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1.
Acta Neurochir (Wien) ; 165(7): 1881-1889, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37178247

RESUMO

BACKGROUND: Since its approval by the US Food and Drug Administration (FDA) in 2018, the flow disruptor Woven EndoBridge (WEB) device has become increasingly popular for the endovascular treatment of unruptured and ruptured cerebral aneurysms. However, the occlusion rates seem rather low and the retreatment rates rather high compared to other treatment methods. For initially ruptured aneurysms, a retreatment rate of 13 % has been reported. A variety of retreatment strategies has been proposed; however, there is a paucity of data concerning microsurgical clipping of WEB-pretreated aneurysms, especially previously ruptured ones. Thus, we present a single-center series of five ruptured aneurysms treated with the WEB device and retreated with microsurgical clipping. METHODS: A retrospective study including all patients presenting with a ruptured aneurysm undergoing WEB treatment at our institution between 2019 and 2021 was performed. Subsequently, all patients with an aneurysm remnant or recurrence of the target aneurysm retreated with microsurgical clipping were identified. RESULTS: Overall, five patients with a ruptured aneurysm treated with WEB and retreated with microsurgical clipping were included. Besides one basilar apex aneurysm, all aneurysms were located at the anterior communicating artery (AComA) complex. All aneurysms were wide-necked with a mean dome-to-neck ratio of 1.5. Clipping was feasible and safe in all aneurysms, and complete occlusion was achieved in 4 of 5 aneurysms. CONCLUSIONS: Microsurgical clipping for initially ruptured WEB-treated aneurysms is a feasible, safe, and effective treatment method in well-selected patients.


Assuntos
Aneurisma Roto , Embolização Terapêutica , Procedimentos Endovasculares , Aneurisma Intracraniano , Humanos , Estudos Retrospectivos , Procedimentos Endovasculares/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Resultado do Tratamento , Aneurisma Roto/diagnóstico por imagem , Aneurisma Roto/cirurgia , Embolização Terapêutica/métodos , Retratamento
2.
Neurosurg Rev ; 44(6): 3421-3425, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33674981

RESUMO

Hygiene measures were intensified when the COVID-19 pandemic began. Patient contacts were limited to a minimum. Visitors were either not allowed for a certain period or limited for the rest of the time. The hospital staff began to wear masks and gloves continuously. Clinical examinations and routine wound controls were also performed under intensified hygiene standards. These circumstances result in a limitation of direct physical interactions between the nursing staff, the physicians and the patients. We analyzed to what extent the intensification of hygiene measures affects the rate of surgical site infections (SSI) after neurosurgical procedures. The rate of SSI during the 6-month interval after the beginning of COVID-19 measures was compared with the SSI rate before. The numbers of the period before COVID-19 were analyzed as mean values resulting from the analysis of two separate time periods each consisting of 6 months. The spectrum of surgical procedures was compared. Patient-related risk factors for SSIs were noted. Microorganisms were analyzed. We focused on SSIs occurring at a maximum of 60 days after the primary surgery. Overall, in the two respective 6-month periods before COVID-19, a mean of 1379 patients was surgically treated in our institution. After the beginning of COVID-19 (starting from 04/2020) our surgical numbers dropped by 101, resulting in a total number of 1278 patients being operated after 03/2020 until 09/2020. The SSI rate was 3.6% (03/2019-09/2019, 50 SSIs) and 2.2% (09/2019-03/2020, 29 SSIs), resulting in a mean of 2.9% before COVID-19 began. After the beginning of COVID-19 hygiene measures, this rate dropped to 1.4% (16 SSIs) resembling a significant reduction (p=0.003). Risk factors for the development of SSI were present in 81.3% of all patients. Pre- and post-COVID-19 patient groups had similar baseline characteristics. The same holds true when comparing the percentage of cranial and spinal procedures pre- and post-COVID-19 (p=0.91). Comparing the numbers (p=0.28) and the species (p=0.85) of microorganisms (MO) causing SSI, we found a similar distribution. Despite equal demographics and characteristics of SSI, the rate of SSI dropped substantially. This argues for an effective reduction of postoperative SSI resulting from the implementation of strict hygiene measures being established after the beginning of the COVID-19 pandemic. We therefore advocate continuing with strict and intensive hygiene measures in the future.


