The Biomechanics of Venous Remodeling

Abstract

The remodeling of veins is associated with an alteration of both the architecture as well as the functional properties of the vein wall. On the morphological level, such changes contribute to the development of bulged and dilated varicose or spider veins. On the functional level, they may evoke venous insufficiency, which is characterized by reflux of venous blood or disturbed flow and elevated intraluminal pressure levels. While the primary cause of venous remodeling remains obscure in the majority of cases, epidemiological and etiological studies indicate that the development of varicose veins is driven by risk factors, which support the development of venous hypertension and thus chronically augment circumferential stress of the venous wall (e.g., dysfunctional venous valves, pregnancy, or obesity). As such, changes in flow and blood pressure appear to act as both cause and consequence of venous remodeling, thereby delineating pathophysiological biomechanical parameters as critical determinants of impaired vein function. This review intends to highlight biomechanical forces capable to activate vascular endothelial and smooth muscle cells in the vein wall and discuss the underlying molecular mechanisms. A special emphasis is given to pressure-induced circumferential wall stress as a plethora of experimental and epidemiological evidence underlines the relevance of venous hypertension for venous remodeling processes.