Management of two cavernous sinus dural arteriovenous fistulae by direct microsurgical approach and catheterization of the superior ophthalmic vein.

BACKGROUND: In case of cavernous sinus dural arteriovenous fistula, transvenous embolization of the cavernous sinus via the inferior petrosal sinus is generally sufficient. However, when inferior petrosal sinus access is challenging, various alternative approaches have been reported, with corresponding difficulties and risks. CASE REPORTS: We report the management of two cases of life-threatening cavernous sinus dural arteriovenous fistula revealed by a typical cavernous sinus syndrome. Conventional approaches were unsuccessful, and a direct microsurgical approach was performed, with catheterization of the superior ophthalmic vein. This combined approach safely accessed the cavernous sinus, and obtained complete occlusion of the fistulae by Onyx® embolization. CONCLUSIONS: This procedure could be an interesting alternative option in the treatment of cavernous sinus dural arteriovenous fistula when conventional approaches are not possible.

Rupture limit evaluation of human cerebral aneurysms wall: Experimental study.

BACKGROUND AND PURPOSE: Rupture risk of intracranial aneurysms is a major issue for public healthcare. A way to obtain an individual rupture risk assessment is a main objective of many research teams in the world. For many years, we have investigated the relationship between the mechanical properties of aneurysm wall tissues and the rupture risk. In this work, we try to go further and investigate rupture limit values. METHODS: Following surgical clipping, a specific conservation protocol was applied to aneurysmal tissues in order to preserve their mechanical properties. Thirty-nine intracranial aneurysms (27 females, 12 males) were tested using a uniaxial tensile test machine under physiological conditions, temperature, and saline isotonic solution. These represented 24 unruptured and 15 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a Yeoh hyperelastic model with 2 parameters. Moreover, uniaxial tensile tests were conducted until rupture of samples to obtain values of stress and strain rupture limit. RESULTS: The significant parameter a C2 of the hyperelastic Yeoh model, allowed us to classify samples' rigidity following the terminology we adopted in previous papers (Costalat et al., 2011; Sanchez et al., 2013): Soft, Stiff and Intermediate. Moreover, strain/stress rupture limit values were gathered and analyzed thanks to the tissue rigidity, the status of the aneurysm (initially ruptured or unruptured) and the gender of the patient. CONCLUSION: Strain rupture limit was found quite stable around 20% and seems not to be correlated with the status of the aneurysm (initially ruptured or unruptured), neither with the gender of the patient. However, stretch and stress rupture limit seems not to be independent on the rigidity. The study confirms that ruptured aneurysms mainly present a soft tissue and unruptured aneurysms present a stiff material.

Delayed hemorrhagic complication after complete embolization of a brain arteriovenous malformation.

Endovascular embolization is an essential therapeutic approach in the multidisciplinary management of cerebral arteriovenous malformations (AVM). However, it rarely occludes the AVM in its entirety. It is often combined with surgery or stereotactic radiosurgery. The aim of embolization is to reduce the size of the nidus and the intra-nidal flow in order to facilitate the microsurgical or the radiosurgical procedure. We report the case of a 61-year-old patient with a right frontal hemorrhagic AVM treated with complete embolization in a single session. Initially, a surgical procedure for excision of the AVM was scheduled 24hours post-embolization. This surgery was canceled due to a good angiographic result of the embolization. Eight days post-embolization, there was a massive re-bleed of the AVM which justified emergency surgical management. This case illustrates a delayed post-embolization hemorrhagic complication of an occluded AVM and prompts a review of the therapeutic strategy of the cerebral AVM to select the most effective and least morbid procedure or combination of procedures.

Does hip joint positioning affect maximal voluntary contraction in the gluteus maximus, gluteus medius, tensor fasciae latae and sartorius muscles?

