Background
To date, no studies provide detailed analysis of vascular impedance changes after total aortic arch replacement. We investigated ventriculoarterial coupling (VAC) and vascular impedance after replacement of the aortic arch with conventional prostheses vs. decellularized allografts.

Material and Methods
After preparing decellularized aortic arch allografts, their mechanical, histological and biochemical properties were evaluated and compared to native aortic arches and prostheses in vitro. Total aortic arch replacement was performed in dogs with prostheses or decellularized allografts (n=5/group). Aortic flow and pressure were recorded continuously, left ventricular pressure-volume relations were measured by using a pressure-conductance catheter. From the hemodynamic variables end-systolic elastance (Ees), arterial elastance (Ea) and VAC were calculated. Characteristic impedance (Z) was assessed by Fourier analysis.

Result
While Ees did not differ between the groups and over time, Ea showed a higher increase in the prosthesis group (4.01+/-0.67 vs. 6.18+/-0.20mmHg/ml) in comparison to decellularized allografts (5.03+/-0.35 vs. 5.99+/-1.09mmHg/ml). This led to impaired VAC in the prosthesis group, while it remained unchanged in the allograft group (62.5 vs. 3.9%). Z showed a strong increasing tendency in the prosthesis group and it was markedly higher after replacement when compared to decellularized allografts (44.6+/-8.3dyn•sec•cm-5 vs. 32.4+/-2.0dyn•sec•cm-5).

Conclusion
Total aortic arch replacement with prostheses leads to contractility-afterload mismatch by means of increased impedance and invert VAC. Implantation of decellularized allografts preserves vascular impedance thereby improving ventriculoarterial mechanoenergetics after aortic arch replacement.