The effect of short-term low molecular weight heparin on patency following successful salvage of arteriovenous access with recurrent thrombosis.

OBJECTIVE This study aims to investigate the effect of low molecular weight heparin (LMWH) in maintaining the patency of AV access with recurrent thrombosis. METHODS Following successful thrombectomy, 66 patients with recurrent thrombosis were included in the study. The primary, assisted primary and secondary patency rates of patients who received LMWH (n = 24) were compared with those who did not receive anticoagulant (n = 42) using Kaplan-Meier analysis. Cox-regression analysis was performed to investigate potential predictors of patency rates. RESULTS The mean dose of enoxaparin used was 40 ± 13.1mg or 0.74 ± 0.2 mg/kg daily for a median duration of 14 (IQR 7,28) days. The mean trough anti-Xa concentrations measured after 2 doses of LMWH was 0.17 ± 0.13 IU/mL. Kaplan-meier analyses for mean primary, assisted primary and secondary patency rates of LMWH vs. no anticoagulation groups were 149 (95% CI: 91 - 207) vs. 87 (95% CI: 42 - 132) days (p < .006), 230 (95% CI: 142 - 320) vs. 107 (95% CI: 62 - 150) days (p = .01) and 438 (299 - 579) vs. 294 (95% CI: 197 - 392) days (p = .08) respectively. LMWH remained a significant protective predictor of primary (HR: 0.49; 95% CI: 0.25 - 0.86; p = .02) and assisted primary patency rates (HR: 0.51; 95% CI: 0.27 - 0.98; p = .04) after adjusting for patient age, access age, type of AV access, presence of peripheral vascular disease and haemoglobin levels. CONCLUSIONS LMWH may improve short and mid-term patency rates for AV accesses with recurrent thrombosis. This article is protected by copyright. All rights reserved.