ABSTRACT
ABSTRACT Liquid perfluorocarbon (PFC) instillation has been studied experimentally as an adjuvant therapy in the preservation of lung grafts during cold ischemia. The objective of this study was to evaluate whether vaporized PFC is also protective of lung grafts at different cold ischemia times. We performed histological analysis of and measured oxidative stress in the lungs of animals that received only preservation solution with low-potassium dextran (LPD) or vaporized PFC together with LPD. We conclude that vaporized PFC reduces the production of free radicals and the number of pulmonary structural changes resulting from cold ischemia.
RESUMO O perfluorocarbono (PFC) líquido tem sido estudado experimentalmente como uma substância adjuvante na preservação de enxertos pulmonares durante o período de isquemia fria. O objetivo deste estudo foi avaliar se o PFC vaporizado (e não instilado) também atuaria como protetor de enxertos pulmonares em diferentes tempos de isquemia fria. Realizamos análise histológica e dosamos o estresse oxidativo em pulmões de animais que receberam somente uma solução de preservação com low-potassium dextran (LPD, dextrana com baixa concentração de potássio) ou PFC vaporizado associado a LPD. Concluímos que o PFC vaporizado reduziu a produção de radicais livres e provocou menor número de alterações estruturais pulmonares decorrentes do período de isquemia fria que o uso de LPD isoladamente.
Subject(s)
Humans , Organ Preservation/methods , Lung Transplantation/methods , Oxidative Stress/drug effects , Cold Ischemia/methods , Fluorocarbons/pharmacology , Lung/drug effects , Reference Values , Time Factors , Reproducibility of Results , Dextrans/pharmacology , Organ Preservation Solutions , Glucose/pharmacology , Lung/pathologyABSTRACT
RESUMO Com a utilização crescente da máquina de perfusão no transplante renal, tem sido constatado que a isquemia dinâmica correlaciona-se à melhora da preservação orgânica. Nesse contexto, realizamos uma revisão sistemática que procurou avaliar a eficácia do uso de máquina de perfusão portátil (LifePort Kidney Transporter Machine®), utilizada no Brasil, comparada ao armazenamento estático, no que tange à função retardada do transplante renal de doadores com morte encefálica. Foi efetuada pesquisa bibliográfica, nas bases LILACS, MEDLINE via PubMed, Scopus, Clarivate Analytics, Cochrane Library, Embase, SciELO, além de busca manual no Google acadêmico. A revisão sistemática, finalizada em abril 2017, foi constituída somente por ensaios clínicos randomizados. Para metanálise, foram avaliadas Razão de Risco e Razão de Chance. Foram identificados 86 documentos e selecionados, ao final, dois artigos com critérios de elegibilidade para metanálise, de grupos europeus e brasileiros. Nestes, 374 rins foram alocados para a máquina de perfusão, e igual número para o armazenamento estático. A função retardada do enxerto foi constatada em 84 e 110 pacientes, respectivamente. Na metanálise, foram obtidas uma Razão de Risco de 0,7568 (p=0,0151) e uma Razão de Chance de 0,6665 (p=0,0225), ambas com intervalo de confiança de 95%. A máquina de perfusão reduziu a incidência de função retardada do enxerto de doadores com morte encefálica.
ABSTRACT With the increasing use of machine perfusion in kidney transplantation, it has been observed that dynamic ischemia correlates with the improvement of organ preservation. In this context, we performed a systematic review that aimed to evaluate the efficacy of the portable machine perfusion (LifePort Kidney Transporter Machine®), used in Brazil, compared to cold storage, regarding the delayed graft function of deceased donors with brain death. Literature search was carried out in LILACS, MEDLINE via PubMed, Scopus, Clarivate Analytics, Cochrane Library, Embase, and SciELO, as well as in Google Scholar manually. The systematic review consisted only of randomized clinical trials. For meta-analysis, relative risk and odds ratio were evaluated. Eighty-six documents were identified and two papers from European and Brazilian groups were selected at the end, with eligibility criteria for meta-analysis. In these, 374 kidneys were assigned to machine perfusion and 374 kidneys were assigned to cold storage. Delayed graft function was observed in 84 and 110 patients, respectively. In meta-analysis, a risk ratio of 0.7568 (p=0.0151) and an odds ratio of 0.6665 (p=0.0225) were obtained, both with a 95% confidence interval. Machine perfusion reduced the incidence of delayed graft function of deceased donors with brain death.
