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Cornelius JF, Sandu N, Perez-Pinzon MA, Schaller B. Treatment of acute ischemic stroke: role of ischemic tolerance in intravenous and endovascular therapies. Expert Rev Cardiovasc Ther 2014; 7:331-2. [DOI: 10.1586/erc.09.18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Simões EA, Cardoso PFG, Pêgo-Fernandes PM, Canzian M, Pazetti R, Braga KADO, Nepomuceno NA, Jatene FB. An experimental rat model of ex vivo lung perfusion for the assessment of lungs regarding histopathological findings and apoptosis: low-potassium dextran vs. histidine-tryptophan-ketoglutarate. J Bras Pneumol 2013; 38:461-9. [PMID: 22964930 DOI: 10.1590/s1806-37132012000400008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 06/05/2012] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To compare histopathological findings and the degree of apoptosis among rat lungs preserved with low-potassium dextran (LPD) solution, histidine-tryptophan-ketoglutarate (HTK) solution, or normal saline (NS) at two ischemia periods (6 h and 12 h) using an experimental rat model of ex vivo lung perfusion. METHODS Sixty Wistar rats were anesthetized, randomized, and submitted to antegrade perfusion via pulmonary artery with one of the preservation solutions. Following en bloc extraction, the heart-lung blocks were preserved for 6 h or 12 h at 4 ºC and then reperfused with homologous blood for 60 min in an ex vivo lung perfusion system. At the end of the reperfusion, fragments of the middle lobe were extracted and processed for histopathological examination. The parameters evaluated were congestion, alveolar edema, alveolar hemorrhage, inflammatory infiltrate, and interstitial infiltrate. The degree of apoptosis was assessed using the TdT-mediated dUTP nick end labeling method. RESULTS The histopathological examination showed that all of the lungs preserved with NS presented alveolar edema after 12 h of ischemia. There were no statistically significant differences among the groups in terms of the degree of apoptosis. CONCLUSIONS In this study, the histopathological and apoptosis findings were similar with the use of either LPD or HTK solutions, whereas the occurrence of edema was significantly more common with the use of NS.
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Munneke AJ, Rakhorst G, Petersen AH, van Oeveren W, Prop J, Erasmus ME. Flush at room temperature followed by storage on ice creates the best lung graft preservation in rats. Transpl Int 2013; 26:751-60. [DOI: 10.1111/tri.12113] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 11/27/2012] [Accepted: 04/11/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Anita J. Munneke
- Department of Biomedical Engineering; UMCG; University of Groningen; Groningen; The Netherlands
| | - Gerhard Rakhorst
- Department of Surgery; UMCG; University of Groningen; Groningen; The Netherlands
| | - Arjen H. Petersen
- Department of Medical Biology section Pathology and Laboratory Medicine; UMCG; University of Groningen; Groningen; The Netherlands
| | - Wim van Oeveren
- Thorax Center University Medical Center Groningen; Groningen; The Netherlands
| | - Jochum Prop
- Department of Medical Biology section Pathology and Laboratory Medicine; UMCG; University of Groningen; Groningen; The Netherlands
| | - Michiel E. Erasmus
- Thorax Center University Medical Center Groningen; Groningen; The Netherlands
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Cardoso PFG, Pazetti R, Moriya HT, Pêgo-Fernandes PM, Almeida FMD, Correia AT, Fechini K, Jatene FB. An experimental rat model of ex vivo lung perfusion for the assessment of lungs after prostacyclin administration: inhaled versus parenteral routes. J Bras Pneumol 2012; 37:589-97. [PMID: 22042390 DOI: 10.1590/s1806-37132011000500005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 07/29/2011] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To present a model of prostaglandin I2 (PGI2) administration (inhaled vs. parenteral) and to assess the functional performance of the lungs in an ex vivo lung perfusion system. METHODS Forty Wistar rats were anesthetized and placed on mechanical ventilation followed by median sterno-laparotomy and anticoagulation. The main pulmonary artery was cannulated. All animals were maintained on mechanical ventilation and were randomized into four groups (10 rats/group): inhaled saline (IS); parenteral saline (PS); inhaled PGI2 (IPGI2); and parenteral PGI2 (PPGI2). The dose of PGI2 used in the IPGI2 and PPGI2 groups was 20 and 10 µg/kg, respectively. The heart-lung blocks were submitted to antegrade perfusion with a low potassium and dextran solution via the pulmonary artery, followed by en bloc extraction and storage at 4ºC for 6 h. The heart-lung blocks were then ventilated and perfused in an ex vivo lung perfusion system for 50 min. Respiratory mechanics, hemodynamics, and gas exchange were assessed. RESULTS Mean pulmonary artery pressure following nebulization decreased in all groups (p < 0.001), with no significant differences among the groups. During the ex vivo perfusion, respiratory mechanics did not differ among the groups, although relative oxygenation capacity decreased significantly in the IS and PS groups (p = 0.04), whereas mean pulmonary artery pressure increased significantly in the IS group. CONCLUSIONS The experimental model of inhaled PGI2 administration during lung extraction is feasible and reliable. During reperfusion, hemodynamics and gas exchange trended toward better performance with the use of PGI2 than that with the use of saline.
