José Glauco Lobo Filho

Experimental model of myocardial infarction induced by isoproterenol in rats

OBJECTIVE: To evaluate and validate, in our laboratory, the essay of myocardial infarction induced by isoproterenol in rats by means of analysis of hematological, biochemical, oxidative stress markers and histopathological parameters. METHODS: Thirty young, male, Wistar rats (145 to 230 g) were randomly allocated in two groups: Sham group, which underwent a virtual myocardial infarction induction, and the Infarction group, which underwent a myocardial infarction induction with isoproterenol. The administrations for the infarction induction were performed during two consecutive days and a 24-hour interval between them. Twenty-four hours after the last administration, rats from both groups were anesthetized and sacrificed for blood sample collection to evaluate complete blood count (CBC) and biochemical parameters (SGOT, SGPT, troponin I, urea and creatinin), obtain myocardial fragments for oxidative stress markers analyses (catalase activity and glutathione concentrations) as well as histopathological examinations. RESULTS: There were no death cases in the Sham group, while the mortality rate in the Infarction group was 25%. Myocardial infarction induction with isoproterenol raised leukocytes and neutrophils counts, SGOT, troponin I and urea concentrations, reduced catalase enzyme activity and glutathione concentrations in the myocardium and let to histopathological concentrations as well. It did not exert alterations in terms of hemoglobin, SGPT and creatinin concentrations. CONCLUSIONS: The isoproterenol-induced myocardial infarction essay in rats was adequately reproduced in our laboratory, causing alterations in hematological, biochemical, oxidative stress markers and histopathological parameters.OBJECTIVE To evaluate and validate, in our laboratory, the essay of myocardial infarction induced by isoproterenol in rats by means of analysis of hematological, biochemical, oxidative stress markers and histopathological parameters. METHODS Thirty young, male, Wistar rats (145 to 230 g) were randomly allocated in two groups: Sham group, which underwent a virtual myocardial infarction induction, and the Infarction group, which underwent a myocardial infarction induction with isoproterenol. The administrations for the infarction induction were performed during two consecutive days and a 24-hour interval between them. Twenty-four hours after the last administration, rats from both groups were anesthetized and sacrificed for blood sample collection to evaluate complete blood count (CBC) and biochemical parameters (SGOT, SGPT, troponin I, urea and creatinin), obtain myocardial fragments for oxidative stress markers analyses (catalase activity and glutathione concentrations) as well as histopathological examinations. RESULTS There were no death cases in the Sham group, while the mortality rate in the Infarction group was 25%. Myocardial infarction induction with isoproterenol raised leukocytes and neutrophils counts, SGOT, troponin I and urea concentrations, reduced catalase enzyme activity and glutathione concentrations in the myocardium and let to histopathological concentrations as well. It did not exert alterations in terms of hemoglobin, SGPT and creatinin concentrations. CONCLUSIONS The isoproterenol-induced myocardial infarction essay in rats was adequately reproduced in our laboratory, causing alterations in hematological, biochemical, oxidative stress markers and histopathological parameters.

Surgical results of coronary artery bypass grafting without cardiopulmonary bypass: analysis of 3,410 patients

OBJETIVO: Nos ultimos anos, tem-se observado um grande avanco na cirurgia de revascularizacao miocardica sem circulacao extracorporea (RMSCEC). Esse desenvolvimento deveu-se a combinacao dos avancos da tecnica cirurgica e ao desenvolvimento de instrumentos que possibilitam a realizacao deste procedimento nas mais variadas situacoes. Este e um estudo retrospectivo, que visa avaliar nossa experiencia com este procedimento nos ultimos 11,5 anos. Os autores enfatizam o rapido progresso do metodo nos ultimos anos, suas indicacoes, contra-indicacoes e resultados. METODO: No periodo de agosto de 1991 e dezembro de 2002, 3.410 pacientes consecutivos, portadores de angina do peito, foram submetidos a cirurgia de revascularizacao miocardica sem circulacao extracorporea. A idade variou de 13 a 93 anos (63 12,0 anos), sendo 58% dos pacientes do sexo masculino. A angina foi classificada segundo a Canadian Cardiovascular Society, sendo 6,1% na classe I, 6,8% na classe II, 46,3% na classe III e 40,8% na classe IV. RESULTADOS: A mortalidade intra-operatoria foi baixa (0,4%). A mortalidade hospitalar (trinta dias de pos-operatorio) foi de 2,58%. A mortalidade e morbidade, no grupo dos pacientes octogenarios, foram extremamente baixas em relacao aos pacientes operados com circulacao extracorporea (2,2% x 12,6%) (p<0,001). As complicacoes pos-operatorias que nao resultaram em obito foram de 7,6%. No ultimo ano, nao observamos diferenca entre o numero de condutos nos pacientes operados com e sem CEC [com CEC 2,81,2 e sem CEC 2,80,8 (NS)]. Infarto agudo do miocardio foi a complicacao nao fatal mais frequente, observada em 2,8% dos pacientes. O tempo medio de permanencia na UTI foi de 22,3 horas. CONCLUSOES: A RMSCEC, usada como tecnica de revascularizacao em pacientes multiarteriais, e um procedimento reproduzivel e apresenta resultados semelhantes aos obtidos com a operacao convencional com CEC. Nesta serie foi possivel revascularizar o miocardio sem circulacao extracorporea em mais de 95% dos pacientes, tornando assim, a principio, todos os pacientes, com indicacao de revascularizacao miocardica, potenciais candidatos a operacao de RMSCEC.

