Perimedullary Arteriovenous Fistula Research Articles

Perimedullary Arteriovenous Fistula of the Filum Terminale

Although a dural or intramedullary arteriovenous fistula involving the conus medullaris and fed by the lateral sacral artery has been reported, a case of perimedullary fistula arising from an artery in the filum terminale has not been described in the literature. The authors report the first case of perimedullary arteriovenous fistula located in the filum terminale. A 61-year-old man presented with a 10-year history of leg pain. Thoracolumbar magnetic resonance imaging scans revealed multiple perimedullary signal voids from T10 to L3. Angiography showed engorged perimedullary veins and a fistula fed by the anterior spinal artery from the right ninth segmental artery and by 2 branches of the left lateral sacral artery. The anterior spinal artery was also regarded as the artery of the filum terminale. Transarterial embolization was performed to occlude the feeders from the left lateral sacral artery, and an L5 total laminectomy was subsequently performed to obliterate residual fistulous material from the artery of the filum terminale. The thickened, yellowish filum, surrounded by tortuous, engorged veins, was coagulated and resected. Postoperatively, the patient's symptoms gradually resolved and were not aggravated during long periods of walking. It must be noted that a fistula can be located in the filum terminale and can be successfully treated using multidisciplinary approaches.

The value of 64-slice CT angiography in diagnosing spinal vascular malformations

Objective To evaluate 64-slice CT angiography in diagnosing spinal vascular malformations. Methods Fifteen patients,who were suggestive of spinal vascular malformations bv clinical manifestation and MRI,underwent CT angiography with a 64-slice spiral CT(GE lightspeed VCT).DSA were performed later within 1 week in all the patients and four of them were treated with operation as well.We evaluated CTA images in displaying the lesions according to the following aspects:the type of malformation,lesion range,feeding artery,draining vein and possible fistula.and compared those details with DSA and operation findings.Results All 15 patients acquired their final diagnosis by DSA and operation,which were intramedullary axteriovenous malformation in 6 cases,perimedullary arteriovenous fistula in 2,spinal dural arteriovenous fistula in 3 and Cobb syndrome in 4 cases. CTA was consistent with DSA in the classification of lesions and in the determination of the involved regions and it reveaIed the main feeding arteries and draining veins in all patients.CTA showed four arteriovenous fistulae confinned bv DSA.but it failed in a complex arteriovcnous fistula.In Cobb syndrome patients,not only the intramedullary but also paravertebral and subcutenous vascular malformation could be clearly seen on CTA images.Conclusion 64-slice CT angiography can be a preliminary method in spinal vascular malformation because it can determine the classification and reveal almost all the main lesions quickly,atraumatically. Key words: Central nervous system vascular malformations; Tomography,X-ray computed

Clinical characteristic of spinal vascular malformation in pediatric patients

Seventy-two pediatric spinal vascular malformation cases were reviewed and the characteristics of their clinical symptoms, diagnoses, and therapies were analyzed. A thorough overview was compiled examining patient sex, age, location, history, development, treatment, clinical, and anatomical results. Spinal cord arteriovenous malformation was the most common (44.4%) subtype to be seen in these pediatric patients, while subdural perimedullary arteriovenous fistula (23.6%) was the second, followed by Cobb's syndrome (13.9%) and intramedullary cavernous angioma (5.6%). No spinal dual arteriovenous fistulae were found in infants. The highest incidence was seen during the infant and adolescent periods. Sixty-nine cases were treated by surgeries, embolizations, or a combination of both, and 71.5% of them had improved. Early diagnosis and treatment are required. Surgery and embolization, or a combination of the two, are the current candidates for treatment.

Conus perimedullary arteriovenous fistula in a child: unusual angio-architectural features and pathophysiology

The perimedullary arteriovenous fistulas are located on the pial surface and are usually supplied by spinal medullary arteries, that is, either by the anterior or posterior spinal arteries, with no intervening nidus between the feeder arteries and the venous drainage. The clinical findings are, more commonly, caused by progressive radiculomedullary ischemic processes secondary to steal vascular mechanism. As the vascular supply to the spinal cord and to the arteriovenous fistulas (AVF) is not shared with one another, the vascular steal phenomenon cannot be implicated in this case's physiopathology. Most probably, the mass effect caused by the giant venous dilatation was the pathophysiological mechanism involved in this lesion. The authors describe the case of a 6-year-old girl with an intradural ventral arteriovenous fistula, with a giant venous dilatation, fed directly by L2 and L3 radiculomedullary arteries at the conus medullaris. There was no arterial supply to the fistula from the anterior or posterior spinal arteries. Selective spinal angiography showed an arteriovenous fistula supplied directly by two radiculomedullary arteries, with a large draining vein caudally. Interposing the arterial and venous vessels was a giant venous aneurysmal dilatation located ventral to the conus medullaris and extending from L3 to T6. The patient was successfully treated by a surgical approach through a laminotomy from L3 to T11. The type IV-C spinal arteriovenous malformations or perimedullary AVFs are rare lesions predominately described at the conus medullaris with various types of angio-architecture and controversial treatment.

