Non-thrombogenic hemofiltration system for acute renal failure treatment

Continuous arteriovenous hemofiltration (CAVH) has become an accepted therapy for patients with acute renal failure. A major technical concern with CAVH is clotting of the hemofilter, resulting from blood-material interactions. This study compares the thromboresistance and performance characteristics of a Duraflo II heparin treated CAVH circuit with those of an untreated control circuit. The circuit consisted of a polysulfone hemofilter, tubing sets, and catheters. The heparin treatment did not change the mass transfer properties of the hemofilter. The thromboresistance of the heparin treated circuit was compared directly with that of an untreated circuit in a heparinless sheep model using bilateral circuits. The heparin treatment significantly enhanced the blood compatibility of the circuit, as indicated by the reduction in thrombus formation, prolonged work life, and superior performance in heparinless sheep. There was minimal heparin leaching from the hemo-filter. A heparin treated circuit may improve the safety and effectiveness of the CAVH procedure, and offers potential for a systemic heparin protocol to be modified for patients with bleeding disorders.