Successful radiosurgical treatment of a dural arteriovenous malformation: case report

A new subtype of intracranial dural AVF according to the patterns of venous drainage

BACKGROUND AND PURPOSE

A well-known classification of dural arteriovenous fistulas (DAVFs) according to the patterns of venous drainage was described in 1977 by Djindjian, Merland et al. and later revised by Cognard, Merland et al. in 1995. They described 5 types of DAVFs assuming that the type of venous drainage is directly correlated with neurologic symptoms and in particular with hemorrhagic risk. We present a series of cases that combines type IV (DAVF with cortical venous drainage associated with venous ectasia) and type V (DAVF with spinal venous drainage), which we named type IV + V.

MATERIALS AND METHODS

A retrospective study between 2012 and 2020 in 2 Hospitals was performed on patients that met inclusion criteria for a diagnosis of this type of DAVF. Demographics, location, clinical presentation and outcomes of endovascular embolization were studied.

RESULTS

Five (2,3%) patients out of 220 had a type IV + V DAVF. All cases had an aggressive presentation, either subarachnoid hemorrhage, myelopathy or both. All patients were treated with endovascular transarterial embolization achieving complete angiographic occlusion in one session and total remission of symptoms at 3 months.

CONCLUSIONS

This rare type of DAVF, combines two aggressive venous drainage patterns. For that reason, patients with type IV+V DAVF probably have a more aggressive natural history and worst outcome due to risk of intracranial and/or spinal hemorrhage and myelopathy, thus requiring urgent diagnostic and treatment. Larger studies are needed to better understand this type of DAVF.

Brain arteriovenous malformation with transdural blood supply: Current status

Arterial blood supply to a brain arteriovenous malformation (BAVM) is mainly derived from the internal carotid artery (ICA) and vertebral basilar artery (VBA) system. However, in certain cases, arteries supplying the meninges may also contribute to the blood supply of the BAVM, resulting in the formation of a BAVM with transdural blood supply (TBS). To review the current status of BAVM with TBS, a literature search was performed in the PubMed database. Articles were screened for relevance and suitability of data. According to recent studies, the mechanisms by which TBS to a BAVM forms are mainly classified into the congenital and acquired type. BAVM with TBS is common in elderly patients and is characterized by intracranial hemorrhage, epilepsy, chronic headache and increased intracranial pressure. Digital subtraction angiography is the gold standard for diagnosing BAVM with TBS. Superselective angiography is also important. Treatments for BAVM with TBS include surgical resection, endovascular treatment (EVT), stereotactic radiosurgery and combined treatment. Surgical resection is difficult to perform. EVT has become the major therapy for treating BAVM with TBS due to its low procedural invasiveness. Combination of surgical resection and EVT may be a good option. In addition, stereotactic radiosurgery is frequently used as a complementary treatment to surgical and endovascular interventions. The prognosis of BAVM with TBS is not favorable, as the defect involves a complex arterial supply system.

Treating intracranial dural arteriovenous fistulas with gamma knife radiosurgery: A single-center experience

Objective:

We evaluated the effectiveness and safety of gamma knife radiosurgery (GKRS) for the treatment of intracranial dural arteriovenous fistulas (dural AVFs) over the past 10 years.

Materials and Methods:

The records of 21 patients diagnosed with dural AVFs between 2004 and 2014 and treated with GKRS were reviewed retrospectively. Complete obliteration (CO) was defined as total symptom relief plus confirmation through magnetic resonance imaging or conventional angiography.

Results:

The median follow-up was 70.5 months (range 3–136 months). Five patients underwent embolization (2 after GKRS). One patient underwent GKRS twice. The CO rate was 47%, and partial to CO rate was 88%. The complete symptom resolution rate was 77%, and all patients achieved partial to complete symptom resolution. The CO rates for Borden Type I and Type II/III dural AVFs were 66.7% and 25% (P = 0.153), respectively, and complete symptom-free rates were 76.9% and 75.0% (P = 1.000%), respectively. The median duration between initial GKRS and complete symptom resolution was 14.3 months. The median treatment to image-free durations for Borden Type I and Type II/III dural AVFs were 25.9 and 60.4 months (P = 0.028), respectively, and treatment to symptom-free durations were 10.6 and 36.7 months (P = 0.103), respectively. One patient had a recurrent hemorrhage. Two patients experienced brain edema after stereotactic radiosurgery and one patient experienced cystic formation after GKRS. The morbidity rate was 19% (four patients) and there was no mortality.

Conclusion:

Treatment with GKRS for dural AVFs offers a favorable rate of obliteration. Patients with dural AVFs that are refractory or not amenable to endovascular or surgical therapy may be safely and effectively treated using GKRS.

Gamma Knife radiosurgery for the management of intracranial dural arteriovenous fistulas

BACKGROUND

This report presents our 15-year experience with Gamma Knife radiosurgery (GKS) for the treatment of 321 patients with dural arteriovenous fistulas (DAVFs) in different locations.

