Durability of pulmonary homografts for reconstruction of the right ventricular outflow tract: how relevant are donor-related factors?

OBJECTIVES: Our goal was to evaluate the influence of donor-related factors on the durability of pulmonary homografts (PHGs) for right ventricular outflow tract reconstruction of congenital heart defects. METHODS: Between 1990 and 2016, 223 PHGs were used in 197 patients for right ventricular outflow tract reconstruction. Long-term durability was investigated in relation to patient- and disease-specific as well as to donor-related factors, based on the PHG replacement rate. To minimize the effect of outgrowth, a subgroup analysis was performed on patients with PHG size >22 mm, as the discriminant cut-off identified by the classification tree method. RESULTS: During a median follow-up of 8.5 years [interquartile range (IQR) 12.3], 47 (21%) PHGs were explanted within a mean interval of 9.5 ± 5.3 years, resulting in a freedom from PHG replacement of 82 ± 6% at 10 years. The risk factors for PHG explantation determined by univariable analysis were predominantly patient-related, including younger age (P = 0.003), extra-anatomic implantation (P = 0.006), bicuspidalization (P = 0.002) and younger donor age (P = 0.032). PHG size [hazard ratio (HR) 0.80, 95% confidence interval 0.73-0.88; P < 0.001] was the only independent determinant in multivariable analysis. The subgroup analysis comprised 119 PHG >22 mm, implanted at a median age of 15 years (IQR 7). A significant beneficial effect of ABO matching on the explantation rate was only identified with univariable analysis (HR 0.24, 95% confidence interval 0.12-4.68; P = 0.010). CONCLUSIONS: Cryopreserved PHGs provide a durable substitute for right ventricular outflow tract reconstruction in congenital heart disease. PHG size at the time of implantation remains the principal determinant of PHG explantation during late follow-up. However, once an adult-sized homograft is required, matching for ABO blood group compatibility between host and donor might help to improve homograft durability.

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

To evaluate the efficiency of decontamination practice in European Homograft Bank (EHB), the data of the cardiovascular tissues received during recent 2 years were retrospectively analysed in this study. After initial assessment, the tissues were incubated in a 3-antibiotics' cocktail at 4°C for 20-48 h. The states of contamination were evaluated before and after incubation with the focus on the differences in donor type, tissue type, germ type and incubation time. Amongst 1,055 eligible tissues, 77.2% were hearts and 22.8% were arteries. 82.2% of the tissues were retrieved from the multi-organ donors (MOD), 15.4% from the recipients of heart transplantation (RHT) and 2.4% from the non-heart beating donors (NHBD). The initial contamination rate was 27.4% with a significantly higher incidence in arteries. The RHT tissues had the lowest contamination rate comparing to that of MOD and NHBD. Staphylococcus species was the major source of contamination. After antibiotic incubation, 76.8% of the contaminated tissues were disinfected, which was significantly higher for the hearts than the arteries. The RHT tissues had the highest decontamination rate than that of MOD and NHBD tissues. Propionibacterium acnes was detected in 48.1% of the remaining contaminated cases. The average incubation time of the Propionibacterium-positive tissues was significantly shorter than that of decontaminated tissues. In conclusion, the current decontamination protocol of EHB is sufficient for most of the initially contaminated bacteria, whereas it is inadequate for Propionibacterium acnes. This may be related to the slow-growing nature of this bacterium and thereby the relative shorter antibiotic incubation time.

The incidence of congenital bicuspid or bileaflet and quadricuspid or quadrileaflet arterial valves in 3,861 donor hearts in the European Homograft Bank.

BACKGROUND AND AIM OF THE STUDY: The incidence of bicuspidity and quadricuspidity of arterial valves in donor hearts has been assessed in the European Homograft Bank. METHODS: Morphologically unacceptable donor valves for clinical use were assessed for cusp or leaflet malformation, identifying the different valve types. The state of the adjacent valve was also evaluated. Histological evaluations of the corresponding conduits were performed, in order to assess the incidence of media degeneration. RESULTS: Among 3,861 donor hearts, 39 (1.0%) showed congenital cusp or leaflet malformation of one or both arterial valves, 28 (0.7%) showed bicuspid or bileaflet aortic valves (BCAV), four (0.1%) showed bicuspid or bileaflet pulmonary valves (BCPV), and eight (0.2%) showed quadricuspid or quadrileaflet pulmonary valves (QCPV). Only in one case (0.03%) were both arterial valves bicuspid or bileaflet. Among the bicuspid arterial valves, 27 (84%) were isolated aortic valves, three (9%) were isolated pulmonary valves, and in one case (3%) both the aortic and pulmonary valves were bicuspid or bileaflet. CONCLUSION: The most frequently identified congenital malformation of the arterial valves was aortic bicuspidity, followed by pulmonary quadricuspidity and bicuspidity. If asymptomatic, these were detected during routine echocardiography, or at autopsy. These malformations might be genetically determined, as they are detected more often among different members of the same families, and in those persons of the same gender or blood group. These valves have a predisposition to accelerated calcification, stenosis, endocarditis and dissection of the ascending aorta. Neither quadricuspid/quadrileaflet nor unicuspid/monoleaflet aortic valves were detected in this study.