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1.
Toxicol Lett ; 319: 95-101, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678400

RESUMO

Physiologically based kinetic (PBK) models for farm animals are of growing interest in food and feed safety with key applications for regulated compounds including quantification of tissue concentrations, kinetic parameters and the setting of safe exposure levels on an internal dose basis. The development and application of these models requires data for physiological, anatomical and chemical specific parameters. Here, we present the results of a structured data collection of anatomical and physiological parameters in three key farm animal species (swine, cattle and sheep). We performed an extensive literature search and meta-analyses to quantify intra-species variability and associated uncertainty of the parameters. Parameters were collected for organ weights and blood flows in all available breeds from 110 scientific publications, of which 29, 48 and 33 for cattle, sheep, and swine, respectively. Organ weights were available in literature for all three species. Blood flow parameter values were available for all organs in sheep but were scarcer in swine and cattle. Furthermore, the parameter values showed a large intra-species variation. Overall, the parameter values and associated variability provide reference values which can be used as input for generic PBK models in these species.


Assuntos
Animais Domésticos/metabolismo , Bovinos/metabolismo , Farmacocinética , Carneiro Doméstico/metabolismo , Suínos/metabolismo , Animais , Peso Corporal/fisiologia , Bovinos/anatomia & histologia , Modelos Biológicos , Tamanho do Órgão/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Carneiro Doméstico/anatomia & histologia , Especificidade da Espécie , Suínos/anatomia & histologia
2.
Nat Rev Cardiol ; 17(1): 52-63, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31366922

RESUMO

Flowing blood generates a frictional force called shear stress that has major effects on vascular function. Branches and bends of arteries are exposed to complex blood flow patterns that exert low or low oscillatory shear stress, a mechanical environment that promotes vascular dysfunction and atherosclerosis. Conversely, physiologically high shear stress is protective. Endothelial cells are critical sensors of shear stress but the mechanisms by which they decode complex shear stress environments to regulate physiological and pathophysiological responses remain incompletely understood. Several laboratories have advanced this field by integrating specialized shear-stress models with systems biology approaches, including transcriptome, methylome and proteome profiling and functional screening platforms, for unbiased identification of novel mechanosensitive signalling pathways in arteries. In this Review, we describe these studies, which reveal that shear stress regulates diverse processes and demonstrate that multiple pathways classically known to be involved in embryonic development, such as BMP-TGFß, WNT, Notch, HIF1α, TWIST1 and HOX family genes, are regulated by shear stress in arteries in adults. We propose that mechanical activation of these pathways evolved to orchestrate vascular development but also drives atherosclerosis in low shear stress regions of adult arteries.


Assuntos
Aterosclerose/genética , Endotélio Vascular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Mecanotransdução Celular/genética , Animais , Aterosclerose/metabolismo , Aterosclerose/fisiopatologia , Endotélio Vascular/fisiopatologia , Predisposição Genética para Doença , Humanos , Neovascularização Fisiológica/genética , Fenótipo , Fluxo Sanguíneo Regional , Fatores de Risco , Estresse Mecânico , Remodelação Vascular/genética
3.
Vasc Endovascular Surg ; 54(1): 5-11, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31506033

RESUMO

INTRODUCTION: High flow rates may develop in arteriovenous fistula (AVF), resulting in clinical syndromes of steal, aneurysmal fistula, or high-output cardiac failure. Various techniques with varying success have been advocated to treat this difficult problem. We present a hemodynamically validated novel banding technique. METHODS: We designed a computational fluid dynamic (CFD) model of the native high-flow AVF and tested various juxta-anastomotic venous diameters to determine the effect on AVF blood flow and pressure. We translated this principle in our banding technique, wherein adjustable banding was performed in conjunction with ultrasound-guided brachial artery flow measurement to determine the optimal band diameter. Polyurethane patch was used to fashion the adjustable band. Patient demographics, AVF flow parameters pre- and postintervention, operative intervention, and ultrasound follow-up data were collected prospectively. RESULTS: Our CFD testing demonstrated that the band diameter needed to achieve optimal distal blood pressure and preserve AVF flow depending on blood pressure, end capillary pressure, venous pressure, and vascular diameters. Five patients subsequently underwent dynamic banding of symptomatic high-flow AVF. Mean brachial artery blood flow rates pre- and postbanding were 2964 mL/min (confidence interval [CI]: 1487-4440 mL/min) and 1099 mL/min (CI: 571.7-1627 mL/min), respectively (P = .01). All patients had symptomatic improvement, and at a mean follow-up of 1 year, this benefit was sustained with no AVF thrombosis or loss. CONCLUSION: Adjustable dynamic band using ultrasound-guided brachial artery flow shows promising results in producing accurate AVF blood flow reduction with sustained efficacy in the short term for patients with symptomatic high-flow AVF.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Artéria Braquial/fisiopatologia , Hemodinâmica , Complicações Pós-Operatórias/cirurgia , Diálise Renal , Adolescente , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Artéria Braquial/diagnóstico por imagem , Simulação por Computador , Humanos , Ligadura , Pessoa de Meia-Idade , Modelos Cardiovasculares , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/fisiopatologia , Estudos Prospectivos , Fluxo Sanguíneo Regional , Reoperação , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia de Intervenção
4.
Vasc Endovascular Surg ; 54(1): 80-84, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31533547

