Microcirculation of the ankle after Cryo/Cuff application in healthy volunteers.

The aim of the study was to assess the combination of compression and cryotherapy (Cryo/Cuff ankle device) on parameters of ankle microcirculation in healthy volunteers over 30 min. In 21 volunteers (12 males, 29 +/- 10 years [incl. females], BMI 24 +/- 3) the Cryo/Cuff ankle device (AIRCAST, Summit, NJ, USA) was applied with continuous assessment of parameters of ankle microcirculation, such as tissue oxygen saturation (SO2), relative postcapillary venous filling pressures (rHb), and microcirculatory blood flow at 2- and 8-mm tissue depths during 30 min with the Oxygen-to-see System, a laser-Doppler-spectrophotometry-system (LEA Medizintechnik, Giessen, Germany). Superficial tissue oxygen saturation (SO2, 48 +/- 19 %) immediately dropped to 23 +/- 15 % (-52 %, p < 0.05) within the first 2 min after Cryo/Cuff activation with a consecutive slow decrease to 32 +/- 23 % (- 32 %, p < 0.05 vs. baseline) after 30 min. Deep SO2 (8 mm, 69 +/- 5 %) did not change within 30 min of Cryo/Cuff application (70 +/- 4 %, n.s.). Superficial postcapillary venous filling pressures (61 +/- 17 relative units) showed an immediate and sustained decrease after Cryo/Cuff application within four minutes to 37 +/- 18 relative units (-39 %, p < 0.05). Deep postcapillary venous filling pressures (85 +/- 20 relative units) dropped within the first four minutes of Cryo/Cuff application to 68 +/- 19 relative units (-20 %, p < 0.05). Superficial microcirculatory blood flow (21 +/- 36 relative units) decreased significantly to 7 +/- 5 relative units after 30 min (-69 %, p < 0.05 vs. baseline). Deep microcirculatory blood flow at 8 mm tissue depth (63 +/- 43 relative units) significantly decreased over the 30 min to 39 +/- 23 relative units (-47 %, p < 0.05 vs. baseline). Using the Oxygen-to-see system we could demonstrate significant effects of the Cryo/Cuff device on the ankle level in healthy volunteers with reduced superficial tissue oxygen saturation with preserved deep tissue oxygen saturation, reduced superficial and deep postcapillary venous filling pressures, and reduced superficial and deep microcirculatory blood flow as a function of time. Further clinical studies are mandatory to elucidate the effects of the Cryo/Cuff device on the microcirculatory environment in injured ankles.