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Affiliation(s)
- Paulo Francisco Guerreiro Cardoso
- Department of Cardiorespiratory Diseases, Thoracic Surgery Section, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brasil.
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Simões EA, Pêgo-Fernandes PM, Cardoso PFG, Pazetti R, Werebe E, de Oliveira Braga KA, Menezes A, Nepomuceno N, Soares PRO, Correia AT, Jatene FB. Comparing the performance of rat lungs preserved for 6 or 12 hours after perfusion with low-potassium dextran or histidine-tryptophan-ketoglutarate. Transplant Proc 2011; 43:1520-4. [PMID: 21693228 DOI: 10.1016/j.transproceed.2010.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
INTRODUCTION In lung transplantation, graft dysfunction is a frequent cause of mortality; the etiopathogenesis is related to ischemia-reperfusion injury. We sought to compare the lung performance of rats after reperfusion after presentation with 3 solutions at 2 ischemia times. METHODS We randomized 60 male Wistar rats to undergo anterograde perfusion via the pulmonary artery with low-potassium dextran (LPD), histidine-tryptophan ketoglutarate (HTK), or saline. After extraction, the heart-lung blocks were preserved in a solution at hypothermia for 6 or 12 hours before perfusion with homologous blood for 60 minutes using ex vivo system Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus). Respiratory mechanics, pulmonary weight, pulmonary artery pressure (PAP), and relative lung oxygenation capacity (ROC) measurements were obtained every 10 minutes. RESULTS Comparing tidal volume (TV), compliance, resistance, ROC, PAP, and pulmonary weight the LPD, HTK, and saline group did not differ at 6 and 12 hours. The TV was higher in the lungs with 6-hour ischemia in the LPD, HTK, and saline groups. Compliance was higher in the lungs with 6-hour ischemia in the LPD and saline groups. There were no differences in ROC values comparing lungs with 6- versus 12-hour ischemia in the LPD group. A significant difference was observed between lungs in the HTK and saline groups. Resistance was higher in the lungs with 12-hour ischemia among the LPD, HTK, and saline groups. There was a gradual weight increase in the lungs, particularly those undergoing 12-hour ischemia, despite the absence of a significant difference between groups. CONCLUSION Rat lungs perfused with LPD and HTK preservation solutions showed similar reperfusion performances in this ex-vivo perfusion model.
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Affiliation(s)
- E A Simões
- Department of Cardiopneumology, Medical School, University of São Paulo, Heart Institute, Hospital das Clínicas, São Paulo, Brazil
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Soares PRO, Braga KADO, Nepomuceno NA, Pazetti R, Correia AT, Cardoso PFG, Bisceglijatene F, Pêgo-Fernandes PM. Comparison between Perfadex and locally manufactured low-potassium dextran solution for pulmonary preservation in an ex vivo isolated lung perfusion model. Transplant Proc 2011; 43:84-8. [PMID: 21335161 DOI: 10.1016/j.transproceed.2010.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Lung transplantation, a consolidated treatment for end-stage lung disease, utilizes preservation solutions, such as low potassium dextran (LPD), to mitigate ischemia-reperfusion injury. We sought the local development of LPD solutions in an attempt to facilitate access and enhance usage. We also sought to evaluate the effectiveness of a locally manufactured LPD solution in a rat model of ex vivo lung perfusion. METHODS We randomized the following groups \?\adult of male Wistar rats (n = 25 each): Perfadex (LPD; Vitrolife, Sweden); locally manufactured LPD-glucose (LPDnac) (Farmoterapica, Brazil), and normal saline solution (SAL) with 3 ischemic times (6, 12, and 24 hours). The harvested heart-lung blocks were flushed with solution at 4°C. After storage, the blocks were connected to an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus) and reperfused with homologous blood for 60 minutes. Respiratory mechanics, pulmonary artery pressure, perfusate blood gas analysis, and lung weight were measured at 10-minute intervals. Comparisons between groups and among ischemic times were performed using analysis of variance with a 5% level of significance. RESULTS Lungs preserved for 24 hours were nonviable and therefore excluded from the analysis. Those preserved for 6 hours showed better ventilatory mechanics when compared with 12 hours. The oxygenation capacity was not different between lungs flushed with LPD or LPDnac, regardless of the ischemic time. SAL lungs showed higher PCO(2) values than the other solutions. Lung weight increased over time during perfusion; however, there were no significant differences among the tested solutions (LPD, P = .23; LPDnac, P = .41; SAL, P = .26). We concluded that the LPDnac solution results in gas exchange were comparable to the original LPD (Perfadex); however ventilatory mechanics and edema formation were better with LPD, particularly among lungs undergoing 6 hours of cold ischemia.
