Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-06-02T17:42:39Z No. of bitstreams: 2 Dissertação - Joana Estela Rezende Vilela - 2015.pdf: 2631245 bytes, checksum: cc3eb64cd43c485a3a6e07b7034d39e6 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-06-03T11:31:50Z (GMT) No. of bitstreams: 2 Dissertação - Joana Estela Rezende Vilela - 2015.pdf: 2631245 bytes, checksum: cc3eb64cd43c485a3a6e07b7034d39e6 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) / Made available in DSpace on 2016-06-03T11:31:50Z (GMT). No. of bitstreams: 2 Dissertação - Joana Estela Rezende Vilela - 2015.pdf: 2631245 bytes, checksum: cc3eb64cd43c485a3a6e07b7034d39e6 (MD5) license_rdf: 19874 bytes, checksum: 38cb62ef53e6f513db2fb7e337df6485 (MD5) Previous issue date: 2015-07-02 / In Americas million people are carriers of Chagas disease caused by Trypanosoma cruzi. Chronic chagasic cardiopathy is the most severe form of the disease, characterized by lesions in the myocardium associated with inflammation and fibrosis which often evolve to progressive decrease of heart function. Chagas’ disease during aging may have specific aspects that require further studies. The aim of the study was to describe the relationship of angiogenesis and mast cell density with myocardial fibrosis in elderly patients with chronic Chagas' disease. To reach this goal we selected left ventricular fragments of autopsied patients at the Clinical Hospital, Federal University of Triangulo Mineiro. The samples were divided into four groups: elderly with chagasic cardiopathy - 6 (CC elderly); elderly without chagasic cardiopathy - 5 (SC elderly); Non-elderly with chagasic cardiopathy - 5 (no elderly CC); Non-elderly without chagasic cardiopathy - 5 (no elderly SC). Picrosirius red staining was performed for quantifying the percentage of collagen in common light and 10x magnification. Immunohistochemistry was performed to obtain the mast cell density, using antitriptase monoclonal antibody, and the density of blood vessels, using CD34 monoclonal antibody. The samples were evaluated under common light and at 40x magnification. The percentage of collagen was significantly higher in the elderly CC group compared to the other groups (p = 0.003). The density of mast cells was higher in elderly CC group, but no significant difference (p = 0.226). The density of blood vessels was lower in the elderly CC group and no significant difference (p = 0.224). Therefore, in elderly CC group there was more collagen, and also higher density of mast cells and lower density of blood vessels, although not significant, which are probably associated to the etiopathogenesis of myocardial lesions in chronic Chagas' disease during aging. / Nas Américas milhões de pessoas são portadoras da doença de Chagas causada pelo Trypanosoma cruzi. A cardiopatia chagásica crônica é a forma mais grave da doença, caracterizada por lesões no miocárdio associadas a processo inflamatório e fibrose que muitas vezes evoluem para progressiva diminuição das funções cardíacas. A doença de Chagas durante o envelhecimento pode ter aspectos específicos que precisam ser mais claramente entendido. O objetivo do estudo foi descrever a relação da angiogênese e da densidade de mastócitos com a fibrose miocárdica em idosos portadores de cardiopatia chagásica crônica. Para tanto foram selecionados fragmentos do ventrículo esquerdo de pacientes autopsiados no Hospital das Clínicas da Universidade Federal do Triângulo Mineiro. Formou-se quatro grupos, idosos com cardiopatia chagásica – 6 (Idoso CC); idosos sem cardiopatia chagásica – 5 (Idoso SC); Não-idosos com cardiopatia chagásica – 5 (não idoso CC); Não-idosos sem cardiopatia chagásica - 5 (não idoso SC). Realizou-se a técnica de picrosirius para quantificação da porcentagem do colágeno sob luz comum e objetiva de 10x. A imunohistoquímica foi realizada para obtenção da densidade de mastócitos utilizando o anticorpo monoclonal antitriptase, e para a densidade de vasos sanguíneos o anticorpo monoclonal CD34, ambas foram avaliadas sob luz comum e objetiva de 40x. A porcentagem de colágeno foi significativamente maior no grupo de idosos CC, quando comparada aos outros grupos (p=0,003). A densidade de mastócitos foi maior no grupo de idosos CC, mas sem diferença significativa (p=0,226). A densidade de vasos sanguíneos foi menor no grupo de idosos CC e sem diferença significativa (p=0,224). Portanto, foi verificada no grupo de idosos CC maior quantidade de colágeno, e ainda, maior densidade de mastócitos e menor densidade de vasos sanguíneos, embora não significativa, que provavelmente estão relacionados com a etiopatogênese das lesões miocárdicas na cardiopatia chagásica crônica durante o envelhecimento.

