Liquid Embolization Research Articles

Efficacy of Liquid Embolic Agent Treatment in Hemorrhagic Peripheral Intracranial Aneurysms: A Single-Center Experience.

Objective: To evaluate the efficacy of liquid embolization agents for treating various hemorrhagic peripheral intracranial aneurysms. Methods: We retrospectively analyzed 38 patients who suffered from hemorrhagic peripheral intracranial aneurysms and were treated with liquid embolization agents. We used the modified Rankin scale for follow-up at 6 months postoperatively, and digital subtraction angiography follow-up was performed 6 months postoperatively. Results: Of the 38 patients (ten of simple peripheral intracranial aneurysms, six of Moyamoya disease (MMD), and 22 of arteriovenous malformation (AVM)), posterior circulation accounted for the most significant proportion (57.9%), followed by anterior circulation (21.1%) and intranidal aneurysms (21.1%). Intraoperative hemorrhage occurred in four cases, postoperative cerebral infarction occurred in four cases, two patients encountered microcatheter retention, and intraoperative thrombosis took place in the basilar artery of a patient with an arteriovenous malformation. A postoperative hemorrhage occurred in only one patient. At 6-month follow-up, 84.2% of patients had good prognosis outcomes, and 13.5% had poor outcomes. Conclusion: Liquid embolization agents are effective for hemorrhagic peripheral intracranial aneurysms; however, safety depends on the subtypes. For peripheral hemorrhagic aneurysms in MMD, the vessel architecture must be carefully evaluated before embolization.

Evaluation of an in vivo preclinical model for human middle meningeal artery embolization using the posterior intercostal artery of the swine

BackgroundEmbolization of the middle meningeal artery (MMA) is a promising minimally invasive technique that is gaining traction in the treatment of chronic subdural hematoma. Unfortunately, the human meninges and associated...

Protein-based polymer liquid embolics for cerebral aneurysms

Cerebral aneurysms (CA), an abnormal bulge in the arteries that supply blood to the brain, are prone to rupture and can cause hemorrhagic stroke. Physicians can treat CA by blocking blood flow to the aneurysmal sac via clipping of the aneurysm neck via open procedure, or endovascular occlusion of the aneurysm with embolic materials to promote thrombus formation to prevent further inflow of blood into the aneurysm. Endovascular treatment options for CA still have significant limitations in terms of safety, usability in coagulopathic patients, and risks of device migration. Bioactive embolic therapies, consisting of non-toxic bioresorbable materials that encourage the growth of neointima across the aneurysm neck, are needed to improve the healing of CA. In this work, the bioinspired silk-elastinlike protein-based polymer (SELP 815K), was used to embolize aneurysms in a rabbit elastase model. SELP 815K effectively embolized the model aneurysms in vivo, achieving >90% occlusion, using commercial microcatheters. No device-associated adverse effects were observed in any of the animals, and SELP 815K showed no cytotoxicity. SELP embolization did not show any deleterious effects to local tissues, and features consistent with reendothelialization of the aneurysm neck were noted in histological examination one-month post-embolization. SELP 815K shows promise as an embolic treatment for unruptured CA. Statement of significanceUnruptured cerebral aneurysms are present in approximately 3% of the population, with a fatality rate of up to 65% upon rupture. In this work a silk-elastinlike protein polymer (SELP) is explored as a liquid embolic for occlusion of cerebral aneurysms. This embolic exists as a liquid at room temperature before rapidly forming a gel at physiological temperature. This shape filling property was used to successfully occlude cerebral aneurysms in rabbits, with stable occlusion persisting for over thirty days. SELP occlusions show evidence for reendothelialization of the aneurysm sac and provide an opportunity for delivery of bioactive agents to further improve treatments.

Liquid Embolization of Peripheral Arteriovenous Malformations with Ethylene-Vinyl Alcohol Copolymer in Neonates and Infants.

In the postnatal period, extensive peripheral arteriovenous malformations (AVM) are associated with high morbidity, especially when localized in the liver. Their urgent treatment is always a challenging problem in neonates and infants. We analyzed four consecutive children aged three days to three years who underwent eight liquid embolization procedures with ethylene-vinyl alcohol copolymer. The AVM were situated on the thoracic wall, in the liver, and on the lower leg. In three cases, the malformations showed total regression. The tibial AVM degenerated widely. If impaired beforehand, cardiac or hepatic function normalized after the interventions. There were no embolization-associated complications such as nontarget embolization or tissue ischemia. We conclude that application of ethylene-vinyl alcohol copolymer seems to be a safe therapeutic option and can be used in neonates and infants with peripheral AVM in consideration of the agent's characteristics. Nevertheless, there are still hardly any data concerning young children.

