Encapsulation of the Björk-Shiley Aortic Disc Valve Prosthesis Caused by the Lack of Anticoagulation Treatment

Abstract

We have never experienced encapsulation or massive thrombosis of a Björk-Shiley aortic valve prosthesis in a patient receiving an adequate anticoagulation treatment. An encapsulation has, however, been described after many different types of heart valve replacements. Early diagnosis and emergency operation are mandatory. We have only encountered two cases of massive thrombosis in Björk-Shiley tilting disc valve prostheses in the aortic position out of 300 implants. Anticoagulant treatment was not given in either case. One patient died before final diagnosis was made and the other underwent an emergency operation. It was possible to clean out all thrombus material on both sides of the valve after temporary removal of ths disc and rotation of the valve. This method cannot, however, be recommended for general use. If the surgeons are not experienced in the proper removal of the disc, they will bend the struts so that the disc will not function properly after re-insertion. The insertion of a new prosthesis is a safer procedure. As we have never found encapsulation of an aortic prosthesis after adequate anticoagulation, this treatment is, therefore, recommended.