Three-dimensional rotational angiography in the assessment of the angioarchitecture of brain arteriovenous malformations.

BACKGROUND AND PURPOSE: The angioarchitecture of brain arteriovenous malformations (BAVM) still remains a complex subject of study despite advances in medical imaging techniques. For this reason, the present study aimed to assess whether or not 3D rotational angiography (3DXA) might improve the assessment of BAVM. PATIENTS AND METHODS: Included prospectively were 72 patients who had undergone conventional digital subtraction angiography (DSA) and 3DXA for pretherapeutic assessment of BAVM prior to radiosurgery. Dimensional criteria, arterial-feed patterns, venous drainage, points of weakness and vascular densities (VD) of the nidus and shunt zone were studied. RESULTS: 3DXA detected all arteriovenous shunts by revealing abnormal venous enhancement. Post-processing tools similar to CT and MRI may also be used to make complex 3D reconstructions. In addition, the technique provided significant help for volumetric estimations, extraction of arterial feeders and origins of draining veins, and analysis of the 3D conformation of the nidus. Furthermore, 3DXA detected significantly more points of weakness, such as intranidus aneurysms and venous anomalies (P<0.005). In 65% of cases, a gradient of vascular enhancement intensity was found between the arteries and draining veins surrounding or comprising the nidus. VD, or the percentages of space occupied by the enhanced vascular elements, was evaluated in both the nidus and shunt zone. VD in the shunt zone was highest in untreated patients with no history of bleeding (P<0.005). CONCLUSION: 3DXA offers a useful approach to BAVM exploration and can improve our knowledge of lesional angioarchitecture, necessary for the planning of therapeutic strategies.

[Optical coherence tomography in following up papilledema in idiopathic intracranial hypertension treated with lateral sinus stent placement]. / Évolution en tomographie par cohérence optique de l'œdème papillaire dans l'hypertension intracrânienne idiopathique traitée par mise en place de stent endosinusien du sinus latéral.

OBJECTIVE: To quantify the course of papilledema using the OCT 3 Stratus (Carl Zeiss Meditec, Dublin, CA, USA) after lateral sinus stent placement in patients with idiopathic intracranial hypertension (IIH). METHODS: Ten consecutive patients with a diagnosis of IIH underwent OCT examination before and after lateral sinus stenting, between March 2006 and April 2008, in Timone Hospital's Ophthalmology Department (Marseille, France). All patients had criteria for IIH (International Headache Society, 2004) and sinus abnormalities were diagnosed using three-dimensional rotational gadolinium-enhanced MR venography. In all cases, a direct retrograde cerebral venography with manometry was performed. We used the Cordis PRECISE® RX Nitinol Stent system (ref. 10136245-3, Johnson & Johnson), 30-40 mm in length and 8 mm in diameter, all placed by a single operator via a femoral venous puncture. For each eye, the mean retinal nerve fiber layer thickness was noted using the RNFL Thickness (3.4) strategy, before stenting, and three times after stent placement. The other parameters considered were age, sex, weight, height and body mass index. RESULTS: A significant decrease in retinal nerve fiber layer thickness was observed after stent placement. This parameter was considered normal 3 months after stent placement for eight of ten patients. CONCLUSION: Even though this pathology remains misunderstood, we observed a significant decrease in papilledema in IIH after lateral sinus stent placement, suggesting that high intracranial venous pressure could play a role in this pathology.

[Treatment of grade 0 intracranial aneurysms: Retrospective study of 79 cases]. / Traitement des anévrismes intracrâniens grade 0 : étude rétrospective portant sur 79 patients.

