Belgian and European Experience with the European Homograft Bank (EHB) Cryopreserved Allograft Valves.-Assessment of a 20 Year Activity

Abstract

European Homograft Bank (EHB) has been selecting, preparing, storing and distributing the cryopreserved allograft valves in Belgium and some other European Countries since 1989. It was established in 1988 by a pathologist and the cardiac and vascular surgeons from Belgian and other European centres as an inter-university, international nonprofit association. Due to its neutral behavior and very high quality criteria, European Homograft Bank became one of the prominent heart valve banks in Europe and wider. It collaborates with the transplant coordination in donor selection as well as with the huge network of the implanting surgeons in Belgium and other European Countries. The EHB responsible discusses with the implanting surgeon the allograft selection on basis of the indication and the patients state of emergency. A total of 8.911 donor heart valves have been evaluated in EHB during the last 20 years. After selection, 5.258 allograft valves (1.996 aortic, 3.189 pulmonary and 73 mitral) were cryopreserved and stored in vapors of liquid nitrogen between 6 weeks and 5 years. A total of 4.516 allograft valves (1.391 aortic, 2.620 pulmonary and 48 mitral) were implanted in the left or right ventricular outflow tract for replacement of the diseased aortic or pulmonary valve and for mitral or tricuspid valve replacement or repair. In 1.380 cases the allograft valves were used for right ventricular outflow tract reconstruction as part of the Ross- procedure, whereas in 668 cases the allograft valve served for replacement of the aortic valve for endocarditis. The most important indications for use of cryopreserved allograft valves were: important cardiac and valve malformation in children, female patients of child-bearing age with diseased cardiac valves, cases with contra-indication for anti-coagulation and the patients with severe endocarditis with septal or annular abscesses. Although the number of the donation increased by year, the available allograft valves in stock are still insufficient to respond to all the surgeons' request for different indications.

Bacterial adherence to graft tissues in static and flow conditions

“…The CH thawing process was done in accordance with instructions from the EHB. 7 All tissues were rinsed using 0.9% NaCl before use. A 10-mm Acu-Punch (Acuderm, Fort Lauderdale, Fla) was used to cut circular tissue pieces, as illustrated in Video 1.…”

“…[2][3][4] Implantation of a competent pulmonary valve in RVOT reconstruction or Ross procedure can be achieved by surgical or transcatheter implantation of cryopreserved human pulmonary homograft (CH) and bovine jugular vein (BJV) grafts. 2,[5][6][7] Recent observations have increased awareness of the risk for IE after successful transcatheter implantation of a stent-mounted BJV conduit. 2,[8][9][10] Comparative studies have showed a significantly higher incidence of IE in BJV grafts compared with surgically implanted CH grafts.…”

Surgical treatment of aortic valve endocarditis with aortic annular involvement: a 26-years experience

“…The disease is highly fatal because of the infectious process that can lead to sepsis and the destructive process that can have significant consequences with regard to cardiac function. Recent reports on cryopreserved homografts are promising, [9][10][11][12] but there is no substitute for radical debridement in these cases. [13] The use of biological materials for patients with aortic PVE is recommended due to the low reinfection rates caused by the increased penetration of antibiotics in these tissues and the presence of viable cells.…”

Cutting-Edge Regenerative Medicine Technologies for the Treatment of Heart Valve Calcification

“…After isolation, donor tissues are examined to exclude lacerations and/or unsuitability sources and graded following macroscopic qualitative evaluation. Antimicrobial procedures are then performed to eliminate bacterial and fungal infective risks with constant control for effective microbe removal [243,244]. Decontaminated tissues are immersed in cryopreserving solutions, usually based on cell culture medium added with a low percentage of the cryoprotectant dimethyl sulfoxide (DMSO).…”