Made available in DSpace on 2015-09-25T12:18:38Z (GMT). No. of bitstreams: 1 Belchior de Medeiros Lucena Parte 1.pdf: 1755075 bytes, checksum: 805804d176c5c8e065af77494d6c1f53 (MD5) Previous issue date: 2012-03-14 / Objective: To analyze the morbidity and mortality from external causes in patients treated at the Regional Hospital of Emergency and Trauma in Campina Grande, PB. Methodology: This was a cross-sectional descriptive and analytical study using secondary data. We analyzed medical records of 9,734 patients treated at between January 2009 and December 2009, being selected in 1889(19,4%) confirmed cases of patients affected by external causes that were distributed according to etiology. The data collection tool was formulated according to the information in medical records. The ethical aspects of research with human subjects were met: the project was approved by the ethical committee for research of UEPB and also was authorized by the direction of the institution. In the data analysis were used techniques of descriptive statistics (absolute and percentage distributions) and inferential (chi-squared or Fisher's exact test, likelihood test, confidence intervals and odds ratio), adopting a significance level of 5,0%, with confidence intervals of 95.0%. The statistical program used to prepare the database and make the statistical calculations was SPSS (Statistical Package for Social Sciences) version 15. Results: The age of patients ranged from 0 to 99 years, had a mean of 30.74 years, median 27.00 years and standard deviation of 19.80 years. Of the 1789 surveyed, 1376 (76.9%) were male and 413 (23.1%) were female. The higher frequency of cases occurred on Sunday (18.6%) and the others days corresponded to percentages ranging from 11.6% to 15.4%. The category of 18:01 to 24:00 h showed the highest frequency of cases (37.9%). The most frequent etiologies were motorcycle accident (20.8%), falls (19.8%), burns (11.2%), gunshots(10.5%), snake bite (8.5%) and stab wound (8.3%). The body regions most affected were the lower limbs (36.2%), upper limbs (32.4%), chest (16.8%), abdomen (14.2%) and face (12.0%). A significant association was observed between violence and the age of the second, third and fourth decades of life and among those surveyed were male (24.4% vs 6.5%). Conclusions: The subjects were male, young, in the age of the second, third and fourth decades of life are more susceptible to external causes and particularly violence and traffic accidents. Vascular lesions are uncommon and are associated with longer hospitalization and higher mortality. / Objetivo: Analisar a morbimortalidade por causas externas em pacientes atendidos no Hospital Regional de Urgência e Trauma de Campina Grande/PB. Metodologia: Foi realizado um estudo transversal, descritivo e analítico com dados secundários. Foram analisados 9734 prontuários médicos de pacientes atendidos entre janeiro de 2009 e dezembro de 2009, sendo selecionados 1889 (19,4%) casos confirmados de pacientes acometidos por causas externas e distribuídos segundo a etiologia. O instrumento de coleta de dados foi formulado de acordo com as informações existentes no prontuário médico. O projeto foi aprovado pelo comitê de ética em pesquisa da UEPB e foi autorizado pela direção da instituição. Na análise dos dados foram utilizadas técnicas de estatística descritiva (distribuições absolutas e percentuais) e inferencial (Testes do Qui-quadrado de Pearson ou Exato de Fisher, teste de Verossimilhança, intervalos de confiança e o Odds Ratio), sendo adotado um nível de significância de 5,0% e os intervalos com confiabilidade de 95,0%. O programa estatístico utilizado para elaboração do banco de dados e realização dos cálculos estatísticos foi o SPSS (Statistical Package for the Social Sciences) na versão 15. Resultados: A idade dos pesquisados variou de 0 a 99 anos, teve média de 30,74 anos, mediana de 27,00 anos e desvio padrão de 19,80 anos. Dos 1789 pesquisados, 1376 (76,9%) eram do sexo masculino e 413 (23,1%) eram do sexo feminino. A maior frequência de casos ocorreu no dia de domingo (18,6%) e os demais dias corresponderam a percentuais que variaram de 11,6% a 15,4%. A categoria de 18:01 h a 24:00 h foi a que apresentou a maior frequência de casos (37,9%). As etiologias mais frequentes foram acidente de moto (20,8%), queda (19,8%), queimaduras (11,2%), PAF (10,5%), picada de cobra (8,5%) e ferimento por arma branca (8,3%). Os locais do corpo mais atingidos foram membros inferiores (36,2%), membros superiores (32,4%), tórax (16,8%), abdômen (14,2%) e face (12,0%). Foi observada associação significativa da violência com as faixas etárias da segunda, terceira e quarta décadas de vida e entre os pesquisados do sexo masculino (24,4% versus 6,5%). Conclusões: Os indivíduos do sexo masculino, jovens, nas faixas etárias da segunda, terceira e quarta décadas de vida estão mais susceptíveis às causas externas e sobretudo à violência e acidentes de transporte. As lesões vasculares são pouco frequentes e estão associadas com maior tempo de internação e maior mortalidade.

