Transarterial Embolization of Renal Arteriovenous Malformations: Treatment Outcomes According to Angiographic Classification.

PURPOSE: To assess the different adjunctive catheter techniques required to achieve complete occlusion of renal arteriovenous malformations (rAVMs) of different angioarchitectural types. MATERIALS AND METHODS: Overall, data on 18 patients with rAVM (Type 1, n = 7; Type 2, n = 2; Type 3, n = 9; mean age, 53.8 years) who underwent 25 procedures between 2011 and 2022 were reviewed. The clinical presentations, endovascular techniques, arteriovenous malformation (AVM) occlusion rate, adverse events (including the incidence of renal infarction), and clinical symptoms and outcomes (including recurrence/increase of AVM) were analyzed according to the Cho-Do angioarchitectural classification. Posttreatment renal infarction was classified as no infarction, small infarction (<12.5%), medium infarction (12.5%-25%), and large infarction (>25%) using contrast-enhanced computed tomography or magnetic resonance imaging. RESULTS: Hematuria and heart failure were presenting symptoms in 10 and 2 patients, respectively. The embolic materials used were as follows: Type 1 rAVM, coils alone or with n-butyl-2-cyanoacrylate (nBCA); Type 2 rAVM, nBCA alone or with coils; and Type 3 rAVMs, nBCA alone. Fourteen patients underwent adjunctive catheter techniques, including flow control with a balloon catheter and multiple microcatheter placement, alone or in combination. Immediate postprocedural angiography revealed complete occlusion in 15 patients (83%) and marked regression of rAVM in 3 (17%). Small asymptomatic renal infarctions were observed in 6 patients with Type 3 rAVMs without any decrease in renal function. No major adverse events were observed. All symptomatic patients experienced symptom resolution. Recurrence/increase of rAVM was not observed during the mean 32-month follow-up period (range, 2-120 months). CONCLUSIONS: Transarterial embolization using adjunctive catheter techniques according to angioarchitectural types can be an effective treatment for rAVMs.

[Brain Arteriovenous Malformations:Indications and Treatment Results of Endovascular Embolization].

Brain arteriovenous malformations(BAVMs)are rare, but have a risk of serious intracranial hemorrhage in young adults. Endovascular treatment(EVT)has an important role in BAVM management with various purposes, including preoperative devascularization, volume reduction before stereotactic radiotherapy, curative embolization, and palliative embolization. In this article, the author reviews recent studies on EVT and relevant studies on BAVM management. Although no definitive evidences of utilizing EVT have been provided because of the various EVT outcomes depending upon various angioarchitectures, treatment goals, strategies, and physician's skills, EVT is certainly useful in selected cases. The role of EVT in BAVM management should be tailored to each patient while weighing the relative risks and benefits.

Location of embolization affects patency after coil embolization for pulmonary arteriovenous malformations: importance of time-resolved magnetic resonance angiography for diagnosis of patency.

OBJECTIVES: This study aimed to assess the diagnostic accuracy of computed tomography (CT) and time-resolved magnetic resonance angiography (TR-MRA) for patency after coil embolization of pulmonary arteriovenous malformations (PAVMs) and identify factors affecting patency. METHODS: Data from the records of 205 patients with 378 untreated PAVMs were retrospectively analyzed. Differences in proportional reduction of the sac or draining vein on CT between occluded and patent PAVMs were examined, and receiver operating characteristic analysis was performed to assess the accuracy of CT using digital subtraction angiography (DSA) as the definitive diagnostic modality. The accuracy of TR-MRA was also assessed in comparison to DSA. Potential factors affecting patency, including sex, age, number of PAVMs, location of PAVMs, type of PAVM, and location of embolization, were evaluated. RESULTS: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT were 82%, 81%, 77%, 85%, and 82%, respectively, when the reduction rate threshold was set to 55%, which led to the highest diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and accuracy of TR-MRA were 89%, 95%, 89%, 95%, and 93%, respectively. On both univariable and multivariable analyses, embolization of the distal position to the last normal branch of the pulmonary artery was a factor that significantly affected the prevention of patency. CONCLUSIONS: TR-MRA appears to be an appropriate method for follow-up examinations due to its high accuracy for the diagnosis of patency after coil embolization of PAVMs. The location of embolization is a factor affecting patency. KEY POINTS: • Diagnosis of patency after coil embolization for pulmonary arteriovenous malformations (PAVMs) is important because a patent PAVM can lead to neurologic complications. • The diagnostic accuracies of CT with a cutoff value of 55% and TR-MRA were 82% and 93%, respectively. • The positioning of the coils relative to the sac and the last normal branch of the artery was significant for preventing PAVM patency.

