Exsanguination from ruptured femoral artery pseudoaneurysm - A fatal complication of groin heroin injection.

Intravenous drug users (IDUs) eventually encounter a common problem- a need to turn to a new vessel to inject drugs. Whether it is because no other spot is available due to scarring or convenience, the groin is the preferred spot for some. Chronic puncture of femoral vessels can lead to a rare but significant complication- femoral artery pseudoaneurysm (FAP). Its fatal consequence- rupture and bleeding is well recognized, but the forensic literature on this subject is limited. We present eight cases of exsanguination due to the ruptured FAP in IDUs who share most or all the following characteristics: long-term heroin use and/or pronounced drug use stigmata, chronic groin injection-related lesions, absence of significant precipitating pseudoaneurysm trauma, and no or minimal concentrations of heroin metabolites in blood. The FAP presentation varied greatly, from palpable fist-sized mass or slight elevation under the skin defect to infundibular arterio-cutaneous fistula that ruptured through the skin induration. In some, surrounding skin or soft tissue showed signs of inflammation but without suppuration. The most prominent FAP characteristic was smooth-surface cavitation on cross-sections. We performed microscopic evaluation in two cases and verified disruption of the artery wall (i.e., pseudoaneurysm) with elements of acute and chronic inflammation and fibrosis; foci of fibrinoid necrosis were noticed on the arterial wall. All subjects were pale, with faint hypostasis and organ anemia, consistent with reported massive hemorrhage. Because such sudden, unwitnessed, and suspicious deaths may raise the question of injury infliction, proper autopsy evaluation is crucial, for which we propose guidelines.