[Show abstract][Hide abstract] ABSTRACT: Background:
The ideal treatment strategy for low-grade gliomas (LGGs) is a controversial topic. Additionally, only smaller single-center series dealing with the concept of intraoperative magnetic resonance imaging (iMRI) have been published.
To investigate determinants for patient outcome and progression-free-survival (PFS) after iMRI-guided surgery for LGGs in a multicenter retrospective study initiated by the German Study Group for Intraoperative Magnetic Resonance Imaging.
A retrospective consecutive assessment of patients treated for LGGs (World Health Organization grade II) with iMRI-guided resection at 6 neurosurgical centers was performed. Eloquent location, extent of resection, first-line adjuvant treatment, neurophysiological monitoring, awake brain surgery, intraoperative ultrasound, and field-strength of iMRI were analyzed, as well as progression-free survival (PFS), new permanent neurological deficits, and complications. Multivariate binary logistic and Cox regression models were calculated to evaluate determinants of PFS, gross total resection (GTR), and adjuvant treatment.
A total of 288 patients met the inclusion criteria. On multivariate analysis, GTR significantly increased PFS (hazard ratio, 0.44; P < .01), whereas "failed" GTR did not differ significantly from intended subtotal-resection. Combined radiochemotherapy as adjuvant therapy was a negative prognostic factor (hazard ratio: 2.84, P < .01). Field strength of iMRI was not associated with PFS. In the binary logistic regression model, use of high-field iMRI (odds ratio: 0.51, P < .01) was positively and eloquent location (odds ratio: 1.99, P < .01) was negatively associated with GTR. GTR was not associated with increased rates of new permanent neurological deficits.
GTR was an independent positive prognostic factor for PFS in LGG surgery. Patients with accidentally left tumor remnants showed a similar prognosis compared with patients harboring only partially resectable tumors. Use of high-field iMRI was significantly associated with GTR. However, the field strength of iMRI did not affect PFS.
EoR, extent of resectionFLAIR, fluid-attenuated inversion recoveryGTR, gross total resectionIDH1, XXXiMRI, intraoperative magnetic resonance imagingLGG, low-grade gliomaMGMT, methylguanine-deoxyribonucleic acid methyltransferasenPND, new permanent neurological deficitOS, overall survivalPFS, progression-free survivalSTR, subtotal resectionWHO, World Health Organization.
[Show abstract][Hide abstract] ABSTRACT: Objective:
to compare the anatomical exposure and petrosectomy extent in the Kawase and PIPA approaches.
Kawase and PIPA approaches were performed on 4 fixed cadaveric heads (3 alcohol-fixed, 1 formaldehyde-fixed silicone-injected, 4 Kawase and 4 PIPA approaches). The microsurgical anatomy was examined by means of Zeiss Opmi CS/NC-4® microscopes. HD Karl Storz Endoscopes (AIDA system) were used to display intradural exposure. Petrosectomy volumes was assessed comparing pre- and post-operative thin-slices CT scans (Analyze 12.0, AnalyzeDirect Mayo Clinic).
Kawase approach exposed the rhomboid fossa with Meckel's cave extradurally, the upper half of the clivus, superior cerebellopontine angle, ventro-lateral brainstem, the intrameatal region, basilar apex, the preganglionic root of CN V, CN III-IV-VI intradurally. PIPA approach exposed the cerebello-pontine angle with CN VI-XII, Meckel's cave, CN III-V, the middle and lower clivus intradurally from a posterior view. The area of surgical exposure is wide in both approaches, however, the volume of petrosectomy, the working angle and surgical corridor differ significantly.
Kawase approach allows wide exposure of the MCF and PCF, requiring extradural temporal lobe retraction and an extradural petrosectomy with preservation of the internal acoustic meatus and cochlea. No temporal lobe retraction and direct control of neurovascular structures make the PIPA approach a valid alternative for lesions extending mostly in the PCF with minor extension in the MCF. The longer surgical corridor, cerebellar retraction, and limited exposure of the anterior brainstem make this approach less indicated for lesions with major extension in the MCF and the anterior cavernous sinus.
