Case Report: Type B intramural aortic hematoma: conservative management or early intervention? A case of rapid progression to aortic dissection.

Background: Intramural hematoma (IMH) is a variant of acute aortic syndrome (AAS) with a highly variable and potentially life-threatening course. Although uncomplicated type B IMH is generally managed conservatively, early disease progression may occur despite optimal medical therapy. Thoracic endovascular aortic repair (TEVAR) represents a safe and effective treatment option in complicated cases, particularly when timely intervention is achieved. Case presentation: A 69-year-old woman presented with acute chest pain radiating to the back. CT angiography revealed a type B IMH extending from the aortic arch to the celiac trunk. The patient was initially managed medically under close surveillance. During hospitalization, she experienced recurrent chest pain and was incidentally diagnosed with a subsegmental pulmonary embolism, for which low-molecular-weight heparin was initiated Initial follow-up imaging showed no disease progression. However, on day 7, worsening symptoms prompted repeat CT, which demonstrated significant IMH progression with early signs of type B aortic dissection. Emergency TEVAR was successfully performed. The postoperative course was uneventful except for a transient post-implantation syndrome. Follow-up imaging confirmed good stent graft positioning and significant reduction of the hematoma. This case highlights the unpredictable evolution of type B IMH and emphasizes the importance of close clinical and radiological surveillance. It also illustrates the therapeutic dilemma posed by concomitant pulmonary embolism requiring anticoagulation.