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Affiliation(s)
- P R O Soares
- Laboratory of Thoracic Surgery Research, Department of Cardiopneumology, InCor, Clinics Hospital, University of São Paulo, Medical School, São Paulo, Brazil
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Dreyer N, Mühlfeld C, Fehrenbach A, Pech T, von Berg S, Nagib R, Richter J, Wittwer T, Wahlers T, Ochs M. Exogenous surfactant application in a rat lung ischemia reperfusion injury model: effects on edema formation and alveolar type II cells. Respir Res 2008; 9:5. [PMID: 18205928 PMCID: PMC2265285 DOI: 10.1186/1465-9921-9-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Accepted: 01/18/2008] [Indexed: 11/23/2022] Open
Abstract
Background Prophylactic exogenous surfactant therapy is a promising way to attenuate the ischemia and reperfusion (I/R) injury associated with lung transplantation and thereby to decrease the clinical occurrence of acute lung injury and acute respiratory distress syndrome. However, there is little information on the mode by which exogenous surfactant attenuates I/R injury of the lung. We hypothesized that exogenous surfactant may act by limiting pulmonary edema formation and by enhancing alveolar type II cell and lamellar body preservation. Therefore, we investigated the effect of exogenous surfactant therapy on the formation of pulmonary edema in different lung compartments and on the ultrastructure of the surfactant producing alveolar epithelial type II cells. Methods Rats were randomly assigned to a control, Celsior (CE) or Celsior + surfactant (CE+S) group (n = 5 each). In both Celsior groups, the lungs were flush-perfused with Celsior and subsequently exposed to 4 h of extracorporeal ischemia at 4°C and 50 min of reperfusion at 37°C. The CE+S group received an intratracheal bolus of a modified natural bovine surfactant at a dosage of 50 mg/kg body weight before flush perfusion. After reperfusion (Celsior groups) or immediately after sacrifice (Control), the lungs were fixed by vascular perfusion and processed for light and electron microscopy. Stereology was used to quantify edematous changes as well as alterations of the alveolar epithelial type II cells. Results Surfactant treatment decreased the intraalveolar edema formation (mean (coefficient of variation): CE: 160 mm3 (0.61) vs. CE+S: 4 mm3 (0.75); p < 0.05) and the development of atelectases (CE: 342 mm3 (0.90) vs. CE+S: 0 mm3; p < 0.05) but led to a higher degree of peribronchovascular edema (CE: 89 mm3 (0.39) vs. CE+S: 268 mm3 (0.43); p < 0.05). Alveolar type II cells were similarly swollen in CE (423 μm3(0.10)) and CE+S (481 μm3(0.10)) compared with controls (323 μm3(0.07); p < 0.05 vs. CE and CE+S). The number of lamellar bodies was increased and the mean lamellar body volume was decreased in both CE groups compared with the control group (p < 0.05). Conclusion Intratracheal surfactant application before I/R significantly reduces the intraalveolar edema formation and development of atelectases but leads to an increased development of peribronchovascular edema. Morphological changes of alveolar type II cells due to I/R are not affected by surfactant treatment. The beneficial effects of exogenous surfactant therapy are related to the intraalveolar activity of the exogenous surfactant.
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Affiliation(s)
- Niels Dreyer
- Department of Anatomy, Division of Electron Microscopy, University of Göttingen, Kreuzbergring 36, D-37075 Göttingen, Germany.
