Reliability of neuronavigation-assisted trans-sphenoidal tumor resections

Objective: To analyse the surgical reliability of neuronavigation-assisted trans-sphenoidal tumor resections. Method: In the past 7 years, all patients, who underwent neuronavigation-assisted trans-sphenoidal tumor resection in our department, were additionally intraoperatively controlled with a radioscopic device. Tumor removal was repeatedly checked up with the navigator and the tip of the pointer was correlated with the lateral intraoperative skull radiologic examination to confirm the real pointer deepness, spatial location and trajectory. The reliability of these assessments was analysed by simple images comparison and searching for tumor-related differences, and controlled with post-operative magnetic resonance studies. Results: During the analysed period, a total of 36 patients were treated in our department. Diagnosis included 14 non-secreting adenomas, 18 secreting adenomas and four non-pituitary tumors. Tumors diameter ranged from 1.4 to 4.5 cm. A mean accuracy of 0.8 mm could be achieved for all patients. In all cases, the real deepness, position and trajectory of the navigator were identical to those observed with X-ray examinations. At least nine from ten pointer determinations were identical in all cases. Particularly, all pituitary tumors with suprasellar extension could be safely controlled, even during advanced stages of resection and before the tumor capsule detached from suprasellar neighbor structures. Intrasellar, clival and suprasellar tumors were adequately removed as confirmed with MRI. Conclusions: Radioscopic controlled neuronavigation shows high reliability and allows surgeons to be more confident during the trans-sphenoidal resection of skull base tumors. This offers the advantage to reduce the patient's X-ray exposure and the possibility of simultaneous multiplanar images evaluation.