BACKGROUND: Minimally invasive total hip arthroplasty (THA) is presumed to provide functional and clinical benefits, whereas in fact the literature reveals that gait and posturographic parameters following THA do not recover values found in the general population. There is a significant disturbance of postural sway in THA patients, regardless of the surgical approach, although with some differences between approaches compared to controls: the anterior and anterolateral minimally invasive approaches seem to be more disruptive of postural parameters than the posterior approach. Electromyographic (EMG) study of the hip muscles involved in surgery [gluteus maximus (GMax), gluteus medius (GMed), tensor fasciae latae (TFL), and sartorius (S)] could shed light, the relevant literature involves discordant methodologies. We developed a methodology to assess EMG activity during maximal voluntary contraction (MVC) of the GMax, GMed, TFL and sartorius muscles as a reference for normalization. A prospective study aimed to assess whether hip joint positioning and the learning curve on an MVC test affect the EMG signal during a maximal voluntary contraction. HYPOTHESIS: Hip positioning and the learning curve on an MVC test affect EMG signal during MVC of GMax, GMed, TFL and S. METHODS: Thirty young asymptomatic subjects participated in the study. Each performed 8 hip muscle MVCs in various joint positions recorded with surface EMG sensors. Each MVC was performed 3 times in 1 week, with the same schedule every day, controlling for activity levels in the preceding 24h. EMG activity during MVC was expressed as a ratio of EMG activity during unipedal stance. Non-parametric tests were applied. RESULTS: Statistical analysis showed no difference according to hip position for abductors or flexors in assessing EMG signal during MVC over the 3 sessions. Hip abductors showed no difference between abduction in lateral decubitus with hip straight versus hip flexed: GMax (19.8±13.7 vs. 14.5±7.8, P=0.78), GMed (13.4±9.0 vs. 9.9±6.6, P=0.21) and TFL (69.5±61.7 vs. 65.9±51.3, P=0.50). Flexors showed no difference between hip flexion/abduction/lateral rotation performed in supine or sitting position: TFL (70.6±45.9 vs. 61.6±45.8, P=0.22) and S (101.1±67.9 vs. 72.6±44.6, P=0.21). The most effective tests to assess EMG signal during MVC were for the hip abductors: hip abduction performed in lateral decubitus (36.7% for GMax, 76.7% for GMed), and for hip flexors: hip flexion/abduction/lateral rotation performed in supine decubitus (50% for TFL, 76.7% for S). DISCUSSION: The study hypothesis was not confirmed, since hip joint positioning and the learning curve on an MVC test did not affect EMG signal during MVC of GMax, GMed, TFL and S muscles. Therefore, a single session and one specific test is enough to assess MVC in hip abductors (abduction in lateral decubitus) and flexors (hip flexion/abduction/lateral rotation in supine position). This method could be applied to assess muscle function after THA, and particularly to compare different approaches. LEVEL OF EVIDENCE: III, case-matched study.

Short-term comparison of postural effects of three minimally invasive hip approaches in primary total hip arthroplasty: Direct anterior, posterolateral and Röttinger.

INTRODUCTION: There is renewed interest in total hip arthroplasty (THA) with the development of minimally invasive approaches. The anterior and Röttinger approaches are attractive for their anatomical and minimally invasive character, but with no comparative studies in the literature definitely suggesting superiority in terms of quality of functional recovery. We therefore performed a case-control study, assessing: 1) whether the postural parameters of patients operated on with the anterior, Röttinger and posterior minimally invasive approaches were similar to those of asymptomatic subjects, and 2) whether there were any differences in postural parameters between the three approaches at short-term follow-up. HYPOTHESIS: We hypothesized that the anterior and Röttinger approaches are less disruptive of postural parameters than the posterior approach. METHODS: Seventy subjects (44 primary THA patients and 26 asymptomatic control subjects) were enrolled. Operated subjects were divided into 3 experimental groups corresponding to the 3 minimally invasive approaches: posterior (n=14), anterior (n=15) and Röttinger (n=15). Two single-leg stance tests (left followed by right leg stance; 10s per test) were carried out on a stabilometric platform, within 2months after surgery for all THA patients, and for controls. Six significant parameters were selected for statistical analysis: test performance, mediolateral and anteroposterior displacements of the center of pressure (CP), path length, average CP displacement speed, and the ellipse containing 95% of CP projections. Non-parametric statistical tests were used to compare groups. RESULTS: There was no difference between the 3 study groups and the control group according to age, gender, BMI, or side (or between study groups regarding WOMAC score). No significant differences between approaches were found for success on postural tests (P=0.14). Subjects operated on with the anterior or Röttinger approach showed significant differences from asymptomatic subjects for 2 postural parameters: path length (Röttinger P=0.04, anterior P=0.03) and average CP displacement speed (Röttinger P=0.04, anterior P=0.03). Subjects operated on through the posterior approach showed no significant differences from asymptomatic subjects. DISCUSSION: The study hypothesis, that the anterior and Röttinger approaches for hip arthroplasty are less disruptive of postural parameters than the posterior approach, was not confirmed. The anterior and Röttinger approach groups showed higher average CP displacement speed and path length, suggesting that they use up more energy resources to maintain static balance. The posterior approach had the least impact on postural parameters in the first 2 postoperative months. LEVEL OF EVIDENCE: III, case-control study.