METHODS

The most common locations of DAVFs were the cavernous sinus (206 cases) and transverse-sigmoid sinus (72 cases), which together accounted for 86.6 % of cases. In all, 54 patients had undergone embolization or surgery prior to radiosurgery, and the other patients underwent GKS as the primary treatment. During GKS, radiation was confined to the involved sinus wall, which was considered the true nidus of the DAVF. Target volume ranged from 0.8 to 52 cm(3). Marginal and maximum doses to the nidus ranged from 14 to 25 Gy and from 25 to 36 Gy, respectively.

RESULTS

The mean follow-up time was 28 months (range 2-149 months). In 264 of 321 patients (82 %) available for follow-up study, 173 (66 %) showed complete obliteration of DAVFs with symptomatic resolution, 87 (33 %) had partial obliteration, 2 (0.8 %) had stationary status, 1 (0.4 %) had progression, and 1 (0.4 %) died from a new hemorrhagic episode. Complications were found in only two (0.8 %) patients, one with venous hemorrhage and one with focal brain edema after GKS.

CONCLUSIONS

GKS is a safe, effective treatment for DAVFs. It provides a minimally invasive therapeutic option for patients who harbor less-aggressive DAVFs but who suffer from intolerable clinical symptoms. For some aggressive DAVFs with extensive venous hypertension or hemorrhage, multimodal treatment with combined embolization or surgery is necessary.

Radiosurgery for arteriovenous malformations

Stereotactic radiosurgery is the term coined by Lars Leksell to describe the application of a single, high dose of radiation to a stereotactically defined target volume. In the 1970s, reports began to appear documenting the successful obliteration of arteriovenous malformations (AVMs) with radiosurgery. When an AVM is treated with radiosurgery, a pathologic process appears to be induced that is similar to the response-to-injury model of atherosclerosis. Radiation injury to the vascular endothelium is believed to induce the proliferation of smooth-muscle cells and the elaboration of extracellular collagen, which leads to progressive stenosis and obliteration of the AVM nidus thereby eliminating the risk of hemorrhage. The advantages of radiosurgery - compared to microsurgical and endovascular treatments - are that it is noninvasive, has minimal risk of acute complications, and is performed as an outpatient procedure requiring no recovery time for the patient. The primary disadvantage of radiosurgery is that cure is not immediate. While thrombosis of the lesion is achieved in the majority of cases, it commonly does not occur until two or three years after treatment. During the interval between radiosurgical treatment and AVM thrombosis, the risk of hemorrhage remains. Another potential disadvantage of radiosurgery is possible long term adverse effects of radiation. Finally, radiosurgery has been shown to be less effective for lesions over 10 cc in volume. For these reasons, selection of the optimal treatment for an AVM is a complex decision requiring the input of experts in endovascular, open surgical, and radiosurgical treatment. In the pages below, we will review the world's literature on radiosurgery for AVMs. Topics reviewed will include the following: radiosurgical technique, radiosurgery results (gamma knife radiosurgery, particle beam radiosurgery, linear accelerator radiosurgery), hemorrhage after radiosurgery, radiation induced complications, repeat radiosurgery, and radiosurgery for other types of vascular malformation.

Management, risk factors and outcome of cranial dural arteriovenous fistulae: a single-center experience

BACKGROUND

The role of endovascular interventions in managing dural arteriovenous fistulas (DAVFs) is increasing. Furthermore, in patients with aggressive DAVFs, different surgical interventions are required for complete obliteration or disconnection. Our objective was to evaluate the management of patients with intracranial DAVFs treated in our institution to identify the parameters that may help guide the long-term management of these lesions.

METHODS

The hospital records of 53 patients with intracranial DAVFs were reviewed. We then conducted a systematic telephone interview to obtain long-term follow-up information.

RESULTS

The main presenting symptoms were tinnitus and headache. Nineteen (35%) patients presented with intracranial bleeding, 84% of patients scored between 0 and 2 using a modified Rankin Scale at the last follow-up visit. Twenty-four patients were treated surgically. Overall postoperative complications occurred in seven (29%) surgically treated patients, but only two patients permanently worsened. For patients with Borden type II and III fistulas, the annual incidence of hemorrhage was 30%. Two patients had late recurrences of surgically and endovascularly occluded DAVFs. Long-term follow-up showed that compared with spinal DAVFs, only 50% of intracranial DAVFs showed complete remission of symptoms, 41% partial remission, 6% no remission and 4% deterioration of symptoms that led to treatment of the DAVF.

CONCLUSION

In general, intracranial DAVFs can be successfully surgically managed by simple venous disconnection in many cases. However, half of the patients do not show complete remission of symptoms. Age and the occurrence of perioperative complication were the most important determinants of outcome.

