Basics and Principles in the Application of Onyx LD Liquid Embolic System in the Endovascular Treatment of Cerebral Arteriovenous Malformations

Abstract

solution consisting of the embolic component and the tantalum powder. The microcatheter is flushed with saline and subsequently after the dead space volume is filled with 0.23 to 0.26 ml of pure DMSO depending on witch catheter is deployed (Ultraflow TM or Marathon TM , Micro Therapeutics, Inc., Irvine, CA). It is important to follow these steps very carefully in order to avoid unintentional precipitation of Onyx, which immediately begins when there is contact to water, saline solution or blood. Therefore, the catheter hub requires to be flushed with DMSO also. After the air-bubble-free aspiration of the Onyx in a dedicated syringe, the syringe is connected to the microcatheter producing a clear interface between Onyx and DMSO by positioning the syringe vertically immediately after the connection or, more simply, by using a special Interface-Adapter. Application of Onyx LD in central AVMs The most important factor for successful embolization of cerebral or spinal AVMs is the intranidal positioning of the microcatheter (figure 1). Beside clinical experiences experimental data using a hydraulic pump model or the rete mirabile 14 of the swine also clearly demonstrat-Preparation of Onyx liquid embolic system The ready-to-use vials of Onyx LD (1,5 ml) are placed on a mixer and have to be shaken for at least 20 minutes to obtain a homogenous

Preoperative Embolization of Intracranial Arteriovenous Malformations With Onyx

“…Initial experiences using the Onyx system in the endovascular treatment of cerebral AVMs has been reported in single and multicenter studies (17,18,(28)(29)(30)(31)38). The results are promising, including achievement of long-duration injections (29) and improved angiographic outcomes (28).…”

“…The positioning of the microcatheter, ideally intranidal or close to the nidus, is an important factor in a successful embolization (30). The type of Onyx solution used depends on the distance from the microcatheter tip to the venous part of the AVM, the flow conditions, and the shunt type (plexiform, fistulous, or mixed).…”

Transarterial embolization of the external carotid artery in the treatment of life-threatening haemorrhage following blunt maxillofacial trauma

“…30 There are several drawbacks to this EA, including long pre-injection preparation time (20 minutes of mixer shaking are required to achieve homogenization), a self-hiding effect when used in larger amounts due to high radiopacity, plenty of artefacts in a postinterventional imaging, and the potential to combust or produce sparks during monopolar surgical cauterization. 31,32 In addition, Onyx's dark colour may result in a black discoloration of the skin after superficial embolization or subcutaneous extravasation of the EA. 33,34 Precipitating hydrophobic injectable liquid (PHIL) (MicroVention, Tustin, CA, USA) is a non-EVOH copolymer-based non-adhesive liquid EA suspended in DMSO with iodine covalently bonded to copolymer to provide radiopacity.…”

Combined staged therapy of complex arteriovenous malformations: initial experience

“…Onyx preparation and injection technique have been well described by other authors (6)(7)(8)(9)(10). From that moment on, endovascular therapy is always performed by two senior interventional radiologists (Lopez-Ibor L and Gil A) in a room provided with a last generation biplane angiography system.…”

“…Last generation angiography systems also allow image fusion (computed tomography, MRI, 3D angiography) what may be helpful regarding the surgical procedure planning. Onyx preparation and injection technique have been well described by other authors (6)(7)(8)(9)(10). The material is contraindicated in preterm and very low birth weight newborns (<1500 g) and in patients suffering from hepatic failure.…”