Introdução: a revascularização miocárdica (RM) sem circulação extracorpórea (CEC) tem sido associada a menores complicações quando comparadas à com CEC. Objetivos: determinar os efeitos da CEC em marcadores de hemostasia, fibrinólise, inflamação e correlacionar com eventos clínicos. Método: os pacientes foram incluídos de forma prospectiva e randomizada para cirurgia de RM com (n=41) ou sem CEC (n=51). As concentrações de proteína C reativa (PCR), fibrinogênio, dímero-D e inibidor do ativador do plasminogênio tipo 1 (PAI1) foram quantificadas antes e após (1 e 24 horas) a RM. As técnicas cirúrgicas e anestésicas foram padronizadas para ambos os grupos. Eventos clínicos foram avaliados durante a hospitalização inicial e após 1 ano de seguimento. Resultados: as concentrações de PAI1 e dímeros-d foram maiores quando comparados os valores pré-operatórios com os de 1 e 24 h, após a RM em ambos os grupos, porém as concentrações de PAI1 aumentadas estenderam-se por 24 h após a RM com CEC (p<0,01). A concentração de PCR teve um aumento de pequena magnitude imediatamente após a cirurgia em ambos os grupos e aumentou de modo similar 24h após a RM (p<0,01). A RM com CEC foi associada com maior perda sanguínea durante a cirurgia e mais sangramento pós-operatório (p<0,01). A incidência de todas as outras complicações foi similar nos dois grupos. Conclusão: a RM com CEC apresentou evidências bioquímicas de um estado pró-trombótico precoce após a cirurgia, porém, sem evidências no aumento no número de eventos trombóticos. O estado pró-trombótico pode ser consequência do circuito extracorpóreo, resposta compensatória ao sangramento, ou a ambos em pacientes submetidos à cirurgia com CEC. / Objective: To delineate the effects of extracorporeal bypass on biomarkers of hemostasis, fibrinolysis, and inflammation and clinical sequelae. Methods: Patients were assigned prospectively and randomly to either on-pump (n=41) or off-pump (n=51) coronary bypass surgery. The concentrations of C-reactive protein (CRP), fibrinogen, D-dimer, and plasminogen activator inhibitor type 1 (PAI-1) in blood were quantified before and after (1 hour and 24 hours) surgery. Similar surgical and anesthetic procedures were used for both groups. Clinical events were assessed during initial hospitalization and at the end of 1 year. Results: The concentrations of PAI-1 and d-dimer were greater compared with preoperative values 1 hour and 24 hours after surgery in both groups, but their concentrations increased to a greater extent 24 hours after surgery in the on-pump group (p<0.01). The concentration of CRP did not change appreciably immediately after surgery in either group but increased in a parallel fashion 24 hours after either on-pump or off-pump surgery (p<0.01). Bypass surgery in the on-pump group was associated with greater blood loss during surgery and more bleeding after surgery (p0.01). The incidence of all other complications was similar in the 2 groups. Conclusion: On-pump surgery was associated with biochemical evidence of a pro-thrombotic state early after surgery but no greater incidence of thrombotic events. The pro-thrombotic state may have been a consequence of extracorporeal bypass, compensation in response to more bleeding, or both in patients undergoing on-pump surgery.

Introduction: Cardiovascular surgery is a relatively young but progressively evolving field in medicine. More specifically, in the past decades, cardiac surgery achieved significant advances in understanding the causes, progression and treatments of ischemic heart disease (IHD). The IHD is the most common coronary disease, and it ranks first in morbidity and mortality in the developed world. It justifies the need for significant fundamental research as well as its study in clinical practice. It now includes specialized cardiovascular centres with the complex specialized treatments. A group of interventional cardiologists capable of performing routine examinations of the coronary veins using selective angiography has been established. They can eventually also perform percutaneous coronary interventions with direct stent implants. Thus the advances have been made in comprehensive indication of the patients towards their optimal treatments under the regime of a cardio-team. Such team comprises of a cardio-surgeon, interventional cardiologist, echocardiography specialist and the attending physician who is usually the cardiologist. The IHD treatments involve preventive cardiology with the regime measures and checks, pharmacotherapy, interventional cardiology and cardiac surgery to spa treatment and...

Introduction: Cardiovascular surgery is a relatively young but progressively evolving field in medicine. More specifically, in the past decades, cardiac surgery achieved significant advances in understanding the causes, progression and treatments of ischemic heart disease (IHD). The IHD is the most common coronary disease, and it ranks first in morbidity and mortality in the developed world. It justifies the need for significant fundamental research as well as its study in clinical practice. It now includes specialized cardiovascular centres with the complex specialized treatments. A group of interventional cardiologists capable of performing routine examinations of the coronary veins using selective angiography has been established. They can eventually also perform percutaneous coronary interventions with direct stent implants. Thus the advances have been made in comprehensive indication of the patients towards their optimal treatments under the regime of a cardio-team. Such team comprises of a cardio-surgeon, interventional cardiologist, echocardiography specialist and the attending physician who is usually the cardiologist. The IHD treatments involve preventive cardiology with the regime measures and checks, pharmacotherapy, interventional cardiology and cardiac surgery to spa treatment and...