Cranial dural arteriovenous fistulas: modification of angiographic classification scales based on new natural history data

This article presents a modification to the existing classification scales of intracranial dural arteriovenous fistulas based on newly published research regarding the relationship of clinical symptoms and outcome. The 2 commonly used scales, the Borden-Shucart and Cognard scales, rely entirely on angiographic features for categorization. The most critical anatomical feature is the identification of cortical venous drainage (CVD; Borden-Shucart Types II and III and Cognard Types IIb, IIa + b, III, IV, and V), as this feature identifies lesions at high risk for future hemorrhage or ischemic neurological injury. Yet recent data has emerged indicating that within these high-risk groups, most of the risk for future injury is in the subgroup presenting with intracerebral hemorrhage or nonhemorrhagic neurological deficits. The authors have defined this subgroup as symptomatic CVD. Patients who present incidentally or with symptoms of pulsatile tinnitus or ophthalmological phenomena have a less aggressive clinical course. The authors have defined this subgroup as asymptomatic CVD. Based on recent data the annual rate of intracerebral hemorrhage is 7.4-7.6% for patients with symptomatic CVD compared with 1.4-1.5% for those with asymptomatic CVD. The addition of asymptomatic CVD or symptomatic CVD as modifiers to the Borden-Shucart and Cognard systems improves their accuracy for risk stratification of patients with high-grade dural arteriovenous fistulas.

The role of surgery for high-grade intracranial dural arteriovenous fistulas: importance of obliteration of venous outflow

Object

Surgical intervention may be required if endovascular embolization is insufficient to completely obliterate intracranial dural arteriovenous fistulas (DAVFs). The authors report their 14-year experience with 23 patients harboring diverse intracranial DAVFs that required surgical intervention.

Methods

Between 1993 and 2007, 23 patients underwent surgery for intracranial DAVFs. The following types of DAVFs were treated: superior petrosal sinus (in 10 patients); parietooccipital (in 3); confluence of sinuses and ethmoidal (in 2 each); and tentorial, falcine, occipital, transverse-sigmoid, superior sagittal, and cavernous sinuses (in 1 patient each). In all cases, the authors' goal was to obliterate the DAVF venous outflow by direct surgical interruption of the leptomeningeal venous drainage. Transarterial embolization was used primarily as an adjunct to decrease flow to the DAVF prior to definitive treatment.

Results

Complete angiographic obliteration of the DAVF was achieved in all cases. There were no complications of venous hypertension, venous infarction, or perioperative death. There were no recurrences and no further clinical events (new hemorrhages or focal neurological deficits) after a mean follow-up of 45 months.

Conclusions

The authors' experience emphasizes the importance of occluding venous outflow to obliterate intracranial DAVFs. Those that drain purely through leptomeningeal veins can be safely obliterated by surgically clipping the arterialized draining vein as it exits the dura. Radical excision of the fistula is not necessary.

Distal aneurysm of the rostral duplicate anterior inferior cerebellar artery feeding an associated dural arteriovenous malformation: case report and review of the literature

A rare case of a distal aneurysm of a rostral, duplicate anterior inferior cerebellar artery feeding an associated dural arteriovenous malformation is reported. The patient presented with severe nuchal rigidity after sexual intercourse; no neurological deficit was seen. The aneurysm causing the subarachnoid hemorrhage was wrapped but the arteriovenous malformation was inoperable. An analysis of the literature showed 51 cases of coexisting aneurysms and arteriovenous malformations in the posterior fossa; only three of them had a dural arteriovenous malformation. A 7:3 male predominance was recognized. The mean age at diagnosis was 48.5 years. Ninety-four per cent presented with hemorrhage and 6% with cranial nerve deficit only. The bleeding originated from the aneurysm in 73% and from the arteriovenous malformation in 15%; in 12% the origin of bleeding was not mentioned or could not be identified. Outcome was satisfactory in 76%, poor in 7% and 17% died. Treatment of both lesions should be performed in a one-stage operation if technically feasible. Additionally, radiosurgery to surgically unresectable arteriovenous malformations should be considered in cases where aneurysms are clipped or coiled.

Dural arteriovenous fistula of the anterior cranial fossa associated with a ruptured ophthalmic aneurysm: case report and review of the literature

BACKGROUND

Dural arteriovenous fistula (DAVF) accompanied by intracranial aneurysms is an extremely rare situation.

CASE DESCRIPTION

A 65-year-old man presented with sudden loss of consciousness for about half an hour. Computed tomographic scan of the brain showed subarachnoid hemorrhage. Angiogram revealed an ophthalmic aneurysm. In addition, a DAVF located in the anterior cranial fossa was also found. The ruptured aneurysm was completely occluded by coil embolization and the DAVF of the anterior cranial fossa was treated with gamma knife radiosurgery after an uneventful postoperative course. The patient was managed nonoperatively and discharged with close follow-up.

