[Cineradiographical significance for diagnosis and treatment of thrombosed Björk-Shiley prosthesis in the aortic position].

In the periods between February 1973 and December 1987, 377 Björk-Shiley valve prostheses have been implanted in the aortic position in our institute. The maximum opening angle of the prosthesis have been cineradiographically measured in 30 cases. The maximum opening angle of the convexo-concave valve having an opening angle of 60 degree (CC 60) was measured as 58.8 +/- 1.9 degree and that of the monostrut valve having an opening angle of 70 degree was 69.4 +/- 2.1 degree. During this period we have experienced 6 cases of thrombosed Björk-Shiley prosthesis. They have shown restriction of the opening from 26 to 58.9 degree and restriction of the closing from 9.2 to 41.8 degree. Thrombolytic treatment was successful in case with thrombosed Björk-Shiley prosthesis which showed restriction of the opening angle on cineradiogram. 4 cases with restriction of the closing angle on cineradiogram were treated operative thrombectomy. Three of them have had uneventful reoperative course in the follow up period of 8 years. We believe that cineradiography is very useful for not only diagnosis but also decision of management for thrombosed Björk-Shiley prosthesis in the aortic position.