Assuntos
COVID-19 , Neurocirurgia , Humanos , Procedimentos Neurocirúrgicos/efeitos adversos , Pandemias , Fatores de Risco , SARS-CoV-2 , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controle
3.
Neurosurg Rev ; 43(1): 273-279, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30426355

RESUMO

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.


Assuntos
Descompressão Cirúrgica , Edema/cirurgia , Glioma/cirurgia , Procedimentos Neurocirúrgicos/métodos , Neoplasias da Medula Espinal/cirurgia , Adulto , Edema/etiologia , Feminino , Glioma/diagnóstico por imagem , Glioma/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/patologia
4.
Acta Neurochir (Wien) ; 162(5): 1033-1040, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31997071

RESUMO

BACKGROUND: Programmable differential pressure (DP) valves combined with an anti-siphon device (ASD) represent the current standard of care in preemtping overdrainage associated with ventriculoperitoneal shunting for hydrocephalus. OBJECTIVE: We aimed to provide comparative data of four combinations of two ASDs of different working principles in combination with two DP valves in an in vitro model in order to achieve a better understanding of the flow characteristics and potential clinical application. METHODS: We analyzed the flow performance of four possible combinations of two DP valves (CHPV [HM]; proGAV 2.0[PG]) in combination with either a gravity-regulated (Shuntassistant [SA]) or a flow-regulated (SiphonGuard [SG]) ASD in an in vitro setup. A DP between 4 and 60 cmH2O was generated, and the specific flow characteristics were measured. In addition, the two combinations with gravity-regulated ASDs were measured in defined spatial positions. RESULTS: Flow characteristics of the SA combinations corresponded to the DP in linear fashion and to the spatial position. Flow characteristics of the SG combinations were dependent upon the DP in a non-linear fashion and independent of the spatial position. Highest mean flow rate of the PG-SG- (HM-SG-) combination was 1.41 ± 0.24 ml/min (1.16 ± 0.06 ml/min). The mean flow rates sharply decreased with increasing inflow pressure and subsequently increased slowly up to 0.82 ± 0.26 ml/min (0.77 ± 0.08 ml/min). CONCLUSION: All tested device combinations were able to control hydrostatic effect and prevent consecutive excessive flow, to varying degrees. However, significant differences in flow characteristics can be seen, which might be relevant for their clinical application.


Assuntos
Derivações do Líquido Cefalorraquidiano/instrumentação , Desenho de Equipamento , Hidrocefalia/cirurgia , Teste de Materiais , Derivações do Líquido Cefalorraquidiano/efeitos adversos , Gravitação , Humanos
5.
Acta Neurochir (Wien) ; 162(10): 2421-2430, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32779025

