Spontaneous Regression of an Unruptured and Non-Giant Intracranial Aneurysm

Abstract

It is well known that spontaneous thrombosis in giant cerebral aneurysm is common. However, spontaneous obliteration of a non-giant and unruptured cerebral aneurysm has been reported to be rare and its pathogenic mechanism is not clear. We describe a case with rare vascular phenomenon and review the relevant literatures.

Republished: Spontaneous thrombosis of a basilar tip aneurysm after ventriculoperitoneal shunting

“…This finding is not concordant with other reports that indicate small angle as a factor that favors thrombosis 9. Intuitively, aneurysms with small inclination angles are less exposed to forces exerted along the main direction of blood flow and more prone to thrombosis because of increased turbulence and reduced flow velocity.…”

“…Most reports are in the pediatric population or are cases of giant/fusiform aneurysms 7. In non-giant saccular aneurysms, a large volume to neck ratio8 and small inclination angle between the aneurysm and the parent artery9 have been advocated as factors favoring spontaneous thrombosis.…”

Spontaneous Regression of Aneurysm Remnant after Incomplete Surgical Clipping in a Patient with Ruptured Cerebral Aneurysm

“… 3) 7) Although rare, cases of spontaneous obliteration of aneurysm remnant after surgical clipping of ruptured cerebral aneurysm have been reported. 2) 9) 18) The incidence of aneurysm remnant was 3.8% in a series of 715 aneurysms that were managed using microsurgical techniques. Of 28 aneurysm remnants, 5 aneurysms disappeared in follow-up angiography.…”

Spontaneous thrombosis of a basilar tip aneurysm after ventriculoperitoneal shunting

“…This finding is not concordant with other reports that indicate small angle as a factor that favors thrombosis. 9 Intuitively, aneurysms with small inclination angles are less exposed to forces exerted along the main direction of blood flow and more prone to thrombosis because of increased turbulence and reduced flow velocity. This was not observed in our case, where complete thrombosis occurred after widening of the inclination angle, which increased its exposure to direct inflow from the basilar trunk.…”