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1.
World Neurosurg ; 184: e754-e764, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38350598

RESUMEN

BACKGROUND: With continued evolution in stereotactic techniques and an expanding armamentarium of surgical therapeutic options, non-craniotomy stereotactic procedures in neuro-oncology are becoming increasingly complex, often requiring multi-trajectory approaches. Here we demonstrate that the ClearPoint SmartFrame Array (Solana Beach, California, USA), a second-generation magnetic resonance imaging-compatible stereotactic frame, supports such non-craniotomy, multi-trajectory (NCMT) stereotactic procedures. METHODS: We previously published case reports demonstrating the feasibility of NCMT through the ClearPoint SmartFrame Array. Here we prospectively followed the next 10 consecutive patients who underwent such multi-trajectory procedures to further establish procedural safety and clinical utility. RESULTS: Ten patients underwent complex, multi-trajectory stereotactic procedures, including combinations of needle biopsy ± cyst drainage and laser interstitial thermal therapy targeting geographically distinct regions of neoplastic lesions under the same anesthetic event. The median maximal radial error of stereotaxis was 1.0 mm. In all cases, definitive diagnosis was achieved, and >90% of the intended targets were ablated. The average stereotaxis time for the multi-trajectory procedure was 119 ± 22.2 minutes, comparing favorably to our previously published results of single-trajectory procedures (80 ± 9.59 minutes, P = 0.125). There were no procedural complications. Post-procedure, the neurologic condition of 1 patient improved, while the remaining 9 patients remained stable. All patients were discharged home, with a median hospital stay of 1 day (range: 1-12 days). With a median follow-up of 376 days (range: 155-1438 days), there were no 30-day readmissions or wound complications. CONCLUSIONS: Geographically distinct regions of brain cancer can be safely and accurately accessed through the ClearPoint Array frame in NCMT stereotactic procedures.


Asunto(s)
Neoplasias Encefálicas , Terapia por Láser , Humanos , Terapia por Láser/métodos , Técnicas Estereotáxicas , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Procedimientos Neuroquirúrgicos/métodos , Imagen por Resonancia Magnética/métodos
2.
Transplantation ; 108(3): 777-786, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37899481

RESUMEN

BACKGROUND: Chronic lung allograft dysfunction (CLAD) is the leading cause of death beyond the first year after lung transplantation. The development of donor-specific antibodies (DSA) is a recognized risk factor for CLAD. Based on experience in kidney transplantation, we hypothesized that belatacept, a selective T-cell costimulatory blocker, would reduce the incidence of DSA after lung transplantation, which may ameliorate the risk of CLAD. METHODS: We conducted a pilot randomized controlled trial (RCT) at 2 sites to assess the feasibility and inform the design of a large-scale RCT. All participants were treated with rabbit antithymocyte globulin for induction immunosuppression. Participants in the control arm were treated with tacrolimus, mycophenolate mofetil, and prednisone, and participants in the belatacept arm were treated with tacrolimus, belatacept, and prednisone through day 89 after transplant then converted to belatacept, mycophenolate mofetil, and prednisone for the remainder of year 1. RESULTS: After randomizing 27 participants, 3 in the belatacept arm died compared with none in the control arm. As a result, we stopped enrollment and treatment with belatacept, and all participants were treated with standard-of-care immunosuppression. Overall, 6 participants in the belatacept arm died compared with none in the control arm (log rank P = 0.008). We did not observe any differences in the incidence of DSA, acute cellular rejection, antibody-mediated rejection, CLAD, or infections between the 2 groups. CONCLUSIONS: We conclude that the investigational regimen used in this pilot RCT is associated with increased mortality after lung transplantation.


Asunto(s)
Trasplante de Pulmón , Tacrolimus , Humanos , Abatacept/uso terapéutico , Tacrolimus/efectos adversos , Ácido Micofenólico/uso terapéutico , Prednisona/uso terapéutico , Proyectos Piloto , Inmunosupresores/efectos adversos , Terapia de Inmunosupresión , Anticuerpos , Trasplante de Pulmón/efectos adversos , Rechazo de Injerto/prevención & control , Rechazo de Injerto/etiología , Supervivencia de Injerto
3.
Lancet Respir Med ; 11(9): 791-803, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37348524

