Pulsatile perfusion system for ex vivo investigation of biochemical pathways in intact vascular tissue

1996 ◽  
Vol 270 (2) ◽  
pp. H760-H768 ◽  
Author(s):  
R. F. Labadie ◽  
J. F. Antaki ◽  
J. L. Williams ◽  
S. Katyal ◽  
J. Ligush ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Ex Vivo ◽  
Pearson Correlation ◽  
Vessel Diameter ◽  
Perfusion System ◽  
Vascular Perfusion ◽  
Hemodynamic Variables ◽  
Morphological Studies ◽  
Confocal Scanning ◽  
Pulsatile Perfusion

We have constructed and performed initial validation of an innovative perfusion system that allows exposure of intact segments of vascular tissue to realistic physiological and hemodynamic environments ex vivo. Computer-controlled opening and closing of an in-line gate valve allows generation of arterial pressure waveforms. The control algorithm predicted resultant pressure waveforms with a high degree of accuracy (Pearson correlation coefficient > 0.97). To document vascular homeostasis ex vivo, vasomotor bioassays and morphological studies were performed. The bioassays consisted of injecting epinephrine (2 x 10(-3) mg/ml) into the perfusion system followed by acetylcholine (100 microM) while concurrently measuring vessel diameter with a laser micrometer, significant vasomotion was measured for canine carotid arteries (n = 4) bioassayed after 1, 24, and 48 h of perfusion (P < 0.03). Additionally, human saphenous vein segments were perfused for 24 h (n = 4) and viewed with laser confocal scanning microscopy and transmission electron microscopy; photomicrographs show typical vascular morphology. We conclude that the vascular perfusion system described herein is well suited for investigating the response of intact vascular tissue to hemodynamic variables.

Design and Subspace System Identification of an Ex Vivo Vascular Perfusion System

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Mohammed S. El-Kurdi ◽  
Jeffrey S. Vipperman ◽  
David A. Vorp
Keyword(s):  
System Identification ◽  
Transfer Functions ◽  
Controller Design ◽  
Ex Vivo ◽  
Numerical Algorithms ◽  
Perfusion System ◽  
Vascular Perfusion ◽  
Roller Pump ◽  
In Series ◽  
Subspace System Identification

Numerical algorithms for subspace system identification (N4SID) are a powerful tool for generating the state space (SS) representation of any system. The purpose of this work was to use N4SID to generate SS models of the flowrate and pressure generation within an ex vivo vascular perfusion system (EVPS). Accurate SS models were generated and converted to transfer functions (TFs) to be used for proportional integral and derivative (PID) controller design. By prescribing the pressure and flowrate inputs to the pumping components within the EVPS and measuring the resulting pressure and flowrate in the system,_four TFs were estimated;_two for a flowrate controller (HRP,f and HRPP,f) and two for a pressure controller (HRP,p and HRPP,p). In each controller,_one TF represents a roller pump (HRP,f and HRP,p),_and the other represents a roller pump and piston in series (HRPP,f and HRPP,p). Experiments to generate the four TFs were repeated five times (N=5) from which average TFs were calculated. The average model fits, computed as the percentage of the output variation (to_the_prescribed_inputs) reproduced by the model, were 94.93±1.05% for HRP,p, 81.29±0.20% for HRPP,p, 94.45±0.73% for HRP,f, and 77.12±0.36% for HRPP,f. The simulated step, impulse, and frequency responses indicate that the EVPS is a stable system and can respond to signals containing power of up to 70_Hz.

A simple physiologic pulsatile perfusion system for the study of intact vascular tissue

2000 ◽  
Vol 22 (6) ◽  
pp. 441-449 ◽  
Author(s):  
Brian S Conklin ◽  
Scott M Surowiec ◽  
Peter H Lin ◽  
Changyi Chen
Keyword(s):  
Vascular Tissue ◽  
Perfusion System ◽  
Pulsatile Perfusion

102 Functional and metabolic phenotyping of the murine heart using an ex vivo perfusion system and 13C-substrates

2003 ◽  
Vol 2 (1) ◽  
pp. 12
Author(s):  
M KHAIRALLAH ◽  
B BOUCHARD ◽  
J MCDUFF ◽  
F LABARTHE ◽  
G DANIALOU ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Perfusion System ◽  
Metabolic Phenotyping ◽  
Ex Vivo Perfusion

scholarly journals Assessment of Electrospun Pellethane-Based Scaffolds for Vascular Tissue Engineering

