Abstract:With advances in endovascular techniques and devices, thoracic endovascular aortic repair and endovascular aneurysm repair have evolved from relatively standardized procedures to complex multibranched reconstruction strategies, including fenestrated, branched, parallel-graft, and physician-modified endograft techniques. Compared with standard endovascular repair, complex endovascular aortic repair usually involves longer aortic coverage, incorporation of multiple target vessels, more frequent guidewire and catheter manipulations, and greater device dependence. Accordingly, the spectrum of perioperative severe complications has changed substantially. In addition to conventional complications such as endoleak and stent-graft migration, target-vessel loss or injury, access-related vascular injury, cardiac and cerebrovascular events, spinal cord ischemia, aortic rupture or new-onset dissection, and device-related failure may markedly compromise procedural safety and long-term outcomes. The success of complex endovascular aortic repair depends not only on appropriate procedural planning and technical execution, but also on the ability to identify, prevent, and promptly manage complications. This review focuses on severe perioperative complications associated with complex endovascular aortic repair. Based on recent guidelines, published evidence, and clinical experience, it summarizes the mechanisms, risk factors, preventive strategies, and management principles of major complications. A whole-process management strategy centered on meticulous preoperative assessment, standardized intraoperative manipulation, dynamic perioperative monitoring, and multidisciplinary collaboration is emphasized to improve the safety and clinical effectiveness of complex endovascular aortic repair.