Management of distal aneurysm of the superior mesenteric artery by percutaneous ultrasound-guided Onyx injection: A case report.

OBJECTIVES: The aim of this article is to report an alternative approach for the management of a distal aneurysm of superior mesenteric artery using direct percutaneous ultrasound-guided Onyx injection. METHODS: We report a rare case of symptomatic superior mesenteric artery aneurysm. A 78-year-old man presents with pain and pulsating mass in the right umbilical region of the abdomen. The patient was treated by percutaneous ultrasound-guided Onyx injection after several failing transarterial embolization attempts. RESULTS: The procedure was successful without any complication, and the patient wasdischarged to home the day after procedure. Follow-up at 60 months confirmed the complete thrombosis of the aneurysm sac. Ultrasound-guided Onyx injection for distal superior mesenteric artery aneurysm could provide an alternative to transcatheter arterial embolization or open surgery. Anatomical assessment of collaterals and knowledge of abdomen anatomy could play important roles in preventing bowel ischemia and minimizing the risk of procedural complication. CONCLUSION: Ultrasound-guided Onyx injection of superior mesenteric artery aneurysm is a feasible, effective, and cost-saving technique that can be used when endovascular approach is not possible or has failed.

Long-term follow-up of transarterial balloon-assisted Onyx embolization for endovascular treatment of dural arteriovenous fistulas: A single-institution case series and literature review.

OBJECTIVE: Dural arteriovenous fistulas (DAVFs)-specifically, symptomatic DAVFs with cortical venous reflux-are aggressive lesions with a poor prognosis. Intra-arterial endovascular closure is considered the optional treatment for DAVFs and is currently performed at several international centers. However, long-term outcomes remain unknown. This study investigated the long-term efficacy and safety of transarterial balloon-assisted Onyx embolization in the treatment of DAVFs. METHODS: A total of 14 consecutive patients who underwent endovascular treatment for DAVFs were treated by balloon-assisted Onyx embolization. Additionally, we retrospectively reviewed all cases reported in the literature and compared the outcomes of patients treated with single- vs dual-lumen microcatheters. RESULTS: The patients at our institution were followed-up for 114.57 ± 33.52 months. Embolization was performed by balloon-assisted Onyx injection via a single feeding artery. Complete occlusion was achieved in 13 cases and partial occlusion in 1 case. At the final follow-up, all patients were functionally independent (Modified Rankin Scale score of 0-2), with no recurrence. In our review of 70 published cases of DAVFs that underwent endovascular treatment by balloon-assisted Onyx embolization, single- and dual-lumen balloon catheters were used in 33 and 37 patients, respectively. In the former group, there was complete or near-complete occlusion in 32 cases and partial occlusion in 1 case; and in the latter, there was complete or near-complete occlusion in 35 cases and partial occlusion in 2 cases. There were no deaths following endovascular treatment. CONCLUSION: Measurable and durable outcomes can be achieved by endovascular treatment of DAVFs with the transarterial balloon-assisted Onyx embolization technique, especially in cases with small, distal, and circuitous feeding arteries.

Transradial middle meningeal artery embolization for chronic subdural hematoma using Onyx: case series.

BACKGROUND: Middle meningeal artery (MMA) embolization is an emerging therapy for the resolution of subacute or chronic subdural hematoma (CSDH). CSDH patients are often elderly and have several comorbidities. We evaluated our experience with transradial access (TRA) for MMA embolization using predominantly Onyx under conscious sedation. METHODS: Data for consecutive patients who underwent transradial MMA embolization for CSDH during a 2-year period (2018-2019) were analyzed from a single-center, prospectively-maintained database. Patient demographics, comorbidities, ambulatory times, subdural hematoma resorption status, and guide catheter type were recorded. Conversion to femoral access and complication rates were also recorded. Univariate and multivariate analyses were performed. RESULTS: Forty-six patients (mean age, 71.7±14.4 years) were included in this study. Mean CSDH size was 14±5.5 mm. Most (91.3%) TRA embolizations were performed with 6-French 0.071-inch Benchmark guide catheters (Penumbra). MMA embolization was successful in 44 patients (95.7%) (including two cases of TRA conversion). Twenty-one (48%) patients had a severe Charlson Comorbidity Index (>5). Symptomatic improvement was noted in 39 of 44 patients (88.6%). Mean length of stay was 4±3 days. Patients were ambulated immediately postprocedure. At mean follow-up (8±4 weeks), 86.4% of patients had complete or partial CSDH resolution. Persistent use of antiplatelet agents after the procedure was associated with failed or minimal CSDH resorption (5 of 6, 83.3% vs 9 of 38 23.7% with complete or near-complete resolution; P=0.009). CONCLUSION: Transradial Onyx MMA embolization under conscious sedation is safe and effective for CSDH treatment. TRA may be especially useful in elderly patients with numerous comorbidities.

