[Chronic venous occlusion in hemodialysis-related fistula: diagnosis and endovascular treatment].

The main reasons of fistula dysfunction are stenosis and thrombosis. There are two kinds of thrombosis: acute and chronic. Acute thrombosis is total fistula occlusion while chronic occlusion is partial venous occlusion with collateral veins, which lead to impair fistula's function. 450 dialysis fistulas were referred to US (ultrasound) examination. Among 392 patients with fistula dysfunction, 71 presented chronic venous occlusion in hemodialysis shunt. 35 patients were qualified to endovascular recanalization. The mean length of the occluded segment was 3-35 cm (subclavian vein 2-4 cm). 38 patients underwent angiography (35 before endovascular treatment). Technique of recanalization included antegrade venous puncture, insertion guidewire (0.021'), catheter (5 Fr), balloon catheter (5-8 mm) and in 2 cases stent placement. Colour Doppler allowed to diagnose 34 (97%) cases of chronic venous occlusion in hemodialysis shunt. Decrease of mean flow volume in brachial artery--709 +/- 395 ml/min. (50-1500 ml/min) was statistically significant (p = 0.0015). Normal mean flow volume was 1242 +/- 641 ml/min. 20 of 35 recanalization procedures were performed successfully. The main reason of failure was perforation or false channel. Mean primary patency was 75% after 3 months. Mean cumulative was 85% (10/12) after 6 months. Chronic venous occlusion is often present in hemodialysis shunt and reduces flow volume. Percutaneous recanalization results aren't magnificent but there is only kind treatment for many patients with fistula failure.