BACKGROUND
Penetrating cardiac box injuries risk cardiac, great-vessel, and pulmonary damage and usually present with hemodynamic instability. A knife impaled there in a stable, ambulatory patient is rare and raises decisions about imaging, surgical approach, and safe removal. This report describes such a patient, in whom blade trajectory and the positioning constraints of the impaled object dictated the operative sequence.
CASE REPORT
A 29-year-old woman presented after self-inflicted injury. She was ambulatory and hemodynamically stable, with a knife impaled in the left hemithorax within the cardiac box. High-sensitivity troponin I was markedly elevated. Point-of-care ultrasound showed a left “barcode sign” (pneumothorax) without pericardial effusion; a chest tube was placed. Contrast-enhanced computed tomography (CT) localized the blade tip millimeters from the left hilum, abutting the left atrial appendage and pulmonary artery, without contrast extravasation. Because the tip abutted the hilum and the knife precluded lateral decubitus positioning, median sternotomy exposed the heart and proximal great vessels before the 9-cm blade was withdrawn under direct vision; no bleeding occurred. The pericardium was unpenetrated. Two small epicardial lesions consistent with contusion were found at the apex. Thoracoscopy after extraction confirmed no lung, hilar, or diaphragmatic injury. She was discharged on postoperative day 10.
CONCLUSIONS
In selected stable patients, contrast-enhanced CT trajectory assessment can inform a staged surgical approach sequenced by physiology, trajectory, positioning constraints, and the exposure needed for vascular control. An impaled blade should be removed only in the operating room, under direct vision, and after the structures along its track are exposed.

Keywords: Sternotomy; Thoracic Injuries; Thoracic Surgery, Video-Assisted; Wounds, Stab; Heart Injuries