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Wittwer T, Franke UFW, Fehrenbach A, Ochs M, Sandhaus T, Schuette A, Richter S, Dreyer N, Knudsen L, Müller T, Schubert H, Richter J, Wahlers T. Experimental Lung Transplantation: Impact of Preservation Solution and Route of Delivery. J Heart Lung Transplant 2005; 24:1081-90. [PMID: 16102444 DOI: 10.1016/j.healun.2004.07.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 07/15/2004] [Accepted: 07/19/2004] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND Optimal preservation of allograft integrity is essential to reduce post-ischemic organ dysfunction after lung transplantation. Retrograde organ preservation leads to homogeneous intrapulmonary distribution and eliminates intravascular thrombi. So far, no comparative studies exist with regard to preservation quality following retrograde preservation with Perfadex and Celsior after extended cold-ischemia intervals. METHODS In an in vivo pig model, 5 lungs each were preserved for 27 hours using antegrade or retrograde perfusion techniques with Celsior (Ce(ant)/CE(ret)) and Perfadex (PER(ant)/PER(ret)). After left lung transplantation and contralateral lung exclusion, hemodynamics, oxygenation and dynamic compliance were monitored for 6 hours and compared with sham-operated controls. Pulmonary edema was determined stereologically. Statistics consisted of analysis of variance (ANOVA) with repeated measures. RESULTS Mortality of all Celsior-protected lungs was 100% due to severe reperfusion injury with profound lung edema. In contrast, organ preservation with PER(ant) led to sufficient graft function without mortality. Preservation quality after retrograde administration of Perfadex resulted in optimized oxygenation capacity compared with PER(ant) (p = 0.046). Furthermore, intra-alveolar edema was reduced and generally comparable with sham controls. In general, retrograde preservation led to continuous washout of small blood and fibrin clots from the pulmonary capillary system. CONCLUSIONS Perfadex solution provided sufficient lung preservation for 27 hours of cold ischemia, and its retrograde application led to significant functional and histologic improvement compared with antegrade perfusion. In contrast, preservation with Celsior solution resulted in lethal post-ischemic outcome, regardless of the route of administration, and therefore must be considered unsuitable for extended lung procurement.
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Affiliation(s)
- Thorsten Wittwer
- Department of Cardiothoracic and Vascular Surgery, Friedrich-Schiller University, Jena, Germany.
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Wittwer T, Franke U, Fehrenbach A, Meyer D, Sandhaus T, Pfeifer F, Dreyer N, Mueller T, Schubert H, Richter J, Wahlers T. Impact of retrograde graft preservation in perfadex-based experimental lung transplantation. J Surg Res 2004; 117:239-48. [PMID: 15047129 DOI: 10.1016/j.jss.2003.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2003] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Optimal preservation of postischemic organ function is a continuing challenge in clinical lung transplantation. Retrograde instillation of preservation solutions has theoretical advantages to achieve a homogeneous distribution in the lung due to perfusion of both the pulmonary and the bronchial circulation. Thus far, no systematic screening studies followed by in vivo large animal reevaluation including stereological analysis of intrapulmonary edema exist concerning the influence of retrograde preservation on postischemic lung function after preservation with low potassium dextran (LPD) solution (Perfadex). MATERIALS AND METHODS For initial screening in an extracorporeal rat model eight lungs, each, were preserved for 4 h using antegrade or retrograde preservation with LPD solution (Perfadex; PER(ant)/PER(ret)). Respiratory and hemodynamic results after reperfusion were compared to low-potassium Euro-Collins (LPEC). For systematic reevaluation, five pig lungs, each, were preserved correspondingly for 27 h, and results were compared to sham-operated control lungs. In both models, edema formation was quantified stereologically. Statistics comprised different ANOVA models. RESULTS In both models, use of PER(ret) resulted in significantly higher oxygenation capacity, lower inspiratory pressures, and lower amounts of intraalveolar edema as compared to PER(ant). Results of PER(ret) were not different from sham controls in the in vivo model; furthermore, a continuous retrograde elimination of blood clots from pulmonary microcirculation was noticed. CONCLUSIONS Retrograde application of LPD solution (Perfadex) results in significant functional and histological improvement as compared to antegrade perfusion. This innovative technique can be applied very easily in clinical practice and might be an ideal adjunct to further optimize the results after lung transplantation with LPD-based graft protection.
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Affiliation(s)
- Thorsten Wittwer
- Department of Cardiothoracic and Vascular Surgery, Friedrich-Schiller University, 07740 Jena, Germany.
