Penetrating chest trauma in Sauer's danger zone without serious heart or lung damage: An unusual case report

Sauer's danger zone is an area on the anterior chest where trauma is considered to cause heart and macrovascular injury. Herein, we report the case of an injured patient showing evidently fatal findings on chest radiography and computed tomography (CT) presenting almost no actual fatal injuries on surgical examination. The patient was an 86-year-old man who was found by a family member with a 30-cm knife blade stuck in his left front chest (Sauer's danger zone). On chest CT findings, the knife was observed to be inserted through the 4th intercostal space, penetrating the lungs. The tip of the knife appeared to be anchored to the dorsal side of the 9th intercostal space. We found no damage to the heart, only a 2-cm-long and 1-cm-deep cut in the lingular segment area. We confirmed that the amount of bleeding in the inserted drain was an indicator of non-macrovascular injury. In cases of chest trauma, chest tube drainage and hemodynamics should always be observed, and the potential need for emergency surgery should be considered. •The area where there is a risk of cardiovascular injury is called Sauer's danger zone.•The amount of bleeding in the drain was an indicator of non-macrovascular injury.•There is a discrepancy between chest CT and surgical findings.•Chest tube drainage and hemodynamics should always be observed.•The potential need for emergency surgery should be kept in mind.