Assessment of macro- and microcirculation in contemporary critical limb ischemia

A paucity of data exists regarding manifestations of macro- and microcirculation in contemporary critical limb ischemia (CLI). The aim of this study was (1) to evaluate the differences in foot circulation based on angiographic findings, (2) to clarify the relationship between macro- and microcirculation, and (3) to investigate the effects of postural changes on micro as well as macrocirculation between the supine position to the dependent position.

A total of 40 critically ischemic limbs in 29 patients were included in this study. Noninvasive evaluation of macrocirculation, based on the ankle brachial index (ABI) and ankle pressure, and microcirculation, using skin perfusion pressure (SPP), was performed in both the supine and dependent positions.

There was no significant difference in macro- and microcirculations between any angiographical involvements. In the supine position, dorsal SPP correlated significantly with ABI (P = 0.021, r = 0.363) and ankle-pressure (P = 0.001, r = 0.495), whereas plantar SPP failed to correlate with ABI (P = 0.198, r = 0.208) or ankle-pressure (P = 0.185, r = 0.214). In the dependent position, however, SPP showed no significant correlation with ABI and ankle pressure. Postural change from the supine to dependent position yielded a significant increase in SPP (dorsal: 37.2 ± 16.2 to 77.9 ± 17.7 mm Hg, P < 0.001; plantar: 33.6 ± 17.3 to 75.7 ± 18.3 mm Hg, P < 0.001) as well as ABI and ankle-pressure (ABI: 0.70 ± 0.35 to 0.78 ± 0.42, P = 0.003; ankle-pressure; 108 ± 61 to 111 ± 60 mm Hg, P = 0.038). The effect of postural change on SPP showed no difference between patients with and without any clinical and angiographical complications.

Of microcirculation assessed, only dorsal SPP correlated significantly with macrocirculation in the supine position. Furthermore, postural change from the supine to dependent position produced a dramatic improvement in microcirculation due to the effects of gravity.