Update Onyx embolization for plexiform arteriovenous malformation: Ante-grade drifting technique.

OBJECTIVE: The conventional arteriovenous malformation (AVM) Onyx embolization technique is the extrusion Onyx injection technique, with blood-flow control after a certain distance casting through the head end of the microcatheter. This method has elevated periprocedural AVM bleeding complications. In this study, the authors reported safety and efficacy of an updated ante-grade drifting Onyx injection for plexiform AVM embolization. METHODS: Between January 2016 and December 2018, 101 consecutive patients with plexiform AVMs were treated with ante-grade drifting Onyx injection. The patients' clinical status was classified using the modified Rankin Scale (mRS). To measure associations, logistic univariate or multivariate regression analyses were used. RESULTS: Complete AVM obliteration was achieved in 51.2% (52/101) of patients. Two (2/101, 2.0%) arterial perforations occurred without causing neurological deficits. In univariate and multivariate logistic regression analyses, younger patient age (odds ratio (OR) = 1.06, 95% confidence interval (CI) 1.01-1.12, p = 0.014), haemorrhagic presentation at admission (OR = 7.14, 95% CI 1.52-33.33, p = 0.013) and low Spetzler-Martin grade (OR = 10.00, 95% CI 3.45-25.00, p < 0.001) were significantly correlated with complete obliteration. Pretreatment mRS was correlated with perforation complication (OR = 3.44, 95% CI 1.05-11.29, p = 0.041) in univariate logistic regression analysis but not in multivariate logistic regression analysis (OR = 2.956, 95%CI 0.745, 11.731, p = 0.123). Patients' clinical status was significantly improved after endovascular AVM embolization. CONCLUSIONS: With ante-grade drifting Onyx injection, it was possible to prevent serious bleeding complications and elevated complete embolization rate in plexiform AVMs. Younger patient age, haemorrhagic presentation at admission and low AVM Spetzler-Martin grade were significantly correlated with complete obliteration. Although there is not enough statistical power to show that the pretreatment mRS and the arterial perforation complication have a significant correlation, but its OR value is large, and there may be more data in the future to obtain further conclusion.

Pre-Surgical Endovascular Proximal Feeder Artery Devascularization Technique for the Treatment of Cranial Arteriovenous Malformations.

OBJECTIVE: Treatment of brain arteriovenous malformations (AVMs) aims to abolish any risk for intracranial hemorrhage with the preservation of the patient's functional status. We present the technique of pre-surgical endovascular devascularization through proximal feeder artery occlusion for the treatment of cranial AVMs rather than nidus occlusion. Also, we highlight the advantages and the possible clinical indications. PATIENTS AND METHODS: Two patients with brain AVM and one patient with scalp AVM were treated by pre-surgical endovascular devascularization followed by surgical resection. Endovascular devascularization was performed by occlusion of the AVM feeders only with Liquid Embolic System Agent (Onyx®) 18 without entering and filling the nidus. During surgery, feeding arteries colored with the black color of the Liquid Embolic System Agent were clearly identified and cut. Dissection of the AVM was performed, and resection of the nidus was achieved. RESULTS: Total resection of the AVM was achieved in all cases confirmed with follow-up angiographies, with no neurologic or systemic complications. Also, no major bleeding was detected. In addition, the surgical clips were avoided during surgery. Brain AVMs were safely resected in piecemeal fashion. CONCLUSION: Pre-surgical endovascular proximal feeder artery devascularization technique shows to be a safe, simple and effective technique for the management of cranial arteriovenous malformations. This technique simplifies both the endovascular and surgical approaches to complicated cranial AVM cases.

Outcomes of Onyx® Embolization of Type II Endoleaks After Endovascular Repair of Abdominal Aortic Aneurysms.

