Background: Hyperspectral imaging (HSI) is an advanced, wide-field optical imaging technique
that enables the detection of light reflectance as multiple, narrow wavelength bands
as opposed to the conventional three red, green, and blue (RGB) broad wavelength bands
seen with the naked eye. When applied to biological tissue, the refined spectral information
from HSI permits real-time extraction of biological and physiological parameters,
one of which is tissue oxygenation (StO2). Intraoperative stroke occurs in up to 6.4% of cranial neurosurgical procedures,
and thus early detection of intra-operative ischemia may prove key to improving patient
outcomes. Here we describe a case series in which a novel HSI system has been deployed
in neurovascular surgery, demonstrating real-time change in StO2.
Methods: A snapshot mosaic HSI camera was coupled to a Zeiss Kinevo-900 ([Fig. 1]) and connected to a dedicated camera control unit. Using software developed by Hypervision
Surgical Ltd, real-time HSI video recordings were acquired during eight aneurysm surgeries
and eight arteriovenous malformation (AVM) extirpations. From these recordings, spectral
tissue information, including StO2, was extracted from surgeon-annotated regions of
interest (RoI). The operating room team completed questionnaires designed based on
the System Engineering Initiative for Patient Safety (SEIPS) framework, along with
semi-structured interviews after each case to assess how well the HSI system integrates
into the neurosurgical theater workflow.
Results: Using our system, real-time HSI recordings were successfully and safely acquired
during all 16 cases. In one middle cerebral artery (MCA) aneurysm clipping, our HSI
detected a decrease in StO2 over a region of cortex 8 minutes before electrophysiological
change was demonstrated. In a second procedure, resection of a giant, distal posterior
inferior cerebellar artery (PICA) aneurysm ([Fig. 2]) and anastomosis, our system detected ischemia within the medulla ([Fig. 3]) and clear reperfusion once flow was re-established ([Fig. 4]). Feedback from all operating room team members was positive, demonstrating minimal
disruption to the standard neurosurgical workflow.
Conclusion: Our intra-operative HSI system integrated seamlessly into the neurosurgical workflow
while demonstrating the capability to provide enhanced tissue information to the surgeon
in real time. Not only did tissue oxygenation correlate with electrophysiological
changes, but it also demonstrated ischemia before these changes were detected, paving
the way for earlier intra-operative surgical decision-making and safer surgery in
the future.
