In Vitro Study of a Stentless Aortic Bioprosthesis Made of Bacterial Cellulose

Abstract

Purpose—The paper present findings from anin vitroexper-imental study of a stentless human aortic bioprosthesis(HAB) made of bacterial cellulose (BC). Three variants of thebasic model were designed and tested to identify the valveprosthesis with the best performance parameters. The mod-ified models were made of BC, and the basic model ofpericardium.Methods—Each model (namedV1,V2andV3) was implantedinto a 90 mm porcine aorta. Effective Orifice Area (EOA),rapid valve opening time (RVOT) and rapid valve closingtime (RVCT) were determined. The flow resistance of eachbioprosthesis model during the simulated heart systole, i.e.for the mean differential pressure (DP) at the time of fullvalve opening was measured. All experimental specimenswere exposed to a mean blood pressure (MBP) of 90.5±2.3mmHg.Results—TheV3model demonstrated the best performance.The index defining the maximum opening of the bioprosthe-sis during systole for modelsV1,V2andV3was 2.67±0.59,2.04±0.23 and 2.85±0.59 cm2, respectively. The meanflow rate through theV3valve was 5.7±1, 6.9±0.7 and8.9±1.4 l/min for stroke volume (SV) of 65, 90 and 110 mL,respectively. The phase of immediate opening and closure formodelsV1,V2andV3was 8, 7 and 5% of the cycle duration,respectively. The mean flow resistance of the models was:4.07±2.1, 4.28±2.51 and 5.6±2.32 mmHg.Conclusions—TheV3model of the aortic valve prosthesis isthe most effective.In vivotests using BC as a structuralmaterial for this model are recommended. The response timeof theV3model to changed work conditions is comparable tothat of a healthy human heart. The model functions as anaortic valve prosthesis inin vitroconditions.