<p>The obligate intracellular bacterium <i>Chlamydia pneumoniae (Cp</i>), a common human pathogen, has been associated with atherosclerotic cardiovascular disease. The aetiology of non-rheumatic aortic valve sclerosis has, however, not been clarified. In two prospective studies of 42 and 46 patients undergoing surgical valve replacement because of aortic valve stenosis, the presence of <i>Cp </i>DNA could be demonstrated by polymerase chain reaction (PCR) in 49% and 35% of the sclerotic valves as compared to 9 % and 0%, respectively, of valves from forensic control cases with no heart valve disease. Some inflammatory and infectious diseases are associated with trace element changes. Eleven of 15 trace elements showed changed concentrations in sclerotic valve tissue compared to control valves in support of an active process in the sclerotic valves. Notable was an increased iron concentration in the patients´ valves suggesting a possible link to <i>Cp</i>. Furthermore, a disturbed trace element balance existed in the patients´ sera, the pattern of which was compatible with ongoing infection. In a prospective study of 38 patients operated on for thoracic aortic aneurysm or dissection, <i>Cp</i> DNA <i>w</i>as detected byPCR in 12 % of the aneurysms and the result was confirmed byelectron microscopy(EM<i>).</i> In none of the dissection patients could <i>Cp </i>be demonstratedin the removed tissues. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for doxycycline and azithromycin increased with longer <i>Cp </i>preincubation times when tested in vitro<i>.</i> EMwas performed to visualise the inactivation at a cellular level.Thus, the results demonstrate <i>Cp </i>in the tissues in non-rheumatic aortic valve sclerosis and in thoracic aortic aneurysm but not in aortic dissection.</p>

<p>The mortality of thoracic aortic diseases (mainly aneurysms and dissections) is high, even with surgical treatment. Epidemiology and long-term outcomes are incompletely investigated. Stroke is a major complication contributing to mortality, morbidity, and possibly to reduced quality of life. </p><p><i>Study I</i> Increasing incidence of thoracic aortic diseases 1987 – 2002 was demonstrated (n=14229). Annual number of operations increased eight-fold. Overall long-time survival was 92%, 77%, and 57% at 1, 5, and 10 years. Risk of operative and long-term mortality was reduced across time.</p><p><i>Study II</i> 2634 patients operated on the proximal thoracic aorta (Swedish Heart Surgery register) were examined. Aortic valve replacement, coronary revascularization, emergency operation, and age were independently associated with surgical death. Long-term mortality was similar for aneurysms and dissections. Operative mortality was reduced (13.7% vs 7.2%) for aneurysms but remained unchanged (22.3% vs 22.4%) for dissections across time.</p><p><i>Study III</i> 65 patients underwent selective antegrade cerebral perfusion (SACP) uni- or bilaterally. Stroke was significantly more common after unilateral SACP (29% vs 8%, p=0.045), confirmed by propensity score-matched analysis. Subclavian artery cannulation with Seldinger-technique entailed vascular complication in one case (1.5%).</p><p><i>Study IV</i> Near-infrared spectroscopy (NIRS) was used to monitor cerebral tissue saturation (rSO2) during SACP in 46 patients. Lower rSO2 were encountered (1) in patients suffering a stroke (2) with unilateral SACP, and (3) in the affected hemisphere of stroke victims. A decrease of rSO2 by 14 – 21% from baseline increased the risk of stroke significantly.</p><p><i>Study V</i> Quality of life (QoL) in 76 survivors of thoracic aortic surgery was examined with the SF-36 health questionnaire. Except for pain, QoL was reduced in all dimensions. QoL was not affected by acuity of operation. Tendencies of lower QoL after descending aortic operations, after major complications, and with persistent dysfunction were non-significant.</p>

The obligate intracellular bacterium Chlamydia pneumoniae (Cp), a common human pathogen, has been associated with atherosclerotic cardiovascular disease. The aetiology of non-rheumatic aortic valve sclerosis has, however, not been clarified. In two prospective studies of 42 and 46 patients undergoing surgical valve replacement because of aortic valve stenosis, the presence of Cp DNA could be demonstrated by polymerase chain reaction (PCR) in 49% and 35% of the sclerotic valves as compared to 9 % and 0%, respectively, of valves from forensic control cases with no heart valve disease. Some inflammatory and infectious diseases are associated with trace element changes. Eleven of 15 trace elements showed changed concentrations in sclerotic valve tissue compared to control valves in support of an active process in the sclerotic valves. Notable was an increased iron concentration in the patients´ valves suggesting a possible link to Cp. Furthermore, a disturbed trace element balance existed in the patients´ sera, the pattern of which was compatible with ongoing infection. In a prospective study of 38 patients operated on for thoracic aortic aneurysm or dissection, Cp DNA was detected byPCR in 12 % of the aneurysms and the result was confirmed byelectron microscopy(EM). In none of the dissection patients could Cp be demonstratedin the removed tissues. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for doxycycline and azithromycin increased with longer Cp preincubation times when tested in vitro. EMwas performed to visualise the inactivation at a cellular level.Thus, the results demonstrate Cp in the tissues in non-rheumatic aortic valve sclerosis and in thoracic aortic aneurysm but not in aortic dissection.

