Stereotactic radiosurgery for the treatment of dural arteriovenous fistulas involving the transverse-sigmoid sinus

Multidisciplinary treatment of cavernous sinus dural arteriovenous fistulae with radiosurgery and embolization

OBJECTIVE

With the advent of interventional neuroradiology and stereotactic radiosurgery, dural arteriovenous fistulae are less often managed with open surgery. We evaluated the outcome of dural arteriovenous fistulae of the cavernous sinus treated with a combination of radiosurgery and embolization.

MATERIAL AND METHODS

Twenty dural arteriovenous fistulae located in the cavernous sinus were enrolled in our study. Fifteen patients received X-knife radiosurgery alone and 5 also required embolization, one before radiosurgery and 4 after radiosurgery. The mean volume of the lesions was 2.8 ml (range 0.2-12.6), the corresponding radiation volume was 6.5 ml (range 0.6-24.6), and the conformity index was 2.9 (range 1.8-5.3). The mean peripheral and maximum radiation dose was 17.8 Gy (range 17-20) and 28.3 Gy (range 19-37) Gy, respectively. The clinical and imaging data were analyzed.

RESULTS

The mean follow up period was 29 months (23-39). Seventy-five percent (15/20) of patients receiving radiosurgery alone achieved a symptomatic cure and with additional embolization 90% (18/20) were cured. All patients achieved cure on imaging after radiosurgery alone or in combination with embolization. Abnormal imaging findings were observed in two patients after treatment, one had an intracerebral hemorrhage and the other radiation edema, but both were asymptomatic.

CONCLUSION

With multidisciplinary treatment with combined radiosurgery and embolization, satisfactory results can be achieved for dural arteriovenous fistulae with a low complication rate. In patients with mild symptoms, radiosurgery is the initial treatment option. Embolization should be performed in patients with severe symptoms or who have failed radiosurgery.

Cranial and spinal dural arteriovenous malformations and fistulas: an update

Awareness of a potential arteriovenous fistula is critical for diagnosis of cranial as well as spinal fistulas. The natural history of cranial and spinal dural arteriovenous fistulas has been clarified during the last decade and interdisciplinary therapies have experienced a substantial development recently. The classification of Cognard & Merland is now the most widely accepted one for cranial dural AVF. It is based on the degree of flow reversal in the sinuses and cortical veins and reflects well the natural history of the different lesions and serves as basis for therapeutic indications. Several studies have defined the annual bleeding risk of cranial dural fistulas between 1.8 and 15%, depending on the pattern of venous drainage and initial symptomatology. Surgical, endovascular and radiosurgical methods must be selectively chosen for the treatment. The risk associated with surgical or endovascular treatment of benign fistulas is higher than the risk of eliminating fistulas that have already led to cortical venous reflux. Transvenous endovascular occlusion or surgical disconnection of draining veins is the treatment of first choice for cranial and spinal dAVF with venous flow reversal. Benign cranial dural arteriovenous fistulas are a developing indication for radiosurgery.

Treatment of Intracranial Dural Arteriovenous Fistulas: Current Strategies Based on Location and Hemodynamics, and Alternative Techniques of Transcatheter Embolization

Intracranial dural arteriovenous fistulas (AVFs) can occur anywhere within the dura mater. Patients may be clinically asymptomatic or may experience symptoms ranging from mild symptoms to fatal hemorrhage, depending on the location (eg, cavernous sinus, transverse-sigmoid sinus, tentorium, superior sagittal sinus, anterior fossa) and venous drainage pattern of the AVF. In the past, dural AVFs have been treated with a variety of approaches, including surgical resection, venous clipping, transcatheter embolization, radiation therapy, or a combination of these treatments. Recent developments in catheter intervention now allow most patients to be cured with transcatheter embolization, although stereotactic radiation therapy is demonstrating good results in an increasing number of cases and surgery is still the preferred option in some cases. Familiarity with drainage patterns, the risk of aggressive symptoms, recent technical advances, and current treatment strategies is essential for the treatment of intracranial dural AVFs.

Resection of the transverse sinuses and confluence of sinuses for treatment of multiple dural arteriovenous fistulas

Dural arteriovenous fistulas (DAVFs) occurring simultaneously at two or more separate locations are not frequent. In fact, the incidence of multiple DAVFs is 7 to 8% of all DAVFs. Patients harboring multiple DAVFs have a higher incidence of hemorrhage, venous infarction, and neurological deficits due to a greater frequency of leptomeningeal venous drainage. To the authors' knowledge only a few cases of DAVFs involving both transverse sinuses (TSs) have been reported. These patients underwent various combined treatments (transarterial embolization, transvenous obliteration, surgical isolation, resection, and radiosurgery). Treatments performed that do not include resection of the involved sinuses do not always guarantee a cure. The authors present a patient who harbored multiple DAVFs of the TSs, both distally occluded with secondary reflux into the superior sagittal sinus (SSS), the straight sinus, the deep venous system, and the leptomeningeal veins of both hemispheres. An en bloc removal of the portions including the fistulas of the TSs, the confluence of sinuses, and the distal parts of the SSS, and straight sinus allowed for the patient to be cured. The fact is emphasized that despite the progress of endovascular treatment and radiosurgery this kind of DAVF must be surgically treated. The operation may be complex and dangerous.

Transarterial approach for selective intravenous coil embolization of a benign dural arteriovenous fistula. Case report

Transarterial particulate embolization is indicated for benign intracranial dural arteriovenous fistulas (DAVFs) that have no dangerous venous reflux. This treatment, however, does not cure these lesions. In this case report the authors describe a spontaneously occurring DAVF that was treated by implanting coils through a transarterial microcatheter into the affected venous channel. The channel was separate from the normal dural sinuses. The pathological architecture of the fistula and the usefulness of this approach are discussed.