Human Saphenous Vein Organ Culture Under Controlled Hemodynamic Conditions

INTRODUCTION: Saphenous vein grafting is still widely used to revascularize ischemic myocardium. The effectiveness of this procedure is limited by neointima formation and accelerated atherosclerosis, which frequently leads to graft occlusion. A better understanding of this process is important to clarify the mechanisms of vein graft disease and to aid in the formulation of strategies for prevention and/or therapeutics. OBJECTIVE: To develop an ex vivo flow system that allows for controlled hemodynamics in order to mimic arterial and venous conditions. METHODS: Human saphenous veins were cultured either under venous (flow: 5 ml/min) or arterial hemodynamic conditions (flow: 50 ml/min, pressure: 80 mmHg) for 1-, 2- and 4-day periods. Cell viability, cell density and apoptosis were compared before and after these intervals using MTT, Hoeschst 33258 stain, and TUNEL assays, respectively. RESULTS: Fresh excised tissue segments were well preserved prior to the study. Hoechst 33258 and MTT stains showed progressive losses in cell density and cell viability in veins cultured under arterial hemodynamic conditions from 1 to 4 days, while no alterations were observed in veins cultured under venous conditions. Although the cell density from 1-day cultured veins under arterial conditions was similar to that of freshly excised veins, the TUNEL assay indicated that most of these cells were undergoing apoptosis. CONCLUSION: The results observed resemble the events taking place during early in vivo arterial-vein grafting and provide evidence that an ex vivo perfusion system may be useful for the identification of new therapeutic targets that ameliorate vein graft remodeling and increase graft patency over time

Degree of risk related to procedures performed in conjunction with surgical myocardial revascularization in octogenarians

INTRODUCTION/OBJECTIVES: We determined the degree of risk produced by the association of other surgical procedures with surgical myocardial revascularization in octogenarian patients and identified the risk factors that best explain hospital mortality. METHODS: This study was an observational analytical historical cohort study involving octogenarians operated on at our institution between January 1, 2000 and January 1, 2005. We stratified the objective population as follows: Group 1 comprised octogenarians revascularized without associated procedures, and Group 2 comprised octogenarians revascularized with associated procedures. Statistical analyses included the t test for independent samples and multiple logistic regression analysis. Significance was accepted with an alpha error of 5%. RESULTS: Univariate analyses revealed the following clinical and statistically significant variables: hospital mortality (P=0.002), diabetes mellitus (P=0.017), preoperative endocarditis (P=0.001), cardiogenic shock (P=0.019), use of an intra-aortic balloon pump (P=0.026), preoperative risk score (Parsonnet), P<0.001, procedure associated with revascularization (P<0.001), medium number of affected coronary arteries (P<0.001), use of extracorporeal circulation (P<0.001), time of extracorporeal circulation (P<0.001), number of distal anastomoses (P=0.002), graft type (P<0.001), postoperative breathing support (P<0.001), stroke (P<0.001), infection (P=0.002), creatinine level (P=0.018), and quality of life score (P=0.050). DISCUSSION/CONCLUSIONS: In octogenarian patients, the need for a procedure associated with surgical myocardial revascularization produces an absolute increase in hospital mortality risk of 45%. The variables that contributed to hospital mortality were preoperative endocarditis, preoperative cardiogenic shock, the use of extracorporeal circulation, the length of time of extracorporeal circulation, postoperative creatinine level, and postoperative need for prolonged respiratory support

