Assessment of Lower Limb Microcirculation: Exploring the Reproducibility and Clinical Application of Laser Doppler Techniques

摘要

Purpose of Study: Non-invasive laser Doppler fluximetryud(LDF) and laser Doppler imaging (LDI), combined with iontophoresis,udhave been used to study the microcirculation in audrange of clinical conditions including lower limb venous disease.udA prerequisite for an accurate measurement tool is thatudit is reproducible. However, there is currently no literatureudwith respect to the reproducibility of LDF and LDI combinedudwith iontophoresis in the lower limb (in general) and in theudupright position (in specific). Furthermore, the two techniquesudhave been used interchangeably by researchers andudthe association between these two different measurementudmethods has not been explored, nor have the factors thatudaffect them been well described. Thus the aim of this studyudwas to determine the reproducibility of LDF and LDI withudiontophoresis in the lower limb and investigate factors thatudinfluence their clinical application. Procedures: Cutaneousudmicrovascular responses in the lower limb were measured inudthe supine and standing positions using LDF and LDI combinedudwith iontophoretic administration of endothelial-dependentud(acetylcholine, ACh) and -independent (sodium nitroprusside) vasodilators in 25 patients with uncomplicatedudisolated superficial venous incompetence (ISVI) and 26udhealthy controls. Results: Maximum perfusion had the bestudreproducibility assessed by LDF (CV 20.5–24.3%) and LDIud(15.8–17.6%). Both techniques were positively influenced byudiontophoretic dose (e.g. p = 0.0001 for LDF) and the use ofudvasodilator agents (e.g. p = 0.0001 for LDF), but negativelyudinfluenced in the standing position and/or in the presenceudof ISVI (p = 0.0016 and 0.045, respectively, for LDF). There wasuda statistically significant positive relationship between theudtwo techniques, for example ACh maximum perfusion versusudLDF ACh maximum perfusion (r = 0.404, p = 0.016). Conclusions:udBoth techniques are reproducible, in line with similarudstudies undertaken in other areas of the human body,udand provide useful information for the study of the lowerlimb microcirculation. Direct comparison between techniques based on absolute numbers should be avoided andudthe technique choice should be based on individual studyudneeds.