RESUMEN

BACKGROUND: There is a clinical need for therapeutics for COVID-19 patients with acute hypoxemic respiratory failure whose 60-day mortality remains at 30-50%. Aviptadil, a lung-protective neuropeptide, and remdesivir, a nucleotide prodrug of an adenosine analog, were compared with placebo among patients with COVID-19 acute hypoxaemic respiratory failure. METHODS: TESICO was a randomised trial of aviptadil and remdesivir versus placebo at 28 sites in the USA. Hospitalised adult patients were eligible for the study if they had acute hypoxaemic respiratory failure due to confirmed SARS-CoV-2 infection and were within 4 days of the onset of respiratory failure. Participants could be randomly assigned to both study treatments in a 2 × 2 factorial design or to just one of the agents. Participants were randomly assigned with a web-based application. For each site, randomisation was stratified by disease severity (high-flow nasal oxygen or non-invasive ventilation vs invasive mechanical ventilation or extracorporeal membrane oxygenation [ECMO]), and four strata were defined by remdesivir and aviptadil eligibility, as follows: (1) eligible for randomisation to aviptadil and remdesivir in the 2 × 2 factorial design; participants were equally randomly assigned (1:1:1:1) to intravenous aviptadil plus remdesivir, aviptadil plus remdesivir matched placebo, aviptadil matched placebo plus remdesvir, or aviptadil placebo plus remdesivir placebo; (2) eligible for randomisation to aviptadil only because remdesivir was started before randomisation; (3) eligible for randomisation to aviptadil only because remdesivir was contraindicated; and (4) eligible for randomisation to remdesivir only because aviptadil was contraindicated. For participants in strata 2-4, randomisation was 1:1 to the active agent or matched placebo. Aviptadil was administered as a daily 12-h infusion for 3 days, targeting 600 pmol/kg on infusion day 1, 1200 pmol/kg on day 2, and 1800 pmol/kg on day 3. Remdesivir was administered as a 200 mg loading dose, followed by 100 mg daily maintenance doses for up to a 10-day total course. For participants assigned to placebo for either agent, matched saline placebo was administered in identical volumes. For both treatment comparisons, the primary outcome, assessed at day 90, was a six-category ordinal outcome: (1) at home (defined as the type of residence before hospitalisation) and off oxygen (recovered) for at least 77 days, (2) at home and off oxygen for 49-76 days, (3) at home and off oxygen for 1-48 days, (4) not hospitalised but either on supplemental oxygen or not at home, (5) hospitalised or in hospice care, or (6) dead. Mortality up to day 90 was a key secondary outcome. The independent data and safety monitoring board recommended stopping the aviptadil trial on May 25, 2022, for futility. On June 9, 2022, the sponsor stopped the trial of remdesivir due to slow enrolment. The trial is registered with ClinicalTrials.gov, NCT04843761. FINDINGS: Between April 21, 2021, and May 24, 2022, we enrolled 473 participants in the study. For the aviptadil comparison, 471 participants were randomly assigned to aviptadil or matched placebo. The modified intention-to-treat population comprised 461 participants who received at least a partial infusion of aviptadil (231 participants) or aviptadil matched placebo (230 participants). For the remdesivir comparison, 87 participants were randomly assigned to remdesivir or matched placebo and all received some infusion of remdesivir (44 participants) or remdesivir matched placebo (43 participants). 85 participants were included in the modified intention-to-treat analyses for both agents (ie, those enrolled in the 2 x 2 factorial). For the aviptadil versus placebo comparison, the median age was 57 years (IQR 46-66), 178 (39%) of 461 participants were female, and 246 (53%) were Black, Hispanic, Asian or other (vs 215 [47%] White participants). 431 (94%) of 461 participants were in an intensive care unit at baseline, with 271 (59%) receiving high-flow nasal oxygen or non-invasive ventiliation, 185 (40%) receiving invasive mechanical ventilation, and five (1%) receiving ECMO. The odds ratio (OR) for being in a better category of the primary efficacy endpoint for aviptadil versus placebo at day 90, from a model stratified by baseline disease severity, was 1·11 (95% CI 0·80-1·55; p=0·54). Up to day 90, 86 participants in the aviptadil group and 83 in the placebo group died. The cumulative percentage who died up to day 90 was 38% in the aviptadil group and 36% in the placebo group (hazard ratio 1·04, 95% CI 0·77-1·41; p=0·78). The primary safety outcome of death, serious adverse events, organ failure, serious infection, or grade 3 or 4 adverse events up to day 5 occurred in 146 (63%) of 231 patients in the aviptadil group compared with 129 (56%) of 230 participants in the placebo group (OR 1·40, 95% CI 0·94-2·08; p=0·10). INTERPRETATION: Among patients with COVID-19-associated acute hypoxaemic respiratory failure, aviptadil did not significantly improve clinical outcomes up to day 90 when compared with placebo. The smaller than planned sample size for the remdesivir trial did not permit definitive conclusions regarding safety or efficacy. FUNDING: National Institutes of Health.


