title: Improved biocompatibility of heparin surface-coated ventricular assist devices.
abstract: Heparin surface coated ventricular assist devices (VADs) and cannulas were evaluated in comparison to uncoated VADs in 10 bovine experiments (body weight 77 +/- 6 kg). All systems were primed with cristalloid solution. No systemic heparin was given. Left ventricular assist was started with a blood flow of 4.2 +/- 0.4 l/min and maintained over 6 hours. Besides hemodynamic monitoring, blood samples were taken at regular intervals for blood gas, hematological, biochemical and coagulation studies. All animals in the study group (coated) were assisted for the scheduled 6 hours without device failure. In the control group, however, total occlusion occurred in 1 VAD after 1 hour of left ventricular assist whereas the other 4 VADs remained functional throughout the protocol. Mixed venous oxygens saturation was preassist 56 +/- 12% for coated versus 63 +/- 11% for uncoated and the final value at 60 minutes after weaning was 58 +/- 16% versus 59 +/- 5% (NS). Mean hematocrit dropped from a baseline value of 33 +/- 4% for coated versus 29 +/- 8% for uncoated to 29 +/- 7% versus 30 +/- 5% (NS) after 6 hours of assist. There was no significant difference between the baseline values (5.7 +/- 3.0 mumol/l for coated versus 4.6 +/- 3.1 mumol/l for uncoated) and the 6-hour values (3.8 +/- 3.7 mumol/l versus 7.6 +/- 6.4 mumol/l) for mean plasma hemoglobine. The normalized platelet levels dropped after 10 minutes of assist to 91 +/- 21% for coated versus 94 +/- 49% for uncoated (NS) and 89 +/- 29% versus 65 +/- 44 at 6 hours (NS).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Clinic for Cardiovascular Surgery, University Hospital, Zürich, Switzerland.
authors.forename: L K
authors.initials: LK
authors.lastname: Von Segesser
authors.forename: B M
authors.initials: BM
authors.lastname: Weiss
authors.forename: E
authors.initials: E
authors.lastname: Hänseler
authors.forename: B
authors.initials: B
authors.lastname: Bisang
authors.forename: B
authors.initials: B
authors.lastname: Leskosek
authors.forename: A
authors.initials: A
authors.lastname: Von Felten
authors.forename: M
authors.initials: M
authors.lastname: Turina
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002417:Cattle; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006493:Heparin; D011475:Prosthesis Failure; D013927:Thrombosis / Q000517:prevention & control
chemical_list: D001672:Biocompatible Materials; D006493:Heparin