Endovascular embolisation of external carotid artery system haemorrhage in radiated nasopharyngeal carcinoma.

To review the effectiveness and safety of embolisation in managing haemorrhage from the external carotid artery (ECA) system in radiated nasopharyngeal carcinoma (NPC) patients. Radiated NPC patients who presented with severe oronasal bleeding and underwent digital subtraction angiography that excluded blowouts from the internal carotid artery from 2011 to 2021 were reviewed. Those who subsequently underwent embolisation of the ECA system were analysed for technical success rate, post-embolisation re-bleeding rate and complications. Seventeen embolisations were performed in fifteen patients during the 10-year period. The technical success rate was 100%, however the early haemostatic rate (no re-bleed within 7days of embolisation) was 70.6% (12/17) and the overall long-term haemostatic rate was 58.8% (10/17). The re-bleed rates of targeted and empiric embolisations were 33.3% (3/9) and 50.0% (4/8), respectively. The re-bleed rates with liquid agents, coils and particles were 0% (0/7), 33.3% (1/3) and 85.7% (6/7), respectively. Amongst the embolisations utilising liquid agents, 71.4% (5/7) were targeted, distal embolisations. All re-bleeds underwent surgical ligation or repeat embolisation; half of them further experienced recurrent bleeding. There were no significant complications with embolisation. Although embolisation of the ECA system in NPC has a high technical success rate and is safe, re-bleeding appears to be common. Targeted, distal embolisation with liquid embolics appear to have good haemostatic effect. Clinicians should be aware that patients may need repeated procedures to secure haemostasis.

Pi-induced in-situ aggregation of sevelamer nanoparticles for vascular embolization

Decades have witnessed rapid progress of polymeric materials for vascular embolic or chemoembolic applications. Commercially available polymeric embolics range from gelatin foam to synthetic polymers such as poly(vinyl alcohol). Current systems under investigation include tunable, bioresorbable microspheres composed of chitosan or poly(ethylene glycol) derivatives, in situ gelling liquid embolics with improved safety profiles, and radiopaque embolics that are trackable in vivo. In this paper, we proposed a concept of ‘responsive embolization’. Sevelamer, clinically proved as an inorganic phosphate binder, was ground into nanoparticles. Sevelamer nanoparticle is highly mobile and capable of swelling and aggregating in the presence of endogenous inorganic phosphate, thereby effectively occluding blood flow in the vessel as it was administered as an embolic agent for interventional therapy. Moreover, citrated sevelamer nanoparticles delayed the aggregation, preferable to penetrate deeply into the capillary system. On the rabbit VX2 liver cancer model, both sevelamer particles aggregates occlude the tumor feeding artery, but backflow was found for the pristine one, thereby citrate passivation of sevelamer nanoparticles endows it have potential from ‘bench to bedside’ as a new type of vascular embolic.

Radiographic and clinical outcomes with particle or liquid embolic agents for middle meningeal artery embolization of nonacute subdural hematomas.

Middle meningeal artery (MMA) embolization is an apparently efficacious minimally invasive treatment for nonacute subdural hematomas (NASHs), but how different embolisates affect outcomes remains unclear. Our objective was to compare radiographic and clinical outcomes after particle or liquid MMA embolization. Patients who had MMA embolization for NASH were retrospectively identified from a multi-institution database. The primary radiographic and clinical outcomes-50% NASH thickness reduction and need for surgical retreatment within 90 days, respectively-were compared for liquid and particle embolizations in patients treated 1) without surgical intervention (upfront), 2) after recurrence, or 3) with concomitant surgery (prophylactic). The upfront, recurrent, and prophylactic subgroups included 133, 59, and 16 patients, respectively. The primary radiographic outcome was observed in 61.8%, 61%, and 72.7% of particle-embolized patients and 61.3%, 55.6%, and 20% of liquid-embolized patients, respectively (p = 0.457, 0.819, 0.755). Hazard ratios comparing time to reach radiographic outcome in the particle and liquid groups or upfront, recurrent, andprophylactic timing were 1.31 (95% CI 0.78-2.18; p = 0.310), 1.09 (95% CI 0.52-2.27; p = 0.822), and 1.5 (95% CI 0.14-16.54; p = 0.74), respectively. The primary clinical outcome occurred in 8.0%, 2.4%, and 0% of patients who underwent particle embolization in the upfront, recurrent, and prophylactic groups, respectively, compared with 0%, 5.6%, and 0% who underwent liquid embolization (p = 0.197, 0.521, 1.00). MMA embolization with particle and liquid embolisates appears to be equally effective in treatment of NASHs as determined by the percentage who reach, and the time to reach, 50% NASH thickness reduction and the incidence of surgical reintervention within 90 days.

