Decontamination of heart valve and arterial allografts in the European Homograft Bank (EHB): comparison of two different antibiotic cocktails in low temperature conditions

Abstract

The aim of the study was to compare the efficiency of two different antibiotic cocktails in the cardiovascular allograft decontamination. Low temperature, low-concentration antibiotic cocktail with Cefoxitin, Lincomycin, Polymixin B and Vancomycin was decontamination protocol in EHB for many years. The modified cocktail doesn't contain Cefoxitin. The study had two steps. First step: cardiovascular allografts from 80 donors are incubated in classical (group 1) or modified cocktail (group 2). Second step: 184 and 182 allografts of group 1 and group 2 are incubated in the modified and classical antibiotic cocktail, respectively. The bacteriological examination is performed in three steps: A-transport solution, B-decontamination solution and C-cryopreservation solution. During the first step 23.75% of the tissues were initially contaminated mainly with Staphylococcus (78.95%). 93.75% of the allografts of group 1 and 100% of group 2 were sterile after incubation (p = 0.058). 25.54% and 30.77% of group 1 and 2, respectively were contaminated in A-examination during the second step. Staphylococci were isolated in 82.98% and 69.64% in group 1 and 2, respectively. About 4.35% of group 1 and 5.5% of group 2 were contaminated in A, B, and C whereas 5.4% of group 1 and 4.4% of group 2 were contaminated in B or C after being sterile in A. Finally 9.78% of the tissues were rejected and 90.22% cryopreserved in the modified, whereas 9.89% rejected and 90.11% accepted in the classical group (p = 0.1). The difference was non-significant in the level of decontamination between the two cocktails. Contamination of some tissues with low growing, low-pathogen germs that appeared in B or C examination, couldn't be explained. This issue needs complementary investigation.

Evaluation of decontamination process of heart valve and artery tissues in European Homograft Bank (EHB): a retrospective study of 1,055 cases

“…The proceeded heart valve and artery tissues are incubated in the antibiotic cocktail at the temperature of 4°C for between 20 and 48 h not exceeding 72 h. The preliminary results have revealed that this 3-antibiotics' cocktail achieved a decontamination rate equivalent to that of the former 4-antibiotics' cocktail (Jashari et al 2007). However, the study group of this previous report is rather small.…”

“…Although the setting of antibiotic treatment does have a significant impact on decontamination success, to date, no consensus exists on an optimal formula. Several different decontamination protocols are applied in the different tissue banks (Angell et al 1976;Strickett et al 1983;Kirklin et al 1987; BarrattBoyes et al 1987;Gall et al 1995;Stolinski et al 2006;Jashari et al 2007). The differences between these protocols are mainly in the composition and concentration of antibiotic cocktail, the temperature and the duration of antibiotic incubation.…”

Determination of Residual Antibiotics in Cryopreserved Heart Valve Allografts

“…Therefore, the retrieval of the allograft source material from the NHBDs was envisaged as one of the possibilities for increasing the yield of cardiovascular allografts. Consequently, some of the procured cardiovascular tissues arriving in the Tissue Establishments are primarily contaminated [8]. Earlier methods used for allograft decontamination were harmful for allograft integrity [14][15][16][17][18][19].…”

“…Different Tissue Establishments worldwide, responsible for cardiovascular allograft decontamination, have adopted different cocktails of antibiotics, under different temperature conditions and for varying duration [4][5][6]. Since the cell viability preservation of the heart valves signifies the valve quality preservation [7], many antibiotics such as antimycotic drugs [8] were removed from some decontamination protocols. Some long-term studies on implanted allografts have shown that allograft viability is a prerequisite for graft survival [7][8][9].…”

“…Since the cell viability preservation of the heart valves signifies the valve quality preservation [7], many antibiotics such as antimycotic drugs [8] were removed from some decontamination protocols. Some long-term studies on implanted allografts have shown that allograft viability is a prerequisite for graft survival [7][8][9]. Although the antibiotic cocktail is referred to as low dose, the concentrations are far in excess to the doses used clinically for the treatment of systemic infections and well above the concentrations required to inhibit most microorganisms [10].…”