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Fehrenbach A, Pufe T, Wittwer T, Nagib R, Dreyer N, Pech T, Petersen W, Fehrenbach H, Wahlers T, Richter J. Reduced vascular endothelial growth factor correlates with alveolar epithelial damage after experimental ischemia and reperfusion. J Heart Lung Transplant 2003; 22:967-78. [PMID: 12957606 DOI: 10.1016/s1053-2498(02)01157-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND After clinical lung transplantation, the amount of vascular endothelial growth factor (VEGF) was found to be decreased in the bronchoalveolar lavage from lungs with acute lung injury. Since Type II pneumocytes are a major site of VEGF synthesis, VEGF depression may be an indicator of pulmonary epithelial damage after ischemia and reperfusion. METHODS Using an established rat lung model, we investigated the relationship between VEGF protein expression, oxygenation capacity and structural integrity after extracorporeal ischemia and reperfusion (ischemia 6 hours at 10 degrees C, reperfusion 50 minutes) and preservation with either low-potassium dextran solution (Perfadex 40 kD, n = 8) or Celsior (n = 6). Untreated, non-ischemic lungs served as controls (n = 5 per group). Perfusate oxygenation was recorded during reperfusion. An enzyme-linked immunoassay (ELISA) for VEGF protein and reverse transcription-polymerase chain reaction (RT-PCR) for mRNA splice variants were determined on tissue collected from the left lungs, whereas the right lungs were fixed by vascular perfusion for VEGF immunohistochemistry as well as structural analysis by light and electron microscopy. Tissue collection by systematic uniform random sampling was representative for the whole organ and allowed for quantification of structures by stereological means. RESULTS After ischemia and reperfusion, the 3 major VEGF isoforms, VEGF(120), VEGF(164) and VEGF(188), were present. VEGF protein expression was reduced, which correlated significantly with perfusate oxygenation (r = 0.736; p = 0.002) at the end of reperfusion. It was inversely related to Type II cell volume (r = 0.600; p = 0.047). VEGF protein was localized by immunohistochemistry in Type II pneumocytes, alveolar macrophages as well as bronchial epithelium, and staining intensity of Type II cells was reduced after ischemia and reperfusion. Alveolar edema did not occur but significant interstitial edema accumulated around vessels and in the blood-gas barrier, which showed a higher degree of epithelial damage after preservation with Celsior compared with the other groups. CONCLUSIONS Depression in VEGF protein expression can be considered an indicator for increased alveolar epithelial damage. Preservation with low-potassium dextran solution resulted in improved oxygenation and tissue integrity compared with Celsior.
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Affiliation(s)
- Antonia Fehrenbach
- Division of Electron Microscopy, Center of Anatomy, University of Göttingen, Göttingen, Germany.
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Wittwer T, Albes JM, Fehrenbach A, Pech T, Franke UFW, Richter J, Wahlers T. Experimental lung preservation with Perfadex: effect of the NO-donor nitroglycerin on postischemic outcome. J Thorac Cardiovasc Surg 2003; 125:1208-16. [PMID: 12830037 DOI: 10.1016/s0022-5223(02)73244-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Optimal preservation of postischemic graft function is essential in lung transplantation. Antegrade flush perfusion with modified Euro-Collins solution represents the standard technique worldwide. However, growing evidence suggests the superiority of extracellular-type Perfadex solution (Vitrolife AB, Gothenburg, Germany) over Euro-Collins solution. During ischemia and reperfusion, endogenous pulmonary nitric oxide synthesis is decreased, and therefore therapeutic stimulation of the nitric oxide pathway might be beneficial in ameliorating ischemia-reperfusion damage. However, research mainly focuses on nitric oxide supplementation of intracellular solutions, and no studies exist in which the effect of nitroglycerin on Perfadex preservation quality is evaluated. METHODS Eight rat lungs each were preserved with Perfadex solution with or without nitroglycerin (0.1 mg/mL) and compared with low-potassium Euro-Collins solution. Postischemic lungs were reventilated and reperfused, and oxygenation capacity, pulmonary vascular resistance, and peak inspiratory pressures were monitored continuously. Stereological analysis was used for evaluation of pulmonary edema and assessment of the vasculature. Statistics were performed by using different analysis of variance models. RESULTS The oxygenation capacity of the Perfadex-preserved groups was higher compared with that of the low-potassium Euro-Collins solution group (P <.03). By using nitroglycerin, flush-perfusion time was reduced, and Perfadex solution with nitroglycerin-protected lungs showed superior oxygenation capacity compared with that seen in Perfadex solution-protected organs (P <.01). Furthermore, pulmonary vascular resistance and peak inspiratory pressures were improved in the nitroglycerin group (P <.01). Stereology revealed comparable intrapulmonary edema between groups and a trend toward less vasoconstricted vasculature in Perfadex with nitroglycerin-protected lungs. CONCLUSIONS Perfadex solution provides superior lung preservation in terms of postischemic oxygenation capacity than Euro-Collins solution. Supplementation of the nitric oxide pathway by nitroglycerin further enhances functional outcome of Perfadex-preserved organs and might be an easily applicable tool in clinical lung transplantation.
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Affiliation(s)
- Thorsten Wittwer
- Department of Cardiothoracic and Vascular Surgery, Friedrich-Schiller University, Jena, Germany.