Abstract No. 501 Treatment of ruptured and non-ruptured aneurysms using catheter-delivered biomaterials

Treatment of saccular aneurysms (SAs) depend on their morphology and location. Minimally invasive treatment options include coil embolization, flow diverter stents, stent-assisted coiling and liquid embolics. Many drawbacks are associated with these treatment options. To overcome these drawbacks, we developed and tested a novel biomaterial for the endovascular treatment of SAs in vitro, in cell culture, small and large animal models.

Recent Trends and In-Hospital Mortality of Transarterial Chemoembolization (TACE) in Germany: A Systematic Analysis of Hospital Discharge Data between 2010 and 2019.

Simple SummaryThe minimally invasive procedure of transarterial chemoembolization (TACE) represents a standard oncologic procedure for the treatment of intermediate-stage hepatocellular carcinoma, cholangiocarcinoma, and liver metastases. Up to now, comprehensive data on recent trends and post-interventional in-hospital mortality have been largely lacking. Therefore, the aim of our study was to provide a systematic overview of the different indications and embolization techniques, as well as to identify factors associated with increased in-hospital mortality. For this purpose, we retrospectively examined 49,595 individual cases in Germany, based on standardized hospital discharge data from the German Federal Statistical Office, over the period 2010 to 2019. As a result of our study, we were able to show a correlation of in-hospital mortality with the presence of various complications, the type of embolization used, and the annual case volume. Consequently, our study may help to reduce the mortality of this therapeutic procedure in the future.(1) Background: Transarterial chemoembolization (TACE) is a minimally invasive procedure, characterized by the selective occlusion of tumor-feeding hepatic arteries, via injection of an embolizing agent and an anticancer drug. It represents a standard of care for intermediate-stage hepatocellular carcinoma (HCC), and it is also increasingly performed in cholangiocarcinoma (CCA), as well as in liver metastases. Apart from the original method, based on intra-arterial infusion of a liquid drug followed by embolization, newer particle-based TACE procedures have been introduced recently. As yet, comprehensive data on current trends of TACE, as well as its in-hospital mortality in Germany, which could help to further improve outcome following TACE, are missing. (2) Methods: Based on standardized hospital discharge data, provided by the German Federal Statistical Office from 2010 to 2019, we aimed at systematically evaluating current clinical developments and in-hospital mortality related to TACE in Germany. (3) Results: A total of 49,595 individual cases undergoing TACE were identified within the observation period. The overall in-hospital mortality was 1.00% and significantly higher in females compared to males (1.12 vs. 0.93%; p < 0.001). We identified several post-interventional complications, such as liver failure (51.49%), sepsis (33.87%), renal failure (23.9%), and liver abscess (15.87%), which were associated with a significantly increased in-hospital mortality. Moreover, in-hospital mortality significantly differed between the underlying indications for TACE (HCC: 0.83%, liver metastases: 1.22%, and CCA: 1.40%), as well as between different embolization agents (liquid embolization: 0.80%, loaded microspheres: 0.92%, spherical particles: 1.54%, and non-spherical particles: 2.84%), for which we observed large geographic differences in their frequency of use. Finally, in-hospital mortality was significantly increased in centers with a low annual TACE case volume (<15 TACE/year: 2.08% vs. >275 TACE/year: 0.45%). (4) Conclusion: Our data provide a systematic overview of indications and embolization methods for TACE in Germany. We identified a variety of factors, such as post-interventional complications, the embolization method used, and the hospitals’ annual case volume, which are associated with an increased in-hospital mortality following TACE. These data might help to further reduce the mortality of this routinely performed local-ablative procedure in the future.