AIM: Without precise international recommendations, despite the advances of the ISUAA study, the superiority of microsurgery or endovascular treatment for unruptured intracranial aneurysm (UIA) over the natural history of this disease has not been proved. In this context, the authors evaluate their experience with the aim of assessing the results and risks of the different therapeutics and comparing them with the natural risk of this disease. MATERIAL AND METHOD: From January 1993 to July 2000, 79 patients harboring 110 UIAs were treated. These patients were divided retrospectively into two groups. Group A included 45 operated patients. Group B included 37 patients treated with endovascular coiling. The therapeutic choice was not randomized and was approved by a multidisciplinary neurovascular staff. RESULTS: The two populations were homogeneous in terms of age and sex. In group A, 12 patients presented early complications (26.6 %), with one death. In group B, 15.6 % of the patients presented an ischemic complication. After 1 year of follow-up, morbidity was 11.4 % in group A and 4.8 % for group B. Angiography found a partial recanalization in 12.5 % of the operated patients and in 33 % of the patients treated with endovascular coiling. DISCUSSION: Many factors are involved in the therapeutic decision: UIA location and size and individual risks. Progress in both surgery and interventional neuroradiology has led to good results conforming with the data reported in the literature but does not demonstrate the superiority of one technique over another.

[Imaging of brain tumors in children]. / Imagerie des tumeurs cérébrales de l'enfant.

Few studies exist in the literature on pediatric brain tumors examined with advances MRI techniques. The aim of this review is to try to find out some specific tissular characteristics of the main cerebral tumors encountered in children, especially through diffusion imaging, perfusion imaging and proton magnetic resonance spectroscopy (MRS). However, hemispheric cerebral tumors are not as common as in the adult population.

Endovascular treatment of idiopathic intracranial hypertension: clinical and radiologic outcome of 10 consecutive patients.

OBJECTIVE: To explore the relation between venous disease and idiopathic intracranial hypertension. BACKGROUND: Optic nerve sheath fenestration and ventricular shunting are the classic methods when medical treatment has failed. Idiopathic intracranial hypertension is caused by venous sinus obstruction in an unknown percentage of cases. Recently, endoluminal venous sinus stenting was proposed as an alternative treatment. METHODS: Ten consecutive patients with refractory idiopathic intracranial hypertension underwent examination with direct retrograde cerebral venography and manometry to characterize the morphologic features and venous pressures in their cerebral venous sinus. All patients demonstrated morphologic obstruction of the venous lateral sinuses. The CSF pressure was measured in all patients. The CSF pressure on lumbar puncture ranged from 27 to 45 mm Hg with normal composition. All patients had headache, and visual acuity loss was noted in eight patients. Funduscopic examination demonstrated papilledema for all patients. All patients had stenting of the venous sinuses. Intrasinus pressures were recorded before and after the procedure and correlated with clinical outcome. RESULTS: Intrasinus pressures were invariably reduced by stenting. For headache, six patients were rendered asymptomatic, two were improved, and two were unchanged after venous sinus stenting for a mean (+/- SD) follow-up of 17 +/- 10.1 months (range 6 to 36 months). Papilledema disappeared in all patients. In all cases, CSF pressure was normalized at 3-month follow-up. In all patients, direct retrograde cerebral venography or multidetector row CT angiography was performed at 6-month follow-up and demonstrated the absence of stent thrombosis. CONCLUSION: The importance of venous sinus disease in the etiology of idiopathic intracranial hypertension is probably underestimated. Patients with idiopathic intracranial hypertension in whom a venous sinus stenosis is demonstrated by a noninvasive radiologic workup should be evaluated with direct retrograde cerebral venography and manometry. In patients with a lesion of the venous sinuses who experienced medical treatment failure, endovascular stent placement seems to be an interesting alternative to classic surgical approaches.

[Endovascular treatment of idiopathic intracranial hypertension. Analysis of eight consecutive patients]. / Traitement endovasculaire de l'hypertension intracrânienne bénigne étiquetée "idiopathique". Analyse de huit cas consécutifs.

