Internal carotid artery false aneurysm as a fatal complication of transsphenoidal surgery

False aneurysm of internal carotid artery (ICA) is a rare but serious vascular complication observed after transsphenoidal pituitary surgery. Here, we present a 41-year-old woman with a pseudoaneurysm in the ophthalmic1 segment of the left ICA after exoscopic transsphenoidal pituitary surgery. The initially uneventful procedure was complicated by a subarachnoidal hemorrhage 10 days after the surgery, which was confirmed by cranial computed tomography scan. The emergency angiography revealed a pseudoaneurysm of the ophthalmic1 part of the left ICA. Despite repeated endovascular treatments with a flow diverter and coiling, the patient experienced a re-bleeding with consecutive vasospasms, occlusion hydrocephalus and finally bifrontal intracerebral hemorrhage with fatal outcome. As a conclusion in irregular post-operative courses with for example headache, a post-operative magnetic resonance imaging with vessel presentation using TOF sequence and contrast-enhanced MRA might be recommended in order to detect a possible pseudoaneurysm in an early stage.