Ruptured posterior ethmoidal artery aneurysm and Moyamoya disease in an adult patient. Case report.

The association between Moyamoya disease and intracranial aneurysms is well described. In our case, we describe a unique aneurismal location and its management. We report the case of a 74-year-old woman affected by a Moyamoya disease who displayed a frontal lobe hematoma. The origin of the bleeding came from the rupture of a posterior ethmoidal artery aneurysm that was treated surgically with favourable outcome. This case of a ruptured posterior ethmoidal artery aneurysm in a Moyamoya patient illustrates the polymorphism of the vascular complications encountered in this disease. It stresses the need to obtain information from an angiographic investigation in order to select the best therapeutic option and to reduce procedural complications.

Patient selection for stroke endovascular therapy--DWI-ASPECTS thresholds should vary among age groups: insights from the RECOST study.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the benefits of endovascular intervention in large-vessel occlusion strokes, depending on age class. MATERIALS AND METHODS: A clinical management protocol including intravenous treatment and mechanical thrombectomy was instigated in our center in 2009 (Prognostic Factors Related to Clinical Outcome Following Thrombectomy in Ischemic Stroke [RECOST] study). All patients with acute ischemic stroke with an anterior circulation major-vessel occlusion who presented within 6 hours were evaluated with an initial MR imaging examination and were analyzed according to age subgroups (younger than 50 years, 50-59 years, 60-69 years, 70-79 years; 80 years or older). The mRS score at 3 months was the study end point. RESULTS: One hundred sixty-five patients were included in the analysis. The mean age was 67.4 years (range, 29-90 years). The mean baseline NIHSS score was 17.24 (range, 3-27). The mean DWI-derived ASPECTS was 6.4. Recanalization of TICI 2b/3 was achieved in 80%. At 3 months, 41.72% of patients had a good outcome, with a gradation of prognosis depending on the age subgroup and a clear cutoff at 70 years. Only 19% of patients older than 80 years had a good outcome at 3 months (mean ASPECTS = 7.4) with 28% for 70-79 years (mean ASPECTS = 6.8), but 58% for 60-69 years (mean ASPECTS = 6), 52% for 50-59 years (mean ASPECTS = 5.91), and 72% for younger than 50 years (mean ASPECTS = 6.31). In contrast, the mortality rate was 35% for 80 years and older, and 26% for 70-79 versus 5%-9% for younger than 70 years. CONCLUSIONS: The elderly may benefit from thrombectomy when their ischemic core volume is low in comparison with younger patients who still benefit from acute recanalization despite larger infarcts. Stroke volume thresholds should, therefore, be related and adjusted to the patient's age group.

Extra-aneurysmal flow modification following pipeline embolization device implantation: focus on regional branches, perforators, and the parent vessel.

BACKGROUND AND PURPOSE: Flow-diverter technology has proved to be a safe and effective treatment for intracranial aneurysm based on the concept of flow diversion allowing parent artery and collateral preservation and aneurysm healing. We investigated the patency of covered side branches and flow modification within the parent artery following placement of the Pipeline Embolization Device in the treatment of intracranial aneurysms. MATERIALS AND METHODS: Sixty-six aneurysms in 59 patients were treated with 96 Pipeline Embolization Devices. We retrospectively reviewed imaging and clinical results during the postoperative period at 6 and 12 months to assess flow modification through the parent artery and side branches. Reperfusion syndrome was assessed by MR imaging and clinical evaluation. RESULTS: Slow flow was observed in 13 of 68 (19.1%) side branches covered by the Pipeline Embolization Device. It was reported in all cases of anterior cerebral artery coverage, in 3/5 cases of M2-MCA coverage, and in 5/34 (14.7%) cases of ophthalmic artery coverage. One territorial infarction was observed in a case of M2-MCA coverage, without arterial occlusion. One case of deep Sylvian infarct was reported in a case of coverage of MCA perforators. Two ophthalmic arteries (5.9%) were occluded, and 11 side branches (16.2%) were narrowed at 12 months' follow-up; patients remained asymptomatic. Parent vessel flow modification was responsible for 2 cases (3.4%) of reperfusion syndrome. Overall permanent morbidity and mortality rates were 5.2% and 6.9%, respectively. We did not report any permanent deficit or death in case of slow flow observed within side branches. CONCLUSIONS: After Pipeline Embolization Device placement, reperfusion syndrome was observed in 3.4%, and territorial infarction, in 3.4%. Delayed occlusion of ophthalmic arteries and delayed narrowing of arteries covered by the Pipeline Embolization Device were observed in 5.9% and 16.2%, respectively. No permanent morbidity or death was related to side branch coverage at midterm follow-up.