Cervical Perimedullary Arteriovenous Fistula in an Infant Presenting With Subarachnoid Hemorrhage -Case Report-

A 9-month-old boy was transferred to our institute after suffering sudden seizure and loss of consciousness followed by cardiopulmonary arrest. Neurological examination on admission revealed deep coma and tetraparesis. Brain computed tomography revealed diffuse intracranial subarachnoid hemorrhage (SAH), whereas brain magnetic resonance (MR) angiography showed no intracranial abnormalities. MR imaging of the spine demonstrated a remarkable flow void extending from C3 to T1. Digital subtraction angiography revealed a perimedullary arteriovenous fistula (AVF) fed by the left thyrocervical trunk, associated with a varix and a dilated perimedullary vein. He had hypoxic encephalopathy due to transient cardiopulmonary arrest, and remained in the intensive care unit for 2 months. Thereafter, he was transferred to the pediatric ward, where his general condition improved, and after 7 months underwent embolization of the AVF to prevent further SAH. The perimedullary AVF was successfully interrupted by transarterial embolization with n-butyl-2-cyanoacrylate and platinum coils, and no additional neurological deficits developed. Post-embolization MR imaging showed loss of the flow void. The favorable outcome demonstrates the importance of spinal cord imaging in infants with SAH without other intracranial abnormalities to detect the presence of perimedullary AVF. Perimedullary AVFs in children are often associated with huge fistulas and varices, so are good candidates for endovascular surgery.

Intracranial Pial Arteriovenous Fistulas

Intracranial pial arteriovenous fistula (AVF) is a rare cerebrovascular lesion that has only recently been recognized as a distinct pathological entity. A 41-year-old woman (Patient 1) presented with the sudden development of an altered mental state. Brain CT showed an acute subdural hematoma. A red sylvian vein was found intraoperatively. A pial AVF was revealed on postoperative angiography, and surgical disconnection of the AVF was performed. A 10-year-old boy (Patient 2) presented with a 10-day history of paraparesis and urinary incontinence. Brain, spinal MRI and angiography revealed an intracranial pial AVF and a spinal perimedullary AVF. Endovascular embolization was performed for both lesions. The AVFs were completely obliterated in both patients. On follow-up, patient 1 reported having no difficulty in performing activities of daily living. Patient 2 is currently able to walk without assistance and voids into a diaper. Intracranial pial AVF is a rare disease entity that can be treated with surgical disconnection or endovascular embolization. It is important for the appropriate treatment strategy to be selected on the basis of patientspecific and lesion-specific factors in order to achieve good outcomes.

Transarterial balloon-assisted glue embolization of high-flow arteriovenous fistulas

We report here our experience in treating high-flow arteriovenous fistulas (AVFs) of the brain and spine using balloon-assisted glue injection. During a 3-year period (2003-2005) five patients with high-flow AVFs were treated at our hospital using transarterial balloon-assisted glue injection. There were two pial AVFs, one dural AVF, one vein of Galen malformation and one perimedullary AVF of the cervical spine. All patients were clinically followed-up for 12-48 months. Immediate angiographic obliteration was achieved in all patients. The fistulas remained closed in all patients, as ascertained by follow up-angiograms. No new neurological deficits related to the procedure were detected. Clinically, one patient with severe pre-treatment neurological deficit experienced excellent recovery. Transarterial balloon-assisted glue embolization of high-flow AVFs is a feasible and efficient treatment. This technique affords more control in the glue injection and minimizes the risk of distal embolization.

