Real-time quantification of intestinal perfusion and arterial versus venous occlusion using laser speckle contrast imaging in porcine model

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: ActivSight TM 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 quanti cation algorithm was evaluated in porcine models .Porcine small bowel was selectively devascularized to create regions of perfused/watershed/ischemic bowel and progressive aortic in ow/portal vein out ow clamping was performed to study arterial vs. venous ischemia. Continuous arterial pressure was monitored via femoral line.Results: LSCI perfusion colormaps and quanti cation 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 quanti ed similar levels of ischemia induced by states of arterial in ow and venous out ow occlusion. LSCI-quanti ed perfusion values correlated positively with higher mean arterial pressure and with increasing distance from ischemic bowel.Conclusion: LSCI relative perfusion quanti cation 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.

Real-time quantification of bowel perfusion using Laparoscopic Laser Speckle Contrast Imaging (LSCI) in a porcine model

“…We have previously published in preclinical and clinical studies using ActivSight at this distance, as well as both larger and smaller distances intra- and extra-corporeally. Our preclinical studies in porcine models have been both laparoscopic and open, at varying distances, and have translated well to intracorporeal and extracorporeal human usage at standard distances in the OR [ 15 – 17 , 23 , 24 ]. RPUs were calculated using computational processing on the LSCI generated perfusion heatmap images.…”