World Neurosurgery 10/2015; DOI:10.1016/j.wneu.2015.08.083 · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective
Antiepileptic treatment of brain tumor patients mainly depends on the individual physician's choice rather than on well-defined predictive factors. We investigated the predictive value of defined clinical parameters to formulate a model of risk estimations for subpopulations of brain tumor patients.Methods
We enclosed 650 patients > 18 years of age who underwent brain tumor surgery and included a number of clinical data. Logistic regressions were performed to determine the effect sizes of seizure related risk factors and to develop prognostic scores for the occurrence of preoperative and early postoperative seizures.ResultsA total of 492 patients (334 gliomas) were eligible for logistic regression for preoperative seizures, and 338 patients for early postoperative seizures. Age ≤60 years (OR 1.66, p=0.020), grades I and II glioma (OR 4.00, p=0.0002), total tumor/edema volume ≤64cm3 (OR 2.18, p=0.0003), and frontal location (OR 2.28, p=0.034) demonstrated an increased risk for preoperative seizures. Isocitrate-dehydrogenase mutations (OR 2.52, p=0.026) were an independent risk factor in the glioma subgroup. Age ≥60 years (OR 3.32, p=0.041), total tumor/edema volume ≤64cm3 mm (OR 3.17, p=0.034), complete resection (OR 15.50, p=0.0009), diencephalic location (OR 12.2, p=0.013), and high-grade tumors (OR 5.67, p=0.013) were significant risk factors for surgery-related seizures. Antiepileptics (OR 1.20, p=0.60) did not affect seizure occurrence. For seizure occurrence, patients could be stratified into three prognostic preoperative and into two prognostic early postoperative groups.InterpretationBased on the developed prognostic scores, seizure prophylaxis should be considered in high-risk patients and patient stratification for prospective studies may be feasible in the future. This article is protected by copyright. All rights reserved.
Annals of Neurology 09/2015; DOI:10.1002/ana.24522 · 9.98 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: OBJECT A pilot study of prophylactic nimodipine and hydroxyethyl starch treatment showed a beneficial effect on facial and cochlear nerve preservation following vestibular schwannoma (VS) surgery. A prospective Phase III trial was undertaken to confirm these results. METHODS An open-label, 2-arm, randomized parallel group and multicenter Phase III trial with blinded expert review was performed and included 112 patients who underwent VS surgery between January 2010 and February 2013 at 7 departments of neurosurgery to investigate the efficacy and safety of the prophylaxis. The surgery was performed after the patients were randomly assigned to one of 2 groups using online randomization. The treatment group (n = 56) received parenteral nimodipine (1-2 mg/hr) and hydroxyethyl starch (hematocrit 30%-35%) from the day before surgery until the 7th postoperative day. The control group (n = 56) was not treated prophylactically. RESULTS Intent-to-treat analysis showed no statistically significant effects of the treatment on either preservation of facial nerve function (35 [67.3%] of 52 [treatment group] compared with 34 [72.3%] of 47 [control group]) (p = 0.745) or hearing preservation (11 [23.4%] of 47 [treatment group] compared with 15 [31.2%] of 48 [control group]) (p = 0.530) 12 months after surgery. Since tumor sizes were significantly larger in the treatment group than in the control group, logistic regression analysis was required. The risk for deterioration of facial nerve function was adjusted nearly the same in both groups (OR 1.07 [95% CI 0.34-3.43], p = 0.91). In contrast, the risk for postoperative hearing loss was adjusted 2 times lower in the treatment group compared with the control group (OR 0.49 [95% CI 0.18-1.30], p = 0.15). Apart from dose-dependent hypotension (p < 0.001), no clinically relevant adverse reactions were observed. CONCLUSIONS There were no statistically significant effects of the treatment. Despite the width of the confidence intervals, the odds ratios may suggest but do not prove a clinically relevant effect of the safe study medication on the preservation of cochlear nerve function after VS surgery. Further study is needed before prophylactic nimodipine can be recommended in VS surgery.