Asunto(s)
COVID-19 , Insuficiencia Respiratoria , Adulto , Humanos , Femenino , Persona de Mediana Edad , Masculino , COVID-19/complicaciones , SARS-CoV-2 , Resultado del Tratamiento , Tratamiento Farmacológico de COVID-19 , Insuficiencia Respiratoria/tratamiento farmacológico , Insuficiencia Respiratoria/etiología , Oxígeno
4.
J Neurosurg Case Lessons ; 5(2)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36624633

RESUMEN

BACKGROUND: Current technologies that support stereotactic laser ablation (SLA) of geographically distinct lesions require placement of multiple bolts or time-consuming, intertrajectory adjustments. OBSERVATIONS: Two geographically distinct nodular lesions were safely biopsied and laser ablated in a 62-year-old woman with recurrent glioblastoma using the ClearPoint Array frame, a novel magnetic resonance imaging-compatible stereotactic frame designed to support independent parallel trajectories without intertrajectory frame adjustment. LESSONS: Here, the authors provide a proof-of-principle case report demonstrating that geographically distinct lesions can be safely biopsied and ablated through parallel trajectories supported by the ClearPoint Array frame without intertrajectory adjustment.

5.
Nat Mater ; 21(12): 1352-1356, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36138146

RESUMEN

Conductivities are key material parameters that govern various types of transport (electronic charge, spin, heat and so on) driven by thermodynamic forces. Magnons, the elementary excitations of the magnetic order, flow under the gradient of a magnon chemical potential1-3 in proportion to a magnon (spin) conductivity. The magnetic insulator yttrium iron garnet is the material of choice for efficient magnon spin transport. Here we report a giant magnon conductivity in thin yttrium iron garnet films with thicknesses down to 3.7 nm when the number of occupied two-dimensional subbands is reduced from a large number to a few, which corresponds to a transition from three-dimensional to two-dimensional magnon transport. We extract a two-dimensional magnon spin conductivity around 1 S at room temperature, comparable to the (electronic) conductivity of the high-mobility two-dimensional electron gas in GaAs quantum wells at millikelvin temperatures4. Such high conductivities offer opportunities to develop low-dissipation magnon-based spintronic devices.

6.
Sci Rep ; 12(1): 7246, 2022 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-35508481

RESUMEN

Nonlinear self-phase modulation is a universal phenomenon responsible, for example, for the formation of propagating dynamic solitons. It has been reported for waves of different physical nature. However its direct experimental observation for spin waves has been challenging. Here we show that exceptionally strong phase modulation can be achieved for spin waves in microscopic waveguides fabricated from nanometer-thick films of magnetic insulator, which support propagation of spin waves with large amplitudes corresponding to angles of magnetization precession exceeding 10°. At these amplitudes, the nonstationary nonlinear dynamic response of the spin system causes an extreme broadening of the spectrum of spin-wave pulses resulting in a strong spatial variation of the spin-wave wavelength and a temporal variation of the spin-wave phase across the pulse. Our findings demonstrate great complexity of nonlinear wave processes in microscopic magnetic structures and importance of their understanding for technical applications of spin waves in integrated devices.

7.
Turk J Gastroenterol ; 32(10): 808-818, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34787085

RESUMEN

BACKGROUND: The aim of the study was to examine the impact of diagnostic status (i.e., having a clinical diagnosis of irritable bowel syndrome (IBS) or being symptomatic but undiagnosed on quality of life (QoL)). We also examined whether the relationships between QoL and variables such as symptom frequency, pain catastrophizing, visceral sensitivity, and psychological distress are moderated by diagnostic status. METHODS: The online sample comprised 404 participants (Mage = 33.59, SD = 12.43), of which 98 had been diagnosed with IBS and 306 were symptomatic but undiagnosed. RESULTS: The findings suggest that even after adjusting for symptom frequency, those diagnosed with IBS experience poorer QoL, relative to those without a diagnosis. Moreover, there was evidence that the relationship between specific QoL domains (namely, sex, food avoidance, and health worry) and psychological variables (namely, pain catastrophizing, and depression) was moderated by diagnostic status. CONCLUSION: The results indicate that diagnostic status in relation to IBS has psychological implications for QoL outcomes distinct from symptom frequency, age, and gender. This highlights a substantial gap in our current understanding of how a diagnosis of IBS can impact the lives of those suffering from IBS symptomology and calls into question the intended purpose of diagnosis.


