Abstract
Significance: Near-infrared (NIR) fluorescence imaging using indocyanine green (ICG) has
proven to be a feasible application for real-time intraoperative assessment of tissue perfusion,
although quantification of NIR fluorescence signals is pivotal for standardized assessment of
tissue perfusion.
Aim: Four patients are described with possible compromised bowel perfusion after mesenteric
resection. Based on these patients we want to emphasize the difficulties in the quantification of
NIR fluorescence imaging for perfusion analysis.
Approach: During image-guided fluorescence assessment, 5 mg of ICG (2.5 mg∕ml) was intravenously
administered by the anesthesiologist. NIR fluorescence imaging was done with the
open camera system of Quest Medical Imaging. Fluorescence data taken from the regions of
interest (bowel at risk, transition zone of bowel at risk and adjacent normally perfused bowel,
and normally perfused reference bowel) were quantitatively analyzed after surgery for fluorescence
intensity-and perfusion time-related parameters.
Results: Bowel perfusion, as assessed clinically by independent surgeons based on NIR fluorescence
imaging, resulted in different treatment strategies, three with excellent clinical outcome,
but one with a perfusion related complication. Post-surgery quantitative analysis of fluorescence
dynamics showed different patterns in the affected bowel segment compared to the unaffected
reference segments for the four patients.
Conclusions: Similar intraoperative fluorescence results could lead to different surgical treatment
strategies, which demonstrated the difficulties in interpretation of uncorrected fluorescence
signals. Real-time quantification and standardization of NIR fluorescence perfusion imaging
could probably aid surgeons in the nearby future.
