Is acute alveolar dilation an indicator of strangulation homicide?

Some cases of suspected homicidal strangulation are difficult to diagnose if the classical injuries of strangulation are few or lacking. The main purpose of this study was to determine if abnormal distension of alveolar airspaces is present in strangulation deaths and whether or not it can be used to support this diagnosis. Another purpose was to see how often the gross examination of the lungs was in agreement with the microscopic examination. The material comprised 33 victims of homicidal strangulation above the age of 15 years, autopsied at the Department of Forensic Medicine in Copenhagen between 1998 and 2007. The results were compared with a control group of the same size, matched for gender and age, all of whom died naturally of cerebral or other neurological causes. The autopsy reports provided the results of the gross examination of the lungs. Regular haematoxylin-eosin stained sections were made from the histological specimens. The microscopic examination was performed by computerized image analysis using stereological methods in an attempt to objectify the observations. The results showed an almost complete concordance between the findings of the gross and the microscopic examination. Stereologically the study showed that the alveoli in the strangulation cases were twice the size of those in the control group which was highly statistically significant concluding that abnormal distension of alveolar airspaces.