A preparative technique for morphological analysis of the vessels in head and neck for medico-legal examinations.

The fine-structural analysis of injuries and injury-related damages of the arteries in the head and neck region, such as vital endothelial injuries resulting from death by hanging, is of considerable importance in legal medicine, as it involves numerous forensic problems. The problems and difficulties of vessel preparation, including the occurrence of artefacts, have been widely discussed in medical journals, indicating the necessity for a special method of preparation to be developed. This method has to take individual differences of the autopsy material into consideration, including osmolarity changes caused by hypoxia, and autolysis. The method developed by us and described here meets these conditions. Optimization and standardization of the method was achieved by perfusion fixation of the vascular system in situ. The particular characteristics of the vessels involved made it necessary to open the skull. After removing the upper half of the brain and applying a partially permeable sealing to the skull base, we proceeded with the perfusion, using slightly hyperosmotic perfusion media (450-680 mOsm) via a hydrostatic system, and keeping pressure and flow rates low (max. 65 cm H2O). The perfusion technique we developed, and which is described in detail, has proven suitable for the preparation of other vessels as well, which is demonstrated on the venae cerebri superiores. The method of preparation was designed to provide conditions for a routine application of SEM, LM and TEM for forensic purposes.