Peripheral Microvascular Resistance as a Predictor for Limb Salvage

Peripheral arterial (below knee popliteal and above the level of ankle distal tibial) thermodilution curves will be obtained. One of the distal tibial arteries (anterior tibial, posterior tibial or peroneal artery, whichever reaches the most distal part of the foot in the run off) will be picked for measurements. At room temperature, 3 ml of saline will be injected brisk manually to determine the peak arterial flow, presented as mean transit time (Tmn). Resting Tmn will be performed and averaged by triplicate measurements at baseline. Then maximal hyperemia will be induced by intra-arterial injection of 30 mg papaverine through the guiding catheter, then 3 ml of saline will be injected to get hyperemic Tmn averaged by triplicate measurements. The guidewire will be kept in a fixed position during the series of measurements. Peripheral vascular flow reserve was calculated as resting Tmn divided by hyperemic Tmn (Fukunaga 2015).