Intracranial aneurysmal pulsatility as a new individual criterion for rupture risk evaluation: biomechanical and numeric approach (IRRAs Project).

BACKGROUND AND PURPOSE: The present study follows an experimental work based on the characterization of the biomechanical behavior of the aneurysmal wall and a numerical study where a significant difference in term of volume variation between ruptured and unruptured aneurysm was observed in a specific case. Our study was designed to highlight by means of numeric simulations the correlation between aneurysm sac pulsatility and the risk of rupture through the mechanical properties of the wall. MATERIALS AND METHODS: In accordance with previous work suggesting a correlation between the risk of rupture and the material properties of cerebral aneurysms, 12 fluid-structure interaction computations were performed on 12 "patient-specific" cases, corresponding to typical shapes and locations of cerebral aneurysms. The variations of the aneurysmal volume during the cardiac cycle (ΔV) are compared by using wall material characteristics of either degraded or nondegraded tissues. RESULTS: Aneurysms were located on 6 different arteries: middle cerebral artery (4), anterior cerebral artery (3), internal carotid artery (1), vertebral artery (1), ophthalmic artery (1), and basilar artery (1). Aneurysms presented different shapes (uniform or multilobulated) and diastolic volumes (from 18 to 392 mm3). The pulsatility (ΔV/V) was significantly larger for a soft aneurysmal material (average of 26%) than for a stiff material (average of 4%). The difference between ΔV, for each condition, was statistically significant: P=.005. CONCLUSIONS: The difference in aneurysmal pulsatility as highlighted in this work might be a relevant patient-specific predictor of aneurysm risk of rupture.

Submandibular puncture of the facial vein: an original route for endovascular therapy of cavernous sinus dural fistulas.

INTRODUCTION: Carotid cavernous sinus fistulas are a potentially severe pathology. Their basic standard treatment is an occlusion of the CCF performed by retrograde venous catheterization via the inferior petrous sinus. When the inferior petrous sinuses are occluded, other alternative venous routes are possible with various subsequent difficulties and risks. We report an original and safe method for endovascular treatment using submandibular puncture of the facial vein. CLINICAL CASES: We report 4 cases of patients with severe unilateral carotid cavernous sinus fistula associated with the occlusion of both inferior petrous sinuses. A submandibular surgical puncture of the ipsilateral inferior facial vein permitted the catheterization of the fistula. Complete occlusion of carotid cavernous sinus fistula was obtained by using a combination of microcoils and Onyx™. DISCUSSION: When inferior petrous sinuses are occluded, endovascular treatment of carotid cavernous sinus fistulas is more difficult. After reviewing the other treatment options reported in the literature and their respective advantages and adverse effects, we describe an original technique based on the surgical puncture of the ipsilateral facial vein. The occlusion of the fistula is then obtained by using a combination of microcoils and Onyx™. CONCLUSION: When the inferior petrous sinuses are occluded, an endovascular treatment for a carotid cavernous sinus fistula can be performed using an original and secure method. This method relies on a simple surgical puncture of the facial vein in the submandibular region, which then permits a retrograde catheterization of the carotid cavernous sinus fistula with no significant risk.

[Carotid-cavernous sinus fistula: an unusual cause of exophthalmia. Report of three cases]. / Une cause inhabituelle d'exophtalmie uni- ou bilatérale : les fistules artérioveineuses carotidocaverneuses. Trois observations.

