Successful lower extremity angioplasty improves brachial artery flow-mediated dilation in patients with peripheral arterial disease

INTRODUCTION: Peripheral arterial disease (PAD) is associated with systemic impaired flow-mediated dilation (FMD) and increased risk for cardiovascular events. Decreased FMD may be caused by a decrease in arterial shear stress due to claudication and inflammation due to muscle ischemia and reperfusion. We assumed that endovascular revascularization of lower limb arterial obstructions ameliorates FMD and lowers inflammation through improvement of peripheral perfusion. METHODS: The study was a prospective, open, randomized, controlled, single-center follow-up evaluation assessing the effect of endovascular revascularization on brachial artery reactivity (FMD) measured by ultrasound, white blood cell (WBC) count, high-sensitive C-reactive protein (hs-CRP), and fibrinogen. We investigated 33 patients (23 men) with chronic and stable PAD (Rutherford 2 to 3) due to femoropopliteal obstruction. Variables were assessed at baseline and after 4 weeks in 17 patients (group A) who underwent endovascular revascularization and best medical treatment, and in 16 patients (group B) who received best medical treatment only. RESULTS: FMD did not differ between group A and B (4.96% +/- 1.86% vs 4.60% +/- 2.95%; P = .87) at baseline. It significantly improved after revascularization in group A (6.44% +/- 2.88%; P = .02) compared with group B at 4 weeks of follow-up (4.53% +/- 3.17%; P = .92), where it remained unchanged. The baseline ankle-brachial index (ABI) was similar for group A and B (0.63 +/- 0.15 vs 0.66 +/- 0.10; P = .36). At 4 weeks of follow-up, ABI was significantly increased in group A (1.05 +/- 0.15; P = .0004) but remained unchanged in group B (0.62 +/- 0.1). WBC counts of the two groups were comparable at baseline (group A: 7.6 +/- 2.26 x 10(6)/mL and group B: 7.8 +/- 2.02 x 10(6)/mL, P = .81). In group A, the leukocyte count significantly decreased after angioplasty from 7.6 +/- 2.26 to 6.89 +/- 1.35 x 10(6)/mL (P = .03). For group B, WBC count did not differ significantly compared with baseline (7.76 +/- 2.64 x 10(6)/mL; P = .94). No effects were observed on hs-CRP or fibrinogen from endovascular therapy. CONCLUSION: Endovascular revascularization with reestablishment of peripheral arterial perfusion improves FMD and reduces WBC count in patients with claudication. Revascularization may therefore have clinical implications beyond relief of symptoms, for example, reducing oxidative stress caused by repeated muscle ischemia or increased shear stress due to improved ambulatory activity.

A quantitative analysis of microcirculation in sore-prone pressure areas on conventional and pressure relief hospital mattresses using laser Doppler flowmetry and tissue spectrophotometry

BACKGROUND Pressure ulcers are associated with severe impairment for the patients and high economic load. With this study we wanted to gain more insight to the skin perfusion dynamics due to external loading. Furthermore, we evaluated the effect of different types of pressure relief mattresses. METHODS A total of 25 healthy volunteers were enrolled in the study. Perfusion dynamics of the sacral and the heel area were assessed using the O2C-device, which combines a laser light, to determine blood flow, and white light to determine the relative amount of hemoglobin. Three mattresses were evaluated compared to a hard surface: a standard hospital foam mattress bed, a visco-elastic foam mattress, and an air-fluidized bed. RESULTS In the heel area, only the air-fluidized bed was able to maintain the blood circulation (mean blood flow of 13.6 ± 6 versus 3.9 ± 3 AU and mean relative amount of hemoglobin of 44.0 ± 14 versus 32.7 ± 12 AU.) In the sacral area, all used mattresses revealed an improvement of blood circulation compared to the hard surface. CONCLUSION The results of this study form a more precise pattern of perfusion changes due to external loading on various pressure relief mattresses. This knowledge may reduce the incidence of pressure ulcers and may be an influencing factor in pressure relief mattress selection.