RESUMO

OBJECTIVE: Adjustable differential pressure (DP) valves in combination with fixed anti-siphon devices are currently a popular combination in counteracting the effects of cerebrospinal fluid overdrainage following implantation of a ventriculoperitoneal shunt system. The study examined the flow performance of three DP valves in successive combination with an anti-siphon device in an in vitro shunt laboratory with and without vertical motion. METHODS: We analyzed three DP valves (Codman Hakim Medos programmable valve [HM], Codman CertasPlus [CP], and Miethke proGAV [PG], in combination with either Codman SiphonGuard [SG] or Miethke ShuntAssistant [SA]), resulting in the evaluation of six different valve combinations. Defined DP conditions between 4 and 40 cm H2O within a simulated shunt system were generated and the specific flow characteristics were measured. In addition, combinations with SA, which is a gravity-dependent valve, were measured in defined spatial positions (90°, 60°). All device combinations were tested during vertical motion with movement frequencies of 2, 3, and 4 Hz. RESULTS: All valve combinations effectively counteracted the siphon effect in relation to the chosen DP. Angulation-related flow changes were similar in the three combinations of DP valve and SA in the 60° and 90° position. In CP-SA and PG-SA, repeated vertical movement at 2, 3, and 4 Hz led to significant increase in flow, whereas in HM-SA, constant increase was seen at 4 Hz only (flow change at 4Hz, DP 40 cm H2O: PG (opening pressure 4 cm H2O) 90°: 0.95 ml/min, 60°: 0.71 ml/min; HM (opening pressure 4 cm H2O) 90°: 0.66 ml/min, 60°: 0.41 ml/min; CP (PL 2) 90°: 0.94 ml/min, 60°: 0.79 ml/min; p < 0.01); however, HM-SA showed relevant motion-induced flow already at low DPs (0.85 ml/min, DP 4 cm H2O). In combinations of DP valve with SG, increase of flow was far less pronounced and even led to significant reduction of flow in certain constellations. Maximum overall flow increase was 0.46 ± 0.04 ml/min with a HM (opening pressure 12 cm H2O) at 2 Hz and a DP of 10 cm H2O, whereas maximum flow decrease was 1.12 ± 0.08 with a PG (opening pressure 4 cm H2O) at 3 Hz and a DP of 10 cmH2O. CONCLUSION: In an experimental setup, all valve combinations effectively counteracted the siphon effect in the vertical position according to their added resistance. Motion-induced increased flow was consistently demonstrated in combinations of DP valve and SA. The combination of HM and SA especially showed relevant motion-induced flow already at low DPs. In combinations of DP and SG, the pattern of the motion induced flow was more inconsistent and motion even led to significant flow reduction, predominantly at DPs of 10 and 20 cmH2O.


Assuntos
Hidrocefalia/cirurgia , Derivação Ventriculoperitoneal/instrumentação , Gravitação , Humanos , Movimento (Física) , Próteses e Implantes/efeitos adversos , Próteses e Implantes/normas
6.
Nervenarzt ; 89(6): 648-657, 2018 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-29679126

RESUMO

BACKGROUND: Adult spinal deformity (ASD) is mostly a progressive disease which usually leads to chronic pain. Due to increased prevalence in older people many patients suffer from comorbidities, which make conservative and surgical treatment even more complex. OBJECTIVE: This article provides an overview on the current conservative and surgical treatment options. MATERIAL AND METHODS: An extensive literature search was carried out via Medline plus an additional evaluation of the authors' personal experiences was performed. RESULTS: The current conservative and surgical treatments are outlined and potential risk factors and predictors which may lead to inferior clinical outcome are discussed. CONCLUSION: Patients for whom even conservative treatment leads to success should be identified earlier and better. The surgical treatment ranges from minimally invasive decompression to multilevel fusions. Complications in large corrective interventions can be substantial but if the indications are correctly assessed, such complex surgical treatment has excellent clinical results in terms of pain and quality of life.


Assuntos
Procedimentos Neurocirúrgicos , Doenças da Coluna Vertebral , Descompressão Cirúrgica , Humanos , Dor , Qualidade de Vida , Doenças da Coluna Vertebral/cirurgia , Resultado do Tratamento
7.
Nervenarzt ; 89(6): 639-647, 2018 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-29679129

RESUMO

BACKGROUND: Degenerative diseases of the lumbar spine and associated lower back pain represent a major epidemiological and health-related economic challenge. A distinction is made between specific and unspecific lower back pain. In specific lower back pain lumbar disc herniation and spinal canal stenosis with or without associated segment instability are among the most frequent pathologies. Diverse conservative and operative strategies for treatment of these diseases are available. OBJECTIVES: The aim of this article is to present an overview of current data and an evidence-based assessment of the possible forms of treatment. MATERIAL AND METHODS: An extensive literature search was carried out via Medline plus an additional evaluation of the authors' personal experiences. RESULTS: Conservative and surgical treatment represent efficient treatment options for degenerative diseases of the lumbar spine. Surgical treatment of lumbar disc herniation shows slight advantages compared to conservative treatment consisting of faster recovery of neurological deficits and a faster restitution of pain control. Surgical decompression is superior to conservative measures for the treatment of spinal canal stenosis and degenerative spondylolisthesis. In this scenario conservative treatment represents an important supporting measure for surgical treatment in order to improve the mobility of patients and the outcome of surgical treatment. CONCLUSION: The treatment of specific lower back pain due to degenerative lumbar pathologies represents an interdisciplinary challenge, requiring both conservative and surgical treatment strategies in a synergistic treatment concept in order to achieve the best results for patients.


