Douglas A. Nichols
Jonathan A. Friedman, Bruce E. Pollock and Douglas A. Nichols
✓ This 61-year-old man with a right-sided tentorial dural arteriovenous fistula (DAVF) was initially treated with staged stereotactic radiosurgery and transarterial embolization. Results of follow-up cerebral angiography performed 4 years later demonstrated complete obliteration of the dAVF and development of a previously undetected cerebellar arteriovenous malformation (AVM). The newly diagnosed AVM was treated with repeated stereotactic radiosurgery. This represents the first reported case of the development of a cerebral AVM documented in an adult by serial angiography.
Robert D. Brown Jr., David O. Wiebers and Douglas A. Nichols
✓ 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).
Wouter I. Schievink, David G. Piepgras and Douglas A. Nichols
✓ The authors report a case of a 45-year-old woman with pulsatile tinnitus who was found to have an unusual spontaneous fistula between the petrous internal carotid artery and internal jugular vein. The fistula resolved spontaneously, possibly related to daily manual compression of the ipsilateral common carotid artery. The patient also had a contralateral carotid artery dissection, multiple intracranial arachnoid cysts, and hemifacial atrophy. Her medical history was significant for easy bruisibility, abnormal scarring, and mitral valve prolapse. This association appears unique and may represent a previously undescribed generalized connective tissue disorder.
David G. Piepgras, Vini G. Khurana and Douglas A. Nichols
✓ The authors describe a unique clinicopathological phenomenon in a patient who presented with an unruptured giant vertebral artery aneurysm and who underwent endovascular proximal occlusion of the parent artery followed, several days later, by surgical trapping of the aneurysm after delayed subarachnoid hemorrhage (SAH). The intraoperative finding of a thrombus extruding from the wall of the aneurysm at a site remote from the origin of the SAH underscores the possibility that occult rupture of an aneurysmal sac can occur in patients with thrombosed giant aneurysms.
Michael J. Link, Robert J. Coffey, Douglas A. Nichols and Deborah A. Gorman
✓ Over the past 5 years 29 patients with dural arteriovenous fistulas (AVFs) were treated by the authors using the Leksell radiosurgical gamma knife unit. Within 2 days after radiosurgery, 17 patients with AVFs that exhibited retrograde pial or cortical venous drainage (12 patients) and/or produced intractable bruit (eight patients) underwent particulate embolization of external carotid feeding vessels. The rationale for this treatment strategy was that radiosurgery was expected to cause obliteration of most fistulas after 12 to 36 months. In patients with bruit, ocular symptoms, or in those at risk for hemorrhage, treatment with embolization after radiosurgery kept the fistulas angiographically visible for radiosurgical targeting yet offered palliation of symptoms and temporary, partial protection from hemorrhage during the latency period. In 12 patients, preobliteration embolization immediately reduced (10 patients) or eliminated (two patients) retrograde pial venous drainage. To date, no lesion has hemorrhaged after treatment. Angiography 1 to 3 years posttreatment in 18 patients showed total obliteration of 13 fistulas (72%) and partial obliteration of five (28%). Radiosurgery, followed by embolization when retrograde pial venous drainage, intractable bruit, and/or major external carotid artery supply is present, appears to be a promising treatment for selected patients with symptomatic dural AVFs.
Jonathan A. Friedman, Fredric B. Meyer, Nicholas M. Wetjen and Douglas A. Nichols
Fredric B. Meyer, Daniela Lombardi, Bernd Scheithauer and Douglas A. Nichols
✓ 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.
Kent R. Thielen, Douglas A. Nichols, Jimmy R. Fulgham and David G. Piepgras
✓ The authors report their experience using electrolytically detachable coils for the treatment of residual cerebral aneurysms following incomplete surgical clipping. Eight patients were treated for six anterior and two posterior circulation aneurysm remnants. All patients were referred for endovascular treatment by experienced cerebrovascular neurosurgeons at the authors' institution. Patients underwent follow-up angiography immediately after endovascular treatment. In seven of the eight patients, additional follow-up angiographic studies were obtained at periods ranging from 7 weeks to 2 years posttreatment. The latest follow-up angiograms demonstrated that six of the eight aneurysm remnants were 100% occluded, with near-complete occlusion of the other two aneurysm remnants. There was no permanent neurological or non-neurological morbidity or mortality associated with the treatment. There was no incidence of aneurysm hemorrhage during or after treatment.
Endovascular treatment of cerebral aneurysm remnants following prior surgical clipping can be accomplished with acceptable morbidity and mortality rates. Endovascular coil occlusion can play an important adjunctive role in the treatment of those aneurysms that have been incompletely obliterated by surgical clipping.
Michael J. Link, Thomas C. Schermerhorn, Jimmy R. Fulgham and Douglas A. Nichols
✓ The coexistence of a large intracranial arteriovenous malformation (AVM) and a hypercoagulation disorder is rare. The AVM puts the patient at risk for progressive neurological deficit, seizures, and, most importantly, intracranial hemorrhage. The hypercoagulation disorder may result in an increased risk of stroke. The authors describe a 42-year-old man with a Spetzler—Martin Grade 5 AVM who experienced progressive neurological decline. He was subsequently discovered to have partial thrombosis of the AVM, deep cerebral and cortical venous thrombosis, and a hypercoagulation disorder. Hypercoagulation disorders causing neurological deficits are usually treated with anticoagulant medications; however, this approach was not thought to be safe in the presence of a large AVM. Therefore, the AVM nidus was surgically extirpated and a ventriculoperitoneal shunt was placed to treat the increased intracranial pressure caused by the cortical and deep cerebral venous thrombosis. Subsequently, lifelong oral anticoagulation was prescribed. The patient had a progressive neurological recovery and is now living independently at home. The occurrence of partial or complete spontaneous thrombosis of an AVM nidus should raise the possibility of an underlying hypercoagulation disorder.