scholarly journals Quantification of tantalum sedimentation rates in liquid embolic agents

2018 ◽  
Vol 24 (5) ◽  
pp. 574-579 ◽  
Author(s):  
JR Mason ◽  
C Dodge ◽  
G Benndorf
Keyword(s):  
Sedimentation Rate ◽  
Arteriovenous Malformations ◽  
Sedimentation Rates ◽  
Signal To Noise ◽  
X Ray ◽  
Time Points ◽  
Embolic Agents ◽  
Covalently Bonded ◽  
Liquid Embolic ◽  
Over Time

Background Endovascular treatment (EVT) of brain arteriovenous malformations has evolved from cyanoacrylate derivatives such as N-butyl cyanoacrylate, an adhesive glue, to ethylene vinyl copolymer-based liquid embolics such as Onyx® and SQUID® dissolved in dimethyl sulfoxide. Although these agents offer several advantages, their rapidly decreasing radiopacity, as a result of the sedimentation of tantalum powder, compromises visual control during EVT. This study aims to quantify and compare tantalum sedimentation rates of several liquid embolic agents, and determine their effects on radiopacity. Methods The rate of sedimentation of liquid embolics Onyx 18®, SQUID 12®, and SQUID 18® was measured after preparation by single x-ray exposures for a period of 30 minutes. The signal-to-noise ratios (SNRs) of the suspension of each liquid embolic was calculated at various time points as tantalum settled out of the suspension. Precipitating Hydrophobic Injectable Liquid (PHIL®) was imaged as a control. Results Onyx 18® demonstrated the fastest sedimentation rate of the liquid embolics analyzed and demonstrated a threefold faster drop in SNR compared to SQUID 18® over 30 minutes. Onyx 18® demonstrated a one and a half times faster drop in SNR compared to SQUID 12®. Although PHIL 25® maintained constant SNR over the same time, it was lower at baseline immediately after preparation compared to tantalum-based liquids. Conclusion Caution during long injections using tantalum-based agents is advised. Onyx 18® has a significantly faster drop in radiopacity compared to SQUID 12® and SQUID 18®. Covalently bonded iodine-based embolics like PHIL® demonstrate constant radiopacity over time.

scholarly journals Liquid Embolic Agents in Spectral X-Ray Photon-Counting Computed Tomography using Tantalum K-Edge Imaging

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Isabelle Riederer ◽  
Daniel Bar-Ness ◽  
Melanie A. Kimm ◽  
Salim Si-Mohamed ◽  
Peter B. Noël ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Photon Counting ◽  
X Ray ◽  
Embolic Agents ◽  
Liquid Embolic

Neurological outcomes and cure rates of embolization of brain arteriovenous malformations with n-butyl cyanoacrylate or Onyx: a meta-analysis

2014 ◽  
Vol 8 (3) ◽  
pp. 265-272 ◽  
Author(s):  
Abdussalam Elsenousi ◽  
Victor A Aletich ◽  
Ali Alaraj
Keyword(s):  
Arteriovenous Malformations ◽  
Meta Analysis ◽  
Endovascular Embolization ◽  
Complication Rates ◽  
Cure Rate ◽  
Ethylene Vinyl Alcohol ◽  
Neurological Outcomes ◽  
Embolic Agents ◽  
Liquid Embolic ◽  
Cure Rates

BackgroundIn the past decade, preoperative endovascular embolization of cerebral arteriovenous malformations (AVMs) became an essential tool in the treatment of these entities. With the current expansion of technology and wide incorporation of new devices, the indications for the use of endovascular embolization have expanded to include embolization for cure. This has been facilitated by the wide use of the new liquid embolic agents (ethylene-vinyl alcohol co-polymer (EVOH)) in addition to n-butyl cyanoacrylate (NBCA). The aim of this study was to review the current published literature for these two agents and report on permanent neurological injuries and cure rate.MethodsPublished literature citing embolization results for AVMs using liquid embolic agents was reviewed. Papers reporting on permanent complication rates and complete angiographic cure were reviewed. A meta-analysis was performed based on these two variables for the two embolic agents.Results103 studies met the selection criteria. Poor neurological outcomes for NBCA and EVOH were 5.2% and 6.8%, respectively (OR 1.4; p=0.56). AVM complete obliteration rate was seen in 13.7% in the NBCA group and in 24% in the EVOH group (OR 1.9). This OR decreased to 1.35 in the subgroup analysis for patients treated after the year 2000.ConclusionsNBCA continues to have a trend towards lower permanent complication rates, but EVOH had higher angiographic cure rates. The recent literature has demonstrated an increase in the cure rate of AVMs with endovascular embolization techniques yet with a possible increase in permanent neurological deficits and mortality.

