Comparison of the internal thoracic artery flow dissected by video endoscopy or conventional technique

ABSTRACT Purpose: To compare the blood flow in the internal thoracic artery when dissected endoscopically in a conventional manner, in addition to develop a reliable experimental training model for the surgical team. Methods: Paired experimental study. Ten pigs were operated and had both internal thoracic arteries dissected, the right with a conventional technique and the left by video endoscopy. The main outcomes to be studied were flow, length, and time of dissection of each vessel. Results: Blood flow measurements were performed with mean heart rate of 100 ± 16 bpm and mean arterial pressure of 89.7 ± 13 mm Hg. The mean blood flow of endoscopic dissection of the internal thoracic artery was 170.2 ± 66.3 mL/min and by direct view was 180.8 ± 70.5 (p = 0.26). Thus, there was no statistically significant difference between the flows, showing no inferiority between the methods. Conclusions: The minimally invasive dissection of the internal thoracic artery was shown to be not inferior to the dissection by open technique in relation to the blood flow in the present experimental model. In addition, the model that we replicated was shown to be adequate for the development of the learning curve and improvement of the endoscopic abilities.

Adverse Events and Risk Factors of Blood Transfusion in Cardiovascular Surgery: A Prospective Cohort Study

Abstract Background: Hemodilution, transoperative bleeding and cardiopulmonary bypass (CPB) are some of the factors associated with high transfusion rates in cardiac surgery. Objective: To analyze the incidence of blood transfusion and early postoperative outcomes in cardiac surgery patients. Methods: Cohort study of patients undergoing cardiac surgery in a university hospital, consecutively enrolled from May 2015 to February 2017. Data were prospectively collected and comparisons were made between two patients' groups: transfused and not transfused. Student's t-test, chi-square test, and logistic regression were used, and a p-value < 0.05 was considered significant. Results: Among the 271 patients evaluated, 100 (37%) required transfusion in the transoperative (32.1%) and/or postoperative periods (19.5%). The following predictors of transfusion were identified by multivariate analysis: EuroScore II (OR 1.2); chronic kidney disease (CKD) (OR 3.2); transoperative bleeding ≥ 500 mL (OR 6.7); baseline hemoglobin (Hb) ≤ 10 g/dL (OR 11.5); activated partial thromboplastin time (aPTT) (OR 1.1) and CPB duration (OR 1.03). Transfusion was associated with prolonged mechanical ventilation (≥ 24h) (2.4% vs. 23%), delirium (5.9% vs. 18%), bronchopneumonia (1.2% vs. 16%), acute renal failure (3.5% vs. 25%), acute on CKD (0.6% vs. 8%), stroke or transient ischemic attack (1.8% vs. 8%), intensive care unit stay ≥ 72 h (36% vs. 57%), longer hospital stay (8 ± 4 days vs. 16 ± 15 days), as well as increased early mortality (1.75% vs. 15%). Conclusion: EuroScore II, CKD, major transoperative bleeding, preoperative Hb and aPTT values and CPB time were independent predictors of transfusion, which was associated with a higher rate of adverse outcomes, including early mortality.

Criação e implementação de um banco de dados cirúrgico totalmente informatizado baseado nas ferramentas Google: experiência inicial em cirurgia cardiovascular / Design and implementation of a fully electronic surgery database based on Google tools: an initial experience in cardiovascular surgery

RESUMO Objetivo: descrever de maneira prática e detalhada a criação de uma plataforma totalmente informatizada para coleta, armazenamento e análise de dados, inicialmente proposta para cirurgia cardiovascular, com interfaces reprodutíveis e aplicáveis a outras especialidades cirúrgicas, bem como, apresentar a experiência inicial de trabalho com esta ferramenta e os resultados preliminares obtidos após sua implementação em um hospital universitário terciário brasileiro. Métodos: a plataforma foi desenvolvida com base nas ferramentas Google, gratuitas, de fácil utilização e amplamente acessíveis. Desde o início desta iniciativa, em maio de 2015, até a análise preliminar, em fevereiro de 2017, dados de 271 pacientes, consecutivos, submetidos à cirurgia cardiovascular foram prospectivamente recordados e analisados. Resultados: a iniciativa foi implementada com pleno sucesso, com 100% dos pacientes incluídos e sem perda de qualquer variável em um banco de dados composto por mais de 500 variáveis. As complicações pós-operatórias imediatas mais frequentes foram: fibrilação atrial (22,5%), broncopneumonia (10,7%), delirium (10,3%), insuficiência renal aguda (10%), acidente vascular encefálico (5%) e morte (7%). Comparando-se as taxas de mortalidade no primeiro e segundo anos da iniciativa, uma redução de 10,8% para 4% (p=0,042), respectivamente, foi evidenciada. Conclusão: a nova proposta de coleta e armazenamento de dados apresentada neste trabalho mostrou-se plenamente factível e efetiva. Por serem gratuitas, de fácil manuseio e universalmente acessíveis, estas ferramentas podem ser úteis a outras especialidades cirúrgicas que desejem desenvolver métodos de avaliação de sucesso e complicações pós-operatórios, bem como, programas de melhoria de qualidade.

