A novel approach for intestinal elongation using acellular dermal matrix: an experimental study in rats.

We tested the hypothesis that an anatomic scaffold placed in continuity with viable bowel might allow intestinal growth. Male ACI rats were used for the study. Acellular human dermis in the form of tubular scaffolds with an intraluminal diameter of approximately 0.3 cm was oriented with the luminal basement membrane and serosal dermal surface. The small bowel was transected approximately 2 cm distal to the ligament of Treitz. The graft was then anastomosed in continuity in group A (n = 5) or as a blind-ended pouch to a defunctionalized jejunal limb in group B (n = 8). The animals were sacrificed at various time points. Histology and immunohistochemistry were used to evaluate structural changes. Animals in group A developed peritonitis and were all sacrificed within the first week postoperatively. However, all animals in group B survived, increasing their body weight similarly to age-matched rats. Tissue samples obtained at sacrifice showed a progressively increasing amount of cellular infiltrate over time in the matrix. Epithelial regeneration, angioneogenesis, and myofibroblast infiltrate were seen at 2 weeks, while well-formed branching crypts were seen at 4 weeks. Intact mucosa extended across the anastomosis to the grafts at 6 months. This study demonstrated an anatomic scaffold of acellular matrix allowed mucosal regeneration from viable bowel placed in continuity. These findings set the basis for new intestinal elongation techniques.