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Background: The Xeltis biorestorative transcatheter heart valve (BTHV) leaflets are made from an electrospun bioabsorbable supramolecular polycarbonate-urethane and are mounted on a self-expanding nitinol frame. The acute haemodynamic performance of this BTHV was favourable., Aims: We sought to demonstrate the preclinical feasibility of a novel BTHV by evaluating the haemodynamic performances of five pilot valve designs up to 12 months in a chronic ovine model., Methods: Five design iterations (A, B, B', C, and D) of the BTHV were transapically implanted in 46 sheep; chronic data were available in 39 animals. Assessments were performed at implantation, 3, 6, and 12 months including quantitative aortography, echocardiography, and histology., Results: At 12 months, greater than or equal to moderate AR on echocardiography was seen in 0%, 100%, 33.3%, 100%, and 0% in the iterations A, B, B', C, and D, respectively. Furthermore, transprosthetic mean gradients on echocardiography were 10.0±2.8 mmHg, 19.0±1.0 mmHg, 8.0±1.7 mmHg, 26.8±2.4 mmHg, and 11.2±4.1 mmHg, and effective orifice area was 0.7±0.3 cm2, 1.1±0.3 cm2, 1.5±1.0 cm2, 1.5±0.6 cm2, and 1.0±0.4 cm2 in the iterations A, B, B', C, and D, respectively. On pathological evaluation, the iteration D demonstrated generally intact leaflets and advanced tissue coverage, while different degrees of structural deterioration were observed in the other design iterations., Conclusions: Several leaflet material iterations were compared for the potential to demonstrate endogenous tissue restoration in an aortic valve in vivo. The most promising iteration showed intact leaflets and acceptable haemodynamic performance at 12 months, illustrating the potential of the BTHV.

Objectives: To evaluate the in vivo feasibility of aortography with one accurately timed diastolic low-volume contrast injection for quantitative assessment of aortic regurgitation (AR) post transcatheter aortic valve replacement (TAVR)., Background: With the rise of a minimalistic approach for TAVR, aortography (re)emerges as a pragmatic tool for AR assessment. In a mock circulation system, we have validated the accuracy of a single diastolic injection triggered by electrocardiogram (ECG) with low-contrast volume., Methods: Two-phase experiment: first, a series of aortograms were performed in a porcine model, with 8 mL of contrast using the synchronized (SYNC) and the conventional non-synchronized (NS) injections. In a second phase, we developed a model of AR by inserting partially unsheathed Wallstents of 6-10 mm of diameter across the pig's aortic valve, performing SYNC injections with 8 mL of contrast and NS injections with 8 mL and 15 mL (rate: 20 mL/sec). Respective accuracies of SYNC vs. NS were assessed using Passing-Bablock regression. An angiography core laboratory performed quantitative AR assessment with videodensitometry (VD-AR)., Results: The SYNC injections produced higher opacification of the aortic root compared with NS injections (P = 0.04 for density). In the second phase, a regression line for predicting VD-AR based on the SYNC injection resulted in a lower intercept and a slope closer to the line of identity (y = 11.9 + 0.79x, P < 0.001, r 2  = 0.94) with the NS-8 mL than with the NS-15 mL injection (y = 26.5 + 0.55x, P < 0.001, r 2  = 0.81)., Conclusion: Synchronized diastolic injection with low contrast volume produced denser images in the aortic root and more accurate than the conventional injection; thus, may be an appealing alternative for assessment of AR post TAVR., (© 2018 Wiley Periodicals, Inc.)