Liquid Embolization Research Articles

The LAVA Study: A Prospective, Multicenter, Single-arm Study of a Liquid Embolic System for Treatment of Peripheral Arterial Hemorrhage

PurposeTo present the results of the Liquid Embolization of Arterial Hemorrhages in Peripheral Vasculature (LAVA) study evaluating safety and efficacy of Lava Liquid Embolic System (Lava LES), an ethylene vinyl alcohol (EVOH), for peripheral arterial hemorrhage (PAH). Materials and MethodsLAVA was a pivotal, prospective, multicenter, single-group, centrally adjudicated study of adults with active PAH. Patients received EVOH at one of two viscosities, administered by experienced physicians. Primary safety endpoint was freedom from 30-day major adverse events (MAE) defined as ischemia/infarction of target territory, non-target embolization, allergic reaction, and catheter breakage/entrapment. Primary efficacy endpoint was 30-day clinical success defined as absence of bleeding from target lesion after embolization without need for emergency surgery, re-embolization, or other target lesion re-interventions. Secondary endpoints included serious adverse events and mortality. Results113 patients (mean age 57.4 years [SD 18.0; range 18.0-93.0]; 63.7% male) with 148 lesions were enrolled at 19 US centers. Targeted areas included non-gastrointestinal (GI) visceral arteries (31.1%), kidneys (26.3%), upper GI (11.5%), lower GI (6.8%) and extremities (6.1%). Empiric embolization was performed for 20.9% of lesions. The primary efficacy endpoint was achieved in 94.3% of lesions (95.3% patients), exceeding the performance goal of 72%. Two target lesions treated with EVOH required subsequent re-embolization. No surgeries were performed for bleeding or ischemia. There were no MAEs reported per study definition. All-cause mortality rate at 30 days was 8.3%. ConclusionsThe LAVA study suggests that EVOH is effective and can be safely used as an embolic agent for treatment of PAH.

Posterior short ciliary arteries ischemia following embolization of anterior ethmoid artery to treat dural arteriovenous fistulas: a case report

BackgroundThe Onyx™ Liquid Embolic System is a non-adhesive liquid embolic agent, which has been proved by the US FDA for embolization of lesions in the peripheral and neurovasculature since 2005. We reported a case of ischemic optic neuropathy after using Onyx-18 to embolize the anterior ethmoid arteries that feeding dural arteriovenous fistulas (DAVF).Case presentationA 57-year-old Asian male presented with anterior cranial fossa DAVF underwent embolotherapy by delivering Onyx-18 through a microcatheter into the anterior ethmoid arteries under angiography guidance. The interventional procedure was successful and no clear evidence was found pointing to untargeted occlusive embolus. But after the surgery the patient experienced delayed painless vision loss in the right eye (RE). The fundoscopy showed unilateral papilledema with pale optic disc in RE, accompanied by significant edema and thickening in the retinal nerve fiber layer (RNFL) of macula. The fundus fluorescence angiography showed that most of the optic disc in RE had postponed or absent fluorescence filling. Visual evoked potential (VEP) confirmed that the amplitude of the P100 component was decreased in RE without significant prolongation of the latency. The patient was diagnosed with anterior ischemic optic neuropathy, but immediate pulse steroid therapy failed to rescue his vision.ConclusionPreoperative evaluation of the patient’s hemodynamic status and fundus examination are essential for assessing the risk of ischemic ocular complications, and the non-adhesive liquid embolic agent Onyx-18 should be used cautiously during endovascular embolization of intracranial artery.

Stand-alone transarterial flow diversion for treatment of carotid cavernous fistulas