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de Perrot M, Liu M, Waddell TK, Keshavjee S. Ischemia-reperfusion-induced lung injury. Am J Respir Crit Care Med 2003; 167:490-511. [PMID: 12588712 DOI: 10.1164/rccm.200207-670so] [Citation(s) in RCA: 664] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ischemia-reperfusion-induced lung injury is characterized by nonspecific alveolar damage, lung edema, and hypoxemia occurring within 72 hours after lung transplantation. The most severe form may lead to primary graft failure and remains a significant cause of morbidity and mortality after lung transplantation. Over the past decade, better understanding of the mechanisms of ischemia-reperfusion injury, improvements in the technique of lung preservation, and the development of a new preservation solution specifically for the lung have been associated with a reduction in the incidence of primary graft failure from approximately 30 to 15% or less. Several strategies have also been introduced into clinical practice for the prevention and treatment of ischemia-reperfusion-induced lung injury with various degrees of success. However, only three randomized, double-blinded, placebo-controlled trials on ischemia-reperfusion-induced lung injury have been reported in the literature. In the future, the development of new agents and their application in prospective clinical trials are to be expected to prevent the occurrence of this potentially devastating complication and to further improve the success of lung transplantation.
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Affiliation(s)
- Marc de Perrot
- Toronto Lung Transplant Program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
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Brandes H, Albes JM, Conzelmann A, Wehrmann M, Ziemer G. Comparison of pulsatile and nonpulsatile perfusion of the lung in an extracorporeal large animal model. Eur Surg Res 2002; 34:321-9. [PMID: 12145559 DOI: 10.1159/000063067] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Extracorporeal lung-perfusion models are widely used to evaluate pulmonary preservation techniques and reperfusion injury. However, these models mainly depend on nonpulsatile flow, which is not physiological and can subsequently lead to pulmonary edema. Observation in a standardized setting and reliability of functional and structural data assessment are therefore limited. To overcome these limitations we developed a new extracorporeal large animal lung perfusion model utilizing pulsatile flow to perfuse the pulmonary vasculature. METHODS Lungs of juvenile domestic pigs were in situ preserved with 2 liters Perfadex and stored for 3 h at 10 degrees C. Thereafter, reperfusion of the lung was performed in an extracorporeal blood perfusion circuit employing either a modified roller pump with pulsatile module (300 ml/min; pulsation rate 90/min) or a standardized roller pump with continuous flow (30 ml/min). Ventilation was performed with physiologic room air (350 ml; 16/min) for 1 h. Pulsatile and nonpulsatile perfusion was performed in 2 groups (group NP: nonpulsatile; group P: pulsatile flow, n = 7) during reperfusion. Peak inspiratory pressure (PIP), mean pulmonary artery pressure (PAP), and oxygenation capacity (DeltaPO(2)) were continuously measured. For control of the effectiveness of the pulsatile perfusion pressure waveforms were obtained directly from the native pulmonary artery of both groups. Malondialdehyde (MDA) as a parameter for lipid peroxidation and endothelial cell damage was assessed at 10, 30 and 50 min reperfusion. At the end of the study, pulmonary water content was assessed by means of wet-to-dry ratio (W/D ratio). The tissue was further processed for microscopic analysis. RESULTS PIP increased significantly in both groups during reperfusion. Mean PAP in both groups increased to 60 mm Hg after 20 min followed by a decrease after 60 min to 40 mm Hg. Pressure waveforms of the pulmonary artery showed sufficient pulsatility in the pulmonary vasculature with a systolic/diastolic pressure difference of 15 mm Hg whereas the pressure difference was 3-5 mm Hg in the nonpulsatile group. DeltaPO(2) was stable in groups NP and P during reperfusion (30 min: NP: 66.4 (62.2-88) mm Hg; P: 74.8 (65-81.7) mm Hg) without any statistically significant differences between the groups. MDA in group NP decreased over the reperfusion period from 6.2 (3.3-6.3) microM at 10 min to 5.2 (3.2-6.1) microM at 50 min, whereas in group P the level increased and was significantly higher after 50 min reperfusion compared to group NP [6.6 (6.1-9.2) microM at 50 min; p = 0.016]. W/D ratio was 6.7 (6.3-7.0) in group NP and 6.8 (6.3-7.6) in group P. Light microscopy evaluation showed no differences between both groups regarding severity of intra-alveolar and interstitial edema and numbers of intra-alveolar, intracapillary and interstitial granulocytes. CONCLUSION Although effective pulsatile perfusion of the pulmonary vasculature was achieved by means of a modified roller pump, this measure obviously did not improve functional parameters nor did it significantly reduce the edema formation after 3 h ischemia in this extracorporeal lung perfusion model. The use of pulsatile perfusion is therefore not mandatory in the extracorporeal setting of a large animal lung perfusion model.
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Affiliation(s)
- H Brandes
- Department of Cardiothoracic and Vascular Surgery, University Hospital Jena, Germany.
