Three-Dimensional, computer simulated navigation in endoscopic neurosurgery

Abstract

Background: In order to address the pre- and perioperative need for visualization and prediction of patient-specific anatomy for surgical planning, endoscopic neurosurgeons have increasingly relied on computerized navigation devices to guide their surgical approaches.

Objective: This manuscript aims to review: 1) the use of neuronavigation in endoscopic neurosurgery for pre-operative planning, 2) the intraoperative advantages of neuronavigation in endoscopic neurosurgery, and 3) the effects of navigation guidance on operative time, registration accuracy, brain shift, and avoidance of complications. Limitations of the current neuroendoscopic navigation literature will be discussed.

Methods: We conducted a search using PubMed-MEDLINE; the keywords "stereotactic navigation AND endoscopic surgery" and "simulation AND endoscopic neurosurgery". 36 studies were identified that addressed the use of neuronavigation in endoscopic neurosurgery. These studies were then further analyzed for topics relevant to computerized neuroendoscopy and reviewed for the purposes of this article.

Conclusion: Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to < 1-2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

Keywords: Endoscopic; frameless; image-guided; neuronavigation; stereotactic navigation.

Figure 1. Pre-operative MRI of the brain and cervical spine

(A) Pre-operative sagittal and axial T2-weighted magnetic resonance imaging scans demonstrating a Type I Chiari Malformation with associated basilar invagination. (B) There is ventral and dorsal medullary compression by the odontoid process and cerebellar tonsils, respectively.

Figure 2. 3D-reconstructed pre-operative images displayed by the Surgical Theatre™ planning station (Surgical Theatre, LLC, Mayfield Village, OH)

(A) (blue asterix) A tortuous left internal carotid artery is seen directly anterior to the C2 vertebral body and odontoid process. (B) A stereotactic registration wand was used to plan the surgical approach (maroon asterix). Based on this imaging, a trans-nasal approach was selected given the location of the left internal carotid artery.

Figure 3. Pre-operative surgical planning using 3D reconstructions rendered by Surgical Theatre™ (Surgical Theatre, LLC, Mayfield Village, OH)

(A) In this coronal view, the vertebrobasilar junction is seen in relation to the clivus (blue asterix). (B) In this sagittal view, multiple trans-nasal trajectories are projected. The final intraoperative trajectory is displayed (red arrow).

Figure 4. 3D-reconstructed coronal view demonstrating a “probe’s eye” view through the nasal septum

The anterior face of C1-2 is seen in the center of the circle (blue asterix).

Figure 5. Comparison of pre-operative trajectory planning and resultant post-operative decompression

(A) Sagittal T1-weighted MRI demonstrating the surgical approach (endoscopic trans-nasal, red arrow). (B) Post-operative T1-weighted MRI demonstrating resection of anterior arch of C1 and odontoid process (blue asterix). There is less ventral compression of the medulla and craniocervical junction. (C) Post-operative midline sagittal CT scan demonstrating resection of the anterior and posterior arch of C1 and the odontoid process (blue asterix). (D) Coronal CT view demonstrating satisfactory resection of the odontoid tip (blue asterix).

Figure 6. Post-operative lateral flexion-extension cervical x-rays

Post-operative lateral flexion-extension cervical x-rays after occiput-C4 instrumentation and fusion demonstrating dynamic stability and preservation of cervical lordosis.