Integration of the Zeiss QEVO® Inspection Tool in a Commercial Retractor System for Bimanual Angled View Tumor Resections: Technical Note With Case Illustration

BACKGROUND AND OBJECTIVES: The QEVO® microinspection tool integrated into the ZEISS KINEVO® platform provides high-quality angled visualization and is increasingly used to inspect microscopic blind spots during neurosurgical tumor resections. However, effective integration of the QEVO® tool into the standard neurosurgical bimanual workflow remains challenging in delicate environments, as no commercially available device can securely position the tool to enable undisturbed bimanual dissection under angulated endoscopic vision. This report describes a practical and reproducible technique for stable hands-free fixation of the QEVO® inspection tool using a commercially available retractor system, enabling bimanual microsurgical dissection under angled endoscopic visualization. METHODS: The QEVO® tool was integrated into the DORO LUNA® retractor system using COBRA® flexible rotary arms and a Mini Vice adaptor. The setup was applied in 15 pediatric brain tumor surgeries between March 2024 and June 2025. Four representative cases, including pineal region tumor, craniopharyngioma, and cerebellopontine angle ependymomas, illustrate technical nuances, operative positioning, and workflow. Intraoperative microscopic and endoscopic images document transitions between visualization modalities and bimanual resection under angled view. RESULTS: The retractor-mounted QEVO® provided stable, hands-free angled visualization in all cases, regardless of patient positioning, enabling uninterrupted bimanual resection beyond the direct microscopic line of sight. No device-related complications or thermal injuries were observed. The technique facilitated maximal safe resection in confined regions adjacent to critical neurovascular structures. CONCLUSION: This approach addresses limitations of angled view-assisted microsurgery with the QEVO® tool, offering enhanced control in demanding procedures and enabling higher surgical radicality with reduced operative risk.