RESUMO
BACKGROUND: Current radiological assessments of 18fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging data in diffuse large B-cell lymphoma (DLBCL) can be time consuming, do not yield real-time information regarding disease burden and organ involvement, and hinder the use of FDG-PET to potentially limit the reliance on invasive procedures (e.g. bone marrow biopsy) for risk assessment. METHODS: Our aim is to enable real-time assessment of imaging-based risk factors at a large scale and we propose a fully automatic artificial intelligence (AI)-based tool to rapidly extract FDG-PET imaging metrics in DLBCL. On availability of a scan, in combination with clinical data, our approach generates clinically informative risk scores with minimal resource requirements. Overall, 1268 patients with previously untreated DLBCL from the phase III GOYA trial (NCT01287741) were included in the analysis (training: n = 846; hold-out: n = 422). RESULTS: Our AI-based model comprising imaging and clinical variables yielded a tangible prognostic improvement compared to clinical models without imaging metrics. We observed a risk increase for progression-free survival (PFS) with hazard ratios [HR] of 1.87 (95% CI: 1.31-2.67) vs 1.38 (95% CI: 0.98-1.96) (C-index: 0.59 vs 0.55), and a risk increase for overall survival (OS) (HR: 2.16 (95% CI: 1.37-3.40) vs 1.40 (95% CI: 0.90-2.17); C-index: 0.59 vs 0.55). The combined model defined a high-risk population with 35% and 42% increased odds of a 4-year PFS and OS event, respectively, versus the International Prognostic Index components alone. The method also identified a subpopulation with a 2-year Central Nervous System (CNS)-relapse probability of 17.1%. CONCLUSION: Our tool enables an enhanced risk stratification compared with IPI, and the results indicate that imaging can be used to improve the prediction of central nervous system relapse in DLBCL. These findings support integration of clinically informative AI-generated imaging metrics into clinical workflows to improve identification of high-risk DLBCL patients. TRIAL REGISTRATION: Registered clinicaltrials.gov number: NCT01287741.
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Fluordesoxiglucose F18 , Linfoma Difuso de Grandes Células B , Inteligência Artificial , Automação , Ensaios Clínicos Fase III como Assunto , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/patologia , Recidiva Local de Neoplasia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Prognóstico , Medição de Risco , Carga TumoralRESUMO
The VISA-A questionnaire has proven to be a valid and reliable tool for assessing severity of Achilles tendinopathy (AT). The aim was to translate and cross-culturally adapt the VISA-A questionnaire for a Danish-speaking AT population, and subsequently perform validity and reliability tests. Translation and following cross-cultural adaptation was performed as translation, synthesis, reverse translation, expert review, and pretesting. The final Danish version (VISA-A-DK) was tested for reliability on healthy controls (n = 75) and patients (n = 36). Tests for internal consistency, validity, and structure were performed on 71 patients. VISA-A-DK showed good reliability for patients (r = 0.80 ICC = 0.79) and healthy individuals (r = 0.98 ICC = 0.97). Internal consistency was 0.73 (Cronbach's alpha). The mean VISA-A-DK score in AT patients was 51 [47-55]. This was significantly lower than healthy controls with a score of 93 (90-95). Criterion validity was considered good when comparing the scores of the Danish version with the original version in both healthy individuals and patients. VISA-A-DK is a valid and reliable instrument and has shown compatible to the original version in assessment of AT patients. VISA-A-DK is a useful tool in the assessment of AT, both in research and in a clinical setting.