As imagens de angiografia por ressonância magnética (angio-RM) ou por tomografia computadorizada (angio-TC) permitem uma análise minuciosa das redes vasculares. A segmentação de redes vasculares a partir de tais imagens é uma das tarefas iniciais no diagnóstico de doenças vasculares como estenoses ou aneurismas. Porém, a grande diversidade de arquiteturas dos vasos dificulta a validação dos algoritmos de segmentação. Assim, a construção de redes vasculares sintéticas realistas permitem validar novas metodologias de segmentação de vasos. Este trabalho descreve uma metodologia de geração de redes vasculares sintéticas em três dimensões utilizando sistemas de Lindenmayer (L-systems) estocásticos. Para atingir esse objetivo, foram implementados um analisador léxico, um analisador sintático e um gerador de L-systems para a criação de vasos sintéticos baseado em gramáticas. A parametrização destas gramáticas possibilita a simulação de características naturais de vasos reais como o ângulo de bifurcação, comprimento, diâmetro médio e possibilita a simulação de anomalias vasculares. As expressões resultantes são utilizadas para criar imagens angiográficas sintéticas que simulam a distribuição de intensidades dos vasos em imagens angio-RM e angio-TC reais. As redes vasculares sintéticas podem também ser delimitadas por superfícies 3D arbitrárias de forma similar à geometria de órgãos. A flexibilidade de parametrização e natureza estocástica desta metodologia faz com que ela se torne uma ferramenta ideal para a validação de algoritmos de segmentação de vasos em imagens angiográficas. / Magnetic resonance angiography (MRA) or computed tomography angiography (CTA) images allow for a thorough analysis of the blood vessels. Vessel segmentation from MRA or CTA is thus the primary task in the diagnosis of vascular diseases such as stenosis and aneurysms. The wide architectural variability of the blood vessels, however, hinders the validation of vascular segmentation methods. The construction of synthetic realistic vascular architecture trees will aid in the validation of new vessel segmentation methodologies. This thesis describes a three-dimensional synthetic blood vessel generation methodology that employs stochastic Lindenmayer systems (L-systems). For this purpose, we implemented a parser and a generator of L-systems to create grammars that represent blood vessel architectures. The parameterization of the grammar allows one to simulate natural features of real vessels such as bifurcation angle, average length and diameter, and also accounts for vascular anomalies. The resulting expressions are used to create synthetic angiographic images that mimic real vessel intensity distributions in MRA and CTA. Blood vessel growth can also be delimited by arbitrary 3D surfaces that may represent organ geometries. The flexibility in the parameterization and stochastic nature of this methodology makes it an ideal tool for the validation of blood vessel segmentation algorithms from angiographic images.

