Incorporation of Integra in tissue defects: a pilot study in the rat model

Integra has been shown to be very useful in accelerating the growth of neodermis. It has found extensive use in case of burns as a primary dressing immediately after a burn, after release of contractures and following scar revision. It has been used to achieve cover after the debridement of extensive infective processes involving the skin. Encouraged by these results we have assessed the application of Integra to augment and/or patch defects of the urinary bladder, diaphragm and the abdominal wall in the rat model. This was a pilot study and involved the incorporation of Integra in the diaphragm, the urinary bladder (extramucosal) and the muscle layer of the abdominal wall. Eight adult Wistar rats were given general anaesthesia and Integra was implanted with absorbable sutures at the sites mentioned. The omentum was hitched to the collagen matrix surface to revascularise the graft. The silicone was left in situ. The operative period was covered with antibiotics. The anaesthesia was then reversed. Postoperatively the rats were given analgesia and feeds started immediately. The rats were sacrificed after 3 weeks. The abdominal cavity was examined for adhesions. The Integra implant along with adjacent tissue was harvested and examined histologically. There were no visible intra-abdominal adhesions. The histology revealed good degree of neovascularisation and fibrosis in and adjacent to the implant. This was comparable to the changes seen in the skin. This pilot study has shown that implanting Integra invokes a similar response in deeper tissues and it can develop neovascularisation from the omentum. Hence, this could find some application in treating congenital conditions such as diaphragmatic hernias, abdominal wall defects and for bladders requiring augmentation. Our initial results are quite encouraging and we feel that this field should be further explored.