Synthetic vascular grafts are useful to bypass diseased arteries. The long-term failure of synthetic grafts is primarily due to intimal hyperplasia at the anastomotic sites. The accelerated intimal hyperplasia may stem from a compliance mismatch between the host artery and the graft since commercially available synthetic conduits are much stiffer than an artery. The objective of this thesis is to design a method for fabricating a vascular graft that mechanically matches the patients native artery over the expected physiologic range of pressures. The creation of an optimized mechanical graft will hopefully lead to an improvement in patency rates. The mechanical equivalency between the graft and the host artery is defined locally by several criteria including the diameter upon inflation, the elasticity at mean pressure, and axial force. A single parameter mathematical for a thin-walled tube is used to describe of the final mechanical behavior of a synthetic graft. For the general problem, the objective would be to fabricate a mechanics-matching vascular graft for each host artery. Typically, fabrication parameters are set initially and the properties of the fabricated graft are measured. However, by modeling the entire fabrication process and final mechanical properties, it is possible to invert the situation and let the typical output mechanical values be used to define the fabrication parameters. The resultant fabricated graft will then be mechanically matching. As a proof-of-concept, several prototype synthetic grafts were manufactured and characterized by a single Invariant to match a canine artery. The resultant graft equaled the diameter upon inflation, the elasticity at mean pressure, and axial force of the native canine artery within 6%. An alternative to making an individual graft for each artery is also presented. A surgeon may choose the best graft from a set of pre-manufactured grafts, using a computer program algorithm for best fit using two parameters in a neighborhood. The design optimization problem was solved for both canine carotid and human coronary arteries. In conclusion, the overall process of design, fabrication and selection of a mechanics matching synthetic vascular graft is shown to be reliable and robust.

INTRODUCTION : Les greffons de veine saphène interne (GVS) sont encore régulièrement utilisés comme conduits en chirurgie de pontage aorto-coronarien (PAC). Les dommages subis par les segments de veine saphène pendant le prélèvement et le stockage favorisent une dysfonction endothéliale qui se manifeste par une diminution de la production d'oxyde nitrique et/ou par une augmentation du niveau de stress oxydant pouvant entraîner une défaillance du greffon veineux se traduisant par une occlusion. La solution saline héparinée est la solution de préservation de référence malgré plusieurs études démontrant ses effets néfastes sur les GVS. GALA est une solution de préservation de greffons autologues vasculaires spécialement développée pour préserver l'intégrité structurale et fonctionnelle de la couche endothéliale des greffons utilisés en chirurgie de pontages aorto-coronariens. OBJECTIF : Comparer la préservation de l'intégrité des fonctions endothéliales des greffons de veine saphène après le stockage dans la solution GALA versus dans la solution saline héparinée dans le cadre d’une étude contrôlée et randomisée en étudiant la réactivité vasculaire en chambres d’organes. RÉSULTATS : Les segments de GVS d'un total de quinze patients ont été obtenus et divisés en anneaux de 3 mm de largeur. Il n'y avait pas de différences significatives dans les niveaux de contraction en réponse au chlorure de potassium, à la phényléphrine, ni dans les concentrations de phényléphrine nécessaires pour atteindre le niveau de contraction cible entre les anneaux du groupe GALA versus le groupe de saline héparinée. Les courbes dose-réponse du groupe solution GALA ont démontré une amélioration significative des relaxations dépendantes de l'endothélium par rapport au groupe solution saline héparinée. Les contractions et relaxations indépendantes de l'endothélium induites respectivement par la phényléphrine et le nitroprussiate de sodium étaient similaires dans les anneaux de GVS des deux groupes. CONCLUSION : L’utilisation intra-opératoire d'une solution développée spécifiquement pour la préservation de l’intégrité endothéliales présente un potentiel d’avantages cliniques chez les patients qui subissent une chirurgie de PAC. Les observations précédentes suggèrent que la solution GALA pourrait réduire la dysfonction endothéliale associée à la défaillance des greffons veineux et incite des évaluations à long terme plus approfondies dans le cadre d’essais cliniques. / INTRODUCTION: Saphenous vein grafts (SVGs) are still commonly used as conduits for coronary artery bypass grafting (CABG). Injury to SVGs during harvesting and storage promotes endothelial dysfunction, which is attributed to a decrease in production of nitric oxide and/or increased level of oxidative stress that can lead to vein graft failure (VGF). Heparinized saline is still the standard of care intraoperative preservation solution despite several studies demonstrating its detrimental effects on SVGs. GALA is an innovative one-time intraoperative graft storage solution developed to preserve endothelial integrity. OBJECTIVE: To investigate, in a randomized controlled study, endothelial functional integrity of saphenous vein grafts following storage in GALA vs heparinized saline using ex vivo vascular reactivity studies in organ chamber experiments. RESULTS: Segments of saphenous vein grafts from a total of fifteen patients were obtained and divided into 3 mm wide rings for evaluation. There were no significant differences in the levels of contraction in response to potassium chloride and to phenylephrine between groups, nor in the concentrations of phenylephrine needed to achieve the target level of contraction in saphenous vein graft rings. Concentration-response curves of the GALA group demonstrated a significant improvement in endothelium-dependent relaxations compared to the heparinized saline group. Endothelium-independent contractions and relaxations induced by phenylephrine and sodium nitroprusside, respectively, were not altered in saphenous vein graft rings from both groups. CONCLUSIONS: Intraoperative application of a solution developed for graft preservation demonstrated a potential benefit to protect endothelial and vascular functional integrity in saphenous vein grafts of patients undergoing CABG. These data suggest that the GALA solution may reduce endothelial dysfunction associated with vein graft failure and warrant further long-term evaluation in clinical trials.