Fogarty-assisted transcatheter embolization of a large renal high-flow arteriovenous fistula

BackgroundRenal high-flow arteriovenous fistulas and its complications may involve high output heart failure, hematuria, hypertension or lethal hemorrhage.Case presentationThis case report covers the case of a 65-year-old male patient with a large renal high-flow arteriovenous fistula of the right kidney (RAVF), treated with balloon-assisted coil and liquid (n-Butyl Cyanoacrylate) embolization. By use of ballon-occlusion with an over-the-wire Fogarty catheter and advancement of a microcatheter through the lumen distal to the balloon during the transcatheter embolization of a high-flow RAVF, control of arterial blood flow is feasible by temporary occlusion of the afferent artery. This technique of flow modulation facilitates controlled deployment of embolization materials and decreases the risk of inadvertent distal embolization by use of only one 6-French (F) arterial sheath.ConclusionsBalloon-assisted embolization using a Fogarty occlusion catheter represents a feasible, safe and effective treatment option for the treatment of large, high-flow arteriovenous fistulas of the kidney.

Transarterial Embolization of Ethmoidal Dural Arteriovenous Fistula: 2-Dimensional Video.

Cranial dural arteriovenous fistulae (dAVF) are rare cerebrovascular lesions characterized by direct arteriovenous shunting within the dural leaflets, with stark heterogeneity in angioarchitecture among different patients.1,2 It is, therefore, crucial to personalize treatment strategies to unique patients and their specific lesion. The authors describe an ethmoidal dAVF in an elderly female patient with arterial supply from the ophthalmic arteries and the contralateral middle meningeal artery. This, together with recent advances in microcatheter technology and the controllability of modern liquid embolic agents, opened up a route for transarterial embolization, obviating the need to course through the ophthalmic artery or the need for open surgery.3 Onyx is Food and Drug Administration-approved for treatment of arteriovenous malformations and can be used off-label for treatment of dAVF, as described here. This video demonstrates the technical nuances and safety considerations of transarterial liquid embolization through the middle meningeal artery while providing an overview of alternative treatment approaches for ethmoidal dAVFs. The patient consented to the procedure.

Analysis of the Pial Arterial Supply as a Cause of Intraprocedural Hemorrhage During Transarterial Liquid Embolization of Tentorial Dural Arteriovenous Fistulas

Tentorial dural arteriovenous fistulas (AVFs) are bridging vein shunts, and are therefore sometimes supplied by the pial artery as well as the dural artery. Recently, intraprocedural hemorrhage from the pial artery was reported, and we experienced 2 tentorial dural AVFs with the same complication. Pure pial artery has a glomus-like structure and forms direct shunts along the draining vein, and is likely to bleed after restriction of the draining vein caused by the transarterial embolization. This study investigated the characteristics of the pial arterial supply as a cause of hemorrhage. Twenty-six tentorial dural AVFs in 25 patients treated in our institute were retrospectively investigated and the characteristics of the pial feeders responsible for bleeding were analyzed. Thirteen pial arterial feeders (pure pial feeder in 7, dilated dural branch of the pial artery in 4, and undefined in 2) were identified in 10 of the 26 tentorial dural AVFs. Pure pial feeders were responsible for bleeding in 2 tentorial dural AVFs. To prevent intraprocedural hemorrhage, differentiation of the pure pial supply from the dural branch of the pial artery is important. The infratentorial artery will supply supratentorial fistula as the dural branch after passing through the tentorium. In contrast, the supratentorialartery can supply supratentorial fistula not only asa dural branch but also as a pure pial feeder. Therefore, attribution of the fistula and the pial supply, supratentorial or infratentorial, is useful in identifying pure pial supply.

Treatment of venous malformations with tumescent-assisted sclero-embolic and ablative lasers (SEALs): Safe and effective long-term outcomes.

