Pseudoaneurysm formation following transarterial embolization of traumatic carotid-cavernous fistula with detachable balloon: An institutional cohort long-term study.

BACKGROUND: The goal of therapy for traumatic carotid-cavernous fistula (TCCF) is the elimination of fistula while maintaining patency of the parent artery. The treatment for TCCF has evolved from surgery to endovascular management using detachable balloons, coils, liquid embolic agents, covered stents, or flow-diverter stent through arterial or venous approaches. Despite the withdrawal of detachable balloons from the market in the United States since 2004, transarterial embolization with detachable balloons has currently remained the best initial treatment for TCCF in several countries. However, the pseudoaneurysm formation following transarterial detachable balloon embolization has rarely been observed in long-term follow-up. AIM: To determine the occurrence and long-term follow-up of pseudoaneurysm after transarterial detachable balloon for TCCF. METHODS: Between January 2009 and December 2019, 79 patients diagnosed with TCCF were treated using detachable latex balloons (GOLDBAL) of four sizes. Pseudoaneurysm sizes were stratified into five grades for analysis. Initial and follow-up assessments involved computed tomography angiography at 1 month, 6 month, 1 year, and longer intervals for significant cases. Clinical follow-ups occurred semi-annually for 2 years, then annually. Factors analyzed included sex, age, fistula size and location, and balloon size. RESULTS: In our cohort of 79 patients treated for TCCF, pseudoaneurysms formed in 67.1%, with classifications ranging from grade 0 to grade 3; no grade 4 or giant pseudoaneurysms were observed. The majority of pseudoaneurysms did not progress in size, and some regressed spontaneously. Calcifications developed in most large pseudoaneurysms over 5-10 years. Parent artery occlusion occurred in 7.6% and recurrent fistulas in 16.5%. The primary risk factors for pseudoaneurysm formation were identified as the use of specific balloon sizes, with balloon SP and No. 6 significantly associated with its occurrence (P = 0.005 and P = 0.002, respectively), whereas sex, age, fistula size, location, and the number of balloons used were not significant predictors. CONCLUSION: Pseudoaneurysm formation following detachable balloon embolization for TCCF is common, primarily influenced by the size of the balloon used. Despite this, all patients with pseudoaneurysms remained asymptomatic during long-term follow-up.

De novo formation of remote dural arteriovenous fistula following treated cavernous sinus dural arteriovenous fistula.

Background: The development of new dural arteriovenous fistulas (DAVFs) at another location following endovascular treatment of cavernous sinus DAVFs (CSDAVFs) are extremely rare. Our aim is to review cases of de Novo DAVFs that occurred after treatment of CSDAVFs at our institution and those reported in the literature. Methods: We reviewed all cases of CSDAVFs evaluated by 2 experienced neuroradiologists. A literature search was performed using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines focusing on De Novo DAVFs following the endovascular treatment of cerebrovascular malformations. Addition articles were searched through the reference lists of the included articles. Results: From June 2004 and September 2019., we identified 3 (2.5%) cases of De Novo DAVFs occurred after endovascular treatment or spontaneous obliteration of CSDAVFs from 119 treated CSDAVFs at our institute. Our review yielded 9 articles involving 12 patients with 15 de novo DAVFs, including our 3 patients. The mean age was 55.08 ± 12.9 years (range 43-69), 83.3% were females (n = 10). The new remote DAVFs occurred after endovascular treatment of CSDAVFs in 10 (83.3%) patients. The de novo DAVFs occurred following spontaneous complete regression in 2 (16.7%) patients. All de novo DAVFs developed after complete obliteration of treated CSDAVFs. Conclusion: Sinus thrombosis and elevated venous pressure may play an important role in the pathogenesis of a de novo DAVF formation. In addition, thrombophilic abnormalities and the use of contraceptives may contribute to sinus thrombosis, leading to the development of the second remote DAVF after treatment of CSDAVFs.

Dural arteriovenous fistula involving superior petrosal sinus with petrosal venous drainage in association with cerebral venous thrombosis: Literature review and illustrative case.

