Dural arteriovenous fistula in association with heterotopic brain nodule in the transverse sinus

We describe a 56-year-old woman with a dural arteriovenous fistula involving the transverse sinus in association with a nodule of heterotopic brain tissue in the sinus. This finding is discussed in light of a recent radiologic study of nodules in the transverse sinus.     

A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.     

Postoperative hyperperfusion in dural arteriovenous fistula associated with venous ischemia: case report

BACKGROUND: It is well known that carotid endarterectomy and extracranial-intracranial arterial bypass sometimes cause postoperative hyperperfusion, and vasoparalysis attributable to long-standing ischemia has been suggested as the cause. It is also well known that dural arteriovenous fistula (AVF) sometimes causes cerebral ischemia attributable to venous hypertension. However, there are few reports regarding the postoperative changes of regional cerebral blood flow (rCBF). METHODS: We report a case of dural AVF of the left transverse/sigmoid sinuses, occurring in a 64-year-old man. Intraoperative transvenous embolization combined with transarterial embolization was performed, and the rCBF was measured pre- and postoperatively using 99mTc-hexamethyl-propylene amine oxime and single-photon emission computed tomography (SPECT). RESULTS: Preoperative SPECT disclosed a marked rCBF reduction in the left temporal, parietal, and occipital lobes. Complete obliteration of the AVF was attained after the intraoperative transvenous embolization, without any neurological deterioration. However, postoperative SPECT demonstrated temporary hyperperfusion in these regions. CONCLUSIONS: Sudden resolution of venous ischemia can lead to postoperative hyperperfusion, and pre- and post-treatment rCBF studies are important to prevent complications related to hyperperfusion.     

Hypothalamic hamartoma associated with dural arteriovenous fistula of the transverse-sigmoid sinus--case report

A 32-year-old female presented with a hypothalamic hamartoma associated with a dural arteriovenous fistula (DAVF) of the left transverse-sigmoid sinus. She complained of pulsatile tinnitus in the left retroauricular region and infertility. Endocrinological examination revealed that the luteinizing hormone reaction to luteinizing hormone-releasing hormone was exceedingly high. Magnetic resonance imaging demonstrated a distinct mass occupying the suprasellar cistern and protruding into the third ventricle. Left carotid angiography demonstrated a DAVF of the left transverse-sigmoid sinus, which was treated by embolization. Histological examination of a biopsy specimen of the tumor revealed a hamartoma. She was free from pulsatile tinnitus after treatment for the DAVF.     

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE: In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs. METHODS: Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated. RESULTS: The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels." CONCLUSIONS: The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.     

Paralysis of the hypoglossal nerve in the presentation of dural arteriovenous fistula of the posterior fossa

BACKGROUND: Left-ventricular assist device implantation (LVAD) is still associated with thromboembolism as the optimal anticoagulation is still unclear. We report on the effects of adding platelet inhibitors to our anticoagulation regimen in our Novacor LVAD program. METHODS: Oral platelet aggregation inhibitors (aspirin 330 mg + dipyridamole 75 mg, three times per day) were added to the heparin/phenprocoumon treatment in 9 patients starting on postoperative day 3 to 7 (group A). Of the previous 41 patients, the last 20 patients served as a control group (group B), to reduce any learning curve effect. RESULTS: The mean interval of mechanical support between the two groups was comparable (group A vs B: 148 +/- 127 vs 104 +/- 61 days, n.s.). Accordingly, the cumulative support was much lower in group A (1051 days) as compared to group B (2091 days). In group B, 10 patients (50%) developed clinically evident thromboembolism. The number of events ranged from 1 to 10 (mean 1.4 +/- 2.3), with a total of 32. With addition of platelet inhibitors, the incidence of cerebral embolism dramatically dropped, as only one patient presented with transient ischemic attacks in group A (p < 0.05). Thoracic bleeding as defined by excessive drainage losses requiring redo thoracotomy did not increase (group A vs B: 22% vs 20%, n.s.). CONCLUSION: Addition of platelet inhibitors to heparin/phenprocoumon effectively prevents thromboembolism. However, platelet inhibitors should be postponed until sufficient hemostasis is achieved, since too early administration is associated with an increased risk of bleeding.     

