Dural arteriovenous malformations(DAVM) or Dural Arteriovenous fistulas(DAVF) consists of multiple arteriovenous shunt between arteries and a dural venous sinuses or a meningeal vein, constitute 10% to 15% of all intracranial arteriovenous malformations Most commonly they involve the transverse, the sigmoid and the cavernous sinuses. Other locations include the tentorial incisure, the superior sagittal sinus, the torcular Herophili, anterior cranial fossa, the convexity dura mater, and the foramen magnum. In angiographic features, leptomeningeal retrograde venous drainage, variceal or aneurysmal venous structure, and galenic venous drainage are significantly associated with aggressive neurological course caused by intracranial hemorrhage(ICH or SAH). Lesion at tentorial incisura and anterior cranial fossa has a tendency to have aggressive neurological course. Dural AVM located at cavernous sinus are classified as 4 types according to arterial distribution. Treatment of Dural AVF or CCF includes conservative monitoring, manual compression, arterial embolization, transvenous occlusion, surgical excision and radiation therapy. Surgical therapy with or without preparatory embolization remains the most versatile and effective therapeutic option. It is usually aimed at resecting the dural leaflets harboring the AVM(and adjacent sinus) and at disconnecting leptmeningeal draining pathways which are typically the source of serious neurological sequelae. In Tentorial AVF or anterior cranial fossa AVF the first choice of treatment is surgery because of difficulty in accessibility through transarterial or transvenous embolization.
Aneurysm ; Arteries ; Arteriovenous Malformations* ; Cavernous Sinus ; Colon, Sigmoid ; Cranial Fossa, Anterior ; Drainage ; Dura Mater ; Fistula* ; Foramen Magnum ; Intracranial Arteriovenous Malformations ; Superior Sagittal Sinus ; Veins

The application of stereotactic radiosurgery for cerebrovascular malformations began in the early 1970s. Despite pooly documented response of vascular malformations to externally fractionated radiotherapy, single fraction, high dose, small-field, focused irradiation of small vascular malformations were found to be effective and non-invasive method to obliterate vascular malformations. During last thirty years, overall role of stereotactic radiosurgery has been established in the management of carefully selected vascular malformations. By 1998 world-wide, more than 20,000 patients had undergone Gamma Knife radiosurgery for arteriovenous malformations. In comparison to other forms of nonsurgical management or surgical excision, stereotactic radiosurgery has number of advantages. In properly selected, small volume AVMs, the total obliteration rate at two years appears to be acceptably high(more than 80%), and is associated with low morbidity(less than 2-3%). In contrast to open surgical removal, radiosurgery is associated with none of the risk of microsurgical resection such as blood loss, infection, acute neurological deficits and operative mortality. And yet, major problem of radiosurgery is that it is still exposed to any potential risk of bleeding during latent period before complete obliteration of arteriovenous malformations. Continuous study and researches are recommended for radiobiological clearance. To solve this problem and to enhance the effectiveness of treatment, new energy source should be developed to reduce latent period until complete obliteration would be secured, while reducing the chance of risk by irradiation. Presently, radiosurgery is applied to other vascular malformations such as cavernous angioma or venous angioma, yet, the result is still subject to controversy. Thus, more rigorous research, clinical experience, and enhanced treatment plan should be sought.
Arteriovenous Malformations ; Hemangioma ; Hemangioma, Cavernous ; Hemorrhage ; Humans ; Mortality ; Radiosurgery ; Radiotherapy ; Vascular Malformations