Vessel Occlusion using Hydrogel-Coated versus Nonhydrogel Embolization Coils in Peripheral Arterial Applications: A Prospective, Multicenter, Randomized Trial.

PURPOSE: To evaluate the safety and effectiveness of hydrogel-coated coils for vessel occlusion in the body trunk. MATERIALS AND METHODS: A total of 77 patients with various peripheral vascular lesions, treatable by embolization with coils, were randomized (hydrogel group, n = 38; nonhydrogel group, n = 39). In the hydrogel group, embolization of the target vessel was conducted using 0.018-inch hydrogel-coated coils (AZUR 18; Terumo Medical Corporation, Tokyo, Japan) with or without bare platinum coils. The nonhydrogel group received both bare platinum coils and fibered coils without the use of hydrogel-coated coils. RESULTS: Complete target vessel occlusion was accomplished in 36 patients in the hydrogel group and 37 patients in the nonhydrogel group. No major adverse events were observed in either group. The median number of coils/vessel diameter and the median total coil length/vessel diameter were significantly larger in the nonhydrogel group than in the hydrogel group (P = .005 and P = .004, respectively). The median embolization length was significantly longer in the nonhydrogel group (31.95 mm) than in the hydrogel group (23.43 mm) (P = .002). If no expansion was assumed, the median packing density in the hydrogel group was 44.9%, which was similar to that in the nonhydrogel group (46.5%) (P = .79). With full expansion assumed, the median packing density in the hydrogel group was 125.7%. CONCLUSIONS: Hydrogel-coated coils can be safely used for peripheral vascular coil embolization, and hydrogel-coated and conventional coils in combination allow for a shorter embolization segment and shorter coil length.

Delineability and anatomical variations of perforating arteries from normal vertebral artery on 3D DSA: implications for endovascular treatment of dissecting aneurysms.

BACKGROUND AND PURPOSE: Endovascular trapping of the vertebral artery dissecting aneurysms (VADAs) carries a risk of medullary infarction due to the occlusion of the perforating arteries. We evaluated the detectability and anatomical variations of perforating arteries arising from the vertebral artery (VA) using three-dimensional DSA. METHODS: In 120 patients without VA lesions who underwent rotational vertebral arteriography, the anatomical configurations of perforating arteries from the VA were retrospectively evaluated on the bi-plane DSA and reconstructed images to reach the consensus between two experienced reviewers. The images were interpreted by focusing on the numbers and types of perforating arteries, the relationships between the number of perforators and the anatomy of the VA and its branches. RESULTS: Zero, 1, 2, 3, 4, and 6 perforators were detected in 2, 51, 56, 9, 1, and 1 patient, respectively (median of 2 perforators per VA). The 200 perforators were classified into 146 terminal and 54 longitudinal course types and into 32 ventral, 151 lateral, and 17 dorsolateral distribution types. All ventral type perforators were also terminal type. In contrast, the longitudinal type was seen in 28.5% of lateral types and in 65% of dorsolateral types. Regarding the difference in the origin of the posterior inferior cerebellar artery (PICA), non-PICA type VAs gave off larger number of perforators than the other types of VAs. CONCLUSIONS: Non-PICA type VAs give off a significantly larger number of perforators than other types, indicating that the trapping of non-PICA type VAs is associated with a risk of ischemic complications.

Risk factors for medullary infarction after endovascular trapping of vertebral artery dissecting aneurysms.

