Comparison of Cross-linked and Non–Cross-linked Acellular Porcine Dermal Scaffolds for Long-term Full-Thickness Hernia Repair in a Small Animal Model

BACKGROUND This study compared the strength of incorporation and biocompatibility of 2 porcine-derived grafts (cross-linked and non-cross-linked) in a rat hernia model. METHODS A standardized 2 × 4 cm(2) fascial defect was created in 30 Wistar rats and repaired with either a cross-linked or a non-cross-linked graft. The rats were killed 3, 6, and 12 months later. The strength of incorporation, vascularization, cellular invasion, foreign body reaction, and capsule formation were evaluated. RESULTS Both graft materials showed cellular ingrowth and neovascularization by 3 months postimplantation. The average level of cellularization was significantly higher in the non-cross-linked grafts than in the cross-linked grafts at 6 months (2 vs 1; P = .029). Vascularization was significantly higher in the non-cross-linked grafts than in the cross-linked grafts at 6 months postimplantation (2 vs 1; P = .029) and insignificant at 3 months (2 vs 1.75; P = .311) and 12 months (1 vs 0.67; P = 1). The maximum load and breaking strength of both biomaterials increased during the study period. Overall, the strength of incorporation of the non-cross-linked grafts increased from 3 months (0.75 MPa) to 12 months (3.06 MPa) postimplantation. The strength of incorporation of the cross-linked grafts also increased from 3 months (0.59 MPa) to 12 months (1.58 MPa) postimplantation. CONCLUSIONS The results of our study suggest that non-cross-linked grafts may be slightly more biocompatible and allow a more rapid and higher degree of cellular penetration and vascularization, resulting in stronger attachment to the tissues.