In vitro results of a new minimally invasive aortic valve resecting tool

Background: Aortic valve replacement (AVR) using extracorporeal circulation is currently the treatment of choice for symptomatic aortic stenosis. However, patients with multiple high-risk comorbid conditions may benefit from reduced ECC time by a simplified and faster resection in conjunction with quick sutureless valve implantation. Methods: A prototype of a new minimally invasive aortic valve resection tool equipped with rotating and foldable Nitinol cutting edges was designed. Commercially available aortic valve bioprostheses were artificially calcified (group 1: moderate calcified, n = 8, group 2: severely calcified, n = 8). In vitro resection was performed using a 21 mm cutting blade. Resection time (RT), maximum turning moment (MTM) and number of required rotations (NR) were measured. Furthermore, particle generation during the process of cutting was obtained and quantified. Results: Aortic valve cutting could be obtained without any complications in all cases. Cutting process resulted in a RT of 15.5 ± 3 s in group 1 compared to 34.9 ± 15 s in group 2 (p = 0.005), MTM was 3 ± 0.6 N m in group 1 compared to 3.5 ± 0.6 N m in group 2 (p = 0.068) and NR were 30.6 ± 2.3 in group 1 compared to 48.1 ± 15.5 in group 2 (p = 0.007). Particle generation was 1.77 ± 0.17 g in group 1 compared to 1.41 ± 0.44 g in group 2 (p = 0.047). Conclusions: These first in vitro results confirm feasibility and accelerated aortic valve resection within 30 s. This new concept holds promise for very fast AVR in combination with insertion of sutureless aortic valve prosthesis, targeting for ischemic times less than 10 min in the open heart situation. Finally, resection and percutaneous AVR within 1 min in the beating heart situation is envisioned.