Background: Dural arteriovenous fistulas (DAVFs) involving superior petrosal sinus (SPS) and superior petrosal vein (SPV) are extremely rare. The pathogenesis of these fistulas remains unclear. We are illustrating 2 cases of DAVFs involving the superior petrosal sinus and veins associated with venous sinus thrombosis with a literature review. Methods: We reviewed the literature using the PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines focusing on DAVFs involving the SPS and/or SPV. Additionally, we searched for additional articles through the reference lists of the included studies. Results: Our review yielded 20 articles from 1997 until 2022 involving 33 patients with 34 fistulas, including our 2 patients. The mean age was 55.1 ± 12.9 years (range 25-85), 54.5% were males (n = 18). The patients presented with hemorrhage in 36.4% (n = 12), and progressive myelopathy in 30.3% (n = 10). Most fistulas often had arterial supply from MMA, MHT, and/or OA. The fistulas had infratentorial drainage in 64.71% (n = 22), supratentorial drainage in 23.53% (n = 8), and both supra and infratentorial drainage in 11.76% (n = 4). In 27.3% (n = 9), cerebral venous thrombosis was mentioned or identified. Endovascular treatment was performed in 47.1% of cases (n = 16), surgery in 29.4% (n = 10), and combination of treatments in 23.5% (n = 8). A total of 30.3% (n = 10) of cases had incomplete recovery or poor result. Conclusion: DAVFs involving the SPS and/or SPV are associated with aggressive natural history, requiring early diagnosis and prompt treatment, leading to good prognosis. These fistulas may be acquired in origin, probably secondary to cerebral venous thrombosis.

Spontaneous complete regression of malignant cavernous sinus dural arteriovenous fistula following partial transarterial embolization with liquid embolic material: Report of two cases.

Background: Spontaneous complete regression of malignant cavernous sinus dural arteriovenous fistulas (CSDAVFs) following partial transarterial embolization is an extremely uncommon phenomenon. The mechanism responsible for this condition remains unclear. Case Description: The authors describe two cases of malignant CSDAVFs (Cognard IIb and V) treated by partial transarterial embolization with liquid embolic agents after unsuccessful transvenous embolization through various routes. Follow-up cerebral angiography in these cases confirmed complete resolution of the fistulas. Conclusion: In our two patients harboring low-flow CSDAVFs with preexisting thrombosis of the cavernous sinus (CS), it is possible that some portions of the liquid embolic materials could migrate into the fistulas, inducing thrombosis within the CS.

Dural arteriovenous fistula of the craniocervical junction along the first cervical nerve: A single-center experience and review of the literature.

BACKGROUND: Dural arteriovenous fistulas (DAVFs) of the craniocervical junction (CCJ) are relative rare lesions. Most studies of DAVFs of the CCJ included the fistulas at the foramen magnum, first cervical (C1), and second cervical (C2) level. DAVFs of the CCJ along C1 spinal nerve are rare vascular lesions with distinctive features. Our aim is to review cases of DAVFs of the CCJ along C1 spinal nerve at our institution. METHODS: From June 2008 and December 2021. We reviewed a consecutive series of intracranial and spinal DAVFs at our institution and collected all patients harboring DAVFs of the CCJ along C1 spinal nerve. Medical charts were retrospectively reviewed regarding patient demographic data (i.e., gender and age), presenting symptoms and signs, treatment methods, and neurological outcome and complications after treatment. All image studies, including cranial computed tomography (CT) scan, cervical magnetic resonance imaging, CT angiography, and digital subtraction angiography (DSA) with rotational CT angiography were analyzed by experienced neuroradiologists. The authors also review of the literature of DAVFs of the C1 spinal nerve. RESULTS: The authors identified 7 patients, including 5 men (71.4 %) and 2 women (28.6 %) with median age 54 years, range 48-72 years. Subarachnoid hemorrhage (SAH) occurred in 5 (71.4 %) patients, and progressive myelopathy in 2 (28.6 %). All fistulas except one received blood supply from the radiculomeningeal branch of the VA at C1 level. Venous aneurysms, being the source of bleeding, were detected in all fistulas with SAH. All patients except one were treated by surgical management. One fistula was treated by balloon-assisted Onyx embolization. Most patients had good neurological outcome following surgery. Complete obliteration of all fistulas treated by surgery was confirmed by follow-up DSA obtained 1 week after surgery. Two patients developed temporary pain and spasm of the trapezius muscle after the surgery. One patient resulted in poor neurological outcome and died due to sepsis and acute upper gastrointestinal bleeding one month after failed embolization. For patients with SAH, only one patient required ventriculoperitoneal shunt. CONCLUSIONS: DAVFs of the CCJ along the first spinal nerve are rare and a unique subtype of DAVFs at the CCJ. These fistulas account for 1.74 % of all intracranial and spinal DAVFs in the present study. SAH is the major manifestation of DAVFs at C1 spinal nerve that may be overlooked on routine initial DSA. Rotational CT angiography is useful for clarification of the angioarchitecture of these fistulas, including small feeding artery and venous varix. Surgical treatment by interruption of the intradural draining vein should be the treatment of choice for C1 spinal nerve DAVF.