Internal trapping (IT) is a treatment option for intracranial vertebral artery dissecting aneurysms (VADAs). Medullary infarction (MI) is a complication linked to this treatment. This study aims to clarify the outcomes of IT for VADAs and the risk factors for MIs. We retrospectively reviewed the databases from 2010 to 2017 to identify patients with VADAs treated by IT at seven collaborating institutions. Radiological findings, clinical courses, and outcomes were analyzed. Perforating arteries were classified into terminal or longitudinal types using preoperative angiography. IT was completed in 90 patients (74 ruptured and 16 unruptured VADA). Postoperative rebleeding did not occur in any ruptured VADA patients. Postoperative MRI detected MIs in 26 patients (28.9%). The incidence of MIs in the ruptured VADA (32%) was higher compared with that in the unruptured VADA (13%), though it was not significant. In the MI group, the occlusion or blind alley of the terminal-type and longitudinal-type perforator was confirmed in 23 patients (88%) and 11 patients (42%), respectively. The occlusion or blind alley of the terminal-type perforator was an independent risk factor for MIs in the logistic regression analysis (OR 5.81; 95% CI 1.34-25.11; p = 0.018). In ruptured VADA, postoperative MI (OR 12.2; 95% CI 3.19-64.55; p = 0.0001) and high-grade SAH (OR 8.02; 95% CI 2.32-37.70; p = 0.0006) were independent risk factors of an unfavorable clinical outcome. In conclusion, MIs were an independent risk factor for unfavorable outcomes after IT, especially for a ruptured VADA. The occlusion or blind alley of the terminal-type perforator caused by the IT was associated with postoperative MIs.

[Dural Arteriovenous Fistula].

Dural arteriovenous fistulas(dAVFs), which are arteriovenous shunts between the dural/epidural artery and dural vein and/or dural venous sinus, can cause various symptoms, and the risk of aggressive symptoms such as cerebral hemorrhage and venous infarction mainly depends on venous drainage patterns in patients. Patients with dAVFs with cortical venous reflux have a high risk of aggressive symptoms due to cerebral venous congestion or varix rupture, and they often develop brain edema and/or hemorrhage. In some cases, patients with dAVFs may have CT and MRI findings similar to those of patients with brain tumors. Key MRI findings suggesting dAVFs include multiple small flow voids representing cortical venous reflux adjacent to the hemorrhage or edematous lesion on T2WI and dot-like high-signal-intensity patterns of the feeding arteries and draining veins on time-of-flight MR angiography source images. Cerebral angiography should be performed quickly when dAVFs are suspected with careful assessment using CT/MRI to prevent further worsening of symptoms, particularly for lesions involving the brain stem and cerebellum.

Angiographic and Clinical Characteristics of Thoracolumbar Spinal Epidural and Dural Arteriovenous Fistulas.

BACKGROUND AND PURPOSE: The purpose of this study is to compare the angiographic and clinical characteristics of spinal epidural arteriovenous fistulas (SEAVFs) and spinal dural arteriovenous fistulas (SDAVFs) of the thoracolumbar spine. METHODS: A total of 168 cases diagnosed as spinal dural or extradural arteriovenous fistulas of the thoracolumbar spine were collected from 31 centers. Angiography and clinical findings, including symptoms, sex, and history of spinal surgery/trauma, were retrospectively reviewed. Angiographic images were evaluated, with a special interest in spinal levels, feeders, shunt points, a shunted epidural pouch and its location, and drainage pattern, by 6 readers to reach a consensus. RESULTS: The consensus diagnoses by the 6 readers were SDAVFs in 108 cases, SEAVFs in 59 cases, and paravertebral arteriovenous fistulas in 1 case. Twenty-nine of 59 cases (49%) of SEAVFs were incorrectly diagnosed as SDAVFs at the individual centers. The thoracic spine was involved in SDAVFs (87%) more often than SEAVFs (17%). Both types of arteriovenous fistulas were predominant in men (82% and 73%) and frequently showed progressive myelopathy (97% and 92%). A history of spinal injury/surgery was more frequently found in SEAVFs (36%) than in SDAVFs (12%; P=0.001). The shunt points of SDAVFs were medial to the medial interpedicle line in 77%, suggesting that SDAVFs commonly shunt to the bridging vein. All SEAVFs formed an epidural shunted pouch, which was frequently located in the ventral epidural space (88%) and drained into the perimedullary vein (75%), the paravertebral veins (10%), or both (15%). CONCLUSIONS: SDAVFs and SEAVFs showed similar symptoms and male predominance. SDAVFs frequently involve the thoracic spine and shunt into the bridging vein. SEAVFs frequently involve the lumbar spine and form a shunted pouch in the ventral epidural space draining into the perimedullary vein.