INTRODUCTION: Optic nerve sheath fenestration or ventricular shunting are classically proposed after failure of medical treatment. Idiopathic intracranial hypertension is caused by venous sinus obstruction in an unknown percentage of cases. Recently, endoluminal venous sinus stenting was proposed as an alternative treatment. PATIENTS AND METHOD: Between September 2003 and December 2004, eight consecutive patients with a diagnosis of idiopathic intracranial hypertension underwent MRI venography and direct retrograde cerebral angiography. RESULTS: There were five females and three males aged 22 to 55 years. All patients had vision disorders. The cerebrospinal fluid pressure ranged from 27 to 45 mmHg with normal composition. All patients presented at least one sinus stenosis. Endovascular stenting of the stenotic venous sinus was performed under intravenous heparin administration. Anti-platelet therapy was administered for 3 months post treatment. Intra-sinus pressures were invariably reduced by stenting. Mean follow-up was 18 months. All patients improved clinically. The cerebrospinal fluid pressure had normalized at 3-month follow-up in all patients. In all patients, multidetector row CT-angiography or MRI venography was performed at 3-, 6- and 12-month follow-up and demonstrated the patency of the stent. DISCUSSION: The importance of venous sinus disease as a cause of idiopathic intracranial hypertension is probably underestimated. Patients with idiopathic intracranial hypertension should be evaluated with direct retrograde cerebral venography and manometry. In patients with venous sinus lesions, treatment by an endoluminal venous sinus stent is a safe and effective alternative for amenable lesions.

Embolization-driven occlusion of the abdominal aortic aneurysmal sac as the basis of prevention of endoleaks in a new swine model.

OBJECTIVES: To assess the effect of a new polymer in embolization of endoleaks using an animal model. METHODS: A modified aortic stent-graft was placed in 20 pigs. Embolization was performed at the time of graft insertion with non-cytotoxic n-butyl-2-cyanoacrylate-metacryloxysulpholane and lipiodol (0.2:0.8ratio, 2 ml). Angiography, scanning electron microscopy and immuno-histochemistry were obtained at day 0, 1 week and 3 months. RESULTS: In control animals both type I and II endoleaks were demonstrated. In treated animals, neither type-I nor type-II endoleaks were observed and a fibro-proliferative response was demonstrated within the aneurysm thrombus. CONCLUSIONS: Host vascular responses govern the fate of the excluded aneurysm. Embolization of the sac and feeding arteries with non-cytotoxic glue sealed all occlusions by stimulating a massive restenosis-like process.

Retrospective study of 77 patients harbouring lumbar synovial cysts: functional and neurological outcome.

BACKGROUND: Synovial cysts represent an uncommon and probably underestimated pathological entity of the degenerative lumbar spine. The authors report a retrospective analysis of the clinical presentation, radiological studies and operative findings in 77 patients surgically treated for symptomatic lumbar synovial cysts at their institution. MATERIALS AND METHOD: Between January 1992 and June 1998, a total of 77 patients presenting with symptomatic lumbar synovial cysts were operated on in the author's department. Operative procedure, complications, results and pathological findings were correlated with preoperative assessment. There were 41 men and 36 women with an average age of 63 years (range 44-90 years). RESULTS: On the basis of their symptom complex on presentation, two populations were identified: patients who presented with a single radicular pain (group I = 51 patients), and patients who presented with bilateral neurogenic claudication (group II = 26 patients). Neurological examination on presentation demonstrated motor deficit (12%), sensory loss (26%) and reflex changes (35%). Degenerative disc disease and facet joint osteoarthritis was a frequent finding in patients with pre-operative MRI. Facet joint orientation was >45 degrees in 76.6% of patients. Preoperative spondylolisthesis was found in 48% on radiological studies. All the patients were treated surgically with resection of the cyst. No fusion was performed as a first line procedure. However subsequent fusion was necessary in one patient who developed symptomatic spondylolisthesis. Mean follow-up period was of 45 months ranging from 18 to 105 months. Only one recurrence occurred during the follow-up period. An excellent or good functional outcome was seen in 97.4% of cases, and 89% of the patients with motor deficit recovered. CONCLUSIONS: Surgical resection of lumbar synovial cysts is an effective treatment associated with very low morbidity. Synovial cysts are associated with increased grade and frequency of facet joint asteoarthritis but not with increased grade or frequency of degenerative disc disease compared with patients without cysts. In the author's opinion, at the present time, there is no reliable criterion which allows the development of a symptomatic spinal instability to be predicted in patients with a preoperative spondylolisthesis and therefore fusion as a first line procedure is still debatable.