ABSTRACT Objective: to describe, in a practical and step-by-step manner, the construction of a fully electronic platform for data collection, storage, and analysis, initially proposed for cardiovascular surgery, with interfaces that are reproducible and applicable to other surgical specialties, as well as to present the initial work experience with this instrument in cardiac surgery and the preliminary results obtained after its implementation in a Brazilian tertiary university hospital. Methods: the platform was developed based on Google tools, which are free, easy to use, and widely accessible. From the beginning of this initiative, in May 2015, to the preliminary analysis, in February 2017, data from 271 consecutive patients submitted to cardiovascular surgery were prospectively recorded and preliminarily analyzed. Results: the initiative was implemented with full success, with 100% of patients included and without loss of any variable, in a database composed of more than 500 variables. The most frequent immediate postoperative complications were: atrial fibrillation (22.5%), bronchopneumonia (10.7%), delirium (10.3%), acute renal failure (10%), stroke (5%), and death (7%). Comparing mortality rates in the first and second years of the initiative, a reduction from 10.8% to 4% (p=0.042), respectively, was evidenced. Conclusion: the new proposal of data collection and storage presented in this work was fully feasible and effective. It may be useful to other surgical specialties that wish to develop methods to evaluate success and postoperative complication rates, as well as quality improvement programs.

Spontaneous left anterior descending coronary artery dissection requiring coronary artery bypass surgery

Abstract Introduction: Spontaneous coronary artery dissection is a sudden separation between the layers of a coronary artery wall, non-iatrogenic or trauma related, that has been recognized as an important cause of myocardial infarction. Objective: To report an emblematic case, in terms of angiographic images, clinical presentation and predisposing factors, whose clinical management failure led to surgical intervention. Methods: A previously healthy 48-year-old male farmer was admitted to the emergency room complaining of anterior chest pain described as "tearing", which started after physical exertion. Anterior wall ST-segment depression was observed in the electrocardiogram and troponin levels were increased. The patient then underwent coronary catheterization. Angiography showed a tortuous left anterior descending coronary artery with a dissection line involving proximal and middle segments, resulting in mild to moderate luminal stenosis. At first, a conservative approach was chosen. Control cardiac catheterization, 3 months later, showed dissection progression to the distal segment. Results: The patient was referred to surgical treatment. Internal thoracic artery and a great saphenous vein graft were used to revascularize the target vessels. He had an uneventful postoperative course. Conclusion: In this report, we describe a typical clinical manifestation of an uncommon cause of acute myocardial infarction. The dissection was started by an extreme physical effort, which is a known triggering factor. Management of these cases is always challenging because there are no evidence-based therapies or guideline-based recomendations.

Mediastinitis: mortality rate comparing single-stage surgical approach and preconditioning of wound / Mediastinite: mortalidade comparando abordagem cirúrgica em tempo único e o pré-condicionamento da ferida operatória