Balloon-Occluded Retrograde Transvenous Obliteration for Isolated Gastric Varices Draining through Pericardiophrenic Vein without Gastrorenal or Gastrocaval Shunts.

Balloon-occluded retrograde transvenous obliteration (BRTO) is an effective and minimally invasive treatment for isolated gastric varices (GVs) that is usually performed through a gastrorenal shunt (GRS) or gastrocaval shunt (GCS). However, there are some cases in which GVs drain mainly into the left pericardiophrenic vein without an accessible GRS or GCS. This brief report presents four cases of GVs without a GRS/GCS treated by BRTO through the pericardiophrenic vein. BRTO was successfully performed with the use of flexible balloon catheters without any complications in all four patients, and the GVs were completely obliterated.

Renal Arteriovenous Shunts: Clinical Features, Imaging Appearance, and Transcatheter Embolization Based on Angioarchitecture.

Renal arteriovenous (AV) shunt, a rare pathologic condition, is divided into two categories, traumatic and nontraumatic, and can cause massive hematuria, retroperitoneal hemorrhage, pain, and high-output heart failure. Although transcatheter embolization is a less-invasive and effective treatment option, it has a potential risk of complications, including renal infarction and pulmonary embolism, and a potential risk of recanalization. The successful embolization of renal AV shunt requires a complete occlusion of the shunted vessel while preventing the migration of embolic materials and preserving normal renal arterial branches, which depends on the selection of adequate techniques and embolic materials for individual cases, based on the etiology and imaging angioarchitecture of the renal AV shunts. A classification of AV malformations in the extremities and body trunk could precisely correspond with the angioarchitecture of the nontraumatic renal AV shunts. The selection of techniques and choice of adequate embolic materials such as coils, vascular plugs, and liquid materials are determined on the basis of cause (eg, traumatic vs nontraumatic), the classification, and some other aspects of the angioarchitecture of renal AV shunts, including the flow and size of the fistulas, multiplicity of the feeders, and endovascular accessibility to the target lesions. Computed tomographic angiography and selective digital subtraction angiography can provide precise information about the angioarchitecture of renal AV shunts before treatment. Color Doppler ultrasonography and time-resolved three-dimensional contrast-enhanced magnetic resonance angiography represent useful tools for screening and follow-up examinations of renal AV shunts after embolization. In this article, the classifications, imaging features, and an endovascular treatment strategy based on the angioarchitecture of renal AV shunts are described.

Shunted pouches of cavernous sinus dural AVFs: evaluation by 3D rotational angiography.

INTRODUCTION: The aims of this study were to evaluate the angioarchitecture of cavernous sinus dural arteriovenous fistulas (CSdAVFs), including the number and location of shunted pouches (SPs), and to evaluate whether the location and number of the SPs affect the outcomes of transvenous embolization of CSdAVFs. METHODS: Nineteen consecutive cases of CSdAVFs that underwent rotational angiography and transvenous embolization were reviewed. Multiplanar reconstruction images of rotational angiography and selective angiography were reviewed with particular interest in the SPs. Relationships of the locations and number of SPs with the results of transvenous embolization were statistically analyzed. RESULTS: All cases showed SPs, with numbers ranging from 1 to 4 (mean, 2.2). The location of the SPs was "posteromedial" in 16, "posterolateral" in 13, "lateral" in 6, and "medial" in 3 patients. Six cases showed posteromedial SPs alone, and three cases showed posterolateral SPs alone. The other 10 cases showed multiple locations of SPs. All cases were treated by transvenous embolization with sinus packing (n = 11) or selective embolization of the SP (n = 8). Complete occlusion of dAVF was obtained in 16 cases immediately after embolization. Locations of SPs and drainage types were significantly associated with the immediate angiographic results (p < 0.01). CONCLUSION: The SP of CSdAVFs is often multiple and is located posteriorly to the CS. The number and location of SPs affect immediate angiographic results of transvenous embolization.

