Microcirculation of the gastrogastrointestinal wall in acute adhesive intestinal obstruction using non-contact laser doppler flowmetry in an acute experiment

Objective: to evaluate the dynamics of gastrointestinal wall perfusion in acute adhesive intestinal obstruction and to determine the critical period of reversibility of ischemic changes. Materials and Methods: The study was conducted on 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 (strangulation for 24 hours), and group C (strangulation for 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). The initiation of strangulation resulted in a sharp, approximately three-fold decrease in M1 within the first 10 minutes (to 0.34±0.09 TPU). Perfusion recovery after obstruction resolution depended on the duration of ischemia: after 1 hour, 68% of the baseline level was recovered; after 24 hours, 24%; and after 48 hours, no recovery was observed (p=0.567), indicating the development of the irreversible "no-reflow" phenomenon. Conclusion: Following 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.