Occipital dural arteriovenous malformations

Early rebleeding from intracranial dural arteriovenous fistulas: report of 20 cases and review of the literature

OBJECT

In this study the authors sought to estimate the frequency, seriousness, and delay of rebleeding in a homogeneous series of 20 patients whom they treated between May 1987 and May 1997 for arteriovenous fistulas (AVFs) that were revealed by intracranial hemorrhage (ICH). The natural history of intracranial dural AVFs remains obscure. In many studies attempts have been made to evaluate the risk of spontaneous hemorrhage, especially as a function of the pattern of venous drainage: a higher occurrence of bleeding was reported in AVFs with retrograde cortical venous drainage, with an overall estimated rate of 1.8% per year in the largest series in the literature. However, very few studies have been designed to establish the risk of rebleeding, an omission that the authors seek to remedy.

METHODS

Presenting symptoms in the 20 patients (17 men and three women, mean age 54 years) were acute headache in 12 patients (60%), acute neurological deficit in eight (40%), loss of consciousness in five (25%), and generalized seizures in one (5%). Results of the clinical examination were normal in five patients and demonstrated a neurological deficit in 12 and coma in three. Computerized tomography scanning revealed intracranial bleeding in all cases (15 intraparenchymal hematomas, three subarachnoid hemorrhages, and two subdural hematomas). A diagnosis of AVF was made with the aid of angiographic studies in 19 patients, whereas it was a perioperative discovery in the remaining patient. There were 12 Type III and eight Type IV AVFs according to the revised classification of Djindjian and Merland, which meant that all AVFs in this study had retrograde cortical venous drainage. The mean duration between the first hemorrhage and treatment was 20 days. Seven patients (35%) presented with acute worsening during this delay due to radiologically proven early rebleeding. Treatment consisted of surgery alone in 10 patients, combined embolization and surgery in eight, embolization only in one, and stereotactic radiosurgery in one. Three patients died, one worsened, and in 16 (80%) neurological status improved, with 15 of 16 AVFs totally occluded on repeated angiographic studies (median follow up 10 months).

CONCLUSIONS

The authors found that AVFs with retrograde cortical venous drainage present a high risk of early rebleeding (35% within 2 weeks after the first hemorrhage), with graver consequences than the first hemorrhage. They therefore advocate complete and early treatment in all cases of AVF with cortical venous drainage revealed by an ICH.

[Spontaneous epidural hematoma. Report of two cases]

Spontaneous epidural hematomas are rarely described in literature. They are associated with infectious diseases of the skull, coagulation disorders, vascular malformations of the dura-mater and metastasis to the skull. The authors report two cases of spontaneous epidural hematoma of different etiologies, and study parameters of hemostasis.

Treatment for intracranial dural arteriovenous malformations: a meta-analysis from the English language literature

OBJECTIVE

The treatment of intracranial dural arteriovenous malformations (DAVMs) remains problematic. Options include ligature of feeding vessels, endovascular procedures, surgical obliteration, or a combination of the latter two. We conducted a meta-analysis of the English language literature on DAVMs to determine the most effective treatment option related to location and angiographic characteristics.

METHODS

The criteria for inclusion were pre- and post-treatment angiography, a description of the type of treatment, and clinical outcome. The analysis included a total of 258 patients, 248 from a review of 223 published articles and 10 from the authors' series. DAVMs were divided into six categories by location, and the results of treatment were compared based on obliteration rates using chi 2 analysis.

RESULTS

In transverse-sigmoid sinus DAVMs (n = 64), combined therapy (endovascular plus surgical treatment) proved significantly more effective than either therapy alone (P < 0.01). For lesions of the tentorial incisura (n = 66), combined therapy and surgical obliteration alone proved superior to embolization (P < 0.001). For lesions of the cavernous sinus (n = 67), treatment was primarily endovascular, with success rates of 62 to 78% for transarterial and transvenous approaches, respectively. In the anterior fossa (n = 23), surgical obliteration was highly effective, with a success rate of 95%. The small number of cases in both the superior sagittal sinus (n = 28) and middle fossa (n = 10) regions, precluded any statistical analysis. Finally, simple ligature of feeding vessels produced success rates of only 0 to 8% and can no longer be recommended.

CONCLUSION

There is no single ideal treatment for the obliteration of DAVMs. The management of each case is best considered individually. The results of this review serve as a rational starting point for the selection of treatment options.

Intracranial dural arteriovenous malformations: factors predisposing to an aggressive neurological course

The natural history of cranial dural arteriovenous malformations (AVM's) is highly variable. The authors present their clinical experience with 17 dural AVM's in adults, including 10 cases with an aggressive neurological course (strictly defined as hemorrhage or progressive focal neurological deficit other than ophthalmoplegia). Two of these 10 patients died prior to surgical intervention and a third was severely disabled by intracerebral hemorrhage. Six patients underwent surgical resection of their dural AVM, with preparatory embolization in two cases. One patient received embolization and radiation therapy without surgery. Six of the seven cases without an aggressive neurological course were treated conservatively, and the seventh patient underwent embolization of a cavernous sinus dural AVM because of worsening ophthalmoplegia. In order to clarify features associated with aggressive behavior, a comprehensive meta-analysis was performed on 360 additional dural AVM's reported in the literature with sufficiently detailed clinical and angiographic information. The location and angiographic features of 100 aggressive cases were compared to those of 277 benign cases. No location of dural AVM's was immune from aggressive neurological behavior; however, an aggressive neurological course was least often associated with cases involving the transverse-sigmoid sinuses and cavernous sinus and most often associated with cases at the tentorial incisura. Contralateral contribution to arterial supply and rate of shunting (high vs. low flow) did not correlate with aggressive neurological behavior as defined. Leptomeningeal venous drainage, variceal or aneurysmal venous dilations, and galenic drainage correlated significantly (p less than 0.05) with aggressive neurological presentation. The latter three angiographic features often coexisted in the same dural AVM. It is concluded that these features significantly increase the natural risk of dural AVM's, and warrant a more vigilant therapeutic strategy.

