Hemodynamic characterization of calcified stenotic human aortic valves before and after treatment with a novel aortic valve repair system.

BACKGROUND AND AIM OF THE STUDY: The repair of calcified stenotic aortic valves may be a viable alternative to current valve treatments for early-stage aortic valve disease. To date, evaluation of valve repair feasibility on the benchtop has not been performed. A pulsatile flow system for testing intact human aortic valves was developed to perform quantitative hemodynamic and mechanical assessment of a new aortic valve repair approach.

METHODS: Intact calcified human aortic valves were divided into two groups with effective orifice area (EOA) > or =2.0 cm2 (group I, n = 6) or <2.0 cm2 (group II, n = 6). All valves were chemically debrided in stages for up to 60 min. A subset of valves in each group was also surgically debrided. At each stage, pre- and post-treatment hemodynamic assessment and video motion analysis were performed in the pulsatile flow system at multiple levels of physiological loading. Mineral removed was quantified using atomic absorption spectroscopy.

RESULTS: Progressive removal of mineral with both mechanical and chemical debridement was associated with improved hemodynamic function of calcified human aortic valves. Improvements in EOA of up to 40% and decreases in transvalvular pressure gradient (deltaP) of up to 46% were seen. No clinically relevant increases in regurgitation were observed.

CONCLUSION: Repair of stenotic calcified aortic valves using surgical and chemical debridement showed that removal of calcific deposits was directly associated with improvements in valve hemodynamic function. The level of improvement was proportional to the degree of aortic valve stenosis, to the use of surgical debridement, and to the duration of chemical debridement treatment. The study results suggested that aortic valve repair warrants further investigation as an alternative to current valve treatments in patients with early to mid-stage calcific aortic valve disease.