Optical Coherence Tomography Angiography of the Intestine: How to Prevent Motion Artifacts in Open and Laparoscopic Surgery?

Abstract

(1) Introduction. The problem that limits the intraoperative use of OCTA for the intestinal circulation diagnostics is the low informative value of OCTA images containing too many motion artifacts. The aim of this study is to evaluate the efficiency and safety of the developed unit for the prevention of the appearance of motion artifacts in the OCTA images of the intestine in both open and laparoscopic surgery in the experiment; (2) Methods. A high-speed spectral-domain multimodal optical coherence tomograph (IAP RAS, Russia) operating at a wavelength of 1310 nm with a spectral width of 100 μm and a power of 2 mW was used. The developed unit was tested in two groups of experimental animals—on minipigs (group I, n = 10, open abdomen) and on rabbits (group II, n = 10, laparoscopy). Acute mesenteric ischemia was modeled and then 1 h later the small intestine underwent OCTA evaluation. A total of 400 OCTA images of the intact and ischemic small intestine were obtained and analyzed. The quality of the obtained OCTA images was evaluated based on the score proposed in 2020 by the group of Magnin M. (3) Results. Without stabilization, OCTA images of the intestine tissues were informative only in 32–44% of cases in open surgery and in 14–22% of cases in laparoscopic surgery. A vacuum bowel stabilizer with a pressure deficit of 22–25 mm Hg significantly reduced the number of motion artifacts. As a result, the proportion of informative OCTA images in open surgery increased up to 86.5% (Χ2 = 200.2, p = 0.001), and in laparoscopy up to 60% (Χ2 = 148.3, p = 0.001). (4) Conclusions. The used vacuum tissue stabilizer enabled a significant increase in the proportion of informative OCTA images by significantly reducing the motion artifacts.

Diagnosis of Skin Burn-Induced Colon Circulatory Disorders Using Optical Coherence Tomography Angiography and Laser Doppler Flowmetry (Experimental Study)

“…One of the technical problems hampering the study of the nature of pathological changes in the colon wall in burned people is absence of diagnostic technologies for a long-term monitoring of blood circulation and intestine wall structure. Adaptation of optical coherence tomography angiography (OCTA) to the application in the abdominal cavity on the contracting gut in vivo [9] allows for making a significant progress in solving this problem. Previously, OCTA has already been used for visualization of microvascular bed of various parts of the digestive tract: esophagus [10,11], stomach [12,13], small intestine [14,15], for investigation of experimentally modeled pathology, and in practical diagnostic activity, however, this method has not been employed to diagnose the colon condition on the experimental models of skin burn injury.…”

“…Previously it has not been possible due to a large number of motion artifacts and difficulty of OCTA probe fixation. However, the device for vacuum fixation of the OCTA probe to the tissue surface, designed by us, provided the acquisition of a series of high-quality OCTA images from one examined point in dynamics [9]. Thus, presently, it became feasible technically and methodologically to solve clinically and fundamentally significant task of exploring the reaction of microcirculatory colon bed for the presence of an extensive thermal burn in patients.…”