MORPHOLOGICAL CHANGES AND TISSUE REPAIR IN THE INTESTINE AND MESENTERY FOLLOWING EXPERIMENTAL BLUNT ABDOMINAL TRAUMA

Objective. To investigate the dynamics of morphological changes in the intestinal wall and mes­entery following experimental blunt abdominal trauma and to evaluate tissue repair associated with low-level laser therapy and combined platelet-rich plasma (PRP) and laser treatment.

Materials and Methods. Serial histological sections of the small intestine and mesentery were examined at 24 hours and on days 3, 7, and 14 after experimental blunt abdominal trauma. Intact tissue served as a morphological reference. Post-traumatic changes were compared among control animals, animals receiving low-level laser therapy, and animals receiving combined PRP and laser treatment. Histological and morphometric assessments included villus height, mucosal thickness, inflammatory in­filtration, interstitial edema, hemorrhage, and fibrotic remodeling.

Results. In untreated animals, acute microcirculatory disturbances and epithelial damage were followed by pronounced inflammation on day 3 and progressive fibrotic remodeling. Low-level laser therapy was associated with earlier restoration of mucosal architecture and reduced inflammatory changes. On day 14, villus height reached 432±18 μm in controls, 471±15 μm after laser therapy, and 479±14 μm after combined treatment, compared with 482±16 μm in intact animals. Fibrotic remodeling scores were 2.7±0.1, 1.1±0.1, and 0.4±0.1, respectively. Combined treatment was associated with more complete structural recovery and less pronounced connective tissue remodeling.

Conclusion. Experimental blunt abdominal trauma produced sequential inflammatory, repara­tive, and fibrotic changes in the intestinal wall and mesentery. Laser therapy, particularly in combination with PRP, was associated with improved morphological recovery and reduced fibrosis. These findings provide an experimental basis for further investigation of approaches aimed at limiting post-traumatic tissue remodeling.