Large cavernous carotid artery aneurysm with spontaneous thrombosis: is there more to a change in morphology than there seems to be? Illustrative case.

Background: The pathogenesis and endovascular treatment strategy for spontaneously thrombosed unruptured cerebral aneurysms have not yet been comprehensively described.

Observations: The authors reported on a 78-year-old woman who had large bilateral unruptured cavernous carotid artery aneurysms that induced chronic disseminated intravascular coagulation and acquired factor XIII deficiency. The right aneurysm was symptomatic and partially thrombosed. Hemorrhagic diathesis and abnormal values of laboratory data improved after administration of recombinant human thrombomodulin followed by endovascular treatment in which three pipeline embolization devices were deployed for the right aneurysm.

Lessons: To the best of the authors' knowledge, this was the first report of an unruptured cerebral aneurysm leading to coagulation disorders with clinical manifestation that was treated successfully by endovascular intervention after intensive perioperative management.