Chronic graft dysfunction (CGD) is an important post-transplant complication. CGD can be considered as an impaired repair process, which ultimately leads to the loss of graft function.To study non-immunological factors contributing to the development of CGD in kidney grafts we used in vitro and in vivo models, and clinical studies. We studied the actions of hyperlipidemia in vitro. LDL induced increased expression of TGF-β1 and TGF-β receptors type I and type II. Smad2 phosphorylation could be induced by conditioned medium from mesangial cells incubated with LDL. The effects of Fluvastatin and AT1 receptor blocker Candesartan cilexetil on aortic graft arteriosclerosis in the rat were evaluated. Fluvastatin neither alone nor in combination with Cyclosporine A affected allograft remodelling, but reduced neointima formation in isografts. Candesartan cilexetil treatment reduced graft arteriosclerosis. The effect is explained by the reduction of TGF-β1 expression. We investigated the effects of Carvedilol in patients with CGD. Carvedilol failed to alter the CGD progression despite the efficient control of blood pressure, and a beneficial effect on lipid pattern and oxidation. Close control of CyA blood levels is recommended due to interaction between CyA and Carvedilol. Measurement of Ab-oxLDL in kidney graft recipients demonstrated that these patients had lower Ab-oxLDL levels as compared with the control group. Decreased Ab-oxLDL levels were associated with graft loss due to acute rejection and with ischemic heart disease. In this thesis we have addressed several important complex issues, which are interconnected: (1) development of chronic graft dysfunction (2) lipoproteins and their role in inducing pathological conditions like atherosclerosis and graft damage, (3) oxidation, (4) TGF-β and its' role in different pathological conditions, including renal and vascular damage.

Aortic aneurysm and dissections are potentially life threatening conditions. The advent of endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR) has reduced perioperative mortality and morbidity and are now established therapy methods for treatment of aortic disease. Adequate pre- and intraoperative imaging is important for optimal results in endovascular procedures. However, the standard use of CT and angiography may not always be sufficient to provide necessary information required for treatment, and complementary techniques are warranted in selected cases. TEVAR in acute complicated type B aortic dissections is proven effective in several reports, but long-term clinical outcome and aortic remodelling are still not fully evaluated. Intravascular phased array imaging (IPAI) was used in patients undergoing EVAR and TEVAR for aortic aneurysm and dissection. The combined information from IPAI and fluoroscopy allowed exact positioning of the stent graft. The colour Doppler function facilitated detection of blood-flow in relevant arteries during and after the procedures, and it also facilitated control of ceased flow in excluded false lumens or aneurysms. Clinical early and long-term results after TEVAR for acute complicated type B aortic dissection were investigated in all patients treated between 1999 and 2009 at UppsalaUniversityHospital. Results were favourable regarding survival and permanent neurological complications. Long-term follow-up of aortic morphological changes in the same patient group showed overall significant reduction of aortic and false lumen diameters, and an increase of true lumen diameter. Total thrombosis of the false lumen occured more often in patients with DeBakey IIIa aortic dissection, than in IIIb. In conclusion, IPAI may be a complementary tool to traditional imaging modalities in EVAR and TEVAR in selected cases. Long-term clinical outcome is excellent with favourable aortic remodeling after TEVAR in patients with acute complicated type B aortic dissection.