ObjectiveCarotid-cavernous fistulas (CCFs) are rare arteriovenous communications allowing blood to flow from the carotid artery into the cavernous sinus. Although currently coil and/or liquid embolization remain the preferred treatment methods for CCFs, flow diverters (FD) stents represent a viable alternative to traditional embolization techniques. This study explores both the technical aspects and rationale behind using FD stents as a stand-alone treatment approach for CCFs. MethodsThe study includes records of 7 patients with CCFs treated at two comprehensive stroke centers from 2019 to 2023. Patients treated with FD stenting in conjunction with coil and/or liquid embolization were excluded from the study. ResultsFive patients were diagnosed with direct CCFs and 2 patients with indirect CCFs. Six patients were treated with the Surpass Evolve FD stent and 1 patient with the Pipeline FD stent. DSA follow-up was performed for an average duration of 14.4 months following FD placement. Complete fistula obliteration with no residual shunting was observed in all patients. Furthermore, all patients experienced a complete resolution of symptoms following treatment. ConclusionsThe authors’ experiences suggest the efficacy and safety of FD stenting as a stand-alone treatment option for CCFs. Compared to embolization, FD stents can better preserve the parent vessel and promote healing with less associated mass effect. Despite being a retrospective self-assessment with a relatively small sample size, to the authors’ knowledge, this study represents the largest individual case series of patients with CCF treated with stand-alone FD stenting.

Initial Experience with Embolization Using a Shear-Thinning Conformable Hydrogel Embolic

A new conformable embolic agent (Obsidio; Boston Scientific, Marlborough, Massachusetts) is indicated for embolizing hypervascular tumors and treating peripheral vessel bleeding. It is a non-Newtonian hydrogel that becomes less viscous when shear force is applied. This retrospective study examined the safety and effectiveness of the shear-thinning embolic in a single-academic-center experience. Technical and clinical success were assessed. Adverse events were defined per the Society of Interventional Radiology (SIR) Adverse Events Classification. Twenty-seven patients were treated with the shear-thinning embolic in 39 vessels over 28 procedures. Technical success was achieved in 37 (95%) of 39 vessels, with clinical success in 26 (93%) of 28 procedures. There was 1 treatment-related severe adverse event (3.6%): left gastric artery embolization resulting in ischemia and subtotal gastrectomy (Grade 4). Two patients (7.1%) had mild adverse events. Initial experience showed effectiveness of this shear-thinning embolic; however, this embolic behaved differently from conventional liquid embolics, and operator training is required for safe use.

Biocompatible Liquid Embolic for the Treatment of Microvascular Hemorrhage.

Persistent or recurrent bleeding from microvessels inaccessible for direct endovascular intervention is a major problem in medicine today. Here, an innovative catheter-directed liquid embolic (P-LE) is bioengineered for rapid microvessel embolization to treat small vessel hemorrhage. Tested in rodent, porcine, and canine animal models under normal and coagulopathic conditions, P-LE outperformed clinically used embolic materials in both survival and non-survival experiments, effectively occluding vessels as small as 40 microns with no signs of recanalization. P-LE occlusion is independent of the coagulation cascade, and its resistance to displacement is ≈ 8 times greater than systolic blood pressure. P-LE is also found to be biocompatible and x-ray visible and does not require polymerization or a chemical reaction to embolize. To simulate the clinical scenario, acute microvascular hemorrhage is created in the pig kidney, liver, or stomach; these are successfully treated with P-LE achieving immediate hemostasis. Furthermore, P-LE is found to be bactericidal to highly resistant patient-derived bacteria, suggesting that P-LE may also protect against infectious complications that may occur following embolization procedures. P-LE is safe, easy to use, and effective in treating -microvessel hemorrhage.

Repeat ProstaticArtery Embolization with the Addition of a Liquid Embolic Agent: Short-term Results.

The long-term effectiveness of prostatic artery embolization (PAE) can be hampered by the recanalization of the previously embolized prostatic arteries (PA). The use of a liquid embolic agent (LEA) could limit this risk. The purpose of this study was to assess the safety and efficacy of repeat PAE (rePAE) using a LEA (Squid Peri) coupled with microspheres in patients experiencing recurring symptoms after initial embolization. This retrospective single-center study included all consecutive patients who underwent rePAE using Squid Peri coupled with microspheres. Angiographic patterns of prostatic revascularization were identified. Outcomes were assessed at the 3-month follow-up using the International Prostate Symptom Score (IPSS) and the Quality of Life (QoL) score. The primary endpoint was clinical success defined as an IPSS <18 with >25% decrease and a QoL score ≤3 with ≥1 point decrease. Safety was assessed by using the modified Clavien-Dindo classification. 30 consecutive men (mean age: 67.1±9.5 years) were included. Recanalization of the previously embolized PA was found in 83.3% of patients. Technical success was 93.3%. Median follow-up was 4.9 months [IQR: 3.9 - 9.8]. Clinical success rate was 76.7%, with a mean decrease in IPSS of -9.3±7.3 (p<0.001) and a median decrease in QoL of -2 [IQR: -4 - -1] (p<0.001). One patient presented with an acute urinary retention requiring readmission (grade IIIa complication). Repeat PAE using Squid Peri coupled with microspheres is safe and effective for patients with recurring symptoms after initial embolization.

