Intravitalmikroskopische Analyse der Mikrozirkulation der gesunden menschlichen Leber

Abstract

Disturbances of the hepatic microcirculation following liver resection or transplantation are the main determinants of ischemia and reperfusion (I/R) injury. Current techniques to assess microvascular perfusion clinically are indirect in nature. In contrast, intravital microscopy is the only technique that allows the direct visualization and quantification of microcirculation and additionally enables the simultaneous study of cell-to-cell interactions. However, this method requires fluorescent dyes for contrast enhancement and is usually restricted to small animal studies. The novel technique of orthogonal polarization spectral (OPS) imaging combines illumination of the subject with linearly polarized light and imaging of the microcirculation non-invasively by advanced reflectance spectrophotometry. A total of n patients undergoing partial liver resection for live-donor liver procurement were investigated directly after laparotomy. OPS imaging enabled the assessment of sinusoidal diameters, distances between the sinusoids, functional sinusoidal density, red blood cell velocity within the sinusoids, and the calculation of the volumetric blood flow. This study demonstrates for the first time that the new technology of OPS imaging permits direct visualization of human hepatic microcirculation. The results were considered normal for microvascular perfusion of the human liver. OPS imaging provides unique insights into the physiology of microcirculation during live surgery, which is regularly associated with I/R-induced microvascular injury.