Shrapnel embolization to the non-coronary sinus of Valsalva following blast injury: migration pathways and hemodynamic determinants

Abstract

Mine-blast injuries are among the leading causes of combat trauma and are frequently associated with thoracic involvement. The incidence of cardiac and great vessel injury in blast-related chest trauma may reach 10–40 % among severely injured patients, whereas fragment embolism is reported only sporadically. Even more exceptional are cases when foreign bodies lodge within the sinuses of Valsalva, particularly the non-coronary sinus. Such observations are clinically and pathophysiologically valuable.
The aim – to present a unique clinical case of shrapnel embolization to the non-coronary sinus of Valsalva following blast injury to the chest and to analyze the presumed migration pathway from the pulmonary circulation into the sinus cavity in the context of contemporary concepts of aortic root hemodynamics.
Materials and methods. A 40-year-old serviceman with gunshot–shrapnel injuries to the left hemithorax and lower limb, multiple fragments in the lungs and pleural cavity, and a metallic foreign body in the region of the aortic root was admitted after staged evacuation and treatment. Initial screening included chest radiography and transthoracic echocardiography. The key diagnostic tool was multiphase contrast-enhanced ECG-gated CT (non-contrast chest CT, cardiac CT, and contrast CT angiography of the chest), which localized a 3–4 mm fragment in the area of the non-coronary sinus of Valsalva and assessed the aortic wall. Surgery was performed under cardiopulmonary bypass.
Results. Intraoperatively, a 3 × 4 mm metal fragment was found freely lying within the cavity of the non-coronary sinus of Valsalva, completely covered by fibrin, without any signs of aortic wall penetration or perforation; the pericardium and myocardium were intact. The fragment was removed easily using a neodymium magnet; no reconstruction of the aortic root was required. The postoperative course was uneventful. Serial CT studies allowed reconstruction of the presumed migration route: pulmonary parenchyma/vessels → pulmonary vein → left atrium → left ventricle → ascending aorta, with final trapping of the fragment in the non-coronary sinus by stable recirculating flow patterns.
Conclusions. The case demonstrates an extremely rare form of shrapnel embolization to the non-coronary sinus of Valsalva without aortic penetration. Fragment fixation was driven by aortic root recirculation zones and fibrin coverage, which mimicked an intramural location on CT. Multiphase ECG-gated CT and magnet-assisted fragment removal under cardiopulmonary bypass are effective for diagnosing and treating such complications, highlighting the importance of a multidisciplinary approach in combat thoracic blast trauma.