A Case of“De Novo”Aneurysm of Anterior Communicating Artery Formed Two Years and Eight Months after the Initial Cerebral Angiogram

Abstract

We describe a case of de novo aneurysm formed 2 years and 8 months after the initial cerebral angiogram. The patient, a 52-year-old male, suffered from subarachnoid hemorrhage on September 25, 1996. He was admitted to our department two days after onset. He has a past history of cerebral infarction and hypertension. Cerebral angiogram revealed an aneurysm at left A₁-A₂, junction that was not found on his first angiogram. We diagnosed this as a de novo aneurysm and performed an operation on September 30. The ruptured aneurysm was successfully clipped through the left pterional approach. He was discharged from our hospital with no neurological deficits. De novo aneurysms are not common findings and most are formed because of the change of hemodynamics of the circle of Willis after IC occlusion has taken place or IC ligation has been carried out.
Some authors reported the coexistence of this new aneurysm and a persistent primitive artery. In our case, there was no vascular anomaly that influenced the formation of de novo aneurysm nor a history of the operation of other aneurysms. It is very interesting that a de novo aneurysm could be formed within a very short follow-up period as in our case, in which the aneurysm was not accompanied by subarachnoid hemorrhage at the first cerebral angiogram. In this paper we discuss the nature of de novo aneurysm and compare our case with the reported cases.