MORPHOLOGICAL FEATURES OF THE POSTOPERATIVE WOUND IN ANORECTAL FISTULAS DEPENDING ON THE TREATMENT METHOD

Anorectal fistulas are prevalent conditions with rising incidence and substantial recurrence risk, making objective morphological comparison of treatment methods clinically important.The aim of the study was to identify and compare microscopic changes after surgical treatment of anorectal fistulas using the conventional method, laser ablation, and tissue welding.From 2020 to 2022, 34 patients (29 men, 5 women; 24-65 years) underwent surgery in a university surgical clinic and were allocated to group 1 (conventional surgery), group 2 (laser ablation), or group 3 (tissue welding), with postoperative wound sampling for histology.Tissue was fixed in 10% neutral buffered formalin, processed routinely, embedded in paraffin, sectioned at 4-5 μm, and stained with hematoxylin and eosin, followed by mounting for evaluation.Microscopy was performed with an OLIMPUS BX 41 light microscope at ×40-×1000 magnifications, and the study was approved by the institutional Bioethics Committee in accordance with international and national regulations.In group 1, the vascular component showed pronounced microcirculatory disorders (congestion with stasis, diapedesis hemorrhages, perivascular edema, endothelial proliferation), often with venous outflow impairment and signs consistent with local tissue hypoxia.Group 1 also demonstrated marked perivascular round-cell infiltration, occasionally mixed with plasmacytic elements, with thrombi in small vessels, foci of angiogenesis with fragile thin-walled neocapillaries, and frequent perivascular fibrosis with collagen accumulation around vessels and areas with fewer functionally active capillaries.The stromal component in group 1 was characterized by numerous inflammatory infiltrates (predominantly neutrophils and macrophages), immature connective tissue with young fibroblasts, chaotic and fragmented collagen, prominent edema, uneven vascularization, and remnants of necrotic tissue/detritus.In group 2, vessels more often had moderate blood filling with rare stasis, a lower intensity and prevalence of perivascular inflammation, and a better-formed network of newly formed small vessels, although endothelial injury with lumen narrowing, desquamation, plasmatic imbibition, Журнал «Перспективи та інновації науки» № 1(59) 2026 2039 occasional thrombi, and small necrotic masses could still be present.In group 3, vessels generally had preserved endothelium with no necrotic vascular changes, minimal perivascular infiltration, scarce fibrotic and necrotic elements, and the stroma showed the most mature organization with dense, well-arranged collagen, minimal edema, and a well-developed capillary system.Overall, the findings indicate that conventional surgery is associated with less mature stromal repair and more prominent inflammatory and microcirculatory disturbances, whereas laser ablation shows reduced inflammation with more organized repair features, and tissue welding demonstrates the most favorable microscopic pattern with near absence of necrosis and inflammation.