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Open in new tab Download slide OBJECTIVES The goal of this histological study was to assess the biocompatibility of vascular patches used in the repair of congenital heart defects. METHODS We examined tissue-engineered bovine (n = 7) and equine (n = 7) patches and autologous human pericardium (n = 7), all explanted due to functional issues or follow-up procedures. Techniques like Movat-Verhoeff, von Kossa and immunohistochemical staining were used to analyse tissue composition, detect calcifications and identify immune cells. A semi-quantitative scoring system was implemented to evaluate the biocompatibility aspects, thrombus formation, extent of pannus, inflammation of pannus, cellular response to patch material, patch degradation, calcification and neoadventitial inflammation. RESULTS We observed distinct material degradation patterns among types of patches. Bovine patches showed collagen disintegration and exudate accumulation, whereas equine patches displayed edematous swelling and material dissolution. Biocompatibility scores were lower in terms of cellular response, degradation and overall score for human autologous pericardial patches compared to tissue-engineered types. The extent of pannus formation was not influenced by the type of patch. Bovine patches had notable calcifications causing tissue hardening, and foreign body giant cells were more frequently seen in equine patches. Plasma cells were frequently detected in the neointimal tissue of engineered patches. CONCLUSIONS Our results confirm the superior biocompatibility of human autologous patches and highlight discernible variations in the changes of patch material and the cellular response to patch material between bovine and equine patches. Our approach implements the semi-quantitative scoring of various aspects of biocompatibility, facilitating a comparative quantitative analysis across all types of patches, despite their inherent differences. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide Open in new tab Download slide OBJECTIVES The aim of this study was to report our initial experience when using Matrix Patch™ a cell-free equine-derived pericardium for the augmentation of branch pulmonary arteries (PAs) in children. METHODS Between September 2016 and September 2019, Matrix Patch was used for the augmentation of branch PAs in 96 patients and implanted in 147 separate locations. The median age at implantation was 3.2 years (interquartile range: 0.9–8.4), and 33% of patients were infants. The patch was used mainly in redo surgeries (89.6%). Intra-procedural feasibility and reinterventions were analysed. Primary end points were death or patch-related reoperation/stent implantation. Explanted patches were stained for recellularization/calcification, or to reveal proliferation/inflammation. RESULTS A total of 81 patients, who received patches in 119 separate locations, were followed within a median of 20 months (interquartile range: 10.2–30.2). Patients with early reoperation/stent implantation were excluded from follow-up. No patch-related death was noted. Survival at last follow-up was 88% (95% CI: 78.8–93.7%). Overall probability of freedom from reoperation/stent implantation per location, 12 and 24 months after initial surgery was 85.8% (95% CI: 76.2–91.7%) and 78.7 (95% CI: 65.9–87.2%), respectively. At 20 months, superficial proliferation with discrete macrophage activity was seen in explants; however, no signs of calcification are observed. CONCLUSIONS The initial experience with the Matrix Patch in PAs showed comparable results to other xenogeneic patch materials. Long-term follow-up data are needed to prove the desired durability of the patch in different locations. [ABSTRACT FROM AUTHOR]