The Validity of Intraoperative Angiography for the Treatment of Spinal Arteriovenous Fistula

Retrospective study of patients with spinal arteriovenous fistula (AVF) who underwent surgical treatment. To evaluate the validity of the intraoperative angiography (IA) for the surgical treatment of spinal AVF. Owing to the development of interventional techniques, endovascular embolization has become the treatment of choice for AVF, but it is not applicable for every spinal AVF owing to anatomic complexity of the spinal cord vessels. To get effective occlusion of the AVF, IA has been routinely used in the management of cerebral vascular diseases, but report of its use for spinal AVF is rare. Since 2004, 4 consecutive cases of spinal AVF (3 males and 1 female, 3 thoracic, and 1 thoracolumbar) were involved in this study. The mean age at the time of operation was 62.3 years (range from 48 to 76 y). Types of AVFs and surgical techniques were reviewed retrospectively and the outcomes were assessed using the Japanese Orthopedic Association scoring system. AVFs in 3 patients were diagnosed as the dural type and that in the remaining patient as the perimedullary type; all feeding arteries were derived from the ninth to 10th intercostal arteries. Preoperative angiography demonstrated that the feeding arteries in 2 patients with a dural AVF were the branches of Adamkiewicz artery and in another dural AVF case, the Adamkiewicz artery could not be determined, therefore, endovascular embolization was not feasible. Including a patient with perimedullary AVF, a microsurgical clipping combined with IA was selected as the treatment. Complete occlusion of the fistula was achieved in all cases, the mean preoperative Japanese Orthopedic Association score of 4.5 improved to 6 at the final follow-up, and no perioperative complications were observed during the follow-up period. The favorable clinical results in our spinal AVF cases confirmed that IA ensures safe and accurate occlusion of the fistula. This technique provides satisfactory surgical results for spinal AVFs.

Multi-detector-row CT angiography as a preoperative evaluation for spinal arteriovenous fistulae

The role of multi-detector-row computed tomographic angiography (MDCTA) in spinal vascular malformations has not yet been determined. We present a report on a short series of spinal arteriovenous fistulae (AVF) evaluated by MDCTA. With 4-row and 16-row MDCTA, three cases of spinal dural AVF and one case of perimedullary AVF were examined. Each case was also examined by magnetic resonance (MR) imaging and spinal catheter angiography. In two patients with spinal dural AVF, including one patient with angiographically occult AVF, MDCTA successfully located the site of the AVF in a multi-planar reformation image. MDCTA failed to locate the remaining case of spinal dural AVF, probably due to the small amount of shunting blood volume at the fistula. In a patient with perimedullary AVF, MDCTA visualized the broad range of the lesion, including the anterior spinal artery as a single feeder, the fistulous point, and the single perimedullary draining vein. In conclusion, although conventional spinal angiography might be still essential, MDCTA provides useful information for the surgeon in treatment of the spinal dural AVF. Further accumulation of clinical cases is required to determine the potential of MDCTA for perimedullary AVF. MDCTA should be considered as a choice of investigation in the evaluation of spinal AVFs.

Successful embolization of a giant perimedullary arteriovenous fistula of the cervical spine in a 6-year-old child

We report a case of a 6-year-old boy with a giant perimedullary arteriovenous fistula of the cervical spine who presented with progressive tetraparesis. Transarterial glue embolization was performed and complete occlusion of the fistula was achieved. The patient's symptoms resolved completely during the next year.

The initial clinical application of multi-detector CT on spinal angiography

Objective To explore the value of Multi-detector CT in spinal cord angiography. Methods Ten patients with initial MR and clinical findings suggestive of spinal cord vessel disease were performed CT spinal cord angiography.Among these,7 patients were performed DSA later within 1 week, and 4 patients were therapy by operation.CT protocol:Toshiba Aquilion 64 slice CT scanner,0.5 mm thickness,0.5/r,120 kV,350 mA,choose aortic arch level as inspection position,and usesurestart technique with CT threshold 180 HU.Contrast medium was Iohexol(370 mg I/ml),with injection velocity of 6 ml/s.The total volume was 80 ml.The CT spinal cord angiography images were analyzed according to disease model,disease range,feeding artery,fistula,draining veins,and were compared with DSA and operation results.Results All CT spinal cord angiography images displayed spinal vessel malformation. Among these,3 patients were inner-medullary arteriovenous malformation;2 patients were peri-medullary arteriovenous fistula;5 patients were spinal dural arteriovenous fistula.All cases showed disease range,and draining veins clearly,one patient had two vessels that were false positive,and all the other cases showed feeding arteries clearly,which were confirmed by DSA.Conclusion There are great values for CT spinal angiography in diagnosing spinal vessel disease,it can be a screening exam before DSA.

