Maceration

Maceration (from Latin macerare-to soften, to soak), changes caused by the action of water on tissues. M. is possible during life as a result of prolonged contact of the skin with water, for example, the so-called "bath skin" and "laundry skin". In the practice of anatomy institutes, M. is used in the process of processing bones to prepare dry bone specimens. For this purpose, the institutes have special "maceration" rooms equipped with bathtubs in which M. is carried out. After mechanical cleaning of soft tissues, bones are placed for a short time in cold water, where remnants of blood are washed out to avoid pigmentation of the specimens. Then the bones are transferred to closed bathtubs with water heated to a temperature of 40-50°. In these bathtubs, bones remain for 2-3 weeks, after which they undergo further processing (defatting, bleaching). Less frequently, M. is carried out at ordinary temperature over a long period (up to 1 year) or well-cleaned bones are placed in vessels with a warm 5% solution of KOH at a temperature of 45-50°. With this method, the skeleton can be cleaned in 3 hours, after which it undergoes further processing. In histology, methods of M. are used to recognize the form and connection of cells and the ratio of the constituent parts of tissues and organs. For this purpose, water and solutions of various chemical substances are used, for example KOH, NaOH, NH₄OH, HgCl₂ and others; acids: hydrochloric, sulfuric, boric, acetic, picric and others; alcohol, acetone-chloroform, chloral-hydrate and a number of other substances. M. in a corpse begins with processes of imbibition and seepage, then the lifting of the upper layer of the epidermis by transudate and its separation occur. These characteristic changes are clearly expressed in fetuses that died in utero and remained in the amniotic fluid for some time before birth (so-called maceration of the fetus, maceratio fetus). A corpse while in water undergoes the same changes, but complicated by putrefaction. These changes develop as follows: on the corpse in places where the epidermis is particularly thick, for example on the soles, palms, flexor surfaces of the hands and feet, sometimes on the elbows and knees, from the action of water the skin peculiarly thickens, wrinkles and acquires a whitish, chalky color. These changes are formed postmortem from the swelling and impregnation of the epidermis with water and can be obtained experimentally. On a corpse with rough calloused skin, the phenomena of M. develop in a shorter time and much more sharply than on a corpse with delicate, thin skin. The presence of phenomena of M. proves that the corpse was in water, and from the degree of expression of these changes, one can judge the duration of the body's stay in water. First, discoloration, swelling and wrinkling of the skin on the fingertips occurs - approximately after 2-6 hours of the corpse being in water. After 2-5 days, M. spreads to the palmar surface of the hand; then the skin on the back of the hand swells. After 5-8 days, the swollen skin takes on a chalky color and begins to lose its connection with the underlying tissue. Further, this connection is increasingly destroyed, and the epidermis comes off in layers along with epidermal formations. Quite early (after about two weeks), the hairs of the head begin to fall out, which is why it can be taken as bald. Individual hair follicles, still preserved, give the skin the appearance of being pricked with a needle. On the hands, the skin separates after 2-3 weeks along with the nails in the form of "death gloves." After the "gloves" have come off, the hand takes on the appearance of "pampered," and the nail beds have the appearance of polished nails. On the feet, where the epidermis is thicker, these changes occur more quickly. If the feet were in shoes, M. proceeds more slowly. Freezing delays the development of M. The speed of onset of M. depends on the temperature of the water. In summer, the processes of M. occur faster than in winter. According to Devergie, 5-7 hours in summer correspond to 3-4 days in winter time, 24 hours to 3-4 days, 4 days to 15 days, 12 days to 1-1¹/₂ months. In forensic-medical terms, it is important to keep in mind that similar separation of the epidermis, up to the detachment of "gloves," can be caused only by putrefaction and without the action of water, but in such cases, the characteristic wrinkling and condition of the skin, as occurs in maceration, are not observed.