gms | German Medical Science

Objective: Imaging of anatomical microstructures with optical coherence tomography (OCT) proves to correlate with histological findings. The present work summarises the possibilities and limits of three-dimensional microscope integrated OCT as a suitable intraoperative imaging modality during microsurgical procedures.

Methods: We performed OCT-Scans during supratentorial micro-neurosurgical procedures with a microscope-integrated OCT camera. Using a standardized protocol, the scans were post-processed with ImageJ2 and Fiji. The surgeon defined the region of interest depended on surgical approach, target and conditions. All patients gave written informed consent and the local ethics committee approved the study.

Results: Scans of the dura mater (n=20), the gyral and sulcal subarachoid space (n=26), arteries (n=10) and veins (n=6) of the anterior circulation and unruptured aneurysms of the anterior circulation (n=16) and their parent vessels were generated. OCT allowed depicting, identifying and measuring the anatomical microstructure of the dura mater, the subarachnoid space and the vessel wall of arteries and veins in most cases. The scans of aneurysms identified the transition zone of the aneurysm neck from the physiological 3-layer structure of the parent vessel to the thin mono-layer of the aneurysm wall. Furthermore, irregularities of both aneurysm and parent vessel wall such as calcification, residual tunica media and atherosclerotic plaque could be visualized.

Conclusion: OCT allows in-vivo imaging especially of those structures, vulnerable to artefacts during histopathological slide preparation (e.g. subdural and subarachnoid space, vessel wall) with high image quality, approaching the spatial resolution of histopathology. Additional information of vessel and aneurysm wall structure might be of relevance during intraoperative manipulation and clip positioning.