Improving Blood Compatibility of Cardiovascular Devices by Surface Modification

2007 ◽  
Vol 342-343 ◽  
pp. 801-804 ◽  
Author(s):  
Nan Huang ◽  
Ping Yang ◽  
Yong Xiang Leng ◽  
Jun Ying Chen ◽  
Jin Wang ◽  
...  
Keyword(s):  
Surface Modification ◽  
Artificial Heart ◽  
Heart Valves ◽  
Blood Compatibility ◽  
Artificial Heart Valve ◽  
Cardiovascular Devices ◽  
Inorganic Films ◽  
Artificial Heart Valves ◽  
Plasma Grafting ◽  
Circulation Tube

This paper presents recent activities on the surface modification of blood contacting biomaterials and devices in the author’s laboratory. Surface coating of inorganic films on materials for artificial heart valves, ventricular pumps and coronary stents, such as titanium, stainless steel and low temperature isotropic pryolitc carbon, etc, shows a significant improvement in the anticoagulation behavior. Further, the formation of functional groups such as hydroxyl or amino groups and the binding of biomolecules as well as seeding of endothelial cell shows the promise of biomimetic surface formation. Plasma grafting on materials for artificial heart valve sewing cuff, extracorporeal circulation tube, etc, such as PET, PU, PVC polymers, revealed a significant improvement of anti-platelet adhesion as well as anti-bacterial properties.

Anticoagulation after Artificial Valve Replacement with or without Atrial Fibrillation: How Much Is Really Needed?

1999 ◽  
Vol 82 (S 01) ◽  
pp. 130-135 ◽  
Author(s):  
Freek W. A. Verheugt
Keyword(s):  
Atrial Fibrillation ◽  
Heart Valve ◽  
Oral Anticoagulation ◽  
Artificial Heart ◽  
Heart Valves ◽  
Oral Anticoagulant Therapy ◽  
International Normalized Ratio ◽  
Artificial Heart Valve ◽  
Artificial Valve ◽  
Artificial Heart Valves

SummaryInsertion of a mechanical artificial heart valve is an absolute indication for the use of lifelong oral anticoagulation, irrespective the presence or absence of atrial fibrillation. Depending on the type and position of the artificial valve the optimal International Normalized Ratio (INR) for these patients is between 2.5 and 4.5, although more prospective studies on the optimal range of oral anticoagulation are necessary. Addition of low dose antiplatelet therapy may further decrease the rate of thromboembolism, but also here more studies are needed. Patients with a bioprosthesis need only oral anticoagulation for the first three months following surgery in the absence of an indication for anticoagulation for other conditions.Atrial fibrillation is often seen in patients with artificial heart valves. Stroke prevention can be instituted by the mandatory oral anticoagulant therapy. The presence of atrial fibrillation and the use of oral anticoagulation prior to heart valve surgery support the indication for the insertion of a mechanical artificial heart valve. However, relative contraindications to oral anticoagulation and the presence of sinus rhythm may favor the use of a bioprosthesis.

scholarly journals Use of Computational Fluid Dynamics to Analyze Blood Flow, Hemolysis and Sublethal Damage to Red Blood Cells in a Bileaflet Artificial Heart Valve

Fluids ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 19 ◽  
Author(s):  
Madison James ◽  
Dimitrios Papavassiliou ◽  
Edgar O’Rear
Keyword(s):  
Blood Flow ◽  
Red Blood Cells ◽  
Heart Valve ◽  
Blood Cells ◽  
Artificial Heart ◽  
Heart Valves ◽  
High Stress ◽  
Leading Edge ◽  
Artificial Heart Valve ◽  
Artificial Heart Valves

Artificial heart valves may expose blood to flow conditions that lead to unnaturally high stress and damage to blood cells as well as issues with thrombosis. The purpose of this research was to predict the trauma caused to red blood cells (RBCs), including hemolysis, from the stresses applied to them and their exposure time as determined by analysis of simulation results for blood flow through both a functioning and malfunctioning bileaflet artificial heart valve. The calculations provided the spatial distribution of the Kolmogorov length scales that were used to estimate the spatial and size distributions of the smallest turbulent flow eddies in the flow field. The number and surface area of these eddies in the blood were utilized to predict the amount of hemolysis experienced by RBCs. Results indicated that hemolysis levels are low while suggesting stresses at the leading edge of the leaflet may contribute to subhemolytic damage characterized by shortened circulatory lifetimes and reduced RBC deformability.

PATIENTS WITH ARTIFICIAL BUT NOT BIOLOGICAL HEART VALVE PROSTHESIS PRESENT A HYPERCOAGULABILITY RELATED TO THE INTENSITY OF ANTICOAGULATION

1987 ◽  
Author(s):  
V Pengo ◽  
M Boschello ◽  
P Peruzzi ◽  
D Pagotto ◽  
L Schivazappa ◽  
...  
Keyword(s):  
Heart Valve ◽  
Healthy Subjects ◽  
Artificial Heart ◽  
Heart Valves ◽  
Oral Anticoagulants ◽  
Heart Valve Prosthesis ◽  
Artificial Heart Valve ◽  
Valve Prosthesis ◽  
Artificial Heart Valves ◽  
Thrombin Formation

Long term anticoagulant therapy is mandatory for patients with artificial heart valve prosthesis and is suggested for some patients with biological heart valve prosthesis. Oral anticoagulants reduce but not abolish thromboembolic complication in these patients. They act lowering the level of vitamin K-dependent coagulation factors and that in turn should result in a depression of "in vivo" thrombin formation. Fibrinopeptide A (FpA) is a good marker of thrombin formation and therefore we ascertained in several occasions the thrombin formation in 43 patients with artificial and 18 with biological heart valve prosthesis, all the patients being on oral anticoagulant treatment at least from 1 year. FpA was significantly higher in patients with artificial (determinations n = 138) with respect to biological (n=73) heart valve prosthesis (p 0.01). The FpA level in biological valves was close to that obtained in 22 not anticoagulated healthy subjects. When we divided FpA values in artificial heart valves according to the intensity of anticoagulation, we obtained a decreasing FpA mean levels with the increase of the degree of anticoagulation. In particular FpA values with an INR 4.5 were close to values obtained in healthy subjects. These data support the concept that patients with artificial heart valves are at higher risk of thromboembolism and therefore the intensity of anticoagulation should be different with respect to biological valves and probably a little higher than that recommended at the Leuven Consensus Conference.

scholarly journals Numerical Study of Blood Flow Through Artificial Heart Valves

2021 ◽  
Vol 1094 (1) ◽  
pp. 012120
Author(s):  
Hussein Togun ◽  
Ali Abdul Hussain ◽  
Saja Ahmed ◽  
Iman Abdul hussain ◽  
Huda Shaker
Keyword(s):  
Blood Flow ◽  
Artificial Heart ◽  
Heart Valves ◽  
Numerical Study ◽  
Artificial Heart Valves ◽  
Flow Through

On polymeric mobile elements in artificial heart valves and changes occurring in these elements under the action of the blood and its components

1977 ◽  
Vol 19 (6) ◽  
pp. 1537-1544
Author(s):  
E.I. Semenenko ◽  
A.I. Ivanov ◽  
M.A. Markelov ◽  
N.B. Dobrova ◽  
Ye.V. Smurova ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Heart Valves ◽  
Mobile Elements ◽  
Artificial Heart Valves
Sign in / Sign up

Export Citation Format

Share Document