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3678
Author(s):  
Vera Chernonosova ◽  
Alexandr Gostev ◽  
Ivan Murashov ◽  
Boris Chelobanov ◽  
Andrey Karpenko ◽  
...  
Keyword(s):  
Vascular Tissue ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Wistar Rat ◽  
Graft Occlusion ◽  
Suitable Candidate ◽  
Large Animals ◽  
Cell Adhesion And Proliferation

We examined the physicochemical properties and the biocompatibility and hemocompatibility of electrospun 3D matrices produced using polyurethane Pellethane 2363-80A (Pel-80A) blends Pel-80A with gelatin or/and bivalirudin. Two layers of vascular grafts of 1.8 mm in diameter were manufactured and studied for hemocompatibility ex vivo and functioning in the infrarenal position of Wistar rat abdominal aorta in vivo (n = 18). Expanded polytetrafluoroethylene (ePTFE) vascular grafts of similar diameter were implanted as a control (n = 18). Scaffolds produced from Pel-80A with Gel showed high stiffness with a long proportional limit and limited influence of wetting on mechanical characteristics. The electrospun matrices with gelatin have moderate capacity to support cell adhesion and proliferation (~30–47%), whereas vascular grafts with bivalirudin in the inner layer have good hemocompatibility ex vivo. The introduction of bivalirudin into grafts inhibited platelet adhesion and does not lead to a change hemolysis and D-dimers concentration. Study in vivo indicates the advantages of Pel-80A grafts over ePTFE in terms of graft occlusion, calcification level, and blood velocity after 6 months of implantation. The thickness of neointima in Pel-80A–based grafts stabilizes after three months (41.84 ± 20.21 µm) and does not increase until six months, demonstrating potential for long-term functioning without stenosis and as a suitable candidate for subsequent preclinical studies in large animals.

Comparison of Centrifugal and Pulsatile Perfusion to Preserve Donor Kidneys Using Ex Vivo Subnormothermic Perfusion

2021 ◽  
pp. 1-7
Author(s):  
Patrick P. W. Luke ◽  
Larry Jiang ◽  
Aushanth Ruthirakanthan ◽  
Daniel Lee ◽  
Qizhi Sun ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Pulsatile Perfusion

scholarly journals Surface modification of decellularized bovine carotid arteries with human vascular cells significantly reduces their thrombogenicity

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Eriselda Keshi ◽  
Peter Tang ◽  
Marie Weinhart ◽  
Hannah Everwien ◽  
Simon Moosburner ◽  
...  
Keyword(s):  
Surface Modification ◽  
Whole Blood ◽  
Carotid Arteries ◽  
Complete Blood Count ◽  
Ex Vivo ◽  
Vascular Grafts ◽  
Blood Perfusion ◽  
Vascular Cells ◽  
Perfusion System ◽  
Human Whole Blood

Abstract Background Since autologous veins are unavailable when needed in more than 20% of cases in vascular surgery, the production of personalized biological vascular grafts for implantation has become crucial. Surface modification of decellularized xenogeneic grafts with vascular cells to achieve physiological luminal coverage and eventually thromboresistance is an important prerequisite for implantation. However, ex vivo thrombogenicity testing remains a neglected area in the field of tissue engineering of vascular grafts due to a multifold of reasons. Methods After seeding decellularized bovine carotid arteries with human endothelial progenitor cells and umbilical cord-derived mesenchymal stem cells, luminal endothelial cell coverage (LECC) was correlated with glucose and lactate levels on the cell supernatant. Then a closed loop whole blood perfusion system was designed. Recellularized grafts with a LECC > 50% and decellularized vascular grafts were perfused with human whole blood for 2 h. Hemolysis and complete blood count evaluation was performed on an hourly basis, followed by histological and immunohistochemical analysis. Results While whole blood perfusion of decellularized grafts significantly reduced platelet counts, platelet depletion from blood resulting from binding to re-endothelialized grafts was insignificant (p = 0.7284). Moreover, macroscopic evaluation revealed thrombus formation only in the lumen of unseeded grafts and histological characterization revealed lack of CD41 positive platelets in recellularized grafts, thus confirming their thromboresistance. Conclusion In the present study we were able to demonstrate the effect of surface modification of vascular grafts in their thromboresistance in an ex vivo whole blood perfusion system. To our knowledge, this is the first study to expose engineered vascular grafts to human whole blood, recirculating at high flow rates, immediately after seeding.