Assuntos
Tendão do Calcâneo/fisiopatologia , Tendinopatia/fisiopatologia , Adulto , Estudos de Casos e Controles , Competência Cultural , Transtornos Traumáticos Cumulativos/diagnóstico , Transtornos Traumáticos Cumulativos/fisiopatologia , Dinamarca , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Inquéritos e Questionários , Tendinopatia/diagnóstico , TraduçõesRESUMO
Copepods of the genus Calanus are key zooplankton species in temperate to arctic marine ecosystems. Despite their ecological importance, species identification remains challenging. Furthermore, the recent report of hybrids among Calanus species highlights the need for diagnostic nuclear markers to efficiently identify parental species and hybrids. Using next-generation sequencing analysis of both the genome and transcriptome from two sibling species, Calanus finmarchicus and Calanus glacialis, we developed a panel of 12 nuclear insertion/deletion markers. All the markers showed species-specific amplicon length. Furthermore, most of the markers were successfully amplified in other Calanus species, allowing the molecular identification of Calanus helgolandicus, Calanus hyperboreus and Calanus marshallae.
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Copépodes/classificação , Copépodes/genética , Marcadores Genéticos , Mutagênese Insercional , Deleção de Sequência , Animais , Genoma , Dados de Sequência Molecular , Análise de Sequência de DNA , TranscriptomaRESUMO
Total mercury (THg), methylmercury (MeHg) and stable isotopes of nitrogen (delta(15)N) and carbon (delta(13)C) were measured in three invertebrate, five fish, three seabird and three marine mammal species of central West Greenland to investigate trophic transfer of mercury in this Arctic marine food web. The food web magnification factor (FWMF) estimated as the slope of the regression between the natural logarithm of THg or MeHg concentrations (mg kg(-1) dw) and tissue delta(15)N ( per thousand) was estimated to 0.183 (SE = 0.052) for THg and 0.339 (SE = 0.075) for MeHg. The FWMFs were not only comparable with those reported for other Arctic marine food webs but also with quite different food webs such as freshwater lakes in the sub-Arctic, East Africa and Papua New Guinea. This suggests similar mechanisms of mercury assimilation and isotopic (delta(15)N) discrimination among a broad range of aquatic taxa and underlines the possibility of broad ecosystem comparisons using the combined contaminant and stable isotope approach.
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Ecossistema , Monitoramento Ambiental/métodos , Cadeia Alimentar , Mercúrio/metabolismo , Poluentes Químicos da Água/análise , Animais , Aves/metabolismo , Isótopos de Carbono , Peixes/metabolismo , Groenlândia , Invertebrados/metabolismo , Isótopos de Nitrogênio , Água do Mar , Poluentes Químicos da Água/metabolismoRESUMO
OBJECTIVES: Saphenous vein injury is believed to predispose to vein graft stenoses. The aims of this study were to assess the endothelial injury associated with infrainguinal vein bypass surgery by serial measurements of serum thrombomodulin concentration as well as by platelet scintigraphy, and to relate these findings with the postoperative development of stenoses. METHODS: In 35 patients undergoing vein bypass surgery serum thrombomodulin concentration was measured pre- and postoperatively. Autologous 111-indium labelled platelets were administered into the common femoral artery immediately after restoration of flow in the graft and scintigraphic images were obtained 4 and/or 24 h later. RESULTS: Serum thrombomodulin increased markedly from median 17 ng/ml preoperatively to 32 ng/ml 1 day after surgery (p =0.00002). Platelet scintigraphy revealed a total of 62 focal activity accumulations, the majority being located in the anastomotic regions. Among the 30 patients with grafts remaining patent at 30 days stenoses occurred in nine (16%) of 55 regions with scintigraphic platelet accumulations as compared to only four (4%) of 94 regions without platelet accumulations (p =0.03). CONCLUSIONS: The very high predictive value of a negative platelet scintigraphy (96%) strongly suggests that localised perioperative endothelial injury is an important pathogenetic factor in the development of vein graft stenoses.
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Plaquetas/diagnóstico por imagem , Endotélio Vascular/fisiopatologia , Oclusão de Enxerto Vascular/diagnóstico , Trombomodulina/sangue , Veias/transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Feminino , Seguimentos , Oclusão de Enxerto Vascular/epidemiologia , Oclusão de Enxerto Vascular/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Cintilografia , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Veias/fisiopatologiaRESUMO
A simple and strictly all-fiber 1300-nm cw laser is presented. It is tunable over 16 nm with 0.5-nm linewidth and several milliwatts of output power in the whole tuning range from 1292 to 1308 nm. The setup uses a fiber Bragg grating as a combined tuning element and narrow-band output mirror. The simplicity and stability of this system are due to the following two characteristics: First, polarization control is not necessary anywhere in the system, and second, a wavelength-selective system and a narrow-band mirror are combined into one novel fiber-optic element.