Myocardial revascularization surgery using composite Y-graft of the left internal thoracic artery: blood flow analysis

OBJECTIVE: To assess the left internal thoracic artery (LITA) flow pattern, when it was used to supply the left anterior descending artery (LADA) and another branch from the left coronary artery system (LCAS). METHODS: In the following study, the left internal thoracic artery flow was investigated by echocardiography Doppler, at rest and under dobutamine stress, in two twenty-patient groups. Group A consisted of patients who received only a pedicled LITA graft to the LADA. Group B consisted of patients who received a pedicled LITA graft associated with a vein graft to supply the LADA and another artery from the LCAS. The angiographic study showed graft patency in all patients from both groups. The following parameters were used: systolic flow (SF), diastolic flow, total flow, total flow in stress/total flow at rest ratio (TFS/TFR), systolic peak velocities (SPV), diastolic peak velocities and systolic peak velocity/diastolic peak velocity ratio. RESULTS: All analysed parameters were considered statistically significant, except SF, TFS/TFR and SPV. CONCLUSIONS: We concluded that in the same conditions and methodology, the LITA flow in the composite graft (group B) is higher than in the free graft (group A), which shows the great flow adaptability of LITA to respond to flow demand.

Right atrial myxoma prolapsing into the right ventricle

We report on a rare case of a 67-year-old woman with a right atrial myxoma prolapsing into the right ventricle in the diastolic phase. These tumors comprise approximately 18% of all cardiac myxomas, which occur in 0.0017% of collected autopsy series.

Vineberg's Procedure Modified Technique: Flow Analysis, Immediate Postoperative Results and Angiographic Evaluation

Abstract  Background: The purpose of this study was to evaluate angiographic results of patients subjected to a technique variation of Vinebergs procedure, as well as their morbidity and mortality in immediate postoperative period, and to analyze the flow of grafted left internal thoracic artery (LITA) at rest and under stress. Methods: Between September 1999 and April 2002 eight patients were operated upon, with implant of the internal thoracic artery (ITA) in the intimal layer of the left ventricle (LV) muscle. After 6 months, they underwent angiographic and Doppler evaluation. According to Doppler study of LITA, the sample was divided in two groups: “Vineberg group,” formed by eight patients; and “control group” consisting of 20 patients whose LITA directly revascularize the anterior interventricular artery (AIV). Angiography showed patency of all grafts in both groups. Blood flow and flow velocity in grafts were measured by Doppler echocardiography. T‐test for paired and unpaired samples were used for statistical analysis. Results: There were no deaths or complications in immediate postoperative period. Angiography showed 100% patency. The total flow (TF) of Vineberg group was 55% of the flow in the control group. In both groups, the TF increased with the stress. Conclusions: This Vinebergs technique modification can be successfully used in patients who cannot undergo traditional direct revascularization due to its low rates of morbidity and mortality and a high rate of patency, providing a significant blood flow both at rest and under stress.

Angiographic follow-up of myocardial revascularization using the vineberg procedure correlated with intraoperative imaging.

,2 , in more than 60 patients who were unable to undergo direct myocardial revascularization with ITA anastomosis to the anterior interventricular artery (AIA). In the majority of these unusual cases, the AIA was hypoplastic, with difuse atheromatous disease, which is incompatible with an endarterectomy procedure and direct revascularization or angioplastic surgery. As per current literature, the Vineberg procedure is a last resort therapeutic option 3-5 . In regard to angiogenesis, which is one of the justifications for the efficacy of the Vineberg procedure, the medical literature demonstrates the induction of angiogenesis in an ischemic human myocardium; other studies suggest a beneficial association of this procedure with angiogenic therapy 6-10 . We believe that in the near future, patients will be able to profit from this powerful treatment combination.

A novel composite coronary bypass graft strategy using the saphenous vein bridge: could the venous valves induce worse patency results?