RESUMO

Brachial artery pseudoaneurysms (BAPs) are rare but could lead to complications of high morbidity. We report a case of a BAP presenting with hand ischemia and median nerve neuropathy nearly a decade after the inciting iatrogenic trauma, successfully treated with excision and direct repair. This report highlights that untreated pseudoaneurysms can be indolent and present late with both symptoms of embolization and local compression.


Assuntos
Falso Aneurisma/etiologia , Artéria Braquial/lesões , Doença Iatrogênica , Isquemia/etiologia , Flebotomia/efeitos adversos , Extremidade Superior/irrigação sanguínea , Lesões do Sistema Vascular/etiologia , Idoso de 80 Anos ou mais , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/fisiopatologia , Falso Aneurisma/cirurgia , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/fisiopatologia , Artéria Braquial/cirurgia , Humanos , Isquemia/diagnóstico por imagem , Isquemia/fisiopatologia , Isquemia/cirurgia , Masculino , Neuropatia Mediana/etiologia , Fluxo Sanguíneo Regional , Fatores de Tempo , Resultado do Tratamento , Lesões do Sistema Vascular/diagnóstico por imagem , Lesões do Sistema Vascular/fisiopatologia , Lesões do Sistema Vascular/cirurgia
5.
Urologiia ; (5): 132-135, 2019 Dec.
Artigo em Russo | MEDLINE | ID: mdl-31808648

RESUMO

Three basic theories of the development of an overactive bladder that have experimental and clinical evidences have been described, including neurogenic, myogenic, and urothelial. Based on the results of the literature analysis, the authors suggested the existence of detrusor ischemic disease as a result of compressive impairment of its blood flow due to incomplete or short-term relaxation under overactivity or hydraulic compression of the vessels by excessive urine volume in case of hypoactive bladder.


Assuntos
Isquemia/fisiopatologia , Doenças da Bexiga Urinária/etiologia , Doenças da Bexiga Urinária/terapia , Bexiga Urinária/irrigação sanguínea , Hemodinâmica , Humanos , Contração Muscular/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Bexiga Urinária/fisiopatologia , Obstrução do Colo da Bexiga Urinária/complicações , Micção/fisiologia , Urodinâmica/fisiologia , Urotélio
6.
Anticancer Res ; 39(12): 6603-6620, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31810926

RESUMO

BACKGROUND: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. MATERIALS AND METHODS: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. RESULTS: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. CONCLUSION: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.


Assuntos
Simulação por Computador , Pancreaticoduodenectomia , Veia Porta/cirurgia , Veia Cava Inferior/transplante , Aloenxertos , Anastomose Cirúrgica/métodos , Animais , Cadáver , Feminino , Hemodinâmica , Masculino , Tamanho do Órgão , Tratamentos com Preservação do Órgão , Veia Porta/anatomia & histologia , Veia Porta/diagnóstico por imagem , Veia Porta/fisiologia , Complicações Pós-Operatórias/etiologia , Piloro , Procedimentos Cirúrgicos Reconstrutivos/métodos , Fluxo Sanguíneo Regional , Suínos , Coleta de Tecidos e Órgãos , Ultrassonografia , Veia Cava Inferior/anatomia & histologia , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/fisiologia , Trombose Venosa/etiologia
7.
Invest Ophthalmol Vis Sci ; 60(14): 4830-4837, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31747685

