DCB can maximize the patency rate of blood vessels on the basis of intraluminal DA. DA+DCB treatment is effective and safe [8], and the advantages of DA and DCB in the treatment of severe calcification and occlusive disease across joints and lower extremities have been confirmed. The combined application of DA and DCB in the treatment of peripheral arterial disease has a good early and mid-term effect. Konstantinos et al. reported that DARRT has a higher first-phase patency rate compared with DCB. A retrospective study by Sebastian et al. showed that compared with PTA after DA, the combination of DA and DCB has a better event-free survival rate after 12 months of follow-up. Therefore, DA combined with DCB therapy may be one of the best and most promising methods for the treatment of lower extremity ASO.

Inclusion Criteria:

• Age over 18 years old
• Ruthford grade 2-5 patients
• For patients whose arteries in both lower extremities meet the enrollment criteria, both lower extremities can be included
• At least one outflow tract over 10 cm at the distal end of the knee is continuous with a healthy back of the foot or internal and external arteries of the plantar
• The guide wire clearly passed through the lesion and the follow-up treatment was performed. In the case of failed anterograde passage, reverse puncture to achieve the guide wire through the lesion can also be included in the group
• After the failure of the first intracavitary treatment, the blood vessel can be recanalized by the intracavitary treatment again, and it can still be included in the group
• Patients with aortic iliac artery disease can be included in the group after the aortic artery is opened
• Patients who are willing to participate in this study and sign informed consent
• For severely infected R6 patients, if the infection is effectively controlled, they can be considered for inclusion

Exclusion Criteria:

• Patients who refuse to participate in this observational study
• Femoral popliteal artery disease with acute and subacute thrombosis
• Patients with thromboangiitis
• Patients who have failed endovascular treatment and transferred to surgical treatment
• For patients who have received plaque exfoliation on the femoral artery
• Patients who are allergic to heparin, low molecular weight heparin and contrast agents
• Patients enrolled in other clinical studies in the past 3 months
• Pregnant women
• Patients who have a life span of less than 2 years due to serious diseases

ASO patients with femoral popliteal artery occlusion