Jose Glauco Lobo Filho*, Heraldo G. Lobo Filho, Matheus D. Pimentel and Marilia L. Montenegro a Department of Surgery, Walter Cantidio University Hospital of the Federal University of Ceara, Fortaleza, Brazil b Department of Surgery, Federal University of Ceara, Fortaleza, Brazil c Federal University of Ceara, Fortaleza, Brazil d Christus College, Fortaleza, Brazil Received 7 May 2014; accepted 12 June 2014

Doppler echocardiographic flow pattern of the left internal thoracic artery following myocardial revascularization using a composite graft

Doppler echocardiographic studies of left internal thoracic artery (LITA) grafts, pedicled to the anterior interventricular artery (AIA) became a significant non-invasive method to evaluate graft blood flow and patency at the end of the 90’s. A detailed comparison of blood flow from an in situ LITA and an implanted LITA graft reveals that the in situ LITA has a predominantly systolic flow pattern, whereas the LITA pedicled to the AIA shows a considerable increase of diastolic flow, compatible to the flow pattern in the coronary arteries. Another important observation is that the LITA adapts well to flow demand, and therefore can be used in composite grafts for revascularization of more than one coronary artery1.

Standardization of the sodium heparin dose used in off-pump myocardial revascularization surgery

OBJETIVO: Propor uma metodologia de anticoagulacao com heparina sodica monitorizada pelo Tempo de Coagulacao Ativada (TCA) nos pacientes submetidos a cirurgia de revascularizacao miocardica (RM) sem circulacao extracorporea (CEC), que promova uma anticoagulacao segura (TCA >200 segundos), utilizando uma dose inicial de 1mg heparina sodica/kg de peso. METODO: Quarenta pacientes (30 homens e 10 mulheres), entre 41 e 85 anos, foram submetidos a cirurgia de RM sem CEC, utilizando uma dose inicial de 1mg heparina sodica/kg de peso. Dez minutos apos a administracao da droga, quando TCA > 200 segundos, iniciava-se a confeccao das anastomoses coronarianas. Caso contrario, administrava-se 0,5mg/kg de heparina suplementar. Durante a cirurgia, a cada 30 minutos, novos valores de TCA foram obtidos. Concluidas as anastomoses coronarianas, a heparina foi revertida na proporcao de 1:1 utilizando cloridrato de protamina. RESULTADOS: O valor medio de TCA dez minutos pos-heparinizacao foi de 372,2(+/-104,31) segundos, sem variacao estatisticamente significante entre os sexos ou grupos etarios (p>0,05). Os valores de TCA, 30 e 60 minutos pos-heparinizacao, mantiveram-se acima de 200 segundos. Aos 30 minutos, verificou-se diferenca estatisticamente significante dos valores do TCA entre os sexos e diferentes idades (p<0,05). Apos reversao com protamina, todos os pacientes retornaram aos seus niveis basais de hemostasia (TCA < 200s). CONCLUSOES: Os resultados apresentados demonstram a seguranca e eficacia da anticoagulacao monitorizada pelo TCA nos pacientes submetidos a RM sem CEC, utilizando doses de 1mg heparina sodica/kg de peso, capaz de manter-se efetiva durante todo o procedimento cirurgico, independentemente de variaveis como sexo ou idade.

Intraoperative Analysis of Flow Dynamics in Arteriovenous Composite Y Grafts

Objective Composite graft of left internal thoracic artery and great saphenous vein in revascularization of the left coronary system is a technique well described in literature. The aim of this study is to analyze blood flow dynamics in this configuration of composite graft especially in what concerns left internal thoracic arterys adaptability and influence of great saphenous vein segment on left internal thoracic arterys flow. Methods Revascularization of left coronary system with composite graft, with left internal thoracic artery revascularizing the anterior interventricular artery and a great saphenous vein segment, anastomosed to the left internal thoracic artery, revascularizing another branch of the left coronary system, was performed in 23 patients. Blood flow was evaluated by transit time flowmetry in all segments of the composite graft (left internal thoracic artery proximal segment, left internal thoracic artery distal segment and great saphenous vein segment). Measures were performed in baseline condition and after dobutamine-induced stress, without and with non-traumatic temporary clamping of the distal segments of the composite graft. Results Pharmacological stress resulted in increase of blood flow values in the analyzed segments (P<0.05). Non-traumatic temporary clamping of great saphenous vein segment did not result in statistically significant changes in the flow of left internal thoracic artery distal segment, both in baseline condition and under pharmacological stress. Similarly, non-traumatic temporary clamping of left internal thoracic artery distal segment did not result in statistically significant changes in great saphenous vein segment flow. Conclusion Composite grafts with left internal thoracic artery and great saphenous vein for revascularization of left coronary system, resulted in blood flow dynamics with physiological adaptability, both at rest and after pharmacological stress, according to demand. Presence of great saphenous vein segment did not alter physiological blood flow dynamics in distal segment of left internal thoracic artery.