Intranidal

Intranidal Embolization with Nonadhesive Liquid Embolic Agents ( Modified by Prof. I. Wanke) 104... 

As outlined by Houdart et al. (1993), the depiction of intranidal aneurysms is difficult it is often performed at the time of superselective angiography. Moreover, true arterial intranidal aneurysms have to be distinguished from pseudoaneurysms, which are at the point of rupture of the nidus or of the venous drainage. 

Thus, we can postulate with Berenstein and Lasjaunias (1992) that intranidal aneurysms represent a weakness of the angioarchitecture and should influence treatment strategy. This is prohahly also true for other associated aneurysms. 

The technique of intranidal embolization with Histoacryl requires tremendous experience on the part of the operator, because the injection is fast (from a few seconds to 1-2 min) and clinical consequences or improper gluing are disastrous. 

In some instances, complete cure is deemed impossible despite a combined technique. Partial treatment can yet be indicated in some cases (a) to cure a weak point of the AVM such as a false aneurysm, intranidal aneurysms, or large feeding artery aneurysms (Fig. 3.6) (b) to improve the clinical symptoms in case of a large AVM presenting with progressive neurologic deficits (Fox 1997). 

Onyx as non-adhesive liquid embolic has now become a widely used material to treat AV-malfor-mations and also pial and dural AV-fistulas. With knowledge of the morphologic characteristics of AVMs that are suitable for a treatment with Onyx, high occlusion rates and low complication rates in treating a small number of feeders are feasible. Su-perselective intranidal or perinidal catheter positions and slow, controlled injections that protect the draining veins make the therapy safe even in complex AVMs and critical locations. Complete oblit-... 

The major advantage to the use of Onyx compared with cyanoacrylates is the ease of injection. The catheter should be placed in the same wedge situation as for intranidal glue injection. The injection should be very slow, as well. It may be stopped for... 

Partially targeted treatment (embolization) to eliminate risk factors of hleeding/rehleeding (feeding artery aneurysms, intranidal aneurysms, false aneurysms)... 

Marks MP, Lane B, Steinberg GK et al. (1992) Intranidal aneurysms in cerebral arteriovenous malformations evaluation and endovascular treatment. Radiology 183 355-360... 

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