Hybrid CABG: an alternative for perfusion time decrease

OBJETIVO: Avaliar a possibilidade da redução do tempo de circulação extracorpórea (CEC) e das complicações relacionadas a esta variável na revascularização do miocárdio (RM), utilizando o método híbrido como alternativa. MÉTODOS: Noventa pacientes foram analisados, retrospectivamente, entre março/2000 e agosto/2006. Todos foram revascularizados com três ou mais enxertos e divididos em doisgrupos: híbrido - 45 pacientes que foram operados pela técnica híbrida; total - 45 pacientes operados com CEC. RESULTADOS: No grupo híbrido, o tempo de CEC variou de 20 a 81 minutos e, no grupo total, de 60 a 210 minutos (p<0,001). O tempo de pinçamento aórtico variou de 7 a 70 minutos no primeiro grupo e de 34 a 100 minutos (p<0,001) no segundo grupo. Foi encontrada diferença estatisticamente significativa entre os grupos em relação à incidência de fibrilação atrial e à disfunção renal. CONCLUSÃO: Utilizando-se a técnica híbrida é possível reduzir o tempo de CEC e a incidência de algumas complicações pós-operatórias. Provavelmente, esta redução nas incidências de fibrilação atrial e disfunção renal podem ser explicadas por uma redução na resposta da inflamatória conseqüente a um tempo de CEC menor.OBJECTIVE: To evaluate the decrease of CPB time and its related complications in CABG using a hybrid alternative method. METHODS: Ninety patients were retrospectively analyzed between March 2000 and August 2006. All were treated with three or more grafts and divided into two groups: Group 1 was the hybrid group - 45 patients who had been operated by the hybrid technique; Group 2 was the total group - 45 patients operated in on-pump. RESULTS: In the hybrid group, the CPB time varied from 20 min. to 81 min. In the total group, the CPB time varied from 60 min. to 210 min. (p<0.001). The aorta cross-clamping time varied in the first group from 7 min. to 70 min. In Group 2, from 34 to 100 min. (p<0.001). A statistically significant difference was found between these two groups in relation to the occurrence of postoperative atrium fibrillation and renal dysfunction. CONCLUSION: Using the hybrid technique it is possible to reduce the CPB time, as well as the occurrence of some postoperative complications. Probably, this decreasing in atrial fibrillation and renal dysfunction incidences could be explained due to a less significant inflammatory activation, which is a consequence of a shorter CPB time

Degree of risk related to procedures performed in conjunction with surgical myocardial revascularization in octogenarians

INTRODUCTION/OBJECTIVES: We determined the degree of risk produced by the association of other surgical procedures with surgical myocardial revascularization in octogenarian patients and identified the risk factors that best explain hospital mortality. METHODS: This study was an observational analytical historical cohort study involving octogenarians operated on at our institution between January 1, 2000 and January 1, 2005. We stratified the objective population as follows: Group 1 comprised octogenarians revascularized without associated procedures, and Group 2 comprised octogenarians revascularized with associated procedures. Statistical analyses included the t test for independent samples and multiple logistic regression analysis. Significance was accepted with an alpha error of 5%. RESULTS: Univariate analyses revealed the following clinical and statistically significant variables: hospital mortality (P=0.002), diabetes mellitus (P=0.017), preoperative endocarditis (P=0.001), cardiogenic shock (P=0.019), use of an intra-aortic balloon pump (P=0.026), preoperative risk score (Parsonnet),

Estudo comparativo de duas diferentes modalidades de analgesia controlada pelo paciente após cirurgia cardíaca