RESUMO

Purpose: We investigate macular perfusion and the systemic and ocular associations in a population-based setting. Methods: In this cross-sectional study, 2018 adults residing in Hong Kong underwent detailed ophthalmic examinations after consenting to participate. Macular perfusion was measured with optical coherence tomography angiography (OCTA) using the split-spectrum amplitude decorrelation angiography algorithm. The parafoveal flow index and vessel area density were quantified using automated custom-built software. Results: Of the 2018 participants, the OCTA measurements were available for 1940, and 1631 (84.1%) had good quality scans. The right eyes of these 1631 participants (43.1% men) were included for final analysis. Mean age was 49.8 years (range, 18-92 years). Mean global macular vessel density was 47.3% and 55.1% for the superficial and deep retinal layers, respectively. In multivariate analysis, lower superficial vessel density remained significantly associated with lower signal strength index (SSI; P < 0.001, standardized ß = 0.607) and male sex (P < 0.001, ß = 0.162), and borderline associated with older age (P = 0.09, ß = -0.045) and longer axial length (AL; P = 0.09, ß = -0.037), while lower deep layer vessel density was significantly associated with lower SSI (P < 0.001, standardized ß = 0.667), longer AL (P < 0.001, ß = -0.097), and higher creatinine (P < 0.001, ß = -0.072). Conclusions: This large population-based study provided normative OCTA data of macular vessel density and demonstrated that a lower superficial retinal vessel density was significantly associated with lower SSI and male sex, while a lower deep layer retinal vessel density was significantly associated with lower SSI, longer AL, and higher level of creatinine. These associations must be considered when interpreting clinical quantitative OCTA data.


Assuntos
Angiofluoresceinografia , Macula Lutea/irrigação sanguínea , Vasos Retinianos/anatomia & histologia , Tomografia de Coerência Óptica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Capilares/anatomia & histologia , Capilares/diagnóstico por imagem , Creatinina/sangue , Estudos Transversais , Feminino , Angiofluoresceinografia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Fluxo Sanguíneo Regional/fisiologia , Retina/fisiologia , Vasos Retinianos/diagnóstico por imagem , Lâmpada de Fenda , Tomografia de Coerência Óptica/métodos , Adulto Jovem
8.
Invest Ophthalmol Vis Sci ; 60(14): 4865-4871, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31747687

RESUMO

Purpose: To evaluate the perfusion status of the retina and choriocapillaris in the area of laser scars on swept-source optical coherence tomography angiography (OCTA) images of eyes previously treated with panretinal photocoagulation (PRP). Methods: Cross-sectional exploratory analysis of swept-source OCTA images, which were retrospectively reviewed for laser scars. The appearance of the capillary networks in the area of previous laser were evaluated following a three-step grading system (normal/sparse/missing capillary network). The superficial and deep capillary plexus of the retina and the choriocapillaris were graded separately. Results: A total of 3140 laser scars in 54 eyes of 31 patients (13 female, mean age 57 ± 12 years) were included in this analysis. In the retina, 6.8% of the superficial and deep capillary network in the area evaluated appeared normal, 58% and 56% sparse, and 35% and 37% missing. Capillary dropout in the retina was not restricted to the area of prior laser treatment. The choriocapillaris decorrelation signal was either sparse (61%) or completely missing (38%) within the laser scar area. The perfusion of the choriocapillaris appeared normal in the area adjacent to laser scars. Conclusions: Capillary non-perfusion in the choriocapillaris was found within the laser scar area. Laser treatment seems to cause sustained non-perfusion of choriocapillaris in the area treated.


Assuntos
Corioide/irrigação sanguínea , Cicatriz/fisiopatologia , Retinopatia Diabética/fisiopatologia , Fotocoagulação a Laser , Vasos Retinianos/fisiologia , Idoso , Capilares/fisiologia , Cicatriz/diagnóstico , Estudos Transversais , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/cirurgia , Feminino , Angiofluoresceinografia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/fisiologia , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos
9.
J Vasc Res ; 56(6): 296-307, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31671424

RESUMO

In this study, using fluid-structure interaction (FSI), 3-dimensional blood flow in an aneurysm in the circle of Willis - which is located in the middle cerebral artery (MCA) - has been simulated. The purpose of this study is to evaluate the effect of a partly blocked vessel on an aneurysm. To achieve this purpose, two cases have been investigated using the FSI method: in the first case, an ideal geometry of aneurysm in the MCA has been simulated; in the second case, modeling is performed for an ideal geometry of the aneurysm in the MCA with a partly blocked vessel. All boundary conditions, properties and modeling methods were considered the same for both cases. The only difference between the two cases was that part of the MCA parent artery was blocked in the second case. In order to consider the hyperelastic property of the wall and the non-Newtonian properties of the blood, the Mooney-Rivlin model and the Carreau model have been used, respectively. In the second case, the Von Mises stress in the peak systole is 26% higher than in the first case. With regard to the high amount of Von Mises stress, the risk of rupture of the aneurysm is higher in this case. In the second case, the maximum wall shear stress (WSS) is 12% higher than in the first case. And maximum displacement in the second case is also higher than in the first. So, the risk of growth of the aneurysm is higher in cases with a partly blocked vessel.


