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Since 2005, we have used the Ethylene vinyl alcohol copolymers (Onyx 18 and Onyx 34) in the treatment of 29 patients with high flow arteriovenous vascular malformations. There were 20 females and 9 males with ages ranging from 1-67 years (mean 28 years). Nineteen of the malformations involved the extremities and 10 involved the chest, abdominal wall or pelvis. All patients were evaluated with MRI/MRA pre-treatment and ultrasound if necessary to document lesion visibility. Onyx 18 was delivered by subselective transarterial and /or venous microcatheter techniques with or without ultrasound and fluoroscopic guided direct injection under tourniquet control. Tissues from patients whose embolized lesions were subsequently explanted were examined histologically, employing standard Hematoxylin and Eosin staining. Results: Ethylene vinyl alcohol copolymer (Onyx) was found to be durable and effective. Its visibility allowed observation of filling of the malformation interstices. There was minimal post procedure discomfort with Onyx. Of the thirty-nine patients, two developed an area of skin ulceration, and one had worsening of a pre-existing radiation burn. There was one minor complication with migration of a small Onyx fragment to the lung, without sequelae. In patients who received multiple treatments, multiple imaging obliquities were sometimes needed to allow visualization of untreated portions of the lesion. On H & E stains, the filling of the intraluminal spaces of the malformation with associated foreign body type giant cell reaction was observed. Conclusions: Ethylene vinyl alcohol copolymer is a safe, durable agent for treatment of high flow arteriovenous malformations.

One of the most important problems of interstitial thermal therapies of liver metastases is the non-invasive localization and measurement of the coagulated volume. In this study we propose to use three dimensional (3-D) information to evaluate the precision of ultrasound monitoring of thermal tumor therapies under in vivo conditions. For evaluation 3D reconstructions of optical thin slice data of the coagulation volume are compared to 3D-reconstructions of attenuation change ultrasound datasets. The derivation of differential attenuation volumes is demonstrated and the comparison to optical volume measurement is performed. The co registration of both volumes is possible. Motion artefacts can be overcome. The results of 3D ultrasound monitoring of Nd:YAG laser induced (LITT) and radio frequency induced (RFITT) coagulation within in vivo pig liver specimen are presented. The comparison of ultrasonically and optically measured 3D-coagulation volumes show good geometric agreement.

The application of x-ray diagnostics for intraoperative navigation and for registration of hard tissue structures is restrained due to high radiation loads and the not given real time ability. Previous approaches with conventional ultrasonic imaging are only interactively applicable due to the high information content of soft tissue optimised B-mode-images. A pure image processing does not allow an automatic identification of individual structures, so that this must be done by the physician. To decrease the high expense of time, this report presents a concept for an adapted chain of rf-signal processing as well as an ultrasonic system for the contrast-enhanced representation of tissue borders. The system permits an exact measurement of the body geometry, which is demonstrated by determining the position of the pelvis entry plane.

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