ObjectiveTo investigate the mechanism of tissue necrosis following injection of hyaluronic acid. MethodsTwenty New Zealand white rabbits (40 ears) were used to establish ear complex tissue flap models with blood supply only from the central pair of artery and vein by ligating the anterior pair and other branches. Then the animal models were randomly divided into 4 groups. Group A, B and C were injected with 0.2 ml hyaluronic acid into the periphery of the root portion of the central artery, central vein and central artery, respectively; Group D received cutting and ligation of the central artery (control group). The visual findings, microcirculation changes, skin temperature and percutaneous oxygen saturation were examined at 1, 7, and 14 days after injection. The animals were sacrificed on the 14th day and the ears were studied pathologically. ResultsAll the groups showed different degrees of tissue ischemia. In Group A and D the skin temperature and oxygen saturation were not significantly different before and after injection of hyaluronic acid. The skin temperature and oxygen saturation were decreased one day after injection in Group B, and they gradually increased thereafter (P<0.05). All the ears in Group A, B and D survived. The skin temperature and oxygen saturation in Group C were significantly decreased after injection of hyaluronic acid (P<0.05), and all the ears in Group C developed skin ulceration and necrosis after 7 days. ConclusionInjection of hyaluronic acid into the artery can cause obstruction of distal arterioles and microcirculation disorder, which might be the main cause of skin tissue necrosis.