scholarly journals 4072 Optimizing ex-vivo perfusion in Vascularized Composite Allotransplantation using Hyperosmolar solution and Electric Stimulation: Preliminary Results

2020 ◽  
Vol 4 (s1) ◽  
pp. 14-14
Author(s):  
Michael Jonczyk ◽  
Philipp Tratnig-Frankl
Keyword(s):  
Weight Gain ◽  
Muscle Biopsy ◽  
Electric Stimulation ◽  
Ex Vivo ◽  
Energy Charge ◽  
Vascularized Composite Allotransplantation ◽  
Ex Vivo Perfusion ◽  
Perfusion Model ◽  
Lactate Levels ◽  
O2 Dissociation

OBJECTIVES/GOALS: Vascularized composite allotransplantation (VCA) restores devastating soft tissue injuries. However, graft viability may be compromised during ischemia time, thus preservation techniques continue to evolve. Here we summarize our preliminary findings from preservation techniques utilizing hyperosmolar extracellular solution (HES) and electric stimulation in a 6 hour ex-vivo perfusion model. METHODS/STUDY POPULATION: A published, MGH rodent hindlimb ex-vivo perfusion model was utilized for this project. Three baseline control elements were taken to compare our results including: a baseline muscle biopsy, harvested hindlimb preserved on ice(4°C) in static cold storage (SCS), and 6 hour perfusion (SNMP) were used to compare results of our four aims. The four aims are shown in Table 1. HES was composed of muscle media and the addition of mannitol until 3 concentrations were made: 300, 500, and 800 mOsm concentrations. In aim 4, the perfusate composition was changed to test a hyper-oncotic purfusate. After 6 hours a muscle biopsy was taken to analyze energy cofactors via liquid chromatography-mass spectrometry, referred to as energy charge. Weight gain (edema), lactate levels, oxygen consumption and energy charge (EC) were used as markers for muscle tissue viability. RESULTS/ANTICIPATED RESULTS: In Aim 1, the higher osmolarity of HES indirectly reduced weight gain but consequentially reduced the EC below 5% when compared to SCS control group. We next incorporate HES into the perfusion model, Aim 2, and noticed a diminution in weight gain. The 500 mOsm group had substantial improvement in EC, lactate production and improved oxygen exchange when compared to a controls: fresh muscle biopsy and SNMP. In Aim 3, after a 6 hour perfusion with the addition of electric stimulation, graft edema improved by 10%, EC improved by 23% and O2 dissociation was highest of all 4 aims. Consequentially, due to muscular contraction the lactate levels were highest. In Aim 4, using a hyper-oncotic perfusate, edema reduced the most during the 6 hour perfusion but revealed lower EC and similar lactate/O2 results. However when left on for 24 hours, edema was significantly higher with lactate build up, EC improved with time as well as O2 dissociation. DISCUSSION/SIGNIFICANCE OF IMPACT: Here we have shown our preliminary results comparing our known ex-vivo perfusion model to multiple hypothesis to improve VCA graft viability. These preservation techniques demonstrate promising results but further studies are ongoing to confirm this encouraging outcome.

Prostanoid Release from Ex Vivo Perfused Canine Arteries and Veins: Effects of Prolonged Perfusion, Intermittent Perfusion, as well as Exposure to Exogenous Arachidonic Acid, Thrombin and Bradykinin

1989 ◽  
Vol 62 (03) ◽  
pp. 1034-1039 ◽  
Author(s):  
Jan S Brunkwall ◽  
James C Stanley ◽  
Timothy F Kresowik ◽  
Linda M Graham ◽  
William E Burkel ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Ex Vivo ◽  
Fold Increase ◽  
Ex Vivo Perfusion ◽  
Cyclooxygenase Activity ◽  
Perfusion Model ◽  
Prostanoid Production ◽  
Slow Decline ◽  
Arteries And Veins ◽  
Nonpulsatile Flow