INTRODUCTION: Exophthalmia can be associated with several disorders. Although unusual, a carotid-cavernous fistula should be ruled out systematically as it may be associated with severe complications. CASE REPORTS: We report three cases associated with both types of carotid-cavernous fistula that highlight the clinical presentation and diagnostic process. CONCLUSION: A carotid-cavernous fistula should be systematically ruled out in patients with a uni- or bilateral exophthalmia. Careful examination with auscultation of the ocular globe contributes greatly to the diagnosis that may be confirmed by MRI or arteriography.

Flow-diverter silk stent for the treatment of intracranial aneurysms: 1-year follow-up in a multicenter study.

BACKGROUND AND PURPOSE: FD stent placement is a promising therapy for challenging intracranial aneurysms. Long-term evaluations about angiographic and morphologic results are still missing. This is the aim of this multicenter series. MATERIALS AND METHODS: We report our experience and 1-year FU in a retrospective chart review of 65 consecutive subjects with 77 unruptured or recanalized aneurysms that were treated with Silk FD stents at 6 centers in France. Both angiographic and clinical results were recorded before treatment and at 6 and 12 months after treatment. At the 12-month FU, relationships between angiographic aneurysm occlusion and shrinkage of the thrombosed aneurysm sac were evaluated. RESULTS: Stent deployment was achieved in 64 cases (98.5%) and failed in 1 case (1.5%). Seven misdeployments of the Silk stent caused the occlusion of 6 parent arteries. Overall acute/subacute procedural morbidity was 7.7%, and mortality was zero. Delayed complications were observed in 10.9% of subjects. At the 6-month FU, permanent morbidity was 7.8% and mortality was 3%. Complete occlusion occurred within 6 months in 68% of aneurysms and within 12 months after treatment in 84.5% of aneurysms. At the 12-month FU, in angiographically complete occluded aneurysms, MR imaging/CT analysis showed the complete disappearance of the thrombosed aneurysm in 30% of cases and partial shrinkage in 52%; furthermore, thrombosed aneurysms were stable in 11% of cases and enlarged in 7%. CONCLUSIONS: The Silk stent is an effective tool for the treatment of challenging aneurysms because it allows complete occlusion in most cases 1 year after treatment. Permanent morbidity was 7.8%, and mortality was 3%.

Biomechanical wall properties of human intracranial aneurysms resected following surgical clipping (IRRAs Project).

BACKGROUND AND PURPOSE: Individual rupture risk assessment of intracranial aneurysms is a major issue in the clinical management of asymptomatic aneurysms. Aneurysm rupture occurs when wall tension exceeds the strength limit of the wall tissue. At present, aneurysmal wall mechanics are poorly understood and thus, risk assessment involving mechanical properties is inexistent. Aneurysm computational hemodynamics studies make the assumption of rigid walls, an arguable simplification. We therefore aim to assess mechanical properties of ruptured and unruptured intracranial aneurysms in order to provide the foundation for future patient-specific aneurysmal risk assessment. This work also challenges some of the currently held hypotheses in computational flow hemodynamics research. METHODS: A specific conservation protocol was applied to aneurysmal tissues following clipping and resection in order to preserve their mechanical properties. Sixteen intracranial aneurysms (11 female, 5 male) underwent mechanical uniaxial stress tests under physiological conditions, temperature, and saline isotonic solution. These represented 11 unruptured and 5 ruptured aneurysms. Stress/strain curves were then obtained for each sample, and a fitting algorithm was applied following a 3-parameter (C(10), C(01), C(11)) Mooney-Rivlin hyperelastic model. Each aneurysm was classified according to its biomechanical properties and (un)rupture status. RESULTS: Tissue testing demonstrated three main tissue classes: Soft, Rigid, and Intermediate. All unruptured aneurysms presented a more Rigid tissue than ruptured or pre-ruptured aneurysms within each gender subgroup. Wall thickness was not correlated to aneurysmal status (ruptured/unruptured). An Intermediate subgroup of unruptured aneurysms with softer tissue characteristic was identified and correlated with multiple documented risk factors of rupture. CONCLUSION: There is a significant modification in biomechanical properties between ruptured aneurysm, presenting a soft tissue and unruptured aneurysms, presenting a rigid material. This finding strongly supports the idea that a biomechanical risk factor based assessment should be utilized in the to improve the therapeutic decision making.