The goals of embolization of arteriovenous malformations(AVMs) is to reduce the size and decrease the anomalous flow of the vascular malformation to reduce the risk of hemorrhage, so that the curative procedures of surgical resection or radiosurgery can be performed with minimal risk. Endovascular cure rate for AVMs is limited to 5% to 10%, and when some symptomatic relief is desired in a surgically inadvisable AVMs, partial embolization can be performed. In the planning of the managements of AVMs, the thorough interpretation of the angioarchitecture of AVMs is mandatory as not only the natural history of AVMs but also the difficulties and risks of embolization is directly related with it. Hemorrhage from the AVMs is usually related to an associated aneurysm, out flow restriction and pure deep venous drainage. And so the intranidal aneurysm should be obliterated firstly. In the presence of fistulous rapid flow in AVM nidus, the risk of venous side embolic occlusion and resulting hemorrhage is increased. Staged procedure is necessary to avoid rapid hemodynamic changes in regions of chronic ischemia surrounding the AVMs, however delay in definitive treatment allows the recruitment of leptomeningial collaterals and deep perforators, and recanalization of previously embolized pedicle. Recanalization of pre-radiosurgery embolization segment can be a cause of incomplete obliteration after radiosurgery. The management of AVMs is best accomplished by the multimodality treatment that is based on the recognition of these benefits and limits of embolization.
Aneurysm ; Drainage ; Hemodynamics ; Hemorrhage ; Ischemia ; Natural History ; Radiosurgery ; Vascular Malformations*

Since 1983, we have experienced endovascular treatment of intracranial AVMs.2)3) Superselective catheterization of feeding artery, embolization or feeding artery occlusion of the cerebral AVMs have been performed for 73 cases in 134 sessions. Endovascular treatment of intracranial AVMs such as embolization or feeding artery occlusion have been performed for 57 cases of AVMs in 95 sessions. In each time, endovascular approach was performed for two to five feeding arteries, so more than 300 feeding arteries were catheterized by microcatheters or balloon catheters. In this report, we present our experiences of endovascular treatment of intracranial AVMs and discuss embolic materials and the role of endovascular treatment of intracranial. AVMs.
Arteries ; Catheterization ; Catheters

Cavernous malformation(CM) is one of the most common intracranial vascular anomaly. CM have dynamic lesion behavior and various clinical spectrum. Hemorrhagic risk and neurological disability seem to be related to multiple factors, including lesion location, age, gender, state of the reproductive cycle, and previous hemorrhage. Selecting the best treatment modality, each clinical scenario requires the proposal of a distinct management approach aimed at weighing the treatment risk against the best estimate of the cumulative natural risk. Management strategies include expectant follow-up in patients with asymptomatic or inaccessible lesions and microsurgical excision of symptomatic and accessible lesions. Radiosurgery could be applied for the progressively symptomatic lesions in inoperable locations, but the mortality and morbidity due to recurrent hemorrhage during latency period and radiation injury should be concerned.
Follow-Up Studies ; Hemorrhage ; Humans ; Latency Period (Psychology) ; Mortality ; Natural History ; Radiation Injuries ; Radiosurgery ; Risk Management

OBJECTS: The surgical management of large cerebral arteriovenous malformation(AVM) is still one of the most difficult fields in neurosurgery. To select the proper candiate for the surgery and improve the results of surgical management of large AVMs, the analysis of the author's cases and the review of the literstures are performed. METERIAL AND METHODS: During the past 17 years, 111 patients with cerebral AVMs were managed surgically. Among these cases, 23 patients had the large AVMs, more than 5 cm in the greatest diameter. The author analyzes these 23 cases clinically and discusses the natural history, surgical indication, surgical techniques, intraoperative and postoperative complications and their management on the basis of the author's experiences and a review of the literatures. RESULTS: Among 23 cases, 16 cases showed good outcome without any neurological morbidity. 6 cases showed mild neurological morbidity such as a memory disturbance, mild hemiparesis or unchanged patterns of seizure, and 1 case showed dense hemiplegia after surgery. There was no mortality. The surgical management of the large AVMs should be decided very carefully because their natural history is relatively benign. An early arterial phase of an angiogram is very useful in discriminating feeders from nidus. An intraoperative use of Doppler ultrasound miniature probe is useful for making a distinction between feeding arteries and drain veins. Wide opening of the fissures and sulci and follows the feeding arteries to the nidus, removing the nidus along the exact border to the brain, induced hypotension during operation and postoperative period with or without pentothal coma were the key points for the surgical management of large AVMs. CONCLUSION: The surgical management of large AVMs is so difficult that the candidates for surgery should be selected carefully bases on the characteristics of the AVMs and experiences of surgeons. However, with experience and meticulous attention, many of these lesions can be resected without development of any morbidity and mortality.
Arteries ; Arteriovenous Malformations ; Brain ; Coma ; Hemiplegia ; Humans ; Hypotension ; Intracranial Arteriovenous Malformations* ; Memory ; Mortality ; Natural History ; Neurosurgery ; Paresis ; Postoperative Care ; Postoperative Complications ; Postoperative Period ; Seizures ; Thiopental ; Ultrasonography ; Veins

