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Class I compression therapy improves lower limb vascular flow volume in patients with chronic venous insufficiency – a magnetic resonance imaging study

Chronic venous insufficiency (CVI) is a significant, yet often under-recognized cause of morbidity in the adult population worldwide and its treatment accounts for approximately 2 % of the health care budgets in the Western world [1, 2]. Although CVI may be asymptomatic, it is often associated with pain, discomfort and swelling and it can significantly impair quality of life [3]. Whilst the morbidity associated with the major complications of CVI, including thrombophlebitis and chronic leg ulceration, should not be under-estimated, complications including cellulitis and deep venous thrombosis can be life-threating. The diagnosis of CVI relies on a thorough clinical history and examination combined with non-invasive imaging, typically duplex sonography. However, magnetic resonance imaging (MRI) is useful to determine the severity and extent of CVI; [4, 5] removing duplex sonography associated operator-dependent variability, whilst providing additional anatomical information, including the visualization of stenoses, strictures, collateral vessels, vein wall thickening and oedema. In addition, MRI can reliably reproduce the hemodynamic changes seen in duplex sonography [5, 6] and is better placed than sonography to examine the deep pelvic veins, particularly in patients with obesity. Medical compression therapy is a linchpin in the treatment of CVI and class I compression stocking therapy is both well-tolerated and can significantly improve symptom severity [7, 8]. However, to date, there have been no studies directly examining the effect of medical compression therapy on hemodynamically relevant parameters in CVI using MRI. Therefore, we measured the ratio of blood flow in the common femoral artery (VFA) and vein (VFV), the venous arterial flow index (VAFI), before and during the application of class I compression stockings (18–20 mmHg) using phase contrast MRI in 40 patients (26 females and 14 males, mean age 55.5 years) with CVI at various stages (C0s C3, Ep, As, Pr) according to the CEAP classification [9]. The VAFI is a measure of the haemodynamic severity of venous insufficiency [5, 10]. All phase contrast MRIs were conducted in the out-patient setting (Radiology Practice, Groß Groenau, Germany) using 1.5 T whole-body MRI (Achieva, Philips GmbH, Hamburg, Germany) in the lying position. Exclusion criteria included the standard contraindications to MR imaging and the presence of peripheral arterial occlusive disease (ankle-brachial pressure index < 0.9). All patients provided written informed consent to participate in the study, which was approved by the Ethics Committee of the University of Lübeck (AZ 13–272) and performed according to the Declaration of Helsinki principles. SPSS 25 was used for statistical analysis. Mean values ± standard deviations of the VFV, VFA, and the ratio of the VFV/VFA were calculated. Differences were compared using a paired t-test. An analysis of variance (ANOVA) was used to evaluate the stage, sex and age-related VFV/VFA ratio differences. P-values less than 0.05 were regarded significant. Although, there was no significant change in venous flow under compression (p = 0.15), the arterial flow in the common femoral artery was significantly increased (5.62 ± 1.74 ml/sec before and 6.37 ± 2.00 ml/sec during compression, p = 0.0249). Overall, the ratio of VFV/VFA was not significantly altered (Figure 1). Whilst there was no evidence of a change in the ratio of VFV/VFA in the total study population, class I compression did significantly reduce this ratio when it was compared between patients with stage C2 and C3 and those with stage C0 and C1 disease. The mean difference in stage C0 was –0.05 ± 0.14 and C1 was –0.05 ± 0.22 compared with 0.07 ± 0.15 and 0.24 ± 0.23 in stages C2 and C3 respectively (p = 0.0179) (Figure 2). The limitations of our study include the relatively small sample size and its monocentric nature. Moreover, the extent to which changes in hemodynamic flow parameters can be extrapolated to the standing position is currently unknown. Nevertheless, there is evidence that MR assessment of CVI in the supine position is possible [5, 10] and that CVI is not a vascular pathology restricted to the standing position. Clinically, our study provides support for the use of class I compression stockings as part of the multi-modal treatment of CVI, even when patients are lying flat, and in patients with severe disease. In addition, it highlights the objective hemodynamic effects of compression on arterial vasculature; a novel finding which will be addressed in future studies. Whilst patients with CVI may not tolerate the nightly use of compression stockings, their use should be considered in elderly, immobile and bed-ridden patients. Future prospective studies should specifically examine the extent to which improvements in MR-measured blood flow during compression translate into a reduction in CVI symptoms and whether this is associated with a tangible clinical benefit in terms of halting disease progression and preventing complications including venous ulceration, thrombophlebitis, thrombosis and cellulitis [11]. Clinical Letter