Saccular aneurysm with basal rupture angiographically depicted as an aneurysm with stalk-like narrow neck.

On occasion, the wall of the aneurysm base can be the rupture site of the lesion, which poses a unique challenge for treatment. Although there has already been a report of the angiographic depiction of a basal rupture of a saccular aneurysm by a small outpouching at the aneurysm neck, this is the first report of saccular aneurysms in which a basal rupture was angiographically depicted as a stalk-like narrow neck due to a thrombus sealing the rupture point and occupying the lumen of the aneurysm base. The author reports on 2 such cases: a 49-year-old woman who presented with a basal rupture of a saccular aneurysm arising at the middle cerebral artery bifurcation, and a 44-year-old man who presented with rupture of a saccular aneurysm arising at the junction of the A(2) segment and the anterior communicating artery. In both cases, a pterional craniotomy allowed the surgeon to determine that the base of the aneurysm was ruptured, and he surgically obliterated the aneurysm. Microsuture reconstruction and clipping of the aneurysm neck were successful in obliterating the ruptured aneurysm and avoiding any compromise of the parent artery.