Preoperative Transarterial Embolization of a Large Petrotentorial Angiomatous Meningioma Using Combination of Liquid Embolic Materials: A Case Report.

Intracranial angiomatous meningiomas are a rare WHO grade I histological variant of meningioma whose vascular component exceeds 50% of the total tumor area. Preoperative embolization of angiomatous meningiomas has rarely been reported previously. A 58-year-old woman was referred to our institute for a large petrotentorial hypervascular tumor presented with progressively worsening right facial paralysis and hearing loss for 6 months. Cranial computed tomography scan and magnetic resonance imaging revealed a large homogenously enhancing multilobulated mass involving middle and posterior cranial fossae with marked brainstem compression. The tumor extended into a right internal auditory canal and labyrinthine structures with destructive changes of bony structures. Magnetic resonance angiography showed hypervascularity in the tumor. Preoperative transarterial embolization using liquid embolic materials was successfully performed with resulting in almost complete devascularization of the tumor. Adequate hemostasis was achieved following gross total resection of the tumor (Simpson grade II). A histopathological examination confirmed the diagnosis of an angiomatous meningioma. Preoperative transarterial embolization of angiomatous meningioma with liquid embolic material was safe and effective in reducing perioperative blood loss and facilitating total tumor resection.

Revascularization of the internal carotid artery through the hypertrophied vasa vasorum in traumatic carotid-cavernous fistula previously treated by ligation of cervical carotid arteries: A case report.

Background: Revascularization of the occluded internal carotid artery (ICA) through the vasa vasorum is exceedingly rare. Several previous studies hypothesized that the expansion of the vasa vasorum is associated with neovascularization related to the progression of atherosclerosis or plaque. The occurrence of reconstitution of the ICA through the vasa vasorum in traumatic carotid-cavernous fistula (TCCF) has rarely been reported. Case Description: We described an extremely rare case of a 64-year-old woman who developed reconstitution of the occluded ICA through hypertrophied vasa vasorum supplying recurrent TCCF previously treated by ligation of the internal and external carotid arteries. Usual endovascular treatment may be challenging for this patient due to inaccessible route from the affected ICA through multiple small vessels. The patient was successfully treated with trapping procedure and obliteration the fistula using combined surgical and endovascular treatment. Conclusion: We speculated that the hypertrophied vasa vasorum in TCCF may cause by a sequela of previous arterial injury, spontaneous recanalization of the occluded artery by the formation of vasa vasorum, and/or hypertrophy of the vasa vasorum due to the high flow of the fistula.

Combined endovascular and microsurgical management of complex traumatic carotid-cavernous fistula: Three case reports.

Background: With the evolution of the endovascular devices, the management of endovascular interventions has become the current standard therapy for traumatic carotid-cavernous fistula (TCCF). However, only endovascular treatment may not be feasible in some patients with atypical TCCF. Case Description: We described three complex TCCFs that could not be managed by conventional endovascular methods. The first patient had recurrent TCCF previously treated by muscle embolization and ligation of affected carotid arteries 23 years ago. Another two patients had TCCFs association with large pseudoaneurysm within the sphenoid sinus. In each patient, the fistula was successfully closed by trapping procedure using a combination of endovascular and surgical treatment. Conclusion: To reduce costs of treatment, trapping operation by combining surgical and endovascular treatment may be considered as an alternative option for complex TCCF which has some features including chronic stage, preexisting carotid artery ligation, or association with large venous pouch of the cavernous sinus or sphenoid sinus pseudoaneurysm.