The mortality of thoracic aortic diseases (mainly aneurysms and dissections) is high, even with surgical treatment. Epidemiology and long-term outcomes are incompletely investigated. Stroke is a major complication contributing to mortality, morbidity, and possibly to reduced quality of life. Study I Increasing incidence of thoracic aortic diseases 1987 – 2002 was demonstrated (n=14229). Annual number of operations increased eight-fold. Overall long-time survival was 92%, 77%, and 57% at 1, 5, and 10 years. Risk of operative and long-term mortality was reduced across time. Study II 2634 patients operated on the proximal thoracic aorta (Swedish Heart Surgery register) were examined. Aortic valve replacement, coronary revascularization, emergency operation, and age were independently associated with surgical death. Long-term mortality was similar for aneurysms and dissections. Operative mortality was reduced (13.7% vs 7.2%) for aneurysms but remained unchanged (22.3% vs 22.4%) for dissections across time. Study III 65 patients underwent selective antegrade cerebral perfusion (SACP) uni- or bilaterally. Stroke was significantly more common after unilateral SACP (29% vs 8%, p=0.045), confirmed by propensity score-matched analysis. Subclavian artery cannulation with Seldinger-technique entailed vascular complication in one case (1.5%). Study IV Near-infrared spectroscopy (NIRS) was used to monitor cerebral tissue saturation (rSO2) during SACP in 46 patients. Lower rSO2 were encountered (1) in patients suffering a stroke (2) with unilateral SACP, and (3) in the affected hemisphere of stroke victims. A decrease of rSO2 by 14 – 21% from baseline increased the risk of stroke significantly. Study V Quality of life (QoL) in 76 survivors of thoracic aortic surgery was examined with the SF-36 health questionnaire. Except for pain, QoL was reduced in all dimensions. QoL was not affected by acuity of operation. Tendencies of lower QoL after descending aortic operations, after major complications, and with persistent dysfunction were non-significant.

Hypertension is the number one cause of death worldwide. Low-grade inflammation has been identified as one of the mechanisms contributing to blood pressure elevation and remodeling of the vasculature in hypertension. Mechanisms involved in vascular inflammation and hypertension remain elusive. Vasoactive peptides such as endothelin-1 (ET-1) and angiotensin II (Ang II), oxidative stress and infiltration of immune cells are increased in cardiovascular tissues of hypertensive individuals. Since the vasculature is a major regulator of blood pressure levels, the hypothesis has been proposed that vascular inflammatory responses contribute to development of hypertension. / Objectives of this thesis were 1) to investigate the role of T cells in development of vascular inflammation observed in genetically hypertensive rats, 2) to identify vascular sources of reactive oxygen species production in mineralocorticoid-induced hypertension and 3) to study the effect of peroxisome proliferator-activated receptor (PPAR)-gamma activators on vascular pro-inflammatory signaling pathways in Ang II-induced hypertension. / The first study that is part of this thesis shows that the transfer of chromosome 2 from normotensive to hypertensive rats reduces plasma levels of pro-inflammatory cytokines, expression of adhesion molecules and infiltration of T cells in aorta as well as resulting in lower blood pressure levels. These effects are accompanied by increased regulatory T cell mediators. We discovered that regulatory T cells are regulated by chromosome 2 and may be responsible for reducing inflammatory responses in hypertensive rats. / The second study of this thesis demonstrates in DOCA-salt hypertensive rats that superoxide (&middot;O2-) production originates in part from xanthine oxidase activity induced by the ET-1 system and from mitochondrial sources, particularly complex II of the respiratory chain. We thus have uncovered two sources of reactive oxygen species (ROS) that can stimulate inflammatory responses in hypertension, since vascular &middot;O 2- production in this model was shown to induce vascular inflammation. / The third study of the thesis shows that activators of PPAR-gamma reduce blood pressure levels and signaling pathways including Akt/PKB, SHIP2, ERK1/2, 4E-BP1 in aorta and resistance arteries in Ang II-induced hypertension. PPARy acts as an anti-inflammatory transcription factor, and the present study suggests that Ang II down-regulates PPAR-gamma activity to exert its pro-inflammatory effects. / In conclusion, by targeting inflammatory mediators, it may be possible to reduce blood pressure levels in hypertensive animals. This suggests that inflammatory responses may play a crucial role in development of high blood pressure.