OBJECTIVE: This study aims to compare hospital mortality rate of surgical debridement followed by primary wound closure versus surgical debridement with closure after preconditioning of the wound. METHODS: A historical cohort of 43 patients with postoperative mediastinitis type III and IV between 2000 and 2008. The diagnosis of mediastinitis was based on physical examination and laboratory tests. Patients were divided into two groups: patients who received the protocol of preconditioning of the wound (Group 2) and those who did not (Group 1). RESULTS: Of the 43 patients, 15 received the protocol and were assigned to Group 2, and 28 patients to Group 1. Myocardial revascularisation was the surgical intervention most affected by infection, accounting for 69.8% of patients in Group 1 and 64.3% in Group 2.Staphylococcus aureus was the predominant pathogen, accounting for 58.1% of all cases, 50% in Group 1 and 73.3% in Group 2. Hospital mortality rate was 42.9% in Group 1 and 20% in Group 2 (P=1.86), with relative risk of 2.14 and CI [0.714-6.043]. Among the 28 (65.1%) patients who underwent single-stage surgical approach, 12 (27.9%) underwent primary wound closure with irrigation, seven (16.3%) only primary closure, six (14%) omental flap, and three (7%) pectoralis muscle flap. CONCLUSION: Due to the lack of established guidelines, the choice of the surgical approach is based largely on low-level evidence references. Preconditioning of the wound appears to lead to a reduction in mortality in these patients, being a good surgical option.

OBJETIVO: Este estudo tem por objetivo comparar a taxa de mortalidade intra-hospitalar do debridamento cirúrgico seguido de fechamento da ferida operatória, com a do debridamento cirúrgico com fechamento após pré-condicionamento da ferida. MÉTODOS: Coorte histórica composta por 43 pacientes portadores de mediastinite pós-operatória tipo III e IV entre os anos de 2000 e 2008. O diagnóstico de mediastinite foi feito com base em exames físico e laboratoriais. Os pacientes foram divididos em dois grupos, os que seguiram o protocolo de pré-condicionamento da ferida operatória (Grupo 2) ou não (Grupo 1). RESULTADOS: Dos 43 pacientes, 15 seguiram o protocolo e foram alocados no Grupo 2. A revascularização do miocárdio foi a cirurgia mais afetada pela infecção, sendo responsável por 69,8% dos pacientes no Grupo 1 e 64,3% no Grupo 2. O Staphylococcus aureus foi o germe mais prevalente, sendo responsável por 58,1% do total dos casos, sendo 50% e 73,3%, respectivamente, nos Grupos 1 e 2. A mortalidade intra-hospitalar foi de 42,9% no Grupo 1 e de 20% no Grupo 2 (P=1,86), com risco relativo de 2,14 e IC [0,714-6,043]. Entre os 28 (65,1%) pacientes do estudo que seguiram a abordagem cirúrgica em um único tempo, 12 (27,9%) foram submetidos a fechamento primário com irrigação, sete (16,3%), a fechamento primário isolado, seis (14%), rotação de retalho de epíplon, e três (7%), interposição de retalho de músculo peitoral. CONCLUSÃO: Na ausência de uma diretriz bem estabelecida, a escolha do tipo de intervenção cirúrgica é feita utilizando-se referências com baixo nível de evidência. O pré-condicionamento da ferida operatória parece levar a redução da mortalidade nesses pacientes, sendo uma boa alternativa cirúrgica.

Resultados de pacientes submetidos à cirurgia de substituição valvar aórtica usando próteses mecânicas ou biológicas / Outcomes of patients subjected to aortic valve replacement surgery using mechanical or biological prostheses

OBJETIVO: Esse estudo avalia resultados em pacientes submetidos à cirurgia para troca valvar aórtica utilizando substituto biológico ou mecânico, com poder de relevância na seleção do tipo da prótese. MÉTODOS: Foram selecionados, randomicamente, 301 pacientes submetidos à cirurgia para troca valvar aórtica entre 1990 e 2005, com seguimento máximo de 20 anos. RESULTADOS: Sobrevivência em 5, 10 e 15 anos após cirurgia utilizando substituto mecânico foi de 83,9%, 75,4% e 60,2% e, para substituto biológico, foi de 89,3%, 70,4% e 58,4%, respectivamente (P=0,939). Fatores associados com óbito foram: idade, obesidade, doença pulmonar, arritmias, eventos hemorrágicos e insuficiência valvar aórtica. Probabilidade livre de reoperação desses pacientes em 5, 10 e 15 anos após cirurgia utilizando substituto mecânico foi de 97,9%, 95,8% e 95,8% e, para bioprótese, foi de 94,6%, 91,0% e 83,3%, respectivamente (P=0,057). Fatores associados com reoperação foram: insuficiência renal, endocardite de prótese e idade. Probabilidade livre de eventos hemorrágicos em 5, 10 e 15 anos após cirurgia utilizando substituto mecânico foi de 94,5%, 91,7% e 91,7% e, para bioprótese, foi de 98,6%, 97,8% e 97,8%, respectivamente (P=0,047). Fatores associados com eventos hemorrágicos foram: insuficiência renal e prótese mecânica. CONCLUSÕES: Os autores concluíram que: 1) mortalidade foi estatisticamente semelhante entre os grupos; 2) características basais dos pacientes foram os maiores determinantes de mortalidade tardia após a cirurgia; 3) houve tendência à reoperação para o grupo com bioprótese; 4) pacientes com prótese mecânica tiveram mais eventos hemorrágicos ao longo do tempo; 5) dados encontrados no presente estudo são concordantes com a literatura atual.