Transverse Sinus / Sigmoid Sinus

The transverse sinus(TS)and sigmoid sinus(SS)are common sites for dural arteriovenous fistulas, and an understanding of vascular anatomy is important when developing treatment strategies. In recent years, transarterial embolization, with a liquid embolization material, has become the treatment of choice, preserving the sinus without extensive coil filling of the affected sinus. With this expansion of therapeutic options, we feel that an understanding of the microanatomy has become more important. For example, the exact site where the vein of Labbé joins the TS should be determined. This article focuses on the development and anatomy of the TS and SS and makes points that should be considered when treating dural arteriovenous fistulas.

Sealing of Iatrogenic Distal Coronary Artery Perforation by Liquid Embolization Agent—A Case Report

Percutaneous coronary intervention (PCI) is one of the most commonly performed cardiovascular interventions to treat significant coronary artery stenosis. Although a safe procedure, it carries the risk of complications like coronary artery perforation (CAP), bleeding, stroke, and acute kidney injury rarely resulting in death. The incidence of CAP is 0.84% of all PCI procedures and the incidence is increasing as cardiologists are accepting more and more challenging cases. CAP is caused by a guidewire (GW) or a vessel tear from balloon angioplasty, stenting, or rotational atherectomy. Though the majority of CAPs do not result in cardiac tamponade, some do lead to tamponade and death. The majority of distal wire perforations respond to prolonged balloon inflation, coils, glue, or fat embolization. Herein, we report a case of distal CAP in a 63-year-old woman occurring following left circumflex artery PCI caused by the exiting of coronary GW. The CAP was successfully sealed by the liquid embolization technique using ONYX. First described in 1990, Onyx is an elastic polymer composed of ethylene vinyl alcohol copolymer dissolved in dimethyl sulfoxide and mixed with micronized tantalum powder (Onyx). The Onyx is predominantly used by interventional radiologists while performing neurovascular and peripheral vascular interventions. There were only a few case reports of plugging of CAPs using Onyx. Our case highlights the safety and feasibility of closing distal CAPs using Onyx.

Multicenter US clinical experience with the Scepter Mini balloon catheter.

Distal navigability and imprecise delivery of embolic agents are two limitations encountered during liquid embolization of cerebrospinal lesions. The dual-lumen Scepter Mini balloon (SMB) microcatheter was introduced to overcome these conventional microcatheters' limitations with few small single-center reports suggesting favorable results. A series of consecutive patients undergoing SMB-assisted endovascular embolization were extracted from prospectively maintained registries in seven North-American centers (November 2019 to September 2022). Fifty-four patients undergoing 55 embolization procedures utilizing SMB were included (median age 58.5; 48.1% females). Cranial dural arteriovenous fistula embolization was the most common indication (54.5%) followed by cranial arteriovenous malformation (27.3%). Staged/pre-operative embolization was done in 36.4% of cases; and 83.6% of procedures using Onyx-18. Most procedures utilized a transarterial approach (89.1%), and SMB-induced arterial-flow arrest concurrently with transvenous embolization was used in 10.9% of procedures. Femoral access/triaxial setups were utilized in the majority of procedures (65.5% and 60%, respectively). The median vessel diameter where the balloon was inflated of 1.8 mm, with a median of 1.5 cc of injected embolic material per procedure. Technical failures occurred in 5.5% of cases requiring aborting/replacement with other devices without clinical sequelae in any of the patients, with SMB-related procedural complications of 3.6% without clinical sequelae. Radiographic imaging follow-up was available in 76.9% of the patients (median follow-up 3.8 months), with complete occlusion (100%) or >50% occlusion in 92.5% of the cases, and unplanned retreatments in 1.8%. The SMB microcatheter is a useful new adjunctive device for balloon-assisted embolization of cerebrospinal lesions with a high technical success rate, favorable outcomes, and a reasonable safety profile.