Perivascular infiltration of tumescent anaesthesia (TA) is an essential element of endovenous thermal ablative procedures employed to treat superficial venous disease. In addition to anaesthesia, TA is administered to achieve vessel wall approximation and to protect surrounding structures from thermal damage. However, its role in the treatment of venous malformations (VMs) has not been established. To assess the safety and efficacy of tumescent-assisted thermal and chemical ablative methods in the treatment of VMs. Adult and paediatric patients presenting with VMs were treated using a combination of endovenous laser ablation, foam embolo-sclerotherapy and liquid embolisation using n-BCA. All procedures were ultrasound-guided. Treatment outcomes were assessed in early and late follow-ups. To assess the efficacy of TA in achieving vessel wall approximation, cross-sectional lesional diameters were measured by ultrasound, before and after the administration of TA during endovenous procedures. In a 12month period, 22 patients recruited in the study presented with 27 VMs which included 23 extra-truncular lesions (16 subcutaneous and seven intramuscular) and four truncular anomalies. On average the subcutaneous lesions measured 5.5mm (1.9-24.5mm) in diameter, intramuscular lesions measured 9.2mm (5.9-15.1mm) and truncular anomalies measured 4.9mm (1.2-12mm) in diameter. Perivascular infiltration of TA resulted in a significant reduction in vessel calibre (90% reduction on average). Intramuscular VMs were less compressible with TA (69.2% reduction) compared to subcutaneous lesions (98% reduction). Truncular anomalies such as the embryonic marginal vein achieved complete approximation (100% reduction). Procedures were safely tolerated with no major complications such as thromboembolism, stroke, nerve damage or tissue necrosis. Most patients had significant clinical as well as ultrasonographic improvement. Tumescent-assisted endovenous laser ablation and foam sclerotherapy provides safe and effective outcomes in patients with a variety of VMs.

Micro-balloon-assisted embolization of anterior cranial fossa dural arteriovenous fistula via a trans-ophthalmic approach — a technical report and case series

PurposeDural arteriovenous fistulas (dAVF) account for approximately 10–15% of all intracranial arteriovenous abnormalities. dAVFs carry a significant risk of mortality, particularly in cases of acute hemorrhage, of up to 10%. A small proportion of these dAVFs are found in the anterior cranial fossa (ACF), of which the rate of hemorrhage can be as high as up to 91%. The Scepter Mini (SM) is the smallest dual-lumen micro-balloon (MB) available for neurointerventional practice. It consists of a 2.8 French outer diameter, with a 2.2 mm × 9 mm semi-compliant balloon providing a working length of 165 cm. The SM is navigated with a 0.008-inch wire making it a particularly attractive tool accessible to the pedicles normally reached with liquid embolization micro-catheters.MethodsFive consecutive patients over a 1-year period between 2020 and 2021 were evaluated and treated for ACF dAVF using a liquid embolization approach using the SM balloon. All patients were treated using ethylene–vinyl alcohol copolymer (EVOH), of which Squid 18 and/or Squid 12 were the chosen viscosities. Control angiograms were performed for all patients post-embolization.ResultsAll patients demonstrated complete occlusion of the ACF dAVF on immediate post-treatment angiography. No immediate complications were encountered; particularly, there were no reports of visual field deficit in any of the patients.ConclusionThe MB is a valuable adjunctive tool that can enhance the safety and efficacy of trans-ophthalmic embolization of ACF dAVFs, providing additional protection to the retinal and posterior ciliary arteries against unwanted reflux of liquid embolic agent.

Evaluation of a Hydrogel Liquid Embolic Agent in a Porcine Mesenteric Hemorrhage Model

PurposeTo evaluate the ability to achieve hemostasis of a new liquid embolic agent in a porcine mesenteric artery hemorrhage model. Materials and MethodsAn anticoagulated porcine mesenteric artery hemorrhage model was created using a transarterial approach. Arterial hemorrhage was the result of aspiration needle punctures and simultaneous radiofrequency current application. Ten injured mesenteric arteries in 8 swine were treated. The hydrogel liquid embolic agent under investigation, an aqueous-based and in situ polymerizing liquid embolic agent, was used to treat actively bleeding sites. At 7 days, confirmation angiography was performed, followed by necropsy. ResultsThe mesenteric arterial injuries produced persistent and angiographically visible hemorrhage before initiating embolic therapy. Arteriovenous fistulae were observed in 4 cases. Embolization led to hemostasis in 10 of the 10 bleeds (100%). The mean embolic agent delivery time was 5.3 minutes (range, 1–15 minutes) with a mean embolic agent volume of 2.9 mL (range, 0.8–5.2 mL) delivered to achieve hemostasis. Notably, 40% of the treatments embolized the injury in the artery at the treatment site while leaving the native arterial lumen patent for the 7-day term of survival. All animals survived with no clinical evidence of hemorrhage through 7 days. Necropsy did not reveal evidence of ischemia within the bowel, liver, or lung. ConclusionsA new hydrogel liquid embolic agent was found to achieve rapid and durable hemostasis in an animal model of acute mesenteric hemorrhage.

Percutaneous liver venous deprivation: outcomes in heavily pretreated metastatic colorectal cancer patients.

