ObjectiveTo assess the causes and risk factors of multiple-intervention in endovascular aortic repair (EVAR) for type B aortic dissection (TBAD). MethodsWe retrospectively analyzed the clinical data of 347 TBAD patients initially treated with EVAR in our hospital between January 1999 and December 2013. The patients were stratified into a multiple-intervention group (34 patients) and a single-intervention group (313 patients). We analyzed the differences of clinical data of the two groups. ResultsThere were 9 patients with endoleak, 10 patients with new dissection, 8 patients with incomplete thrombosis of the false lumen, 4 patients with new aneurysm, 2 patients with retrograde dissection, and 1 patient with iliac artery occlusion in the multiple-intervention group. Higher proportions of chronic dissection and smoking occurred in the multiple-intervention group (79.4% versus 50.8%, 61.8% versus 40.3%, P=0.002, 0.018, respectively). Both of the degree and proportion of hyperglycemia were higher in the multiple-intervention group (6.9±2.3 mmol/L versus 5.7±1.8 mmol/L, P=0.027; 44.1% versus 22.7%, P=0.011). There were statistical differences in oversizing rate of grafts (14.6%±3.2% versus 11.3%±2.5%, P<0.001), operation time (172 min versus 82 min, P<0.001), and blood loss (280 ml versus 100 ml, P=0.006) between the two groups. ConclusionEndoleak, new dissection, and incomplete thrombosis of the false lumen are the main causes of multiple-intervention. While in chronic phase, smoking, hyperglycemia, too big oversizing, and complicated lesion or operation are the potential risk factors.