Assuntos
Circulação Cerebrovascular , Círculo Arterial do Cérebro/fisiopatologia , Simulação por Computador , Infarto da Artéria Cerebral Média/fisiopatologia , Aneurisma Intracraniano/fisiopatologia , Modelos Cardiovasculares , Idoso , Velocidade do Fluxo Sanguíneo , Angiografia Cerebral/métodos , Círculo Arterial do Cérebro/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Progressão da Doença , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Fluxo Sanguíneo Regional
10.
Invest Ophthalmol Vis Sci ; 60(14): 4574-4582, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675074

RESUMO

Purpose: We studied the topographic distribution of contractile protein in different orders of the human macular microvasculature to further understanding of the sites for capillary blood flow regulation. Methods: Nine donor eyes from eight donors were cannulated at the central retinal artery and perfusion labeled for alpha smooth muscle actin (αSMA) and filamentous actin (F-actin). Confocal images were collected from the macula region, viewed, projected, and converted to a 255 grayscale for measurements. The mean intensity was measured for macular arterioles, venules, and capillary segments. The diameter of each vessel segment measured was recorded. The normalized mean intensity values from all images were ranked according to vessel types and size with a total of nine categories. Results: F-actin was present throughout the macular microvasculature whereas αSMA labeling showed variations. Overall, αSMA has a more prominent presence in the macular arterioles than in the macular capillaries and venules, and αSMA strongly labeled the smaller macular arterioles. Some capillaries also labeled positive for αSMA, including some of the capillaries in the innermost capillary ring surrounding the foveola. It was weakly present in the capillaries on the venous side and larger venules. In the larger macular arterioles closer to 100 µm in diameter, αSMA labeling was weakly present and not as ubiquitous as in the smaller arterioles. Conclusions: Nonuniform distribution of contractile proteins in the different types, orders, and sizes of macular microvasculature indicates that these vessels may have different contractile capability and roles in macular flow regulation.


Assuntos
Actinas/metabolismo , Artéria Retiniana/metabolismo , Veia Retiniana/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteríolas/metabolismo , Endotélio Vascular/metabolismo , Feminino , Humanos , Masculino , Microscopia Confocal , Microvasos , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/fisiologia , Doadores de Tecidos , Vênulas/metabolismo
11.
Khirurgiia (Mosk) ; (11): 24-28, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31714526

RESUMO

OBJECTIVE: To study the causes of recirculation syndrome and optimize surgical correction. MATERIAL AND METHODS: There were 2329 procedures of formation and restoration of permanent vascular access in 2109 patients for the period from 1998 to 2018. Recirculation syndrome occurred in 66 (3.1%) patients. Instrumental diagnosis of the causes of recirculation syndrome included Doppler ultrasound of permanent vascular access (100%) and angiography in accordance with indications. All patients were divided into 4 groups. The first group included 39 (59.1%) patients with native arteriovenous fistula. The second group included 12 (18.2%) patients with high arteriovenous fistula (between the brachial artery and the cephalic vein). The third group included 10 (15.1%) patients with major vein transposition. Synthetic prosthesis to create an arteriovenous fistula was used in the fourth group (n=5, 7.6%). RESULTS: In the first group, recirculation syndrome was caused by the presence of a large branch in close proximity to the arteriovenous anastomosis, its combination with significant stenosis of the anastomosis, hypoplasia of the outflow pathways of the fistulous vein. In the second group, the reasons were subclavian vein stenosis and dilated tributaries of the saphenous veins. In the third group, the main cause of recirculation syndrome was major vein stenosis in the upper third of the shoulder. In the fourth group, recirculation syndrome was caused by stenosis of the prosthetic-venous anastomosis. CONCLUSION: Recirculation syndrome in hemodialysis patients is usually caused by malfunction of permanent vascular access. Ultrasound or angiography may be successfully used to diagnose dysfunction. Effective treatment of this problem implies surgical or endovascular correction of permanent vascular access.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Constrição Patológica/complicações , Falência Renal Crônica/terapia , Diálise Renal , Derivação Arteriovenosa Cirúrgica/métodos , Humanos , Fluxo Sanguíneo Regional , Síndrome , Resultado do Tratamento , Grau de Desobstrução Vascular , Veias/patologia
12.
Clin Interv Aging ; 14: 1461-1469, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31616137

