Prolonged catheter survival in patients with acute kidney injury on continuous renal replacement therapy using a less thrombogenic micropatterned polymer modification

Abstract

Background: Continuous renal replacement therapy (CRRT) has been increasingly used in critically ill patients with acute kidney injury (AKI). One of the major properties that likely influence the catheter lifespan includes its surface specificity. We hypothesized that the improvement of blood-surface interaction by a reactive polymer film coating might reduce thrombogenic events in the vascular access device and subsequently lead to prolonged catheter survival in this clinical setting.

Methods: We compared, in a randomized study, the clinical application of two temporary catheters (TCs): one surface-modified double-lumen catheter (smDLC) and one standard sDLC with identical geometry and flow design. Efficacy end points were defined as the ability to complete at least 72 h CRRT without interruption due to TC dysfunction and ability to achieve blood flow rates of ≥150 mL/min. Safety end points were defined as the occurrence of catheter-related (CR) bacteraemia or other CR complications.

Results: We evaluated 236 critically ill patients (264 TCs) with AKI on CRRT (continuous venovenous haemodiafiltration) with age (mean±SD) of 56.9±17.9 years. The clinical investigation revealed that the number of hours before TC removal according to clinical requirements was significantly higher with smDLC as compared with sDLC (131±38 vs 113±21 h; P=0.004). Temporary catheter dysfunction occurred in 5% for smDLC and 14% for sDLC; P=0.001. Thrombosis of smDLC and sDLC was observed in 2.3 episodes per 1000 TC-days [95% confidence interval (CI), 1.9-2.5] and 4.2 episodes per 1000 TC-days (95% CI, 4.0-4.4), respectively; P=0.021. The blood flow rate was 221±29 mL/min vs 187±36 mL/min for smDLC and sDLC, respectively; P=0.012. Compared with the overall mean of TC dysfunction or thrombosis, the relative risk of premature removal (<72 h) was 0.43 (95% CI, 0.13-0.98; P=0.041) for smDLC and 2.51 (95% CI, 1.04-9.22; P=0.034) for sDLC with a significantly higher catheter-related bacteraemia rate in this latter group (P=0.008).

Conclusion: Micropatterned surface coating with a polyurethane polymer significantly increased TC survival with lower dysfunction rate, lower thrombotic events and better bacteriological barrier than sDLC in critically ill patients with AKI necessitating CRRT.