CONCLUSION

An unusual case of anterior cranial fossa DAVF associated with a ruptured ophthalmic aneurysm is reported. We feel special consideration may be required in deciding the priority of treatment in such cases.

Neurovascular radiosurgery

SUMMARY

This article focuses on the treatment of neurovascular diseases, in particular brain arteriovenous malformations (BAVMs), with radiosurgery. The target group for this review is physicians who manage patients with neurovascular diseases, but are not actively engaged in radiosurgery. Radiosurgery for BAVMs is an established treatment with clearly defined risks and benefits. The efficacy of radiosurgery for dural arteriovenous shunts (DAVSs) is probably similar but the treatment has not yet gained the same acceptance. Radiosurgical treatment of cavernomas (cavernous hemangiomas) remains controversial. Well founded predictive models for BAVM radiosurgery show: * The probability of obliteration depends on the dose of radiation given to the periphery of the BAVM. * The risk of adverse radiation effects depends on the total dose of radiation, i.e. the amount of energy imparted into the tissue. The risk is greater in centrally located lesions. The risk of damage to brainstem nucleii and cranial nerves must be added to the risk predicted from current outcome models. * The risk of hemorrhage during the time span before obliteration depends on the BAVM volume, the dose of radiation to the periphery of the lesion and the age of the patient. Central location is a probably also a risk factor.

Bilateral petrous ridge dural arteriovenous malformations treated by a combination of endovascular embolization and surgical excision. A case report

SUMMARY

We report the first case of bilateral complex petrosal arteriovenous malformations (AVM). The patient was treated by a combination of transarterial embolization and surgical excision on the right-sided AVM, and by transarterial and transvenous embolization on left-sided lesion.

Tentorial dural arteriovenous malformation manifesting as trigeminal neuralgia treated by stereotactic radiosurgery: a case report

BACKGROUND

Tentorial dAVMs as a cause of trigeminal neuralgia are extremely rare. Consensus exists that radical treatment of such high-flow dAVMs should be considered because of their high risk of bleeding. The authors present a case of a 50-year-old man who presented with symptoms of tic douloureux caused by tentorial dAVM, which was treated successfully by SRS.

CASE DESCRIPTION

The patient consulted us with a 1-month history of harboring right trigeminal neuralgia. The cerebral angiography revealed a dAVM in the petrotentorial region and the MRI demonstrated a dilated petrosal venous varix compressing the root entry zone of the right trigeminal nerve. Gamma knife surgery was performed with a marginal dose of 18 Gy and a maximum dose of 30 Gy in a volume of 0.3 mL. The target point of the radiosurgery for this patient was a fistula identified by superselective angiography, enhanced computed tomography, and MRI. Follow-up MRI, 1 year after GKS, showed a thrombosed lesion, and the patient was able to end medication. There was no evidence of recurrence or adverse effects in the 3-year follow-up.

CONCLUSION

Stereotactic radiosurgery can play an effective role as a treatment modality for such unusual dAVMs.

Gamma knife surgery for dural arteriovenous shunts: 25 years of experience

Object

The aim of this study was to assess the clinical efficacy of gamma knife surgery (GKS) in the treatment of dural arteriovenous shunts (DAVSs).

Methods

From a database of more than 1600 patients with intracranial arteriovenous shunts that had been treated with GKS, the authors retrospectively and prospectively identified 53 patients with 58 DAVSs from the period between 1978 and 2003. Four patients were lost to follow-up evaluation and were excluded from the series. Thus, this study is based on the remaining 49 patients with 52 DAVSs. Thirty-six of the shunts drained into the cortical venous system, either directly or indirectly, and 22 of these were associated with intracranial hemorrhage on patient presentation. The mean prescription radiation dose was 22 Gy (range 10–28 Gy).

All patients underwent a clinical follow-up examination. In 41 cases of DAVS a follow-up angiography study was performed. At the 2-year follow-up visit, 28 cases (68%) had angiographically proven obliteration of the shunt and in another 10 cases (24%) there was significant flow regression. Three shunts remained unchanged.

There was one immediate minor complication related to the administration of radiation. Furthermore, one patient had a radiation-induced complication 10 years after treatment, although she recovered completely. There was one posterior fossa bleed 2 months after radiosurgery; a hematoma, as well as a lesion, was evacuated, and the patient recovered uneventfully. A second patient had an asymptomatic occipital hemorrhage approximately 6 months postradiosurgery.

The clinical outcome after GKS was significantly better than that in patients with naturally progressing shunts (p < 0.01, chi-square test); figures on the latter have been reported previously.

Conclusions

Gamma knife surgery is an effective treatment for DAVSs, with a low risk of complications. Major disadvantages of this therapy include the time elapsed before obliteration and the possibility that not all shunts will be obliterated. Cortical venous drainage from a DAVS, a risk factor for intracranial hemorrhage, is therefore a relative contraindication. Consequently, GKS can be used in the treatment of both benign DAVSs with subjectively intolerable bruit and aggressive DAVSs not responsive to endovascular treatment or surgery.