Acquired Chiari malformation Type I and holocord syringomyelia associated with a high-flow supratentorial fistulous arteriovenous malformations: A case report and literature review.

Background: Chiari malformation Type I (CMI) is generally considered a congenital lesion and typically associated with syringomyelia. Acquired CMI or adult Chiari malformation caused by intracranial mass is extremely rare. Brain arteriovenous malformations (AVMs) are characteristically symptomatic due to seizure, intracranial hemorrhage, or neurological deficit. We report an extremely rare case of an acquired CMI and extensive syringomyelia associated with a large supratentorial AVM. Case Description: A 35-year-old woman was referred to our institute after a diagnosis of CMI and extensive syringomyelia from whole-spine magnetic resonance imaging (MRI) due to complaining of low back pain radiating to the right leg for the past 1 month. She had intermittent headache for 2 years. The patient underwent suboccipital decompression and C1 laminectomy followed by duraplasty. Two months later, she developed severe right-sided sciatic pain and complete right foot drop. Follow-up MRI revealed progressive enlargement of a syrinx cavity at the lower spinal cord and a large right parieto-occipital AVM with markedly dilated cortical draining veins and diffuse engorgement of dural venous sinuses was detected. This AVM supplied mainly by enlarged cortical branches of the right middle cerebral artery and posterior cerebral artery with multiple dural supplies. Endovascular treatment of a high-flow fistulous AVM was successfully performed with N-butyl cyanoacrylate (NBCA) through the hypertrophic branches of the right middle cerebral artery. Four months after embolization, the patient had recovered completely from the right foot drop. Further staged embolization was planned to reduce the size and flow of the AVM before stereotactic radiosurgery. However, the patient was lost to follow-up due to financial reason. One year later, she developed sudden severe headache followed by alteration of conscious due to intraventricular hemorrhage from the AVM, leading to obstructive hydrocephalus requiring cerebrospinal fluid diversion. During a period of 2 years, the patient underwent several staged embolization with NBCA and Onyx. Final cerebral angiography after embolization demonstrated a significant reduction in size and flow of the brain AVM. A control whole-spine MRI revealed a significant reduction in syrinx size. At the end of embolization, the patient had no neurological deficit. However, she had suffered from persistent central neuropathic pain at the right lower extremity. The AVM remnant was further treated by stereotactic radiosurgery. Conclusion: Increased cerebral venous hypertension secondary to a high-flow supratentorial AVM leading to posterior fossa venous hypertension may play a major role in the pathogenesis of CMI, induced the formation of syringomyelia. Endovascular treatment of brain AVM, the underlying cause of CMI, resulted in a significant reduction of the size of the syrinx. The need for cranial imaging in initial evaluation of cases with adult Chiari malformation is important.

Sacral dural arteriovenous fistula of the filum terminale coexisting with partially thrombosed filum vein: A case report and literature review.

Background: Filum terminale arteriovenous fistulas (FTAVFs) are rare and usually classified as intradural ventral AVFs or Type IVa perimedullary fistulas, located on the pia surface along the course of filum terminale internum (FTI). We report an extremely rare case of sacral dural arteriovenous fistula of the FT. We also review the occurrence of FTAVFs in the sacral region. Case Description: A 64-year-old man presented with progressive weakness of the lower extremities for 3 months and bowel/bladder dysfunction following long history of back pain radiating to both legs. Magnetic resonance imaging of the lumbosacral and thoracic spine showed spinal cord congestion, extending from the conus medullaris to the level of T3, and partial thrombosis within the abnormal tortuous and dilated flow void, running from the sacral area to conus medullaris. Further findings were compression fracture of L2 vertebra, Grade I degenerative spondylolisthesis at the level of L2-3, and L3-4, and spinal stenosis at L2-3, L3-4, and L4-5. Spinal angiography, maximum intensity projection reformatted image of angiographic computerized tomography, and three-dimensional reconstructed image clearly demonstrated dural AVF of the FT at the level of S2 supplied by bilateral lateral sacral and middle sacral arteries with cranial drainage to perimedullary vein through the enlarged vein of the filum. The patient was indirectly treated by transection of the filum terminale and the draining vein at the level of L5 rostral to the fistula. Conclusion: Sacral DAVFs of the FT are extremely rare. In our case, the formation of fistula may cause by venous hypertension secondary to partial thrombosis within the filum vein, probably resulting from long-standing spinal canal stenosis. Sacral FTAVFs may be found on the pia surface of the terminal FTI, dural component at the area of dural sac termination, or dural extension covering the filum terminale externum.