For the management of small intracranial arteriovenous malformation(AVM), various methods were proposed and their clinical outcomes have been analyzed. Microsurgery, radiosurgery, and embolization can be effective for the treatment of small AVM. Small AVM is known to be at a higher risk of bleeding. Therefore, the aim of treatment should be the prevention of neurological deterioration from bleeding. Microsurgery has the advantage of prompt elimination of the risk of rebleeding by complete excision with single procedure. With the advance of microsurgical techniques, small AVM can be cured with minimal neurological deficit. Outcome of microsurgery depends on location, size, and numbers and patterns of draining veins, which mean Spetzler-Martin grades. Stereotactic device guided surgery, preoperative careful evaluation, intraoperative electrophysiological and hemodynamic monitoring, and experienced surgical skills can greatly reduce adverse brain injury and help complete and exact excision of malformations. Radiosurgery has its unique role for the deep seated AVM, but long term outcome remains to be evaluated. In the management of small AVM, surgery should be considered as the first line of treatment, and radiosurgery can be an alternative for the surgically inaccessible lesions.
Brain Injuries ; Hemodynamics ; Hemorrhage ; Microsurgery ; Radiosurgery ; Veins

Posterior circulation aneurysm is difficult to treat because surgical approach is time consuming procedure and the risk of postoperative morbidity is still high due to the infarction as the result of the vascular injuries and direct injury to the brain stem and low cranial nerves. Endovascular occlusion is another treatment option for these aneurysms because the postoperative mortality and morbidity are lower than the direct neck clipping. Recently, treatment strategy is advanced, like combined treatment, emergency endovascular occlusion of the sac and direct neck clipping when the patient condition improves or vise versa. Technical and material developments are also noted, balloon assisted neck plasty, stent with coil are also available and 3D coil is recently innovated. Our 3 year experiences of endovascular treatment for posterior circulation aneurysms will be presented. More long-term follow-up is necessary to evaluate the final results, but technological development can reduce the procedure-related complications and newly designed coil and catheters can improve the results and more patients will be helped by this method.
Aneurysm* ; Brain Stem ; Catheters ; Cranial Nerves ; Emergency Treatment ; Follow-Up Studies ; Humans ; Infarction ; Mortality ; Neck ; Stents ; Vascular System Injuries

No Abstract Available.
Intracranial Aneurysm*

Owing to their rarity and the preferential use of CT scanning in the evaluation of trauma cases, the diagnosis of traumatic aneurysms is usually missed. Because the lesion are mostly false aneurysm resulting from injury to all vascular layer, about 90% of this lesion bleed within first 3 weeks after trauma and one-half of the patients who experience this bleeding die; therefore, early diagnosis and treatment are the most essential. The diagnosis requires a high index of suspicion and subsequent angiography. The diagnosis needs to be entertained in any patient who deteriorates by delayed cerebral hemorrhage in the period after severe closed or penetrating head injury. Angiographically, traumatic aneurysms usually have poorly defined necks, are not usually at bifurcation sites, are irregular shaped, and have delayed filling and emptying of sac. Traumatic aneurysm tend to increase in size, therefore immediate surgical exclusion is recommended. Current alternative treatment of traumatic aneurysms involves occlusion of the main artery through the use of endovascular techniques, with either detachable balloons or GDC. In intolerable case to occlusion test, it need EC-IC bypass surgery before occlusion. Surgery is a treatment of choice for traumatic aneurysms in distal locations. The outcome seems to depend on severity of the initial head injury.
Aneurysm ; Aneurysm, False ; Angiography ; Arteries ; Cerebral Hemorrhage ; Craniocerebral Trauma ; Diagnosis ; Early Diagnosis ; Endovascular Procedures ; Head Injuries, Penetrating ; Hemorrhage ; Humans ; Intracranial Aneurysm* ; Neck ; Tomography, X-Ray Computed