Asunto(s)
Síndrome del Colon Irritable , Calidad de Vida , Humanos , Síndrome del Colon Irritable/diagnóstico
8.
Epilepsy Res ; 176: 106725, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34304018

RESUMEN

OBJECTIVE: High volume surgical epilepsy centers have reported a decrease in surgical resections and an increase in intracranial monitoring. Despite this increase in complexity, epilepsy surgery remains significantly underutilized. The goal of this study is to examine the utilization of and access to epilepsy surgery in the United States from 2006 to 2016. METHODS: We used administrative datasets from the National Inpatient Sample (NIS) and Center for Medicare and Medicaid Services (CMS) to report national estimates of epilepsy surgery and changes in surgery types. We also examined disparities and barriers in access to epilepsy surgery. RESULTS: Inpatient epilepsy admissions increased from 2.41 to 5.78 per 100,000 between 2006 and 2016, while surgical epilepsy admissions plateaued after 2011. Open resections comprised 75 % of all surgical cases from 2006 to 2011 then decreased each year to 50 % in 2016 with both temporal and extratemporal resections decreasing proportionally. Intracranial monitoring increased in the last two years of the study due to an increase in SEEG/depth electrode cases. The multivariate analysis showed that patients with Medicaid (OR 0.75, 95 % CI 0.67-0.83) and Medicare (OR 0.62, 95 % CI 0.54-0.70) were significantly less likely to undergo epilepsy surgery compared to those with private insurance. Black patients were less likely to undergo epilepsy surgery than White or Hispanic patients (OR 0.57, 95 % CI 0.49-0.67). No significant difference was found in epilepsy surgery rates after implementation of the Affordable Care Act (ACA) in 2014. CONCLUSION: This study identifies recent trends in epilepsy surgical approaches and suggests that improving access to care does not necessarily address disparities present in the treatment of epilepsy patients who need surgical care.


Asunto(s)
Epilepsia , Patient Protection and Affordable Care Act , Anciano , Epilepsia/epidemiología , Epilepsia/cirugía , Etnicidad , Disparidades en Atención de Salud , Humanos , Medicaid , Medicare , Estados Unidos
9.
Rev. Soc. Cardiol. Estado de Säo Paulo ; 31(supl. 2B): 188-188, abr-jun., 2021. ilus.
Artículo en Portugués | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1290501

RESUMEN

INTRODUÇÃO: As anomalias coronárias congênitas são raras na população geral, com uma prevalência de 0,2 a 2,3%. Nos pacientes adultos a variante anatômica mais frequente é a artéria circunflexa (CX) anômala, tendo como possíveis origens o óstio separado dentro do seio coronário direito ou ramo proximal da arteria coronária direita (CD), sendo este último bastante incomum. O diagnóstico na maioria dos casos é realizado como um achado incidental durante uma cinecoronariografia. RELATO DE CASO: Paciente masculino, 71 anos, portador de hipertensão arterial sistêmica, diabetes mellitus, dislipidemia, hipotireoidismo, doença pulmonar obstrutiva crónica e ex-tabagista, com história de Doença Arterial Coronária Crónica (DAC) com revascularização miocárdica cirúrgica há sete anos, encaminhado ao nosso serviço por queixa de dispneia classe funcional NYHA II. Negava angina. Eletrocardiograma apresentava alteração inespecífica da repolarização ventricular e o ecocardiograma transtorácico revelou função ventricular preservada. Realizou prova funcional com evidência de isquemia em parede inferior e inferolateral (carga isquêmica 10-14%). Desta forma, foi submetido a cateterismo cardíaco que evidenciou Artéria Coronária Direita ocluída em terço proximal, descendente anterior (DA) com lesão de 95% no terço proximal enchendo retrogradamente por ponte de artéria mamaria interna esquerda pérvia, ponte safena para primeiro ramo diagonal ocluída e pontes safena para descendente posterior e primeiro ramo marginal pérvios. Evidenciada CX originando-se do seio coronário direito, achado não relatado previamente a despeito dos antecedentes do paciente. O caso foi discutido em HEART TEAM e optado por manutenção de tratamento clínico otimizado. DISCUSSÃO: A investigaçãoda doença aterosclerótica coronaria leva, por vezes, à necessidade de cinecoronarografia, o que pode levar ao diagnóstico de anomalias congênitas, sendo a origem de CX a partir do seio de valsalva direito um achado raro. Nos pacientes adultos que apresentam essas variantes anatómicas, a isquemia miocárdica pode ocorrer devido à aterosclerose precoce e mais agressiva quando comparada a uma artéria coronária normal, sendo descrito na literatura uma maior incidencia de estenoses em artérias com origem anômala do seio coronario direito. CONCLUSÃO: Trata-se de caso pouco frequente de um paciente com DAC e origem anômalada CX. Na literatura varios autores já sugerem esta associação, porém o prognóstico desses pacientes ainda é incerto e tratamento permanece um Figura 1. A - ECG com critérios clássico para HVE e alterações da repolarização ventricular, RNM de coração desafio.