[Endovascular treatment of benign intracranial hypertension by stent placement in the transverse sinus. Therapeutic and pathophysiological considerations illustrated by a case report]. / Traitement endovasculaire d'un syndrome d'hypertension intracrânienne bénigne par mise en place d'un stent dans le sinus lateral. Considerations thérapeutiques et physiopathologiques à propos d'un cas.

We report a case of benign intracranial hypertension in a 31-year-old man treated by endovascular stent placement in the right transverse sinus. The patient presented with a typical benign intracranial hypertension syndrome. Ophthalmologic findings showed bilateral papilledema with a 7/10 loss visual acuity loss in the right eye and 2/10 in the left eye. At lumbar puncture, cerebrospinal fluid (CSF) pressure was 40 mmHg. Magnetic resonance imaging (MRI) showed slit ventricles and dilatation of optic nerve sheaths. optiques. After failure of medical treatment, the patient was referred to our neurosurgical department for therapeutic decision. Direct retrograde cerebral venography showed predominant cerebral venous drainage via the right transverse sinus which exhibited stenosis in its proximal third. Mamometry revealed a 25 mmHg pressure gradient across the point of stenosis. Due to possible venogenic benign intracranial hypertension, endovascular stent placement was proposed and accepted by the patient. At 3 months follow-up, the patient was symptoms free, papilledema had disappeared and visual acuity was 10/10 on both eyes. CSF pressure on lumbar puncture was 11 mmHg. The pathophysiological aspects and therapeutic management of this pathology illustrated by this are discussed along with a careful and exhaustive review of the literature.

[Endoscopic treatment of a voluminous benign symptomatic cyst of the pineal region responsible for an obstructive hydrocephalus]. / Traitement endoscopique d'un volumineux kyste bénin symptomatique de la région pinéale responsable d'une hydrocéphalie obstructive.

Asymptomatic non neoplastic cysts of the pineal region are common incidental findings in adults. On the contrary, voluminous and symptomatic cysts of the pineal region are rare and their management are not well defined. We present the case of a 32-year-old woman suffering who suffered from mild intracranial hypertension, gait disturbance and vertigo for one year. The neuroradiological workup showed a voluminous cyst of the pineal region responsible for an obstructive hydrocephalus. An endoscopic etiological treatment was decided. The operation consisted in a marsupialization of the cyst in the third ventricle with a stereotactic guidance system. A frozen section of the cyst wall failed to show tumoral cells. Immediate postoperative course was uneventful. Intracranial hypertension symptoms resolved in 24 hours. Clinical examination and neuropsychological testing were normal at two years postoperatively. The two years follow-up cerebral MRI demonstrated a remnant cystic cavity without mass effect and the patency of the aqueduct of Sylvius. Endoscopic treatment of symptomatic pineal cysts constitutes an interesting therapeutic alternative in the management of this pathology.

Depressed skull fracture overlying the superior sagittal sinus causing benign intracranial hypertension. Description of two cases and review of the literature.

