Chronic Venous Insufficiency - A One-dimensional Blood Flow Modelling Assessment of Venous Valves, Perforators,...

Compression therapy is the primary treatment for chronic venous insufficiency, yet hemodynamic mechanisms through which it improves venous function remain incompletely understood. This study investigates the effects of venous valves and external compression on flow and pressure distribution in the lower-limbs using a novel one-dimensional computational model of venous hemodynamics.

The model includes major deep and superficial veins interconnected by perforators, collapsible vessel mechanics, dynamic valve behavior, gravitational effects, and calf muscle activity to represent the hemodynamics of a generic lower-limb. The collapsible vessel formulation was validated against published numerical and experimental studies, while simulated lower limb hemodynamics were compared with published in vivo measurements.

Valve competence restores physiological pressure and velocity profiles and reduces common femoral vein reflux (0.501 mL for 5s muscle contraction cycle), whereas incompetence leads to elevated pressures, bidirectional perforator flow, and higher reflux volumes (5.922 mL for 5s muscle contraction cycle). Perforators enhance deep venous return under healthy conditions. External compression reduces reflux during muscle relaxation by increasing superficial venous resistance, resulting in a 19% increase in venous return at the common femoral outlet. Simulated pressures agree with in vivo data, with higher values during relaxation in the pathological configuration. Conclusion & Significance: The proposed framework provides a comprehensive and validated computational tool for studying venous hemodynamics, explicitly accounting for venous valve dynamics and external compression. It offers mechanistic insight into their role in regulating flow and pressure distribution, supporting the optimization of compression-based therapies for chronic venous insufficiency.