Tissues under-vacuum to overcome suboptimal preservation

The accuracy of histopathological diagnosis is strictly reliant on adequate tissue preservation, which is completely dependent on pre-analytical variables. Among these variables, the time interval between the end of surgical excision to the onset of fixation (the cold ischemia time) may adversely affect preservation of tissue morphology, influencing the interpretation and reproducibility of diagnosis. During this time interval, the activation of enzymes may produce autolysis and degradation of antigens and nucleic acids, thus potentially affecting immunocytochemical and molecular results. Several studies have described under-vacuum at 4 °C storage of fresh surgical specimens as a safe and reliable method to control cold ischemia and preserve fresh tissues, as well as to standardize fixation times and implement tissue-banking. This review article gives a systematic overview of the advantages and drawbacks of the use of under-vacuum tissue preservation and cooling in surgical pathology, highlighting the impact this procedure may have on diagnostic and experimental pathology. It also documents our experience acquired within daily practice and national and international projects.