Curing arteriovenous malformations using embolization

2014 ◽  
Vol 37 (3) ◽  
pp. E19 ◽  
Author(s):  
Matthew B. Potts ◽  
Daniel W. Zumofen ◽  
Eytan Raz ◽  
Peter K. Nelson ◽  
Howard A. Riina
Keyword(s):  
Arteriovenous Malformations ◽  
Endovascular Embolization ◽  
Cerebral Arteriovenous Malformations ◽  
Curative Intent ◽  
The Past ◽  
Embolic Agents ◽  
Liquid Embolic ◽  
Diagnostic Angiography ◽  
Endovascular Technology

Endovascular embolization is typically reserved as an adjuvant therapy in the management of cerebral arteriovenous malformations (AVMs), either for preoperative devascularization or preradiosurgical volume reduction. Curative embolization plays a limited role in AVM treatment but several studies have shown that it is possible, especially with later-generation liquid embolic agents. Given the complexity of AVM anatomy and the recent controversies over the role of any intervention in AVM management, it is critical that the cerebrovascular community better define the indications of each treatment modality to provide quality AVM management. In this review, the authors evaluate the role of curative AVM embolization. Important considerations in the feasibility of curative AVM embolization include whether it can be performed reliably and safely, and whether it is a durable cure. Studies over the past 20 years have begun to define the anatomical factors that are amenable to complete endovascular occlusion, including size, feeding artery anatomy, AVM morphology, and endovascular accessibility. More recent studies have shown that highly selected patients with AVMs can be treated with curative intent, leading to occlusion rates as high as 100% of such prospectively identified lesions with minimal morbidity. Advances in endovascular technology and techniques that support the efficacy and safety of curative embolization are discussed, as is the importance of superselective diagnostic angiography. Finally, the durability of curative embolization is analyzed. Overall, while still unproven, endovascular embolization has the potential to be a safe, effective, and durable curative treatment for select AVMs, broadening the armamentarium with which one can treat this disease.

scholarly journals Experience of intracranial arteriovenous malformations endovascular treatment with advanced techniques and non-adhesive liquid embolic agents using

2020 ◽  
Vol 33 (3) ◽  
pp. 29-38
Author(s):  
Yu.V. Cherednichenko ◽  
L.A. Dzyak ◽  
E.S. Tsurkalenko
Keyword(s):  
Endovascular Treatment ◽  
Arteriovenous Malformations ◽  
Low Frequency ◽  
Endovascular Embolization ◽  
Average Decrease ◽  
Embolic Agents ◽  
Increased Risk ◽  
Liquid Embolic ◽  
Risk Of Rupture ◽  
Clinically Significant

Objective ‒ to evaluate the possibility of endovascular embolization using non-adhesion of liquid embolic agents as monotherapy for the treatment of cerebral arteriovenous malformations (AVM), its reliability and safety.Materials and methods. examination and gradual endovascular treatment of 64 patients (120 sessions) using non-adhesive liquid embolic agents. Patients were divided into two groups: with ruptured AVM (n = 43) and with unruptured (n = 21). In all cases of unruptured AVM, signs indicating an increased risk of rupture of the AVM were verified.Results. the average decrease in volume after embolization was 79.5 % (up to 50 % ‒ in 7 cases, 50‒75 % ‒ in 14, 75‒99 % ‒ in 29). Complete exclusion of AVM was achieved in 14 (22 %) patients. On average, 2–3 feeders were embolized on the AVM to achieve such results. It was found that the number of feeders was directly proportional to the number of sessions required. Malformations of small size (up to 3 cm) often managed to close in one session. Clinically significant deficiency (2 on the modified Rankin scale) after embolization was found in 2 (3 %) patients. The deficit regressed within 7 days. The angiographic frequency of complete obliteration of AVM at the end of all embolization procedures was 22 % (14 AVM).Conclusions. knowledge of the angioarchitectural characteristics of AVM, which are suitable for the treatment with liquid embolic agents, and their careful selection allow to achieve a high frequency of occlusion with a low frequency of complications. The use of superselective intranidal or perinidal positions of the catheter, slow controlled injections that protect the draining veins, the gradual embolization make the therapy safer.