Vein of Galen aneurysm associated with dural AVM and straight sinus thrombosis. Case report

A 64-year-old man presented with symptoms of obstructive hydrocephalus secondary to a vein of Galen aneurysm associated with a dural arteriovenous malformation and straight sinus thrombosis. The interrelationship of these lesions and their clinical and radiological features are discussed. It is proposed that in this case sinus thrombosis was the primary event in the subsequent development of the other lesions.

Two cases of dural arteriovenous malformation occurring after intracranial surgery

The occurrence of post-operative dural arteriovenous malformation (AVM) has rarely been proved angiographically. The authors report two such cases: in one, a pure dural AVM was located in the region of the cavernous sinus and in another a mixed pial and dural AVM was found in the posterior fossa. The literature about pathogenesis is reviewed.

Angiographic disappearance of multiple dural arteriovenous malformations. Case report

Angiographic disappearance of two dural arteriovenous malformations (AVM's) in different locations in one case is reported. One of the AVM's involved the right transverse sinus, and the other involved the superior sagittal sinus. The patient's presenting symptoms were due to obstructive hydrocephalus resulting from a small intraventricular hemorrhage that was diagnosed by computerized tomography on admission. The symptoms cleared 25 hours after the ictus in conjunction with improvement of hydrocephalus. The AVM involving the right transverse sinus was supplied by the occipital artery, but ligation of that artery was not successful in eliminating the anomaly. One year later, follow-up angiography revealed disappearance of both dural AVM's.

Dural arteriovenous malformation in the posterior fossa associated with intracerebellar hematoma. Case report

A case of an infratentorial dural arteriovenous malformation associated with an intracerebellar hematoma is reported. This malformation was fed by meningeal branches of the right vertebral artery and was drained exclusively by pial veins in the posterior fossa.

CT demonstration of a dural arteriovenous malformation

A case of dural arteriovenous malformation with intracranial and subdural hemorrhage is presented. The computed tomographic scan with contrast injection demonstrated nodular enhancement adjacent to intracerebral hemorrhage, suggesting an underlying vascular malformation. Angiography confirmed this suggested diagnosis. A brief review of dural AVM is included.

Computerized tomography findings in dural arteriovenous malformations. Report of three cases

Changes in the brain parenchyma and cerebrospinal fluid spaces were demonstrated in three cases of dural arteriovenous malformations by computerized tomography (CT). In various combinations, there were 1) vermiform or patchy enhancement after intravenous contrast infusion, 2) abnormal decreased density mainly in the white matter, 3) local mass effect, 4) hydrocephalus, 5) dilatation of the major venous sinus system, and 6) prominent vascular grooving of the skull inner table. Most of these changes were secondary to raised sinus pressure caused by arteriovenous shunt. It was also demonstrated by serial CT that some elements improved after artificial embolization or surgical excision of the malformations.

Blood supply of acoustic neurinomas

The arterial blood supply of acoustic neurinomas is reviewed on the basis of normal and pathological anatomical findings as well as neuroradiological and intra-operative observations. Available data suggest that, as a rule, the tumour primarily receives blood from the external carotid by way of dural vessels, with the occipital artery playing a prominent role. The cerebellar vessels, including the anterior inferior cerebellar artery, are apparently no more than secondary contributors. In the light of these observations, selective external carotid angiography on the diseased side is recommended in acoustic neurinomas. In hypervascularized neurinomas preoperative embolization of afferent external carotid branches is discussed as a potential supplementary procedure.

Dural arteriovenous malformation associated with subdural and intracerebral hematoma: a CT scan and angiographic correlation

Computed tomography of a case of hemorrhage from a dural arteriovenous malformation depicts an occipital varix with dilated venous channels, an intracerebral hematoma, a subdural hematoma and a subfacial hernation. The angiographic and surgical findings are described.

Spontaneous extradural haematomas

Spontaneous extradural haemorrhage may be due to neighbourhood infections, vascular malformations of the dura mater, and disorders of blood coagulation. Two cases are described here: in one, infection was present; in the other, there was a berry aneurysm of the middle meningeal artery with a small parietal dural angioma. Operation was successful in both patients.

Clinical syndromes of arteriovenous malformations of the transverse-sigmoid sinus

Arteriovenous malformations or fistulae shunting arterial blood from branches of the external and internal carotid and vertebral arteries into the transverse-sigmoid sinus may produce different clinical syndromes. The literature is reviewed with 96 patients including six personal cases. Usually these malformations have a congenital origin and only in 4% of the series was there a previous history of a severe head injury. Clinical groups are defined and the role of angiography assessed. Direct surgical approach with occlusion or removal of the vascular malformation is the treatment of choice. Possible methods of treatment by selective embolization are discussed.

The value of the external carotid circulation in the assessment of intracranial disease

The external carotid circulation often contributes a vascular supply in intracranial disease. Adequate radiological evaluation of this circulation is important and may alter the surgical management in these patients.