RESUMO
The aim of the study was to examine the recommendations for prophylactic contralateral orchiopexy in patients presenting with unilateral testicular torsion in Denmark. A questionnaire was mailed to the 61 surgical departments treating acute urological patients. Prophylactic contralateral orchiopexy was performed in 60 of the 61 departments. Twenty-eight departments routinely performed a combined ipsilateral and contralateral operation. In 20 departments the contralateral procedure was performed immediately in the case of a vital ipsilateral testis, but delayed a median of five (3-12) weeks in the case of a necrotic testis. In seven departments the contralateral orchiopexy was routinely performed a median of 10 (2-12) weeks after the ipsilateral operation, and in the remaining five departments the time of the contralateral procedure was determined by the surgeon. In conclusion prophylactic contralateral orchiopexy was widely used in patients with unilateral testicular torsion, but the timing of the procedure varied.
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Orquiectomia/métodos , Torção do Cordão Espermático/prevenção & controle , Dinamarca , Humanos , Masculino , Guias de Prática Clínica como Assunto , Padrões de Prática Médica , Inquéritos e QuestionáriosRESUMO
Enothelial injury is assumed to be of pathogenetic significance in the development of graft stenoses, which remain a major cause of failure of peripheral bypasses. The aim of this study was to assess endothelial injury related to infrainguinal bypass surgery by indium-111 platelet scintigraphy. In 28 patients undergoing in situ vein (n = 24), composite vein-polytetrafluoroethylene (PTFE) (n = 1) or PTFE (n = 3) bypass surgery, assumed vascular injuries were recorded intraoperatively. Autologous indium-111-labelled platelets were injected into the inflow artery immediately after restoration of flow in the graft. Platelet deposition was assessed by gamma-camera images of thigh and crus obtained 4 and/or 24 h after surgery. Areas of focally increased activity were recorded and graded as moderate or intense. In the 24 vein bypasses, a median of two (range 0-5) areas of focally increased radioactivity were seen at the proximal anastomosis (n = 21), in the body of the graft (n = 20) or at the distal anastomosis (n = 9). The activity was moderate in 27 cases and intense in 23 cases. Scintigraphic evidence of focal platelet aggregation in vein grafts was not correlated with preoperative antiplatelet therapy or vein graft diameter. Only 2 of the 20 intragraft platelet depositions occurred in areas where intra-operative vascular injury was suspected. In the composite graft and the PTFE grafts, diffuse activity was observed throughout the entire bypass. In conclusion, focal activity accumulations, suggesting localized endothelial injury, were observed in the majority of in situ vein bypasses, in particular at the sites of the anastomoses. Prosthetic bypasses were characterized by diffuse platelet aggregation.
