Perfusion Technology Research Articles

Kidney perfusion: some like it hot others prefer to keep it cool.

Machine perfusion technologies provide an opportunity for improved preservation, organ assessment, and resuscitation of damaged kidneys. This review summarizes the recent advances in hypothermic and normothermic kidney machine perfusion technologies. Modifications to the perfusion conditions with the addition of oxygen during hypothermic machine perfusion can support a low level of metabolism, which in experimental settings improves graft function. Normothermic machine perfusion technologies are evolving in different directions including short-duration resuscitation, more prolonged periods of perfusion, and the transition between hypothermic and normothermic conditions. Clinical trials are ongoing in both hypothermic and normothermic settings. Functional parameters can be used to assess kidney quality and although normothermic machine perfusion may hold an advantage over hypothermic machine perfusion, new metabolomic, proteomic, and genomic technologies may be applied in the future to both technologies to provide more rigorous information on kidney quality. Promoting recovery by introducing an intervention during perfusion is an attractive area of research and therapies targeting the endothelium are a particular area of interest. A great deal of research is still needed to optimize and logistically place hypothermic and normothermic perfusion technologies. In the future, we may progress toward organ-tailored preservation whereby high-risk kidneys can undergo assessment and repair before transplantation.

Progress and challenge of Stanford type A aortic dissection in China

In recent 20 years, the rapid development of acute Stanford type A aortic dissection in China has been mainly due to three aspects: (1) the refined classification of aortic dissection based on Stanford classification, (2) right axillary artery canal and selective cerebral perfusion technology become basic cardiopulmonary bypass strategy for Stanford type A aortic dissection, and (3) total aortic arch replacement and descending aortic stent graft surgery (Sun's surgery) become the standard treatment of Stanford type A aortic dissection. However, there are still many problems in the diagnosis and treatment of aortic dissection in China, such as: (1) unstandardized, lack of comprehensive guidelines of aortic dissection, (2) immature, perioperative organ protection and intraoperative blood protection technology remains a big flaw, and (3) it takes a long time to get patient prepared for surgery. In conclusion, as to the issue of the management of acute Stanford type A aortic dissection, there will be a long way for Chinese doctors to go. Peers should pay more attention to this problem and take more efforts, so that the outcome of acute Stanford type A aortic dissection surgical patients can be improved.

Enhancing enterovirus A71 vaccine production yield by microcarrier profusion bioreactor culture

Hand, foot and mouth diseases (HFMD) are mainly caused by Enterovirus A71 (EV-A71) infections. Clinical trials in Asia conducted with formalin-inactivated EV-A71 vaccine candidates produced from serum-free Vero cell culture using either roller bottle or cell factory technology, are found to be safe and highly efficacious. To increase vaccine yields and reduce the production costs, the bioprocess improvement for EV-A71 vaccine manufacturing is currently being investigated. The parameters that could affect and enhance the production yields of EV-A71 virus growth in the microcarrier bioreactor were investigated. The medium replacement culture strategy included a multi-harvested semi-batch process and perfusion technology and was found to increase the production yields more than 7–14 folds. Based on the western blot and cryo-EM analyses of the EV-A71 virus particles produced from either the multi-harvested semi-batch (MHSBC) or perfusion cultures were found to be similar to those virus particles obtained from the single batch culture. Mouse immunogenicity studies indicate that the EV-A71 vaccine candidates produced from the perfusion culture have similar potency to those obtained from single batch bioprocess. The physical structures of the EV-A71 particles revealed by the cryo-EM analysis were found to be spherical capsid particles. These results provide feasible technical bioprocesses for increasing virus yields and the scale up of EV-A71 vaccine manufacturing using the bioreactor cell culture methods.

Robotic mitral valve surgery.

Mitral valve repair surgery has advanced markedly over the past 25 years with excellent long-term outcomes. And the significant advances in surgical optics, instrumentation, and perfusion technology have allowed surgeons to perform mitral valve surgery using progressively smaller incisions. Due to its excellent therapeutic results, minimally invasive mitral valve surgery has become a standard of care at quite some specialized centers worldwide. The da Vinci robotic surgical system, an embodiment of minimally invasive surgical tools, was introduced to mitral valve surgery in 1998. And Chitwood further refined the endoscopic approach, taking advantage of the da Vinci robotic surgical system and its advanced robotic technology to repair complex mitral valve pathology through port incisions using optimized, high-definition visualization and fine dexterity. The excellent clinical outcomes are built on the foundation of stepwise improvement in surgeon’s techniques with a gradual learning curve. This chapter covers robotic mitral valve repair and replacement.