Asunto(s)
Humanos , Masculino , Anciano , Enfermedad de la Arteria Coronaria , Cardiopatías Congénitas
10.
Ann Thorac Surg ; 105(3): 893-900, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29394994

RESUMEN

BACKGROUND: Lung disease is the leading cause of morbidity and death in scleroderma patients, but scleroderma is often considered a contraindication to lung transplantation because of concerns for worse outcomes. We evaluated whether 5-year survival in scleroderma patients after lung transplantation differed from other patients with restrictive lung disease. METHODS: This was a single-center, retrospective cohort study of all patients undergoing bilateral lung transplantation for scleroderma-related pulmonary disease between January 2006 and December 2014. This cohort was compared with patients undergoing bilateral lung transplantation for nonscleroderma group D restrictive disease. Primary outcomes reported were 1-year and 5-year survival. Diagnoses were identified by United Network of Organ Sharing listing and were confirmed by clinical examination and prelisting workup. RESULTS: We compared 26 patients who underwent BLT for scleroderma and 155 patients who underwent BLT for group D restrictive disease. Overall, the nonscleroderma cohort was younger, with lower lung allocation score but no difference in functional status. Donor characteristics were not different between the cohorts. Survival at 1 year was not different (73.1% vs 80.0%, p = 0.323). Long-term survival at 5 years was also not significantly different (65.4% vs 66.5%, p = 0.608). Multivariate Cox proportional hazards analysis found no differences in survival between scleroderma and nonscleroderma group D restrictive disease (hazard ratio, 2.19; p = 0.122). CONCLUSIONS: Despite being at high risk for extrapulmonary complications, patients undergoing bilateral lung transplantation for scleroderma have similar 1-year and 5-year survival as those with restrictive lung disease. Transplantation is a reasonable treatment option for a carefully selected population of candidates.


Asunto(s)
Enfermedades Pulmonares/mortalidad , Enfermedades Pulmonares/cirugía , Trasplante de Pulmón , Esclerodermia Sistémica/mortalidad , Esclerodermia Sistémica/cirugía , Adulto , Anciano , Femenino , Humanos , Enfermedades Pulmonares/etiología , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Esclerodermia Sistémica/complicaciones , Tasa de Supervivencia , Resultado del Tratamiento
11.
Opt Express ; 26(24): 31554-31566, 2018 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-30650739

RESUMEN

We experimentally demonstrate a disruptive approach to control magnetooptical nonreciprocal effects. It has been known that the combination of a magneto-optically (MO) active substrate and extraordinary transmission (EOT) effects through deep-subwavelength nanoslits of a noble metal grating, leads to giant enhancements of the magnitude of the MO effects that would normally be obtained on just the bar substrate. This was demonstrated both in the transmission configuration, where the OET is directly observed, as well as in reflection configuration, where an increase of a transmitted power results in a decrease in reflected power. We show here that even more than just an enhancement, the MO effects can also undergo a sign reversal by achieving a hybridization of the different types of resonances at play in these EOT nanogratings. By tuning the geometrical profile of the grating's slits, one can engineer - for a fixed wavelength and fixed magnetization - the transverse MO Kerr effect (TMOKE) reflectivity of such a magnetoplasmonic system to be enhanced, extinguished or inversely enhanced. We have fabricated gold gratings with varying nanoslit widths on a Bi-substituted gadolinium iron garnet and experimentally confirmed such a behavior using a customized magneto-optic Mueller matrix ellipsometer. This demonstration allows new design paradigms for integrated nonreciprocal circuits and biochemical sensors with increased sensitivity and reduced footprint.