Successful ex vivo liver perfusion system for hepatic failure pending liver regeneration or liver transplantation

2001 ◽  
Vol 33 (1-2) ◽  
pp. 1962-1964 ◽  
Author(s):  
G.M Abouna ◽  
P Ganguly ◽  
S Jabur ◽  
W Tweed ◽  
H Hamdy ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Liver Regeneration ◽  
Hepatic Failure ◽  
Ex Vivo ◽  
Liver Perfusion ◽  
Perfusion System

Arterial baroreceptor reflexes in young and old racing greyhounds

1981 ◽  
Vol 240 (3) ◽  
pp. H383-H390
Author(s):  
R. H. Cox ◽  
R. J. Bagshaw ◽  
D. K. Detweiler
Keyword(s):  
Carotid Sinus ◽  
Peripheral Resistance ◽  
Iliac Arteries ◽  
Hemodynamic Variables ◽  
Baroreceptor Reflexes ◽  
Before And After ◽  
Mean Pressure ◽  
Central Hemodynamic ◽  
Cervical Vagotomy ◽  
Pulsatile Perfusion

The characteristics of the carotid sinus baroreceptor (CSB) reflex control of arterial pressure-flow relations were studied in young (18 mo) and old (10.5 yr) racing greyhounds anesthetized with chloralose. Pressure and flow were simultaneously measured in the ascending aorta, the celiac, superior mesenteric, renal, and iliac arteries under steady-state conditions of pulsatile perfusion of the isolated carotid sinuses before and after bilateral cervical vagotomy. Operating-point (OP) values of mean pressure were not significantly different between the young or old greyhounds, but OP values of cardiac output were lower and of peripheral resistance were higher in the older animals. OP values of regional resistances were higher in the older animals, but only those of the celiac and mesenteric beds were significantly different. Values of OP sensitivity of central hemodynamic variables were not decreased in the older animals. OP values of renal and iliac resistance sensitivity tended to be lower in the older animals. The overall range of control of the various hemodynamic variables by the CSB was lower in the older group only in the case of iliac resistance. The characteristics of the CSB were not uniformly depressed in the older animals but were relatively well maintained compared with those of the younger group.

Vessel-Sealing Capability of Novel Microwave Sealer: Experimental Study in Animal Models

2020 ◽  
pp. 155335062093786
Author(s):  
Khiem Tran Dang ◽  
Shigeyuki Naka ◽  
Atsushi Yamada ◽  
Ken-ichi Mukaisho ◽  
Tohru Tani
Keyword(s):  
Thermal Damage ◽  
Ex Vivo ◽  
Vessel Diameter ◽  
Heating Process ◽  
Damage Evaluation ◽  
Vessel Sealing ◽  
Surgical Devices ◽  
Harmonic Focus ◽  
Thermal Spread

Background. Ultrasonically activated dissectors (UADs) and radiofrequency-based devices have been considered excellent surgical devices because of their reliability and flexibility. Meanwhile, microwave-based devices have demonstrated potential with their unique heating mechanism. This study aims to compare the sealing function of a newly invented forceps-like microwave sealer (MS) with that of currently available UADs. Materials and Methods. MS and 2 examples of UADs (Harmonic Focus+ [HF+] and Sonicision [SNC]) were employed to perform mesenterectomies (in vivo) and sealing sizable vessels (ex vivo). Vessel diameter, seal time, burst pressure (BP), sealing completion, and instrument sticking were recorded. The samples underwent histological investigation for thermal damage evaluation. Results. During mesenterectomies, MS required 3 seconds and 30 W to secure a complete seal. The BP achieved by the MS seal was higher than that of HF+ and SNC on arteries (851 ± 203.7 vs 682.4 ± 287.3, P < .05; vs 833.1 ± 251.2 mmHg, P = .4523, respectively) but was not statistically different on veins (324.9 ± 203.5 vs 460.1 ± 320.3 vs 508.3 ± 350.7 mmHg, P = .215). In all trials, MS caused less sticking but exhibited similar heat-induced alterations to UADs. MS’s thermal spread was not statistically more extended than that of UADs on either arteries or veins. Conclusions. MS was capable of not only sealing tiny vessels but also achieving high-pressure endurance on sizable vessels. Its forceful grasping and synchronous heating process helped create solid stumps with an acceptable thermal spread.

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