Risks and therapy options in dural arteriovenous fistulas between branches of the external carotid artery and the cavernous sinus. A case report and review of the literature

INTRODUCTION: Dural arteriovenous fistula of the Arteria carotis externa and the sinus cavernosus are rare vascular malformations. In the literature the prognosis and necessity of treatment is described very variable. PATIENTS AND METHODS: A 90 year old female presents in our outpatient clinic with acute exophthalmus, dilated episcleral veins, cerebral bruits and beginning orbital apex syndrome. After normal computerized axial tomography (CAT) without and with contrast medium, we were able to diagnose a dural AV-fistula by angiography. Shortly after dismission the patient had a spontaneous subarachnoidal haemorrhage with severe neurological symptoms. CONCLUSIONS: The suspect of an intracranial AV-malformation implies a detailed diagnostic search with precise localisation of the process. In any patient with intracerebral and intracranial fistula there has to be an individual check of possible and necessary treatment. It is impossible to classify dural AV-fistula as a benign disease with harmless clinical course.     

Acquired dural arteriovenous malformations of the lumbar spine: case report

OBJECTIVE AND IMPORTANCE: Although dural arteriovenous malformations (AVMs) are considered to be acquired, no conclusive evidence has been obtained. The first case of dural AVMs of the lumbar spine that showed evidence supporting their being acquired lesions is described. CLINICAL PRESENTATION: A 27-year-old man was admitted to our hospital in November 1994, presenting with increasing pain and numbness in the left buttock to the left lower limb. Myelography and arteriography showed dural AVMs of the lumbar spine. However, the myelogram obtained before surgery for lumbar disc herniation in 1987 provided no findings suggestive of intradural vascular anomalies. INTERVENTION: Embolization procedures via the left iliolumbar arteries were performed. However, there was no improvement of the symptoms, and the patient underwent surgical treatment. CONCLUSION: The present report documents a case of dural AVMs of the lumbar spine that showed evidence supporting their being acquired lesions.     

A case of pulmonary arteriovenous fistula beneath the surface of the lung]

Mediastinal Hodgkin's disease has rarely been reported in the literature in Japan; however, it is not uncommon in Europe and North America. A 32-year-old woman with isolated mediastinal Hodgkin's disease mimicking thymoma is herein described. A preoperative diagnosis of thymoma led to a combined resection of the mediastinal tumor together with the entire thymus, left innominate vein, and left phrenic nerve. The resected tumor was histologically diagnosed to be Hodgkin's disease of the nodular sclerosis type. Adjuvant 40 Gy irradiation of the mediastinum and neck was added postoperatively. The patient is doing well at present with no signs of recurrence 8 months after the operation.     

A case of spontaneous arteriovenous fistula presenting as the partial oculomotor nerve palsy

We report a case of partial oculomotor nerve palsy due to spontaneous arteriovenous fistula. A 62-year-old man noticed double vision on downward gaze and periorbital pain. Clinical examination revealed inability to move the left eye downwards and to the right, and also anisocoria. No conjunctival injection or proptosis was noted. Findings of computed tomographic scan, magnetic resonance imaging and magnetic resonance angiography of the orbits, cavernous sinus region and brainstem were all normal. Carotid angiography demonstrated arteriovenous fistula via the left ophthalmic artery, the dural branch of the left external carotid artery, and the dural branch of the right internal carotid artery. Partial oculomotor palsy in this case indicated that the left inferior branch of the oculomotor nerve was affected. Inferior branch palsy of the oculomotor nerve in spontaneous arteriovenous fistula has not been described in the literature, while it is reported in cases of trauma, tumor, or aneurysm of the cavernous sinus.     

Combining endovascular and neurosurgical treatments of high-risk dural arteriovenous fistulas in the lateral sinus and the confluence of the sinuses

OBJECT: The authors describe the use of a systemic approach to treat dural arteriovenous fistulas (DAVFs) in the lateral sinus and the confluence of sinuses in 17 patients who presented with signs and symptoms related to intracranial hemorrhage, infarction, and diffuse brain swelling. METHODS: Angiographic examination revealed three different types of DAVFs in these high-risk patients: 1) extremely high flow DAVF not associated with sinus occlusion or leptomeningeal retrograde venous drainage (LRVD); 2) localized DAVF with exclusive LRVD and without sinus occlusion; and 3) diffuse DAVF with sinus occlusion and LRVD. Because of the complex nature of these lesions, the authors adopted a staged protocol in which they combined endovascular and surgical treatments. CONCLUSIONS: The authors believe that by close collaboration between endovascular therapists and vascular neurosurgeons, high-risk DAVFs in the lateral sinus and the confluence of sinuses can be successfully managed without treatment-related morbidity and mortality.     

