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.

Spontaneous regression of extradural high-flow vascular malformation in spinal arteriovenous metameric syndrome (SAMS): A unique case report.

Background: Spinal arteriovenous metameric syndrome (SAMS) is a rare nonhereditary genetic vascular disorder, involving multiple layers of tissues in the same metameric level. Spontaneous regression of SAMS has never been reported in the medical literature. Case Description: A 42-year-old woman presented with intermittent low back pain for 6 months. Magnetic resonance imaging of the thoracolumbar spine incidentally found clusters of spinal vascular malformations involving spinal cord, vertebral bodies, epidural space, and paraspinal muscles. There was no sign of venous congestion. Magnetic resonance angiography and spinal angiography revealed intradural spinal cord arteriovenous malformation (SCAVM) at the level of T10-11 and extradural high-flow osseous arteriovenous fistula. Due to asymptomatic SAMS and a high risk of anterior spinal arterial compromise during treatment, conservative treatment was considered in our patient. Spinal angiography obtained 8 years after initial angiography demonstrated significant regression of extradural component of SAMS and stable intradural SCAVM. Conclusion: We describe a unique case of SAMS with spontaneous regression of extradural component during a long-term observation period.

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.

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.

Pituitary Hormonal Status after Endoscopic Endonasal Transphenoidal Removal of Nonfunctioning Pituitary Adenoma: 5 years' Experience in a Single Center.

BACKGROUND: This study focuses on hormonal disorder and medical complications postoperative endoscopic endonasal transsphenoidal approach of nonfunctioning adenoma at Prasat Neurological Institute, Bangkok, between January 2013 and December 2017. METHODS AND MATERIAL: Baseline characteristics, clinical complications, and hormonal status data were collected from the patients' medical records and analyzed using the descriptive statistics. RESULTS: There were four surgeons who operated 126 cases, 17 of them were reoperation. The average age of the patients was 49 years old. The average length of stay was 13 days, and average operating time was 134 min. Visual field defect was the most common presenting symptom. Almost all the tumors were classified as pituitary macroadenoma which invaded one or two sellar walls. Total or near total tumor removal was the most extend of resection. There were 61 cases developed early diabetes insipidus (DI), but only 12 cases continue to long-term DI. Seven cases were meningitis. Three cases were death. Out of 83 patients who had preoperative intact hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic pituitary thyroidal (HPT) axis, 2 and 3 of them developed postoperative impair HPA and HPT axis in that order. In addition, among 45 patients who had preoperative impair HPA and HPT axis, 6 of them achieved postoperative endocrinological normalization. CONCLUSION: In preoperative intact pituitary hormone patients, the total or near total tumor removal of non functioning pituitary adenoma may have hypopituitarism during early postoperative period but gradually returned to normal during 4-6 month postoperative period.

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.

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 resolution of direct carotid-cavernous fistulas: case series and literature review.

Spontaneous regression of direct carotid-cavernous fistulas (CCFs) is extremely rare. Most of the patients with direct CCFs are usually treated using endovascular techniques. Spontaneous obliteration of the direct fistulas probably results from thrombosis of the venous drainage and/or cavernous sinus. We report spontaneous closure of nine direct CCFs in nine patients. From literature review, we found another 37 patients with 43 fistulas due to spontaneous obliteration of bilateral lesions in six cases. There was no spontaneous closure in large-sized fistula. The factors associated with spontaneous thrombosis of the fistulas may be low-flow and small-sized fistula, hypotension, severe ocular manifestations, dissections or spasm of carotid artery, and increased intracranial pressure. Spontaneous healing of direct traumatic CCFs should be confirmed with cerebral angiography. Conservative treatment of direct CCFs should be carefully restricted in patients with normal vision or minimal visual impairment, and the patients must be monitored closely for any changes in visual function. Prompt endovascular treatment for complete obliteration of the fistula should be performed in patients with rapidly progressive visual loss. Venous thrombosis can still effect vision and rerouting towards cortical veins remains a concern. Because spontaneous resolution cannot be reliably predicted, the fistula then should be treated rather than waiting for spontaneous thrombosis.