Assuntos
Vértebras Lombares , Doenças da Coluna Vertebral , Humanos , Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Doenças da Coluna Vertebral/patologia , Doenças da Coluna Vertebral/cirurgia , Estenose Espinal/cirurgia , Espondilolistese
8.
BMC Urol ; 17(1): 46, 2017 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-28629351

RESUMO

BACKGROUND: Urological diseases and their treatment may negatively influence continence, potency, and health-related quality of life (HRQOL). Although current guidelines recommend HRQOL assessment in clinical urology, specific guidance on how to assess HRQOL is frequently absent. We evaluated whether and how urologists assess HRQOL and how they determine its practicality. METHODS: A random sample of 4500 (from 5200 identified German urologists) was drawn and invited to participate in a postal survey (an initial letter followed by one reminder after six weeks). The questionnaire included questions on whether and how HRQOL is assessed, general attitudes towards the concept of HRQOL, and socio-demographics. Due to the exploratory character of the study we produced mainly descriptive statistics. Chi2-tests and logistic regression were used for subgroup-analysis. RESULTS: 1557 urologists (85% male, with a mean age of 49 yrs.) participated. Most of them (87%) considered HRQOL assessment as 'important' in daily work, while only 7% reported not assessing HRQOL. Patients with prostate carcinoma, incontinence, pain, and benign prostate hyperplasia were the main target groups for HRQOL assessment. The primary aim of HRQOL assessment was to support treatment decisions, monitor patients, and produce a 'baseline measurement'. Two-thirds of urologists used questionnaires and interviews to evaluate HRQOL and one-quarter assessed HRQOL by asking: 'How are you?'. The main barriers to HRQOL assessment were anticipated questionnaire costs (77%), extensive questionnaire length (52%), and complex analysis (51%). CONCLUSIONS: The majority of German urologists assess HRQOL as part of their clinical routine. However, knowledge of HRQOL assessment, analysis, and interpretation seems to be limited in this group. Therefore, urologists may benefit from a targeted education program. TRIAL REGISTRATION: The clinical trial was registered with the code VfD_13_003629 at the German Healthcare Research Registry ( www.versorgungsforschung-deutschland.de ).


Assuntos
Qualidade de Vida/psicologia , Doenças Urológicas/psicologia , Urologistas/psicologia , Urologia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais/métodos , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Urológicas/diagnóstico , Doenças Urológicas/epidemiologia
9.
Neurosurg Rev ; 40(4): 655-661, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28185018

RESUMO

Decompressive hemicraniectomy (DH) plus duroplasty was demonstrated to be effective for treating critically elevated intracranial pressure (ICP). In order to shorten operation time and to avoid the use of autologous or heterologous material, durotomy has been introduced as an alternative to duroplasty. Only limited data is available on the effect of DH and durotomy on the increased ICP in traumatic brain injury (TBI). Therefore, we collected consecutive intraoperative ICP readings during the different steps of DH and durotomy in TBI patients. Eighteen patients with TBI and uncontrollable ICP increase (measured by either an intraparenchymal or an intraventricular ICP probe) underwent DH and durotomy. ICP readings as well as mean arterial blood pressure (MAP) and arterial PCO2 were obtained during defined stages of the operation. Surgical complications of the durotomy itself and of cranioplasty after 3 months were recorded. The outcome was assessed prior to cranioplasty using the Glasgow Outcome Scale (GOS). ICP dropped significantly during surgery from a mean of 41 ( ± 16.2) mmHg at the beginning to a mean of 11.8 ( ± 7.5) mmHg at the end (p ≤ 0.001). A first significant ICP-decrease to a mean of 18 ( ± 10.8) mmHg (p ≤ 0.001) was detected after removal of the bone flap, and a second significant ICP-decrease to a mean of 10.6 ( ± 5.3) mmHg (p < 0.001) during durotomy. The mean operation time was 115.3 min ( ± 49.6). Five patients (28%) died; seven patients (39%) had a good outcome (GOS 5). There were no relevant complications associated to durotomy. Durotomy after DH is a safe and straightforward procedure, which significantly lowers critically increased ICP in patients with TBI. Although no graft is used, dural preparation for cranioplasty at 3 months is easily possible.


