Real-time visualization of renal microperfusion using laser speckle contrast imaging.

Wido Heeman,Joost Calon,E Christiaan Boerma,Henri Leuvenink,Hanno Maassen,Gooitzen M Van Dam,Harry Van Goor

doi:10.1117/1.jbo.26.5.056004

Abstract

.Significance: Intraoperative parameters of renal cortical microperfusion (RCM) have been associated with postoperative ischemia/reperfusion injury. Laser speckle contrast imaging (LSCI) could provide valuable information in this regard with the advantage over the current standard of care of being a non-contact and full-field imaging technique.Aim: Our study aims to validate the use of LSCI for the visualization of RCM on ex vivo perfused human-sized porcine kidneys in various models of hemodynamic changes.Approach: A comparison was made between three renal perfusion measures: LSCI, the total arterial renal blood flow (RBF), and sidestream dark-field (SDF) imaging in different settings of ischemia/reperfusion.Results: LSCI showed a good correlation with RBF for the reperfusion experiment (; ) and short- and long-lasting local ischemia (; and ; , respectively). The correlation decreased for low flow situations due to RBF redistribution. The correlation between LSCI and SDF (; ) showed superiority over RBF (; ).Conclusions: LSCI is capable of imaging RCM with high spatial and temporal resolutions. It can instantaneously detect local perfusion deficits, which is not possible with the current standard of care. Further development of LSCI in transplant surgery could help with clinical decision making.

Highlights

Intraoperative-hampered renal cortical microperfusion (RCM) during, for example, anastomosis has been associated with ischemia/reperfusion-injury related postoperative complications
We report on the use of laser speckle contrast imaging (LSCI), a real-time, non-contact, full-field imaging technique with a large FOV that can visualize blood flow in tissues without the administration of a fluorescent dye,[12] to monitor RCM in human-sized porcine kidneys
All kidneys warmed-up to 37°C, which led to an increase in RCM (Fig. 3.)

Summary

Introduction

Intraoperative-hampered renal cortical microperfusion (RCM) during, for example, anastomosis has been associated with ischemia/reperfusion-injury related postoperative complications.Journal of Biomedical OpticsDownloaded From: https://www.spiedigitallibrary.org/journals/Journal-of-Biomedical-Optics on 10 Nov 2021 Terms of Use: https://www.spiedigitallibrary.org/terms-of-useMay 2021 Vol 26(5)Heeman et al.: Real-time visualization of renal microperfusion using laser speckle contrast imagingOthers have shown the potential of near-surface perfusion imaging for the prediction of postoperative complications, including reduced creatinine clearance, delayed graft function, and even graft rejection.[1,2,3,4] As such, it is conceivable that intraoperative monitoring of RCM using optical imaging methods may support surgical decision making, which may lead to improved perfusion during organ reperfusion and potentially contribute to a reduction in unfavorable postoperative outcomes.The value of the common techniques, such as postoperative duplex sonography or an arterial renal blood flow (RBF) probe, to monitor total RBF is limited by the fact that such techniques do not account for local perfusion heterogeneities.[5]. Others have shown the potential of near-surface perfusion imaging for the prediction of postoperative complications, including reduced creatinine clearance, delayed graft function, and even graft rejection.[1,2,3,4] As such, it is conceivable that intraoperative monitoring of RCM using optical imaging methods may support surgical decision making, which may lead to improved perfusion during organ reperfusion and potentially contribute to a reduction in unfavorable postoperative outcomes. Its general application is limited by substantial operator dependency.[5] Others reported on the use of contact imaging methods to directly visualize and quantify red blood cell (RBC) movement.[2,3] These methods yielded promising results regarding certain cut-off values for delayed graft function, postoperative creatinine levels, or even allograft rejection with RCM measurements performed as soon as 5 min after reperfusion.[1,2,3,4] The main limitation of these methods is the small (∼1 mm2) field-of-view (FOV) in which the RCM can be visualized. The administration of the fluorescent dye, which is required each time the perfusion is measured, hinders the surgical procedure

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