Construction of an Injectable Composite Double-Network Hydrogel as a Liquid Embolic Agent.

Conventional embolists disreputably tend to recanalization arising from the low filling ratio due to their rigidity or instability. As a result, intelligent hydrogels with a tunable modulus may meaningfully improve the therapeutic efficacy. Herein, an injectable composite double-network (CDN) hydrogel with high shear responsibility was prepared as a liquid embolic agent by cross-linking poly(vinyl alcohol) (PVA) and carboxymethyl chitosan (CMC) via dynamic covalent bonding of borate ester and benzoic-imine. A two-dimensional nanosheet, i.e., layered double hydroxide (LDH), was incorporated into the network through physical interactions which led to serious reduction of yield stress for the injection of the hydrogel and the capacity for loading therapeutic agents like indocyanine green (ICG) and doxorubicin (DOX) for the functions of photothermal therapy (PTT) and chemotherapy. The CDN hydrogel could thus be transported through a thin catheter and further in situ strengthened under physiological conditions, like in blood, by secondarily cross-linking with phosphate ions for longer degradation duration and better mechanical property. These characteristics met the requirements of arterial interventional embolization, which was demonstrated by renal embolism operation on rabbits, and meanwhile favored the inhibition of subcutaneous tumor growth on an animal model. Therefore, this work makes a breakthrough in the case of largely reducing the embolism risks, thus affording a novel generation for interventional embolization.

Should Coronary Artery Fistula Be Treated? A Review Throughout a Case Series

Background: Coronary artery disease (CAD) includes a wide spectrum of entities beyond the atherosclerotic disease. Coronary artery fistulas (CAF) represent an uncommon vascular abnormality that may cause several cardiovascular complications and symptoms, due to the coronary steal phenomena. Surgical or percutaneous closure should always be considered. The authors present a case series of patients with CAFs who developed cardiovascular manifestations, and underwent percutaneous closure safely and feasibly, with good clinical results. Case Summary: Five patients with CAFs were treated from 2021–2023; three were male (60%), the mean age was 59 years, the most common symptom was chest pain, and two patients presented in the context of unstable angina. The authors documented pulmonary hypertension in three patients, none of them with haemodynamic compromise of right ventricle. Two of the patients had documented ischaemia or haemodynamic significance due to the CAF. Finally, in two cases, no CAD was noted in coronary angiography. Percutaneous closure was done using a 6 Fr or 7 Fr sheath; guiding catheter 6 or 7 Fr through a workhorse guidewire, a microcatheter was placed in the coronary origin of the fistula, closure was done using a liquid embolisation system or delivering coils into the defect. The number and length of coils may vary depending on the fistula’s size. Discussion: The authors present five successful cases of percutaneous closure of symptomatic CAF, who presented with angina or dyspnoea as main symptoms. Once the diagnosis was made and further studies performed, the closure was decided based on the pulmonary hypertension or coronary steal phenomena.

Comparison of outcomes with/without preoperative embolization for meningiomas with diluted N-butyl-2-cyanoacrylate

BackgroundPreoperative embolization for meningiomas is controversial regarding its effectiveness in reducing intraoperative blood loss and operative time. In contrast, some reports have documented improved surgical outcomes in large meningiomas. In this study, we retrospectively compared the outcomes of craniotomy for meningiomas with/without preoperative embolization with diluted N-butyl-2-cyanoacrylate (NBCA) primarily in a single institution. MethodsData (World Health Organization grade, Simpson grade, maximum tumor diameter, intraoperative bleeding, operative time, history of hypertension, and time from embolization to craniotomy) of patients with initial intracranial meningiomas were compared with or without preoperative embolization from January 2015 to April 2022. ResultsThe embolization group consisted of 56 patients and the nonembolization group included 76 patients. Diluted NBCA (13% concentration for all patients) was used in 51 of 56 patients (91.1%) who underwent transarterial embolization. Permanent neurological complications occurred in 2 (3.6%) patients. Intraoperative bleeding was significantly lower in the embolization group for a maximum tumor diameter ≥40 mm (155 vs. 305 ml, respectively, p < 0.01). In the nonembolization group, for a maximum tumor diameter ≥30 mm, patients with hypertension had more intraoperative bleeding than non-hypertensive ones. ConclusionsDespite its limitations, the present results showed that, under certain conditions, preoperative embolization for intracranial meningiomas caused less intraoperative bleeding. The safety of treatment was comparable with that reported in the Japan Registry of NeuroEndovascular Therapy 3 (JR-NET3) with a complication rate of 3.7% for preoperative embolization of meningiomas, despite the treatment focused on the liquid embolization material.

