Abstract
PurposeThe paper present findings from an in vitro experimental study of a stentless human aortic bioprosthesis (HAB) made of bacterial cellulose (BC). Three variants of the basic model were designed and tested to identify the valve prosthesis with the best performance parameters. The modified models were made of BC, and the basic model of pericardium.MethodsEach model (named V1, V2 and V3) was implanted into a 90 mm porcine aorta. Effective Orifice Area (EOA), rapid valve opening time (RVOT) and rapid valve closing time (RVCT) were determined. The flow resistance of each bioprosthesis model during the simulated heart systole, i.e. for the mean differential pressure (ΔP) at the time of full valve opening was measured. All experimental specimens were exposed to a mean blood pressure (MBP) of 90.5 ± 2.3 mmHg.ResultsThe V3 model demonstrated the best performance. The index defining the maximum opening of the bioprosthesis during systole for models V1, V2 and V3 was 2.67 ± 0.59, 2.04 ± 0.23 and 2.85 ± 0.59 cm2, respectively. The mean flow rate through the V3 valve was 5.7 ± 1, 6.9 ± 0.7 and 8.9 ± 1.4 l/min for stroke volume (SV) of 65, 90 and 110 mL, respectively. The phase of immediate opening and closure for models V1, V2 and V3 was 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.ConclusionsThe V3 model of the aortic valve prosthesis is the most effective. In vivo tests using BC as a structural material for this model are recommended. The response time of the V3 model to changed work conditions is comparable to that of a healthy human heart. The model functions as an aortic valve prosthesis in in vitro conditions.
Highlights
The rate of aortic valve replacement (AVR) surgeries is growing each year
This paper presents the results of an in vitro study of an human aortic bioprosthesis (HAB) aortic valve prosthesis made of bacterial cellulose (BC)
The parameters of the prosthesis orifice area indicated the lowest performance for the V2 model, for which the Effective Orifice Area (EOA) was more than 25% smaller than the EOA for the V3 model (Table 2)
Summary
The rate of aortic valve replacement (AVR) surgeries is growing each year. In the United States between 1999 and 2011 this rate increased on average by 1.6%, and the number of surgical AVRs for elderly patients was on the rise. during this 13-year-long observation, the number of mechanical prosthetic implants decreased in the US by 28.6% in favour of bioprosthesis implants, and currently 80% of valve prosthesis implants worldwide are tissue valves.5Bioprostheses are very prone to structural degeneration, and for this reason are recommended to elderly patients, while younger patients need reoperation after some time. In the United States between 1999 and 2011 this rate increased on average by 1.6%, and the number of surgical AVRs for elderly patients was on the rise.. In the United States between 1999 and 2011 this rate increased on average by 1.6%, and the number of surgical AVRs for elderly patients was on the rise.37 During this 13-year-long observation, the number of mechanical prosthetic implants decreased in the US by 28.6% in favour of bioprosthesis implants, and currently 80% of valve prosthesis implants worldwide are tissue valves.. Bioprostheses are very prone to structural degeneration, and for this reason are recommended to elderly patients, while younger patients need reoperation after some time. In bovine pericardial valves degeneration occurs 4 years later, but this is still not a sufficiently long reoperation-free period for younger patients. That is why many scientists are working on a substitute for a heart valve that would eliminate the need for reoperation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
