Challenges in the treatment of giant cavernous carotid aneurysm associated with hemophilia A: illustrative case.

backgroundHemophilia A is characterized by a deficiency of factor VIII, leading to severe bleeding disorders. Abnormal blood coagulation can complicate the treatment of cerebral aneurysms. OBSERVATIONS: A 20-year-old man with congenital hemophilia A presented with abducens nerve palsy caused by a giant cavernous carotid aneurysm (CCA). Because of the coagulopathy, simple internal carotid artery ligation was chosen, and the aneurysm initially shrank following treatment. However, it recurred due to collateral arteries from the posterior communicating artery and branches of the external carotid artery. These arteries were occluded using endovascular techniques, resulting in complete obliteration of the aneurysm. LESSONS: To the best of the authors' knowledge, this is the first reported case of treating a giant CCA associated with hemophilia A. In patients with coagulopathy, surgical options are limited, and standard treatments may not achieve a complete cure. Careful consideration of treatment strategies is crucial when managing giant CCA in the context of a coagulation disorder. https://thejns.org/doi/10.3171/CASE24693.