Radical resection of meningiomas and arteriovenous fistulas involving critical dural sinus segments: experience with intraoperative sinus pressure monitoring and elective sinus reconstruction in 10 patients

OBJECTIVE: Radical resection of meningiomas and dural arteriovenous fistulas involving functional major dural sinuses entails the risk of intracranial hypertension and venous infarction. Surgical reconstruction of dural sinuses and bridging veins increases the spectrum of dural sinus conditions that can be treated by complete resection, but indications for venous reconstructions and associated risks are still not well defined. We report our experience with sinus reconstruction based on the intraoperative assessment of collateral venous flow. METHODS: Radical resection of meningiomas (n = 5) or dural arteriovenous fistulas (n = 5) involving critical segments of dural sinuses was performed in 10 patients. All but two patients were suffering from recurrent disease after incomplete treatment. Tolerance of sinus occlusion was assessed intraoperatively by measuring stump pressure in the superior sagittal sinus during test clamping of the involved sinus segment. RESULTS: In five patients, the results of pressure monitoring suggested that occlusion of the sinus might not be tolerated. In two other patients, major bridging veins entered the diseased segment. In these patients, the resected sinus segment was reconstructed and bridging veins were reinserted as far as possible. Postoperative graft occlusion occurred in two patients. One patient who was managed without reconstruction sustained a transient postoperative neurological deficit resulting from venous congestion in the vein of Labbé. Postoperative imaging confirmed total elimination of the pathological process in all 10 patients. There was no recurrence of disease during follow-up periods of up to 8 years. CONCLUSION: The monitoring of sinus pressure, together with the possible reconstruction of the diseased sinus, allows complete surgical treatment of dural sinus abnormalities and involves acceptable risk.     

A case of successful resection of pulmonary arteriovenous fistula with a high shunt ratio

We report on a 25-year-old cyanotic man who was diagnosed as having a pulmonary arteriovenous fistula. His chief complaint had been shortness of breath since childhood. Polycythemia (Hb 21.4 g/dl) was detected during a health checkup at his company. A chest X-ray showed an abnormal mass in the left lung. Blood gas analysis showed severe hypoxia with PaO2 of 38.6 mmHg at room air. Angio-CT showed a large aneurysmal lesion at S6 of the left lung with a large feeding artery and vein. Oxygen saturation was 75.2% in the radial artery and 62.5% in the right atrium. The right-to-left shunt ratio was therefore calculated as 62%. The aneurysmal lesion was resected by segmentectomy of the left S6 following division of A6 and V6. After a successful operation, the patient no longer had shortness of breath or cyanosis and blood gas analysis showed PaO2 as 84.3 mmHg at room air. Pulmonary angiography showed no residual shunt lesion.     

MR imaging and MR angiography in the diagnosis of dural arteriovenous fistulas

Intracranial DAVFs are most commonly found in the cavernous, transverse, and sigmoid sinuses. MR imaging and MR angiography can be used to screen for these lesions and determine if there is cortical venous drainage. Conventional angiography still has a major role in screening and is mandatory prior to any therapy. Spinal DAVFs are uncommon lesions seen predominantly in older men. The diagnosis can be suspected with MR imaging if a large draining vein is seen in association with swelling and enhancement of the conus and increased signal on T2-weighted images. MR angiography shows some promise in identifying the vascular anatomy of these lesions.     

Outcome and prognostic factors in the surgical treatment of spinal dural arteriovenous fistulas. A long-term study

The small leucine-rich bone proteoglycans, biglycan and decorin, can be purified by chromatography on hydroxyapatite columns, demonstrating their potential affinities for bone apatite. To determine their effects on in vitro apatite formation and growth, a mixture of the chondroitin-sulfate (CS) bone proteoglycans, or purified fractions of the dermatan sulfate (DS) containing proteoglycans, DS-decorin and DS-biglycan obtained from skin and articular cartilage, respectively, were analyzed in a gelatin gel diffusion system in which apatite formation occurs in the absence of proteins in a 3.5 day period. Low concentrations of the bone CS-proteoglycan mixture and low DS-biglycan concentrations (5-25 microg/ml) increased apatite formation relative to proteoglycan-free controls at 3.5 days. The CS-proteoglycan mixture was less effective at 50 microg/ml than at 10 microg/ml. DS-biglycan was similarly most effective at 5-25 microg/ml. At 5 days, when apatite growth and proliferation were assessed, 10 and 50 microg/ml of both CS-bone proteoglycan and DS-biglycan increased mineral yields. DS-decorin, in contrast, had no significant effect on mineral accumulation at any of these concentrations. In seeded growth experiments, 1 and 10 microg/ml CS-proteoglycan and 10 and 50 microg/ml DS-biglycan were significant effective inhibitors of mineral accretion, whereas DS-decorin showed no tendency to inhibit seeded growth. Using molar extinction coefficients to determine concentrations, the binding of DS-biglycan and DS-decorin to apatite (specific surface 54 m2/g) was determined using a Langmuir adsorption isotherm model. DS-biglycan had a greater affinity for apatite than DS-decorin (0.285 ml/micromol versus 0.0098 ml/micromol). DS-biglycan binding was more specific with fewer binding sites (3.5 micromol/m2 compared with 18. 2 micromol/m2 for DS-decorin). Data suggest that of the small proteoglycans, biglycan may play a more significant role than decorin in the regulation of mineralization.     

