Changes of the cutaneous flowmotion pattern after limb revascularization in patients with critical ischemia

The skin flowmotion of 13 patients suffering from critical limb ischemia (CLI) was studied with wavelet analysis (WA) of the laser Doppler signals (LDS). The WA selects six different frequency components (FCs), each relating to a specific cardiovascular system structures activities; FC I 1-2 Hz heart, FC II 0.2 Hz respiratory, FC III 0.1 Hz myogenic, FC IV 0.04 Hz, sympathetic, FC V 0.01 Hz, and FC VI 0.007 Hz endothelial. The aim of the study was to observe which FC changed after the limb revascularization. The LDS was measured at the dorsum of the foot, one week before and no later than 30 days after revascularisation. The absolute and relative amplitude and energy of the flowmotion WA FCs, the ankle brachial pressure index (ABI) and the transcutaneous pressure of oxygen (TcpO2) were assessed before and after revascularization. The results showed that after successful revascularization ABI and TcpO2 increased from 0.34 ± 0.10 to 0.54 ± 0.09 (p 0.0003) and from 20.3 ± 13.4 to 43.8 ± 18.7 mmHg (p 0.0002) whereas only the absolute amplitude and energy of the cardiac FC I increased from 0.57 ± 0.44 to 1.07 ± 0.69 (P 0.002) AU and 1.14 ± 1.78 AU2 to 3.54 ± 3.78 AU2 (p 0.004). In conclusion after limb revascularization the cardiac component of the flowmotion increased maybe because the cardiac stroke volume had more influence over the skin arterioles.