Laparoscopic assessment of intestinal wall microcirculation impairment using laser speckle contrast imaging

Abstract

Laparoscopic surgical interventions are widely used nowadays, and laser speckle contrast imaging (LSCI) is a promising optical method that provides additional diagnostic information. The aim of the study was to assess the dynamics of blood flow changes in the intestinal wall through the laparoscope using LSCI when modeling ischemia with following reperfusion.
The experiment was conducted on laboratory animals (Wistar rats, 4 months old, n = 3). Impairment of blood circulation in the intestinal wall was created by performing a laparotomy and applying a ligature to arcade vessels. In the course of the experiment two types of vessel occlusion were performed: mild occlusion and strong occlusion. To perform LSCI measurements, a laser with a wavelength of 785 nm was chosen. Monochrome images were acquired through a high-speed camera (30 frames per second and 33 ms exposure time). A specially developed optical fiber was used in order to couple the laser with a standard lighting port of the laparoscope.
Obtained raw monochrome images were analyzed using special processing algorithms to estimate the blood flow intensity. The results showed that mild vessel occlusion had little to no effect on blood flow, which was confirmed by the processed speckle images. At strong vessel occlusion there was a decrease in microcirculation, which was expressed in the decrease of speckle contrast intensity in the study area. After ligature removal, restoration of blood circulation was registered. Quantitative and qualitative data analysis revealed distinctions between differing functional states of biological tissue.

Speaker

Vadim N. Prizemin
Orel State University
Russia

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