The aim of this study is to explore the ability of the non-invasive device ODI-Tech® to monitor changes in microvascular blood flow in patients with lower limb ischemia undergoing the procedure percutaneous transluminal angioplasty (PTA). Microvascular data from patients and healthy case matched controls at baseline will be compared.15 patients and 15 healthy case matched controls will be enrolled.

This clinical investigation is designed as a prospective study of limb skin nutritive capillary perfusion and oxygen extraction in patients with lower limb atherosclerosis and severe symptoms before and following elective PTA.

15 patients with critical lower limb atherosclerosis and ischemia in Rutherford grade 3 - 6 undergoing PTA, as well as 15 healthy case matched controls will be enrolled. Measurements will be performed at baseline, prior to PTA, immediately after PTA, 1 day and 30 days post PTA. Healthy case matched controls will be measured at baseline.

Inclusion Criteria:

• Age ≥18
• Lower limb atherosclerosis and ischemia in Rutherford grade 3-6
• Obstructive infra-inguinal arterial lesions combined with open distal part of the anterior tibial artery
• Scheduled for elective PTA
• Able to give informed consent

Exclusion Criteria:

• Active skin infection at the region of interest (site to be examined, dorsum of hand and foot)

De-identified individual participant data supporting the results of the study.

From 6 months after publication of the primary results and until 5 years thereafter.

De-identified data will be made available to qualified researchers who submit a scientific and methodologically sound proposal to the sponsor.