Evaluation of clinical tests to assess perfusion in chronic critical limb ischemia

Background: Evaluation of macro- and microcirculatory tests to confirm diagnosis, and recognize perfusion changes in chronic critical limb ischemia (CLI). Patients and methods: Forty-two consecutive patients with CLI examined at the University Hospital Bern, with 21 included in this prospective follow-up analysis. Patients underwent serial clinical examinations, and assessment of the macro- (ankle arterial pressure [AP], great toe pressure [TP], oscillography) and microcirculation (transcutaneous partial oxygen pressure [tCPO(2)] recumbent, sitting, O-2-inhalation; capillary microscopy) at baseline, 6 weeks after revascularization (group 1; [n = 1]]), or after 10 weeks in patients unsuitable for revascularization (group 2; [n = 10]). Clinical improvement was considered to indicate increased perfusion. Results: Eleven patients with revascularization (11/11), and 2 without revascularization (2/10) showed clinical improvement. AP measurements were not reliable or feasible in 9 (43%), TP in 4 patients (19%), respectively. All measurable pressures were in accordance to clinical course. Oszillography gave a moderate perception of perfusion changes. Baseline tCP02 levels were critical (< 30 mmHg) in all 21 patients, whereas follow-up gave poor correlation with the clinical course. Reliability to detect perfusion changes increased by adding provocation manoeuvers in patients with. clinical improvement (39% [5113] recumbent, 77% [10/13] sitting, 8A [11/13] O-2-inhalation). Capillary microscopy revealed a relevant pathology at the forefoot level in all patients with feasible examinations (18/21), and significant improvements according to the clinical course in 92% of patients (12/13). Conclusions: TP measurements represented most reliable test to confirm diagnosis and-disclose improved perfusion in CLI. TcPO2 measurements in recumbent position gave unreliable results, improved by provocation manoeuvers. Capillary microscopy was reliable, but time consuming and limited by anatomical restrictions.