Original Article

Complement Activation Induced by Different Tubings Used for Cardiopulmonary Bypass

¹ Institute for Experimental Medical Research, University of Oslo,
² Department of Surgery, Ullevaal Hospital
³ Institute of Immunology and Rheumatology, The National Hospital, Oslo, Norway.

^* Address correspondence to: Vibeke Videm, MD. Institute for Experimental Medical Research, University of Oslo. Ullevaal Hospital. N-0407 Oslo 4. Norway.

Abstract

Complement activation induced by latex, polyvinylchloride, and silicone tubings for extracorporeal circulation was studied in 2 in vitro situations: Fresh whole human blood mixed with priming solution was circulated through 00 cm tubing lengths for 1 hour, and small tubing pieces were incubated in fresh human serum for 7 hours. Activation of C3 and of the terminal pathway (C5–C9) was assessed in enzyme immuno assays. In both situations complement activation was significantly higher (p<0.05) than in controls. During incubation, C3 activation started later with silicone, but increased to similar levels as with polyvinylchloride after 7 hours. Latex was a significantly more potent C3 activator at 7 hours than the other materials (p<0.05), whereas polyvinylchloride induced most terminal pathway activation (p<0.01). When blood was pumped through intact tubing, complement activation was similar with all materials. The differences found during incubation were apparently overshadowed by other factors in the dynamic situation. The study thus gives no evidence for preferring any of the tested tubing materials to reduce complement activation during in vivo extracorporeal circulation, even if the tubing does contribute to overall activation.