Onyx Liquid Embolic Agent: Basic Knowledge for Its Use in Interventional Neuroradiology

Onyx Liquid Embolic Agent: Basic Knowledge for Its Use in Interventional Neuroradiology

Abstract 088: Treatment of a Ruptured AVM with Inflow Aneurysms: Mixed approach using coil and liquid embolization

Introduction Arteriovenous malformations(AVMs) are high‐flow vascular abnormalities characterized by direct communications between arteries and veins of various complexities. Cerebral AVMs may manifest with new‐onset seizures or intraparenchymal (IPH) or subarachnoid hemorrhages (SAH). Life‐threatening bleeds may occur from the AVM nidus or associated aneurysms. We report a patient with hemorrhage from a complex AVM that included a prominent nidus and large inflow aneurysms requiring several endovascular techniques for treatment. Methods N/A Results A 35 year old male patient newly arrived from the Philippines with a history of hypertension presented to the hospital after being found unresponsive at home with frothing from the mouth and incontinence. The patient regained consciousness in the ER, complaining of a posterior headache which he had been experiencing for a week. NIHSS of 0 was noted with no neurological deficits. CT‐head revealed extensive SAH in interhemispheric falx anterior to and outlining the entire corpus callosum with intraventricular extension. CT‐ angiogram demonstrated a prominent AVM with a well‐developed nidus situated to the left of midline about the posterior corpus callosum. Two large inflow aneurysms, felt to be the rupture site, projecting from the proximal left pericallosal artery were also demonstrated. An incidental ACA aneurysm was also noted. Cerebral angiography redemonstrated these findings as well as the drainage of the AVM primarily through the straight sinus. Graded as Spetzler Martin 4. Common femoral approach was used. An access catheter was passed into the left ICA. The pericallosal artery was accessed with a detachable tip microcatheter which was further advanced past the inflow aneurysms into the main pedicle feeding the AVM nidus. The inflow aneurysms were accessed and embolized with coils using a second microcatheter prior to AVM embolization. This sealed off access to the aneurysms and parent vessel against liquid agent backflow. Onyx‐18 was then injected into the main AVM pedicle under a blank roadmap. Extensive but partial filling of the AVM was noted anteriorly but full embolization of the posterior aspect of the nidus was not achieved. Finally coiling of the ACA aneurysm was performed after accessing the right ICA. An MRI with and without contrast was performed and an expected acute infarction in the left ACA territory was observed. A repeat angiogram was performed a week later revealing posterior cerebral artery and posterior choroidal branches feeding the posterior 1/3 of the AVM. Embolization of three posterior feeding pedicles was subsequently performed utilizing dilute NBCA. Because of coil impaction the proximal pericallosal inflow aneurysm required re‐treatment with further coil placement 8 months after initial treatment. The patient has regular angiograms to monitor the AVM, which appears stable without significant residual shunting. Conclusion Ruptured AVMs are fatal events requiring careful treatment to prevent further bleeding while preserving viable brain tissue. AVMs are fragile formations of vessels which can receive collaterals from multiple targets and often have associated high risk features like inflow aneurysms. Accordingly endovascular treatment may require a mixture of techniques to ensure adequate and safe embolization. Regular monitoring of these structures and adjacent vessels is required to prevent any poor outcomes.