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-08-03T19:10:55Z No. of bitstreams: 1 TeseADSL.pdf: 24405858 bytes, checksum: dafb27a193250527d419e7d787a23a21 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-08T17:45:21Z (GMT) No. of bitstreams: 1 TeseADSL.pdf: 24405858 bytes, checksum: dafb27a193250527d419e7d787a23a21 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-08T17:45:29Z (GMT) No. of bitstreams: 1 TeseADSL.pdf: 24405858 bytes, checksum: dafb27a193250527d419e7d787a23a21 (MD5) / Made available in DSpace on 2017-08-08T17:50:08Z (GMT). No. of bitstreams: 1 TeseADSL.pdf: 24405858 bytes, checksum: dafb27a193250527d419e7d787a23a21 (MD5) Previous issue date: 2017-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Introduction: Hypertension is an important risk factor for menopausal cardiovascular disease. Resistance training (RT) when associated with the caloric restriction diet (CR) has been shown to have important effects on blood pressure and the aortic artery, minimizing complications due to menopause, such as hypertension. Aim: In this study, we investigated the effects of Ovariectomy and the Resistance Training, Caloric Restriction, and the association of both intervention in systolic blood pressure, matrix metaproteinase-2 activity, aortic vascular reactivity and morphological alterations in ovariectomized Holtzman rats. Material and methods: Fifty female Holtzman rats were subjected to ovariectomy and Sham surgery and distributed into: Sham-sedentary; Ovariectomized-sedentary; Ovariectomized- Resistance Training; Ovariectomized-Caloric Restriction; and Ovariectomized-Resistance Training and Caloric Restriction groups. Resistance Training and 30% Caloric Restriction protocols were performed by 13-weeks. Systolic blood pressure, acetylcholine, and sodium nitroprusside induced relaxation of aortic rings; the hematoxylin-eosin stain used to highlight the aortas wall cross-sectional area and the matrix metaproteinase-2 activity, insulin tolerance test and aorta vessel remodeling were analyzed. Results: We observed that, Ovariectomy increased systolic blood pressure, decreased potency in dependent and independent endothelium relaxation and matrix metaproteinase-2 activity, promoted insulin resistance and aorta vessel remodeling in cross-sectional area, media to lumen ratio, collagen content and alter structure and elastic fibers of the vessel. However, the association of exercise and diet prevent the increase systolic blood pressure, improved the relaxation potency in dependent and independent endothelium relaxation, elevated the matrix metaproteinase-2 activity, increased the aorta cross-sectional area, media to lumen ratio, decreased collagen content and alter elastic fibers in aorta vessel wall. Conclusion: Our study reveled that the association of resistance training and caloric restriction can prevent the hypertensive condition, improve vascular function, activate matrix metaproteinase-2, and produce a beneficial hypertrophic remodeling with increased vascular compliance in ovariectomy in Holtzman rats. / Introdução: A hipertensão é um importante fator de risco para doenças cardiovasculares na menopausa. O treinamento resistido (TR) quando associado à dieta de restrição calórica (RC) têm demonstrado importantes efeitos sobre a pressão arterial e a artéria aorta, minimizando complicações decorrentes da menopausa, como a hipertensão arterial. Objetivo: O presente trabalho tem como objetivo investigar os efeitos da ovariectomia e das intervenções de TR, RC e da associação de ambos (TR+RC) sobre a pressão arterial sistólica, reatividade vascular aórtica, resposta insulínica, atividade da metaloproteinase de matriz 2 e alterações morfológicas em ratas Holtzman. Materiais e métodos: Cinquenta ratas Holtzman foram submetidas à cirurgia de ovariectomia e Sham; e distribuídas nos seguintes grupos (n=10): Sham-sedentária, Ovariectomizada-sedentária, treinamento resistido ovariectomizada, restrição calórica ovariectomizada e treinamento resistido associada à restrição calórica ovariectomizada. Os protocolos de TR e 30% de RC foram realizados por 13 semanas. A pressão arterial sistólica, teste de tolerância à insulina, reatividade vascular em anéis aórticos, atividade da metaloproteinase de matriz 2, análises morfológicas utilizando coloração de Hematoxilina e Eosina, Tricrômio de Masson e Pricrosírius-red foram realizadas. Resultados: Observamos que a ovariectomia aumentou a pressão arterial sistólica, promoveu resistência à insulina, diminuiu a potência do relaxamento dependente e independente do endotélio e atividade da metaloproteinase de matriz 