Research results microcirculation of the intestinal wall in adhesive acute intestinal obstruction using non-contact laser Doppler flowmetry in an acute experiment

Objective: to evaluate the dynamics of intestinal wall perfusion in adhesive acute intestinal obstruction and to determine the critical period of reversibility of ischemic changes. Material and methods. The study was performed in 50 rats in an acute experimental setting. Chronic adhesive disease was induced 30 days prior to the main experiment. Animals were divided into a control group (laparotomy without adhesions) and four experimental groups with adhesive disease: sham group (without obstruction), group A (strangulation for 1 hour), group B (24 hours), and group C (48 hours). Microcirculation was measured using non-contact laser Doppler flowmetry with vibration noise suppression; the M1 parameter (first spectral moment reflecting blood flow intensity, TPU) was evaluated. Statistical analysis was performed using STATISTICA 10.0 with parametric and non-parametric tests. Results. Peritoneal adhesions were found to reduce basal perfusion by 10.5% (0.95±0.05 vs 0.85±0.06 TPU; p=0.0256). Initiation of strangulation resulted in a sharp decrease in M1 by approximately three-fold within the first 10 minutes (to 0.34±0.09 TPU). Perfusion recovery after obstruction resolution depended on ischemia duration: at 1 hour, 68% of baseline level was recovered; at 24 hours, 24%; at 48 hours, no recovery was observed (p=0.567), indicating development of the irreversible “no-reflow” phenomenon. Conclusion. After strangulation, perfusion levels progressively decreased until the development of “biological zero” of microcirculation. The critical period of ischemia reversibility in adhesive strangulation is in the range of 24–48 hours.