Usefulness of ultrastructure studies for the estimation of the postmortem interval. A systematic review

Establishing the postmortem interval (PMI) is vital in legal medicine as it allows to retrospectively estimate the hour of death, which is essential for the police as a starting point for their inquiries (especially in violent deaths). Ultrastructure studies aimed specifically to detect autolytic changes are scarcely identified in the scientific literature. Moreover, they are performed in a variety of conditions (different temperatures, species, in vitro ÷ in situ, and so on), making the results difficult to interpret for legal medicine purposes. The main aim of this review is to determine the potential usefulness of ultrastructure studies for the estimation of the postmortem interval and to provide a summary of relevant scientific literature in the area, which might be useful as a starting point for more specific and detailed studies in the field. We performed a search on the ISI Thomson Web of Knowledge database using a series of predefined keywords; the articles fulfilling the inclusion criteria were systematically analyzed to identify ultrastructure changes associated with autolysis. Our investigation revealed 20 relevant articles, which detailed ultrastructure changes in the brain, heart, liver, pancreas, kidney, bone, sweat glands, thyroid, skeletal muscle, cartilage and sweat glands. For each organ, we arranged systematically postmortem ultrastructure changes that were described by various authors. Ultrastructure changes appear early and may be useful in determining the time since death in the early postmortem interval. However, most studies published in this area followed methodologies that could not allow a proper reproducibility in forensic circumstances. Therefore, before using ultrastructure for estimating the PMI in practical environments, further studies are needed. They should be performed ideally on human samples, obtained at regular intervals after death, at variable, decreasing temperatures.