Delayed Remote Intracerebral Hemorrhage following Coil Embolization Using a Simple Technique for Ruptured Anterior Communicating Artery Aneurysm: A Case Report of Subarachnoid Hemorrhage.

Introduction: Delayed remote intracerebral hemorrhage (rICH) is a well-established complication following flow diverter placement for intracranial aneurysms, with a reported incidence of 5.7%-8.5%. Although rare, similar events have also been reported after coil embolization, predominantly in cases in which adjunctive techniques are used. We report a case of delayed rICH after coil embolization performed with a simple technique in a patient at high risk of thromboembolism. Case Presentation: A 62-year-old female presented with subarachnoid hemorrhage due to a ruptured anterior communicating artery aneurysm. The patient also had suspected lung cancer and a smoking history. Emergency coil embolization was performed using a simple technique under systemic heparinization and dual antiplatelet therapy. Immediately after the procedure, computed tomography showed no abnormalities; however, a follow-up computed tomography scan performed the next day revealed intracerebral hemorrhage compressing the corpus callosum, remote from the treated aneurysm. No bleeding source was identified angiographically. Elevated D-dimer levels were noted postoperatively. Conclusion: Hemorrhagic transformation of microembolic infarctions is considered a possible mechanism of the bleeding. In this case, multiple risk factors (including subarachnoid hemorrhage, malignancy, smoking, and intensive antithrombotic therapy) may have contributed. Although antithrombotic therapy is essential to prevent thromboembolic complications, clinicians should be aware of the rare risk of delayed rICH even when using a simple technique.