The purpose of this report is to describe successful surgical treatment of benign intracranial hypertension (BIH) in two patients presenting with depressed skull fractures over the superior sagittal sinus (SSS). The first case involved a 22-year-old patient who presented with depressed skull fracture overlying the posterior third of the SSS. Symptoms of BIH developed within 48 h. The second case involved a 33-year-old patient who presented with depressed skull fracture overlying the junction between the middle and posterior thirds of the SSS. Symptoms of BIH developed 1 month after. Although this patient presented with bilateral papilloedema, the less straightforward nature of his BIH symptoms prompted us to undertake further neuroradiological assessment by angiography with retrograde venous catheterization. A high-pressure gradient was found between venous flow upstream and downstream from the compressed zone. Both patients underwent surgical decompression in the lateral decubital position. Continuous monitoring of intracranial pressure was begun upon induction of general anaesthesia. High preoperative pressure declined immediately after elevation of the depressed zone. Bleeding was not a problem at any time during the procedure. Follow-up MRI and angio-MRI demonstrated total restoration of SSS patency. Benign intracranial hypertension is an uncommon complication of depressed skull fracture. Retrograde venous catheterization with pressure measurement can be a useful diagnostic adjunct. Surgical treatment is indicated in symptomatic patients. Based on the two cases reported, we now propose MRI venography in all patients presenting with symptoms of BIH and arteriography with retrograde venous catheterization when venous sinus stenosis exists.

[Stereotactic mapping for radiosurgical treatment of vestibular schwannomas]. / Imagerie stéréotaxique de repérage dans le traitement radiochirurgical des schwannomes vestibulaires.

RATIONALE: As an exclusively image-guided surgery method, radiosurgery requires special attention in the choice of imaging modalities and acquisition parameters must be set with extreme care. METHODS: Quality control for resolution and accuracy of computed tomography (CT) scanners must be performed. Magnetic resonance imaging (MRI) distortions should be limited through magnetic field homogeneity adjustment (shimming) and acquisition parameters optimization. These inaccuracies should then be quantified through systematic combination of MRI and CT in the radiosurgery planning system. MRI pulse sequences selection criteria are defined by their ability to delineate tumor contrast enhancement and to image cranial nerves and vessels relative arrangement in the cistern and canal. Topography of the petrous structures, such as cochlea, vestibulum and facial nerve canal should be visible. Exact definition of real extension of the lesion at the end of the canal may require specific technical solutions. These technical requirements must be balanced depending on the lesion Volume staging (Koos), the treatment history (microsurgery), the clinical condition (hearing quality), the pathological context (NF2) or the age of the patient. RESULTS: T1-weighted Volumetric MRI pulse sequences (3D-T1) show a contrast enhanced signal that is useful for both the pons interface delineation in Koos III cases, and the canal ending in Ohata A and B. On the other hand, 3D-T1 introduce inaccuracies from magnetic susceptibility distortions and partial Volume effects. High resolution CISS T2-weighted Volumetric pulse sequences (3D-T2) give superior stereotaxic definition attributable to their better resolution (half a millimeter) minimizing partial Volume effects and to their lower magnetic susceptibility minimizing distortions. 3D-T2 allows direct nerve visualization. Moreover, this pulse sequence with contrast injection, show improved distinction between the pons and the nerves due to signal differences within the schwannomas. Fat saturation pulse sequences are of interest in post-microsurgery conditions. CONCLUSIONS: Radiology phase quality is critical and its complexity requires a high commitment to obtain satisfactory clinical results. Solelt the 3D-T1 MRI modality seems to us not to comply to minimum security criteria.

Normal galenic drainage of the deep cerebral venous system in two cases of vein of Galen aneurysmal malformation.

INTRODUCTION: Vein of Galen aneurysmal malformations (VGAM) are assumed to be related to the persistence of the embryonic median prosencephalic vein of Markowski, which does not involute in cases of VGAM and becomes the venous collector of the shunt, characteristic of the malformation. The arterial feeders of VGAMs are all primitive meningeal arteries present during the embryonic period of the constitution of the malformation. It has also been assumed that the internal cerebral veins were absent in patients presenting with VGAM. There is no clear evidence indicating, however, that the deep venous structures cannot develop normally. CASE REPORTS: We report on two cases of VGAM in which superselective retrograde transvenous catheterization and MRI demonstrated that normal internal cerebral veins were draining into the aneurysmal vein of Galen. CONCLUSIONS: It is conceivable that, as in our patients, this drainage pattern is only angiographically detectable via selective retrograde transvenous drainage. The possibility of such normal deep galenic venous drainage must be considered in VGAM management, as it may imply occurrence of adverse effects when the malformation is occluded on the venous side.