BACKGROUND: Type II endoleaks (T2ELs) are common following endovascular repair of abdominal aortic aneurysms (EVAR). Embolization with ethylene vinyl alcohol copolymer (Onyx) may present an effective treatment alternative for T2ELs. Due to limited data supporting its use, we sought to analyze outcomes of Onyx embolization for T2ELs. METHODS: Retrospective review of consecutive patients treated for T2ELs utilizing Onyx embolization agent from 2009-2018. All pre- and post-Onyx intervention CT scans were analyzed for diameter and volume changes with 3D reconstruction software. The primary outcomes were change in maximum AAA diameter and volume. Secondary outcomes included additional interventions, rupture, and mortality. A subset analysis was performed with patients with isolated T2ELs (no other types of endoleaks present). RESULTS: We identified 85 patients (73 males, mean age 77.6 ± 7.6 years) who underwent 112 Onyx interventions. Average time to first Onyx intervention after index EVAR was 3.3 ± 2.6 years and average sac growth was 6.3 ± 6.7 mm. Patients underwent mean 1.3 Onyx interventions using a mean of 4.9 ± 4.7 ml for treatment. Three complications occurred (Onyx extravasation, colon ischemia, and access site hematoma). Mean follow-up was 2.5 ± 2.1 years after initial Onyx treatment. At the most recent follow-up, sac diameter stabilization was seen in 47% and reduction >5 mm was seen in 19%. Sac growth of >5 mm was seen in 34% of patients following the first Onyx intervention. In our subset of isolated T2EL, 72% had sac stabilization or reduction >5 mm. Four patients experienced a ruptured aneurysm (3 had active type 1 endoleaks). Rupture-free survival was 95% at 5 years, and overall survival was 54% at 5 years. Notably, increasing Onyx interventions were not associated with sac stabilization or reduction (OR 0.6, P = 0.1). On multivariable analysis, AAA sac diameter stabilization or reduction was independently associated with BMI >30 kg/m2 (OR 4.2, P = 0.01) and having only 1 Onyx intervention (OR 3.8, P = 0.02). CONCLUSIONS: Onyx for embolization of T2ELs resulted in AAA sac diameter stabilization or reduction in 66% of patients, and up to 72% in isolated T2ELs. Further, increasing Onyx interventions were not associated with either aneurysm sac stabilization or reduction. Given its similar outcomes to other embolization strategies in the literature, Onyx embolization for management of T2ELs needs to be judiciously considered, particularly for T2ELs persisting after an initial Onyx embolization intervention.

Carotid-Cavernous Sinus Fistula caused by Persistent Primitive Trigeminal Artery Aneurysm rupture: A case report.

Carotid-Cavernous sinus fistula (CCF) caused by a ruptured aneurysm of persistent primitive trigeminal artery (PPTA) is exceptionally rare. Herein, we reported the case of a 64-year-old female who presented with headache, pulsatile tinnitus, and diplopia. Angiography showed a PPTA and CCF. Three-dimensional digital subtraction angiograms revealed a direct shunt between the PPTA aneurysm and the left cavernous sinus. The trigeminal carotid fistula was successfully treated with detachable coils and Onyx, and the PPTA was preserved. Hence, coil and Onyx occlusion of the cavernous sinus is a safe and effective treatment for trigeminal carotid fistula.

Monomelic Ischemic Neuropathy of the Tibial and Peroneal Nerve After Onyx Embolization of Vasa Nervorum Supplying a Surgically Excluded Popliteal Artery Aneurysm.

Ischemic neuropathy is an exceedingly rare complication after peripheral artery embolization. We report a case of ischemic damage to the tibial and peroneal nerve after embolization of the vasa nervorum that served as feeding collaterals to a surgically excluded popliteal artery aneurysm.

Dynamic airway constriction in rats: heterogeneity and response to deep inspiration.