RESUMO

Introduction: A 91-year-old sedentary man presenting exhaustion, lower-limb weakness, hypertension, and history of multiple falls was diagnosed with sarcopenia - appendicular skeletal muscle mass index (ASM) of 7.10 kg/m2. Purpose: To investigate the effects of strength training performed with low intensity in isolation (LI) or with blood flow restriction (LI-BFR) on strength, muscle mass, IGF-1, endothelial function, microcirculation, inflammatory biomarkers, and oxidative stress. Methods: In the first 3 months, LI was performed with intensity corresponding to 30% of 1 repetition maximum, followed by 1 month of inactivity, and another 3 months of LI-BFR (similar load than LI concomitant to BFR equivalent to 50% of resting systolic blood pressure). Results: LI-BFR, but not LI improved muscle mass, ASM, handgrip strength, isokinetic peak torque, IL-6, and IGF-1. Endothelial function, red blood cell velocity, and concentrations of C-reactive protein, and soluble intercellular adhesion molecules-1 improved after both LI and LI-BFR. Endothelin-1 and oxidative stress increased after LI-BFR, and lowered after LI. Conclusion: LI-BFR, but not LI improved strength, muscle mass, IGF-1, endothelial function, and selected inflammatory markers in a nonagenarian sarcopenic patient. These results are promising and suggest that LI-BFR should be considered as an alternative to prevent muscle loss and improve functional fitness in frail older populations.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento de Resistência/métodos , Sarcopenia/terapia , Idoso de 80 Anos ou mais , Exercício/fisiologia , Força da Mão , Humanos , Masculino , Fluxo Sanguíneo Regional , Sarcopenia/prevenção & controle
13.
J Cardiovasc Surg (Torino) ; 60(6): 749-754, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31640318

RESUMO

BACKGROUND: In descending thoracic aortic aneurysm (DTAA) or thoracoabdominal aortic aneurysm (TAAA) surgery, though proximal anastomosis using deep hypothermic circulatory arrest (DHCA) is often selected, there are issues surrounding brain and heart protection. In this study, the usefulness of concomitant upper body perfusion via transapical aortic cannulation during deep hypothermic surgery was examined. METHODS: Between October 2014 and May 2019, 5 patients (Crawford extent II chronic dissection, N.=3; extent IV aneurysms, N.=1; DTAA, N.=1) underwent DTAA/TAAA repair under deep hypothermia using transapical aortic perfusion. A proximal anastomosis and artery of Adamkiewicz (AKA) reconstruction were performed under continuous perfusion of the upper and lower body at 20 °C. RESULTS: The time from aortic cross-clamping to proximal anastomosis was 69±33 minutes, and it took 86±47 minutes to AKA reperfusion. There was no spinal cord ischemic injury or brain or heart complications. One patient required tracheostomy, and the average postoperative intubation time for the other patients was 57±52 hours. All patients were discharged, and the average postoperative hospital stay was 25.6±8.1 days. CONCLUSIONS: Concomitant upper body perfusion by the transapical aortic approach contributes to avoidance of brain and heart complications and maintaining spinal cord circulation under deep hypothermic DTAA/TAAA surgery.


Assuntos
Aneurisma Dissecante/cirurgia , Aneurisma da Aorta Abdominal/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular , Parada Circulatória Induzida por Hipotermia Profunda , Perfusão/métodos , Adulto , Aneurisma Dissecante/diagnóstico por imagem , Aneurisma Dissecante/fisiopatologia , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Torácica/diagnóstico por imagem , Aneurisma da Aorta Torácica/fisiopatologia , Implante de Prótese Vascular/efeitos adversos , Doença Crônica , Parada Circulatória Induzida por Hipotermia Profunda/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perfusão/efeitos adversos , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/prevenção & controle , Fluxo Sanguíneo Regional , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
14.
J Cardiovasc Surg (Torino) ; 60(6): 742-748, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31599142