2, além de promover o remodelamento do vaso aórtico sobre a área da secção transversal, relação túnica média/lúmen, alterando o conteúdo de colágeno e fibras elásticas da artéria aorta. No entanto, a associação entre exercício e dieta e ambos separados, preveniram o aumento da pressão arterial sistólica, melhoraram a potência do relaxamento dependente e independente do endotélio, promoveram ativação da metaloproteinase de matriz 2, aumento da área da secção transversal da aorta, da relação túnica média/lúmen, além de promover a diminuição do conteúdo de colágeno e alteração das fibras elásticas na parede do vaso aórtico. Conclusão: O presente estudo mostrou que os efeitos do TR e RC, associados ou realizados separadamente, foram eficientes para melhorar os parâmetros clínicos e moleculares, prevenindo o surgimento da condição de hipertensão, melhorando a função vascular, a resposta insulínica, a atividade da metaloproteinase de matriz 2 e o remodelamento da aorta com aumento da complacência vascular, na condição de hipertensão induzida pela ovariectomia em ratas Holtzman. / FAPESP: 2012/21087-4

Galectina-1 (Gal-1) pertence à família de lectinas que reconhecem -galactosídeos e pode ser expressa em vários tipos celulares, incluindo as células endoteliais e músculo liso. Esta lectina endógena possui propriedades imunomodulatórias e antiinflamatórias, dependentes de processos celulares, essenciais incluindo ativação, diferenciação, sobrevivência, fagocitose e adesão celular. Os eventos iniciais da lesão vascular são pouco conhecidos e, na literatura, são escassos os dados sobre a participação da Gal-1 nesses eventos. Portanto, neste trabalho, pretendeu-se avaliar a participação dessa lectina nos eventos iniciais da lesão vascular por hiperhomocisteinemia moderada induzida em camundongos. A dose padrão de 0,4g/Kg/dia de homocisteína-tiolactona foi administrada oralmente a camundongos selvagens (Gal-1+/+) e destituídos do gene da Gal-1 (Gal-1-/-), por diferentes tempos, causando uma elevação da concentração plasmática de homocisteína total, Este fato provocou alterações na reatividade vascular de contração na artéria aorta e de rolamento e adesão de leucócitos em vênulas mesentéricas. Foi detectada a presença da Gal-1 nas aortas de animais Gal-1+/+ em todos tempos de tratamento e no controle, observando, porém, um aumento dela no grupo tratados por 15 dias e, mais expressa em 24 horas (expressão protéica por Western blot e imunofluorescência e, gênica por Real Time PCR). Neste tempo, houve maiores alterações metabólicas significativas como triglicérides, LDL, colesterol total, glicose e de homocisteína. A análise da expressão das óxido nítrico sintases revelou não haver alterações para NOS induzida (iNOS) entre os grupos de animais Gal-1+/+ controle e tratados, nem mesmo em relação aos animais controles Gal-1-/-. Entretanto, o tratamento modulou a expressão da NOS endotelial (eNOS) nos animais Gal-1+/+, havendo uma redução da proteína para os tempos de 48 horas e 7dias (expressão protéica por imunohistoquímica - peroxidade e, gênica por RT-PCR). O tratamento não alterou a concentração plasmática de óxido nítrico (NO) em camundongos Gal-1+/+, mas foi detectada redução dos valores basais para animais Gal-1-/- e, uma redução com o tratamento por 15 dias. Portanto, foi verificado que a expressão de Gal-1 foi aumentada com o tratamento de Hcy-Taq nos tempos de 24 horas e 15 dias, onde se observam significativas e maiores alterações biológicas dos parâmetros de lesão vascular induzida pela hiperhomocisteinemia moderada analisadas: reatividade vascular, rolamento e adesão de leucócitos em vênulas mesentéricas, concentração de homocisteína plasmática, perfil lipídico e expressão da óxido nítrico sintase endotelial. / Galectin-1 (Gal-1) belongs to the lectin family of -galactosides-binding proteins and can be expressed by several cell types, including endothelial cells and vascular smooth cells. This endogenous lectin has immunological and anti-inflammatory properties dependent of essential cellular processes, including activation, differentiation, survival, phagocytosis and cell adhesion. There are few and inconclusive studies about the engagement of Gal-1 in vascular injury initial processes. Thus, this work was conducted to evaluate the engagement of Gal-1 in hyperhomocysteinemia-induced vascular injury. Wild type (Gal-1+/+) and Gal-1-knockout (Gal-1-/-) mice were fed with 0,4g/Kg/day with thiolactone-homocysteine (D,L Hcy-T) for different times, provoking increased plasmatic total homocysteine levels. That has indicated alterations in aortic vasomotor responses and mesenteric venial leukocyte rolling and adhesion. Gal-1 was detected in aortic frozen section of Gal-1+/+ mice