Efficacy and low vascular toxicity of embolization with radical versus anionic polymerization of n-butyl-2-cyanoacrylate (NBCA). An experimental study in the swine.

BACKGROUND AND PURPOSE: To compare the efficacy and vascular toxicity of embolization with radical (NBCA+metacryloxysulpholane=CS) versus conventional anionic (NBCA alone=CA) polymerization of NBCA. MATERIALS AND METHODS: Under continuous digital subtracted angiography (DSA) recordings, a 0.2 mL volume of identical glue mixtures were injected in a single-step procedure, concomitantly, in left and right (with CS and CA, respectively) renal arterial branches (RAB) and ascending pharyngeal arteries (APA) in 8 swines. Arterial histopathology and morphometry of inflammation were investigated at 2 weeks. RESULTS: Complete embolization was achieved with equivalent cast homogeneity on DSA with both NBCA mixtures in RAB and APA. Inflammatory crowns in APA and RAB were significantly lower in CS - than in CA-treated sites (p<0.001). CS plug was scarcely adhesive to the vascular wall, and pulled apart from the wall by a residual thrombotic lining; in contrast with CA casts that were strongly adhesive to walls with endothelium stripping. CONCLUSIONS: Anionic and radical polymerization of NBCA embolization was identical with regards to occlusion rate; whereas radical pathway of polymerization with cyanoacrylates lowered histotoxicity with a less sustained adhesiveness of casts against vascular walls.

[Craniopharyngioma in children: MRI study of 43 cases]. / Les crAniopharyngiomes de l'enfant.

BACKGROUND AND PURPOSE: Craniopharyngiomas are intra-cranial tumors, relatively frequent in children, expanding in the pituitary stalk axis, from the third ventricle to the sphenoid body. Plain films and CT scan generally show a calcified lesion, deforming the sella turcica. MRI improves tumor description and topographic and structural analysis of the lesion. The aim of this study is to analyze the MRI aspect of craniopharyngiomas in a pediatric population and to correlate findings with surgical data. METHODS: MR and CT studies of 43 pediatric cases of histology-proven craniopharyngiomas were reviewed retrospectively. Tumor emergence, extensions and signal on different sequences were recorded. We searched for radio-surgical correlations. RESULTS: Craniopharyngiomas can be classified into two groups: intra-sellar tumors and third ventricle floor tumors (infundibulum and tuber cinereum). Preferential routes of extension are observed in each group correlated with consistency (cystic and/or solid). Surgical data confirmed these results. CONCLUSIONS: MRI is crucial for the pre-therapeutic evaluation of craniopharyngiomas allowing not only a detailed description of the tumor but also guiding therapeutic decisions. This series demonstrated that craniopharyngiomas exhibit two different types of localization and behavior. Embryonic development of the tumor explains the topographical differences.

Abscess-like formation concomitant with pituitary adenoma in Cushing's disease: case report and pathological considerations.

Pituitary abscess is a rare condition and a histological misnomer since cultures of abscess material are often negative or non-pathogenic. We report the first case of pituitary abscess-like formation concomitant with pituitary adenoma and discuss the physiopathological mechanism. A 37-year-old woman presented classic symptoms of Cushing's disease. Endocrine studies indicated the presence of adenocorticotropin (ACTH)-producing pituitary adenoma. Preoperative magnetic resonance imaging revealed two separate tumours of the pituitary. During transsphenoidal surgery, a 14-mm adenoma was removed from the right side of the gland and a pus-filled cystic tumour was opened and drained on the left. Histological diagnosis was ACTH-producing pituitary adenoma and cyst material compatible with pituitary abscess. Association of separate adenoma and abscess of the pituitary gland has not been reported previously. We speculate that spontaneous adenoma infarction may provide a more comprehensible pathophysiological explanation than abscess formation.

