Delayed Hemothorax Due to Rupture of a Right Inferior Phrenic Artery Pseudoaneurysm 67 Days After Rib Fractures: A Case Report

Delayed hemothorax after blunt chest trauma usually develops within seven days, and the inferior phrenic artery (IPA) is a rare culprit vessel. We report a case of massive hemothorax that occurred 67 days after rib fractures due to rupture of an IPA pseudoaneurysm. A 73-year-old man was transported in shock with a five-day history of right hypochondrial pain. Non-contrast CT revealed a right pleural effusion with attenuation consistent with blood and multiple fractures of the right 8th-12th ribs, while contrast-enhanced CT demonstrated contrast extravasation adjacent to the right 10th rib. Angiography identified a pseudoaneurysm with active extravasation in a distal dorsal branch of the right IPA, and transcatheter arterial embolization was performed with successful hemostasis. He was admitted to the intensive care unit (ICU) and transfused; after stabilization of his hemodynamics, he was discharged from the ICU on hospital day 2. Percutaneous drainage was subsequently performed for the residual hematoma, and he was transferred to a rehabilitation hospital on hospital day 28. During the course, it was clarified that the multiple right rib fractures had been sustained in a fall 72 days before presentation; therefore, the hemothorax was diagnosed as a delayed hemothorax due to rupture of a right IPA pseudoaneurysm. We experienced a case of delayed hemothorax that developed on day 67 after rib fractures. In delayed hemothorax, the medical history should be traced back several months. Although rare, an IPA pseudoaneurysm can be a life-threatening cause of post-traumatic delayed hemothorax; therefore, in patients with lower rib fractures, an active diagnostic workup is essential.