Effect of congenital stationary night blindness on oxygen induced retinal neovascularization by improved Chinese ink perfusion method

Background Congenital stationary night blindness (CSNB) is a common genetic eye disease.Retinal angiogenesis is rarely obtained in retinal degeneration animal.The effects of CSNB on retinal angiogenesis require further study. Objective This study was to improve Chinese ink perfusion technology and to explore the effect of CSNB on oxygen induced neovascularization. Methods Eighteen clean 7-day old SD rats and 18 clean 7-day old CSNB rats were included, twelve SD rats and twelve CSNB rats were chosen randomly for oxygen induced retinopathy (OIR) modeling, and served as OIR group, six SD rats and six CSNB rats were chosen as normal control.Nine rats were chosen randomly from both SD rats and CSNB rats in OIR group, respectively.The rats were separated into 1∶1 ratio ink group, 2∶1 ratio ink group and conventional ink group, which were perfused with 1∶1 ratio ink perfusate, 2∶1 ratio ink perfusate and conventional ink, respectively.The unilateral eyes of the rats were prepared for whole-mount retina, the other eyes were performed for paraffin imbedding.The quality of retinal vascular imaging were compared among different ink perfusate groups.The normal control rats, three SD rats in OIR group and three CSNB rats in OIR group were perfused with 2∶1 ratio ink perfusate.Histopathology examination was performed on the paraffin section, and the number of nuclei breakthrough the inner limiting membrane were counted.Immunocytochemistry were performed on the paraffin section for detecting the expression of von Wilebrand factor (v-WF). Results Compared with 1∶1 ratio ink perfusion and conventional ink perfusion, 2∶1 ratio ink perfusion showed the full vascular net clearly.Histopathology showed that the structure of retina was normal in the normal control group, and there were no endothelial nuclei breakthrough the inner limiting membrane.A large number of endothelial nuclei breakthrough the inner limiting membrane in the OIR group, the number of endothelial nuclei breaking through the inner limiting membrane were (23.08±2.99)/slide and (41.12±9.36)/slide for SD rats and CSNB rats, respectively.The number of endothelial nuclei breakthrough inner limiting membrane was higher in the CSNB rats than that in the SD rats, with no difference between the two group(q=1.70, P=0.50). Immunocytochemistry results showed that v-WF was positive expressed in the cells breakthrough inner limiting membrane. Conclusions Improved ink perfusion method was an easy-to-use whole-mount retina method with good repeatability.Hyperoxia can induce retinal neovascularization of CSNB rats. Key words: Retinal neovascularization; Congenital stationary nigh blindness; Chinese ink perfusion; Whole-mount retina

Application of CT Perfusion Imaging Technology in the Diagnosis of Hepatitis and Liver Cirrhosis

AbstractImages obtained via computer tomography perfusion (CTP) technology, a non-invasive functional imaging method, can reflect the hemodynamic status and function of the liver. Images obtained via CTP imaging technology can be quantitatively analyzed. The fundamentals, examination, and analysis of CTP images are reviewed in this paper. In addition, this paper provides a review of normal liver CTP imaging, CTP research status, and future developments in the CTP imaging of hepatitis and liver cirrhosis.

臓器工学に向けた灌流技術のUp to Date

臓器工学に向けた灌流技術のUp to Date

Systems Pharmacology Dissection of the Protective Effect of Myricetin Against Acute Ischemia/Reperfusion-Induced Myocardial Injury in Isolated Rat Heart.

In this paper, we investigated the multi-target effect of myricetin as a therapeutic for cardiovascular disease, using an acute ischemia/reperfusion-induced myocardial injury model to gain insight into its mechanism of action. The compound-target interaction profiles of myricetin were determined using a combination of text mining, chemometric and chemogenomic methods. The effect of myricetin on cardiac function was investigated by carrying out experiments in rats subjected to ischemia/reperfusion (I/R) using Langendorff retrograde perfusion technology. Compared to the I/R group, pretreatment with 5μM myricetin was observed to improve the maximum up/down rate of left ventricular pressure (dp/dt max) and coronary flow, raise left ventricular developed pressure, and decrease creatine kinase and lactate dehydrogenase levels in coronary flow. In addition, myricetin treatment was shown to have beneficial effects through its ability to reduce both infarct size and levels of cardiomyocyte apoptosis. Myricetin was also observed to have antioxidant properties, as evidenced by its ability to reduce MDA levels, while increasing both SOD levels and the GSH/GSSG ratio. Finally, an upregulation of 6-phosphogluconate dehydrogenase and fatty acid synthase expression and a downregulation of cyclooxygenase-2, cytochrome P450 and p38 mitogen-activated protein kinase expression suggest that myricetin acts through mechanisms which alter relevant signaling pathways. In summary, our results demonstrate that myricetin has protective cardiovascular effects against I/R-induced myocardial injury.

