Endoscopic Assistance in the Deep and Narrow Spaces of the Brain—Microscopic Tumor Surgery Supported by the New Micro-Inspection Tool QEVO® (Technical Note)

Abstract

Introduction: To evaluate the feasibility and efficacy of the innovative micro-inspection tool QEVO® (Carl Zeiss Meditec, Oberkochen, Germany) as an endoscopic adjunct to microscopes for better visualization of the surgical field in complex deep-seated intracranial tumors in infants and adults.Materials and Methods: We retrospectively assessed the surgical videos of 25 consecutive patients with 26 complex intracranial lesions (time frame 2018–2020). Lesions were classified according to their anatomical area: 1 = sellar region (n = 6), 2 = intra-ventricular (except IV.ventricle, n = 9), 3 = IV.ventricle and rhomboid fossa (n = 4), and 4 = cerebellopontine angle (CPA) and foramen magnum (n = 7). Indications to use the QEVO® tool were divided into five “QEVO® categories”: A = target localization, B = tailoring of the approach, C = looking beyond the lesion, D = resection control, and E = inspection of remote areas.Results: Overall, the most frequent indications for using the QEVO® tool were categories D (n = 19), C (n = 17), and E (n = 16). QEVO® categories B (n = 8) and A (n = 5) were mainly applied to intra-ventricular procedures (anatomical area 2).Discussion: The new micro-inspection tool QEVO® is a powerful endoscopic device to support the comprehensive visualization of complex intracranial lesions and thus instantly increases intraoperative morphological understanding. However, its use is restricted to the specific properties of the respective anatomical area.

Technical Assessment of Microvascular Decompression for Trigeminal Neuralgia Using a 3-Dimensional Exoscope: A Case Series

“…The key for a successful MVD is a clear anatomic visualization of cerebrovascular structures in the depth of the cerebellopontine angle. Although microscopic, endoscopic, and endoscopic-assisted techniques have been used to accomplish this goal, [3][4][5][6][7]14,15 all have individual limitations. The OM has been used since 1964 and remains the most commonly used approach by neurosurgeons when performing a retrosigmoid procedure.…”

“…Some OM now offer integrated endoscopic control, which can be advantageous if the trigeminal nerve root cannot be sufficiently inspected over the viewing angle of the OM alone. 5 Neurosurgeons feel confident with the periscope-like build of the OM, facing into the operating area. Nevertheless, despite the improved comfort in using the microscope, the technology itself remains poorly evolved, typically resulting in poor ergonomics and a cumbersome MVD surgery because (1) surgeons need to change the viewing angle to a high degree when performing the retrosigmoid approach in the prone, supine, or lateral position; (2) surgeons experience a large distance from the eyepiece to the objective of the OM with the need to extend the arms, which often leads to early fatigue during the sitting position; and (3) surgeons experience insufficient illumination in the depth, one of the main advantages in using the exoscope over the OM.…”

“…Endoscopes were subsequently introduced either as an endoscopy-assisted procedure or as the endoscope fully replacing the OM to enhance the visualization in the cerebellopontine angle. [3][4][5][6][7] The use of exoscopes is currently evolving in the field of neurosurgery with the development of 3-dimensional (3D) visualization techniques. An increasing number of neurosurgeons are starting to use these novel visualization tools, and it remains to be verified if such tools have the potential to replace the conventional OM to perform various standard procedures.…”

“…Endoscopes were subsequently introduced either as an endoscopy-assisted procedure or as the endoscope fully replacing the OM to enhance the visualization in the cerebellopontine angle. 3-7…”