Abstract
During aneurysm surgery, we often encounter small hemispherical bulging on the arterial wall nearby which is extremely thinned at the tip. Since we confirmed that such pathology could be the cause of subarachnoid bleeding in one patient in 1978, we have collected 26 cases of such early aneurysmal change, so-called immature berry aneurysm. In this investigation, we positively operated on those cases in which though the apparent berry aneurysm was not identified on cerebral angiography, CT scan suggested the localization of the source of bleeding.
The subjects included 14 males and 12 females. From the severity on admission, they were not always mild cases, but 38% belonged to grade 3 or 4 on Hunt and Kosnik's classification.
The most common site was on the internal carotid, followed by the middle cerebral artery and the anterior communicating artery.
As the treatment, coating only was undertaken in 10 cases, clipping in nine and clipping plus coating in four. Autopsy was performed in four cases, which revealed basically the same histological change as berry aaeurysm.
In conclusion, in cases of immature berry aneurysm, both the diagnosis and treatment are rather difficult and the prognosis is relatively poor.
