This study aims at evaluating the correlation between foot perfusion on angiographies performed before and after revascularization and limb salvage in patients with critical limb ischemia.

Critical limb ischemia (CLI) in diabetic patients is increasing drastically worldwide, and is already recognized as a major health issue. CLI is frequently leading to major amputations. Therefore, one of the key point to prevent limb loss is to restore a good vascularization to the foot, usually thanks to endovascular means.

No consensual indicator is currently available to estimate if the limb revascularization will be sufficient or not to prevent amputation, and to help physicians decide if they should be more aggressive during the endovascular procedure. Transcutaneous oximetry and value of the ankle-brachial index (ABI) are commonly used in the ward (not available in the operating room), but have shown poor correlation to wound healing or limb salvage and results are frequently biased because of the arterial wall calcifications due to diabetes. Value of the first toe systolic pressure is currently under evaluation to predict survival without amputation, with promising results, but cannot be applied to patients with wounds at this level or previous minor amputation.

The emergence of hybrid rooms in the operating theater offer access to high quality imaging and image post-treatment. Those capabilities could be used to analyze the flow and the tissue perfusion in the foot, and correlate those imaging parameters to positive clinical outcomes, such as wound healing, thus creating a useful tool to guide physicians in daily practice.

Differences between foot angiographies performed before and after revascularization could be used to estimate the quality of the revascularization and predict wound healing and limb salvage. This method would be directly available in the operating room and could help physicians to optimize their strategy during the procedure

Inclusion Criteria:

• Patients with critical limb ischemia Rutherford 4, 5 and 6, with at least one pre-operative exam (CTA, magnetic resonance angiography or ultrasound) demonstrating a peripheral arterial disease, and requiring an endovascular or hybrid (meaning combined with a surgical technique) revascularization of the lower limb.

Exclusion Criteria:

• Patients not willing to give their consent to study enrollment
• Patients under 18 years old
• Patients with severe renal insufficiency (estimated creatinine clearance < 30 mL/min), without dialysis
• Patients with life threatening septic wounds who would require an amputation at the initial presentation

Patients suffering from peripheral arterial disease in critical limb ischemia (Rutherford 4, 5 and 6) at the initial presentation, with a major risk of limb amputation at mid-term without revascularization.