Double coaxial microcatheter technique for transarterial aneurysm sac embolization of type II endoleaks after endovascular abdominal aortic repair.

PURPOSE: To evaluate the feasibility and efficacy of transarterial sac embolization with a mixture of N-butyl cyanoacrylate and ethiodized oil (Lipiodol; Guerbet Japan, Tokyo, Japan) (NBCA-LPD) for type II endoleaks after endovascular aortic repair (EVAR) using a double coaxial microcatheter technique. MATERIALS AND METHODS: A retrospective review was performed of 20 consecutive cases of type II endoleaks treated by transarterial embolization using the technique from August 2010 to June 2013. The treatment indication was persistent type II endoleak over 6 months after EVAR associated with aneurysm expansion ≥ 5 mm in maximum diameter. A 1.9-F nontapered microcatheter was advanced to the aneurysmal sac through a 2.7-F microcatheter, which was coaxially introduced through a catheter. The endpoint of the procedure was intrasaccular filling with NBCA-LPD and occlusion of the feeder of the type II endoleak. The technical success rate was defined as success in transarterial intrasaccular approach followed by embolization of the intrasaccular channel and inflow arteries. Clinical success was defined as aneurysmal sac shrinkage or stabilization (freedom from sac expansion > 5 mm in maximum diameter). RESULTS: Technical success was achieved in 18 of 20 cases. During a mean follow-up period of 18.5 months, complete sac occlusion was observed in 13 cases (65%). Clinical success was achieved in 16 cases (80%). No serious complications were observed. CONCLUSIONS: The transarterial intrasaccular approach with a double coaxial microcatheter technique can be successfully performed in most cases, and transarterial aneurysm sac embolization using NBCA-LPD has been proven to be feasible.

Anatomical variations in termination of the uncal vein and its clinical implications in cavernous sinus dural arteriovenous fistulas.

INTRODUCTION: The aim of the study was to investigate the variations in the uncal vein (UV) termination and its clinical implication in cavernous sinus dural arteriovenous fistulas (CSDAVFs). METHODS: Biplane cerebral angiography in 80 patients (160 sides) with normal cerebral venous return (normal group) was reviewed with special interest in the termination of the UV. Frequency and types of uncal venous drainage from CSDAVFs in consecutive 26 patients were also analyzed. RESULTS: In the normal group, the UV was identified in 118 sides (74 %). The UV terminated into cavernous sinus (CS) in 41 sides (34 %), the superficial middle cerebral vein (SMCV) in 58 sides (48 %), the laterocavernous sinus (LCS) in 15 sides (13 %), and the paracavernous sinus (PCS) in 4 sides (3 %). Cerebral venous blood via the UV draining into the CS directly (n=41) or through the SMCV and/or the LCS (n=45) was observed in 86 sides (54 %). Uncal venous drainage from CSDAVFs was found in 13 patients (50 %). The CSDAVFs drained directly into the UV in two patients, drained via LCS into the UV in two patients, and drained through the SMCV into the UV in the remaining nine patients. All cases were successfully treated by transvenous embolization with special attention given to uncal venous drainage. CONCLUSION: There are several variations in UV termination according to the embryological development of the primitive tentorial sinus and the deep telencephalic vein. Careful attention should be paid to uncal venous drainage for the treatment of CSDAVFs.

Detailed Anatomy of Bridging Veins Around the Foramen Magnum: a Multicenter Study Using Three-dimensional Angiography.

BACKGROUND AND PURPOSE: There has been limited literature regarding the bridging veins (BVs) of the medulla oblongata around the foramen magnum (FM). The present study aims to analyze the normal angioarchitecture of the BVs around the FM using slab MIP images of three-dimensional (3D) angiography. METHODS: We collected 3D angiography data of posterior fossa veins and analyzed the BVs around the FM using slab MIP images. We analyzed the course, outlet, and number of BVs around the FM. We also examined the detection rate and mean diameter of each BV. RESULTS: Of 57 patients, 55 patients (96%) had any BV. The median number of BVs was two (range: 0-5). The BVs originate from the perimedullary veins and run anterolaterally to join the anterior condylar vein (ACV), inferior petrosal sinus, sigmoid sinus, or jugular bulb, inferolaterally to join the suboccipital cavernous sinus (SCS), laterally or posterolaterally to join the marginal sinus (MS), and posteriorly to join the MS or occipital sinus. We classified BVs into five subtypes according to the draining location: ACV, jugular foramen (JF), MS, SCS, and cerebellomedullary cistern (CMC). ACV, JF, MS, SCS, and CMC BVs were detected in 11 (19%), 18 (32%), 32 (56%), 20 (35%), and 16 (28%) patients, respectively. The mean diameter of the BVs other than CMC was 0.6 mm, and that of CMC BV was 0.8 mm. CONCLUSION: Using venous data from 3D angiography, we detected FM BVs in most cases, and the BVs were connected in various directions.

