Onyx®, A New Tool for Intraoperative Localization of Liver Lesions.

Background: Precise preoperative localization of liver tumors facilitates successful surgical procedures, Intraoperative ultrasonography is a sensitive imaging modality. However, the presence of small non-palpable isoechoic intraparenchymal lesions may be challenging intraoperatively.

Methodology and material description: Onyx® is a non-adhesive liquid agent comprised of ethylene-vinyl alcohol usually used dissolved in dimethyl-sulfoxide and suspended micronized tantalum powder to provide contrast for visualization under fluoroscopy and ultrasonography and a macroscopic black shape. This embolization material has been increasingly used for the embolization of intracranial arteriovenous malformations. We present the novel application of Onyx® on liver surgery.

Current status: We present the case of a female, 55 years-old, whose medical history revealed an elective sigmoidectomy (pT3N1a). After 17 months of follow up, by PET-CT scan, the patient was diagnosed of a small intraparenchymal hypo-attenuated 13 mm tumor located at segment V consistent with metachronous colorectal liver metastasis. Open metastasectomy was performed, ultrasonography-guided Onyx® infusion was delivered the day after, intraoperative ultrasonography showed a palpable hyperechoic material with a posterior acoustic shadowing artifact around the lesion. Onyx® is a promising new tool, without any previous application on liver surgery, feasible with advantages in small not palpable intraparenchymal liver lesions.