BACKGROUND: The freeze-drying blood vessel is an excellent material for vasotransplantation. However, the reports concerning freeze-drying are few, and the mechanical property changes of freeze-dried blood vessel remains poorly understood. OBJECTIVE: Using micro-CT to explore the morphological changes of blood vessel during procedure of freeze-drying. DESIGN, TIME AND SETTING: A single sample observation was performed at the Institute of Refrigeration and Cryogenics, University of Shanghai for Science and Technology. MATERIALS: Fresh pig aorta was obtained from Shanghai Slaughter House. The lyophilizer was produced by SP Industries (USA). TRAPEZIUM LITE texture analyzer was purchased from Shimadzu (Hong Kong) Co., Ltd.METHODS: The differences of mechanical property between fresh aorta and freeze-dried aorta were compared.MAIN OUTCOME MEASURES: ① Temperature curve of freeze-drying procedure. ②The reeze-drying procedure was scanned by micro-CT. ③ Changes of mechanical property were detected by TRAPEZIUM LITE texture analyzer and puncture experiments.RESULTS: During freeze-drying procedure, there were presented layer phenomenon in pig aorta. Compared to the fresh aorta, the freeze-dried aorta after recover water would reduce 40% axial tensile force, increase 45% circumferential tensile force, with 75% puncture stress.CONCLUSION: The freeze-dried blood vessel maintains mechanical property as fresh vessel, thus, freeze-drying can be used for vascular preservation.