Chronic intravascular haemolysis after aortic disc valve replacement Comparative study between Lillehei-Kaster and Bjork-Shiley disc valve prostheses

Abstract

A randomized series of 64 patients was studied haematologically one year after single aortic valve replacement either with a Lillehei-Kaster pivoting disc valve or a Bjdrk-Shiley (Delrin) tilting disc valve. Patients had haemoglobin concentrations, red blood cells counts, serum bilirubin, serum iron, total iron-binding capacity, serum haptoglobin, and serum lactate and hydroxybutyrate dehydrogenase performed. All patients had normal haemoglobin values and normal red blood cells counts. Haptoglobin was absent or reduced in 8o per cent, while raised values for serum lactate dehydrogenase were found in 75 per cent. The increase in serum lactate dehydrogenase activity was moderate and indicated a normal or only slightly reduced red cell lifespan in most patients. The incidence and severity of haemolysis were of the same order of magnitude in patients with a Lillehei-Kaster prosthesis as in patients with a Bjdrk-Shiley prosthesis. For both models, intravascular haemolysis was of little clinical significance, and was of less severity than previously reported after replacement with aortic ball valve prosthesis. Paravalvular leakage or pronounced valvular regurgitation were not found to be main determinants of the haemolysis, neither did the valve size seem to be of importance in this connexion. In this respect, our data with the new disc valves differ from the results usually found in patients with ball valves. The reasons for the haemolysis in patients with disc valves are briefly discussed.