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Plaquetas/fisiologia , Ponte de Artéria Coronária , Idoso , Idoso de 80 Anos ou mais , Angiografia , Feminino , Humanos , Radioisótopos de Índio , Masculino , Pessoa de Meia-Idade , Agregação Plaquetária , Politetrafluoretileno , Período Pós-Operatório , Fatores de Risco , Veia Safena/diagnóstico por imagem , UltrassonografiaRESUMO
OBJECTIVES: To assess the association between antibodies to cardiolipin and infrainguinal vein graft patency. MATERIALS AND METHODS: Plasma levels of antibodies to cardiolipin, haemostatic factors, lipids and the smoking marker carboxyhaemoglobin were determined preoperatively and 6 weeks postoperatively in 80 patients undergoing infrainguinal vein bypass surgery. Bypass patency was assessed by ankle blood pressure measurements and ultrasound duplex scanning at 1 week, 6 weeks, 3, 6, 9 and 12 months. A localised increase in the graft peak systolic velocity by a factor of 2.5 or more was considered to indicate a significant stenosis. RESULTS: Antibodies to cardiolipin were identified in seven (9%) patients preoperatively. In four of these seven patients the bypasses thrombosed within 3 months after surgery and another two developed stenoses. At 6 months the primary bypass patency, i.e. patency without stenosis, was 14% (95% confidence interval (CI) 0-33%) in patients with antibodies to cardiolipin, as opposed to 57% (95% CI 45-69%) in patients without these antibodies (log rank test: p = 0.03). Diabetes mellitus was also associated with a reduced 6 months primary bypass patency (38% (95% CI 16-60%) vs. 58% (95% CI 45-71%), p = 0.006). A Cox regression analysis showed that both the presence of antibodies to cardiolipin and diabetes independently contributed towards predicting the overall risk of bypass failure. CONCLUSION: Antibodies to cardiolipin were identified in 9% of patients undergoing infrainguinal vein bypass surgery and appeared to be associated with increased risk of bypass failure.
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Anticorpos Anticardiolipina/sangue , Derivação Arteriovenosa Cirúrgica , Oclusão de Enxerto Vascular/epidemiologia , Doenças Vasculares Periféricas/cirurgia , Idoso , Prótese Vascular , Diabetes Mellitus/epidemiologia , Feminino , Seguimentos , Oclusão de Enxerto Vascular/imunologia , Humanos , Perna (Membro)/irrigação sanguínea , Lipoproteína(a)/sangue , Lipoproteínas LDL/imunologia , Masculino , Doenças Vasculares Periféricas/imunologia , Modelos de Riscos Proporcionais , Fatores de Risco , Veia Safena/transplante , Fatores de Tempo , Falha de Tratamento , Grau de Desobstrução VascularRESUMO
OBJECTIVES: To assess the risk of graft stenoses following early thrombectomy of peripheral vein bypasses. DESIGN: Prospective study of 371 vein bypasses performed at the Vascular Service, Rigshospitalet, Copenhagen from January 1991 through December 1992. MATERIALS AND METHODS: Thirty-six vein bypasses reopened by thrombectomy within 30 days postoperatively (group I) and 335 bypasses not subjected to early thrombectomy (group II) were studied by ultrasound duplex scanning 3, 6, 9, 12, 18, 24, 36 and 48 months postoperatively. A localised increase in the peak systolic velocity of 250% or more was considered an indicator for significant stenosis. RESULTS: In the perioperative period nine (2%) patients died, 30 (8%) bypasses occluded and 14 (4%) patients were lost to follow-up. Among the 318 patients remaining at risk at 1 month graft stenoses were identified in 39% (9/23) in group I compared to 17% (51/295) in group II, p = 0.03. Late bypass revisions were required in 35% (8/23) in group I as opposed to 9% (28/295) in group II, p = 0.004. Despite this high number of revisional procedures the 12-months secondary bypass patency was lower in recanalised grafts (38% vs. 82%, p < 0.00001). CONCLUSION: Early vein bypass thrombectomy is associated with a two-fold increased risk of graft related stenoses and a reduced secondary bypass patency.
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Oclusão de Enxerto Vascular/etiologia , Perna (Membro)/irrigação sanguínea , Trombectomia/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Oclusão de Enxerto Vascular/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Veia Safena/transplante , Fatores de Tempo , Ultrassonografia Doppler Dupla , Grau de Desobstrução VascularRESUMO
In 36 persons without nasal complaints nasal cavities were investigated using acoustic rhinometry (Rhin 2000), to study the effect of a nasal dilator (ND) named "Airplus". The minimal cross sectional area (MCA) of both the right and left side was assessed before and after application of the ND, and the total MCA was calculated as the sum of the right and left side. In 8 persons the MCA was measured before and after 2 applications of the ND. In 8 persons the MCA was measured before, immediately after and 2 hours after application of the ND. In trial one the median total MCA was 1.37 cm2 before and 1.96 cm2 after application of the ND. This corresponds to an increase of 43%, p < 0.000-01. In trial two the median total MCA was increased from 1.37 cm2 respectively 1.35 cm2 to 1.98 cm2 respectively 2.01 cm3, an increase of 45% respectively 49%, p < 0.008 in both. In trial three the median total MCA was 1.21 cm2 before and 1.95 cm2 immediately after application and 1.93 cm2 after 2 hours. The increase was 61 and 59%, p < 0.008 in both. The results show that the "Airplus" nasal dilator improves significantly the MCA, it was possible to reproduce the effect and it was stable in the recorded period.