Performance of long J-shaped coils in large and giant intracranial aneurysms: an in vitro study.

We evaluated the performance of long straight coils (Detach-18 J-shaped coils) in large and giant in-vitro aneurysms. The coils consisted of a distal semicircular part 7 or 15 mm in diameter and a proximal 70 cm straight part having three types of stiffness: soft, standard, and stiff. We first investigated the ease of passage through a microcatheter in a realistic cerebral vessel model. Second, we made silicone models simulating lateral-type aneurysms of various spherical dome diameters (12, 15, 20 and 30 mm) and neck sizes (3-10 mm; dome-to-neck ratio approximately 3:1) and connected them to a pulsating circulatory pump. We evaluated the anchoring and folding patterns of the coils, stability of the microcatheter and coils in the aneurysm, and smoothness of delivery and retrieval of coils. Third, we compared the conformability of a coil in a large, irregular aneurysm with that of a spiral coil. The long J-shaped coils were easily advanced and retrieved through a microcatheter in a tortuous vessel model. In 12 mm spherical aneurysms, each coil made a complex framework, and knot formation or damage to the coil during withdrawal was often observed. In 15 mm aneurysms, the coils were all easily delivered and retrieved; standard-stiffness coils adapted best to this size. In 20 mm aneurysms, frameworks were less complex but still good with a standard or stiff coil, but those with soft coil were unstable and changed significantly within 3 min of detachment due to gravity and pulsatile flow. In 30 mm aneurysms, soft coils filled only the lower part during introduction, whereas a stiff coil still made a favourable framework. Conformability of a long J-shaped coil was superior to that of a spiral coil in a large, irregular aneurysm. Long J-shaped coils conform well to various configurations of large and giant aneurysms and can shorten procedures since a larger implant volume can be delivered with a single coil. Their principle of action may promote more favourable occlusion of irregular and large aneurysms by improved conformability and stability.

Resection of a giant intracranial dural arteriovenous fistula with the use of low-flow deep hypothermic cardiopulmonary bypass after partial embolization: technical case report.

OBJECTIVE AND IMPORTANCE: To describe the surgical resection of a giant intracerebral arteriovenous fistula with involvement of dura mater and surrounding bone. Intraoperative bleeding was controlled by hypothermic circulatory arrest. CLINICAL PRESENTATION: This 46-year-old woman complained of persistent headache for 1 year; her diagnostic workup revealed the presence of an arteriovenous fistula in the dura mater of the left temporal region fed by the meningeal artery of the external and internal carotid arteries, with normal run-off into Labbé's and Trolard's veins. Magnetic resonance imaging depicted a Chiari I malformation that was most likely a result of insufficient cerebral venous drainage. INTERVENTION: In preparation for surgery, staged embolization of feeders from the left meningeal artery and the left occipital artery was performed under controlled hypotension. This procedure failed to achieve a significant reduction in flow because of the immediate recruitment of internal branches of the internal carotid artery and dural branches of the right external carotid artery. Surgical treatment was undertaken without further embolization. Because of involvement of surrounding bone and the high risk of uncontrollable bleeding, the procedure was carried out with the patient under deep hypothermic cardiopulmonary bypass. Forty-five minutes of low flow (1.5 L/min) at 18 degrees C allowed total resection of the involved dura mater and surrounding bone. Postoperative recovery was marked by left brain edema that disappeared within 10 days. Findings on follow-up angiography were normal, and the patient was discharged with no neurological deficit. CONCLUSION: Low-flow deep hypothermic cardiopulmonary bypass can be used to control intraoperative bleeding for surgical excision of a giant intracerebral dural arteriovenous fistula.