First Successful Regeneration of a Structurally Native‐Like Colon Using a Bioabsorbable Polymer Sheet

ABSTRACT Background and Aim In cases of colonic perforation, closure of the defect is the least invasive treatment; however, no dedicated tool has been developed for this purpose, and many cases require stoma creation. This study investigated whether a bioabsorbable polymer sheet (BAPS) can effectively close colonic perforation and induce colonic regeneration at the defect site. Methods Ten mixed‐breed pigs were used. An artificial colon was created using a BAPS composed of a copolymer reinforced with polyglycolic acid fibers. A circular 2‐cm defect was created on the anterior sigmoid colon wall, and the BAPS was patched over the defect. Blood sampling and body weight assessments were performed at 1, 4, and 8 weeks after transplantation. Furthermore, the transplanted site was excised for macroscopic and histological evaluation at 4 and 8 weeks. Results All pigs survived without complications. White blood cell counts exhibited a transient increase at 1 week but normalized rapidly. Body weight increased consistently. At 4 weeks, the BAPS was no longer observed at the transplanted site, and ulcer formation was noted. Histologically, several immature cells accumulated on the epithelial surface. At 8 weeks, the ulcers had reduced in size, and the site was indistinguishable from the surrounding tissue. Histological examination revealed regenerated mucosa and muscularis mucosae resembling native colonic tissue with partial smooth muscle regeneration. The size of the transplanted site was reduced by approximately 26%. Conclusions The findings suggest that a BAPS can successfully close colonic perforations and regenerate colonic tissue at the defect site.