Spinal arteriovenous malformations: new classification and surgical treatment

Spinal vascular malformations represent rare and insufficiently studied pathological entities characterized by considerable variation. Insufficient study of this disease is connected with the complexity of its diagnosis, which restricts the development of surgical treatments that are differentiated according to the type of malformation. Great difficulties are caused by the lack of a clear structural-hemodynamic classification of spinal arteriovenous malformations (AVMs). At present the classification created between 1991 and 1998 by the combined efforts of different authors is the most widely used one. According to this classification, four categories are distinguishable: Type I, dural arteriovenous fistulas (AVFs); Type II, intramedullary glomus AVMs; Type III, juvenile or combined AVMs; and Type IV, intradural perimedullary AVFs. Vascular tumors are also classified, as follows: hemangiomas, hemangioblastomas, angiosarcomas, hemangiopericytomas, angiofibromas, angiolipomas, and hemangioendotheliomas, as well as cavernous malformations. In this study the authors analyze the diagnostic data and results of treatment in 91 patients with AVMs and AVFs who were treated at the Institute of Neurosurgery between 1995 and 2005. The patients' ages ranged from 9 to 83 years; the mean age was 42.9 years. For spinal vascular malformations we devised a classification that took into account the aforementioned features of AVMs: the anatomical characteristics of a malformation and its angiostructural and hemodynamic features. In all patients the neuroimaging modalities used in the investigation of their lesions included magnetic resonance (MR) imaging and selective spinal angiography. Three-dimensional computerized tomography angiography studies were obtained in 14 patients, and MR angiography was used in 17. For successful surgical treatment of spinal AVMs it is necessary to obtain data about their localization, vascular structure, and hemodynamics that are as complete as possible. This information will promote the use of optimum surgical procedures and the latest methods of microsurgical and endovascular interventions, with treatments differentiated according to the type of malformation. One should try to use the least invasive endovascular approach in these cases,where possible, to occlude the AVM or reduce the intensity of blood flow by means of embolization. To perform an AVM resection or occlusion, one should use a direct approach to the malformation, blocking only the vessels supplying blood to the malformation and preserving the vessels feeding the spinal cord.

Congestive Myelopathy Due to Cervical Perimedullary Arteriovenous Fistula Evaluated by Apparent Diffusion Coefficient Values-Case Report-

A 22-year-old woman presented with a cervical perimedullary arteriovenous fistula (AVF) manifesting as right upper and lower extremity weakness. T2-weighted magnetic resonance (MR) imaging showed intramedullary hyperintensity believed to be caused by venous congestion. Preoperative diffusion-weighted MR imaging showed increased apparent diffusion coefficient (ADC) value. Spinal angiography demonstrated an AVF fed mainly by the right C-5 radicular artery. Complete obliteration of AVF was achieved by endovascular embolization and microsurgical shunt occlusion. The ADC value was normalized and her neurological deficits improved after endovascular surgery, whereas T2-weighted MR imaging still demonstrated the lesion. The high preoperative ADC value probably indicated reversible vasogenic edema and immediate normalization of the ADC value suggests a good clinical outcome.

Split cord malformation with associated Type IV spinal cord perimedullary arteriovenous fistula

The authors describe the case of a 62-year-old woman with a Type II split cord malformation (SCM). At the initial time of workup, the authors observed an associated Klippel-Feil deformity at the level of the SCM and a low-lying conus medullaris; however, they discovered an associated Type IV perimedullary spinal cord arteriovenous fistula (AVF) only after the patient continued to deteriorate following a spinal cord untethering procedure. Although prominent blood vessels have been reported within the median cleft of SCMs, an angiographically and surgically proven perimedullary AVF has not previously been described. The potential coexistence of SCM and perimedullary AVF has significant clinical implications and its recognition is critically important prior to surgical treatment.

Spinal aneurysm arising from the feeding pedicle of a thoracic perimedullary arteriovenous fistula: case report

Background Aneurysms of the spinal artery are exceedingly rare. We report on the first case of a pathologically proven aneurysm arising from the feeding pedicle of a perimedullary arteriovenous fistula (AVF). Case Description A 42-year-old man presented with subarachnoid hemorrhage (SAH) and spinal angiography demonstrated a thoracic perimedullary AVF fed by the left T8 intercostal artery that also harbored a spinal aneurysm. He underwent laminectomy 18 days postonset. The aneurysm was resected and the fistula was interrupted. Conclusion For appropriate treatment planning, it is necessary to rule out the presence of aneurysms on the feeding vessel in patients with spinal perimedullary AVF who present with SAH.