Assuntos
Lesões Encefálicas Traumáticas/cirurgia , Craniotomia , Descompressão Cirúrgica , Hipertensão Intracraniana/cirurgia , Adulto , Idoso , Lesões Encefálicas Traumáticas/complicações , Lesões Encefálicas Traumáticas/fisiopatologia , Dura-Máter/cirurgia , Feminino , Escala de Resultado de Glasgow , Humanos , Hipertensão Intracraniana/diagnóstico , Hipertensão Intracraniana/etiologia , Pressão Intracraniana/fisiologia , Masculino , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos , Retalhos Cirúrgicos , Resultado do Tratamento
10.
Acta Neurochir (Wien) ; 159(7): 1321-1324, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28516363

RESUMO

Posterior reversible encephalopathy syndrome (PRES) is thought to result from endothelial dysfunction and breakdown of the blood-brain barrier with subsequent vasogenic edema. Abrupt hypertension has been identified as one of its risk factors. We present a rare case of PRES in the anterior circulation with sudden onset of left hemiparesis and rapid neurological deterioration on the basis of hypertensive crisis. Due to refractory intracranial hypertension, the patient required emergent right decompressive craniectomy. Further investigations, including a biopsy, revealed an atypical form of PRES. This case illustrates the importance of aggressive medical and early surgical management to prevent permanent neurological deficits.


Assuntos
Descompressão Cirúrgica/efeitos adversos , Pressão Intracraniana , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Adulto , Barreira Hematoencefálica/patologia , Feminino , Humanos , Síndrome da Leucoencefalopatia Posterior/cirurgia , Complicações Pós-Operatórias , Fatores de Risco
11.
Neurosurg Rev ; 38(1): 191-5; discussion 195, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25242202

RESUMO

Studies on immediate failed back surgery syndrome (iFBSS) following lumbar microdiscectomy are rare. Our aim is to describe the incidence and the causes of these immediate failures to define the value of radiological imaging for identification of the underlying pathology and to propose a management algorithm. We defined iFBSS as persistence, deterioration or recurrence (during hospital stay) of radicular pain and/or sensorimotor deficits and/or sphincter dysfunction after microdiscectomy, which was uneventful from the surgeon's perspective. The medical records of 1546 patients undergoing discectomy for mediolateral lumbar disc herniations were screened for iFBSS. The pre- and postoperative imaging, surgical records, therapy and outcome of patients with iFBSS were reviewed. Forty-four of 1546 patients (2.8%) with iFBSS were identified. All patients underwent reoperation. Overseen disc material/re-herniation (n = 22), epidural hematoma (n = 6), inadequate decompression of accompanying recessal stenosis (n = 2) and dural tear with fascicle herniation (n = 1) were found to be causative. In 13 patients, who revealed no clear pathology intraoperatively, we diagnosed a battered root syndrome (nerve root swelling due to excessive surgical manipulation). The correct diagnosis could be established by neuroradiological imaging in 25 of 43 radiologically investigated patients (57%). In our study, the radiological workup was of limited value for the correct differentiation of the various aetiologies of iFBSS. Therefore, the authors believe that the treatment strategy should strongly rely on the clinical presentation. To avoid unnecessary surgery in cases of battered root syndrome, we propose to proceed to reoperation only in patients with new or persistent radiculopathy despite adequate antiedematous medical therapy.