Abstract 139: Super Distal Access using the Vecta46 Intermediate Catheter in Embolization of the MMA for cSDH

Introduction There is increasing literature to support the efficacy of middle meningeal artery (MMA) embolization in the treatment of chronic subdural hematomas (cSDH). Techniques for optimal embolization of the MMA are yet to be elucidated. We hypothesized utilization of a novel 046” intermediate catheter within the proximal MMA trunk carry procedural advantages for multiple pedicle embolizations and ease of navigation to distal MMA vasculature. Methods We retrospectively reviewed and analyzed a prospectively maintained IRB‐approved database of the senior authors. Results Twenty‐one (21) consecutive cases of Vecta46 utilization with MMA embolization were identified (2023), in patients 69±13 years (range 49‐83 years), 4 (19%) women. Four (19%) patients were on antiplatelet/anticoagulants. At presentation, recurrent cSDH in 9 patients (43%) were previously managed with burr holes (n=2, 22%), craniotomy (n=3, 33%), or without drainage (n=4, 44%). Average admission cSDH thickness was 8.8±1.6mm, midline shift of 3±0.7mm. Access was performed through a 5‐ or 6‐French arteriotomy. Both anterior and posterior MMA branches were embolized in 16 (76%) cases, and adjunctive coiling of the proximal MMA trunk was performed in all cases. Vecta46 was successfully placed in the proximal MMA trunk in all cases. There were no vessel irregularities, vasospasm, or dissection noted along the course of the MMA Vecta46 placement. No immediate procedural complications were noted and all cases achieved complete distal MMA occlusion. Figure 1: (A) Ophthalmic (black) and petrous (white) collaterals off the anterior and posterior MMA branches, respectively. (B) Contralateral (green) and falx (orange) penetration of the MMA branches. (C) Proximal coiling of the anterior and posterior MMA branches (black). Conclusion The Vecta46 intermediate catheter is a powerful tool for MMA embolization that allows the safe and effective placement of an intermediate catheter in the proximal MMA trunk. This allows for simple catheter exchange for multiple liquid embolic pedicle embolizations and significant support for navigating microcatheters to distal MMA branches.

Transvenous Embolization of Dural Arteriovenous Fistulas Through the Galenic (Deep Venous) System: Multicenter Case Series and Meta-Analysis.

Arteriovenous fistulas involving the deep venous system have often been treated with microsurgery or transarterial embolization. Increasing familiarity with transvenous navigation and improved endovascular access systems may facilitate transvenous embolization (TVE) for these rare and challenging lesions. We performed a retrospective study of neurointerventional databases of 6 high-volume centers. We identified all cases of arteriovenous fistulas with deep transvenous embolizations for arteriovenous fistula. Details regarding demographics, fistula characteristics, treatment considerations, clinical outcomes, and fistula occlusion were obtained and analyzed. The meta-analysis used the same inclusion criteria. Seventeen cases of TVE were identified. The most common reasons for TVE included prior treatment failure with microsurgery (n = 2) or transarterial embolization (n = 3) or inaccessible arterial pedicles (n = 4). For patients with full clinical outcome data (n = 14), 2 patients had worsened modified Rankin Scale, 8 patients had no change, and 4 were improved at a median clinical follow-up of 3.5 months. Angiographic obliteration was achieved in 15/17 cases (88.2%). In 1 case, catheterization around a sharp turn in the basal vein of Rosenthal could not be performed. In another case, despite successful TVE, there was residual lesion which was treated 1 year later by microsurgical clipping and excision. Transvenous approaches for embolization of deep arteriovenous fistulas have become possible with modern endovascular catheter systems and liquid embolics. These lesions can be treated safely and effectively through endovascular approaches, which may spare patients the traversal of deep structures needed for microsurgical approaches to these regions. The outcomes of TVE are comparable with published outcomes of microsurgical interruption.

Neuroendovascular Surgery Applications in Craniocervical Trauma.

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Copolymer liquid embolization of dural arteriovenous fistulas: A 20-year single-center experience.

