De-novo formation of neighboring intracranial aneurysm after spontaneous thrombosis of a ruptured distal anterior cerebral artery aneurysm: A case report and review of the literature

Intracranial aneurysms arise in 1-2% of the population and usually present as hemorrhagic strokes. Spontaneous thrombosis of a ruptured intracranial aneurysm occurs in 1-3% and most commonly in giant aneurysms, with complete thrombosis in just 13-20% of the cases. Thrombosis of smaller aneurysms is rare. Here we present a case of a patient who presented with a ruptured intracranial aneurysm that subsequently thrombosed, discovering a neighboring de-novo aneurysm during follow-up. We hypothesized that after thrombosis, the hemodynamic characteristics that contributed to the formation of the first aneurysm were replicated.

Complete spontaneous thrombosis in unruptured non-giant intracranial aneurysms: A case report and systematic review

BACKGROUND AND AIM

Spontaneous partial or complete thrombosis of saccular unruptured intracranial aneurysm (UIAs) is a known occurrence in giant aneurysms. However, spontaneous complete thrombosis of non-giant aneurysms is a rare event in the natural history of UIAs. The aim of this paper is to report on the cases from literature of complete spontaneous thrombosis with a view to identify possible factors associated with this phenomenon.

MATERIAL AND METHODS

We performed a systematic review of the current literature on spontaneous complete thrombosis of saccular, non-giant, unruptured UIAs, including a case that we treated at our institution. We analysed the possible risk factors for thrombosis, association with ischemic events, rupture and recanalization. We reviewed the possible management's strategies for this group of patients described in literature to date.

RESULTS

We identified 26 patients for a total of 27 thrombosed aneurysms from the literature review (including our case). Thrombosis was prevalent in women, in the anterior circulation and in larger aneurysms. Endovascular events in the parent artery, either spontaneous or iatrogenic, were associated with spontaneous thrombosis in 4 cases. In 47 % of cases an antiplatelet treatment (AP) was introduced. Rupture and recanalization of the aneurysm were observed in 14 % and 33 % respectively. A larger size was the only factor statistically associated with rupture (P = 0041). AP was not statistically associated with recanalization or rupture of the aneurysm.

CONCLUSION

Complete spontaneous thrombosis is not a curative event. Its natural history is associated with recanalization, rupture and ischemic stroke. Conservative treatment with a clinical-radiological follow up and treatment with AP is a safe option for small aneurysms. Definitive aneurysmal exclusion should be considered in medium and large aneurysms due to the significant risks associated with untreated aneurysms.

Central Retinal Artery Occlusion Due to Intraorbital Ophthalmic Artery Aneurysm

A 60-year-old woman experienced sudden onset of vision loss in her right eye. Neuroimaging studies initially were interpreted as tumorous compression of the right optic nerve. On referral to our institution, examination findings were that of a right central retinal artery occlusion (CRAO). Review of the previous imaging studies was consistent with an aneurysm of the intraorbital ophthalmic artery at the origin of the central retinal artery, which was believed to be the cause of the CRAO.

Partial thrombosis of an anterior communicating artery aneurysm prior to endovascular coiling, with intra-procedural distal thrombus embolization

Thromboembolic stroke from migration of thrombus formed in non-giant intracranial aneurysms is a recognized but rare event. We describe a case of partial thrombosis of a 7 mm anterior communicating artery aneurysm, which embolized to the right callosomarginal artery in the brief time interval between two sequential diagnostic angiograms performed as part of elective endovascular coiling, and before any instrumentation had been advanced into the intracranial circulation. To our knowledge, this is the first reported case of aneurysmal thrombus embolization observed angiographically in near real time.