ABSTRACT
Six years after the first aortic valve replacement with the Starr-Edwards Silastic ball prosthesis at Oregon Health Sciences University, the model 1260 was implanted in a 44-year-old patient at our department. During 24 years no signs of dysfunction, thromboembolism, thrombosis, periprosthetic leaks or hemolysis were observed. Material test showed no signs of fatigue. The dimension of the Silastic poppet was found to be one millimeter less than the original specifications of these poppets and there were some lipid infiltrations. Functionally the poppet was found to be nonvariant. Histologic findings detected focal hyalinization and giant cells without signs of acute inflammation or ulceration. With regard to its reliability and durability, the Starr-Edwards valve prosthesis should not be viewed with disfavor.
Subject(s)
Aortic Valve Stenosis/surgery , Heart Valve Prosthesis , Adult , Aortic Valve Stenosis/rehabilitation , Evaluation Studies as Topic , Follow-Up Studies , Foreign-Body Reaction/etiology , Heart Valve Diseases/complications , Heart Valve Diseases/surgery , Heart Valve Prosthesis/adverse effects , Hemodynamics , Humans , Male , Silicone Elastomers , SiliconesABSTRACT
This paper reviews and discusses a technique that can be used to study the dynamics of populations under the influence of favourable or unfavourable environmental factors or the stress of population control. It is encouraging for those interested in the sterility approach to pest control that the reproductive success of insects with a reputedly high biotic potential is limited to relatively low rates under field conditions. Further studies are needed under other conditions, in other areas, and with other species.
