Whether and when unruptured aneurysms or aneurysmal rests following incomplete surgery result in subsequent bleeding are major concerns for neurosurgeons. By calculating the annual growth rate of aneurysms in long-term follow-up angiography (partly supplemented with MR-imaging and/or MR-angiography), we attempted to determine the surgical indications for these aneurysms. Long-term follow-up angiography ranging from one to 20 years was carried out on five patients whose ruptured aneurysms had been incompletely occluded, six patients with multiple aneurysms, of which the ruptured ones had been completely obliterated at operation and the small unruptured aneurysms, missed or misdiagnosed, and eight patients with unruptured aneurysms which were asymptomatic or symptomatic. The correlation of annual aneurysm growth rate to subsequent bleeding was investigated. Four out of six fast-growing aneurysms with high annual growth rates (more than 8% increase per year) resulted in subsequent bleeding whereas none of the fourteen slow-growing aneurysms with low annual growth rates (less than 8% increase per year) led to bleeding (Fisher's exact test; p < 0.01). Hypertension, patient age and aneurysmal location showed no significant correlation to the annual growth rate (Fisher's exact test; p > 0.05). This study suggests that aneurysmal rests after incomplete surgery and missed or misdiagnosed multiple or incidental aneurysms which are fast growing have a high possibility of subsequent bleeding and should be operated on as soon as possible.

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A patient who had undergone ventriculoperitoneal shunting developed upper cervical myelopathy. His CSF pressure was markedly low, and deformation of the spinal cord and shrinkage of the subarachnoid space at the upper cervical level were found in radiologic examinations. Ligation of the shunt tube resulted in almost complete recovery. The effect of excessive drainage may have caused the abnormalities.

An approach which improves on the conventional suboccipital craniectomy was used to explore a jugular foramen, a hypoglossal neurinoma, and a tentorial meningioma. A postero-medial mastoidectomy supplemented by the conventional suboccipital craniectomy made it possible to expose the entire sigmoid sinus. Subsequent medial retraction of the exposed sigmoid sinus and continuous dura mater and the extradural removal of petrous bone around the jugular foramen exposed the whole extracranial portion of the tumours. The tumours were totally removed by this approach in which the extradural route corresponded to the extracranial portion of the tumours and the suboccipital route to the intracranial portion. Facial nerve and hearing disturbances, which are frequent complications of the previous approaches, did not occur in our cases. Providing adequate exposure with simple surgical procedures and showing no adverse postoperative sequelae, this approach is most suitable for surgery upon jugular foramen tumours with extracranial extension.