Intraoperative ultrasound assistance in resection of intracranial meningiomas

Objective： Intracranial meningiomas, especially those located at anterior and middle skull base, are difficult to be completely resected due to their complicated anatomy structures and adjacent vessels. It＇s essential to locate the tumor and its vessels precisely during operation to reduce the risk of neurological deficits. The purpose of this study was to evaluate intraoperative ultrasonography in displaying intracranial meningioma and its surrounding arteries, and evaluate its potential to improve surgical precision and minimize surgical trauma. Methods： Between December 2011 and January 2013, 20 patients with anterior and middle skull base meningioma underwent surgery with the assistance of intraoperative ultrasonography in the Neurosurgery Department of Shanghai Huashan Hospital. There were 7 male and 13 female patients, aged from 31 to 66 years old. Their sonographic features were analyzed and the advantages of intraoperative ultrasonography were discussed. Results： The border of the rneningioma and its adjacent vessels could be exhibited on intraoperative ultrasonography. The sonographic visualization allowed the neurosurgeon to choose an appropriate approach before the operation. In addition, intraoperative ultrasonography could inform neurosurgeons about the location of the tumor, its relation to the surrounding arteries during the operation, thus these essential arteries could be protected carefully. Conclusions： Intraoperative ultrasonography is a useful intraoperative technique. When appropriately applied to assist surgical procedures for intracranial meningioma, it could offer very important intraoperative information （such as the tumor supplying vessels） that helps to improve surgical resection and therefore might reduce the postoperative morbidity.

Preoperative surgical planning for intracranial meningioma resection by virtual reality

Background The Dextroscope system by Volume Interactions （Singapore） had been applied to minimally invasive neurosurgery in many units. This system enables the neurosurgeon to interact intuitively with the three-dimensional graphics in a direct manner resembling the way one communicates with the real objects. In the paper, we explored its values in pre-operation surgical planning for intracranial meningiomas resection. Methods Brain computed tomography （CT）, magnetic resonance imaging （MRI）, and magnetic resonance venography （MRV） were performed on 10 patients with parasagittal and falcine meningiomas located on central groove area; brain CT, MRI and magnetic resonance angiography （MIRA） were performed on 10 patients with anterior skull base meningiomas and 10 patients with sphenoid ridge meningiomas. All these data were transferred to Dextroscope virtual reality system, and reconstructed. Then meningiomas, skull base, brain tissue, drainage vein and cerebral arteries were displayed within the system, and their anatomic relationships were evaluated. Also, the simulation operations were performed. Results For parasagittal and falcine meningiomas, the relationships of tumor with drainage vein and superior sagittal sinus were clearly displayed in the Dextroscope system. For anterior skull base and sphenoid ridge meningiomas, the relationships of tumor with bilateral internal carotid arteries, anterior cerebral arteries, middle cerebral arteries and skull base were vividly displayed within the virtual reality system. Surgical planning and simulation operation of all cases were performed as well. The real operations of all patients were conducted according to the simulation with well outcomes. Conclusions According to the virtual reality planning, neurosurgeons could get more anatomic information about meningioma and its surrounding structures, especially important vessels, and choose the best approach for tumor resection, which would lead to better prognosis for patients.