Airway narrowing due to hyperresponsiveness severely limits gas exchange in patients with asthma. Imaging studies in humans and animals have shown that bronchoconstriction causes patchy patterns of ventilation defects throughout the lungs, and several computational models have predicted that these regions are due to constriction of smaller airways. However, these imaging approaches are often limited in their ability to capture dynamic changes in small airways, and the patterns of constriction are heterogeneous. To directly investigate regional variations in airway narrowing and the response to deep inspirations (DIs), we utilized tantalum dust and microfocal X-ray imaging of rat lungs to obtain dynamic images of airways in an intact animal model. Airway resistance was simultaneously measured using the flexiVent system. Custom-developed software was used to track changes in airway diameters up to generation 19 (~0.3-3 mm). Changes in diameter during bronchoconstriction were then measured in response to methacholine (MCh) challenge. In contrast with the model predictions, we observed significantly greater percent constriction in larger airways in response to MCh challenge. Although there was a dose-dependent increase in total respiratory resistance with MCh, the percent change in airway diameters was similar for increasing doses. A single DI following MCh caused a significant reduction in resistance but did not cause a significant increase in airway diameters. Multiple DIs did, however, cause significant increases in airway diameters. These measurements allowed us to directly quantify dynamic changes in airways during bronchoconstriction and demonstrated greater constriction in larger airways.

Recurrent Ectopic Variceal Bleed After Pancreas Transplantation With No Portal Hypertension: Case Report and Outcomes of Endovascular Onyx Embolization.

A 57-year-old male presented with intermittent gastrointestinal bleeding (GIB) 1 year after a successful simultaneous pancreas and kidney transplant. No source could be found after 5 tagged red blood cell studies, 3 computed tomographies (CTs), 7 endoscopies, and 4 catheter angiograms. Review of CTs showed pathologically enlarged superior mesenteric vein branches near a jejunal segment near pancreas graft. Transhepatic superior mesenteric venogram showed varicosities near jejunum, which were obliterated with ethylene vinyl alcohol (Onyx). Follow-up CTs confirmed complete obliteration, but he had more GIBs and eventually underwent native jejunal and donor duodenal resection. He has remained GIB-free for 12 months.

Onyx Embolization for Occlusion of the Proximal Internal Iliac Artery During EVAR in Patients with Unsuitable Landing Zones in the Common Iliac Artery.

BACKGROUND: Twenty percent of the patients with AAA have an aneurysm involving the common iliac arteries. Large common iliac diameter can be treated with an iliac branched device or extension of the stent graft to the external iliac artery with occlusion of the ipsilateral internal iliac artery (IIA) to prevent type 2 endoleaks. This study describes and evaluates a embolization technique using Onyx in conjunction with EVAR in aneurysms with poor landing zones in the common iliac arteries. METHODS: Patients with Onyx IIA embolization during EVAR, identified from the hospital operating code database, constitute the study population. Onyx embolization was performed by injection at the IIA origin. Peri- and postoperative complications were collected from the medical records. Thin-sliced CT scan was performed 1 month and 1 year after the procedure. RESULTS: Thirty-six patients with complex iliac anatomy and insufficient landing zones (without sealing possibility for standard stent grafts) were identified out of 243 consecutive EVAR treatments during a 13-year period. In seventeen patients (7%), the IIA was embolized with Onyx. Technical success was obtained in all 17 patients, without adverse event or procedural complication. No complication related to the embolization procedure was noted during follow-up. CONCLUSIONS: During EVAR treatment of patients with aneurysm involving the common iliac artery, Onyx embolization of IIA is a feasible option without need of selective catheterization of the IIA orifice, potentially preserving important branches of the IIA and simplifying emergency procedures.

Embolization of brain arteriovenous malformations with the diluted Onyx technique: initial experience.

PURPOSE: Insufficient nidus occlusion is a matter of great concern to routine Onyx embolization of brain arteriovenous malformations (AVMs). This paper described an efficient method which using the diluted Onyx embolization technique to treat brain AVM. METHODS: The diluted Onyx technique was performed in a series of 15 patients with brain AVMs (10 males, 5 females; age range, 11-44 years). It consists of initial embolization with routine Onyx-18, followed by the diluted Onyx (1.5 mL of Onyx-18 diluted with 0.5 mL of DMSO) through the same microcatheter. The technical skills and angiographic and clinical outcomes were analyzed. RESULTS: A total of 15 embolization sessions were performed with diluted Onyx via 16 arterial feeders in these 15 patients. Each patient underwent one attempt of diluted Onyx through a single feeder except one patient. In this patient, the AVM was simultaneously embolized with diluted Onyx through double microcatheters which were placed in two feeders. When the length of reflux reached to 2 cm (or close to the determined length) and the embolic material could not move distally any more despite some rounds of "injection-reflux-waiting," regular Onyx 18 was changed to diluted Onyx. Antegrade flow of embolic material into the nidus was observed in 12 cases but failed in 3. An average of 90% (range 55-100%) estimated size reduction was achieved, and 6 AVMs were completely obliterated. No functionally relevant complications occurred. CONCLUSION: The diluted Onyx technique could be a useful adjunct to routine Onyx embolization which may offer more embolic material penetrating into the nidus of AVM, but additional work is needed to validate this technique.

