Classic Versus Ultrasound Navigation in the Surgery of High Grade Gliomas

Introduction: Despite the major progress made in neurosurgery during the last decades, the high grade gliomas (HGGs) remain one of the entities with poorest prognosis and disappointing surgical results. Of the factors generally associated with better prognosis, only the extent of resection at the first surgery is within neurosurgeon’s control. Aim: A comparison has been made between a group of HGG patients that underwent image-guided surgery with preoperative imaging only (“classic” neuronavigation) and a second group, operated under intraoperative ultrasound (US) navigation guidance. Material and Methods: For a 6 years period 75 patients diagnosed with HGGs underwent surgery guided by intraoperative US-navigation. Another 71 HGG patients were operated on by using “classic” navigation, based on preoperative images. Two neuronavigation systems - Vector Vision 2 and Sonowand Invite were used during surgery, the latter allowing for intraoperative ultrasound images to be navigated. In three of the patients of the US-group, Fluorescein sodium (20 mg/kg i.v.) was used to better visualize the tumor borders during the resection. Results: Gross-total resection was achieved in 32(42.7%) and near-total in another 32(42.7%) cases in the group with US-navigation, compared with 22(31.0%) and 26(36.6%) in the “classic” navigation group respectively. Slightly lower complication rates (17.3% versus 18.3%) were registered in the US-group. In the three surgeries performed with combined Fluorescein and US-navigation guidance, a good congruence between the ultrasound and the dye-defined tumor borders was observed. Conclusion: The results of our study suggest that the use of ultrasound neuronavigation could facilitate the surgery of HGGs by helping to achieve greater extent of resection without increasing the complication rates. The quality of the US guidance seems to be comparable to that of the Fluorescein for depiction of the tumor boundaries.