OBJECTIVE: This paper evaluates outcomes in patients subjected to surgery for replacement of the aortic valve using biological or mechanical substitutes, where selection of the type of prosthesis is relevant. METHODS: Three hundred and one patients, randomly selected, who had been subjected to aortic valve replacement surgery between 1990 and 2005, with a maximum follow-up period of 20 years. RESULTS: Survival at 5, 10 and 15 years after surgery using mechanical substitute was 83.9%, 75.4% and 60.2% and, for biological substitute, was 89.3%, 70.4% and 58.4%, respectively (P=0.939). Factors associated with death were: age, obesity, pulmonary disease, arrhythmia, bleeding and aortic valve failure. Probability free of reoperation for these patients at 5, 10 and 15 years after surgery using mechanical substitute was 97.9%, 95.8% and 95.8% and, for those using bioprostheses, was 94.6%, 91.0% and 83.3%, respectively (P=0.057). Factors associated with reoperation were: renal failure, prosthesis endocarditis and age. Probability free of bleeding events at 5, 10 and 15 years after surgery using mechanical substitute was 94.5%, 91.7% and 91.7% and, for bioprostheses, was 98.6%, 97.8% and 97.8%, respectively (P=0.047). Factors associated with bleeding events were: renal failure and mechanical prostheses. CONCLUSIONS: The authors have concluded that: 1) mortality was statistically similar in the groups; 2) patient characteristics at baseline were a major determinant of late mortality after surgery; 3) there was a tendency toward reoperation in the bioprostheses group; 4) patients using mechanical prosthesis had more bleeding events as time passed; 5) data presented in this paper is in accordance with current literature.

Análise ultra-estrutural do miocárdio usando solução cardioplégica cristalóide com e sem procaína em pacientes submetidos à troca valvar aórtica / Ultrastructural study of the myocardium using cardioplegic crystalloid solution with and without procaine in patients undergoing aortic valve replacement

OBJETIVO: Avaliar as alterações ultra-estruturais de dois tipos de cardioplegia (com e sem procaína) em corações de pacientes submetidos a troca valvar aórtica eletiva. MÉTODOS: Foram estudados 18 pacientes submetidos a circulação extracorpórea para troca valvular aórtica eletiva, no Hospital de Clínicas de Porto Alegre num período de 10 meses. Cada paciente foi distribuído aleatoriamente em dois grupos: grupo A - oito pacientes que receberam solução cardioplégica sem procaína; grupo B - Dez pacientes que receberam solução cardioplégica com procaína. Em ambos os grupos, o saco pericárdico foi irrigado com solução salina hipotérmica. As biópsias miocárdicas foram realizadas em três momentos: I - antes da parada isquêmica, II- no final do período isquêmico e III-15 minutos após a reperfusão. RESULTADOS: A avaliação ultra-estrutural comparando os grupos nos três momentos não demonstrou diferenças significativas, sendo a média dos escores no grupo A, nos momentos I, II, e III, de 0,1 ± 0,2; 0,4 ± 0,3 e 0,4 ± 0,4. No grupo B, a médio dos escores foi 0,2 ± 0,2; 0,4 ± 0,3 e 0,7 ± 0,2, respectivamente), nos momentos I, II, e III. A curva de CK-MB foi similar entre os dois grupos. O retorno espontâneo do ritmo cardíaco, pós-despinçamento, ocorreu em 70% dos pacientes no grupo B e, em 12,5% no grupo A (p=0,024). CONCLUSÃO: As duas soluções testadas protegeram o miocárdio de forma eficaz e não foi possível demonstrar, em nível ultra-estrutural, a superioridade da solução contendo procaína. Constatou-se que o retorno ao ritmo espontâneo do coração após o despinçamento aórtico foi significativamente maior no grupo que utilizou procaína adicionada à solução.