INTRODUCTION: Acute and severe pain is frequent in patients who undergo cardiothoracic surgery. Patient controlled analgesia (PCA) can be used to manage postoperative pain. OBJECTIVE: To compare analgesia of morphine PCA alone (without continous infusion) with morphine PCA plus a continuous infusion on postoperative period after cardiac surgery and to evaluate pain scores, morphine consumption, number of demand, patient satisfaction and side effects. METHODS: Randomized trial was conducted to assess patients who underwent cardiac surgery receiving either morphine PCA alone or morphine PCA plus continous infusion. In the post operative period, PCA was started at extubation in both regiments according to randomization. Pain intensity, morphine consumption, number of demand, satisfaction and side effects were assessed at zero, six, twelve, eighteen, twenty four and thirty hours after patients' extubation. RESULTS: The study enrolled 100 patients. 50 patients received morphine PCA alone, (Group A) and 50 patients received morphine PCA plus a background infusion, (Group B). Group B patients had less demand, consumed more morphine and were more satisfied regarding analgesia. No statistical differences were shown between groups related to pain intensity, and side effects. CONCLUSIONS: Pain control was effective and similar in both groups. Morphine PCA alone seems to be better for postoperative pain manage in cardiac surgery, due to its less morphine expense with the same effectiveness.INTRODUÇÃO: A dor aguda e intensa faz parte do cotidiano dos pacientes que realizam cirurgia cardíaca, e para o controle da dor, pode-se dispor da analgesia controlada pelo paciente (PCA -Patient controlled analgesia). OBJETIVO: Comparar a analgesia utilizando PCA sem infusão contínua com PCA mais infusão contínua de morfina no pós-operatório de cirurgia cardíaca e avaliar a intensidade dolorosa, consumo analgésico, número de solicitações analgésicas, satisfação e efeitos colaterais. MÉTODOS: Ensaio clínico randomizado em que foram estudados pacientes submetidos a cirurgias cardíacas, que utilizaram PCA com e sem infusão intravenosa de morfina. No pós-operatório, ao se extubar os pacientes, foi instalada PCA nas duas modalidades, conforme o sorteio. Intensidade dolorosa, consumo analgésico, número de solicitações analgésicas, satisfação e efeitos colaterais foram avaliados no momento da extubação e nas 6, 12, 18, 24 e 30 horas seguintes. RESULTADOS: Foram avaliados 100 pacientes, sendo 50 no grupo (A) que recebeu PCA sem infusão contínua de morfina, e 50 no grupo (B) que utilizou PCA com infusão contínua de morfina. Pacientes do grupo (B) consumiram mais morfina, solicitaram menos vezes, e ficaram mais satisfeitos com a analgesia. Não se observaram diferenças significantes entre os grupos quanto à intensidade da dor e aos efeitos colaterais. CONCLUSÕES: O controle da dor foi eficiente e similar em ambos os grupos estudados. A mesma eficácia de analgesia e o menor consumo de morfina sugerem que PCA sem infusão contínua de morfina seja a melhor opção no controle da dor no pós-operatório de cirurgia cardíaca.Clinics HospitalFederal University of São PauloHeart InstituteHeart Institute Heart Surgical Diseases GroupUNIFESPSciEL

Coronary artery bypass grafting in acute myocardial infarction: analysis of predictors of in-hospital mortality

OBJETIVO: A cirurgia de revascularização miocárdica (CRM) na fase aguda do infarto do miocárdio (IAM) está associada a aumento do risco operatório. O objetivo do estudo foi determinar fatores preditores de mortalidade intra-hospitalar nos pacientes submetidos a CRM no IAM. MÉTODOS: Durante três anos, todos os pacientes submetidos a CRM no IAM foram analisados retrospectivamente, utilizando o banco de dados institucional. Sessenta variáveis por paciente foram avaliadas: 49 variáveis pré-operatórias provenientes dos escores 2000 Bernstein-Parsonnet e EuroSCORE; 4 variáveis pré-operatórias não consideradas por esses escores (tempo entre o IAM e a CRM, valor máximo de CKMB, valor máximo de troponina e supradesnivelamento do segmento ST) e 7 variáveis intraoperatórias [uso de circulação extracorpórea (CEC), tempo de CEC, tipo de cardioplegia, endarterectomia, número de enxertos, uso da artéria torácica interna e revascularização completa]. Análise univariada e multivariada para o desfecho mortalidade intra-hospitalar foram realizadas. RESULTADOS: O tempo médio entre o IAM e a CRM foi de 3,8 ± 3 dias. A mortalidade global foi 19%. Na análise multivariada: idade > 65 anos [OR 16,5 (IC 1,8-152), P=0,013]~ CEC >108 minutos [OR 40 (IC 2,7-578), P=0,007], creatinina > 2 mg/dl [OR 35,5 (IC 1,7-740), P=0,021] e pressão pulmonar sistólica > 60 mmHg [OR 31(IC 1,6-591), P=0,022] foram preditores de mortalidade intra-hospitalar. CONCLUSÃO: Variáveis pré-operatórias clássicas como idade > 65 anos, creatinina > 2 mg/dl e pressão pulmonar sistólica > 60 mmHg foram preditoras de mortalidade intra-hospitalar nos pacientes operados de revascularização miocárdica na fase aguda do infarto