Abstract
Thrombus formation at valve is one of the most important problem for antithrombogenicity of artificial heart pump. In our institute, specially designed valve named OED valve has been using in these five years. This valve is a door-type valve with oblique elliptical seat, and valve plate is fixed to pump wall by polyester suture at two points. The function and durability of this valve is very good, and no trouble has been experienced for over hundred cases of animal experiments. However, thrombus formation surrounding the suture as the hinge is the most serious problem for this valve. Thrombus formation at artificial heart valve are shown in table for the goats survived over two weeks.
To protect the thrombus formation at the valve, heparin sac with 3 to 5ml of volume was fixed on the pump wall enclosed the end of valve suture. A small quantity of heparin can diffuse through polyester nitted suture, and thrombus formation surrounding the suture may be prohibited without anticoagulant therapy. As the result of animal experiments, four goats survived over two weeks and in two of them thrombus couldn't be found at the valve, and in other two cases, the thrombus was very little. In all cases, the systemic blood clotting time was maintained within normal range.
As conclusion, this method is effective for protection of thrombus formation in localized area and will be able to apply for other artificial organs.