Modelling of 210Pb behaviour in the catchment and sediment of Lake Tali Karng, Victoria, and estimation of recent sedimentation rates.

1985 ◽  
Vol 36 (1) ◽  
pp. 15 ◽  
Author(s):  
JD Smith ◽  
TF Hamilton
Keyword(s):  
Lake Sediment ◽  
Sediment Core ◽  
Sedimentation Rate ◽  
Average Rate ◽  
210Pb Dating ◽  
Sedimentation Rates ◽  
Depth Profiles ◽  
Unsupported 210Pb ◽  
210Pb Activity ◽  
Over Time

The technique of 210Pb dating of sediments over time scales of up to 120 years is described and illustrated by a study of Lake Tali Karng. Results from the study of a sediment core from the deepest part of the lake shows that the flux of unsupported 210Pb to the sediment is about 145 mBq cm-2 year-1. Over the last 100 years, about 75 cm of sediment has accumulated at an average rate of 150-200 mg cm-2 year-1. Calculations using two models to convert 210Pb activity-depth profiles to age-depth profiles indicate that the sedimentation rate has increased slightly over the last 100 years. It is estimated that about 14% of the 210Pb falling in the catchment reaches the lake sediment, but depending on the assumptions made the possible range is 7-60%.

scholarly journals Meningioma embolization with the pressure cooker technique using Squid 12

2017 ◽  
Vol 23 (4) ◽  
pp. 441-443 ◽  
Author(s):  
Zoltán Szatmáry ◽  
Jan Hillman ◽  
Stephanos Finitsis
Keyword(s):  
Surgical Resection ◽  
Vascular Access ◽  
Vinyl Alcohol ◽  
Arteriovenous Malformations ◽  
Embolic Agent ◽  
Ethyl Vinyl ◽  
Tumor Penetration ◽  
Brain Arteriovenous Malformations ◽  
Embolic Agents ◽  
Liquid Embolic

Background Preoperative meningioma embolization may be performed with microparticles or liquid embolic agents. The pressure cooker technique (PCT) has recently been described for the embolization of brain arteriovenous malformations (AVMs). Case We present the case of a 73-year-old woman with a large frontal interhemispheric meningioma that was successfully preoperatively embolized with the PCT using Squid 12, a new ethyl-vinyl alcohol copolymer embolic agent. The PCT presents considerable advantages relative to conventional embolization techniques such as deeper and faster tumor penetration and embolization of tumors with difficult vascular access, and retrograde feeling of pial afferents may be achieved. Conclusions The use of the PCT with Squid 12 may potentially increase the effectiveness of meningioma embolization, increase tumor devascularization and improve outcomes of surgical resection.

scholarly journals New Treatment Approaches to Arteriovenous Malformations

2017 ◽  
Vol 34 (03) ◽  
pp. 258-271 ◽  
Author(s):  
Patrick Gilbert ◽  
Josée Dubois ◽  
Marie Giroux ◽  
Gilles Soulez
Keyword(s):  
Arteriovenous Malformations ◽  
Poor Response ◽  
High Recurrence Rate ◽  
Reduction Techniques ◽  
Embolic Agents ◽  
Liquid Embolic ◽  
Tailored Approach ◽  
New Treatment ◽  
Surgical Treatments ◽  
Very High

AbstractArteriovenous malformations (AVMs) are high-flow vascular anomalies that have demonstrated a very high recurrence rate after endovascular treatment, surgical treatment, or a combination of both. Surgical treatments have shown good response when they are small and well localized but a poor response when diffuse. A better understanding of the nature of the lesion has led to a better response rate and a safer treatment for these patients. This has been accomplished through a detailed understanding of the angioarchitecture of the lesion, enabling a tailored approach in reaching and targeting the nidus of the AVM with different liquid embolic agents, more specifically ethanol. Flow reduction techniques help in exposing the nidus to sclerosant agents. A clinical classification, the Schobinger classification, will help determine the appropriate time to start or to pursue therapy.

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