Stereological methods for quantitative assessment of hepatic microcirculation

This chapter reviews the current knowledge on healthy and pathological hepatic circulation and microcirculation in animal models used in biomedical research and in human histopathology. To demonstrate the clinical importance of this topic, we focus on blood vessels (particularly microvessels) in liver surgery and in hepatic metastases of colorectal carcinoma. Histological techniques of assessment of healthy and tumourous microvessels are reviewed with focus on the immunohistochemistry on the endothelium, basal lamina and lectin immunohistochemistry. The role of angiogenesis and vascularisation in colorectal cancer and liver metastasis is linked to recent knowledge on proliferation, tumour invasion, metastasis formation, prognostic factors, and scoring systems. In addition to histopathological methods, the three- dimensional imaging of hepatic microvessels using corrosion casts is shown using X-ray microtomography. Stereological methods are demonstrated to quantify the volume, surface, length, numerical density and tortuosity of the microvessels.