Unenhanced magnetic resonance angiography with time-spatial labeling inversion pulse for evaluating visceral artery aneurysms after endosaccular packing with detachable coils: preliminary results.

The aim of this brief report is to compare unenhanced magnetic resonance (MR) angiography with time-spatial labeling inversion pulse (Time-SLIP) with conventional digital subtraction angiography (DSA) in assessing degree of saccular visceral artery aneurysm (VAA) occlusion after endosaccular packing with detachable coils. Eight patients with VAAs (five renal and three splenic artery aneurysms) were enrolled in this study. VAA occlusion rates based on Time-SLIP MR angiography were complete occlusion in four patients, neck remnants in three patients, and body filling in one patient. These findings corresponded with the DSA findings.

Multidetector CT anatomy of drainage routes of gastric varices: a pictorial review.

Most gastric varices arise at hepatofugal collateral pathways and drain into the systemic vein through one or both of two different types of portosystemic collateral drainage systems: the gastroesophageal (azygous) venous system and the gastrophrenic venous system. The gastroesophageal venous system consists of gastric varices contiguous with esophageal varices, paraesophageal varices, and the azygos vein, which terminates into the superior vena cava. Gastric varices draining through the gastroesophageal venous system can be treated with endoscopic techniques or creation of a transjugular intrahepatic portosystemic shunt. The gastrophrenic venous system consists of the gastric varices and the left inferior phrenic vein (IPV), which terminates into the left renal vein or the inferior vena cava. The left IPV has abundant anastomoses with peridiaphragmatic and retroperitoneal veins, and these anastomoses can function as drainage pathways from gastric varices. Balloon-occluded retrograde transvenous obliteration is a preferred treatment option for this type of gastric varix. Occasionally, gastric varices can form at the hepatopetal collateral pathway that develops secondary to localized portal hypertension caused by splenic vein occlusion. Splenectomy is often required for the treatment of this type of gastric varix. Multidetector computed tomography permits comprehensive evaluation of these venous drainage systems. Familiarity with and assessment of these draining routes of gastric varices are important for selecting treatment options and interventional techniques.

Maxillary artery: functional and imaging anatomy for safe and effective transcatheter treatment.

The maxillary artery is a terminal branch of the external carotid artery. Although the main maxillary artery trunk and most of its branches course within the extracranial space and supply the organs and muscles of the head and neck, other surrounding soft tissues, and the oral and rhinosinusal cavities, other branches supply the dura mater and cranial nerve and can anastomose to the internal carotid artery (ICA). Various pathologic conditions of the intracranial, head, and neck regions can involve the branches of the maxillary artery. Many of these diseases can be treated with endovascular approaches; however, there is a potential risk of complications in the brain parenchyma and cranial nerves related to the meningoneuronal arterial supply and anastomoses to the ICA. Therefore, familiarity with the functional and imaging anatomy of the maxillary artery is essential. In the past, conventional angiography has been the standard imaging technique for depicting the maxillary artery anatomy and related pathologic findings. However, recent advances in computed tomographic, magnetic resonance, and rotational angiography have further elucidated the maxillary artery anatomy by means of three-dimensional representations. Understanding the functional and imaging anatomy of the maxillary artery allows safe and successful transcatheter treatment of pathologic conditions in the maxillary artery territories.

Spinal ventral epidural arteriovenous fistulas of the lumbar spine: angioarchitecture and endovascular treatment.