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Brandes H, Albes JM, Haas B, Ziemer G. Influence of high molecular dextrans on lung function in an ex vivo porcine lung model. J Surg Res 2001; 101:225-31. [PMID: 11808501 DOI: 10.1006/jsre.2001.6287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Extracellular preservation solutions utilizing high molecular agents can reduce intracellular edema during ischemia/reperfusion in lung transplantation. A solution of 40,000 dalton molecular weight (DMW) has already been clinically established (Perfadex). However, it is unclear whether dextrans of this particular size represent the optimal additive for lung preservation solutions. MATERIALS AND METHODS In a new ex vivo porcine lung model, lungs were each preserved with low-potassium solutions containing 5% dextran with 90,000 DMW (Dex 90) and 160,000 DMW (Dex 160) and with Perfadex (40,000 DMW). After 24 h of cold ischemia, reperfusion was performed employing a roller pump with a pulsatile module. Lungs were perfused with deoxygenated perfusate and ventilated with room air. The oxygenation capacity (Delta pO(2)), peak inspiratory pressure (PIP), and mean pulmonary artery pressure (PAP) were monitored for 60 min. Net weight gain (NWG) and wet-to-dry ratio (W/D ratio) were determined. Free-radical generation was assessed by measuring malondialdehyde (MDA) at 10, 30, and 50 min. RESULTS PIP and PAP increased in all groups significantly during reperfusion. However, Dex 160-perfused lungs exhibited significantly higher values than those with Dex 90 and Perfadex. Perfadex showed the highest Delta pO(2) throughout the entire reperfusion, while Delta pO(2) was slightly reduced in Dex 160 and significantly lower in Dex 90. In Perfadex the lowest water content was observed assessed by NWG and W/D ratio. The highest MDA values were observed in Dex 90, followed by Dex 160, while the lowest values were seen in Perfadex. CONCLUSIONS Preservation of the lung with Perfadex exhibited superior postischemic function in contrast to preservation solutions containing dextrans with a higher molecular weight.
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Affiliation(s)
- H Brandes
- Department of Cardiac, Thoracic, and Vascular Surgery, University Hospital Jena, Germany.
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Fehrenbach A, Fehrenbach H, Wittwer T, Ochs M, Wahlers T, Richter J. Evaluation of pulmonary edema: stereological versus gravimetrical analysis. Eur Surg Res 2001; 33:270-8. [PMID: 11684833 DOI: 10.1159/000049717] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Assessment of lung edema by gravimetrical analysis is a standard method to evaluate the severity of experimentally induced ischemia/reperfusion (IR) injury. The aim of this study was to compare gravimetrical assessment of pulmonary edema with a stereological approach which allows for qualitative and quantitative distinction between intravascular and edematous fluids by light microscopy. Eight experimental groups which differed in mode of preservation, ischemic storage and pharmacological treatments were studied in an extracorporeal rat lung model. Analysis of the pooled data showed that the wet/dry ratio values mainly reflected the amount of intra-alveolar edema (r(s) = 0.442; p = 0.0057) but only stereological assessment of edema formation revealed differences depending on the treatment used. Only stereological data correlated significantly with oxygen tension measured at the end of reperfusion (r(s) = -0.530; p = 0.0009). We conclude that gravimetry is of minor functional importance compared to assessment by stereological methods which prove to be a reliable and efficient tool for the evaluation of IR injury in the different experimental settings.
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Affiliation(s)
- A Fehrenbach
- Division of Electron Microscopy, Center of Anatomy, University of Göttingen, Germany.
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Wittwer T, Fehrenbach A, Meyer D, Brandes H, Albes J, Richter J, Wahlers T. Retrograde flush perfusion with low-potassium solutions for improvement of experimental pulmonary preservation. J Heart Lung Transplant 2000; 19:976-83. [PMID: 11044693 DOI: 10.1016/s1053-2498(00)00189-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND Optimal preservation of post-ischemic organ function is a continuing challenge in clinical lung transplantation. Retrograde instillation of preservation solutions has the theoretic advantage of achieving homogeneous distribution in the lung because of perfusing both the pulmonary and the bronchial circulation. So far, we have seen no experimental studies that include stereologic analysis of intrapulmonary edema concerning the influence of retrograde preservation on post-ischemic lung function after preservation with Perfadex and Celsior. METHODS In an extracorporeal rat model, we perfused 8 lungs, each, using either antegrade or retrograde perfusion technique with Celsior (CE(ant)/CE(ret)) and Perfadex (PER(ant)/PER(ret)). Results were compared with low-potassium Euro-Collins. Post-ischemic lungs were reventilated and reperfused mechanically. We continuously monitored relative oxygenation capacity (ROC), pulmonary artery pressure, flush time, and wet/dry ratio. Furthermore, we used stereologic means to evaluate edema formation. Statistics comprised different analysis of variance models. RESULTS Relative oxygen capacity of CE(ant)-protected lungs was superior to that of PER(ant) preservation (p = 0.05). Use of PER(ret) resulted in significantly higher ROC as compared with PER(ant) (p < 0.001) and was comparable to results obtained with CE-preservation, which was not further improved with retrograde application. CONCLUSIONS Celsior provides better lung preservation than does Perfadex when administered antegradely. Retrograde application of Perfadex results in significant functional improvement as compared with antegrade perfusion, which reaches the standard of Celsior-protected organs. Additional in vivo experiments in combination with ultrastructural analysis are warranted to further evaluate retrograde delivery of preservation solutions, which could be used in clinical lung transplantation to further optimize current results.