Subject(s)
Humans , Organ Preservation/methods , Perfusion/methods , Brain Death , Cold Ischemia/methods , Kidney , Organ Preservation/instrumentation , Perfusion/instrumentation , Time Factors , Pulsatile Flow , Reproducibility of Results , Risk Factors , Kidney Transplantation/methods , Delayed Graft FunctionABSTRACT
ABSTRACT Purpose The percentage of parenchyma preserved plays a predominant role in predicting renal function after partial nephrectomy (PN). Currently there is no standard method to estimate preserved renal parenchyma. In this study we propose a formula of the percentage of resected and ischemic volume (PRAIV) determined by a geometric model and evaluate the relationships between renal functional change and PRAIV as well as other clinical parameters. Materials and Methods We identified 71 patients who underwent open PN between January 2004 and April 2014. Assuming the kidney to be an ellipsoid with bilaterally equal volume and tumor to be a sphere, we calculated PRAIV by integral calculus. Nadir estimated glomerular filtration rate (eGFR) between postoperative 3 and 12 months were recorded. The correlation between percent eGFR reduction, PRAIV, and other clinical parameters were examined. Results On univariate analysis, age (p=0.03), depth of tumor invasion (p=0.004), C index (p=0.003), RAIV (p=0.04), and PRAIV (p<0.001) were correlated with percent reduction of eGFR. However, only age (p=0.007) and PRAIV (p<0.001) were significantly correlated with percent reduction of eGFR on multivariate analysis. Depicting these values along the regression line, we found R2 was 0.194 and 0.073 for PRAIV and age, respectively. Conclusions PRAIV determined by a geometric model is a significant predictor of renal functional change after PN. Using PRAIV, we can estimate percent eGFR reduction preoperatively for better patient consultation and surgical planning.
Subject(s)
Humans , Male , Female , Adult , Aged , Aged, 80 and over , Carcinoma, Renal Cell/surgery , Cold Ischemia/methods , Kidney/physiopathology , Kidney/blood supply , Kidney/pathology , Kidney Neoplasms/surgery , Nephrectomy/methods , Organ Size , Postoperative Period , Pregnanediones , Reference Values , Carcinoma, Renal Cell/physiopathology , Sex Factors , Multivariate Analysis , Reproducibility of Results , Retrospective Studies , Age Factors , Tumor Burden , Glomerular Filtration Rate , Kidney Neoplasms/physiopathology , Middle Aged , Models, TheoreticalABSTRACT
CONTEXT AND OBJECTIVE: Lung preservation remains a challenging issue for lung transplantation groups. Along with the development of ex vivo lung perfusion, a new preservation method known as topical-ECMO (extracorporal membrane oxygenation) has been proposed. The present study compared topical-ECMO with cold ischemia (CI) for lung preservation in an ex vivo experimental model. DESIGN AND SETTING: Randomized experimental study, conducted at a public medical school. METHOD: Fourteen human lungs were retrieved from seven brain-dead donors that were considered unsuitable for transplantation. The lung bloc was divided and each lung was randomized to be preserved by means of topical-ECMO or CI (4-7 °C) for eight hours. These lungs were then reconnected to an ex vivo perfusion system for functional evaluation. Lung biopsies were obtained at three times. The functional variables assessed were oxygenation capacity (OC) and pulmonary artery pressure (PAP); and the histological variables were lung injury score (LIS) and apoptotic cell count (ACC). RESULTS : The mean OC was 468 mmHg (± 81.6) in the topical-ECMO group and 455.8 (± 54) for CI (P = 0.758). The median PAP was 140 mmHg (120-160) in the topical-ECMO group and 140 mmHg (140-150) for CI (P = 0.285). The mean LIS was 35.57 (± 4.5) in the topical-ECMO group and 33.86 (± 6.1) for CI (P = 0.367). The ACC was 25.00 (± 9.34) in the topical-ECMO group and 24.86 (± 10.374) for CI (P = 0.803). CONCLUSIONS: The present study showed that topical-ECMO was not superior to cold ischemia for up to eight hours of lung preservation. .
