Real-time Quantification of Small Intestine Perfusion and Responses to Arterial Versus Venous Occlusion Using Laser Speckle Contrast Imaging in Porcine Intestinal Model

Abstract

Abstract Purpose: Real time intraoperative perfusion assessment may reduce anastomotic leaks. Laser Speckle Contrast Imaging (LSCI) provides dye-free visualization of perfusion by capturing coherent laser light scatter from red blood cells, and displays perfusion as a colormap. Herein, we report a novel method to precisely quantify intestinal perfusion using LSCI.Methods: ActivSightTM is a FDA-cleared multi-modal visualization system that can detect and display perfusion via both Indocyanine Green imaging (ICG) and LSCI in minimally invasive surgery. An experimental prototype LSCI perfusion quantification algorithm was evaluated in porcine models . Porcine small bowel was selectively devascularized to create regions of perfused/watershed/ischemic bowel and progressive aortic inflow/portal vein outflow clamping was performed to study arterial vs. venous ischemia. Continuous arterial pressure was monitored via femoral line.Results: LSCI perfusion colormaps and quantification distinguished between perfused, watershed, and ischemic bowel in all vascular control settings: no vascular occlusion (p = 1.52 x 10-15), aortic occlusion (p = 9.58 x 10-13), and portal venous occlusion (p = .00193). LSCI quantified similar levels of ischemia induced by states of arterial inflow and venous outflow occlusion. LSCI-quantified perfusion values correlated positively with higher mean arterial pressure and with increasing distance from ischemic bowel.Conclusion: LSCI relative perfusion quantification may provide more objective real-time assessment of intestinal perfusion, by quantifying currently subjective gradients of bowel ischemia and recognizing both arterial/venous etiologies of ischemia.