OBJECTIVE: The aim of this study was to assess whether the presence of procaine in crystalloid cardioplegic solution increases myocardial protection at the ultra structural level. METHODS: Eighteen patients that underwent aortic valve replacement in the Hospital de Clínicas de Porto Alegre over a 10-month period were studied. They were randomly allocated into two groups: group A - eight patients receiving cardioplegia without procaine; group B - ten patients receiving cardioplegia with procaine. Myocardial biopsies were performed in three different periods: 1st - before ischemic arrest, 2nd - at the end of ischemic arrest, and 3rd -15 minutes after reperfusion. RESULTS: The ultra structural analysis comparing the groups in the three moments did not show any statistically significant difference. The mean score in group A at moment I, II and III was 0.1 ± 0.2; 0.4 ± 0.3; 0.4 ± 0.4, and group B 0.2 ± 0.2; 0.4 ± 0.3; 0.7 ± 0.2. Comparative analysis of CK-MB was similar. The spontaneous return to sinus rhythm after aortic declamping in group B occurred in 70% and in group A 12.5% (p=0.024). CONCLUSION: Both cardioplegic solutions tested were equally effective in myocardial preservation, and we could not demonstrate at the ultrastructural level any benefit when procaine was added. The spontaneous return to sinus rhythm after aortic declamping was significantly greater when procaine was added.

Experimental model for the study of chronic renal ischemia in rats: morphologic, histological and ultra-structural analysis

PURPOSE: To evaluate a model of chronic renal ischemia in rats and to characterize the effects on renal tissue. METHODS: 168 Wistar rats were divided into two equal groups, control (GC) and ischemia (GI). The animals of the GI (n=84) were submitted to partial ligation of the left renal artery, and the animals of GC (n=84) stayed with the renal artery intact. In seven successive and identical periods of time, in weekly intervals, 12 animals of each group were submitted to nephrectomy, with morphometric determinations and histological and ultra-structural analysis. RESULTS: The GI presented progressive reduction in renal weight, volume and cortical thickness observed from the 7th day of the experiment, reaching maximum degree in the 49th day (p < 0.05). The proximal tubular atrophy in the GI was observed in 75/84 analysis (89,2 percent), with highly significant difference among the groups starting from the 7th day (p=0 .0009) and in the other periods of the experiment (p=0 .00001). The most prevalent interstitial alteration was the infiltrate, present in 98,8 percent of the GI, with highly significant difference among the groups in the whole experiment (p=0 .00001). Ultra-structural analysis didn't demonstrate glomerular lesions, evidencing that the glomerule preserves its intact architecture during chronic ischemia. CONCLUSION: The model showed that chronic renal ischemia in rats provokes progressive renal atrophy, with preservation of glomerular structure.

OBJETIVO: Avaliar um modelo de isquemia renal crônica em ratos e caracterizar os efeitos no tecido renal. MÉTODOS: Utilizaram-se 168 ratos Wistar divididos em dois grupos iguais, controle (GC) e isquemia (GI). Os animais do GI (n=84) foram submetidos à ligadura parcial da artéria renal esquerda, e os animais do GC (n=84) permaneceram com a artéria renal intacta. Em sete períodos de tempo sucessivos e iguais, em intervalos semanais, 12 animais de cada grupo foram submetidos à nefrectomia, com determinações morfométricas e análises histológica e ultra-estrutural. RESULTADOS: O GI apresentou redução progressiva no peso, volume e espessura cortical renal a partir do 7° dia do experimento, atingindo grau máximo no 49° dia (p < 0.05). A atrofia tubular proximal no GI ocorreu em 75/84 análises (89,2 por cento), com diferença altamente significativa entre os dois grupos a partir do 7° dia (p=0.0009) e nos demais períodos do experimento (p=0.00001). A alteração intersticial mais comum no GI foi o infiltrado, presente em 98,8 por cento, com diferença altamente significativa entre os dois grupos (p=0.00001). A análise ultra-estrutural não demonstrou lesões glomerulares, evidenciando que os glomérulos preservam sua arquitetura intacta durante a isquemia crônica. CONCLUSÃO: O modelo mostrou que a isquemia renal crônica em ratos provoca atrofia renal progressiva, com preservação da estrutura glomerular.