Cardioprotection provided by Echinatin against ischemia/reperfusion in isolated rat hearts.

BackgroundThis study evaluated the protective effect of Echinatin against myocardial ischemia/reperfusion (I/R) injury in rats.MethodsThe effect of Echinatin on cardiac function in rats subjected to I/R was demonstrated through improved Langendorff retrograde perfusion technology. Adult Sprague–Dawley rats were randomly divided into five groups, and myocardial infarct size was macroscopically estimated through 2,3,5-triphenyltetrazolium chloride staining. The coronary effluent was analyzed for the release of lactate dehydrogenase (LDH) and creatine kinase (CK) to assess the degree of cardiac injury. The concentrations of malondialdehyde (MDA), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were determined along with superoxide dismutase (SOD) activity using ELISA. Finally, cardiomyocyte apoptosis analysis was conducted with POD, an in situ cell death detection kit.ResultsEchinatin (0.5 and 2.5 μg/mL) pretreatment enhanced the maximum up/down rate of the left ventricular pressure (±dp/dtmax), improved the heart rate, increased the left ventricular developed pressure (LVDP), enhanced the coronary flow, and reduced the CK and LDH levels in the coronary flow of the treated group compared with the I/R group. Echinatin limited the contents of CK and LDH, improved the LVDP, reduced the contents of MDA, IL-6, and TNF-α, and increased the SOD activity. The infarct size and cell apoptosis in the hearts of the rats in the Echinatin-treated group were smaller and lower, respectively, than those in the hearts of the rats in the I/R control group.ConclusionEchinatin exerts a protective effect against I/R-induced myocardial injury on hearts. This effect may be attributed to the antioxidant and anti-inflammatory activities of this compound.

Ex-vivo liver perfusion for organ preservation: Recent advances in the field.

Liver transplantation is the optimal treatment for end-stage liver disease but is limited by the severe shortage of donor organs. This shortage has prompted increased utilization of marginal grafts from DCD and extended criteria donors, which poorly tolerate cold storage in comparison to standard criteria grafts. Ex-vivo liver perfusion (EVLP) technology has emerged as a potential alternative to cold storage for organ preservation, but there is no consensus regarding the optimal temperature or conditions for EVLP. Herein, we review recent advances in both pre-clinical and clinical studies, organized by perfusion temperature (hypothermic, subnormothermic, normothermic).

Comparison of current practices of cardiopulmonary perfusion technology in Iran with American Society of Extracorporeal Technology's standards.

Introduction: Standards have a significant role in showing the minimum level of optimal optimum and the expected performance. Since the perfusion technology staffs play an the leading role in providing the quality services to the patients undergoing open heart surgery with cardiopulmonary bypass machine, this study aimed to assess the standards on how Iranian perfusion technology staffs evaluate and manage the patients during the cardiopulmonary bypass process and compare their practice with the recommended standards by American Society of Extracorporeal Technology. Methods: In this descriptive study, data was collected from 48 Iranian public hospitals and educational health centers through a researcher-created questionnaire. The data collection questionnaire assessed the standards which are recommended by American Society of Extracorporeal Technology. Results: Findings showed that appropriate measurements were carried out by the perfusion technology staffs to prevent the hemodilution and avoid the blood transfusion and unnecessary blood products, determine the initial dose of heparin based on one of the proposed methods, monitor the anticoagulants based on ACT measurement, and determine the additional doses of heparin during the cardiopulmonary bypass based on ACT or protamine titration. It was done only in 4.2% of hospitals and health centers. Conclusion: Current practices of cardiopulmonary perfusion technology in Iran are inappropriate based on the standards of American Society of Cardiovascular Perfusion. This represents the necessity of authorities’ attention to the validation programs and development of the caring standards on one hand and continuous assessment of using these standards on the other hand.

