Method of Objective Assessment of Intestinal Viability Using “Smart Light” Polychrome LED Light Source for Contrast Imaging of Biological Tissues during Surgical Operations

Introduction. Diseases accompanied by a violation of the blood supply to the intestinal wall occupy one of the main places in urgent surgery of the abdominal organs. Intraoperative assessment of intestinal viability is one of the most difficult tasks and plays a leading role in determining the volume of surgical aid, predicting the course of the postoperative period.
Aim. To study the possibility of using contrast imaging using a controlled polychrome LED light source to assess the viability of the intestinal wall of a model animal in conditions of acute ischemia.
Materials and methods. The work is based on the results of experimental studies conducted on 15 clinically healthy sexually mature laboratory rats. The simulation of acute small intestine ischemia lasting from 15 minutes to 12 hours was performed by ligation of the major vessels. Each animal underwent a relaparotomy after a corresponding time interval. The intestine was extracted from the abdominal cavity and visual parameters of wall necrosis were assessed using the Kerte method and using a polychrome LED light source for contrast imaging of biological tissues during surgery. After determining the visual signs of necrosis, intestinal fragments were submitted for pathomorphologic examination. The study was ended by removing the animal from the experiment according to the protocol approved by the Ethics Committee.
Results. The spectral composition of the light source providing the most reliable detection of necrosis of the intestinal wall is represented by two spectral bands with maximum wavelengths of λpeak = 503 nm, λpeak = 594 nm and an approximate ratio of band intensities of 2:1. By morphological study, the following intervals were found to be significant when simulating small intestinal ischemia in the experiment: 1 hour after ligation - time of onset of ischemia, 6 hours - time when ischemia is reversible, and 12 hours - time when small intestine necrosis is recorded.
Conclusions. The use of a controlled shadowless semiconductor light source for contrast imaging of biological tissues during surgery in the selected mode improves the definition of visual parameters of intestinal viability.