Hematologic evaluation of cardiopulmonary bypass circuits prepared with a novel block copolymer.
BACKGROUND
To decrease the complications associated with cardiopulmonary bypass, novel biomaterials have been introduced that may be less thrombogenic than standard synthetic surfaces.


METHODS
Thirty-four patients undergoing coronary artery bypass grafting were randomized to bypass using either a control circuit or a circuit prepared "tip-to-tip" with a triblock-copolymer (polycaprolactone-polydimethylsiloxane-polycaprolactone).


RESULTS
There was a progressive increase in thrombin generation in the control group during bypass, which was not seen in the test group. The test surface decreased the release of tissue plasminogen activator and plasmin-alpha2-antiplasmin complex formation (p<0.005). There was also an increased platelet count and a decreased platelet activation in the test group, as detected by GMP-140 expression and beta-thromboglobulin release (p = 0.017). There was also significantly more debris that accumulated on the arterial filter in the control group, as confirmed by scanning electron microscopy.


CONCLUSIONS
This clinical trial has demonstrated a significant difference in the hematologic effects of the test circuits, with evidence of platelet preservation, decreased fibrinolysis, and decreased thrombin generation. A larger trial would be necessary to establish the clinical relevance of these differences.
Rubens
F D
FD
Division of Cardiac Surgery, University of Ottawa Heart Institute, Ontario, Canada. frubens@heartinst.on.ca
Labow
R S
RS
Lavallée
G R
GR
Watson
M I
MI
Robblee
J A
JA
Voorhees
M E
ME
Nathan
H J
HJ
D000990:Antithrombin III / Q000378:metabolism; D001672:Biocompatible Materials; D001777:Blood Coagulation; D002315:Cardiopulmonary Bypass / Q000295:instrumentation*; D001026:Coronary Artery Bypass; D004129:Dimethylpolysiloxanes; D005260:Female; D005342:Fibrinolysis; D005374:Filtration; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood; D010447:Peptide Hydrolases / Q000378:metabolism; D015539:Platelet Activation; D010976:Platelet Count; D011091:Polyesters; D011108:Polymers; D012828:Silicones; D013917:Thrombin / Q000096:biosynthesis; D010959:Tissue Plasminogen Activator / Q000097:blood; D001620:beta-Thromboglobulin / Q000032:analysis
D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D019007:P-Selectin; D011091:Polyesters; D011108:Polymers; D012828:Silicones; C046193:antithrombin III-protease complex; D001620:beta-Thromboglobulin; C016240:polycaprolactone; C013830:baysilon; D000990:Antithrombin III; D010447:Peptide Hydrolases; D013917:Thrombin; D010959:Tissue Plasminogen Activator