A Case Series of Anterograde and Retrograde Vascular Bullet Embolization
Background/Introduction: Deaths related to firearms are common within the United States with most cases having conspicuous bullet wounds found at autopsy. Individual gunshot wounds may be perforating, having both entrance and exit wounds, or penetrating, having only an entrance wound, with the projectile remaining within the body. In most cases with penetrating wounds, projectiles are relatively easily found by following the bullet pathway on internal examination. However, vascular embolization of a bullet is an uncommon occurrence that should be suspected with a penetrating bullet wound when there is failure to discover the bullet in the expected region. The occurrence rate is approximately 0.3% in penetrating trauma. Arterial bullet embolization can result from penetrating wounds originating from the left ventricle, pulmonary vein, thoracic aorta, abdominal aorta, and peripheral arteries that occur in most of the cases, while 20% of the cases involve venous embolization. Anterograde movement may be a frequent finding; however, paradoxical bullet emboli, or emboli that occurs against the flow of blood, may occur with the effects of gravity and should be considered as well. Study Purpose: We present details regarding three cases of bullet embolization at autopsy, and discussion will focus on the current literature and review of vascular bullet embolization and the trajectories that may take form. Materials and Methods: The cases are selected from the cases of Dr. Joseph A. Prahlow, a practicing forensic pathologist. The first two cases demonstrate bullet emboli that travel in an anterograde fashion, whereas the final case demonstrates bullet emboli that travel in a retrograde fashion. Case Reports: In the first case, a 10-year-old child is found dead along with his mother and another female in a burning trailer. He is shot beforehand, with radiographic images demonstrating shotgun slugs within the posterior cranial cavity and his right neck. The wound path passes through the scalp, skull, and brain, with a fragment of the bullet subsequently embolizing to his jugular vein. In the second case, a teenage boy dies as the result of complications from a gunshot wound of the trunk, with the injury reportedly occurring one month prior to death. The bullet perforates his aorta, which creates a large hematoma adjacent to the defect in the aorta. The bullet then enters the aorta and embolizes into his proximal left internal iliac artery. The hematoma ruptures into his left chest cavity causing extensive bleeding and death. In the third case, a young man suffers eight gunshot wounds, with one bullet in particular entering his inferior vena cava and embolizing in a retrograde fashion into his hepatic venous system. Discussion/Conclusion: A penetrating bullet generally follows a straight course, either exiting the body or being recovered from the surrounding tissues. Usually, conspicuous bullet wounds are found on external examination of the body. However, vascular embolization of a bullet is an uncommon occurrence that should be suspected with a penetrating bullet wound when there is failure to discover the bullet in the expected region, radiologically or surgically. Depending on the trajectory of the bullet, it may travel in an anterograde or retrograde fashion through the arterial or venous system.