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Affiliation(s)
- T Wittwer
- Department of Cardiac Surgery, Thoracic and Vascular Surgery, Friedrich-Schiller University, Jena, Germany.
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Fehrenbach A, Ochs M, Warnecke T, Wahlers T, Wittwer T, Schmiedl A, Elki S, Meyer D, Richter J, Fehrenbach H. Beneficial effect of lung preservation is related to ultrastructural integrity of tubular myelin after experimental ischemia and reperfusion. Am J Respir Crit Care Med 2000; 161:2058-65. [PMID: 10852788 DOI: 10.1164/ajrccm.161.6.9908014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ischemia/reperfusion (I/R) injury results in the impairment of surfactant activity. The hypothesis that the differences in lung preservation quality obtained by EuroCollins (EC) and Celsior (CE) solutions were related to surfactant alterations was tested. To avoid extensive structural damage and edema formation, which can secondarily affect the surfactant system, lungs were stored for a short ischemic period (2 h at 10 degrees C) and reperfused (50 min) in an isolated perfused rat lung model after preservation with either potassium-reduced (40 mmol) EC40 or with CE. Using a modified stereological approach ultrastructure, total amount and distribution of phospholipid membranes composing tubular myelin (tm) and small (s) and large (l) unilameliar vesicles (ul) were investigated in the organ in lungs fixed by vascular perfusion either in situ (controls) or after I/R (n = 5 per group). The total amount of intraalveolar surfactant was increased after I/R. However, a significant amount (p = 0.008) of tm was displaced into the alveolar lumen and showed wider meshes of the tm lattices than did the controls (p = 0.023) where almost all tm was epithelial. In lungs preserved with EC40, epithelial tm was significantly reduced (p = 0.018), resulting in a higher ratio (p = 0.034) of surface-inactive small ul (0.05 to 0.3 microm) to surface-active epithelial tm. In the CE group approximately 50% of the total tm pool was epithelial. This was accompanied by higher parenchymal air space and improved functional parameters. Epithelial and endothelial cell-specific immunostaining did not reveal any gross damage of the blood-gas barrier. In summary, improved lung function during reperfusion was associated with beneficial effects of lung preservation on tm integrity after I/R. These observations suggest that preservation solutions ameliorate events leading to surfactant disturbance even before extensive lung injury is manifested.
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Affiliation(s)
- A Fehrenbach
- Division of Electron Microscopy, Center of Anatomy, University of Göttingen, Göttingen, Germany.
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Wittwer T, Wahlers T, Fehrenbach A, Elki S, Haverich A. Improvement of pulmonary preservation with Celsior and Perfadex: impact of storage time on early post-ischemic lung function. J Heart Lung Transplant 1999; 18:1198-201. [PMID: 10612378 DOI: 10.1016/s1053-2498(99)00088-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Optimal preservation of post-ischemic organ function is a continuing challenge in clinical lung transplantation. METHODS Using an established extracorporeal rat lung screening model, the results after preservation of 8 lungs, each with the extracellular-type preservation solutions Celsior and Perfadex using ischemic periods of 2 and 4 hours were compared to the results obtained after 2 hours of preservation with low-potassium Euro-Collins with prostacyclin. RESULTS Oxygenation capacity of all Celsior-preserved organs was significantly higher as compared to LPEC lungs (p < 0.01), and after 4 hours of ischemia, lung preservation in terms of post-ischemic oxygenation ability was significantly higher in the Celsior group compared with Perfadex-protected organs (p < 0.01). CONCLUSION Especially at extended ischemic times Celsior can provide significantly better pulmonary preservation in terms of oxygenation capacity compared to Perfadex solution, which is associated with a post-ischemic lung function only comparable to preservation with modified Euro-Collins solution.
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Affiliation(s)
- T Wittwer
- Department of Cardiothoracic and Vascular Surgery, Hannover Medical School, Germany.
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