RESUMO
BACKGROUND: The aim of this study was to examine whether transplantation of adipose-derived stem cells (ADSCs) improves healing of a gastrotomy closure in rats. In digestive surgery, anastomotic leakage is a serious postoperative complication and anastomotic stenosis may reduce quality of life. Recent studies have suggested that ADSCs play material roles in intestinal healing, acceleration of angiogenesis, and reduction of fibrosis, and treatment with ADSCs may improve healing. MATERIALS AND METHODS: ADSCs were isolated from intra-abdominal white adipose tissue of 40 male Wistar rats (weight 300 g) in four groups (n = 10 each). Gastrotomy closures were prepared surgically in all rats. Controls were treated with phosphate-buffered saline injection and sacrificed 7 d (group 1) or 28 d (group 3) after the surgery. Other animals were treated with locally autotransplanted ADSCs (labeled by CM-DiI) and sacrificed 7 d (group 2) or 28 d (group 4) after the surgery. Histopathologic features were evaluated in the four groups. RESULTS: Injection of ADSCs significantly enhanced angiogenesis and collagen deposition after 7 d, indicating improved healing of the gastrotomy closure. In contrast, ADSC transplantation significantly reduced collagen deposition after 28 d. The bursting pressure was higher in the transplant groups after 7 d. CONCLUSIONS: ADSCs enhance tissue regeneration in gastrotomy closures by accelerating angiogenesis and fibrosis in the early healing period. In the late period, ADSCs prevent excessive fibrosis and assist in regeneration of tissues that closely resemble the native structure. These results suggest that therapy with transplanted ADSCs might improve postoperative complications in digestive surgery.