Journal of Neurosurgery 08/2015; DOI:10.3171/2015.1.JNS142001 · 3.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intraoperative magnetic resonance imaging (iMRI) has dramatically expanded and nowadays presents state-of-the-art technique for image-guided neurosurgery, facilitating critical precision and effective surgical treatment of various brain pathologies. Imaging hardware providing basic imaging sequences as well as advanced MRI can be seamlessly integrated into routine surgical environments, which continuously leads to emerging indications for iMRI-assisted surgery. Besides the obvious intraoperative diagnostic yield, the initial clinical benefits have to be confirmed by future-controlled long-term studies.
[Show abstract][Hide abstract] ABSTRACT: Tumor resection in the rolandic region, also known as sensorimotor cortex, is a challenge. This study aims at reviewing a series of patients undergoing resection of metastases in the sensorimotor cortex using a multimodal concept including neuronavigation, sonography, and intraoperative electrophysiological monitoring. Eleven patients suffering from metastases located in precentral (8) and postcentral gyrus (3) were analyzed concerning their functional motor outcome. Improvement of motor function could be seen in 5 patients 1 week after surgery, 5 patients remained unchanged, and only 1 deteriorated. Median survival time averaged 15 months. A multimodal approach, including preoperative and intraoperative neuronavigation, intraoperative sonography, and intraoperative electrophysiological monitoring can lead on to excellent functional outcome in surgery of metastases in the sensorimotor cortex. Copyright
[Show abstract][Hide abstract] ABSTRACT: Background/Study Aims Percutaneous radiofrequency trigeminal rhizotomy (RTR) is a standardized treatment for trigeminal neuralgia, yet it has been associated with serious complications related to the cannulation of the foramen ovale. Some of these complications, such as carotid injury, are potentially lethal. Neuronavigation was recently proposed as a method to increase the procedure's safety. All of the techniques described so far rely on pre- or intraoperative computed tomography scanning. Here we present a simple method based on magnetic resonance imaging (MRI) (radiation free) used to target the foramen ovale under navigation guidance. Patients/Material and Methods We retrospectively analyzed nine patients who had undergone navigated percutaneous RTR based solely on preoperative MRI and compared them with 35 patients who underwent conventional RTR guided by fluoroscopy. We analyzed immediate and late outcome and categorized the results into pain free, > 70% pain reduction, and persistent pain. We also compared groups in terms of the duration of the procedure and the complication rates. Here we describe the navigation method in detail and review the anatomical landmarks for target definition. Results The duration of the surgical procedure was similar in both groups (32.1 in the standard technique versus 34.5 minutes with navigation; p = 0.5157). There was no significant difference between groups regarding pain reduction at the immediate (p = 1.0) or late follow-up (p = 0.6284) time points. Furthermore, no serious complications were observed in the navigated group. Conclusions We present a simple radiation-free method for neuronavigation-assisted percutaneous RTR. This method proved to be safe and effective, and it is especially recommended for young, inexperienced neurosurgeons.
Georg Thieme Verlag KG Stuttgart · New York.
Journal of Neurological Surgery. Part A: Central European Neurosurgery 01/2015; 76(02). DOI:10.1055/s-0034-1394190 · 0.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: There are several methods to detect apoptosis using cleaved caspase-3 and each harbors its own advantages and disadvantages. When primary cell cultures are used, the disadvantages of the standard methods can make apoptosis detection difficult due to their slow growth rate and replicative senescence, thereby limiting the available cell number and experiment time span. In this chapter, we describe apoptosis detection and quantification using an innovative method named TaqMan(®) protein assay. TaqMan(®) protein assay uses antibodies and proximity ligation for quantitative real-time PCR. Biotinylated antibodies are labeled with oligonucleotides. When the labeled antibodies bind in close proximity, the oligonucleotides are connected using DNA ligase. The ligation product is amplified and detected using Taqman(®) based Real-Time PCR. Using this technique, we can not only detect apoptosis with a 1,000-fold higher sensitivity than western blot, but we can also exactly quantify cleaved caspase-3 expression. Thereby apoptosis can be determined and quantified in a fast reliable manner.