Transfemoral transvenous embolization through the vein of Trolard and superficial middle cerebral vein for cavernous sinus dural arteriovenous fistula with isolated cortical vein drainage: A case report and literature review.

BACKGROUND: Endovascular treatment may be challenging for cavernous sinus dural arteriovenous fistulas (CSDAVFs) with prominent leptomeningeal drainage without other accessible routes. We report a case of CSDAVF with isolated cortical venous successfully drainage treated by percutaneous transvenous embolization through the vein of Trolard and superficial middle cerebral vein (SMCV). We also review the literature of CSDAVFs treated by transvenous embolization through SMCV with or without combined surgical approach. CASE DESCRIPTION: A 46-year-old woman presented with ocular symptoms and delayed treatment was encountered due to the COVID-19 pandemic. Cerebral angiography showed a CSDAVF (Barrow type D, Borden II, and Cognard II a + b) with isolated cortical vein drainage. Percutaneous transvenous access to the fistula through the inferior petrosal sinus was attempted but failed. Transvenous embolization through the vein of Trolard and SMCV was further attempted, and satisfactory occlusion of the fistula was achieved with detachable coils. This access route was chosen because of the occlusion of other access routes and can obliterate the need for more invasive approach, that is, combined surgical and endovascular approach. Cerebral angiography obtained 6 months following the procedure, confirmed complete angiographic obliteration of the fistula. The patient made an uneventful recovery. CONCLUSION: To avoid invasive combined surgical and endovascular approach, transvenous embolization through the vein of Trolard and SMCV may be another accessible option for treating CSDAVF with isolated cortical venous drainage.

Filum Terminale Arteriovenous Fistula Coexisting with a Large L2-L3 Disc Sequestration and Associated Diffuse Lumbar Arachnoiditis.

The authors describe a case of filum terminale arteriovenous fistula (FTAVF) in association with a large L2-L3 disc sequestration and diffuse lumbar arachnoiditis. A 64-year-old male manifested with chronic back pain and gait difficulty. Magnetic resonance imaging (MRI) of the thoracic and lumbosacral spine revealed spinal cord congestion extending from the conus medullaris to the level of T9. There was a large disc sequestration came from L2-L3 disc herniation. In addition, thickening, clumping, and enhancement of the entire cauda equina were noted, probably representing arachnoiditis. MR angiography (MRA) and spinal angiography confirmed FTAVF at the level of L5. The patient underwent laminectomy with lysis adhesions and obliteration of the fistula. His postoperative course was uneventful. MRI and MRA of the thoracolumbar spine obtained 4 months after surgery revealed complete obliteration of the fistula and significant resolution of spinal cord congestion. Enhancement of the cauda equina roots was no longer visible. Interestingly, the significant resorption of the sequestrated disc was documented on MRI. The formation of the FTAVF in the present study may result from severe spinal canal stenosis caused by a large disc sequestration blocking the rostral venous drainage of the fistula, or chronic inflammation, and adhesions of the caudal nerve roots from lumbar arachnoiditis. It seems that FTAVF may be of acquired origin by this evidence.

Filum Terminale Arteriovenous Fistula with Additional Arterial Supply by the Posterior Spinal Artery: A Report of Two Cases.

