[Porcine acellular dermal matrix for repair of abdominal wall defects in rabbit model]

To research the effect of porcine acellular dermal matrix in the reconstruction of abdominal wall defects in rabbits, and to investigate the application feasibility of xeno-transplantation of acellular dermal matrix.

The porcine acellular dermal matrix was prepared from a health white pig. Twenty-six Japanese white rabbits (weighing 2.2-2.3 kg, female or male) were randomly assigned to 2 groups: the control group (n=6) and the experimental group (n=20). In the control group, the full-thickness abdominal wall defect of 5.0 cm x 0.5 cm was made, and the defect was sutured directly; in the experimental group, the full-thickness abdominal wall defect of 5.0 cm x 2.5 cm was made, and the defect was repaired with porcine acellular dermal matrix patch at the same size as the defect. At 5 weeks after surgery, the incidence of hernia and the intra-abdominal adhesions were observed and the wound breaking strength was compared between the patch-fascia interface and the fascia-fascia interface. The graft vascularization was evaluated through histological analysis at 6 months after surgery in the experimental group.

No hernia occurred in all rabbits of 2 groups. At 5 weeks after surgery, healing was observed between patch and the muscular fascia; the vascularization was seen in the porcine acellular dermal matrix patch. There was no significant difference in the adhesion grade (Z= -0.798, P=0.425) between the experimental group (grade 2 in 1 rabbit, grade 1 in 5, and grade 0 in 12) and the control group (grade 1 in 1 and grade 0 in 5). No significant difference was found (t= -0.410, P=0.683) in the breaking strength between the patch-fascia interface in the experimental group [(13.0 +/- 5.5) N] and the fascia-fascia interface in control group [(13.6 +/- 4.0) N]. In the experimental group, the small vessels and the infiltration of inflammatory cells were observed in the porcine acellular dermal matrix patch after 5 weeks through histological observations. The junctions of the patch-fascia interface healed with fibrous connective tissue. At 6 months after surgery, the inflammation was subsided and the collagen fiber of the patch was reconstructed.

The porcine acellular dermal matrix patch has good results in repairing full-thickness abdominal wall defect. The patch-fascia interface has similar breaking strength to the fascia-fascia interface. The collagen fibers of the patch are reconstructed.