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Cavidade Nasal/anatomia & histologia , Obstrução Nasal/terapia , Acústica , Dilatação/instrumentação , Desenho de Equipamento , Feminino , Humanos , MasculinoRESUMO
OBJECTIVE: To relate the histological composition of carotid artery plaques with morphology as evaluated by B-mode ultrasound. DESIGN: Prospective study. MATERIAL AND METHODS: Seventy-eight symptomatic patients underwent carotid endarterectomy after preoperative ultrasound Duplex scanning evaluating plaque morphology. Morphometric analysis of the removed specimen was performed in order to quantify content of lipid, haemorrhage, calcification and fibrous tissue. RESULTS: Echolucent plaques contained more lipid (p = 0.01) and less calcification (p = 0.01) and fibrous tissue (p = 0.03) than echo-rich plaques. Intraplaque haemorrhage was directly related to lipid content (p = 0.004) and inversely related to amount of fibrous tissue in the plaque (p = 0.02). CONCLUSION: The intensity of the reflected B-mode ultrasound signal appears related to the histological composition of the plaque. The association between intraplaque haemorrhage and a high lipid content may support the theory of the lipid-rich plaque being more prone to rupture.
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Arteriosclerose/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Hemorragia/diagnóstico por imagem , Lipídeos/análise , Arteriosclerose/patologia , Arteriosclerose/cirurgia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/patologia , Estenose das Carótidas/patologia , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas , Feminino , Hemorragia/patologia , Humanos , Lipoproteínas/sangue , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Risco , UltrassonografiaRESUMO
OBJECTIVES: To analyse the histopathological features of in situ vein bypass stenoses. MATERIALS AND METHODS: Nineteen specimens of primary (n = 16) or recurrent (n = 3) vein graft stenoses obtained from 17 patients during surgical revision were prepared for light microscopy and immunohistochemical investigation. The median time interval from bypass surgery to stenosis excision was 5 months (range 2-52 months). Twenty-seven saphenous vein segments obtained from patients undergoing primary bypass surgery served as controls. RESULTS: Graft stenoses were characterised by moderate to severe intimal hyperplasia composed of actin positive but desmin negative cells, interspersed with areas of fibrosis. A single layer of factor VIII positive endothelial cells were identified on the luminal surface. The media, separated from the intima by a poorly defined elastic lamina, usually appeared normal or mildly hyperplastic and consisted of smooth muscle cells, which stained positive for actin as well as for desmin. The adventitia was composed of loose connective tissue in which lymphocytes, plasma cells and giant cells were occasionally seen. Atheromatous material was absent from intragraft lesions, but was observed in one specimen, which was harvested from a proximal anastomotic lesion. The majority of pre-bypass vein segments showed evidence of intimal thickening whereas medial hyperplasia was less common. CONCLUSIONS: In situ vein bypass stenoses mainly consisted of intimal hyperplasia and varying degrees of fibrosis. Similar but less pronounced morphological changes were found in pre-bypass vein segments. The nature of the actin positive but desmin and factor VIII negative intima cells is uncertain, and further studies are needed to characterise this cell type.