12.
Oper Neurosurg (Hagerstown) ; 13(1): 108-112, 2017 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-28931262

RESUMEN

BACKGROUND: The potential for simulation-based learning in neurosurgical training has led the Congress of Neurosurgical Surgeons to develop a series of simulation modules. The Northwestern Objective Microanastomosis Assessment Tool (NOMAT) was created as the corresponding assessment tool for the Congress of Neurosurgical Surgeons Microanastomosis Module. The face and construct validity of the NOMAT have been previously established. OBJECTIVE: To further validate the NOMAT by determining its interrater reliability (IRR) between raters of varying levels of microsurgical expertise. METHODS: The NOMAT was used to assess residents' performance in a microanastomosis simulation module in 2 settings: Northwestern University and the Society of Neurological Surgeons 2014 Boot Camp at the University of Indiana. At Northwestern University, participants were scored by 2 experienced microsurgeons. At the University of Indiana, participants were scored by 2 postdoctoral fellows and an experienced microsurgeon. The IRR of NOMAT was estimated by computing the intraclass correlation coefficient using SPSS v22.0 (IBM, Armonk, New York). RESULTS: A total of 75 residents were assessed. At Northwestern University, 21 residents each performed microanastomosis on 2 model vessels of different sizes, one 3 mm and one 1 mm. At the University of Indiana, 54 residents performed a single microanastomosis procedure on 3-mm vessels. The intraclass correlation coefficient of the total NOMAT scores was 0.88 at Northwestern University and 0.78 at the University of Indiana. CONCLUSION: This study indicates high IRR for the NOMAT. These results suggest that the use of raters with varying levels of expertise does not compromise the precision or validity of the scale. This allows for a wider adoption of the scale and, hence, a greater potential educational impact.


Asunto(s)
Anastomosis Quirúrgica/métodos , Competencia Clínica , Educación Médica Continua , Internado y Residencia , Modelos Anatómicos , Neurocirujanos/educación , Simulación por Computador , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados
13.
World Neurosurg ; 108: 988.e15-988.e20, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28830738

RESUMEN

BACKGROUND: Dural arteriovenous fistula (DAVF) is an abnormal vascular connection between arterial and venous channels within dura mater. Although DAVFs have been linked to other types of intracranial tumors, this is the first case reporting the association between DAVF and an epidermoid tumor. CASE DESCRIPTION: A middle-aged patient with chronic headache presented with Borden type II DAVF draining into the right transverse sigmoid junction and was also found to have an epidermoid tumor over the right mastoid. The patient underwent staged embolization of the fistula through both transvenous and transarterial routes. Continuous intraoperative venous pressure monitoring confirmed marked reduction in intracranial venous pressure, and the patient's symptoms completely resolved. However, the fistula still remained. The residual DAVF was then surgically disconnected, and the epidermoid tumor was resected in the same procedure. CONCLUSIONS: This case demonstrates a DAVF can be associated with an epidermoid tumor. Tumor can compromise the venous outflow, which can then lead to intracranial venous hypertension and development of the DAVF. Venous pressure monitoring offers an objective method to verify resolution of venous hypertension, which might correlate with resolution of clinical symptoms.


Asunto(s)
Malformaciones Vasculares del Sistema Nervioso Central/diagnóstico por imagen , Senos Craneales , Quiste Epidérmico/diagnóstico por imagen , Apófisis Mastoides/diagnóstico por imagen , Malformaciones Vasculares del Sistema Nervioso Central/complicaciones , Malformaciones Vasculares del Sistema Nervioso Central/terapia , Angiografía Cerebral , Imagen de Difusión por Resonancia Magnética , Embolización Terapéutica , Quiste Epidérmico/complicaciones , Quiste Epidérmico/cirugía , Humanos , Presión Intracraneal , Imagen por Resonancia Magnética , Apófisis Mastoides/cirugía , Persona de Mediana Edad , Monitoreo Intraoperatorio , Procedimientos Neuroquirúrgicos , Presión Venosa
14.
World Neurosurg ; 97: 27-38, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27693247

RESUMEN

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a more common than previously noted condition (1-2.5 per 50,000 persons) typically caused by cerebrospinal fluid (CSF) leakage. Initial treatment involves conservative therapies, but the mainstay of treatment for patients who fail conservative management is the epidural blood patch (EBP). Subdural hematoma (SDH) is a common complication occurring with SIH, but its management remains controversial. METHODS: In this report, we discuss a 62-year-old woman who presented with a 5-week history of orthostatic headaches associated with nausea, emesis, and neck pain. Despite initial imaging being negative, the patient later developed classic imaging evidence characteristic of SIH. Magnetic resonance imaging was unrevealing for the source of the CSF leak. Radionuclide cisternography showed possible CSF leak at the right-sided C7-T1 nerve root exit site. After failing a blind lumbar EBP, subsequent targeted EBP at C7-T1 improved the patient's symptoms. Two days later she developed a new headache with imaging evidence of worsening SDH with midline shift requiring burr hole drainage. This yielded sustained symptomatic relief and resolution of previously abnormal imaging findings at 2-month follow-up. RESULTS: A literature review revealed 174 cases of SIH complicated by SDH. This revealed conflicting opinions concerning the management of this condition. CONCLUSIONS: Although blind lumbar EBP is often successful, targeted EBP has a lower rate of patients requiring a second EBP or other further treatment. On the other hand, targeted EBP has a larger risk profile. Depending on the clinic situation, treatment of the SDH via surgical evacuation may be necessary.


