Abstract: Objective:To evaluate the feasibility and technical advantages of 3D guidance technique in endovascular aortic repair.Methods:This was a retrospective single center study.From November 2016 to December 2018，38 patients undergoing thoracic endovascular aortic repair（TEVAR）or endovascular aortic repair（EVAR）with assistance of 3D guidance technique and intraoperative DynaCT.Meanwhile，40 patients were received standard endovascular aortic repair（control group）.The proximal anchorage area was insufficient for branch vascular reconstruction in 16 patients.Comparative analysis of intraoperative and followup data between the two groups was undertaken.Results:The results of this study showed that compared with conventional DSA，3D guidance technique and intraoperative DynaCT reduced contrast dose（TEVAR 60.31ml vs 73.34ml P=0.032；EVAR 83.43ml vs 94.83ml P=0.013），intraoperative radiation dose（TEVAR 293.04mGy vs 385.71mGy P=0.002；EVAR 431.84mGy vs 584.51mGy，P=0.043），number of radiography（TEVAR 2.36 vs 3.56，P=0.016；EVAR 3.43 vs 4.01，P=0.029），operation time（TEVAR 64.09min vs 71.42min P=0.001；EVAR 142.14min vs 153.39min P=0.057），meanwhile，reduced the risk of postoperative aortarelated reintervention（2.63% vs 10% P=0.042），meeting the precise requirements for anatomical positioning and immediate effect determination during endovascular aortic repair.Conclusion:3D guidance technique improves the accuracy during positioning in complex endovascular aortic repair，could reduce aorticrelated reintervention rate，radiation exposure time and contrast dose.Further studies and development are needed to obtain optimal image quality and higher precision.

Key words: endovascular aortic repair, 3D guidance, DynaCT