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Oclusão de Enxerto Vascular/patologia , Veia Safena/transplante , Idoso , Estudos de Casos e Controles , Constrição Patológica/patologia , Feminino , Humanos , Hiperplasia , Técnicas Imunoenzimáticas , Masculino , Reoperação , Veia Safena/patologia , Fatores de Tempo , Túnica Íntima/patologiaRESUMO
BACKGROUND AND PURPOSE: Echolucent carotid atherosclerotic plaques are associated with an increased risk of neurological symptoms. Elevated plasma triglycerides is a risk factor for cerebral and coronary infarction. This study examined these individual pathogenetic risk factors to determine whether they were related. METHODS: We included 85 symptomatic patients with at least 40% carotid artery stenosis. Plaque morphology of the relevant artery was evaluated by high-resolution B-mode ultrasonography as echolucent, echo-rich, or intermediate. Fasting and postprandial lipids and lipoproteins were measured before and at hourly intervals for 4 hours after a fatty meal (1 g cream fat per kilogram body weight). RESULTS: When we compared patients with echolucent plaques to patients with echo-rich or intermediate plaques, the former had higher fasting and postprandial plasma triglycerides (P < or = .006), higher chylomicron remnants/VLDL cholesterol (P = .02) and triglycerides (P < or = .004), a larger area under the plasma triglyceride curve 0 to 4 hours after a fatty meal, with (AUCTG-TG oh) or without (AUCTG) subtraction of fasting levels (P = .007 and P = .003), a larger body mass index (P = .03), and were younger (P = .01). Multiple logistic regression analysis found that when age and body mass index were taken into account, fasting plasma and VLDL triglycerides, postprandial chylomicron remnants/VLDL triglycerides, AUCTG-TG oh and AUCTG with odds ratios of 4.1, 3.8, 3.0, 2.7, and 4.3, respectively, were independent predictors of an echolucent plaque. CONCLUSIONS: Echolucent carotid artery plaques are associated with elevated levels of triglyceride-rich lipoproteins in the fasting or postprandial state.
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Arteriosclerose/diagnóstico por imagem , Artérias Carótidas/diagnóstico por imagem , Estenose das Carótidas/diagnóstico por imagem , Quilomícrons/sangue , Lipoproteínas VLDL/sangue , Triglicerídeos/sangue , Adulto , Idoso , Arteriosclerose/sangue , Arteriosclerose/complicações , Índice de Massa Corporal , Doenças Cardiovasculares/complicações , Estenose das Carótidas/sangue , Estenose das Carótidas/complicações , Diabetes Mellitus Tipo 1/complicações , Gorduras na Dieta/administração & dosagem , Gorduras na Dieta/farmacologia , Ingestão de Alimentos , Jejum , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valor Preditivo dos Testes , Método Simples-Cego , UltrassonografiaRESUMO
PURPOSE: The purpose of this study was to assess the impact of arteriovenous fistulas combined with varying degrees of stenosis on distal bypass hemodynamics and Doppler spectral parameters. METHODS: In an in vitro flow model bypass stenoses causing 30%, 55%, and 70% diameter reduction were induced 10 cm upstream of a fistula with low outflow resistance. Flow and intraluminal pressure were measured proximal to the stenosis and downstream of the fistula. The waveform parameters peak systolic velocity, end-diastolic velocity, pulsatility index, and pulse rise time were determined from midstream Doppler spectra obtained 10 cm downstream of the fistula. All measurements were carried out with open and clamped fistula. RESULTS: At 30% diameter reducing stenosis opening of the fistula induced a 12% systolic pressure drop across the stenosis but had no adverse effect on the Doppler waveform parameters. At 55% stenosis the pressure drop increased from 16% to 31% after fistula opening. This increased pressure drop was associated with a further reduction in peak systolic velocity, a decrease in pulsatility index, and an enhanced pulse rise time prolongation. Fistula opening at 70% stenosis increased the systolic pressure drop from 31% to 48% and had significant impact on all waveform parameters. CONCLUSIONS: Distal arteriovenous fistulas enhance pressure loss across stenoses and affect downstream velocity waveform configuration. The presence of a combined fistula and a stenosis mimics the distal hemodynamic conditions of a more severe stenosis. Assessment of the hemodynamic impact of fistulas must be undertaken in the evaluation of in situ vein bypass stenoses.