Protective Effects of Polyphenol Extracts from Sea Buckthorn (<i>Hippopha&#235 rhamnoides</i> L.) on Rat Hearts

The objective of present study was to investigate the antioxidative and cardioprotective effects of polyphenol extracts from sea buckthorn (PESB) against myocardial ischemia reperfusion injury (MIRI). PESB was analyzed using HPLC-DAD and their antioxidant activities were evaluated by measuring the intrinsic free radicals cavenging capacity and inhibiting the formation of hydroxyl radical capacity. Experiments on the isolated rat hearts were carried out according to the improved Langendorff retrograde perfusion technology. Coronary effluent of lactate dehydrogenase (LDH) and creatine kinase isoenzyme (CK-MB) activities were analyzed to determine the extent of myocardial injury. Protein expression levels of Beclin-1, microtubule-associated protein 1 light chain 3 (LC3) I and II were measured to evaluate the degree of autophagy. In conclusion, coupled results from both in vivo and in vitro experiments have confirmed that PESB has potential health implications in both prevention and amelioration of MIRI, which may be attributed to the inhibition of autophagy.

Increased Intestinal Absorption of Genistein by Coadministering Verapamil in Rats.

Combination of genistein (GT) and verapamil, a P-glycoprotein (P-gp) inhibitor, can increase GT absorption in situ perfusion technology in rat. To date, little information is yet available about the effect of verapamil on oral absorption of GT in vivo. In this study, a simple and reproducible HPLC-UV method was developed and validated for determination of total GT in rat plasma. Based on this, a pharmacokinetic experiment was designed to characterize biopharmaceutical properties of GT with or without coadministration of verapamil (10.0, 20.0, 30.0mg/kg) in rats. The coadministration of verapamil (30.0mg/kg) with GT caused a significant increase of the maximum GT plasma concentration (1.31-fold vs. GT, P<0.05) and area under the curve (1.39-fold vs. GT, P<0.05). Our data show that verapamil would increase intestinal absorption of GT in rat, suggesting there is some drug-nutrition interaction between verapamil and GT.

Who is the Bad Guy in Perfusion Technologies? Priming Volume, Blood Air Interaction or Pump Type: A Prospective, Randomized Trial of Three Different Techniques

Objectives: Minimal extracorporeal circulation techniques or circuits (MECC) may reduce the side effects of conventional extracorporeal circulation (CECC). However, it is unclear how much of this reduction is caused by reducing priming volume and hemodilution or by avoiding blood-air contact and dispersion of mediastinal debris into the systemic circulation.

ICG angiography predicts burn scarring within 48 h of injury in a porcine vertical progression burn model

The current standard of care in determining the need to excise and graft a burn remains with the burn surgeon, whose clinical judgment is often variable. Prior work suggests that minimally invasive perfusion technologies are useful in burn prognostication. Here we test the predictive capabilities of Laser Doppler Imaging (LDI) and indocyanine green dye (ICG) angiography in the prediction of burn scarring 28 days after injury using a previously validated porcine burn model that shows vertical progression injury. Twelve female Yorkshire swine were burned using a 2.5×2.5cm metal bar at variable temperature and application times to create distinct burn depths. Six animals (48 injuries total) each were analyzed with LDI or ICG angiography at 1, 24, 48, and 72h following injury. A linear regression was then performed correlating perfusion measurements against wound contraction at 28 days after injury. ICG angiography showed a peak linear correlate (r2) of .63 (95% CI .34 to .92) at 48h after burn. This was significantly different from the LDI linear regression (p<.05), which was measured at r2 of .20 (95% CI .02 to .39). ICG angiography linear regression was superior to LDI at all timepoints. Findings suggest that ICG angiography may have significant potential in the prediction of long-term burn outcomes.

Comparison of acceleromyography and kinemyography monitoring methods during recovery period of neuromuscular block

1Istanbul Bilim University, Dept of Anaesthesiology & Intensive Care, Istanbul, Turkey, 2Istanbul Bilim University, Perfusion Technology Education Programme, Istanbul, Turkey, 3Istanbul Bilim University, Anaesthesia Technician Education Programme, Istanbul, Turkey

Does machine perfusion decrease ischemia reperfusion injury?

In 1990's, use of machine perfusion for organ preservation has been abandoned because of improvement of preservation solutions, efficient without perfusion, easy to use and cheaper. Since the last 15 years, a renewed interest for machine perfusion emerged based on studies performed on preclinical model and seems to make consensus in case of expanded criteria donors or deceased after cardiac death donations. We present relevant studies highlighted the efficiency of preservation with hypothermic machine perfusion compared to static cold storage. Machines for organ preservation being in constant evolution, we also summarized recent developments included direct oxygenation of the perfusat. Machine perfusion technology also enables organ reconditioning during the last hours of preservation through a short period of perfusion on hypothermia, subnormothermia or normothermia. We present significant or low advantages for machine perfusion against ischemia reperfusion injuries regarding at least one primary parameter: risk of DFG, organ function or graft survival.