INTRODUCTION: Spinal ventral epidural arteriovenous fistulas (EDAVFs) are relatively rare spinal vascular lesions. We investigated the angioarchitecture of spinal ventral EDAVFs and show the results of endovascular treatment. METHODS: We reviewed six consecutive patients (four males and two females; mean age, 67.3 years) with spinal ventral EDAVFs treated at our institutions from May 2011 to October 2012. All patients presented with progressive myelopathy. The findings of angiography, including 3D/2D reformatted images, treatments, and outcomes, were investigated. A literature review focused on the angioarchitecture and treatment of spinal ventral EDAVFs is also presented. RESULTS: The EDAVFs were located in the ventral epidural space at the L1-L5 levels. All EDAVFs were supplied by the dorsal somatic branches from multiple segmental arteries. The ventral somatic branches and the radiculomeningeal arteries also supplied the AVFs in two patients. The AVFs drained via an epidural venous pouch into the perimedullary vein in four patients and into both the perimedullary vein and paravertebral veins in two patients. Four cases without paravertebral drainage were treated by transarterial embolization with diluted glue, and two cases with perimedullary and paravertebral drainages were treated by transvenous embolization alone or in combination with transarterial embolization. An angiographic cure was obtained in all patients. Clinical symptoms resolved in two patients, markedly improved in three patients, and minimally improved in one patient. CONCLUSION: In our limited experience, spinal ventral EDAVFs were primarily fed by somatic branches. EDAVFs can be successfully treated by endovascular techniques selected based on the drainage type of the AVF.

Selective transarterial embolization with n-butyl-2-cyanoacrylate for the treatment of arterial hemorrhage after third molar extraction.

INTRODUCTION: Comprehensive reports concerning selective embolization for arterial bleeding from third molar removal have not been published. We analyzed cases of arterial bleeding from third molar extraction that required transarterial embolization, and we demonstrate representative cases. METHODS: Five consecutive patients (three men and two women, aged 24 to 37 years) who underwent transarterial embolization at our institution were included in this study. Four of them showed postoperative bleeding after lower third molar removal, and one suffered bleeding after upper third molar extraction. The period of time from extraction to embolization varied from 5 h to 5 weeks. RESULTS: Angiography revealed pseudoaneurysms at the inferior alveolar artery in four cases and at the superior alveolar artery in one case. The pseudoaneurysms were selectively embolized using 25-33 % n-butyl-2-cyanoacrylate (NBCA)-lipiodol. All of the cases showed good results angiographically and clinically. Transit hypoesthesia at the region of the mental nerve was observed in one patient. CONCLUSION: Selective transarterial embolization is an effective technique for arterial bleeding from third molar removal when it is difficult to obtain hemostasis by dental procedures. Injection of NBCA can be useful when the alveolar artery is too small to embolize with coils.

Utility of a Steerable Microcatheter for the Selective Transvenous Embolization of Dural Arteriovenous Fistulas.

Objective: Selective transvenous embolization (sTVE) is an effective technique for treating dural arteriovenous fistulas (DAVFs); however, selective catheterization into the shunted pouch is often difficult due to the acute angle of the access route between the target pouch and dural sinus. We present our initial experience using a steerable microcatheter (SM) to manually control the tip angle for selective catheterization and sTVE of DAVFs. Methods: Thirteen consecutive cases of DAVFs and 16 procedures that involved sTVE using SM between October 2016 and October 2018 were reviewed. SMs were used for selective catheterization of shunted venous pouches and/or the affected sinus and coil embolization. We evaluated the maneuverability of the SM, the success of selective catheterization into the target lesions, and the results of endovascular treatments. Results: Endovascular procedures were performed in a single session in 10 cases and in two staged sessions in 3 cases. There was no difficulty in maneuverability of the SM. Successful selective catheterization was achieved in 26 of 27 target lesions. Immediately after embolization, angiography showed complete occlusion in 10 cases and marked reduction in 3 cases. During 40.9 months of mean follow-up, 12 cases showed complete occlusion and one case showed a small residual shunt on MRI. Procedure-related complications of spontaneous thrombosis of the affected sinus were observed in one case. There were no cases of recurrence or exacerbation during follow-up. Conclusion: SM is useful for selective catheterization for target lesions during sTVE of DAVFs.