[A case of polycystic kidney associated with new growth of cerebral aneurysm after aneurysmal operation].

We have encountered a 66-year-old woman with a polycystic kidney (PCK). This was combined with the fact that the new growth of an aneurysm at the left anterior cerebral artery (A2-A3 junction) had ruptured 3 years after an operation for a right IC-PC aneurysm in 1985. The cause of the neogenesis and enlargement of an intracranial aneurysm is important because of the changes in the arterial wall due to congenital factors, hypertension, arteriosclerosis, etc, or hemodynamic stress caused by hypertension. We suspected that intracranial aneurysm formation was caused by hypertension due to PCK and the intracranial aneurysm is explained as being due to maldevelopment. In patients with PCK, it should be kept in mind that intracranial aneurysms may be present, and it is advisable to use cerebral angiography and MRA to see whether this is so or not. It should be also stressed that the control of hypertension is very important for the prognosis of patients with PCK. Not only new growth of cerebral aneurysms but also intracerebral hemorrhage is to be prevented.