BLAST INJURY AS A CAUSE OF AN AORTIC THROMBUS

Abstract

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: We report a 31-year-old male with a single gunshot wound (GSW) to the left back who developed an aortic thrombosis within twenty-four hours after presentation. Vascular pathology following a penetrating trauma, specifically to the chest, without direct aortic injury is profoundly rare and could cause devastating sequelae. CASE PRESENTATION: A 31-year-old male, with no past medical history, presents with a single GSW to the left back inferior to the scapula. Upon imaging the patient, he was found to have a large left pneumohemothorax, lung laceration, and a retained missile between the descending thoracic aorta and the eighth thoracic vertebral body in the posterior mediastinum. A chest tube (CT) was placed with immediate collection of 1500cc of sanguineous output. After this initial bloody drainage, CT output decreased significantly to less than 150 cc/hour, so no vascular or thoracic intervention was immediately planned. Notably, initial computerized tomography angiogram (CTA) chest and close follow up with a second CTA showed no aortic injury. Repeat CTA chest at 24 hours was performed for monitoring of potential vascular pathology which demonstrated a new nonocclusive thrombus in the descending thoracic aorta adjacent to the bullet fragment which measured 8 x 9 mm. The patient was asymptomatic, however, due to the increased risk of distal embolization, he was taken urgently to the operating room for thoracic endovascular aortic stent placement. The patient recovered well and was discharged. DISCUSSION: Ballistic injury has been studied extensively, especially during wartime. These projectiles cause shockwaves throughout the area of injury that extend beyond the projectile tract and can cause intimal injury of vessel which manifest as thrombus, dissection, or aneurysm formation. With no observed direct aortic injury, the vascular injury is presumed to be secondary to the blast injury from the GSW. We previously presented a case report where a 100% obstructing left anterior descending cardiac artery thrombus was found twenty-four hours after a GSW to the chest, in a young healthy male. This required emergent cardiac catheterization and drug eluting stent placement. This case series suggests that the blast injury from a bullet extends beyond the direct damage from the bullet and careful attention to surrounding vasculature must be observed. CONCLUSIONS: Our case highlights the importance of having high clinical suspicion of tissue injury adjacent to GSW tracts. In this case series, vascular structures were never directly injured, yet vascular pathology was found requiring operative intervention. Shockwaves caused by these projectiles can cause thrombus, dissection, and aneurysm formation when traveling in close proximity to vessels. REFERENCE #1: Reade Michael, Thomas Peter. (2016). Pathophysiology of ballistic trauma. 10.1093/med/9780199600830.003.0339 REFERENCE #2: Eletta, Olanrewaju et al. (2020) A case report of myocardial infarction from a gunshot wound to the chest https://www.sciencedirect.com/science/article/pii/S0012369220324211 REFERENCE #3: Shin EH, Sabino JM, Nanos GP 3rd, Valerio IL. Ballistic trauma: lessons learned from iraq and afghanistan. Semin Plast Surg. 2015;29(1):10-19. doi:10.1055/s-0035-1544173 DISCLOSURES: No relevant relationships by Kevin Dong, source=Web Response No relevant relationships by Lewis Schwartz, source=Web Response No relevant relationships by Amy Stewart, source=Web Response