How to assess post-occlusive reactive hyperaemia by means of laser Doppler perfusion monitoring: application of a standardised protocol to patients with peripheral arterial obstructive disease.

The standardisation of manoeuvres to perform clinically discriminative microvascular flow reserve tests is still poorly developed, as well as the response analysis. The aim of this study was to establish a reproducible analysis method for the post-occlusive reactive hyperaemia (PORH) test measured using laser Doppler perfusion monitoring (LDPM). LDPM data were measured from the PORH response of 24 Fontaine class II-III peripheral atherosclerotic/arterial obstructive disease (PAOD) patients and 30 healthy subjects. The PORH response was recorded from the dorsum of the foot after 3 min of arterial occlusion at the thigh. The resulting tracings were analysed by describing their morphology through five defined parameters: resting flux (RF), time to RF level (tRF), maximum flux (MF) during reactive hyperaemia, time to maximum flux (tMF), and time to half recovery (tHR). While the time parameters were discriminative between patients and controls, flux parameters were not. The time to resting flux (tRF) led to the most discriminative model that correctly predicted 88.5% of the cases. Hence, we concluded that obtaining t(RF) with the presented procedures provides an optimal model to quantify the patient's microvascular condition from the PORH response.