Neste estudo avaliou-se a ação da Angiotensina II (Ang II) e do bloqueio dos seus receptores AT1 e AT2 no remodelamento da matriz extracelular (MEC) e traçamos o perfil da sinalização intracelular envolvida no processo. O estudo foi feito in vivo em camundongos isogênicos C57Bl/6J submetidos a tratamento durante 7 e 14 dias com doses subpressoras de Ang II, bloqueador do receptor AT1 (Losartan) e uma combinação destes. Os animais foram sacrificados e procedeu-se a coleta de tecidos de artérias (aorta, carótida e femoral), coração, rins e pulmão para análise da síntese e degradação de componentes da MEC. Foram feitas avaliações hemodinâmicas, morfológicas em microscopia de luz, morfométricas, imunohistoquímicas para os componentes da matriz extracelular: colágeno (tipos I, III, IV e VI), fibronectina, tenascina-C, elastina, metaloproteinases (tipos 2 e 9), e quantificação de algumas proteínas ligadas à sinalização intracelular da via das Proteínas quinases ativadas por mitógenos (MAPK - Mitogen-activated protein kinases) usando-se Western Blotting. / In this study we evaluated the action of Angiotensin II (Ang II) and the blockade of AT1 and AT2 receptors in the remodeling of extracellular matrix (ECM) and outlines the process involved in intracellular signaling. The study was done in vivo in C57Bl/6J inbred mice undergoing treatment for 7 and 14 days subpressor doses of Ang II, AT1 receptor blocker (Losartan) and a combination thereof. The animals were sacrificed and proceeded to collect tissues of arteries (aorta, carotid and femoral arteries), heart, kidneys and lungs for analysis of the synthesis and degradation of ECM components. We assessed hemodynamic, morphological light microscopy, morphometry, immunohistochemistry for extracellular matrix components: collagen (types I, III, IV and VI), fibronectin, tenascin-C, elastin, metalloproteinases (types 2 and 9) and quantification of some proteins related to intracellular signaling pathways of the mitogen-activated protein kinase (MAPK) using Western Blotting.

Made available in DSpace on 2016-05-02T13:54:47Z (GMT). No. of bitstreams: 1 MariaCristinaGomesSouzaFreire-dissertacao.pdf: 2236739 bytes, checksum: 70bf01d25f055de68fe07a8b82e35a80 (MD5) Previous issue date: 2010-08-05 / Wound treatment involves local and systemic aspects developed by professionals from different fields, such as low power laser and propolis. The purpose of this study was to identify and histologically compare the effects of the application of 3 treatments on surgically induced skin wounds in rats: 658 nm low power laser (LPL); propolis; and LPL laser + propolis. One hundred and forty-four male Wistar albino rats (Rattus norvegicus albinus), aged 16 weeks, weighing 350-500g, from the Unifenas Central Biotherium, were used. After general anesthesia with ketamine® (ketamine hydrochloride) / Rompun® (xylazine) (0.2 mL per 100g of animal weight: 50% ketamine and 50% Rompun), the rats were shaved on the back between the shoulder blades, and then submitted to the punch excision of the skin. The animals were divided into seven groups: GL: treated with 15 mW 658 nm LPL, with radiant energy density of 3 J/cm2, with spot-type application in the center of the excision, during 3 (three), 7 (seven), 14 (fourteen) and 21 (twenty-one) consecutive days; GP5%: treated with 5% propolis; GP10%: treated with 10% propolis; GCL (Control Laser): control rats underwent the same procedures, but with the laser device off; GCP: control rats underwent the same procedures, but treated with a solution of sterile deionized water and 15% alcohol; GLP5%: treated with LPL associated with 5% propolis; GLP10%: treated with LPL associated with 10% propolis. The animals were sacrificed and histologically processed for the quantitative analysis of fibroblasts and blood vessels by means of light microscopy. Statistical tests were applied by the mean and the standard deviation in each group, based on the program SPSS 15.0, version 2007. The results showed statistical differences (Kruskal-Wallis, p≤0.01 and p≤0.05) in LPL treatment on day 3; 5% propolis treatment on day 7; LPL + 10% propolis on days 14 and 21, when compared with the other groups. No significant statistical difference was found on days 3, 7, 14 and 21 with the LPL and 5% propolis, but, when compared with the other groups, the results were significant. In face of the results, especially on days 3 and 7, both laser and propolis contributed to a faster wound healing. / O tratamento de feridas envolve aspectos sistêmicos e locais desenvolvidos por profissionais de diferentes áreas, destacando-se o laser de baixa potência e a própolis. Objetivou-se identificar e comparar histologicamente os efeitos da aplicação do laser de baixa potência (LBP) 658 nanômetros (nm), da própolis e associação de ambas sobre lesões de pele de Rattus norvegicus albinus, induzidas cirurgicamente, por