Gravitational venous drainage is significantly faster in patients with varicose veins

Abstract

Objectives It has been proposed that varicose veins may be caused by a degree of impeded proximal venous drainage (pelvic venous obstruction) in the same way that biological tubes dilate in response to an obstruction. The venous drainage index (VDI) of air-plethysmography (APG) was used to test this hypothesis. A dependency to elevation manoeuvre was used to provoke gravitational venous drainage. A rapid reduction in calf volume implied good drainage. Methods This was a single centre, proof-of-concept study comparing gravitational venous drainage in varicose vein patients and controls. Leg filling and drainage manoeuvres (elevation to dependency and dependency to elevation) were performed three times per leg in 15 patients (7 male, 8 right) and 16 controls (3 male, 8 right). The VDI was measured in the same way the established venous filling index (VFI) is calculated to quantify filling: VDI = 90% of venous drainage volume (90VDV)/90% venous drainage time (VDT90). Results The patients were significantly older at 58 (41–75) years versus the controls 47 (18–58), p = 0.001. There was no significant difference between the groups in weight, height, BMI or common femoral vein diameter. The patients were ( C2 = 8; C3 = 1, C4 = 6), VCSS 4 (1–11) with a median refluxing proximal thigh saphenous diameter of 6 (5–11) mm. The median (inter-quartile range) VFI and VDI (both in mL/s) in the control tests ( n = 48) were 1.3 (0.9–1.9) and 33.8 (21.5–55), respectively. The VFI and VDI in the patient tests ( n = 41) were significantly faster at 6.2 (3.5–9.4), p < 0.0005, and 47.1 (36.1–66.3), p = 0.002, respectively. Adjusted to a standard mean for each leg, the reproducibility limits (×3) of the VDI was very good at 39.7 (95% CI: 36.5–42.9) in controls and 52.9 (95% CI: 49.7–56.1) in patients. Conclusion The VDI was significantly greater in patients with varicose veins compared to controls. It is unlikely that impeded gravitational drainage is a significant factor in the pathophysiology of varicose veins.