Reproducibility of the mechanical properties of Vivostat system patient-derived fibrin sealant.

Abstract

Conventional "autologous" fibrin sealants, prepared from fibrinogen concentrates are inconsistent in their physical properties; this reflects the wide variation in the fibrinogen level of the single donor plasma from which they are made. In contrast, the Vivostat System produces a fibrin sealant of reproducible concentration and mechanical properties that are independent of the source plasma fibrinogen concentration. Fibrin solution concentrations prepared with the Vivostat System were 22.0 +/- 0.7 mg/ml (95% CI) with a coefficient of variation [CV] of 10.6% from samples of source plasma with a range of fibrinogen concentration between I and 6 mg/ml (mean 3.28 +/- 0.38 mg/ml (95% CI), 37% CV). Values of viscoelastic and tensile parameters after 11 min and 1 h, respectively, were: storage modulus (G') 891.5 +/- 72.9 Pa, 16.2% CV; loss modulus (G") 98.7 +/- 9.8 Pa, 23.2% CV; loss tangent (tan delta) 0.1093 +/- 0.0054, 9.8% CV; tensile strength 33.2 +/- 2.6kPa, 24.7% CV; extension at break 103 +/- 13%, 22.6% CV; Young's modulus 12.0 +/- 1.0 kPa, 16.6% CV. In the clinical setting this reproducibility provides the surgeon with a patient-derived fibrin sealant that can be expected to perform similarly from patient to patient.