Idiopathic esophageal submucosal hematoma after flow diverter stent placement for an unruptured intracranial aneurysm: illustrative case.

backgroundFlow diverter stent placement for unruptured intracranial aneurysms requires intensive antithrombotic therapy, which can lead to unexpected hemorrhagic complications. However, standard protocols for managing such conditions have not been established. A rare case of idiopathic esophageal submucosal hematoma after flow diverter stent placement, successfully managed with the continuation of antithrombotic therapy, is reported. OBSERVATIONS: A 76-year-old woman had undergone coil embolization 12 years earlier for a ruptured right paraclinoid internal carotid artery aneurysm. Follow-up imaging showed recurrence of the aneurysm, and she was admitted for flow diverter stent placement. She received dual antiplatelet therapy (aspirin and prasugrel) for 2 weeks prior to treatment, along with appropriate systemic heparinization during the procedure. One hour after treatment, she developed severe chest pain. Contrast-enhanced CT imaging showed an esophageal submucosal hematoma without active bleeding. Conservative treatment was started without discontinuing antiplatelet therapy, resulting in the near-complete resolution of the hematoma on CT imaging by day 11, and she was discharged on day 21. LESSONS: Although rare, idiopathic esophageal submucosal hematoma should be considered a potential complication when a patient complains of chest pain after endovascular treatment. When antiplatelet therapy is required and no active bleeding is present, continuation of antiplatelet therapy can be a viable option under careful observation. https://thejns.org/doi/10.3171/CASE25495.