RESUMO

BACKGROUND: Our aim was to investigate the impact of the non-skeletonized (pedicled) versus the skeletonized left internal mammary (LIMA) harvesting technique on the postoperative sternal and parasternal skin perfusion in patients undergoing coronary artery bypass grafting (CABG), as compared to patients undergoing non-CABG heart surgery. METHODS: We included 142 patients who underwent non-bypass (N.=39) or CABG surgery (N.=103). CABG cases were differentiated according to the LIMA harvesting technique: skeletonized (N.=74) or non-skeletonized (N.=29). Parasternal and sternal skin perfusion measurements via a Laser Doppler Imaging tool were performed on the preoperative day and 5-7 days postoperatively, using a grid of 15 spatially segregated measurement points across the chest and normalization to a distinct reference point. Data were analyzed retrospectively. RESULTS: In the CABG group, the non-skeletonized LIMA harvesting resulted in a near-significant (P=0.057, two-sided Student t-test, 95% CI -[0.111, 0.002]), and the skeletonized LIMA harvesting in a significant (P< 0.001, 95% CI [-0.096, -0.032]) post-surgical decrease of left-sided parasternal skin perfusion in arbitrary perfusion units (APU), as compared to right-sided parasternal skin perfusion. No corresponding differences were found for the non-bypass group (P=0.5, 95% CI [-0.065, 0.033]). The harvesting techniques did not yield significantly different post-surgical parasternal skin perfusion measures in the CABG group (P=0.6). CONCLUSIONS: Measurement of parasternal skin perfusion using Laser Doppler Imaging is feasible. Both harvesting techniques resulted in a reduced parasternal/sternal skin perfusion upon removal of the internal mammary artery.


Assuntos
Ponte de Artéria Coronária/efeitos adversos , Fluxometria por Laser-Doppler , Artéria Torácica Interna/transplante , Imagem de Perfusão/métodos , Pele/irrigação sanguínea , Coleta de Tecidos e Órgãos/efeitos adversos , Idoso , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Fatores de Risco , Esterno , Resultado do Tratamento
15.
J Cardiovasc Surg (Torino) ; 60(6): 652-661, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31603292

RESUMO

INTRODUCTION: Hyperspectral imaging (HSI) is a noninvasive technique for transcutaneous measurements of tissue perfusion. This study (1) provides a review of the current literature on HSI for tissue perfusion measurements of the lower leg and (2) introduces a standardized measurement protocol for HSI measurements with a portable system. EVIDENCE ACQUISITION: A literature search was performed for studies on tissue perfusion measurements with HSI in the lower extremity. A standardized protocol was developed to perform HSI measurements in 43 healthy volunteers at the plantar side of the foot and at the lateral side of the calf, with 3 consecutive hyperspectral images at each location. EVIDENCE SYNTHESIS: The literature review identified 9 studies, including 2 of healthy volunteers, 4 of patients with diabetes mellitus, and 3 of patients with peripheral arterial disease. In 5 of 7 patient studies, HSI values were associated with severity of disease or wound healing. In our study, the healthy volunteers' HSI values for oxyhemoglobin, deoxyhemoglobin, and oxygen saturation were (mean±SD) 82.8±24, 55.7±15.7, and 59.2±11.7, respectively, at the plantar surface of the foot, and 40.8±11, 38.0±7.8, and 51.7±10.5, respectively, at the lateral side of the calf. HSI values differed significantly between the calf and plantar locations. Intraoperator reliability between the 3 consecutive images ranged from 81% to 89%. CONCLUSIONS: Limited evidence indicates that HSI is associated with severity of peripheral arterial disease and diabetes mellitus, and with wound healing. Hyperspectral images with a portable system can be taken with high precision when a standardized measurement protocol is used. However, differences exist at several locations at the lower extremity, so each measurement location should be used as its own reference when consecutive measurements are performed during follow-up. More studies with larger patient cohorts should be performed before HSI can be incorporated as standard tool in the diagnostic armamentarium of the vascular specialist.


Assuntos
Extremidade Inferior/irrigação sanguínea , Imagem de Perfusão/métodos , Doença Arterial Periférica/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Microcirculação , Imagem de Perfusão/normas , Doença Arterial Periférica/fisiopatologia , Valor Preditivo dos Testes , Prognóstico , Fluxo Sanguíneo Regional , Índice de Gravidade de Doença , Análise Espectral , Cicatrização
16.
J Cardiovasc Surg (Torino) ; 60(6): 686-692, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31603296

RESUMO

BACKGROUND: In patients requiring infrageniculate surgical revascularization a single-segment great saphenous vein (SS-GSV) is the optimal conduit. In the absence of a SS-GSV, the small saphenous vein and arm veins can also be used to obtain an all-autologous bypass. The aim of this study was to compare the long-term results of infrageniculate SS-GSV bypasses and spliced vein bypasses in patients with chronic limb-threatening ischemia (CLTI). METHODS: A total of 308 consecutive CLTI patients who underwent a primary infragenicular, autologous bypass between January 2000 and December 2016 were included. The definition of a spliced vein bypass was a graft consisting of at least two venous segments. RESULTS: A SS-GSV graft was used in 235 patients, and a spliced vein graft was used in 73 patients. Significantly more infrapopliteal bypasses were performed in the spliced vein group (P=0.024), and in this group the mean operation time was almost 60 minutes longer (P<0.001). The overall morbidity rate was 44%. The overall 30-day mortality was 3.2%, and overall in-hospital mortality was 4.9%. No significant differences were observed between the groups in mortality, overall morbidity or any specific complication. Comparing the SS-GSV group with the spliced vein group, no significant differences were observed between overall survival (53.2% vs. 45.7%), primary patency (55.5% vs. 53.2%), assisted primary patency (78.5% vs. 76.5%), secondary patency (87.9% vs. 90.6%) and limb salvage (83.3% vs. 82.0%). CONCLUSIONS: The use of infrageniculate spliced vein bypasses for the treatment of CLTI patients results in similar results compared with infrageniculate SS-GSV bypass grafts. A strict surveillance protocol in the first 2 years and a liberal reintervention strategy may result in excellent long-term patency rates.


