Testing of a novel percutaneous temporary aortic valve in a rabbit model of acute severe aortic regurgitation: an experimental study

Purpose: Device management of hemodynamic instability due to acute aortic regurgitation is not available. A novel, catheter-based, temporary aortic valve (TAV) has been in development. Early prototypes (balloon-based TAV) have undergone proof-of-concept studies in mathematical, bench and animal models. The redesigned membrane-based TAV prototype is evaluated in a rabbit model of acute severe aortic regurgitation. Methods: Acute aortic regurgitation was simulated by deploying a self-expanding endovascular stent across the aortic annulus. Eight rabbits of body weights ranging 4.9-5.4 kg were randomly assigned to two groups: those received additional hemodynamic support with the TAV prototype immediately after aortic regurgitation was induced versus no TAV support. The survival times of the two groups were compared. Results: Comparing the groups with TAV versus without TAV, the mean body weights were similar: 4.99 +/- 0.06 vs. 5.10 +/- 0.22 kg (p = 0.71). The mean stent sizes used to create acute aortic regurgitation were similar: 6.25 +/- 0.50 vs. 6.75 +/- 0.50 mm, respectively (p = 0.53). The mean survival times also did not differ significantly: 21.00 +/- 15.41 vs. 8.25 +/- 2.75 minutes, respectively (p = 0.45). A slight trend appeared to be in favor of longer survival in the TAV supported group. Conclusions: In a rabbit model of acute massive aortic regurgitation, the use of the TAV support prototype did not hasten the animals' death, but rather survival may be enhanced by the use of the device. Future studies specifically designed to evaluate the efficacy of the TAV catheter can be valuable in this new technology.