Transcutaneous oxygen tension (TcpO2) at rest, sensitized by oxygen inhalation tests, is widely applied for the evaluation of chronic critical limb ischemia (CLI). If foot TcpO2 measurements are good prognostic factors of the risk of amputation or the probability of wound healing without amputation, they have never proven their hability to estimate the risk of death in patients with critical limb ischemia. On the one hand, studies have considered only the response observed on legs without considered the thoracic variations. On the other hand, the variability of the TcpO2 signal has never been analyzed as a prognostic factor.

The objective of the NOVICE study is therefore to assess, first, whether the variability of resting TcPO2 values at thoracic probe as well as at affected limb probe is a morbidity-mortality prognostic factor and secondly, to evaluate during the oxygen tests, if the measurement of the amplitude of the distal responses in ischemic zone compared to the response observed in thoracic probe is a prognostic factor of morbi-mortality.

This is an ambispective (both retrospective and prospective) cohort study in which any major patient, referred for resting (transcutyaneous oxygen pressure = TcpO2) for suspicion of critical limb ischemia, is included retrospectively and prospectively from November 2018 to October 2020. Tcpo2 recording are analysed to determine specific parameters (signal variability and response top oxygen). A morbidity-mortality follow-up is carried out between 12 and 15 months after the Tcpo2 measurement. A Kaplan Mayer study of these indices against MALE (major adverse lower limb events ) and MACE(Major adverse cardiovascular events) will be carried out.

Inclusion Criteria:

• Suspicion of Critical limb ischemia
• Reffered for Tcpo2 Absence of rebuttal to the use of the data by the patients

Exclusion Criteria:

• No available tcpo2 recording
• Rejection of the follow up by the patients

Patients referred for Tcpo2 recording for suspicion of critical limb ischemia.