Repairing Great Duodenal Defects in Rabbits by ePTFE Patch

Extensive regeneration of the stomach using bioabsorbable polymer sheets

BACKGROUND

The growing prevalence of endoscopic surgery in recent years has led to the minimization of postoperative scarring. However, this procedure does not allow for the regeneration of the resected digestive tract, which compromises the postoperative maintenance of digestive function. In this preliminary study, we developed an artificial gastric wall (AGW) using bioabsorbable polymer (BAP), and evaluated the ability of this BAP patch to repair and regenerate a widely defective gastric wall in an animal model.

METHODS

Pigs were laparotomized under general anesthesia. An 8 × 8-cm, round portion of the anterior gastric wall was excised and replaced by an AGW. The AGW was composed of a copolymer comprising 50% lactic acid and 50% caprolactone. The animals were relaparotomized 4, 8, or 12 weeks after implantation, after which they underwent resection of the entire stomach for gross and histologic evaluation of the graft sites.

RESULTS

All recipient pigs survived until killing. By 4-8 weeks, the graft site revealed progressively fewer mucosal defect after each day. Moreover, the grafted area was indistinguishable from the native stomach 12 weeks after AGW implantation. The structures of the regenerated mucous membrane and muscle layers were identical to those of the native stomach. Furthermore, proton pumps were found in the regenerated tissue.

CONCLUSION

The BAP sheets helped to restore extensive gastric defects without causing any deformation. The use of BAP sheets may become a new therapeutic method that prevents alterations of gastric volume after extensive gastrectomy for stomach cancer and other diseases.

Repair of gastric defects with an equine pericardial patch

PURPOSES

The objective of this study was to test the efficacy of an equine pericardial patch for repairing full-thickness defects of the stomach wall.

METHODS

Circular defects, 1.5 cm in diameter, were created on the anterior wall of the stomach of 12 female New Zealand rabbits. The defects were repaired by an equine pericardial patch. After euthanasia at different time intervals (3 days to 8 weeks) a macroscopic evaluation of the abdominal cavity (including adhesion scoring), mechanical testing and a histological examination of the stomach were performed.

RESULTS

The animals survived the surgical procedure and underwent an uneventful recovery until euthanasia. None of the patches failed. Adhesions were observed in all animals and were significant in 3/12 animals. Bursting pressure testing indicated that the repair was durable and that adequate strength to prevent patch failure was achieved by the second week. A histological examination showed gradual narrowing of the perforation site by mucosal and limited muscular regeneration.

CONCLUSIONS

The equine pericardial patch was successfully used to repair a gastric defect in our experimental model, and it seems that it could have potential as a material suitable for further research concerning the repair of upper gastrointestinal defects.

Salvage repair of anastomotic dehiscence following colon surgery using an expanded polytetrafluoroethylene graft

Anastomotic dehiscence is a serious complication of colorectal surgery that causes death in up to 40% of cases in which it occurs. Edema and inflammation due to abdominal sepsis can prevent the use of standard management (i.e., colostomy, ileostomy or Hartmann's procedure), in which case alternative salvage repair methods are required. The present report describes the treatment of a 73-year-old female patient at high risk of mortality because of intraabdominal sepsis due to suture dehiscence following a right hemicolectomy and ileo-transversostomy. Several surgical repair procedures were tried, but all failed. We then used an expanded polytetrafluoroethylene (ePTFE) graft in salvage repair, and this approach proved successful. This is the first report to describe clinical, macroscopic and histopathological findings, following use of an ePTFE graft in colorectal repair in humans.

Repairing large duodenal injuries in dogs by expanded polytetrafluoroethylene patch

BACKGROUND

One of the most challenging problems in clinical surgery is management of injured duodenum. In this experimental study, we treated large duodenal defects by an expanded polytetrafluoroethylene (ePTFE, Gore-Tex; W.L. Gore, Elkton, MD) soft-tissue patch and compared it with the jejunal serosal patch.

MATERIALS AND METHODS

A duodenal defect (about 50% of the total circumference) was created in the second portion of the duodenum in 20 dogs. The effectiveness and gross and histological examinations of the ePTFE patch technique was compared with the jejunal serosal patch.

RESULTS

No significant difference was found in early survival rates (90.9% versus 88.9%; P = 0.711). The whole grafted area was covered by neomucosa at the end of the sixth week in all animals with the ePTFE patch. The scar was small; no significant narrowing of lumen was noted and serosal healing was uniformly complete. In histological examination, complete coverage of the ePTFE grafts by neomucosa consisting of columnar epithelium with short villous formations was observed.

CONCLUSION

Use of the ePTFE patch method is easy, reliable, and comparable to the jejunal serosal patch. It can be used in the treatment of large duodenal defects, which cannot be repaired by duodenorraphy.

[Porcine submucosa graft for the treatment of duodenal injuries in dogs]

PURPOSE

To evaluate the biocompatibility and effectiveness of porcine SIS (small intestinal submucosa), when used as a patch to repair a defect on the anterior duodenal wall.

METHODS

The experimental study was performed in 8 dogs. A segment of the anterior duodenal wall was removed and the defect was repaired with a patch of porcine intestinal submucosa. On the 120th post operative day the animals were sacrificed and the segment of duodenum containing the patch was removed to a macroscopic and microscopic evaluation.

RESULTS

There was no infection, suture dehiscence or fistula. The microscopic evaluation showed complete re-epithelization in 75% of the cases, with moderate fibroblastic proliferation in 87.5% of the cases.

CONCLUSION

The porcine SIS used as a patch acts as a tissue substitute for repairing induced lesions in duodenal wall of dogs.