Dural arteriovenous fistulas (DAVFs) with cortical venous drainage (CVD) carry significant risks of cerebral ischemia and intracranial hemorrhage. Endovascular treatment (EVT) using Onyx, a copolymer-based liquid embolic material, has become the preferred approach. However, the optimal treatment strategy for anterior cranial fossa DAVFs remains debated. This retrospective study analyzed outcomes of EVT for DAVFs in a single center from 2002 to 2023. Patient data including demographics, clinical status, angiographic findings, embolization techniques, and outcomes were recorded. The results of the anterior fossa malformations were analyzed separately afterward. A total of 195 DAVFs were included in the study. The most common presenting symptom was hemorrhage (41%), most fistulas were located in the transverse and sigmoid sinus region (48%), and the majority of DAVFs had direct CVD (78%). Transarterial embolization with Onyx was the preferred treatment strategy in majority of cases (92%). Overall, 94% of patients showed improvement or stability on the modified Rankin Scale. Two patients died due to rebleeding after partial DAVF embolization. Onyx demonstrated higher immediate complete occlusion rate compared to other embolic materials (88% vs. 35%). Overall, 91% of fistulas were closed at the last follow-up. Ten anterior fossa DAVFs were treated, resulting in clinical improvement and complete occlusion in all cases. Based on the results of our study, we believe that a cure of DAVFs, including those in the anterior fossa, can be achieved in more than 90% of cases through transarterial Onyx embolization, given long-term clinical experience.

Solvent Exchange Induced In Situ Formed Hydrogel as Liquid Embolic Agents

AbstractEndovascular embolization can selectively deploy embolic agents into diseased or injured blood vessels to complete the treatment. However, traditional embolic agents still face challenges, such as poor intravascular diffusivity, non‐biodegradable, unstable mechanical properties, radiolucency, and recanalization. Herein, we report a poly (lipoic acid‐tannic acid)/tromethamine/Galinstan (PLTTG) dimethyl sulfoxide (DMSO) solution‐derived hydrogel liquid embolic agent. By injecting PLTTG DMSO solution into body fluids, a PLTTG hydrogel can be formed in situ owing to the solvent exchange induced intra‐ and inter‐polymer hydrogen bonding and electrostatic interactions. Moreover, the gelation time and injection forces of the solution as well as the mechanical properties and embolic pressure of the obtained hydrogels can be adjusted by changing the concentration of PLTTG. The PLTTG hydrogel can effectively embolize the renal artery and femoral vein without recanalization and displacement in rabbit models. Furthermore, the hydrogel can embolize the ruptured femoral artery to arrest active bleeding. Owing to the advantages of the hydrogel, including adjustable gelation time, mechanical properties, viscosities, injection forces, and embolic pressure, as well as good biocompatibility and biodegradability, radiopacity, excellent embolization performance and intravascular diffusivity, easy usage, low cost, allowing it to be a potential embolic agent to treat multiple vascular diseases in clinic.

Endovascular Treatment of Dural Arteriovenous Fistulas in a Medium-Sized Scandinavian Neurovascular Center

Endovascular treatment is the primary treatment modality for dural arteriovenous fistulas (DAVFs). We performed a retrospective analysis of DAVFs treated in our hospital to determine if high-quality endovascular treatment can be provided in a medium-volume vascular center. From 2007 to 2021, 69 DAVF treatments were undertaken in our hospital. Of these DAVFs, 55 were endovascular, 11 were open surgical procedures, and 3 were Gamma Knife treatments. Of the endovascular treatments, 10 (18.2%) were in ruptured DAVFs. The most common location of endovascularly treated DAVFs was at the transverse/sigmoid sinus (32.7%) and at the cavernous sinus (25.5%). Of the endovascularly treated DAVFs, 38.2% were low-grade fistulas (Cognard I/IIa), whereas 61.8% were high-grade fistulas (Cognard ≥IIb). 58.2% of fistulas were treated transarterially. DAVFs located in the cavernous sinus were treated using coils alone, whereas most other DAVFs were treated with liquid embolics alone or in combination with coils. Complete or near-complete cure was achieved in 74.5% of treatments, whereas 18.2% of treatments resulted in downgrading of the fistula. Twelve patients were retreated once (9 endovascularly) and 1 patient was retreated twice. After retreatment, complete or near-complete cure was achieved in 86.4% of patients. 72.7% of treatments were performed without any remnant or retreatment. There were no procedure-related deaths. One patient experienced a complication resulting in permanent neurologic deficits. Seven other complications (12.7%) were recorded, all asymptomatic or causing only temporary symptoms. Based on our findings, we conclude that high-quality treatment of DAVFs can be provided in a medium-volume vascular center.