SummaryRegulation of prostanoid release from ex vivo perfused vessel segments is not fully understood. A series of perfusion experiments were performed with canine arteries and veins to define certain regulatory phenomena. Arteries were perfused with pulsatile flow of 90 ml/min at a pressure of 100 mmHg, and veins with nonpulsatile flow of 90 ml/min at a pressure of 7 mmHg. Segments were perfused with Hanks' balanced salt solution for five 15-min periods with the perfusate exchanged after each study period. With onset of perfusion, there was an initial burst of prostacyclin release to 127 ± 40 pg/mm2, declining to 32 ± 10 pg/mm2 after 60 minutes (p <0.005). If perfusion continued for 5.5 hours, there was a stable release period between 1 and 3 hours, followed by a very slow decline. At that time addition of arachidonic acid (AA) increased prostacyclin release six-fold (p <0.01). Vessels perfused for 1 hour and then rested for another hour, responded to reperfusion at the second onset of flow with a two-fold increase in prostacyclin release (p <0.01). Vessels perfused with thrombin, bradykinin or A A (either added to each perfusate or only to the last perfusate) exhibited greater prostacyclin release than did control segments. Release of thromboxane steadily declined with time in all parts of the study, and only increased with the addition of A A to the perfusate. These data indicate that vessel segments subjected to ex vivo perfusion do not maximally utilize enzyme systems responsible for prostanoid production, and after 1 hour perfusion have not depleted their phospholipids, and maintain functioning levels of phospholipase and cyclooxygenase activity. This perfusion model allows for the study of prostacyclin and thromboxane release from arteries and veins and their response to various drugs and other stimuli.

An Ex Vivo Perfusion Model To Study the Treatment of Thrombotic Microangiopathy during Pig-to-Human Xenogenic Kidney Transplantation.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3190-3190
Author(s):  
Wolf Ramackers ◽  
Lars Friedrich ◽  
Wolfgang Schüttler ◽  
Sabine Bergmann ◽  
Arnold Ganser ◽  
...  
Keyword(s):  
Kidney Transplantation ◽  
Histological Examination ◽  
Thrombotic Microangiopathy ◽  
Flow Resistance ◽  
Ex Vivo ◽  
Autologous Blood ◽  
Human Kidney ◽  
Pharmacological Intervention ◽  
Ex Vivo Perfusion ◽  
Perfusion Model

Abstract Early rejection of xenogenic organs is associated with thrombotic microangiopathy and changes of coagulation resembling disseminated intravascular coagulation (DIC). Here, we used an ex vivo perfusion circuit as a model of pig-to-human kidney transplantation to study the nature and treatment of this pathology. Porcine kidneys were obtained following in situ cold perfusion with HTK organ preservation solution and immediately connected to a perfusion circuit containing porcine (“autologous”) or human (“xenogenic”) AB blood supplemented with complement component C1 inhibitor (1 U/ml) and heparin (1 U/ml). Perfusion of porcine kidneys with autologous blood was feasible for >240 min in all experiments. In contrast, perfusion of porcine kidneys with xenogenic human blood was limited by a dramatic increase of flow resistance after 30 to 240 min. Increased concentrations of C3a as a marker for complement activation were associated with early perfusion failure. In addition, a dramatic increase of thrombin-antithrombin complex (TAT) and D Dimer (DD) was observed together with consumption of platelets, fibrinogen and antithrombin (AT). Histological examination demonstrated extensive thrombotic microangiopathy. Supplementation recombinant human activated protein C (rhAPC, 300 ug/l*h, n=3) or recombinant human antithrombin (rhAT, 3 U/ml, n=3) abolished the increase of flow resistance and allowed for a xenogenic kidney survival of >240 min in all experiments. Increase of DD was abolished and the consumption of fibrinogen was abrogated by both treatments as compared to control, whereas the increase of TAT was abolished only by rhAPC. Histological examination revealed no evidence of thrombotic microangiopathy for both treatments as compared to control. In conclusion, the perfusion model introduced here is a suitable tool for studying coagulopathy during early rejection in xenotransplantation. Thrombotic microangiopathy and DIC-like activation of coagulation is associated with an increased flow resistance and failure of perfusion in this model. Pharmacological intervention such as the supplementation of rhAPC or rhAT can be studied using this model and has been shown to prevent coagulopathy and thrombotic microangiopathy.

Effects of indomethacin on energy metabolism in rat jejunal tissue in vivo

2002 ◽  
Vol 102 (5) ◽  
pp. 541-546 ◽  
Author(s):  
Molly JACOB ◽  
Ingvar BJARNASON ◽  
Robert J. SIMPSON
Keyword(s):  
Energy Metabolism ◽  
Oxygen Uptake ◽  
Mitochondrial Function ◽  
Clinical Medicine ◽  
Ex Vivo ◽  
Energy Charge ◽  
Early Event ◽  
Sprague Dawley ◽  
Lactate Levels