Radiosurgery for dural arteriovenous fistulas

OBJECTIVE

Dural arteriovenous fistulas (DAVFs) comprise 10% to 15% of all arteriovenous malformations. Recent studies have demonstrated promising results when radiosurgery is used for DAVFs. We retrospectively analyzed our patients with DAVFs who received stereotactic radiosurgery with or without embolization.

METHODS

Between 1991 and 2002, 18 patients with 23 angiographically confirmed symptomatic DAVFs underwent gamma knife radiosurgery, either alone (n = 8) or in combination with embolization (n = 10). A retrospective chart review was performed to identify DAVF location, venous drainage pattern, radiosurgery dosimetry, clinical outcomes, and imaging results. The series included 9 men and 9 women with a mean age of 65 (range 50-89) years. Nine patients received particulate, coil, and/or absolute ethanol embolization before radiosurgery, and 1 patient received particulate embolization after radiosurgery. The mean duration of clinical follow-up was 43 (range 2-116) months. The mean margin radiosurgery dose was 20 (range 15-30) Gy.

RESULTS

Nine patients had complete resolution of their presenting symptoms, and 9 patients had resolution of all but 1 of their presenting symptoms. Angiographic follow-up (mean 46 months) was performed on 8 patients demonstrating complete obliteration in all the cases. Seven patients evaluated by magnetic resonance angiography or computed tomography angiography showed no evidence of DAVF (4 patients) or decreased DAVF size (3 patients). After radiosurgery, 1 patient developed a temporary hemiparesis. Two permanent neurological deficits occurred after embolization before radiosurgery. No patient had an intracranial hemorrhage after treatment.

CONCLUSION

Stereotactic radiosurgery provides effective long-term relief of symptoms in selected patients with DAVFs.

Natural history, evaluation, and management of intracranial vascular malformations

Intracranial vascular malformations are seen increasingly in clinical practice, primarily because of advances in cross-sectional brain and spinal cord imaging. Commonly encountered lesion types include arteriovenous malformations, cavernous malformations, venous malformations, dural arteriovenous fistulas, and capillary telangiectasias. Patients can experience various symptoms and signs at presentation. The natural history of vascular malformations depends on lesion type, location, size, and overall hemodynamics. The natural history for each lesion subtype is reviewed, with special consideration of the risk of hemorrhage or other adverse outcomes after the lesion is detected and any known predictors of hemorrhage or other outcomes. In practice, these data are compared with the risk of available treatment options as the optimal management is clarified. A multidisciplinary approach including neurosurgery, radiosurgery, interventional neuroradiology, and vascular neurology is most useful in determining the best management strategy.

Selective disconnection of cortical venous reflux as treatment for cranial dural arteriovenous fistulas

Object. A single-institution series of 119 consecutive patients with a dural arteriovenous fistula (DAVF) and cortical venous reflux was reviewed to assess the overall clinical outcome of multidisciplinary management after long-term follow up. The selective disconnection of the cortical venous reflux compared with the obliteration of the entire DAVF was evaluated.

Methods. Dural arteriovenous fistulas in patients in this series were diagnosed between 1984 and 2001, and treatment was instituted in 102 of them. The outcome of adequately treated patients was compared with that of a control group consisting of those with persistent cortical venous reflux and with data found in the literature. In cases of combined dural sinus drainage and cortical venous reflux, a novel treatment concept of selective disconnection of the cortical venous reflux that left the sinus drainage intact, and thus converted the aggressive DAVF into a benign lesion, was evaluated.

Endovascular treatment, which was instituted initially in 78 patients, resulted in an obliteration or selective disconnection in 26 (25.5%) of 102 cases. In 70 cases (68.6%) the DAVFs were surgically obliterated or disconnected. In six cases (5.9%), patients were left with persistent cortical venous reflux. No lasting complications were noted in this series. Follow-up angiography confirmed a durable result in 94 (97.9%) of 96 adequately treated cases, at a mean follow up of 27.6 months (range 1.4–138.3 months).

Selective disconnection was performed in 23 DAVFs with combined sinus drainage and cortical venous reflux. These patients' long-term outcomes were equal to those with obliterated DAVFs, and the complication rate was lower.

Conclusions. Considering the ominous course of DAVFs with patent cortical venous reflux, multidisciplinary treatment of these lesions is highly effective and the complication rate is low. Selective disconnection provides a valid treatment option of DAVFs with combined dural sinus drainage and cortical venous reflux, as has been shown in cranial DAVFs with direct cortical venous reflux.

