This study is a prospective, multi-center, real world, observational study, which aims at evaluating the intermediate and long-term efficacy of endovascular treatment for TASC C&D aortoiliac occlusive disease .It is estimated that 800 subjects diagnosed with TASC C&D aortoiliac occlusive disease and receive endovascular treatments will be enrolled in nine centers from April 2021 to June 2027 nation-widely. All the subjects will be under follow-up for 60 months. There is no restriction on the endovascular techniques. The primary outcomes covers freedom from TLR at 60 months.

In the past decade, endovascular treatment has become the first-line treatment for iliac artery occlusion, while Aorta - bilateral femoral artery bypass surgery is preferred for more complex iliac artery occlusion. However, recently, with advances in endovascular devices and techniques, endovascular interventions have gradually replaced open surgery in many clinical problems and have shown ideal safety and efficacy.

Currently, the optimal treatment for TASC, C&D iliac artery occlusion is controversial, mostly based on limited data from single centers and few large multicenter databases or registries. In addition, the long-term efficacy of stents implantation in iliac artery disease remind unknown and might be influenced by stent type and calcification. Therefore, the purpose of this study was to evaluate the long-term efficacy and safety of endovascular treatment for TASC, C&D iliac artery occlusion in a multicenter study.

Inclusion Criteria:

1. Rutherford grades 3-6.
2. Follow the follow-up arrangement.
3. Age: 18-80 years old.
4. The target lesions were in the lower abdominal aorta and/or the common iliac artery and/or the external iliac artery.
5. The stenosis degree ≥50%, or restenosis (received PTA or other adjuvant therapy, including bare or covers stents), or complete occlusion, or the presence of aortailiac artery thrombosis after PMT or CDT thrombus clearance, and then further endovascular therapy perfomred.
6. Signed informed consent.

Exclusion Criteria:

1. Known allergy to drugs used in this study, including antiplatelet or anticoagulant drugs, etc.
2. Allergy to iodine contrast agent allergy;
3. Coagulation dysfunction or hypercoagulability;
4. Breast-feeding or pregnant women;
5. Life expectancy < 24 months;
6. Body condition can not tolerate endovascular treatment;
7. Type 2B, type 3 lower limb ischemia patients

The TASC C&D Aorta-iliac occlusion patients.