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

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 1 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 δ) 0.1093±0.0054, 9.8% CV; tensile strength 33.2±2.6 kPa, 24.7% CV; extension at break 103±13%, 22.6% CV; Youngʹs 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.