First experience with augmented reality neuronavigation in endoscopic assisted midline skull base pathologies in children

Abstract

Introduction: Endoscopic skull base approaches are broadly used in modern neurosurgery. The support of neuronavigation can help to effectively target the lesion avoiding complications. In children, endoscopic-assisted skull base surgery in combination with navigation systems becomes even more important because of the morphological variability and rare diseases affecting the sellar and parasellar regions. This paper aims to analyze our first experience on augmented reality navigation in endoscopic skull base surgery in a pediatric case series.

Patients and methods: A retrospective review identified seventeen endoscopic-assisted endonasal or transoral procedures performed in an interdisciplinary setting in a period between October 2011 and May 2020. In all the cases, the surgical target was a lesion in the sellar or parasellar region. Clinical conditions, MRI appearance, intraoperative conditions, postoperative MRI, possible complications, and outcomes were analyzed.

Results: The mean age of our patients was 14.5 ± 2.4 years. The diagnosis varied, but craniopharyngiomas (31.2%) were mostly represented. AR navigation was experienced to be very helpful for effectively targeting the lesion and defining the intraoperative extension of the pathology. In 65% of the oncologic cases, a radical removal was proven in postoperative MRI. The mean follow-up was 89 ± 79 months. There were no deaths in our series. No long-term complications were registered; two cerebrospinal fluid (CSF) fistulas and a secondary abscess required further surgery.

Conclusion: The implementation of augmented reality to endoscopic-assisted neuronavigated procedures within the skull base was feasible and did provide relevant information directly in the endoscopic field of view and was experienced to be useful in the pediatric cases, where anatomical variability and rarity of the pathologies make surgery more challenging.

Keywords: Endoscopic assisted endonasal approach; Neuroendoscopy; Neuronavigation; Sellar region.

Fig. 1

Hybrid registration procedure of the patients head before surgery capturing anatomical landmarks and multiple random points on the surface of the nose, the forehead and the anterior calvarium (left upper and middle pictures). The registration of the endoscope includes two steps using a registration matrix in which the length of the endoscope was defined and the visual field was registered at a specific magnification and camera orientation using a predefined matrix pattern (right upper, middle and lower pictures). In the intraoperative setting both, the endoscope’s and neuronavigation screen could be appreciated in parallel. The endoscopic views on the navigation screen incorporates the AR information together with the reconstructed 3D MRI sections along the endoscopes orientation (left lower picture)

Fig. 2

Case example of a patient with a Rathke cleft cyst: upper row: preoperative MRI (T2 sagittal and T1 post-gadolinium coronal sequence). Middle row: intraoperative endoscopic view with AR information indicating the trajectory (multiple rings), the target (blue contour) and the carotid arteries. Lower row: postoperative MRI (T2 sagittal and T1 post-gadolinium coronal sequences)

Fig. 3

Case example of a patient with a craniopharyngioma: Upper row: preoperative MRI (T1 sagittal and coronal post-gadolinium sequences). Middle row: intraoperative endoscopic view at different anatomic levels of the turbinates, the sphenoid cavity and the sella with AR information indicating the carotid arteries. Lower row: postoperative MRI (T1 sagittal and coronal post-gadolinium sequences)