MODERN THEORIES OF PATHOGENESIS OF TROPHIC ULCER OF VENOUS ETIOLOGY

An important problem of vascular surgery is trophic ulcers of venous etiology. Despite the existence of this problem for several decades, no unified concept of the pathogenesis of trophic ulcers can be found in literature. Rapid development of phlebology in recent years formed new concepts of mechanisms of venous outflow from the lower limbs and of the pathogenesis of trophic ulcers. These concepts are not only of independent significance for physiology and pathophysiology, but they also influence development of new approaches to surgical treatment and creation of new pharmaceutical drugs for treatment for chronic venous insufficiency. The review of literature presents modern theories of formation of trophic ulcers: orthostatic and dynamic phlebohypertension, theory of fibrin ‘cuffs', of leukocyte aggression, of tissue hypoxia as a result of arteriolovenular anastomosis, lobular theory of the origin of trophic ulcers. In classic understanding, one of the leading pathogenetic mechanisms of derangement of circulation of cover tissues in patients with chronic diseases of the lower limb veins is considered to be dynamic phlebohypertension due to pathological retrograde blood flow via perforant veins of shin. However, the data of modern literature show reduction of significance of horizontal reflux for trophic disorders, the main mechanism is thought to be phlebostasis with subsequent or parallel leukocyte aggression. But these data not always receive confirmation. Other scientists propose a theory of formation of chronic venous failure, with the principal moment being enhancement of resistance to the venous outflow from the lower limbs followed by derangement of microcirculation. At the same time the question about the structural organization of perforant vessels remains open as well as the related question about participation of the arterial component in the pathogenesis of trophic ulcers. Confirmation of the role of arterial component in the pathogenesis of trophic ulcers will permit selection of therapy directed at more rapid healing of trophic ulcers and at prophylaxis of their recurrence.