Clinical and Haemodynamic Results of Aortic Valve Replacement with the Björk-Shiley Tilting Disc Valve Prosthesis

Abstract

One hundred and one patients with aortic valve disease, aortic stenosis 29 patients, aortic insufficiency 29 patients and combined lesions in 43 patients, underwent valve replacement with the Björk-Shiley tilting disc prosthesis. Early and late mortality rate 8% and 3% respectively. Six patients died in heart failure, 2 after a myocardial infarction, one due to cardiomyopathy, one of septicaemia and one due to carcinoma of the stomach. No thrombo-embolic complications were encountered.Fifty-seven of the patients were subjected to a follow-up study 6 to 8 months after surgery, including right and left heart catheterization. All these 57 patients were subjectively improved by the operation and 30/57 were considered to be in an excellent clinical condition.The heart volume in supine decreased on average 20% after operation. The exercise tolerance (Wmax) increased in 24/57 patients. There were marked decreases in left ventricular systolic and end diastolic pressures. Pulmonary arterial and right heart pressures decreased significantly. The relationship between cardiac output and oxygen uptake at rest and during exercise remained unchanged. The peak systolic pressure difference at rest across the 21 mm prosthesis was on average 22 mmHg, across the 23 mm prosthesis 13.8 mmHg, across the 25 mm prosthesis 9.3 mmHg and across the 27 mm prosthesis 10.7 mmHg. During exercise only moderate increases in the peak systolic pressure difference were found.A slight to moderate regurgitation was found at aorto-graphy in 12/57 patients. Marked regurgitation was only present in two patients, one of whom was reoperated.Intravascular haemolysis due to mechanical destruction was minimal and without clinical significance. All patients had normal values for total haemoglobin and haemoglobin concentration. Plasma haptoglobin was present in all patients. Low obstruction to flow, absence of thrombo-embolic complication and haemolysis seem to be important characteristics of tilting disc valve prosthesis.