Blood stain pattern interpretation in cases of fatal haemorrhage from ruptured varicose veins.

Blood stain patterns from wounds are determined in part by the nature of the injuries, but also by the types of vessels that have been traumatised. Characteristic spray from arterial injury usually results in a fine projected bloodstain pattern, often found at some distance from the victim. In contrast, venous bleeding tends to be under much lower pressure and less disseminated. However, blood projected from ruptured varicose veins of the lower limbs may also result in a similar pattern of projected, disseminated fine bloodstains. Two cases of lethal haemorrhage from lower leg varicosities are presented involving a 60-year-old woman and an 86-year-old woman. Scene examination in both cases revealed evidence of extensive haemorrhage, with patterns of finely clustered bloodstains on the floors and walls produced by high venous pressures and the small wounds of the acutely ulcerated varicose veins. These features of ulcerated lower leg varicosities simulate the situation that occurs following arterial trauma, where blood may be forced out of a vessel under high pressure through a narrow defect. The fine, dispersed pattern of bloodstains in these cases reflected more the circumstances of the haemorrhage, rather than the intrinsic nature of the vessel of origin. An awareness of this phenomenon may assist in death scene examination when there is extensive haemorrhage with apparent arterial blood spray. An acutely ulcerated lower leg varicosity, with blood spray either on the floor, or at a level that corresponds to the height of the vascular injury, may indicate that the cause of the blood pattern was a lesion with higher than normal pressure venous, and not arterial, haemorrhage.