Assuntos
Discotomia , Deslocamento do Disco Intervertebral/epidemiologia , Vértebras Lombares/cirurgia , Adulto , Idoso , Descompressão Cirúrgica/métodos , Feminino , Humanos , Incidência , Deslocamento do Disco Intervertebral/complicações , Masculino , Pessoa de Meia-Idade , Reoperação , Resultado do Tratamento
12.
Neurosurg Rev ; 38(1): 89-98; discussion 98-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25323095

RESUMO

Chordomas are rare, locally aggressive malignancies that often exhibit an insidious natural history and are difficult to eradicate. Surgery and radiotherapy are the treatment mainstays of chordoma, but the chance of local recurrence remains high. Reports of receptor tyrosine kinase (RTK) expression in chordoma suggest that these tumors may respond to kinase inhibitor therapy. Currently, there are no effective chemotherapeutic protocols for chordoma. A tissue microarray containing 74 tumor specimens from primary chordoma patients and 71 from their recurrent tumors for a total of 145 tumor specimens was immunohistochemically analyzed for expression of a number of proteins involved in signal transduction from RTKs. Platelet-derived growth factor receptor-α (PDGFR-α), epidermal growth factor receptor (EGFR), c-Met, and CD-34 were detected in 100, 92, 100, and 59% of cases, respectively. PDGFR-α and c-Met staining was of moderate to strong intensity in all cases. In contrast, total EGFR staining was variable; weak staining was detected in 10 cases. Our results contribute to the understanding of the expression of RTKs in skull base chordomas and support the development of targeted therapies that inhibit RTKs, which may have a synergistic effect for chemotherapy in patients. There were statistically significant correlations between the expression of PDGFR-α, c-Met, and EGFR and disease-free survival. The results nonetheless suggest that chordomas may respond to RTK inhibitors or modulators of other downstream signaling.


Assuntos
Cordoma/metabolismo , Receptores ErbB/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Neoplasias da Base do Crânio/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Cordoma/patologia , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica/métodos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Adulto Jovem
13.
Neurosurg Rev ; 37(1): 79-88, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23999886

RESUMO

Chordomas are locally invasive tumors that have a tendency to relapse despite optimal treatment. Specific biological markers might be used to describe their behavior. There is currently no agreement regarding the best way to manage intracranial chordomas. We studied the expression of vascular endothelial growth factor receptor 2 (VEGFR-2), inducible nitric oxide synthase (iNOS), and Ki-M1P in 145 paraffin-embedded tumors. The purpose of our study was to determine: (a) the role of potent angiogenic factors VEGFR-2 and iNOS and their relationship to each other in skull base chordoma and (b) the role of monocytes/macrophages as a potential iNOS source in the angiogenic process. A series of 74 chordoma patients for a total of 145 lesions (including 71 recurrent lesions) and 10 specimens from embryonic notochord were investigated for the expression of iNOS, VEGFR-2, Ki-M1P, and CD-34 using immunohistochemistry. In the majority of the chordomas, correlations were found between iNOS and the immunoreactivity of Ki-M1P (r = 0.5303, P < 0.0001). Furthermore, the expressions of Ki-M1P was correlated with VEGFR-2 (r = 0.4181, P < 0.0001). Our results indicate that chordomas may respond to receptor tyrosine kinase inhibitors such as VEGFR-2 or modulators of other downstream signaling molecules. The future of VEGFR-2 and iNOS inhibitors as therapeutic agents in the treatment of chordoma will be clearer over the next years as results of the current clinical trials become available and as the factors regulating angiogenesis and the interactions between these factors are elucidated. However, appropriate functional experiments remain to be conducted to prove such a hypothesis.