Assuntos
Isquemia/cirurgia , Extremidade Inferior/irrigação sanguínea , Doença Arterial Periférica/cirurgia , Veia Safena/transplante , Enxerto Vascular/métodos , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Feminino , Mortalidade Hospitalar , Humanos , Isquemia/diagnóstico por imagem , Isquemia/mortalidade , Isquemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Países Baixos , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/mortalidade , Doença Arterial Periférica/fisiopatologia , Fluxo Sanguíneo Regional , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Enxerto Vascular/efeitos adversos , Enxerto Vascular/mortalidade , Grau de Desobstrução Vascular
17.
Clin Exp Rheumatol ; 37 Suppl 119(4): 97-101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31573479

RESUMO

OBJECTIVES: The fingers, toes, and tips of the nose and ears have specialised structural and functional features for thermoregulation, and are the most common areas of Raynaud's phenomenon in systemic sclerosis. Digital thermal monitoring (DTM) of vascular reactivity assesses Doppler ultrasound hyperemic, low frequency, blood velocity of radial artery and fingertip vascular function. Flow mediated dilation (FMD) is an indirect measure of endothelial function, perfusion, and vasodilator ability. In this study, we investigated the cross-sectional correlation of FMD and DTM variables to inform an optimised noninvasive study of SSc endothelial function. A student's T-test was used to compare means of DTM across binary variables. METHODS: Consented SSc registry patients were included in this analysis. The subjects were prepared for FMD and DTM per standardised guidelines. The SSc clinical features were recorded. Spearman's Rank Correlation was used to assess the strength of a relationship FMD and DTM variables. RESULTS: Thirty-four SSc subjects had FMD and DTM performed on the same day. Relative (0.42, p=<0.02), absolute FMD (0.41, p<0.02), and shear rate (0.32, p<0.07) were weakly, but significantly correlated with the DTM. Reactive hyperemia (-0.44, p=0.000) was weakly inversely, but significantly related with DTM. Baseline diameter and flow were not significantly related to the DTM. CONCLUSIONS: This non-invasive study of SSc endothelial function suggests that macrocirculation (including relative and absolute FMD, shear rate, and peak hyperemia) and microcirculatory thermoregulation (characterised by DTM) are significantly correlated, thus warrants further prospective study.


Assuntos
Microcirculação/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Escleroderma Sistêmico , Pele/irrigação sanguínea , Artéria Braquial , Estudos Transversais , Dilatação , Endotélio Vascular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escleroderma Sistêmico/fisiopatologia , Vasodilatação
18.
Acta Cir Bras ; 34(8): e201900804, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618404

RESUMO

PURPOSE: To develop a rabbit model of a short peripheral catheter (SPC) and to observe the effects of different flushing methods on blood vessels. METHODS: Thirty rabbits were randomly divided into three groups (A, B, and C), with ten rabbits per group. In group A, we used pulsed flush; in group B, we used uniform flush; and no treatment was used in group C. RESULTS: We observed that a uniform flush reduced blockage, phlebitis, and exudation compared to a pulsed flush by visual observation. The histopathological examination found that the morphological changes in group A were more severe than in group B and C related to loss of venous endothelial cells, inflammatory cell infiltration, edema, epidermal and chondrocyte degeneration, except for the thrombosis on group B that was more serious than in group A, especially in the distal side of puncture points. The distal region of groups A and B had more inflammatory cell infiltration than the proximal region. Thrombosis was more severe in the distal region than in the proximal region in group B. CONCLUSIONS: The uniform flush produced less damage to the vascular endothelium and surrounding tissues and was superior to the pulsed flush. However, the uniform flush is prone to thrombosis.