Asunto(s)
Parche de Sangre Epidural/métodos , Manejo de la Enfermedad , Hematoma Subdural/etiología , Hematoma Subdural/terapia , Hipotensión Intracraneal/complicaciones , Femenino , Hematoma Subdural/diagnóstico por imagen , Humanos , Hipotensión Intracraneal/diagnóstico por imagen , Imagen por Resonancia Magnética , Persona de Mediana Edad
15.
Sci Rep ; 6: 32781, 2016 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-27608533

RESUMEN

Excitation of magnetization dynamics by pure spin currents has been recently recognized as an enabling mechanism for spintronics and magnonics, which allows implementation of spin-torque devices based on low-damping insulating magnetic materials. Here we report the first spatially-resolved study of the dynamic modes excited by pure spin current in nanometer-thick microscopic insulating Yttrium Iron Garnet disks. We show that these modes exhibit nonlinear self-broadening preventing the formation of the self-localized magnetic bullet, which plays a crucial role in the stabilization of the single-mode magnetization oscillations in all-metallic systems. This peculiarity associated with the efficient nonlinear mode coupling in low-damping materials can be among the main factors governing the interaction of pure spin currents with the dynamic magnetization in high-quality magnetic insulators.

16.
Paediatr Anaesth ; 26(8): 823-30, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27247166

RESUMEN

BACKGROUND: Percutaneous cannulation of the femoral artery in the pediatric age group can be technically challenging, especially when performed by residents in training. OBJECTIVE: We examined whether the use of real-time ultrasound guidance is superior to a palpation landmark technique for femoral artery catheterization in children undergoing heart surgery. METHODS: Patients were prospectively randomized into two groups. In the palpation group, the femoral artery was cannulated using the traditional landmark method of palpation of arterial pulse. In the ultrasound group, cannulation was guided by real-time scanning with an ultrasound probe. Ten minutes were set as time limit for the resident's trials during which the time taken for attempted cannulation (primary outcome), number of attempts, number of successful cannulations on first attempt, and success rate were compared between the two groups. Adverse events were monitored on postoperative days 1 and 3. RESULTS: A total of 106 patients were included in the study. The time taken for attempted femoral artery cannulation was shorter (301 ± 234 vs 420 ± 248 s; difference in mean: 119; 95% confidence interval (CI) of difference: 26-212; P = 0.012) and the number of attempts was lower [1 (1-10) vs 2 (1-5); difference in median: 1, 95% CI of difference: 0.28-1.72; P = 0.003] in the ultrasound group compared with the palpation group. The number of successful cannulations on first attempt was higher in the ultrasound group compared with palpation group [24/53 (45%) vs 13/53 (25%); odds ratio (OR): 2.54, 95% CI: 1.11-5.82; P = 0.025]. The number of patients who had successful cannulation was 31 of 55 (58%) in the palpation group and 40 of 53 (75%) in the ultrasound group (OR: 2.18, 95% CI: 0.95-5.01; P = 0.06). None of the patients had adverse events at days 1 and 3. CONCLUSIONS: Ultrasound-guided femoral arterial cannulation in children when performed by anesthesia residents is superior to the palpation technique based on the reduction of the time taken for attempted cannulation and the number of attempts, and improvement in first attempt success.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Cateterismo Periférico/métodos , Arteria Femoral , Internado y Residencia , Palpación/métodos , Ultrasonografía Intervencional/métodos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos
17.
Diabetes Obes Metab ; 18(11): 1110-1119, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27333970

