Abstract
Objective: Reflux within the superficial microvenous network may play a critical role in the development of skin changes associated with chronic venous insufficiency. This study aimed to extend previous ex vivo observations to determine the in vivo utility of near infra-red fluorescence (NIRF) imaging to assess superficial venous reflux in the leg.
Methods: A total of 28 limbs were examined in seventeen participants. These included limbs with (CEAP C2 n=6, C3 n=1 & C4 n=15) and without (CEAP C0, n=6) venous disease. Indocyanine green (5mL @ 0.1mg/mL) was infused via an (antegrade) cannula in the distal great saphenous vein and the medial leg imaged using NIRF. Venous reflux was assessed using the Valsalva manoeuvre, with or without superficial outflow obstruction (thigh cuff inflated to 50mmHg).
Results: Consistent with our previous ex vivo study, NIRF imaging visualised a wide range of different microvenous reflux patterns in vivo. These included focal and diffuse regions of fluorescence within the skin, the extent of which appeared to be associated with venous disease (CEAP C classification) severity. The observed reflux patterns also appeared to be functional correlates of perforator vein or saphenofemoral junctional incompetence.
Conclusion: This preliminary in vivo study provides proof-of-principle observations suggesting a potential novel method for investigating microvenous reflux in superficial venous disease.