Mizuho Minimally Invasive Brain Tumor Surgery Award - Application of Confocal Laser Endomicroscopy in Endonasal Resection of Brain Lesions

Introduction: Confocal Laser Endomicroscopy (CLE) has been used successfully in open neurosurgical tumor resections to provide real-time microscopic visualization and differentiation of tissue types. Expanding the use of CLE to endonasal resections offers a novel approach that could enhance surgical precision and improve diagnostic accuracy in minimally invasive settings. This study assesses CLE’s efficacy in differentiating lesions intraoperatively within the confines of an endonasal approach, comparing real-time imaging results and intraoperative diagnoses with final histopathologic diagnoses. Integrating CLE into endonasal procedures may offer a valuable tool for optimizing outcomes in complex, limited-access surgeries.

Methods: In a prospective trial, 10 adult patients undergoing endonasal resections or biopsies were imaged intraoperatively using confocal laser endomicroscopy (CONVIVO). Inclusion criteria encompassed a range of intracranial and sellar region pathologies, including suspected gliomas, meningiomas, pituitary adenomas, and other hormone-secreting tumors affecting brain function or structure who were surgical candidates and provided informed consent. Sodium fluorescein was administered prior to imaging to enhance visualization, and intraoperative CLE data were collected. Importantly, no intraoperative decisions were made based on interpretation of CLE images. The primary outcome evaluated was the degree of concordance between intraoperative CLE findings and final histopathologic diagnosis.

Results: In this cohort of 10 patients, intraoperative CLE demonstrated a 95% concordance rate with final histopathologic diagnoses. CLE provided cellular-level imaging of biopsied areas and enabled visualization of tumor margins that were not resected, supporting real-time assessment of lesion boundaries. Although no intraoperative adjustments were made based on CLE findings, the feasibility of using CLE for real-time procedural guidance was demonstrated. No complications or adverse events related to CLE use were observed.

Conclusion : This case series within a clinical trial highlights the potential of CLE to enhance intraoperative imaging in endonasal neurosurgical procedures. CLE demonstrated high concordance with histopathologic diagnoses and provided valuable real-time visualization of lesion margins. These findings support CLE’s potential as a tool for improving diagnostic accuracy and surgical precision in minimally invasive neurosurgery, warranting further exploration in larger studies.