Accelerated Hemocompatibility Testing of Rotary Blood Pumps

Ex vivo hemocompatibility testing is a vital element of pre-clinical assessment for blood-contacting medical devices. Current approaches are resource intensive; thus, we investigated the feasibility of accelerating hemocompatibility testing by standardizing the number of pump exposures in loops of various sizes. Three identical blood loops were constructed, each with a custom-molded reservoir able to facilitate large -volume expansion. Using the HVAD rotary blood pump operating at 5 L.min(-1) and 100 mmHg, three test volumes (80, 160, and 320 ml) were circulated for 4000 pump exposures. Blood sampling was performed at individualized intervals every one-sixth of total duration for the assessment of hemolysis and von Willebrand Factor (vWF) degradation. While steady increases in hemolysis (similar to 24 mg.dl(-1)) were identified in all tests at completion, loop volume was not a primary discrimi-nator. The normalized index of hemolysis did not vary signifi-cantly between loops (4.2-4.9 mg.100 L-1). vWF degradation progressively occurred with duration of testing to a similar extent under all conditions. These data support an acceler-ated approach to preclinical assessment of ex vivo blood damage. Adopting this approach enables: enhanced efficiency for rapid prototyping; reduced ex vivo blood aging, and; greater utility of blood, which is presently limited if 450 ml loops are desired.