Venous congestive encephalopathy related to cranial dural arteriovenous fistulas

Cranial DAVFs present with a wide spectrum of clinical findings from pulsatile tinnitus alone to intracranial hemorrhage and NHND. The neurologic sequelae are a consequence of venous hypertension and venous congestion. DAVFs with CVR can present with or develop a VCE that can be recognized on MR imaging as a diffuse T2 hyperintensity in the deep white matter of the cerebral or cerebellar hemispheres. The T2 hyperintensity has a characteristic peripheral enhancement. The telltale sign on MR imaging is the plethora of prominent pial vessels on the surface of the brain that are the engorged cortical veins participating in the cortical venous reflux. Selective angiography is critical for the accurate assessment of the CVR. DAVFs with CVR require prompt treatment, either endovascular alone or a combination of endovascular treatment and surgery.

Alternative management considerations for ethmoidal dural arteriovenous fistulas

BACKGROUND

Ethmoidal dural arteriovenous fistulas (EDAFs) are an unusual type of intracranial vascular lesion that commonly present with acute hemorrhage. They are often best treated surgically; however, recent endovascular advances raise questions concerning the best therapeutic approach.

METHODS

We present 7 cases of EDAFs managed at this institution over a 6-year period, which demonstrate the broad spectrum of clinical behavior associated with the lesions. Four patients presented with intracranial hemorrhage, 1 patient with rapidly progressive dementia, 1 patient with a proptotic, red eye, and 1 with a retro-orbital headache.

RESULTS

One patient underwent no treatment, 1 underwent embolization alone, 2 underwent embolization and resection, and 3 patients underwent resection alone. There was complete obliteration of the EDAF in all of the patients who underwent surgical resection. Embolization was performed through the external carotid circulation and not the ophthalmic artery. There were no treatment-related neurologic deficits.

CONCLUSIONS

Treatment is best managed with a multidisciplinary approach, which emphasizes complete resection of the lesions with assistance from interventional neuroradiology techniques. However, each patient must be evaluated independently as treatment may vary depending on the angioarchitecture of the lesion.

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

OBJECT

The aim of this study was to assess the efficacy and safety of radiosurgery for the treatment of dural arteriovenous fistulas (DAVFs) located in the region of the transverse-sigmoid sinus.

METHODS

A series of 20 patients with DAVFs located in the transverse-sigmoid sinus, who were treated with gamma knife surgery between June 1995 and June 2000, was evaluated. According to the Cognard classification, the DAVF was Type I in four patients. Type IIa in seven, Type IIb in two, and combined Type IIa+b in seven. Nine patients had previously been treated with surgery and/or embolization, whereas 11 patients underwent radiosurgery alone. Radiosurgery was performed using multiple-isocenter irradiation of the delineated DAVF nidus. The target volume ranged from 1.7 to 40.7 cm3. The margin dose delivered to the nidus ranged from 16.5 to 19 Gy at a 50 to 70% isodose level. Nineteen patients were available for follow-up review, the duration of which ranged from 6 to 58 months (median 19 months). Of the 19 patients, 14 (74%) were cured of their symptoms. At follow up, magnetic resonance imaging and/or angiography demonstrated complete obliteration of the DAVF in 11 patients (58%), subtotal obliteration (95% reduction of the nidus) in three (16%), and partial obliteration in another five (26%). There was no neurological complication related to the treatment. One patient experienced a recurrence of the DAVF 18 months after angiographic confirmation of total obliteration, and underwent a second course of radiosurgery.

CONCLUSIONS

Stereotactic radiosurgery provides a safe and effective option for the treatment of DAVFs involving the transverse and sigmoid sinuses. For some aggressive DAVFs with extensive retrograde cortical venous drainage, however, a combination of endovascular embolization and surgery may be necessary.

Intracranial dural arteriovenous malformations: results of stereotactic radiosurgery in 17 patients

AIM

To assess the efficacy of stereotactic radiosurgery (STRS) for the treatment of dural arteriovenous fistulae (DAVF).

MATERIALS AND METHODS

Between November 1987 and December 1998, 17 patients with a total of 18 DAVF were treated with STRS at the National Centre for Stereotactic Radiosurgery, Sheffield. Clinical and radiological data was collected retrospectively from the case notes and radiological records. Two neuroradiologists classified the pre-STRS appearance of the DAVF using the Borden criteria, and reviewed the follow-up imaging. Up to date follow-up was requested from the GPs and referring consultants.

RESULTS

In retrospect one DAVF had been misdiagnosed and was excluded from the study. The remaining 17 DAVF were located at the tentorium (6), cavernous sinus (3), right parasellar region (1), floor of left middle cranial fossa (1), midline posterior fossa (1), petrous apex (1) and transverse sinus (4). Ten were Borden type I, four were type II, three were type III. Follow-up angiography was available for 13 patients; 10 DAVF were completely obliterated, two showed considerable reduction in size, one showed deterioration. Clinical follow-up was available for 14 of the 16 patients.

CONCLUSION

Stereotactic radiosurgery can successfully obliterate DAVF with few side effects.