Assuntos
Anticorpos Monoclonais/biossíntese , Cordoma/metabolismo , Óxido Nítrico Sintase Tipo II/biossíntese , Neoplasias da Base do Crânio/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/biossíntese , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/imunologia , Biomarcadores Tumorais/análise , Cordoma/patologia , Estudos de Coortes , Feminino , Humanos , Imuno-Histoquímica , Macrófagos/metabolismo , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Monócitos/metabolismo , Recidiva Local de Neoplasia , Neovascularização Patológica/patologia , Infiltração de Neutrófilos , Neoplasias da Base do Crânio/patologia , Adulto Jovem
15.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38206100

RESUMO

The imaging heavy ion beam probe (i-HIBP) diagnostic has been successfully commissioned at ASDEX Upgrade. The i-HIBP injects a primary neutral beam into the plasma, where it is ionized, leading to a fan of secondary (charged) beams. These are deflected by the magnetic field of the tokamak and collected by a scintillator detector, generating a strike-line light pattern that encodes information on the density, electrostatic potential, and magnetic field of the plasma edge. The first measurements have been made, demonstrating the proof-of-principle of this diagnostic technique. A primary beam of 85/87Rb has been used with energies ranging between 60 and 72 keV and extracted currents up to 1.5 mA. The first signals have been obtained in experiments covering a wide range of parameter spaces, with plasma currents (Ip) between 0.2 and 0.8 MA and on-axis toroidal magnetic field (Bt) between 1.9 and 2.7 T. Low densities appear to be critical for the performance of the diagnostic, as signals are typically observed only when the line integrated density is below 2.0-3.0 × 1019 m-2 in the central interferometer chord, depending on the plasma shape. The strike line moves as expected when Ip is ramped, indicating that current measurements are possible. Additionally, clear dynamics in the intensity of the strike line are often observed, which might be linked to changes in the edge profile structure. However, the signal-to-background ratio of the signals is hampered by stray light, and the image guide degradation is due to neutron irradiation. Finally, simulations have been carried out to investigate the sensitivity of the expected signals to plasma density and temperature. The results are in qualitative agreement with the experimental observations, suggesting that the diagnostic is almost insensitive to fluctuations in the temperature profile, while the signal level is highly determined by the density profile due to the beam attenuation.

17.
Rev Sci Instrum ; 94(4)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38081276

RESUMO

A new shattered pellet injection system was designed and built to perform disruption mitigation experiments on ASDEX Upgrade. The system can inject pellets with diameters of 1, 2, 4, or 8 mm with variable lengths over a range of L/D ratios of ∼0.5-1.5. By using helium or deuterium as propellant gas, the pellets can be accelerated to speeds between 60 and 750 m/s. The velocity range slightly depends on the pellet mass. The injection system is capable of preparing three pellets in separate barrels at the same time. Once accelerated by the propellant gas pulse, the pellets travel through one of three parallel flight tubes. Each flight tube is separated into three sections with increasing diameters of 12, 14, and 16 mm. Two gaps between the sections allow for removal of the propellant gas by expansion into two separate expansions tanks (0.3 and 0.035 m3), pellet observation in the first gap and the torus gate valve in the second. Each flight tube end is equipped with an exchangeable shatter head with different shatter angles, square or circular cross-section, and different lengths. The gas preparation and control systems allow highly automated pellet generation for precision of the pellet composition and an excellent reproducibility of shattered pellet experiments.

18.
Clin Neurol Neurosurg ; 212: 107089, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34902753

RESUMO

OBJECTIVE: Traumatic brain injury (TBI) constitutes a major cause of trauma-related disability and mortality. The epidemiology and implications of associated cranial nerve injuries (CNI) in moderate to severe TBI are largely unknown. We aimed to determine the incidence of CNI in a large European cohort of TBI patients as well as clinical differences between TBI cases with and without concomitant CNI (CNI vs. control group) by means of a multinational trauma registry. METHODS: The TraumaRegister DGU® was evaluated for trauma patients with head injuries ≥ 2 Abbreviated Injury Scale, who had to be treated on intensive care units after emergency admission to European hospitals between 2008 and 2017. CNI and control cases were compared with respect to demographic, clinical, and outcome variables. RESULTS: 1.0% (946 of 91,196) of TBI patients presented with additional CNI. On average, CNI patients were younger than control cases (44.3 ± 20.6 vs. 51.8 ± 23.0 years) but did not differ regarding sex distribution (CNI 69.4% males vs. control 69.1%). Traffic accidents were encountered more frequently in CNI cases (52.3% vs. 46.7%; p < 0.001; chi-squared test) and falls more commonly in the control group (45.2% vs. 37.1%; p < 0.001). CNI patients suffered more frequently from concomitant face injuries (28.2% vs. 17.5%; p < 0.001) and skull base fractures (51.0% vs. 23.5%; p < 0.001). Despite similar mean Injury Severity Score (CNI 21.8 ± 11.3; control 21.1 ± 11.7) and Glasgow Coma Scale score (CNI 10.9 ± 4.2, control 11.1 ± 4.4), there was a considerably higher proportion of anisocoria in CNI patients (20.1% vs. 11.2%; p < 0.001). Following primary treatment, 50.8% of CNI and 35.5% of control cases showed moderate to severe disability (Glasgow Outcome Scale score 3-4; p < 0.001). CONCLUSION: CNI rarely occur in the context of TBI. When present, they indicate a higher likelihood of functional impairment following primary care and complicating skull base fractures should be suspected.


