PMON155 Intraoperative, confocal laser endomicroscopy in pituitary surgery

Abstract

Abstract Introduction Fluorescence imaging, such as confocal laser endomicroscopy (CLE) is a fast modality of image acquisition, which offers the possibility of early intraoperatively diagnosis and may be used to improve surgical decision making. Objective Within a 3-month prospective trail we used the Zeiss CONVIVO CLE in transspehnoidal surgery for different sellar pathologies. CLE is a miniaturized portable, handheld, fiber optic-based, confocal laser scanning microscope used in conjunction with a 488-nm excitable fluorophore. During the trial period we investigated feasibility, diagnostic accuracy and usability in terms of differential diagnosis in transsphenoidal surgeries of various pituitary tumours (15 pituitary adenomas, 2 craniopharyngiomas, 1 sellar metastasis). Method: Patients were randomly selected. Inclusion criteria were a pituitary macroadenoma or a sellar mass lesion exceeding 10 mm in diameter. A transsphenoidal approach was used and fluorescin was injected upon opening the sellar floor. CLE was carried out immediately after dural opening and during tumour resection, whenever possible. Additionally, the microprobe was used ex vivo with the resected tumor material. Histopathologic features of CLE images and H&E-stained permanent sections were assessed and compared postoperatively. Result: We were able to obtain CLE in-vivo images in all cases. Using the microscopic approach, no problems occurred regarding space for the microprobe. To obtain in-vivo images we had to rest the probe within a mount. Wiggling of the surgeon's hand, pulse synchronous movements of the mass and mild intraoperative venous bleeding led to inexact images. To overcome these problems, we used CLE as early as possible at the beginning of tumor resection to avoid bleeding interferences. Additionally we investigated resected tumor specimens ex-vivo within the OR. Since no bleeding and no interference with movements occurred image quality and acquisition time improved. Histopathologic features of CLE images and H&E-stained permanent sections showed, that except for the sellar metastasis, a diagnosis could be made on the basis of the intraoperative CLE images, whereas the ex-vivo images were more precise. Conclusion CLE is a potential imaging modality for transnasal assessment of skull base and pituitary lesions. It may help to establish an early diagnosis, to identify pituitary microadenomas, especially in cushing´s disease and to distinguish the various sellar pathologies. CLE is a fascinating possibility to verify a suspected diagnoses already intraoperatively. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.