meio de estudo histológico. Utilizaram-se 140 ratos albinos, machos da linhagem WISTAR (Rattus novergicus albinus), com 16 semanas, peso 350 a 500g, provenientes do Biotério Central da Universidade José do Rosário Vellano UNIFENAS. Após a anestesia geral com uso de ketamina® (cloridrato de cetamina)/ Rompun® (cloridrato de xilazina) (0,2 mL para cada 100g de peso por animal, sendo 50% de ketamina e 50% de Rompun), os ratos foram submetidos à tricotomia no dorso (região entre as escápulas) e, posteriormente, à excisão cirúrgica circular da epiderme, com uso do punch devidamente milimetrado (0,5 cm de diâmetro). Os animais foram distribuídos em 7 grupos: GL: aplicando-se o laser de baixa potência 658 nm, 15 mW de potência, com densidade de energia radiante de 3 J/cm2, com aplicação do tipo pontual, no centro da excisão, durante 03 (três), 07 (sete), 14 (catorze) e 21 (vinte e um) dias consecutivos; GP5%: os ratos foram submetidos à aplicação da própolis a 5%; GP10%: os ratos foram submetidos à aplicação da própolis a 10%; GCL (Controle Laser): os ratos controle foram submetidos aos mesmos procedimentos, porém com o aparelho de laser desligado; GCP: os ratos controle foram submetidos aos mesmos procedimentos, porém com o uso de solução composta por água deionizada estéril e álcool a 15%; GLP5%: os ratos foram submetidos à aplicação de laser de baixa potência associado a própolis 5%; GLP10%: os ratos foram submetidos à aplicação de laser de baixa potência associado a própolis 10% . Após o sacrifício dos animais, procedeu-se à análise histológica para análise quantitativa do número de fibroblastos e vasos sanguíneos, por meio de microscopia de luz. Processaram-se os resultados e, por meio da média e desvio padrão em cada grupo, foram aplicados os testes estatísticos, alicerçados pelo programa SPSS 15.0, versão 2007. Os resultados evidenciaram que aos 3 dias com tratamento laser; aos 7 dias com tratamento própolis a 5%; aos 14 e 21 dias com tratamento associado de laser e própolis a 10% diferiram estatisticamente (Kruskal-Wallis, p≤0,01 e p≤0,05) quando comparados aos demais grupos. Não houve diferença estatisticamente significante aos 3, 7, 14 e 21 dias com tratamento associado de laser e própolis a 5%, porém, ao comparar os grupos associados com demais grupos, seus resultados foram significativos. Diante dos resultados, principalmente aos 3 e 7 dias, observou-se que tanto o laser quanto a própolis contribuíram para um reparo mais rápido da lesão.

The development of tissue engineered blood vessel mimics for the testing of intravascular devices in vitro has been established in the Cal Poly tissue engineering lab. Due to the prevalence of cardiovascular disease in diabetic patients and minimal accessible studies regarding the interactions between diabetes and intravascular devices used to treat vascular disease, there is a need for the development of diabetic models that more accurately represents diabetic processes occurring in the blood vessels, primarily endothelial dysfunction. This thesis aimed to create a diabetic blood vessel mimic by implementing a high glucose environment for culturing human endothelial cells from healthy umbilical veins (HUVECs) and from diabetic coronary arteries (DHCAECs). The characterization of these BVMs was achieved using immunofluorescence, scanning electron microscopy (SEM), and qPCR gene expression analysis. From this study, it was determined that HUVECs and DHCAECs are robust enough to be cultured in a high glucose environment – analogous to hyperglycemia – and these cells exhibited different characteristics when evaluated under microscopy and qPCR gene expression. The immunofluorescence and SEM imaging showed presence of cells within each blood vessel mimic. The qPCR gene expression analysis demonstrated that mRNA expression of endothelial nitric oxide synthase (eNOS), platelet endothelial cell adhesion molecule (PECAM), and receptor for advanced glycation end products (RAGE) differs between HUVECs and DHCAECs, as well as between cells cultured in v normal and elevated glucose concentrations. These differences in gene regulation indicate the potential of the diabetic BVM to more accurately represent the endothelial response to diabetes and to the implementation of intravascular devices in the future. It was determined that culturing DHCAECs in a high glucose cell media for use in blood vessel mimics results in a model that differs considerably from HUVECs grown in normal glucose media. It was also determined that there was a difference between DHCAECs cultured in high glucose media and normal glucose media, as well as HUVECs cultured in high glucose media and normal glucose media. This study aided the development of a diabetic BVM; however, there are still improvements to be made, namely the inclusion of vascular smooth muscle cells in the model and improving the confluency of the BVM.

