Peculiarities of paravulvar microcirculation in skin and muscle in blast wound in variants of early local injection of reparative active agent

Abstract

Introduction. A promising method of correcting microcirculatory disorders in the area of soft tissue injury is the use of agents with antihypoxant action, which include deproteinized calf-blood hemoderivate.The aim of the work was to reveal the peculiarities of subcutaneous and intramuscular local injection of deproteinized calfblood hemoderivate on the changes of microcirculation in the skin and muscles in the experimental blast wound area.Materials and methods. The experiments were performed on 90 male Wistar rats weighing (320±20) g in compliance with international rules of work with laboratory animals. Modeling of an explosive wound of the soft tissues of the femur with mild degree of blood loss was carried out according to the original author’s method (Patent RU No. 2741238 dated 22.01.2021). After primary surgical treatment was performed paravulnarly, deproteinized calf-blood hemoderivate was injected intramuscularly, intramuscularly and subcutaneously (Actovegin drug) once in six points with an insulin syringe. Microcirculation in the skin and muscles of the injured area was assessed by laser Doppler flowmetry using the device LAKK-M (Russia). To determine the normal values of microcirculation, data obtained from healthy animals were used.Results. Local intramuscular injection into the paravular area resulted in an increase of the constant perfusion component (M) by 24.1−35.9 % (p < 0.05) and by 18.0−56.4 % (p < 0.05) in the skin and muscles during all periods of observation, an increase of the variable perfusion component (σ) in the skin by 31.4−38.0 % (p < 0.05) during 28 days and in muscles by 8.8−58.7 % (p < 0.05) during the first 14 days only, increase of Kv ratio in skin by 12.4 % (p = 0.01) early after injury (7 days) and decrease in muscles by 18.3−20.8% (p < 0.05) at 14−28 days. Local combined administration (intramuscularly and subcutaneously) of the drug around the wound promoted the increase of the constant perfusion component (M) in the skin by 23.8 % (p = 0.005) and 6.9 % (p = 0.01) at the 7th and 28th days of observation, increase of σ index in skin by 14.2−45.1 % (p < 0.007) on the 7−14 days and its decrease in muscles by 15.7 % (p = 0.009) by the end of the 7th day of observation in comparison with animals after only intramuscular injection only. Also, the coefficient of variation (Kv) with the combined route of injection was increased in the skin by 8.8−23.8 % (p < 0.009) in the first 14 days and decreased in the muscles by 15.7 % (p = 0.008) in the early period after injury (7 days) relative to its values in animals with intramuscular injection.Discussion. The results of the study allow noting the stimulating effect of deproteinized calf-blood hemoderivate on neovasculogenesis in the damaged tissues, which can be judged by the increase in the constant perfusion component (M). In addition, we can conclude that the direct endothelium-protective effect of the drug consists in the modulation of microcirculatory flow, which confirms the significant increase in the variable perfusion component (σ) throughout the experiment.Conclusion. Local paravular administration of deproteinized calf-blood hemoderivate in experimental blast wound promotes microcirculation increase in the soft tissues of the injury area. Combined (intramuscular and subcutaneous) local paravular injection of the drug allows more effective stimulation of microcirculation in the skin and muscles of the injury area.