Filum terminale arteriovenous fistulas (FTAVFs) are rare and usually supplied by the artery of the filum terminale, distal termination of the anterior spinal artery (ASA). These fistulas may also supply from the lateral sacral artery (LSA) arising from the internal iliac artery and/or middle sacral artery. Additional supply by the posterior spinal artery (PSA) has never been mentioned before. The authors describe two middle-aged men harboring FTAVFs manifested with progressive myelopathy and bowel/bladder dysfunction. The first fistula was supplied by the ASA with additional supply by the dilated PSA connecting with the ASA. Another fistula was supplied by the LSA and the PSA communicating with the ASA. The first case was successfully treated by endovascular treatment with N-butyl cyanoacrylate through the enlarged PSA, whereas the second case was surgically treated by direct obliteration of the fistula. Both patients had good neurological outcome.

Spinal epidural arteriovenous fistula with intradural venous reflux: The possibility of acquired origin caused by spinal stenosis and/or disc herniation.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEAVFs) are relative rare lesions. The pathogenesis of these fistulas remains unclear. Our aim is to review cases of SEAVFs at our institution. METHODS: We reviewed a consecutive series of spinal vascular disease at our institution and collected all patients harboring SEAVFs. Medical charts were retrospectively reviewed regarding patient demographic data (i.e., gender and age), presenting symptoms and signs, previous history of spinal surgery or trauma, treatment methods, and neurological outcome after treatment. All image studies, including plain radiography, spinal MRI, MRA, and angiography were analyzed. RESULTS: We identified 9 cases of lumbosacral SEAVFs with intradural venous reflux treated at our institution from June 2010 to August 2020. Their median age was 67 years, range 52-83 years. Only one patient had a history of trauma. Interestingly, our observations found that all fistulas are associated with spinal stenosis and/or disc herniation. An additional literature search about SEAVFs coexisting with spinal stenosis and/or disc herniation was performed and found another 19 cases with median age 69 years, range 39-83 years. Only 2 patients had a history of previous spinal surgery. The level of shunted pouch in all 28 patients was correlated with the level of spinal canal stenosis and/or disc herniation. CONCLUSIONS: Our study may provide an additional evidence supporting an acquired etiology of SEAVFs, which mainly manifest in late adulthood. It is possible that spinal stenosis and/or disc herniation may result in thrombosis or impairment of venous drainage, causing increased venous pressure, leading to fistulous formation.

Intramedullary Hemorrhage Caused by Lumbosacral Epidural Arteriovenous Fistula with Dual Retrograde Perimedullary Venous Draining Routes: A Case Report and Review of the Literature.

BACKGROUND: Spinal epidural arteriovenous fistulas (SEAVFs) are rare lesions with a low risk of hemorrhage. Most patients with lumbosacral SEAVFs with hemorrhagic events will develop a spinal epidural hematoma from epidural venous pouches. To the best of our knowledge, we have reported the first case of a lumbosacral SEAVF presenting with remote intramedullary hemorrhage in the conus medullaris. CASE DESCRIPTION: A 56-year-old man presented with sudden-onset severe paraparesis and bowel/bladder dysfunction. Magnetic resonance imaging of the thoracic and lumbosacral spine showed acute intramedullary hemorrhage in the conus medullaris surrounded by spinal cord congestion extending to T8, with perimedullary flow voids along the ventral and dorsal cord surfaces. Magnetic resonance angiography and spinal angiography confirmed the presence of a SEAVF with a large lumbosacral epidural venous lake supplied by dorsal somatic branches of bilateral L4 segmental arteries. Initially, the intradural venous drainage had been misinterpreted as a single route. The patient underwent surgical interruption of the dilated intradural draining vein after embolization of the feeding vessels. Another small intradural venous drainage route was found on the follow-up angiogram. The second operation with occlusion of the initial part of the epidural venous lake was sufficient to cure this lesion. CONCLUSIONS: With the significant improvement of our patient after treatment of the SEAVF, we speculated that the intramedullary hemorrhage, which had occurred in the area of spinal cord edema, might have resulted from severe venous hypertension, rather than hemorrhagic infarction of the spinal cord. Careful evaluation of the angioarchitecture of SEAVFs is imperative to determine the most effective treatment modality.

Filum Terminale Arteriovenous Fistula in Association with Degenerative Lumbosacral Spinal Canal Stenosis: Report of 3 Cases and Review of the Literature.

