Pulmonary micromorphology in fatal strangulations.

Pulmonary histopathology was studied in a group of 106 fatal strangulations including cases of hanging (n = 55; typical, n = 20; atypical, n = 35), ligature strangulation (n = 12), throttling (n = 15), combinations of throttling and ligature strangulation (n = 7) and other compressing force against neck (n = 17). The control group (n = 10) consisted of cases of sudden cardiovascular death. The following results were obtained: intra-alveolar edema of different degree and strong hyperemia could be regularly observed in nearly all cases, especially in fatal hanging (apart from the control cases, in this group the highest mean lung weights were observed). Further frequent histological patterns were perivascular and intra-alveolar hemorrhages, local dystelectasis and focal emphysema. Alterations of the lung vessel contents could be detected in a varying extent: fat embolism (n = 7), mainly of minor degree, embolism of bone marrow tissue (n = 5) and intravascular cell accumulations (n = 22). Embolism of fat and bone marrow tissue was nearly always restricted to cases with accompanying blunt force or resuscitation measures. Whereas only 4 out of 55 cases of hanging revealed intravascular cell accumulations (including different types of leukocytes and immature bone marrow cells), 18 out of 51 cases with the other forms of strangulation exhibited this phenomenon. These accumulations mainly occurred in a discrete and widely scattered manner, appeared in 3 out of 10 control cases (resuscitation measures) as well, and were limited to cases with either protracted courses or accompanying blunt violence. The following conclusions are drawn: the regularly observed general changes of lung microstructure (e.g. edema, hyperemia) are undoubtedly non-specific for strangulation; the alterations of blood vessel contents may serve as a general vitality marker, if resuscitation measures are excluded, but not as an evidence of strangulating force. In cases without signs of blunt force they point to protracted agony courses (shock equivalents).