for all times of treatment with D,L Hcy-T, but more detected for aorta of 15 days treated animal group and, more expressed, for 24 hours ones (protein expression by Western blot and immunofluorescence and, genetic by Real Time PCR). Besides, at 24 hours of treatment, many metabolic alterations were observed: increased LDL, triglycerides, cholesterol, glucose and homocysteine levels. Expressions for nitric oxide sintases (NOS) showed no alteration for inducible NOS (iNOS) for Gal-1+/+ mice (treated or not), even for Gal-1-/- untreat mice. However, the treatment was able to modulate endothelial NOS (eNOS) decreasing the expression at 48 hours and 7 days treated animals group (protein expression by imunoperoxidase and, genetic by RT-PCR). Gal-1-/- mice have less circulating constitutive nitric oxide (NO) than Gal-1+/+ ones, and, the treatment has reduced these levels only for Gal-1-/- 15 days treated mice but not for Gal-1+/+ ones . This work, therefore, has shown that Gal-1 is always expressed by aortas. However, increased expression of Gal-1 at 24 hours and 15 days of treatment has been often correlated to biological alterations in the in hyperhomocysteinemia-induced vascular injury: aortic vasomotor responses, leukocyte rolling and adhesion in mesenteric venues, plasmatic homocysteine, lipid metabolites and NOS expression.

Introdução: A correção do aneurisma pela técnica endovascular ganha mais espaço com o aprimoramento do material utilizado, buscando-se um sistema ideal. Os estudos com esses dispositivos necessitam de modelos experimentais que devem apresentar características anatômicas e fisiopatológicas similares aos aneurismas em humanos. Apresentamos um novo modelo com bolsa de pericárdio bovino em suínos, com abordagem cirúrgica por via retroperitonial. Materiais e métodos: Estudo prospectivo, de coorte, avaliado pelo comitê de bioética, utilizando 11 suínos de raça Large White e do sexo feminino, com idade de 12 semanas, dividido em duas fases. A fase I consistiu na confecção do aneurisma, abordando a aorta retroperitonial com anestesia geral; na fase II, após 15 dias, realizou-se a arteriografia, eutanásia e retirada da peça para estudo anatomopatológico. Resultados: Em todos os animais, observou-se formação de trombos murais, como ocorre em aneurismas verdadeiros que comprometem de 30 a 90% da luz. À microscopia foram observadas calcificações na região do trombo em 82% dos animais. Havia infiltrado linfoplasmocitário no enxerto e região perienxerto, com fibrose em nove animais. Em três suínos havia espessamento miointimal considerável, e em oito, microcalcificações. A mortalidade foi nula, sem complicações cirúrgicas locais, isquêmicas e de ruptura. Conclusão: O modelo corresponde ao objetivo inicial de manter a aorta, seus ramos colaterais e terminais pérvios, com achados estruturais semelhantes aos de aneurismas encontrados em humanos: reação inflamatória parietal, periadvencial, trombo e calcificações da parede. As técnicas anestésica e operatória desenvolvidas foram satisfatórias e de morbimortalidade nula no período avaliado. / Background: The correction of an aneurysm using endovascular techniques has gained importance with the improvement of materials. The study of endovascular prostheses requires experimental models that reproduce anatomic and physiopathologic characteristics of human aneurysms. This study describes a new swine model that used bovine pericardium and a retroperitoneal surgical approach. Material and methods: This prospective cohort study used eleven Large White female pigs with a mean age of 12 weeks in the two study phases. In phase I, the aneurysm was produced and surgery using a retroperitoneal approach to the aorta under general anesthesia was performed; and in phase II, 15 days later, the animals underwent arteriography and were later killed, and specimens were removed for histological analysis Results: The formation of parietal thrombus, which is also found in true aneurysms that involve 30 to 90% of the lumen, was observed in all animals. Microscopic analysis showed calcifications in the area of thrombus in 82% of the animals. There was lymphoplasmocytic infiltration in the graft and adjacent area, with fibrosis in nine animals. Three pigs had substantial myointimal thickening, and eight had microcalcifications. Mortality was zero, and there were no ruptures, ischemia or surgery site. Conclusion: The aorta and its collateral and terminal branches remained healthy, and structural findings were similar to those observed in human aneurysms: wall inflammation, periadventitial thrombus and wall calcification. The anesthetic and operatory techniques were satisfactory, and there was no morbidity or mortality during the study.