CONTEXTO E OBJETIVO: A preservação pulmonar permanece um desafio para os grupos transplantadores. Com o desenvolvimento da perfusão pulmonar ex vivo, foi proposto um novo método de preservação chamado de ECMO-tópico (oxigenação de membrana extracorpórea). O presente estudo compara ECMO-tópico com isquemia fria (IF) para preservação pulmonar em um modelo experimental ex vivo. TIPO DE ESTUDO E LOCAL: Estudo experimental randomizado, conduzido em uma faculdade de medicina pública. MÉTODO: Quatorze pulmões humanos foram retirados de sete doadores de morte cerebral considerados não aptos a transplante. O bloco pulmonar foi dividido e cada um foi aleatorizado para preservação por ECMO-tópico ou IF (4-7 °C) durante oito horas. Esses pulmões foram então re-conectados a um sistema de perfusão ex vivo para avaliação funcional. Biópsias pulmonares foram obtidas em três tempos. As variáveis funcionais avaliadas foram: capacidade de oxigenação (CO) e pressão de artéria pulmonar (PAP). As variáveis histológicas estudadas foram escore de lesão pulmonar (ELP) e contagem de células apoptóticas (CCA). RESULTADOS: A média da CO foi de 468 mmHg (± 81.6) no grupo ECMO-tópico e 455.8 (± 54) no grupo IF (P = 0,758); a PAP média foi de 140 mmHg (120-160) para ECMO-tópico e 140 mmHg (140-150) para IF (P = 0,285); o ELP médio foi 35,57 (± 4,5) no ECMO-tópico e 33,86 (± 6,1) no IF (P = 0,367). A CCA foi 25,00 (± 9,34) no grupo ECMO-tópico e 24,86 (± 10,374) no IF (P = 0,803). CONCLUSÕES: O presente estudo demonstrou que o ECMO-tópico não é superior a IF para oito horas de preservação pulmonar. .
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Cold Ischemia/methods , Extracorporeal Membrane Oxygenation/methods , Lung , Organ Preservation/methods , Perfusion/methods , Cell Count , Medical Illustration , Organ Preservation Solutions , Reperfusion Injury , Reproducibility of Results , Statistics, Nonparametric , Time Factors , Tissue DonorsABSTRACT
OBJECTIVE: Advances in graft reepithelialization and revascularization have renewed interest in airway transplantation. This study aims to determine whether topically applied preservation solutions can ameliorate ischemic injury to tracheal grafts. We analyzed 1) the effects of cold ischemia on the mucociliary clearance of tracheal grafts and 2) the impact of topically applied preservation solutions on the effects of cold ischemia on mucociliary clearance. METHOD: Tracheal segments (n=217) from 109 male Wistar rats were harvested, submerged in low-potassium-dextran-glucose, histidine-tryptophan-ketoglutarate, or saline solution (saline group), and stored at 4°C for 6, 10, 16, or 24 hours. A control group (not submerged) was analyzed immediately after harvesting. In situ mucociliary transport and ciliary beating frequency were measured using a stroboscope. Epithelial integrity, cellular infiltration, and mucus storage were quantified by light microscopy and image analysis software, along with transmission electron microscopy. RESULTS: 1) The effects of cold ischemia: in situ mucociliary transport and ciliary beating frequency were greater in the control group than after cold ischemia. Microscopic analysis results were similar between groups. 2) The effects of preservation solutions: there was no difference between the low-potassium-dextran-glucose, histidine-tryptophan-ketoglutarate, and saline groups in functional or light microscopy analysis. The saline group presented stronger signs of ischemic injury with transmission electron microscopy. CONCLUSIONS: Cold ischemia diminished the mucociliary clearance of the tracheal respiratory epithelium. Topically applied preservation solutions did not ameliorate the injury caused by cold ischemia to the tracheal respiratory epithelium. .
Subject(s)
Animals , Male , Rats , Cold Ischemia/methods , Organ Preservation Solutions/pharmacology , Respiratory Mucosa/drug effects , Trachea/drug effects , Microscopy, Electron, Transmission , Mucociliary Clearance/drug effects , Rats, Wistar , Respiratory Mucosa/ultrastructure , Trachea/transplantation , Trachea/ultrastructureABSTRACT
PURPOSE: The aim of the study was to compare the effects of renal ice slush hypothermia and the use of trimetazidine in the protection against ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS: Fifteen farm pigs were submitted to left kidney ischemia and right nephrectomy during the same procedure. Animals were divided into three groups. Group 1 was submitted to warm ischemia; Group 2 was submitted to cold ischemia with ice slush; and Group 3 received trimetazidine 20 mg one day and 4 hours before surgery. Ischemia time was 120 minutes in all three groups. Serum creatinine (SCr) and plasma iohexol clearance (CLioh) were measured before surgery and on postoperative days (PODs) 1,3,7, and 14. Semi-quantitative analyses of histological alterations were performed by a pathologist. A p value of < 0.05 was considered significant. RESULTS: All groups showed elevation of serum creatinine in the first week. Serum creatinine was higher in Group 3 in the first and third postoperative days (Mean Cr: 5.5 and 8.1 respectively). Group 2 showed a lower increase in creatinine and a lower decrease in iohexol clearance than the others. Renal function stabilized in the fourteenth POD in all three groups. Analyses of histological alterations did not reach statistical significance between groups. CONCLUSION: Trimetazidine did not show protection against renal I/R injury in comparison to warm ischemia or hypothermia in a porcine model submitted to 120 minutes of renal ischemia.