The non-steroidal anti-inflammatory drugs (NSAIDs) are a widely used group of drugs in clinical medicine. However, their propensity to cause gastrointestinal damage limits their clinical utility. The pathogenesis of this toxicity is not well established. It has been postulated that an early event in the development of damage is an effect of these drugs on mitochondrial function. The present paper sets out to evaluate the effects of indomethacin, a commonly used NSAID, on energy metabolism in vivo. Indomethacin was administered to male Sprague-Dawley rats, either intrajejunally or orally, and indices of mitochondrial function were determined. The parameters chosen for this purpose were oxygen uptake by, lactate levels in and the energy charge of jejunal tissue. Oxygen uptake by and energy charge in jejunal tissue were unaffected at 1 and 3h after dosing by gavage with indomethacin. The drug significantly affected the tissue lactate/pyruvate ratio at 3h (but not at 1h) after oral dosing. Effects of indomethacin on jejunum incubated ex vivo were found to be reversible. The data suggest that indomethacin affects mitochondrial function in vivo, but that compensatory changes in glycolytic rate maintain energy charge.

CURCUMIN ENHANCES LIVER PRESERVATION BY UNIVERSITY OF WISCONSIN SOLUTION IN AN EX-VIVO PERFUSION MODEL

1999 ◽  
Vol 67 (9) ◽  
pp. S649
Author(s):  
Thomas D. Johnston ◽  
Kunam S. Reddy ◽  
Gaughan Wu ◽  
Changgou Chien ◽  
Molky Nagabhusan ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Liver Preservation ◽  
University Of Wisconsin Solution ◽  
Ex Vivo Perfusion ◽  
University Of Wisconsin ◽  
Perfusion Model ◽  
Wisconsin Solution

325-I * ELASTIC PROPERTIES OF THE JUVENILE AORTA: NEW INSIGHTS FROM A NOVEL PORCINE EX-VIVO PERFUSION MODEL

2014 ◽  
Vol 19 (suppl 1) ◽  
pp. S97-S97
Author(s):  
T. Kruger ◽  
A. Grigoraviciute ◽  
K. Veseli ◽  
D. Schibilsky ◽  
H. P. Wendel ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Ex Vivo ◽  
Ex Vivo Perfusion ◽  
Perfusion Model

scholarly journals Off-pump tricuspid valve repair by automated sutured tricuspid annular plication via transatrial cannulation: preclinical ex vivo and in vivo results

2019 ◽  
Vol 30 (4) ◽  
pp. 636-645
Author(s):  
Paul Werner ◽  
Marco Russo ◽  
Jude Sauer ◽  
Robert Zilberszac ◽  
Claus Rath ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Tricuspid Valve ◽  
Human Heart ◽  
Ex Vivo ◽  
Invasive Technique ◽  
Tricuspid Valve Repair ◽  
Off Pump ◽  
Ex Vivo Perfusion ◽  
Perfusion Model

Abstract OBJECTIVES Surgical repair is considered the gold standard treatment for severe symptomatic tricuspid valve (TV) regurgitation. However, patients undergoing isolated surgical tricuspid repair face a high perioperative mortality while long-term data on interventional treatment options are currently missing. We investigated a novel, minimally invasive approach for transatrial off-pump beating-heart tricuspid annular plication based on the surgical Hetzer repair. METHODS TV annular plication for the creation of a double-orifice valve using novel devices for automated annular suturing was performed in 10 human heart specimens in an ex vivo perfusion model under endoscopic guidance. Additionally, the technique was tested in an in vivo porcine model using the transatrial access under echocardiographic and fluoroscopic guidance. RESULTS Endoscopically guided conduction of the procedure was successful in all 10 human heart specimens in the ex vivo perfusion model with 1 observed suture pull-through of 60 sutures placed (1.7%). TV measurements yielded significant reductions of the TV septal–lateral diameter (50.9 ± 7.3 vs 42.6 ± 7.9 mm; P = 0.015) and the TV area (1208 ± 399 vs 193 ± 122 mm2; P &lt; 0.0001). TV plication without direct vision using device-embedded intracardiac echocardiography, epicardial echocardiography and fluoroscopy was feasible in both acute animals with no observed device-related adverse events. CONCLUSIONS Successful plication was completed in 10 ex vivo human hearts, additionally proof-of-concept was conducted in 2 animals. We herein present encouraging early preclinical results of a novel minimally invasive technique for TV repair, which warrants further investigation.

scholarly journals Abstract No. 130 Evaluation of an experimental radiopaque microsphere in an ex vivo perfusion model

2021 ◽  
Vol 32 (5) ◽  
pp. S58
Author(s):  
R. Bitar ◽  
L. Garza ◽  
Matt Parker ◽  
C. Ortiz ◽  
R. Suri ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Ex Vivo Perfusion ◽  
Perfusion Model
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