Assuntos
Vasos Sanguíneos/patologia , Cateterismo Periférico/métodos , Animais , Cateterismo Periférico/efeitos adversos , Modelos Animais de Doenças , Orelha/irrigação sanguínea , Células Endoteliais , Endotélio Vascular/patologia , Endotélio Vascular/ultraestrutura , Masculino , Flebite/etiologia , Coelhos , Distribuição Aleatória , Fluxo Sanguíneo Regional
19.
J Vasc Res ; 56(5): 241-254, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31536996

RESUMO

PURPOSE: Atherosclerosis in the carotid arteries is a common cause of ischemic stroke. We examined atherogenesis in the left carotid artery with and without interrupted blood flow of C57BL/6 (B6) and C3H-Apoe-deficient (Apoe-/-) mouse strains. METHODS: Blood flow was interrupted by ligating the common carotid artery near its bifurcation in one group of mice and another group was not interrupted. RESULTS: Without interference with blood flow, C3H-Apoe-/- mice developed no atherosclerosis in the carotid artery, while B6-Apoe-/- mice formed advanced atherosclerotic lesions (98,019 ± 10,594 µm2/section) after 12 weeks of a Western diet. When blood flow was interrupted by ligating the common carotid artery near its bifurcation, C3H-Apoe-/- mice showed fatty streak lesions 2 weeks after ligation, and by 4 weeks fibrous lesions had formed, although they were smaller than in B6-Apoe-/- mice. Neutrophil adhesion to endothelium and infiltration in lesions was observed in ligated arteries of both strains. Treatment of B6-Apoe-/- mice with antibody against neutrophils had little effect on lesion size. CONCLUSIONS: These findings demonstrate the dramatic influences of genetic backgrounds and blood flow on atherogenesis in the carotid artery of hyperlipidemic mice.


Assuntos
Doenças das Artérias Carótidas/etiologia , Artéria Carótida Primitiva/fisiopatologia , Hiperlipidemias/complicações , Placa Aterosclerótica , Animais , Doenças das Artérias Carótidas/genética , Doenças das Artérias Carótidas/patologia , Doenças das Artérias Carótidas/fisiopatologia , Artéria Carótida Primitiva/patologia , Artéria Carótida Primitiva/cirurgia , Modelos Animais de Doenças , Feminino , Predisposição Genética para Doença , Hiperlipidemias/genética , Ligadura , Masculino , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Fluxo Sanguíneo Regional , Especificidade da Espécie , Fatores de Tempo
20.
J Vasc Res ; 56(5): 255-266, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31533112

RESUMO

INTRODUCTION: In spite of the great relevance of abdominal aortic aneurysm, its etiopathogenesis is not fully understood. The biomechanical and histological study of the aortic wall may contribute to this elucidation. METHODS: Seventy-five male Wistar rats were divided into 4 groups: control (CG), smoker (SG), diabetic (DG), and diabetic + smoker (DSG). The SG and DSG rats were exposed to cigarette smoke for 30 min/day, 5 days a week. Diabetes was induced by the intravenous injection of streptozotocin. After 16 weeks, the abdominal aorta was collected for biomechanical, histological, and matrix metalloproteinase 2 (MMP-2) activity analyses. RESULTS: The valid biomechanical tests of 52 specimens were analyzed: 11 in the CG, 10 in the DG, 16 in the SG, and 15 in the DSG. The biomechanical analysis of the fragments showed no differences between the control, DG, SG, and DSG. Collagen deposition also did not present a significant difference between the studied groups. The total count of elastic fibers was higher in diabetic rats (DG and DSG) than in the SG. The inflammatory response observed in all experimental groups was significantly more intense than in the CG. Compared to the DSG, MMP-2 activity showed a significant decrease in the DG. CONCLUSIONS: Resistance and elasticity did not present a difference between the CG and the DG, SG, and DSG. Compared to the CG, the total count of elastic fibers, fragmentation of the elastic lamina, pericellular matrix deposition, and cell loss/substitution in the tunica media showed significant alterations in the aortic walls of the DG, SG, and DSG. MMP-2 activity was lower in the DG aorta than in the DSG aorta.


Assuntos
Aorta Abdominal/patologia , Aneurisma da Aorta Abdominal/etiologia , Diabetes Mellitus Experimental/complicações , Fumaça/efeitos adversos , Produtos do Tabaco/efeitos adversos , Animais , Aorta Abdominal/metabolismo , Aorta Abdominal/fisiopatologia , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/patologia , Aneurisma da Aorta Abdominal/fisiopatologia , Fenômenos Biomecânicos , Colágeno/metabolismo , Progressão da Doença , Tecido Elástico/patologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Ratos Wistar , Fluxo Sanguíneo Regional , Fatores de Risco , Estresse Mecânico , Fatores de Tempo
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