AIM: To investigate the efficacy of acellular dermal matrix (ADM) for intestinal elongation in animal models.METHODS: Japanese white big-ear rabbits ( n = 9) and Wuzhishan miniature pigs ( n = 5) were used in the study. Home-made and commercial ADM materials were used as grafts, respectively. A 3-cm long graft was interposed in continuity with the small bowel and a sideto-side anastomosis, distal to the graft about 3-4 cm,was performed. The animals were sacrificed at 2 wk,4 wk, 8 wk and 3 mo after surgery and the histological changes were evaluated under light microscope and electron microscope.RESULTS: The animals survived after the operation with no evidence of peritonitis and sepsis. Severe adhesions were found between the graft and surrounding intestine. The grafts were completely absorbed within postoperative two or three months except one. Histological observation showed inflammation in the grafts with fibrinoid necroses, infiltration of a large amount of neutrophils and leukomonocytes, and the degree varied in different stages. The neointestine with wellformed structures was not observed in the study.CONCLUSION: It is not suitable to use acellular dermal matrix alone as a scaffold for the intestinal elongation in animal models.