gms | German Medical Science

Objective: The appropriate extent of resection and especially the intraoperative distinction between normal and abnormal tissue leads to a successful tumour resection. Considering its benefits in gastroenterology or pulmonology, our goal is to establish confocal endomicroscopy in neurosurgery, providing a new method of real time imaging of intraoperative findings.

Method: We investigated tissue specimens of 82 patients (Glioblastoma 25; Meningeoma 23 Pituitary adenoma 4, Metastasis 7, Schwannoma 5, Paraganglioma 1, Ependymoma 1, Astrocytoma 2, AVM 1, Gliosarcoma 1, Colloid cyst 1, Neuroblastom 1, Cavernoma 2, Oligodendroglioma 1, Lymphoma 2, Plexuspapilloma 1, Neurinoma 1, ICH 1, Hemangioblastoma 1, Astroblastoma 1) by confocal laser endomicroscope (EndoMAG 1, KARL Storz GmbH). Histomorphologic criteria were established in order to make a diagnose equivalent to neuropathologist findings. Fresh tumour specimens were acquired from our neurosurgical department after processing by the Institute of Pathology. These were then examined under the endomicroscope, first in their native state, then after being stained with methylene blue. Additionally, pig brains were investigated to analyze healthy tissue. Primary cell cultures of all resected tumours were cultivated and investigated as well, before and after staining with methylene blue, to give an impression of the cellular structures themselves.

Results: Even though the acquired images were not entirely comparable to histology slices, we found a difference in structure of the investigated entities and therefore, we were able to establish criteria of returning patterns. These included the morphology of the nucleus and its location within the cell, existence and shape of cytoplasm, existence of psammoma bodies, cell contact and density, diffuse growth pattern and the existence of blood vessels.

Conclusions: Our findings provided a guide to using confocal laser endomicroscopy in Neurosurgery, which will eventually become a complementary tool to instantaneous sections and help to improve the surgical quality through the extent of resection.