Separating High-Z Oral Contrast From Intravascular Iodine Contrast in an Animal Model Using Dual-Layer Spectral CT.

RATIONALE AND OBJECTIVES: To show that water and iodine two-material decomposition images from dual-layer dual-energy spectral X-ray computed tomography (DECT) can be used to separate intravascular iodine contrast from simultaneously administered oral tantalum, tungsten, or rhenium contrast in an animal model. MATERIALS AND METHODS: In this Institutional Animal Care and Use Committee approved study, four female Fischer rats were given simultaneous intravenous and oral X-ray computed tomography contrast. Intravenous iodine contrast was administered via tail vein injection. Oral barium, tantalum, tungsten, or rhenium contrast was administered via gavage. The animals were imaged on a dual-layer DECT system at 120 kVp. Water and iodine two-material decomposition images (water equivalent and iodine equivalent images) were used for qualitative analysis. Computer simulations were performed using a customized DECT simulator to better understand why certain high-Z elements disappear in the iodine equivalent images and what is the theoretical range of elements with this property. RESULTS: The iodine and barium contrast appeared only in the iodine equivalent images and could not be differentiated from each other. However, the tantalum, tungsten, and rhenium contrast only appeared in the water equivalent images. This allowed iodine contrast in the bowel wall to be easily segmented from tantalum, tungsten, and rhenium contrast in the bowel lumen. Simulations confirmed that certain high-Z elements will have pixel values of ≤0 mg iodine/mL in the iodine equivalent images due to a K-edge effect associated with DECT systems. CONCLUSIONS: Dual-layer DECT can separate iodine from certain high-Z elements using water equivalent and iodine equivalent images with an increased element range compared to other DECT systems. This K-edge effect could promote the development and approval of new high-Z contrast agents for DECT.

Vagal Nerve Palsy After Transarterial Embolization of Transverse-Sigmoid Dural Arteriovenous Fistula Using Onyx.

OBJECTIVE: We report a case of a 70-year-old man who developed a transverse-sigmoid dural arteriovenous fistula (TS-DAVF) that was successfully treated by transarterial embolization (TAE) with Onyx. CASE PRESENTATION: The patient presented with sudden and progressive disturbance of consciousness and left hemiparesis. Magnetic resonance imaging (MRI) revealed venous infarction and hemorrhagic changes with brain swelling in the right parietal lobe. Angiography revealed a right TS-DAVF and multiple occlusions with retrograde leptomeningeal venous drainage into the cortical veins. The TS-DAVF was graded as Borden type III and Cognard type IIa+b. Because of its progressive clinical nature and wide distribution of DAVF in the occluded sinus wall, he underwent emergent TAE with liquid embolic materials including n-butyl cyanoacrylate and Onyx under informed consent by his family. Complete obliteration of the TS-DAVF was achieved, leading to a marked amelioration of symptoms, and MRI after treatment confirmed a decrease in the brain swelling. However, he suffered transient dysphagia due to right vagal nerve palsy caused by occlusion of vasa nervorum of ascending pharyngeal artery. He returned home 5 months later with a modified Rankin Scale of 1. CONCLUSIONS: TAE with Onyx appears to be effective for aggressive TS-DAVF with a widely distributed shunt. However, the blood supply to the cranial nerves and potentially dangerous anastomoses between the external-internal carotid artery and vertebral artery should be taken into account to avoid serious complications.

An Intravascular Tantalum Oxide-based CT Contrast Agent: Preclinical Evaluation Emulating Overweight and Obese Patient Size.