Results of combined stereotactic radiosurgery and transarterial embolization for dural arteriovenous fistulas of the transverse and sigmoid sinuses

OBJECT

Most dural arteriovenous fistulas (DAVFs) of the transverse and sigmoid sinuses do not have angiographically demonstrated features associated with intracranial hemorrhage and, therefore, may be treated nonsurgically. The authors report their experience using a staged combination of radiosurgery and transarterial embolization for treating DAVFs involving the transverse and sigmoid sinuses.

METHODS

Between 1991 and 1998, 25 patients with DAVFs of the transverse and/or sigmoid sinuses were treated using stereotactic radiosurgery; 22 of these patients also underwent transarterial embolization. Two patients were lost to follow-up review. Clinical data, angiographic findings, and follow-up records for the remaining 23 patients were collected prospectively. The mean duration of clinical follow up after radiosurgery was 50 months (range 20-99 months). The 18 women and five men included in this series had a mean age of 57 years (range 33-79 years). Twenty-two (96%) of 23 patients presented with pulsatile tinnitus as the primary symptom; two patients had experienced an earlier intracerebral hemorrhage (ICH). Cognard classifications of the DAVFs included the following: I in 12 patients (52%), IIa in seven patients (30%), and III in four patients (17%). After treatment, symptoms resolved (20 patients) or improved significantly (two patients) in 96% of patients. One patient was clinically unchanged. No patient sustained an ICH or irradiation-related complication during the follow-up period. Seventeen patients underwent follow-up angiographic studies at a mean of 21 months after radiosurgery (range 11-38 months). Total or near-total obliteration (> 90%) was seen in 11 patients (65%), and more than a 50% reduction in six patients (35%). Two patients experienced recurrent tinnitus and underwent repeated radiosurgery and embolization at 21 and 38 months, respectively, after the first procedure.

CONCLUSIONS

A staged combination of radiosurgery and transarterial embolization provides excellent symptom relief and a good angiographically verified cure rate for patients harboring low-risk DAVFs of the transverse and sigmoid sinuses. This combined approach is a safe and effective treatment strategy for patients without angiographically determined risk factors for hemorrhage and for elderly patients with significant comorbidities.

Stereotactic radiosurgery and particulate embolization for cavernous sinus dural arteriovenous fistulae

OBJECTIVE

To evaluate the safety and efficacy of stereotactic radiosurgery, either with or without transarterial embolization, in the treatment of patients with dural arteriovenous fistulae (DAVFs) of the cavernous sinus.

METHODS

We reviewed the findings, from a prospectively established database, for 20 patients with cavernous sinus DAVFs who were treated with either radiosurgery alone (n = 7) or radiosurgery and transarterial embolization (n = 13) in a 7-year period. The median follow-up period after radiosurgery was 36 months (range, 4-59 mo).

RESULTS

Nineteen of 20 patients (95%) experienced improvement of their clinical symptoms. Fourteen of 15 patients (93%) experienced either total (n = 13) or nearly total (n = 1) obliteration of their DAVFs, as documented by angiography performed a median of 12 months after radiosurgery. No patient experienced a recurrence of symptoms after angiography showed DAVF obliteration. Two patients developed new neurological deficits after embolization procedures. One patient exhibited temporary aphasia secondary to a venous infarction; another patient exhibited permanent VIth cranial nerve weakness related to acute cavernous sinus thrombosis. Two patients experienced recurrent symptoms and underwent repeat transarterial embolization at 7 and 12 months; both patients achieved clinical and angiographic cures (5 and 10 mo later, respectively). One patient experienced recurrent visual symptoms and underwent transvenous embolization 4 months after radiosurgery.

CONCLUSION

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.

Arteriovenous fistula with associated aneurysms coexisting with dural arteriovenous malformation of the anterior inferior falx. Case report and review of the literature

This 24-year-old man presented with an unusual case of a high-flow arteriovenous fistula (AVF). This lesion was similar to giant AVFs in children that have been previously described in the literature. In patients in whom abnormalities of the vein of Galen have been excluded and in whom presentation occurs after 20 years of age, a diagnosis of congenital AVF is quite unusual. The fistula in this case originated in an enlarged callosomarginal artery and drained into the superior sagittal sinus via a saccular vascular abnormality. Two giant aneurysmal dilations of the fistula were present. In an associated finding, a small falcine dural arteriovenous malformation (AVM) was also present. Arterial supply to the AVM arose from both external carotid arteries and the left vertebral artery, with drainage through an aberrant vein in the region of the inferior sagittal sinus into the vein of Galen. Craniotomy with exposure and trapping of the AVF was performed, with subsequent radiosurgical (linear accelerator) treatment of the dural AVM. Through this combination of microsurgical trapping of the AVF and radiotherapy of the dural AVM, an excellent clinical outcome was achieved.