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Fístula Arteriovenosa/fisiopatologia , Derivação Arteriovenosa Cirúrgica , Oclusão de Enxerto Vascular/fisiopatologia , Velocidade do Fluxo Sanguíneo , Hemodinâmica , Humanos , Perna (Membro)/irrigação sanguínea , Modelos Cardiovasculares , Veia Safena/transplante , Ultrassonografia DopplerRESUMO
OBJECTIVES: To describe the natural history of stenoses in infrainguinal vein bypasses and to identify factors predicting outcome. METHODS: Forty-two patients with non-revised vein bypass stenoses were followed prospectively by ultrasound Duplex scanning and ankle blood pressure measurements. RESULTS: During a median follow-up of 8 (range 0-22) months 18 (43%) (95% confidence limits 28-59%) bypasses thrombosed and 6 (14%) (95% confidence limits 5-29%) patients were amputated. Bypass patency was lower in 12 patients with stenoses associated with reduction in ankle brachial index (ABI) exceeding 0.15 than in 30 patients with no or only marginal reduction in ABI (12 month patency 33% vs. 68%, p = 0.005). Among the 30 patients without distal pressure reduction, stenoses identified within 3 months from surgery were associated with an increased risk of thrombosis as compared to stenoses identified at a later stage (12 month patency 51% vs. 92%, p = 0.03). CONCLUSION: Time interval from surgery to stenosis detection seems to be an independent parameter influencing outcome in patients with vein bypass stenoses.
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Arteriopatias Oclusivas/cirurgia , Oclusão de Enxerto Vascular/etiologia , Perna (Membro)/irrigação sanguínea , Trombose/etiologia , Veias/transplante , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Arteriopatias Oclusivas/diagnóstico por imagem , Pressão Sanguínea , Feminino , Seguimentos , Previsões , Oclusão de Enxerto Vascular/diagnóstico por imagem , Humanos , Canal Inguinal , Perna (Membro)/cirurgia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Estudos Prospectivos , Fatores de Risco , Trombose/diagnóstico por imagem , Resultado do Tratamento , Ultrassonografia Doppler Dupla , Veias/diagnóstico por imagemRESUMO
BACKGROUND: Recent studies have found satisfactory conditions for intubation of the trachea without using muscle relaxants using an intravenous technique combining propofol and alfentanil. In this study we evaluate intubating conditions with this method and either lignocaine applied topically in the larynx and trachea or placebo. METHODS: Sixty adult patients of ASA class I were premedicated with diazepam 15-20 mg and randomly allocated to one of two groups. For induction of anaesthesia both groups were given propofol 2.5 mg/kg and alfentanil 30 micrograms/kg. One group received 4 ml of lignocaine 40 mg/ml (< or = 3 mg/kg) topically into the larynx and trachea (group L), the other group an equal amount of isotonic saline (group S) in a double-blind design. Intubation conditions were assessed as excellent, good, moderately good, poor or impossible, scored on the basis of jaw relaxation, ease of insertion of the tube and coughing on intubation. RESULTS: The total score for group L was significantly better than the score for group S (P < 0.0001) with significant differences with respect to ease of intubation and coughing after intubation. CONCLUSIONS: Induction of anaesthesia with propofol 2.5 mg/kg and alfentanil 30 micrograms/kg combined with 4 ml of lignocainespray 40 mg/ml into the larynx and trachea offered consistent and satisfactory intubation conditions. We thus recommend this method for tracheal intubation, where the use of muscle relaxants is not indicated.
