Search

Rationale: Peripheral artery disease (PAD) is common among the elderly and increases the risk of cardiovascular events, disability and death. PAD course and outcomes depend not only on the condition of macrovasculature but also on the tissue perfusion. We have previously shown that Type 2 diabetic patients with lower extremity ischemia have significantly lower perfusion than healthy volunteers, and the ratio of basal perfusion in the arm and leg (BP1/BP3) measured by incoherent optical fluctuation flowmetry (IOFF) allows to identify hemodynamically significant stenoses. Aim: To analyze associations between perfusion parameters registered by IOFF and the severity of vascular involvement in PAD patients. Methods: This single center cross-sectional study included 38 PAD patients admitted to the Department of Vascular Surgery and Coronary Artery Disease. The arteries were assessed with duplex Doppler ultrasonography (DDU), according to the results of which the PAD severity score and ankle-brachial index (ABI) were calculated. Skin microhemodynamic parameters were recorded by IOFF. The basal perfusion on the arm (BP1), the dorsal foot surface and the toe (BP2 and BP3), the ratio BP1/BP3, local thermal hyperemia (LTH2 and LTH3) and an increase in perfusion after heating on two leg zones (LTH2-BP2, LTH3-BP3) were evaluated and expressed in perfusion units (PU). BP1, BP3, and BP1/BP3 values were additionally measured with laser Doppler flowmetry (LDF). The analysis was performed depending on the degree of arterial involvement determined by DDU for each limb separately (n = 73). There were ≥ 50% stenoses in 15 extremities (Group 1), occlusion of one of the major arteries in 42 (Group 2) and ≥ 2 occlusions in 16 lower extremities (Group 3). Results: In the groups 1, 2 and 3, the values of most parameters estimated by IOFF decreased with an increase in severity of limb lesions. As an example, the respective perfusion parameters for the big toe in the study groups were as follows: BP3 4.0 [2.0; 9.8], 2.2 [0.9; 3.7] and 1.1 [0.7; 2.6] PU (p = 0.007); LTH3 10.0 [6.4; 14.9], 5.0 [1.5; 7.8] and 2.5 [1.4; 4.5] PU (p 0.001), and LTH3-BP3 3.8 [2.6; 7.8], 2.4 [0.6; 4.3] and 1.2 [0.4; 1.5] PU (p = 0.001). The BP1/BP3 ratio in the above mentioned group increased: 1.8 [0.8; 7.7], 7.2 [3.4; 21.3] and 14.2 [6.6; 18.3] (p = 0.004), respectively. No similar trend was found for this parameter registered by LDF. There were significant correlations between the lower extremities perfusion parameters measured by IOFF and ABI, with the correlation coefficients ranging from 0.365 to 0.717 (p 0.05). Conclusion: The functional parameters of the skin microhemodynamics vary with different PAD severity. In addition, they correlate with clinical indicators of atherosclerosis. The IOFF technique can be promising as an additional quantitative method for assessment of microvascular blood flow in patients with PAD.

Introduction: The development of new highly accurate, inexpensive and accessible methods for the detection of lower-extremity peripheral artery disease (LE-PAD) in diabetic patients is required. The aim of this study was to evaluate the accuracy of a new incoherent optical fluctuation flowmetry (IOFF) method in detecting legs with hemodynamically significant stenoses compared to ankle brachial index (ABI) and transcutaneous oximetry (TcPO2) in patients with diabetes mellitus (DM)., Materials and Methods: Patients were recruited into 2 groups. Group 1 included patients with DM without LE-PAD and/or diabetic foot syndrome; Group 2 included patients with DM and LE-PAD. All patients underwent the following measurements: ultrasound (reference method), ABI, TcPO2, and the new IOFF method., Results: The new IOFF method showed a sensitivity of 79.5% and a specificity of 89.8% in detecting limbs with hemodynamically significant stenosis (AUC 0.890, CI 0.822-0.957). TcpO2 allows the diagnosis of LE-PAD with 69.2% sensitivity and 86.2% specificity (AUC 0.817, CI 0.723-0.911). Using a standard ABI cut-off of less than 0.9, the sensitivity and specificity for this parameter were 34.5% and 89.7%, respectively. Increasing the diagnostic cut-off of the ABI on the study group to 0.99 improved sensitivity to 84.6% and specificity to 78% (AUC,0.824 CI 0.732-0.915)., Conclusions: The new IOFF technique has demonstrated high sensitivity and specificity in the detection of LE-PAD in patients with DM. The high accuracy, rapid measurement, and potential availability suggest that the new IOFF method has a high potential for clinical application in the detection of PAD., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

(1) Background: To date, there are no studies evaluating the ability of the incoherent optical fluctuation flowmetry (IOFF) method to assess foot tissue perfusion. The aim of this study was to evaluate the correlation between perfusion values measured by IOFF and TcPO2 in patients with diabetes-related lower-extremity complications. (2) Methods: This was an observational, cross-sectional, two-center study. Diabetic patients with peripheral artery disease and/or diabetic foot ulcers were studied (n = 27, examinations were carried out on 54 legs). Perfusion in the foot tissues was assessed using TcPO2 (reference standard for this study) and the IOFF method. (3) Results: High correlation coefficients of all perfusion parameters measured by IOFF with TcPO2 (Rs 0.7 to 0.76) were shown. The study demonstrated that the IOFF method allows, with a sensitivity of 85.7% and a specificity of 90.0%, the identification of patients with a critical decrease in TcPO2 < 20 mmHg. (4) Conclusions: The high correlation of IOFF parameters with TcPO2 and the moderately high sensitivity and specificity in detecting patients with severe ischemia of foot tissues shows the promise of the method for assessing a tissue perfusion in patients with diabetes-related lower-extremity complications.