Mechanical thrombectomy in acute ischemic stroke: catch device.

BACKGROUND AND PURPOSE: Mechanical thrombectomy presents today a promising alternative to traditional stroke therapies. Our aim with this study was to evaluate the safety and efficacy of the Catch mechanical thrombectomy device in the treatment of acute stroke and report the angiographic results and clinical outcomes. MATERIALS AND METHODS: We performed an analysis of 40 consecutive patients with ischemic stroke treated with the Catch device at our academic center. Forty patients were treated with the device: 25 with anterior circulation stroke and 15 with posterior circulation stroke. Thirty seven (92.5%) patients received an additional treatment to aid revascularization, including 36 patients treated with rtPA (mean dose of 35 mg). RESULTS: The mean age was 63.5 years (range, 31-82 years; 55% men). The median NIHSS score at presentation was 18 (range, 3-38). The mean symptom-to-procedure start time was 440 minutes (range, 150-2637 minutes). Recanalization (TIMI 2-3) was achieved in 26/40 (65%). Symptomatic hemorrhage occurred in 18%. Procedural complications occurred in 6 patients without clinical consequences: 4 clot fragmentations and 2 vasospasms. Data were missing for 4 patients at 90 days. Ninety-day mortality was 41%; good 90-day functional outcome (mRS, ≤ 2) was achieved by 39% (14/36). Good neurologic outcomes at 90 days were more frequent (56.5% versus 7.7%), and mortality rates were lower (30% versus 61.5%) with successful compared with unsuccessful recanalization. CONCLUSIONS: In our retrospective case series, the Catch device appears effective in achieving recanalization and improving 90-day outcome in patients with acute ischemic stroke.

Stent-assisted coiling of complex middle cerebral artery aneurysms: initial and midterm results.

BACKGROUND AND PURPOSE: Clinical outcome and initial and midterm angiographic results of EVT of complex MCA aneurysms by using the stent-assisted coiling technique were retrospectively evaluated in our center where EVT of intracranial aneurysms is the first treatment option. MATERIALS AND METHODS: From November 2003 to October 2009, 49 patients (27 men, 22 women; mean age, 52 ± 12 years) harboring 52 complex unruptured MCA aneurysms (11 ruptured previously and coiled but recanalized and 41 unruptured) were treated by EVT by using self-expandable intracranial stents. Procedural complications, clinical outcome, and initial and midterm angiographic results were evaluated. Initial treatment status and aneurysm sac size were tested as potential risk factors for recurrence. RESULTS: After successful stent deployment, coiling was performed in 50 aneurysms (96.2%) in 47 patients; however, 2 failures (3.8%) occurred in 2 patients. Ten intrastent clot formations (20%) observed on final control angiography induced 2 permanent moderate disabilities (GOS score = 2). Mortality and permanent neurologic morbidity were 0% and 4.3%, respectively. At a mean period of 14 ± 9 months, among 48 aneurysms in 45 patients eligible for follow-up, 34 complete (71%) and 14 partial treatments (29%) were observed, 7 recurrences (14.6%) occurred, and 5 patients (10.4%) needed retreatment. No aneurysm bleeding or symptomatic intrastent stenosis was observed. Aneurysm sac size ≥7 mm and incomplete initial treatment were associated with more recurrences without a statistically significant difference. CONCLUSIONS: For complex unruptured MCA aneurysms, EVT by using a self-expandable intracranial stent was feasible, safe, and durable and could be considered as the first-option treatment.

[Paraspinal arteriovenous malformations with perimedullary venous drainage]. / Malformations artérioveineuses paraspinales à drainage veineux épidural.

Symptoms of chronic myelopathy in cases of paraspinal arteriovenous malformations are most often related to perimedullary venous drainage. Here, we report on three cases of such malformations that have unique epidural venous drainage. These thoracolumbar lesions manifested as isolated back pain (in two cases) and S1 lumboradicular pain (in one case). MRI presented evidence to suggest a diagnosis of these rare conditions, based on signs of vertebral erosion, signal loss (flow void) on T1- and T2-weighted imaging, and partial enhancement after gadolinium injection, with no signs of congestive myelopathy. Spinal angiography confirmed the presence of a paraspinal fistula and, at the same time, allowed treatment by intra-arterial onyx injection.