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Alfentanil , Anestesia Intravenosa , Anestésicos Locais/administração & dosagem , Intubação Intratraqueal , Lidocaína/administração & dosagem , Propofol , Administração Tópica , Adolescente , Adulto , Anestésicos Combinados , Anestésicos Intravenosos , Pressão Sanguínea , Método Duplo-Cego , Feminino , Frequência Cardíaca , Humanos , Laringe , Masculino , Tonsilectomia , TraqueiaRESUMO
A series of 124 patients had their greater saphenous vein assessed with duplex ultrasound scanning prior to planned infrainguinal bypass procedures. 33 (27%) bypass procedures thrombosed within the first year. A naturally occurring optimal vein diameter was discovered: 5.0-6.5 mm at mid-thigh level and 1.0-1.5 mm less at mid-calf level. It was significantly correlated with higher one year patency: thrombosis occured in 8% of the cases in veins with this optimal diameter combination and in 31% of the cases in all other combinations (P < 0.001).
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OBJECTIVES: To develop a simple protocol for ultrasound Duplex surveillance of infrainguinal vein bypasses. DESIGN: The value of three Doppler waveform parameters, obtained from a single point of the bypass, for identification of stenoses was studied in 91 in situ vein bypasses. Midgraft peak systolic velocity (PSV), pulsatility index (PI) and ratio of hyperaemic and resting time-average mean velocities (TAMV), (TAMV ratio = TAMVhyperaemia/TAMVrest) were correlated with the presence and severity of stenoses as assessed by conventional Duplex scanning and ankle-brachial index (ABI) measurements. The optimal value of the waveform parameters for discrimination between bypasses with and without evidence of stenoses was determined by receiver operating characteristics (ROC) analysis. MAIN RESULTS: Complete Duplex scanning of the entire graft revealed an increase in the peak systolic velocity by a factor 2.5 indicative of significant stenoses in 24 (26%) patients. A PSV below 55 cm/s was a poor indicator of stenoses (sensitivity 46%, specificity 76%) and PI < or = 3.8 only allowed suboptimal discrimination between normal and stenotic bypasses (sensitivity 63%, specificity 75%). The hyperaemic response assessed by TAMV ratio proved the best parameter for identification of graft stenoses. A TAMV ratio of 2.0 or less correctly identified 21 of the 24 lesions (sensitivity 88%, specificity 75%) and none of the three bypasses with evidence of stenoses and TAMV ratios exceeding 2.0 failed during follow-up. CONCLUSIONS: Single point waveform analysis of vein bypass velocity profile at rest and during reactive hyperaemia is a simple screening method providing diagnostic and prognostic information which may be of value in the postoperative surveillance of infrainguinal vein bypasses.
Assuntos
Oclusão de Enxerto Vascular/diagnóstico por imagem , Hiperemia/diagnóstico por imagem , Perna (Membro)/irrigação sanguínea , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/fisiopatologia , Feminino , Seguimentos , Oclusão de Enxerto Vascular/fisiopatologia , Virilha , Humanos , Hiperemia/fisiopatologia , Perna (Membro)/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Artéria Poplítea/cirurgia , Curva ROC , Veia Safena/transplante , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Ultrassonografia Doppler Dupla/instrumentação , Ultrassonografia Doppler Dupla/métodos , Ultrassonografia Doppler Dupla/estatística & dados numéricosRESUMO
Conventional treatment of iatrogenic pseudoaneurysms of the femoral artery after puncture during arteriography with or without additional balloon-angioplasty consists of surgical exposure and suture of the defect. The present paper describes colour-Doppler guided compression treatment of 10 femoral pseudoaneurysms. The aneurysm and its connection to the femoral artery is identified by ultrasound-colour-Doppler technique and using the transducer, pressure is applied on the aneurysm such that in- and outflow is stopped without disrupting the blood flow in the underlying femoral artery. In nine cases, where the pseudoaneurysms were less than two weeks old, treatment was successful in all cases. In the remaining patients, the pseudoaneurysm had developed shortly after arteriography and remained constant for one year. In this case, compression did not result in thrombosis. It is concluded that iatrogenic puncture-derived >>young<< pseudoaneurysms of the femoral artery should be treated by colour-Doppler compression except in cases of a rapidly developed large haematoma and circulatory instability. The latter cases should be operated immediately.