Purpose To compare the CT imaging performance of a carboxybetaine zwitterionic-coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated contrast agent in a swine model meant to simulate overweight and obese patients. Materials and Methods Four swine were evaluated inside three different-sized adipose-equivalent encasements emulating abdominal girths of 102, 119, and 137 cm. Imaging was performed with a 64-detector row CT scanner at six scan delays after intravenous injection of 240 mg element (Ta or I) per kilogram of body weight of TaCZ or iopromide. For each time point, contrast enhancement of the aorta and liver were measured by using regions of interest. Two readers independently recorded the clarity of vasculature using a five-point Likert scale. Findings were compared by using paired t tests and Wilcoxon signed-rank tests. Results Mean peak enhancement was higher for TaCZ than for iopromide in the aorta (270 HU [σ = 24.5] vs 199 HU [σ = 10.2], P < .001) and liver (61.3 HU [σ = 11.7] vs 45.2 HU [σ = 8], P < .001). Vascular clarity was higher for TaCZ than for iopromide in 63% (132 of 208), 82% (170 of 208), and 86% (178 of 208) of the individual vessels at the 102-, 119-, and 137-cm girths, respectively (P < .01). Arterial clarity scores were higher for TaCZ than for iopromide in 62% (208 of 336) of vessels. Venous clarity scores were higher for TaCZ than for iopromide in 89% (128 of 144) of the veins in the venous phase and in 100% (144 of 144) of veins in the delayed phase (P < .01). No vessel showed higher clarity score with iopromide than with TaCZ. Conclusion An experimental tantalum nanoparticle-based contrast agent showed greater contrast enhancement compared with iopromide in swine models meant to simulate overweight and obese patients. © RSNA, 2018.

What is the rate of patients undergoing a total hip arthroplasty after core decompression and insertion of a tantalum rod in osteonecrosis of the femoral head: a systematic review.

PURPOSE: Core decompression (CD) may be effective when performed during the early stages of osteonecrosis of the femoral head (ONFH). Tantalum may be added as a rod that would allow putting some mechanical constraints on the femoral head. We aimed to estimate the rate of total hip arthroplasty after CD and insertion of a tantalum rod during early stages of OFNH. METHODS: We searched systematically Medline via PubMed and the Cochrane Library. Our primary endpoint was the rate of patients undergoing a total hip arthroplasty after CD and insertion of a tantalum rod. Secondary endpoints were the delay between the initial surgery and the arthroplasty, the functional improvement, and the rate of complications. RESULTS: We included seven  studies reporting the results of 232 patients (297 hips) that were operated on by CD and insertion of a tantalum rod. At a mean follow-up of 26.97 months, 24.63% of the included hips underwent a hip arthroplasty (6-56%, SD = 17.34%). The mean delay between the initial surgery and the arthroplasty was 14.94 months (10.20-22.90; SD = 5.25), the mean improvement of Harris Hip Score was 27.66 (20.20-36.90; SD = 6.48), and the mean rate of femoral fracture was 2.43% (0-13%, SD = 4.89%). CONCLUSION: CD and insertion of a tantalum rod may represent a solution in order to improve the mechanical support and to give a rate of conversion in arthroplasty that is acceptable.

Curative Transvenous Embolization for Ruptured Brain Arteriovenous Malformations: A Single-Center Experience from China.

OBJECTIVE: To evaluate feasibility and safety of transvenous embolization for brain arteriovenous malformations (AVMs). METHODS: Between November 2016 and August 2017, a transvenous endovascular embolization protocol was implemented at the Henan Provincial People's Hospital for consecutive patients with ruptured brain AVMs. Therapeutic decision making was based on Spetzler-Martin grade, brain AVM location, pattern of venous drainage, and angioarchitecture. Transvenous embolization was combined with transarterial support. Complete angiographic obliteration of the nidus was the objective of treatment. RESULTS: Among 10 patients with ruptured brain AVMs, 8 were male. Spetzler-Martin grades before transvenous embolization were IV in 3 patients, III in 5 patients, II in 1 patient, and I in 1 patient. Modified Rankin Scale score before the procedure was 0-2 for 6 of 10 patients. Five patients also had deep venous drainage. Arterial blood pressure control and venous pressure cooker technique were used in all 10 patients; 9 patients had immediate angiographic occlusion. Two patients had a ventricular hemorrhage, which did not cause any disability after medical treatment. Seven patients underwent angiography 3-5 months after the procedure, and complete obliteration of the nidus was confirmed. Median clinical follow-up for all 10 patients was 8 months (range, 3-12 months). Epilepsy occurred in 1 patient 3 months after the procedure, and modified Rankin Scale scores for all patients were ≤1. CONCLUSIONS: Transvenous embolization of brain AVMs is feasible and may improve cure rates. The safety and long-term effects need further validation.