Assuntos
Lesões Encefálicas Traumáticas/epidemiologia , Traumatismos dos Nervos Cranianos/epidemiologia , Sistema de Registros/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Comorbidade , Europa (Continente)/epidemiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Índices de Gravidade do Trauma , Adulto Jovem
19.
Phys Rev Lett ; 106(12): 125002, 2011 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-21517319

RESUMO

Magnetically confined plasmas in the high confinement regime are regularly subjected to relaxation oscillations, termed edge localized modes (ELMs), leading to large transport events. Present ELM theories rely on a combined effect of edge current and the edge pressure gradients which result in intermediate mode number (n≅10-15) structures (filaments) localized in the perpendicular plane and extended along the field lines. By detailed localized measurements of the magnetic field perturbation associated to type-I ELM filaments, it is shown that these filaments carry a substantial current.

20.
Minim Invasive Neurosurg ; 54(2): 55-60, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21523649

RESUMO

BACKGROUND: Tumors originating from or involving the petrous apex are considered to be an operative challenge due to their deep location and close relationship to critical neural and vascular structures. Extensive skull base approaches have been developed to deal with these lesions. The purpose of this study is to review an institutional series of 57 petrous apex tumors, to report our operative experiences and to address the usefulness and limits of standard approaches. MATERIAL AND METHODS: 57 patients (22 men, 35 women) with petrous apex tumors were treated microsurgically. We analyzed the type of surgical approach, histological diagnoses, pre- and postoperative clinical findings, diagnostic imaging and surgery-associated complications. RESULTS: According to the location and its predominant extension, a retromastoid approach (n=27), subtemporal approach (n=18), subtemporal/anterosigmoid approach (n=5), transnasal-transsphenoidal approach (n=2), pterional approach (n=2) or a subtemporal/retrosigmoid approach, biphasic approach (subtemporal and pterional), transmastoidal approach (n=1 each) was chosen. In the majority of cases, histological analysis revealed a meningeoma (n=31) or neurinoma (n=7). A total tumor resection was accomplished in 37 patients (64.9%). New permanent neurological deficits, mainly cranial nerve palsies, were found in 18 (31.6%), transient deficits in 5 patients (9.6%). Postoperative improvements of neurological deficits were observed in 17 patients (29.8%), and the neurological status remained unchanged in 17 patients (32.7%). CONCLUSION: Complete resection of petrous apex tumors using standard neurosurgical approaches without permanent surgery-associated neurological deficits is achievable in the majority of cases.


Assuntos
Meningioma/cirurgia , Neurilemoma/cirurgia , Osso Petroso/cirurgia , Neoplasias Cranianas/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Neoplasias Meníngeas/diagnóstico por imagem , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/cirurgia , Meningioma/diagnóstico por imagem , Meningioma/patologia , Pessoa de Meia-Idade , Neurilemoma/diagnóstico por imagem , Neurilemoma/patologia , Procedimentos Neurocirúrgicos , Osso Petroso/diagnóstico por imagem , Osso Petroso/patologia , Radiografia , Estudos Retrospectivos , Neoplasias Cranianas/diagnóstico por imagem , Neoplasias Cranianas/patologia , Resultado do Tratamento
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