The likelihood of rupture of unruptured intracranial aneurysms that were less than 10 mm in diameter was exceedingly low among patients in group 1 and was substantially higher among those in group 2. The risk of morbidity and mortality related to surgery greatly exceeded the 7.5-year risk of rupture among patients in group 1 with unruptured intracranial aneurysms smaller than 10 mm in diameter.

In a multicenter study, 120 patients with intracranial aneurysms presenting a high surgical risk were treated using electrolytically detachable coils and electrothrombosis via an endovascular approach. The results of treatment in patients with posterior fossa aneurysms (42 patients with 43 aneurysms) are presented. The most frequent clinical presentation was subarachnoid hemorrhage (24 cases). The clinical follow-up periods ranged from 1 week to 18 months. Complete aneurysm occlusion was obtained in 13 of 16 aneurysms with a small neck and in four of 26 wide-necked aneurysms. A 70% to 98% thrombosis of the aneurysm was achieved in 22 of 26 aneurysms with a wide neck and in three of 16 small-necked aneurysms. One aneurysm could not be treated due to a technical complication. Two cases required postprocedural surgical clipping of a residual aneurysm. One patient (originally in Hunt and Hess Grade V) experienced procedural rupture of the aneurysm requiring an emergency parent artery occlusion. He eventually died 5 days later. Another patient (originally in Grade IV) had coil migration and posterior cerebral artery territory ischemia. A third patient developed a permanent neurological deficit (hemianopsia) after complete occlusion of a wide-necked basilar bifurcation aneurysm. One patient, harboring an inoperable giant basilar bifurcation aneurysm, died from aneurysm bleeding 18 months after partial occlusion. Overall morbidity and mortality rates related to treatment were 4.8% (two cases) and 2.4% (one case), respectively (2.6% and 0% if considering only patients in Hunt and Hess Grades I, II, and III). It is suggested that this technique is a viable alternative in the management of patients with posterior fossa aneurysms associated with high surgical risk. Longer angiographic and clinical follow-up study is necessary to determine the long-term efficacy of this recently developed endovascular occlusion technique. Close postoperative angiographic and clinical monitoring of patients with wide-necked subtotally occluded aneurysms is mandatory to check for potential aneurysmal recanalization, regrowth, and rupture.

This long-term follow-up study of 54 patients clarifies the angiographic predictors of intracranial hemorrhage (ICH) and clinical outcome in individuals with unoperated intracranial dural arteriovenous fistulae (AVF's). All of these patients were examined at the Mayo Clinic between 1976 and 1989, and all available cerebral arteriograms were reviewed by a neuroradiologist. Follow-up information was obtained for 52 patients (96%) until death or treatment intervention, or for at least 1 year after diagnosis, with a mean follow-up period of 6.6 years. Throughout this 6.6-year follow-up period, ICH related to dural AVF occurred in five of the 52 patients, for a crude risk of hemorrhage of 1.6% per year. The risk of hemorrhage at the time of mean follow-up examination was 1.8% per year. Angiographic examination revealed several characteristics that were considered potential predictors of ICH during the follow-up period. Lesions of the petrosal sinus and straight sinus had a higher propensity to bleed, although the small numbers in the series precluded a definite conclusion. A person suffering from a dural AVF with a venous varix on a draining vein had an increased risk of hemorrhage, whereas no hemorrhage was seen in the 20 patients without a varix (p < 0.05). Lesions draining into leptomeningeal veins had an increased occurrence of hemorrhage, although this increased risk was not statistically significant. Patients' initial symptoms were compared to those at follow-up evaluation. Pulsatile tinnitus improved in more than half of the 52 patients, and resolved in 75% of those showing some improvement. Individuals without a sinus or venous outflow occlusion at initial cerebral angiography were more likely to improve or remain stable (89%), whereas patients with an occlusion showed infrequent improvement (11%; p < 0.05).

Extra-axial cavernous hemangiomas are rare lesions previously associated with unacceptable mortality and morbidity rates that precluded surgical resection. The authors analyze the clinical presentation, surgical results, and histology of eight intrasinus cavernous hemangiomas: six located in the cavernous sinus, one in the petrosal sinus, and one in the torcula. Magnetic resonance imaging is the best radiographic test for surgical planning. Successful tumor removal was achieved in six cases with no mortality and low morbidity. In the remaining two patients, only subtotal resection was achieved because of massive hemorrhage in one and the misdiagnosis of a pituitary adenoma leading to a transsphenoidal approach in the other. For hemangiomas arising within the cavernous sinus, extradural removal of the sphenoid bone facilitated preservation of the neurovascular structures. Since the clinical and histological characteristics of these lesions are distinct from intra-axial cavernous hemangiomas, a more appropriate term may be "sinus cavernoma" to indicate that these lesions are primarily intrasinus in origin.

Staged radiosurgery and transarterial embolization provided both rapid symptom relief and long-term cures for patients with cavernous sinus DAVFs. Radiosurgery alone was effective for patients with DAVFs whose arterial supply was not accessible via a transarterial approach, although the time course of symptom improvement was longer, compared with patients who also underwent embolization.