not necessary. Patency of the superficial Sylvian vein was demonstrated using idocyanine green angiography. We present a simple method for minimally traumatic brain retraction using aneurysm clips attached to the adventitia of Sylvian veins and held back by sutures. The use of clips attached to the adventitia of the superficial Sylvian may be of help in retracting the Sylvian fissure. By virtue of enlarging the field of view into the deep Sylvian fissure, it may be of help in performing retractorless aneurysm surgery.

Objective: Previous studies have shown that both 5-aminolaevulinic acid (5-ALA)-flourescence guided resection (FGR) and intraoperative magnetic resonance imaging (iMRI) enhance the amount of resection and, thereby, improve survival in patients with high-grade glioma. One might therefore assume that [for full text, please go to the a.m. URL], 66. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)