Intraoperative real-time contrast-enhanced ultrasound angiography: a new adjunct in the surgical treatment of arteriovenous malformations

Object The goal of this study was to combine the use of ultrasound contrast agents with intraoperative ultrasound techniques to identify intraoperatively a patient's vascular anatomy, including feeding arteries and draining veins of an intracranial arteriovenous malformation (AVM). Methods The authors examined 12 consecutive patients with AVMs that had been diagnosed on the basis of preoperative findings on magnetic resonance images and digital subtraction angiograms obtained between September 2003 and December 2005. After each patient had undergone a routine craniotomy, a bolus of contrast agent was injected intravenously, and a real-time microbubble perfusion process was observed to identify the feeding arteries and draining veins of the AVM in a single cross-section. The so-called burst–refill technique was used to sweep the lesion in multiple sections and orientations to obtain information on the surrounding vascular anatomy, after which the findings were compared with those obtained during preoperative imaging. Results Intraoperative ultrasonography provided high-quality images in every case. Although plain imaging failed to show an identifiable AVM boundary, color Doppler flow imaging clearly delineated the shape and margin of the AVM. Nevertheless, neither mode of imaging enabled the surgeons to categorically distinguish between feeding and draining vessels. The real-time perfusion process of microbubbles was first visualized 20 to 30 seconds after the SonoVue bolus injection, and the burst–refill technique made possible identification of the vascular anatomy of malformation lesions in multiple planes. Conclusions Using both an ultrasound contrast agent and the burst–refill technique provided a rapid, convenient, and precise way of locating AVM feeding arteries intraoperatively. The combined technique seems warranted in the intraoperative treatment of AVMs.