Microcirculatory assessment of vascular diseases

The term "microcirculation" refers to the terminal vascular network of the body, which includes arterioles, capillaries, venules as well as initial lymphatic vessels. Additionally, it insinuates to their unique function in thermoregulation, fluid balance, maintenance of cellular exchange, and metabolism. Disturbances of microvascular function were identified to precede macrovascular involvement in the presence of cardiovascular risk factors and is the hallmark of terminal disease stages like critical limb or acral ischemia. Nevertheless, despite its obvious significance in vascular medicine assessment of microvascular function became increasingly neglected in the clinical institutions during the last decades and seems to play a subordinary role in medical education. We therefore provide an overview over relevant and clinically practicable methods to assess microcirculation in vascular medicine with critical estimations of their pros and cons and their perspectives in the future.

Noninvasive measurements of tissue perfusion in critical limb ischemia

Critical limb ischemia (CLI) remains a challenge for an interdisciplinary therapeutic team due to chronic nonhealing wounds. Against this background, there is a necessity of quality control after revascularization. Beside the isolated evaluation of the macrocirculation by Ankle-Brachial or Toe-Brachial Index measurements, the microcirculation as an additional important factor of wound healing often remains underestimated. The following article gives an overview about the current investigation methods for noninvasive perfusion control of the CLI patient. Therefore, transcutaneous oxygen pressure (tcpO₂), the “oxygen-to-see” method which is a combination of white light tissue spectrometry and laser-Doppler flowmetry, fluorescence angiography with indocyanine green, and multispectral optoacoustic tomography will be described.