No description available.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / The passive properties of the venous wall are important in the development of venous pathology. Increase in venous pressure due to retrograde flow (reflux) and obstruction of venous flow by intrinsic and extrinsic means are the two possible mechanisms for venous hypertension. Reflux is the prevailing theory in the etiology of venous insufficiency. The objective of this thesis is to quantify the passive biomechanical response and structural remodeling of veins subjected to chronic venous reflux and hypertension. To investigate the effects of venous reflux on venous mechanics, the tricuspid valve was injured chronically in canines by disrupting the chordae tendineae. The conventional inflation-extension protocol in conjunction with intravascular ultrasound (IVUS) was utilized to investigate the passive biomechanical response of both control common iliac veins (from 9 dogs) and common iliac veins subjected to chronic venous reflux and hypertension (from 9 dogs). The change in thickness and constituent composition as a result of chronic venous reflux and hypertension was quantified using multiphoton microscopy (MPM) and histological evaluation. Biomechanical results indicate that the veins stiffened and became less compliant when exposed to eight weeks of chronic venous reflux and hypertension. The mechanical stiffening was found to be a result of a significant increase in wall thickness (p < 0.05) and a significant increase in the collagen to elastin ratio (p < 0.05). After eight weeks of chronic reflux, the circumferential Cauchy stress significantly reduced (p < 0.05) due to wall thickening, but was not restored to control levels. This provided a useful model for development and further analysis of chronic venous insufficiency and assessment of possible intervention strategies.

Indiana University-Purdue University Indianapolis (IUPUI) / Peripheral arterial disease is caused by plaque buildup in the peripheral arteries. Standard treatments are available when the blockage is proximal and focal, however when distal and diffuse the same type of the treatment options are not beneficial due to the diseased locations. Restoration of blood flow and further salvaging of the limb in these patients can occur in a retrograde manner through the venous system, called retroperfusion or arteriovenous reversal. Retroperfusion has been explored over the last century, where early side to side artery to venous connections had issues with valve competency prohibiting distal flows, edema buildup, and heart failure. However, more recent clinical studies create a bypass to a foot vein to ensure distal flows, and though the results have been promising, it requires a lengthy invasive procedure. It is our belief that the concerns of both retroperfusion approaches can be overcome in a minimally invasive/catheter based approach in which the catheter is engineered to a specific resistance that avoids edema and the perfusion location allows for valves to be passable and flow to reach distally. In this approach, the pressure flow relations were characterized in the retroperfused venous system in ex-vivo canine legs to locate the optimal perfusion location followed by in-vivo validation of canines. Six canines were acutely injured for 1-3 hours by surgical ligation of the terminal aorta and both external iliac arteries. Retroperfusion was successfully performed on five of the dogs at the venous popliteal bifurcation for approximately one hour, where flow rates at peak pressures reached near half of forward flow (37±3 vs. 84±27ml/min) and from which the slope of the P/F curves displayed a retro venous vasculature resistance that was used to calculate the optimal catheter resistance. To assess differences in regional perfusion, microspheres were passed during retroperfusion and compared to baseline microspheres passed arterially prior to occlusion in which the ratio of retroperfusion and forward perfusion levels were near the ratio of reversed and forward venous flow (0.44) throughout the limb. Decreases in critical metabolites during injury trended towards normal levels post-retroperfusion. By identifying the popliteal bifurication as a perfusion site to restore blood flow in the entirety of the distal ischemic limb, showing reversal of injury, and knowing what catheter resistances to target for further chronic studies, steps towards controlled retroperfusion and thus more efficient treatment options can be made for severe PAD patients.