More advanced and severe cases of chronic lower limb ischemia (the so-called critical lower limb ischemia) are painful and limiting conditions that impact on patients' quality of life.

Until now, the available evidence for the femoropopliteal area only defines open surgery or endovascular treatment indications. However, the best strategy for endovascular procedures is still unclear. The popliteal artery is a challenging anatomical site for balloon angioplasty alone and standard nitinol stenting angioplasty.

This randomized clinical trial aims to assess the superiority of nitinol stent angioplasty compared to pharmacoactive balloon angioplasty to treat critical lower limb ischemia due to popliteal artery arteriosclerosis.

Arteriosclerosis is a systemic and multi-etiological disease that causes arterial degeneration, narrowing their lumens and reducing perfusion in their respective territories. Chronic lower limb ischemia is one manifestation of arteriosclerosis. It may be initially asymptomatic, but patients usually present with pulselessness and intermittent lower limb claudication. More advanced and severe cases present with rest pain, the so-called critical lower limb ischemia.

Critical lower limb ischemia usually benefits from revascularization and requires cautious surgical planning with complementary imaging tests able to locate the lesion site precisely. In our setting, the most used test is arterial cartography with doppler ultrasound. Afterward, surgeons should decide whether to perform open surgery or endovascular treatment.

Until now, the available evidence for the femoropopliteal area only defines open surgery or endovascular treatment indications. However, the best strategy for endovascular procedures is still unclear. Given its anatomy, the popliteal artery undergoes many flexion-extension and rotational movements, making it a challenging site for balloon angioplasty alone (high incidence of restenosis) and standard nitinol stenting angioplasty (risk of stent fractures).

Mimetic stents have been developed to overcome the risk of stent fractures. They consist of multiple intertwined nitinol wires that provide greater radial resistance and allow for even stress distribution.

This randomized clinical trial aims to assess the superiority of nitinol stent angioplasty compared to pharmacoactive balloon angioplasty to treat critical lower limb ischemia due to popliteal artery arteriosclerosis.

Inclusion Criteria:

1. Patients diagnosed of critical lower limb ischemia according to the TASC (TransAtlantic Inter-Society Consensus) working group.
2. Patients admitted to the Vascular Surgery Department of the Bellvitge Hospital University to treat critical lower limb ischemia for endovascular treatment.
3. With involvement of the Popliteal artery in-between the Hunter's canal and the start of the tibial artery branch.
4. WOCBP must use highly effective methods of contraception.
5. Patients who sign the written informed consent.

Exclusion Criteria:

1. Patients diagnosed of critical lower limb ischemia according to the TASC working group undergoing medical treatment or open surgery.
2. Patients requiring amputation.
3. Patients who underwent previous revascularization of the same limb (same artery).
4. The main involvement is from an arterial territory other than the popliteal artery.
5. Pregnant women.
6. Inability of overcoming the arterial lesion during the endovascular procedure.
7. Affected artery's diameter <4 mm.