Dural arteriovenous malformation in the anterior cranial fossa

Two cases of dural arteriovenous malformation (AVM) at the base of the anterior cranial fossa are described. In both cases an intracerebral hematoma following the rupture of the AVM was the first indication of the disease. In one case, the malformation was supplied both by the anterior ethmoidal artery and frontopolar artery draining into the superior sagittal sinus. In the second case, the right anterior ethmoidal artery with draining veins into the superior sagittal sinus and sphenoparietal sinus was the feeding vessel. Surgical evacuation of the hematoma and excision of the malformation was performed on both patients. The typical clinical signs and radiological findings are described. A review of the pertinent literature is given.

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.

Direct packing of the isolated sinus in patients with dural arteriovenous fistulas of the transverse-sigmoid sinus

OBJECT

The goal of this study was to evaluate the efficacy of direct packing of the isolated sinus (occluded both distally and proximally) in patients with dural arteriovenous fistulas (AVFs) of the transverse-sigmoid sinus.

METHODS

Eight patients were included in this study. There were seven men and one woman, ranging in age from 47 to 75 years (mean 60.4 years). Five patients presented with intracranial hemorrhage or venous infarction, one with convulsions, and two with pulsatile tinnitus. Prominent retrograde cortical venous drainage due to sinus isolation was angiographically demonstrated in all patients. All patients were treated by a small craniotomy and direct sinus packing with microcoils; the procedure was performed with the aid of digital subtraction angiography. Five patients were pretreated with transarterial embolization to reduce arterial inflow before the procedure, and intrasinus pressure and sinus blood gases were monitored throughout the operation. Postsurgery, the dural AVF was completely obliterated in all patients. The sinus pressure was 29 to 58% of systemic blood pressure, and sinus blood gas levels were purely arterial before packing. There was no morbidity related to direct sinus packing; however, one patient died as a result of acute myocardial infarction. Over a follow-up period ranging from 1 to 5 years, a faint asymptomatic dural AVF recurred in one patient on the cortex adjacent to the occluded sinus but regressed spontaneously within 1 year.

CONCLUSIONS

Direct sinus packing was found to be highly effective for the treatment of dural AVFs that empty into the isolated sinus. Measurement of changes in sinus pressure and sinus blood gas levels was useful for monitoring the progress of direct sinus packing.

The role of radiosurgery and particulate embolization in the treatment of dural arteriovenous fistulas

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.

Management of tentorial dural arteriovenous malformations: transarterial embolization combined with stereotactic radiation or surgery

The clinical, anatomical, and radiological features of nine cases of tentorial dural arteriovenous malformations (AVM's) are presented, and 45 reported cases are reviewed. Unlike dural AVM's of the transverse sigmoid and cavernous sinuses that usually have a benign natural history, dural AVM's of the tentorium typically present with hemorrhage or progressive neurological deficit. In this series, patients ranged in age from 52 to 72 years and included five men and four women. These patients presented with subarachnoid hemorrhage, parenchymal hemorrhage, brainstem dysfunction, cerebellar signs, and obstructive hydrocephalus. Malformations were fed principally by the meningohypophyseal trunk, branches of the middle meningeal artery, and the occipital artery. Venous drainage was uniform through the cortical veins (predominantly the mesencephalic, petrosal, and cerebellar veins). Eight of the nine patients had an associated venous aneurysm(s); two had more than one venous aneurysm, and two patients had a vein of Galen aneurysm associated with the tentorial dural AVM. Eight of nine patients improved after treatment, including four patients with complete obliteration of the dural AVM. Based on our experience, we have developed a treatment protocol for tentorial dural AVM's that uses transarterial embolization followed by direct microsurgery or stereotactic radiation. These therapies, applied in a staged manner, have proven safe and relatively effective for the treatment of dural AVM's.

Dural arteriovenous malformations in the anterior cranial fossa

Two cases of dural arteriovenous malformation (DAVM) fed by the anterior ethmoidal artery in the anterior cranial fossa are reported, one of them examined by magnet resonance imaging (MRI). Only one other case with MRI findings so far has been published. Fourty-eight previously reported cases are reviewed. One of our patients presented with subdural haematoma (SDH) without subarachnoid or intracerebral haemorrhage. The other patient had a nasal bleed without any neurological manifestations. In comparison with previously reported cases, the clinical manifestation of our cases is infrequent (1 patient with nasal bleed, and 2 patients with pure SDH that is 2 and 4%, respectively, in the literature). Feeder was the anterior ethmoidal artery either unilateral or bilateral. Drainage of DAVMs was through a markedly dilated vascular sac into the superior sagittal sinus (SSS). The high incidence of haemorrhage from DAVM in the anterior fossa is related to this vascular sac. Magnetic resonance imaging (MRI) showed a flow void area in the left frontal region on T 1-weighted images in one case. These cases were treated by surgical excision of the malformation with good results. Aetiology, clinical presentation, and treatment of these rare DAVMs in the anterior cranial fossa is discussed.