Fatores de risco para disfunção e para não função primária do fígado transplantado em um contexto brasileiro / Risk factors for dysfunction and primary non-function of the transplanted liver in a Brazilian context

A disfunção precoce do enxerto é descrita como mau funcionamento inicial, função marginal ou retardo na função e incide entre 7% e 27% dos pacientes transplantados de fígado. A não função primária é a perda do enxerto e incide entre 1,4% e 8,4% nessa população. O presente estudo foi conduzido para analisar fatores de risco para disfunção e para não função primária de fígados transplantados. Foram pesquisados fatores do doador, do enxerto, do paciente e da logística do transplante. Trata-se de um estudo epidemiológico, tipo coorte histórica conduzido com 180 prontuários de pacientes transplantados e admitidos na Unidade de Terapia Intensiva, cujos doadores estavam em morte encefálica. Todos os transplantes foram realizados no Hospital das Clínicas da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil, entre 2012 e 2018. Análises estatísticas descritiva, bivariada e multivariada foram realizadas usando o método de Kaplan-Meier e o teste Log-rank. Associação entre os fatores de risco e os desfechos foi estabelecida aplicando a regressão de Cox e o processo de seleção Backward, ajustada pelo Hazard ratio. Verificou-se que os receptores de fígado tinham idade média de 52,1 anos; em sua maioria homens brancos. As indicações do transplante foram: doença alcoólica, 31,7%; doença metabólica e Hepatite viral, 26,1%; tumor, 22,2%; doença colestática, 17,8% e doença vascular, 2,8%. Índice de Massa Corporal igual ou superior a 30 kg/m² foi encontrado em 3,9%. O escore médio do Model for End-Stage Liver Disease foi de 23 e a creatinina sérica média foi de 1,35mg/dl. Em relação aos doadores, a idade média foi de 37,6 anos, sendo 39,4% do sexo feminino. As causas da morte encefálica foram acidente vascular cerebral em 86 (47,8%), traumatismo craniano em 77 (42,8%) e por outras causas 17 (9,4%). A aspartato aminotransferase foi, em média, 77,20 UI/L, a alanina aminotransferase foi, em média, 60,42 UI/L. Sódio sérico >160 mmol/l ocorreu em 18,6% e a Gamaglutamiltransferase média foi de 77 UI/L. O Índice de Risco do Doador médio foi de 1,476. Quanto ao enxerto verificou-se que sua origem foi local em 37,8%; regional, em 56,7% e nacional, em 5,5% dos casos. O tempo de isquemia fria (>10 horas) ocorreu em 58 (32,2%). O tempo de isquemia quente (> 60 minutos) ocorreu em 14 (9,9%) % dos transplantes e o tempo médio da cirurgia do receptor foi de 6,1 horas. Estes receberam, em média, 4 U de plaquetas e 5 (2.8%) receberam Plasma Fresco Congelado > 30U. O Equilíbrio do Risco médio foi de 10. A evolução clínica9 normal ocorreu em 66 (36,7%) dos pacientes. A disfunção precoce do enxerto foi identificada em 104 (57,8%) e a não função primária em 10 (5,5%). Encontrou-se que o doador do sexo feminino, o tempo de isquemia quente do enxerto superior a 60 minutos e o consumo de Plasma Fresco Congelado > 30 U pelo receptor, constituem risco aumentado para disfunção precoce do enxerto nesta amostra. O fator de risco para a não função primária foi o volume de plaquetas consumido pelo receptor. O controle desses fatores de risco contribui para a função adequada do fígado após o transplante e melhora da sobrevida dos enxertos e dos pacientes.

Early graft dysfunction is described as initial malfunction, marginal function or delayed function, and it affects between 7% and 27% of liver transplant patients. The primary nonfunction is graft loss, and it affects between 1.4% and 8.4% of this population. The present study was conducted to analyze risk factors for dysfunction and non-primary function of transplanted livers. Donor, graft, patient, and transplant logistics factors were researched. This is an epidemiological study, with a historical cohort conducted with 180 medical records of transplanted patients admitted to the Intensive Care Unit, whose donors were brain dead. All transplants were performed at the Hospital das Clínicas, Federal University of Minas Gerais, Belo Horizonte, Brazil, between 2012 and 2018. Descriptive, bivariate, and multivariate statistical analyzes were performed using the Kaplan-Meier method and the Log-rank test. Association between risk factors and outcomes was assessed by Cox regression and the Backward selection process, adjusted by the Hazard ratio. The liver receptors were mostly white males with an average age of 52.1 years. Transplant indications were: alcoholic disease, 31.7%; metabolic disease and viral hepatitis, 26.1%; tumor, 22.2%; cholestatic disease, 17.8% and vascular disease, 2.8%. Body Mass Index equal to or greater than 30 kg / m² occurred 3.9%. The average score for the Model for End-Stage Liver Disease was 23, and the mean serum creatinine was 1.35mg / dl. Regarding donors, the average age was 37.6 years, with 39.4% being female. The causes of brain death were stroke in 86 (47.8%), head injury in 77 (42.8%), and for other causes in 17 (9.4%). Aspartate aminotransferase was, on average, 77.20 UI/L. Alanine aminotransferase was, on average, 60.42 UI/L. Serum sodium > 160 mmol/l occurred in 18.6%, and the mean Gamaglutamiltransferase was 77 IU / L. The average Donor Risk Index was 1.476. As for the graft, it was found that its origin was local in 37.8%; regional, in 56.7%; and national, in 5.5% of cases. The cold ischemia time (> 10 hours) occurred in 58 (32.2%), the warm ischemia time (> 60 minutes) occurred in 14 (9.9%) of the transplants. The average time of the recipient's surgery was 6.1 hours, who received 4 U of platelets on average. 5 (2.8%) received fresh frozen plasma > 30 U. The average Balance of risk was 10. The normal clinical evolution occurred in 66 (36.7%) of the patients. Early graft dysfunction occurred in 104 (57.8%), and primary non-function in 10 (5.5%). The risk factors for early graft dysfunction were the female donor, the graft warm ischemia time greater than 60 minutes, and the11 consumption of fresh frozen plasma > 30 U by the recipient. The risk factor for primary nonfunction was the volume of platelets consumed by the recipient. The control of these risk factors contributes to the adequate function of the liver after transplantation and to improve grafts and patient's survival

A simple scoring model for predicting early graft failure and postoperative mortality after liver transplantation.

INTRODUCTION AND OBJECTIVES: Graft failure and postoperative mortality are the most serious complications after liver transplantation. The aim of this study is to establish a prognostic scoring system to predict graft and patient survival based on serum transaminases levels that are routinely used during the postoperative period in human cadaveric liver transplants. PATIENTS AND METHODS: Postoperative graft failure and patient mortality after liver transplant were analyzed from a consecutive series of 1299 patients undergoing cadaveric liver transplantation. This was correlated with serum liver function tests and the rate of reduction in transaminase levels over the first postoperative week. A cut-off transaminase level correlating with graft and patient survival was calculated and incorporated into a scoring system. RESULTS: Aspartate-aminotransferase (AST) on postoperative day one showed significant correlation with early graft failure for levels above 723U/dl and early postoperative mortality for levels above 750U/dl. AST reduction rate (day 1 to 3) greater than 1.8 correlated with reduced graft failure and greater than 2 with mortality. Alanine-aminotransferase (ALT) reduction in the first 48h post transplantation also correlated with outcomes. CONCLUSION: A scoring system with these three variables allowed us to classify our patients into three groups of risk for early graft failure and mortality.