To evaluate liver venous deprivation (LVD) outcomes in patients with colorectal liver metastasis (CRLM) heavily pretreated with systemic and hepatic arterial infusion pump (HAIP) chemotherapies that had an anticipated insufficient future liver remnant (FLR) hypertrophy after portal vein embolization (PVE). PVE was performed with liquid embolics using a transsplenic or ipsilateral transhepatic approach. Simultaneously and via a trans-jugular approach, the right hepatic vein was embolized with vascular plugs. Liver volumetry was assessed on computed tomography before and 3-6 weeks after LVD. Twelve consecutive CRLM patients that underwent LVD before right hepatectomy or trisectionectomy were included, all previously treated with systemic chemotherapy for a mean of 11.9 months. Six patients had additional HAIP. After embolization, FLR ratio increased from 28.7%±5.9 to 42.2%±9.0 (P<0.01). Mean kinetic growth rate (KGR) was 3.56%/week±2.3, with a degree of hypertrophy (DH) of 13.8%±7.1. In the HAIP subgroup, mean KGR and DH were respectively 3.58%/week±2.8 and 14.3%±8.7. No severe complications occurred. Ten patients reached surgery after 39 days±7.5. In heavily pretreated patients, LVD safely stimulated a rapid and effective FLR hypertrophy, with a resultant high rate of resection.

Modern Liquid Embolization Agents Based on Polymers: Composition, Characteristics, and Areas of Application. Review

Modern Liquid Embolization Agents Based on Polymers: Composition, Characteristics, and Areas of Application. Review

Treatment of Ruptured and Nonruptured Aneurysms Using a Semisolid Iodinated Embolic Agent.

Saccular aneurysms (SAs) are focal outpouchings from the lateral wall of an artery. Depending on their morphology and location, minimally invasive treatment options include coil embolization, flow diverter stents, stent-assisted coiling, and liquid embolics. Many drawbacks are associated with these treatment options including recanalization, delayed healing, rebleeding, malpositioning of the embolic or stent, stent stenosis, and even rupture of the SA. To overcome these drawbacks, a nanoclay-based shear-thinning hydrogel (STH) isdeveloped for the endovascular treatment of SAs. Extensive in vitro testing isperformed to optimize STH performance, visualization, injectability, and endothelialization in cell culture. Femoral artery saccular aneurysm models in rats and in pigs arecreated to test stability, efficacy, immune response, endothelialization, and biocompatibility of STH in both ruptured and unruptured SA. Fluoroscopy and computed tomography imaging consistently confirmed SA occlusion without recanalization, migration, or nontarget embolization; STH isalso shown to outperform coil embolization of porcine aneurysms. In pigs with catastrophic bleeding due to SA rupture, STH isable to achieve instant hemostasis rescuing the pigs in long-term survival experiments. STH is a promising semisolid iodinated embolic agent that can change the standard of medical practice and potentially save lives.

Liquid Embolics: A Guide to Currently Available and Pipeline Products

AbstractOver the last decade, several publications have reported the safety and efficacy of liquid embolics in a wide range of clinical indications. The expansion of clinical scenarios in which liquid embolics are utilized has been in part driven by some of the advantages these materials hold over other embolic agents. For instance, liquid embolics do not rely on the patient's ability to form clot and can be delivered more distally then coils at times. While several liquid embolics are commercially available, and in some cases have been for decades, there are limitations to these materials as well. The potential benefits of liquid embolics combined with the limitations of available materials have led to the ongoing development of several new agents. This review aims to familiarize the reader with both available liquid embolics and those that are relatively new or in development.

In Vivo Sol-Gel Reaction of Tantalum Alkoxide for Endovascular Embolization.

Liquid embolic agents are considered the most promising for various embolization procedures because they enable deep penetration. For realizing effective procedures, the delivery of liquid embolic agents should be guided under X-ray imaging systems and the solidification time should be optimized for the specific indication. The biocompatibility of embolic agents is also crucial because they remain in the vessel after embolization. In this study, new biocompatible embolic agents based on tantalum ethoxide is synthesized. Tantalum alkoxide liquid embolics (TALE) possess the radiopacity for fluoroscopy and can control the penetration depth by modifying the sol-gel kinetics. Furthermore, TALE can serve as drug carriers for synergistic treatment. Using these excellent characteristics, it is demonstrated that TALE agents can be used in various situations including the transarterial chemoembolization of hepatocellular carcinoma and embolotherapy of massive bleeding from the femoral artery.