Micro-arteriovenous fistula in patients with lower limb lymphedema

Abstract

Background A micro-arteriovenous fistula (AVF) is a minute, short shunt between an artery and a vein that does not pass through a capillary. We investigated the association between micro-AVFs and lymphedema using computed tomography angiography (CTA) and venous blood gas analysis.<br/>Methods In 95 patients with lower limb lymphedema, the presence or absence of early venous return (EVR) was compared between patients with primary and secondary lymphedema. Furthermore, we investigated the difference in the timing of edema onset in patients with secondary lymphedema with or without EVR using CTA. In 20 patients with lower limb lymphedema with confirmed early EVR in a unilateral lower limb, the partial pressure of oxygen (PO2) was compared between the lower limb with EVR and the contralateral lower limb.<br/>Results Secondary lymphedema with or without EVR occurred at an average of 36.0±59.3 months and 93.5±136.1 months, respectively; however, no significant difference was noted. PO2 was 57.6±11.7 mmHg and 44.1±16.4 mmHg in the EVR and non-EVR limbs, respectively, which was a significant difference (P=0.005).<br/>Conclusions EVR and venous blood gas analysis suggested the presence of micro-AVFs in patients with lower extremity edema. Further research is warranted to examine the cause of micro-AVFs, to advance technology to facilitate the confirmation of micro-AVFs by angiography, and to improve lymphedema by ligation of micro-AVFs.

Cyanoacrylate closure for arteriovenous fistula in the lower extremity with saphenous vein insufficiency

“…1 In some reports, collateral circulation and venous congestion have also been suspected factors, although sometimes unknown, such as in the present cases. 2 , 3 , 4 The diagnosis is simple using contrast-enhanced CT. We use iohexol 300 for lower extremity arteriography, with 150 mL injected intravenously and imaging performed 30 seconds later. If no arteriovenous shunting is present, most veins are usually not imaged at this time.…”