BACKGROUND: Filum terminale arteriovenous fistulas (FTAVFs) are rare, and the pathogenesis of these fistulas remains unclear. They may be either congenital or acquired in origin. The authors report 3 cases of FTAVFs in association with severe spinal canal stenosis. The authors also review literature of FTAVFs associated with spinal canal stenosis. CASE DESCRIPTION: All 3 cases harboring FTAVFs manifested with progressive myelopathy and bowel/bladder dysfunction following long history of back pain, sciatica, and/or intermittent claudication. The fistulas were located around or at the level of spinal canal stenosis and supplied by the anterior spinal and/or lateral sacral arteries with cranial drainage from the dilated vein of the filum terminale to the perimedullary veins. The first and third cases were treated concomitantly by performing instrumented fusion with decompressive laminectomy along with occlusion of the fistula with good results. The second case was unsuccessfully treated by endovascular treatment through the lateral sacral artery and denied further surgical treatment. CONCLUSIONS: Our 3 case reports may provide additional evidence supporting an acquired etiology of FTAVFs, probably secondary to the severe central canal stenosis. From our review, the level of the fistulas in most patients is correlated with the level of spinal canal stenosis. The authors preferred the concomitant surgical treatment by performing decompressive laminectomy and obliteration of the fistula in the same surgical session.

Acquired Lumbosacral Spinal Dural Arteriovenous Fistula in Association with Degenerative Lumbosacral Disc Herniation and Spinal Canal Stenosis: Report of Two Cases and Review of the Literature.

The authors describe two cases harboring lumbosacral spinal dural arteriovenous fistulas (SDAVFs) manifested with nonspecific initial symptoms, leading to misdiagnosis and unnecessary procedures. A curvilinear flow void in the lumbar region and thoracic cord congestion with subtle perimedullary flow voids were detected on magnetic resonance imaging (MRI) in both patients. Contrast-enhanced magnetic resonance angiography and spinal angiography confirmed the SDAVFs in the lower lumbar and sacral region. Both fistulas were located at the same level of disc herniation and spinal canal stenosis and supplied by branches of the internal iliac arteries (i.e., iliolumbar and lateral sacral arteries) with cranial drainage from the dilated vein of the filum terminale, corresponding to a curvilinear flow void, to the perimedullary veins. The first case was successfully treated with embolization. Another case had recanalization of the fistula 4 months after endovascular treatment and was successfully treated with surgical interruption of the fistula. Our two case reports may provide additional evidence supporting an acquired etiology of SDAVFs, probably secondary to lumbosacral disc herniation and spinal canal stenosis. The authors also reviewed literature about preexistent lumbosacral SDAVFs associated with disc herniation and spinal canal stenosis. From our review, the level of SDAVFs in most patients is correlated with the level of disc herniation, spondylolisthesis, and/or spinal stenosis.

Spontaneous Closure of a Cavernous Sinus Dural Arteriovenous Fistula with Spinal Perimedullary Drainage (Cognard V) during Attempted Transvenous Embolization.

The authors describe a patient with spontaneous closure of a spontaneous cavernous sinus dural arteriovenous fistula (CSDAVF), Cognard type V, during transvenous attempt. A 39-year-old woman experienced mild proptosis, redness of the left eye, and diplopia. Four months later, she developed left retro-orbital pain and left-sided headache. Cerebral angiography revealed the left CSDAVF exclusively draining into the superior petrosal sinus with subsequent drainage into the veins surrounding the medulla oblongata, and finally into the perimedullary spinal veins, classified as Cognard type V. The feeders arise from the dural branches of both the left external and internal carotid arteries. Following 2 h period of attempted transvenous embolization, the fistula disappeared spontaneously. Follow-up angiography obtained 6 months later confirmed complete resolution of the CSDAVF. At 2-year follow-up, the patient has remained clinically asymptomatic. The mechanism of thrombosis in this fistula related to the endovascular procedure. We speculated that putting the wire tip in the draining vein may induce the spontaneous thrombosis in the venous side. In addition, precipitating factors may include small, low-flow fistula, and pre-existing thrombosis.