[How to predict thrombosis of arteriovenous fistule?]

Atherosclerosis is accelerated in hemodialysis patients. Cardiovascular calcifications, inflammation, dislipidemia and infection are common. Vascular access remains the Achilles' heel of successful hemodialysis, and thrombosis is the leading cause of vascular access failure. With periodic measurement of recirculation, it is possible to prevent thrombosis and to avoid unnecessary expenses and time-consuming procedures. It remains uncertain whether recirculation measurements correlate with biochemical markers such as disturbances in mineral metabolism, anemia, dislipidemia and infection.

Forty-one hemodialysis patients with native arteriovenous fistula (AVF) and adequate hemodialysis (eKt/V > or = 1.2) were included in the study. Two groups of patients were defined: group A including 17 patients with AVF at risk (recirculation > or = 10%) and group B including 24 control patients with well functioning AVF (recirculation < 10%). In all patients we measured recirculation using Blood Temperature Monitor (BTM, Fresenius Medical Care). All group A patients underwent Doppler examination and/or fistulography. Serum concentrations of total cholesterol, HDL and LDL cholesterol, triglycerides, C-reactive protein, hemoglobin, hematocrit, calcium, phosphorus, calcium phosphorus product and intact parathormon were determined in group A six months before the incident (fistula stenosis or thrombosis) and in group B six months before the study.

Group A patients had significantly higher recirculation than group B patients. Elevated recirculation (> or = 10%) poses a significant risk for the development of AVF stenosis and thrombosis. There was a significant difference between group A and B according to calcium phosphorus product and LDL cholesterol. During the study, there were 0.025 thromboses per patient year in group A and no thromboses in group B.

During the study, thrombosis of native AVF was more common in patients with mineral and lipid metabolism disturbances. Using recirculation measurements we could identify patients at a high risk for the development of thrombosis. It enables early diagnosis and early intervention to prevent complications and prolong the patency of AVF.

Our study showed elevated recirculation (recirculation < or = l0%) to pose a significant risk for the development of stenosis progressing to thrombosis. BTM measurements are sufficiently reproducible and offer an opportunity to extend access monitoring to all hemodialysis patients. Further studies are required to correlate biochemical markers with AVF stenosis and thrombosis in dialysis patients.