A post-thymomectomy case of myasthenia gravis which developed nephrotic syndrome with membranous nephropathy during azathioprine administration

We report a 46-year-old woman who has been suffered from myasthenia gravis and underwent thymomectomy in December 1988. Her myasthenic symptoms improved by treatment with corticosteroid and azathioprine; the latter drug was administrated for more than one year. She noticed weight gain of 10 kg and edema in both legs and feet, which developed acutely in August 1994. Laboratory data showed that she suffered from nephrotic syndrome with a large amount of proteinuria (15 g/day). Renal biopsy revealed that biopsied glomeruli showed early stage of membranous nephropathy associated with acute tubular necrosis. Although therapeutic trials of steroid pulses could not eliminate proteinuria, substitution of cyclophosphamide for azathioprine brought marked improvement of the nephrotic syndrome with disappearance of the urinary protein excretion within 10 days. From reports of similar cases with myasthenia gravis in Japan and in Europe, therapeutic usage of azathioprine in patients with myasthenia gravis associated with thymoma should be cautious for appearance of nephrotic syndrome when azathioprine is continued for more than one year.     

A case of pulmonary arteriovenous fistula presenting as multiple brain abscesses after a sustained period without treatment

A 64-year-old man was admitted to our hospital with multiple brain abscesses accompanied by pulmonary arteriovenous fistula (PAVF). He had been diagnosed with PAVF eight years previously, but had refused any treatment despite a developing exertional dyspnea. Rendu-Osler-Weber disease was diagnosed as well because the patient exhibited teleangiectasis of the nasopharyngeal mucosa and persistent gastro-intestinal bleeding. Despite administration of antibiotics and corticosteroids the abscesses perforated into the lateral ventricle. The natural history of this rare disease is still incompletely understood. Thus, the time at which treatment should be commenced remains unclear. However the natural course of PAVF is unsatisfactory, and it appears that treatment by surgery and/or embolization should be considered in all cases.     

Combined pretemporal and endovascular approach to the cavernous sinus for the treatment of carotid-cavernous dural fistulae: technical case report

OBJECTIVE AND IMPORTANCE: The endovascular treatment of carotid-cavernous dural fistulae is becoming the prominent treatment modality for these lesions. The intractability of these lesions and their tendency to recur, especially after previous endovascular treatment sessions, exhausts the available routes and tends to present a difficulty in accessing the cavernous sinus. To avoid the risks associated with a direct surgical approach, an alternative, less invasive route to the cavernous sinus using a pretemporal extradural approach is combined with a direct endovascular approach. CLINICAL PRESENTATION: A 38-year-old woman presented with a history of right visual and ocular symptoms related to a Type D cavernous carotid dural fistula, which was fed by internal carotid and external carotid branches. The fistula was initially treated with embolization of the external carotid arterial supply. After a transient improvement, the patient's visual acuity worsened. A follow-up angiogram showed the major supply from the intracavernous internal carotid branches and draining through the inferior ophthalmic vein. The transvenous route was not accessible. An attempt to cannulate the intracavernous branches was not successful. The combined pretemporal and endovascular approach was then used. INTERVENTION: The pretemporal extradural region of the superior orbital fissure was exposed. Using microsurgical techniques and Doppler flow guidance, the anterior cavernous sinus was cannulated through the orbital venous drainage channels. Using intraoperative angiography, thrombogenic coils were deployed at the level of the fistula. Intraoperative angiography confirmed complete obliteration of the fistula. CONCLUSION: The combined pretemporal (extradural) and endovascular approach to the cavernous sinus is a less invasive alternative for the treatment of intractable carotid-cavernous dural fistulae.