Treatment of Spinal Cord Perimedullary Arteriovenous Fistula: Embolization versus Surgery

To provide the optimal treatment strategy for perimedullary arteriovenous fistula (PMAVF). Nineteen patients with PMAVF (Type IVa in 9 patients, Type IVb in 6, and Type IVc in 4) were treated at Seoul National University Hospital between January 1988 and March 2001. Their mean age was 28 years (range, 6-52 yr), and the male-to-female ratio was 1.7:1. The mean follow-up period was 20 months (range, 2-55 mo). Most patients presented with symptoms of slowly progressive myelopathy (13 patients). On spinal angiography, all but 2 showed fistula at the level of the conus medullaris. The feeder was the anterior spinal artery and/or the posterior spinal artery in 14 patients and the posterior spinal artery in 5. All patients underwent endovascular or surgical treatment. With endovascular treatment (11 patients; IVa, n = 5; IVb, n = 2; IVc, n = 4), complete angiographic obliteration of fistula was performed in 5 and partial obliteration in 4 (IVa, n = 1; IVb, n = 2; IVc, n = 1). Symptomatic improvement or arrest of progression was achieved in 5 of 9 patients with complete or partial occlusion. Embolization failed in two (IVa, n = 1; IVc, n = 1). With surgery (10 patients [IVa, n = 6; IVb, n = 4], including 2 patients with partial or failed embolization), most (9 of 10) were improved or stable. Good results were achieved with surgery for Types IVa and IVb PMAVF located at the level of the conus medullaris. For Type IVc PMAVF, a fistula located on the ventral side of the spinal cord or above the conus medullaris, endovascular treatment might be considered. Because of rapidly evolving endovascular techniques, however, further studies are warranted.

Intraoperative Color Doppler Sonography in the Surgical Treatment of Perimedullary Arteriovenous Fistula-Case Report-

A 36-year-old female was treated for a perimedullary arteriovenous fistula (AVF) using intraoperative color Doppler sonography monitoring. Color Doppler sonography before interruption of the fistulous point clearly demonstrated an abnormal hyperechoic lesion. After interruption of the shunting point, the lesion had disappeared. Intraoperative angiography confirmed the disappearance of the perimedullary AVF. Intraoperative color Doppler sonography is a noninvasive, reliable, and cost-effective method for monitoring the effect of interruption on perimedullary AVF.

頭蓋頚椎移行部動静脈ろうの検討

We report 6 patients with rare arteriovenous fistulas of the craniocervical junction: 5 men and 1 woman ranging in age from 54 to 75 years. All manifested associated subarachnoid hemorrhage. Angiography demonstrated that 4 of the 6 fistulas were spinal dural arteriovenous fistulas (SDAVF) fed by the meningeal branch of the vertebral artery, the other 2 were spinal perimedullary arteriovenous fistulas (SPAVF) fed by the anterior spinal artery. Drainage was via the perimedullary vein of the craniocervical junction. Retrograde leptomeningeal venous drainage (RLVD) into the intracranial venous system was recognized in 5 cases; in 3 the draining system contained varices. All 6 patients underwent direct surgery using the transcondylar fossa approach. Before proceeding to surgical coagulation, intraoperative angiography proved useful for the temporary clipping to the feeding artery in our SPAVF cases or the drainer in the SDAVF cases. The postoperative course of 5 patients was good; the other patient remained moderately disabled due to initial damage of the medulla oblongata. SPAVF and SDAVF in the craniocervical junction led to subarachnoid hemorrhage and the presence of RLVD into the intracranial venous system was related to the hemorrhagic symptoms. By direct surgery a good prognosis can be achieved in patients with arteriovenous fistulas of the craniocervical junction.

Angiography-induced closure of perimedullary spinal arteriovenous fistula

Type 4 spinal vascular malformations are called perimedullary arteriovenous fistulae, in which there is a shunt between a radicular artery and intradural veins. We report the spinal MR imaging and angiography findings of the angiography-induced closure of a type 4 spinal vascular malformation.

Usefulness of Multidetector 3D-CT Angiography in the Evaluation of Infantile Perimedullary Spinal Arteriovenous Fistula.

We report an infantile huge perimedullary spinal arteriovenous fistula (SAVF) associated with Hereditary-Hemorrhagic-Telangiectasia (HHT), which was treated by glue embolization in one session. Three-dimensional Multidetector Computed Tomography Angiography (3D-MCTA) was useful in pre- and post-endovascular intervention.