Results Of Aortic Valve Replacement With The Kay-Shiley Disc Valve

Abstract

Between August, 1966, and April, 1968, aortic valve replacement with the Kay-Shiley disc valve was performed in 60 consecutive patients at the Department of Thoracic Surgery, Karolinska Sjukhuset, Stockholm. The cumulative mortality rate after an observation period ranging from 1 to 3 years was 22%. There were 4 hospital (7%) and 9 late deaths (15%). The causes of death were infection (6), myocardial infarction (4), myo-cardial failure (1), postoperative renal insufficiency (1) and thrombosis around the prosthesis (1). Thrombo-embolic complications were observed in 4 patients (7%), in all related to discontinuation of the anticoagulant therapy. Partial detachment of the prosthesis necessitating re-operation was present in three patients (5%). Forty-two (90%) of the surviving patients were re-examined about a year after surgery, 39 of them being subjected to a follow-up catheterization and 32 also to thoracic aortography with cinetechnique. All patients considered their condition improved after operation. At follow-up their maximal exercise tolerance had increased in average 35%, the heart volume had decreased with 28% and the intracardiac pressures had diminished significantly. Systolic pressure differences across the prosthesis were observed in all patients, the mean difference at rest being 27 mm Hg, increasing to 38 mm Hg during exercise (average work load 400 kpm/min). Aortography showed that the valve was completely competent in the majority of patients. A minimal or slight regurgitation lateral to the prosthesis was observed in 6 patients (10%) at follow-up. The degree of intravascular haemolysis was low and the haemoglobin values were normal in all patients. Plasma haptoglobin was present in all cases, the mean value being 18 mg%. Aortic valve replacement with the Kay-Shiley disc valve can be accomplished with favourable clinical and haemodynamic results. The residual obstruction for left ventricular outflow does not seem to influence the cardiac performance and is outweighed by the favourable haemodynamic properties of the valve: good function during tachycardia and exercise, high competency, low degree of wear and haemolysis.