Banking of Heart Valves

Abstract

The first aortic valve was implanted into a patient at Guys Hospital in London by Donald Ross in 1962 [1] and over the following 45 years major changes have occurred in the processing of heart valves. The first valves were preserved using chemical agents such as formalin, glutaraldehyde, beta propriolactone and in the latter years of the decade ethylene oxide. Prosthetic valves, mainly of the ball in the cage variety or tilting disc, were introduced in the previous decade to the allograft and in the sixties these were the two main types of valves that were used [2, 3]. Xenograft valves were introduced in the seventies being mainly the porcine aortic valve [4], with valves made from bovine pericardium following later in the decade [5]. Also around this time surgeons tried to manufacture heart valves from human tissue with autologous fascia lata [6] being the first material tried and later homologous dura mater [7], and both autologous and homologous pericardium being tried [8]. In the present millennium there are only really three types of valves regularly being implanted and these are bileaflet prosthetic valves, porcine xenografts (which can be stented or unstented) and allografts. Seventy five percent of the allografts are used nowadays in paediatric cases with a further 15% in adult congenital cardiac surgery and the final 10% in adult acquired surgery, particularly in redo operations and patients with bacterial or fungal endocarditis. The advantages and disadvantages of allografts are given in Table 5.1.