[Show abstract][Hide abstract] ABSTRACT: Several studies published to date about glioma surgery have addressed the validity of using novel technologies for intraoperative guidance and potentially improved outcomes. However, most of these reports are limited by questionable methods and/or by their retrospective nature. In this work, we performed a systematic review of the literature to address the impact of intraoperative assistive technologies on the extent of resection (EOR) in glioma surgery, compared to conventional unaided surgery. We were also interested in two secondary outcome variables: functional status and progression-free survival. We primarily used PubMed to search for relevant articles. Studies were deemed eligible for our analysis if they (1) were prospective controlled studies; (2) used EOR as their primary target outcome, assessed by MRI volumetric analysis; and (3) had a homogeneous study population with clear inclusion criteria. Out of 493 publications identified in our initial search, only six matched all selection criteria for qualitative synthesis. Currently, the evidence points to 5-ALA, DTI functional neuronavigation, neurophysiological monitoring, and intraoperative MRI as the best tools for improving EOR in glioma surgery. Our sample and conclusions were limited by the fact that studies varied in terms of population characteristics and in their use of different volumetric analyses. We were also limited by the low number of prospective controlled trials available in the literature. Additional evidence-based high-quality studies assessing cost-effectiveness should be conducted to better determine the benefits of intraoperative assistive technologies in glioma surgery.
[Show abstract][Hide abstract] ABSTRACT: The prediction of the long-term outcome of comatose patients after severe traumatic brain injury (TBI) using early somatosensory and acoustic evoked potentials is controversial. It was our aim to examine the different single components of the evoked potentials regarding their predictive capacity in comatose patients.
We examined the amplitude and latency of the wave N20, the amplitude differences between right and left hemisphere, the central conduction time (CCT), the amplitude ratio N20 left/N20 right, the amplitude and latency of peak V, the inter-peak latency I-V and the amplitude ratio V/I. The long-term clinical outcome of the patients was re-evaluated 3 years after their discharge and correlated with the different components.
Only the central conduction time (CCT) and the latency of the wave N20 indicated a statistical correlation with the later outcome (p = 0.0366). The amplitude ratio of wave V/I of the EAEP did not reveal a significant statistical difference between the various outcome groups.
In this study, the use of single components of the SSEP and EAEP per se could not predict the long-term clinical outcome after TBI. Combined systems such as the Riffel Score are necessary in order to achieve this goal.
The Neurodiagnostic journal 12/2014; 54(4):338-52. DOI:10.1080/21646821.2014.11106818
[Show abstract][Hide abstract] ABSTRACT: Visual perception of body motion is vital for everyday activities such as social interaction, motor learning or car driving. Tumors to the left lateral cerebellum impair visual perception of body motion. However, compensatory potential after cerebellar damage and underlying neural mechanisms remain unknown. In the present study, visual sensitivity to point-light body motion was psychophysically assessed in patient SL with dysplastic gangliocytoma (Lhermitte-Duclos disease, WHO grade I) to the left cerebellum before and after neurosurgery, and in a group of healthy matched controls. Brain activity during processing of body motion was assessed by functional MRI. Alterations in underlying cerebro-cerebellar circuitry were studied by psychophysiological interaction (PPI) analysis. Visual sensitivity to body motion in patient SL before neurosurgery was substantially lower than in controls, with significant improvement after neurosurgery. Functional MRI in patient SL revealed a similar pattern of cerebellar activation during biological motion processing as in healthy participants, but located more medially, in the left cerebellar lobules III and IX. As in normalcy, PPI analysis showed cerebellar communication with a region in the superior temporal sulcus, but located more anteriorly. The findings demonstrate a potential for recovery of visual body motion processing, likely mediated by topographic shifts within the corresponding cerebro-cerebellar circuitry induced by damage to the cerebellum. The outcome is of importance for further understanding of cerebellar plasticity and neural circuits underpinning visual social cognition.