Do Asians have Higher Carotid Bifurcation? A Computed Tomographic Angiogram Study of the Common Carotid Artery Bifurcation and External Carotid Artery Branching Patterns.

INTRODUCTION: Carotid endarterectomy is a major treatment modality for high-grade carotid stenosis. Preoperative identification of the level of the carotid bifurcation and its branching pattern is important in planning for adequate exposure and cross-clamping to achieve hemostasis during the procedure. Most of the previous studies on carotid arteries were performed in cadavers. METHODS: We studied levels of carotid bifurcation compared relatively with the level of the vertebral body and ipsilateral angle of the mandible and its branching pattern using computed tomographic angiogram (CTA) carotid with multiplanar reconstruction and three-dimensional imaging in 100 CTA studies. RESULTS: Most of the carotid bifurcations were located at the level of C3-C4 vertebral body and 12% were considered to be high bifurcation. Carotid bifurcations were located below the angle of the mandible in 83.5%. The superior thyroid, facial, and lingual arteries arose from separate branches of external carotid arteries in 67.7% of samples. Facial arteries arose in common trunk with lingual arteries in 29.2%, much more common than previous cadaveric studies. The lingual arteries arose with superior thyroid arteries in 2%, while occipital arteries had high variations in their branching patterns. CONCLUSIONS: CTA is an effective and reliable modality for preoperative evaluation of the carotid system in patients undergoing carotid endarterectomy and other carotid procedures. Higher percentage of high carotid bifurcation was found in our study, concordant with other Asian cadaveric studies. We assumed that carotid bifurcation of Asian tends to be located slightly higher than those of the Caucasian population.

Medullary Hemorrhage Caused by Foramen Magnum Dural Arteriovenous Fistula Successfully Obliterated using Combination of Endovascular and Surgical Treatments: A Case Report and Literature Review.

The authors describe an extremely rare case of foramen magnum dural arteriovenous fistula (DAVF), Cognard type V, presented with medullary hemorrhage caused by venous varix on the lateral medullary draining vein embedded into the medulla oblongata. Following mild myelopathy for 3 days, a 20-year-old male developed dyspnea, generalized seizures, loss of consciousness, and finally cardiac arrest. After successful resuscitation, computed tomography scan (CT) of the brain was obtained and showed acute medullary hemorrhage. Subsequent magnetic resonance imaging of the brain revealed diffuse venous congestion or edema of the medulla with multiple dilated flow voids surrounding the medulla, more prominent on the left side, with venous varix embedded into the left-sided of the lower medulla. He was sent to the emergency department of the local hospital and intubated promptly. A few minutes later, the patient had a cardiac arrest. Digital subtraction angiography (DSA) demonstrated DAVF of the foramen magnum supplied mainly by dural branches of bilateral hypertrophic posterior inferior cerebellar arteries (PICAs), slightly by the posterior meningeal branch of the left vertebral artery, and the jugular branch of the left ascending pharyngeal artery (APA) originating from the occipital artery. Transarterial embolization through the bilateral dural branches of the PICAs was successfully performed using N-butyl-2-cyanoacrylate (NBCA), resulting in complete obliteration. The patient had excellence recovery and lost to annual follow-up. Seven years later, he had a recurrent of the fistula presented with occipital headache. DSA with angiographic CT in three-dimensional reconstruction and maximum intensity projection reformatted images clearly demonstrated the exact location of the DAVFs at the posterior rim of the foramen magnum, mainly recruited by the hypertrophic jugular branch of the APA originating from the occipital artery. The fistula was successfully treated surgically following transarterial embolization through the jugular branch of the APA using NBCA. Follow-up DSA confirmed complete obliteration of the DAVF. The patient has remained clinically asymptomatic 2 years after the operation.

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.