Pericardial tissue regeneration by urinary bladder matrix scaffolds in a preclinical porcine model

AMIGO, NATALIA; RIGANTI, JUAN MARTIN; RAMÍREZ, MAURICIO ; LORENZI, ANDREA; RENDA, PEDRO; LOVERA, ROMINA; PASCANER, ARIEL; VIGLIANO CARLOS; CRAIEM, DAMIÁN; YOUNG, D. ADAM; GILBERT, THOMAS W.; NIEPONICE, ALEJANDRO

Mar del Plata

Congreso; XIV Encuentro Biólogos en Red 2019; 2019

Pericardium closure after cardiac surgery is recommended to prevent postoperative adhesionsto the sternum. Synthetic materials have been used as substitutes, with limitedresults because of impaired remodeling and fibrotic tissue formation. Urinary bladdermatrix (UBM) scaffolds promote constructive remodeling that more closely resemble thenative tissue. The aim of the study is to evaluate the host response to UBM scaffolds in aporcine model of partial pericardial resection. Twelve Landrace pigs were subjected to amedian sternotomy. A 5 7 cm pericardial defect was created and then closed with a 5 7cm multilayer UBM patch (UBM group) or left as an open defect (control group). Animalswere survived for 8 wk. End points included gross morphology, biomechanical testing,histology with semiquantitative score, and cardiac function. The UBM group showed mildadhesions, whereas the control group showed fibrosis at the repair site, with robust adhesionsand injury to the coronary bed. Load at failure (gr) and stiffness (gr/mm) werelower in the UBM group compared with the native pericardium (199.9 59.2 versus405.3 99.89 g, P ¼ 0.0536 and 44.23 15.01 versus 146.5 24.38 g/mm, P ¼ 0.0025,respectively). In the UBM group, the histology resembled native pericardial tissue, withneovascularization, neofibroblasts, and little inflammatory signs. In contrast, control groupshowed fibrotic tissue with mononuclear infiltrates and a lack of organized collagen fibersvalidated with a histologic score. Both groups had normal ultrasonography results withoutcardiac motility disorders. In this setting, UBM scaffolds showed appropriate features forpericardial repair, restoring tissue properties that could help reduce postsurgical adhesionsand prevent its associated complications.