RESUMEN

AIMS: To test whether adjusting insulin and glucagon in response to exercise within a dual-hormone artificial pancreas (AP) reduces exercise-related hypoglycaemia. MATERIALS AND METHODS: In random order, 21 adults with type 1 diabetes (T1D) underwent three 22-hour experimental sessions: AP with exercise dosing adjustment (APX); AP with no exercise dosing adjustment (APN); and sensor-augmented pump (SAP) therapy. After an overnight stay and 2 hours after breakfast, participants exercised for 45 minutes at 60% of their maximum heart rate, with no snack given before exercise. During APX, insulin was decreased and glucagon was increased at exercise onset, while during SAP therapy, subjects could adjust dosing before exercise. The two primary outcomes were percentage of time spent in hypoglycaemia (<3.9 mmol/L) and percentage of time spent in euglycaemia (3.9-10 mmol/L) from the start of exercise to the end of the study. RESULTS: The mean (95% confidence interval) times spent in hypoglycaemia (<3.9 mmol/L) after the start of exercise were 0.3% (-0.1, 0.7) for APX, 3.1% (0.8, 5.3) for APN, and 0.8% (0.1, 1.4) for SAP therapy. There was an absolute difference of 2.8% less time spent in hypoglycaemia for APX versus APN (p = .001) and 0.5% less time spent in hypoglycaemia for APX versus SAP therapy (p = .16). Mean time spent in euglycaemia was similar across the different sessions. CONCLUSIONS: Adjusting insulin and glucagon delivery at exercise onset within a dual-hormone AP significantly reduces hypoglycaemia compared with no adjustment and performs similarly to SAP therapy when insulin is adjusted before exercise.


Asunto(s)
Técnicas Biosensibles/instrumentación , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Ejercicio Físico/fisiología , Glucagón/administración & dosificación , Hipoglucemiantes/administración & dosificación , Sistemas de Infusión de Insulina , Insulina/administración & dosificación , Páncreas Artificial , Adolescente , Adulto , Técnicas Biosensibles/métodos , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Estudios Cruzados , Diabetes Mellitus Tipo 1/sangre , Relación Dosis-Respuesta a Droga , Femenino , Glucagón/efectos adversos , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemia/prevención & control , Hipoglucemiantes/efectos adversos , Insulina/efectos adversos , Masculino , Persona de Mediana Edad , Páncreas Artificial/efectos adversos , Adulto Joven
18.
Nat Commun ; 7: 10377, 2016 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-26815737

RESUMEN

In recent years, spin-orbit effects have been widely used to produce and detect spin currents in spintronic devices. The peculiar symmetry of the spin Hall effect allows creation of a spin accumulation at the interface between a metal with strong spin-orbit interaction and a magnetic insulator, which can lead to a net pure spin current flowing from the metal into the insulator. This spin current applies a torque on the magnetization, which can eventually be driven into steady motion. Tailoring this experiment on extended films has proven to be elusive, probably due to mode competition. This requires the reduction of both the thickness and lateral size to reach full damping compensation. Here we show clear evidence of coherent spin-orbit torque-induced auto-oscillation in micron-sized yttrium iron garnet discs of thickness 20 nm. Our results emphasize the key role of quasi-degenerate spin-wave modes, which increase the threshold current.

19.
Clin Neurol Neurosurg ; 142: 65-71, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26811865

RESUMEN

BACKGROUND AND SIGNIFICANCE: The vessels of choice for cerebrovascular high-flow direct bypass procedures are the radial artery and the saphenous vein. Radial artery grafts have become favored over saphenous vein grafts because of higher patency rates and better size matching to appropriate recipient vessels. Radial grafts are prone to spasm however, and this may be seen in 4-10% of cases and can be associated with ischemic sequelae. The standard technique for radial artery harvest calls for complete separation of the artery from its adventitial attachments and associated venous network. There is reason to believe that this could contribute to spasm risk and possibly even thrombosis. Radial graft outcomes appear to be improved when the vena comitantes is preserved in cardiac and peripheral applications. We report the novel use of a harvested radial artery graft with preservation of its venae comitantes for extracranial to intracranial bypass. CLINICAL PRESENTATION: The patient is a 59-year-old male who had a blunt head trauma with associated loss of consciousness and who was led to the incidental discovery of a large fusiform middle cerebral artery (MCA) aneurysm. CONCLUSION: Preservation of the vena comitantes when harvesting a radial arterial graft for bypass, along with dual (arterial and venous) anastomoses, and concomitant use of intra-operative vaso-dilatory maneuvers to prevent spasm, may improve overall graft patency and patient outcome.


Asunto(s)
Venas Cerebrales/cirugía , Aneurisma Intracraneal/cirugía , Arteria Radial/trasplante , Revascularización Cerebral/métodos , Humanos , Riesgo , Trasplante Autólogo , Resultado del Tratamiento
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