Spontaneous resolution of perforator aneurysms of the posterior circulation.

The authors present the cases of 3 patients with ruptured perforator aneurysms of the posterior circulation. Patients were 39, 55, and 59 years old. None of the patients had relevant past medical or family history. All presented with World Federation of Neurosurgical Societies Grade I and Fisher Grade 2 or 3 subarachnoid hemorrhage. Initial angiography results were normal. A second cerebral angiogram in each case revealed a small (< 3 mm) aneurysm of perforator arteries of the posterior circulation. Patients were successfully managed conservatively. None of the patients developed symptomatic vasospasm, rebleeding, or hydrocephaly. Control angiograms at 3 months showed spontaneous resolution of the aneurysm in all cases. Rupture of perforator aneurysms of the posterior circulation is a rare condition and it may be underdiagnosed because of limitations of imaging techniques. Treatments can lead to complications in highly functional territories and should be considered wisely, especially due to the fact that the causes and natural history of such aneurysms are unknown and spontaneous healing remains a possibility.