Assessment of Tumor Grade and Angiogenesis in Colorectal Cancer: Whole-volume Perfusion CT

The preoperative evaluation of tumor grading and angiogenesis has important clinical implications in the treatment and prognosis of patients with colorectal cancers (CRCs). The aim of the present study was to assess tumor perfusion with 256-slice computed tomography (CT) using whole-volume perfusion technology before surgery, and to investigate the differences in the perfusion parameters among tumor grades and the correlation between perfusion parameters and pathologic results in CRC. Thirty-seven patients with CRC confirmed by endoscopic pathology underwent whole-volume perfusion CT assessments with a 256-slice CT and surgery. Quantitative values for blood flow, blood volume, and time to peak were determined using commercial software. After surgery, resected specimens were analyzed immunohistochemically with CD105 antibodies for the quantification of microvessel density (MVD). The difference in CT perfusion parameters and MVD among different tumor differentiation grades was evaluated by the Student-Newman-Keuls test. The correlations between CT perfusion parameters and MVD were evaluated using the Pearson correlation analysis. The mean blood flow was significantly different among well, moderately, and poorly differentiated groups (61.17 ± 17.97, 34.80 ± 13.06, and 22.24 ± 9.31 mL/minute/100 g, respectively; P < .05). The blood volume in the well-differentiated group was significantly higher than that in the moderately differentiated group (33.96 ± 24.81 vs. 16.93 ± 5.73 mL/100 g; P = .002) and that in the poorly differentiated group (33.96 ± 24.81 vs. 18.05 ± 6.01 mL/100 g; P = .009). The time to peak in the poorly differentiated group was significantly longer than that in the well-differentiated group (27.81 ± 11.95 vs. 17.60 ± 8.53 seconds; P = .016) and that in the moderately differentiated group (27.81 ± 11.95 vs. 18.94 ± 7.47 seconds; P = .028). There was no significant difference in the MVD among well, moderately, and poorly differentiated groups (33.47 ± 14.69, 28.89 ± 11.82, and 29.89 ± 11.02, respectively; P > .05). There was no significant correlation between CT perfusion parameters and MVD (r = 0.201, 0.295, and -0.178, respectively; P = .233, .076, and .292, respectively). CT whole-volume perfusion technology has the potential to evaluate pathologic differentiation grade of CRC before surgery. However, preoperative perfusion CT parameters do not reflect the MVD of CRC.

“Resuscitation” of marginal liver allografts for transplantation with machine perfusion technology

As the rate of medically suitable donors remains relatively static worldwide, clinicians have looked to novel methods to meet the ever-growing demand of the liver transplant waiting lists worldwide. Accordingly, the transplant community has explored many strategies to offset this deficit. Advances in technology that target the ex vivo "preservation" period may help increase the donor pool by augmenting the utilization and improving the outcomes of marginal livers. Novel ex vivo techniques such as hypothermic, normothermic, and subnormothermic machine perfusion may be useful to "resuscitate" marginal organs by reducing ischemia/reperfusion injury. Moreover, other preservation techniques such as oxygen persufflation are explored as they may also have a role in improving function of "marginal" liver allografts. Currently, marginal livers are frequently discarded or can relegate the patient to early allograft dysfunction and primary non-function. Bench to bedside advances are rapidly emerging and hold promise for expanding liver transplantation access and improving outcomes.

Antioxidative and Cardioprotective Effects of Total Flavonoids Extracted from Dracocephalum moldavica L. Against Acute Ischemia/Reperfusion-Induced Myocardial Injury in Isolated Rat Heart

This study evaluates antioxidative and cardioprotective effects of total flavonoids extracted from Dracocephalum moldavica L. (DML). The total flavonoids showed remarkable scavenging effects against 1,1-diphenyl-2-picrylhydrazyl, hydroxyl and superoxide anion radicals in vitro. Compared with the ischemia/reperfusion (I/R) group as demonstrated bythe use of improved Langendorff retrograde perfusion technology, the total flavonoids (5μg/mL) pretreatment improved the heart rate and coronary flow, rised left ventricular developed pressure and decreased creatine kinase, lactate dehydrogenase levels in coronary flow. The infarct size/ischemic area at risk of DML-treated hearts was smaller than that of I/R group; the superoxide dismutase activity and glutathione/glutathione disulfide ratio increased and malondialdehyde content reduced obviously (P<0.01) in total flavonoids treatment groups. In conclusion, the total flavonoids possess obvious protective effects on myocardial I/R injury, which may be related to the improvement of myocardial oxidative stress states.