ABSTRACT
OBJECTIVES: The aim of this study was to investigate the degree of functional improvement of a transcatheter heart valve (THV) for valve-in-valve after bioprosthetic valve fracture (BVF) of three small surgical aortic valve bioprostheses (SAVBP) using high-pressure balloon aortic valvuloplasty (HP-BAV) under standardized ex-vivo-conditions. METHODS: A THV 26 mm (Evolut R) and SAVBP 21 mm (Perimount Magna Ease, Trifecta, and Epic supra [n = 4] were used. Mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area (GOA), minimal internal diameter (MID), and pinwheeling index (PWI) were analyzed before and after HP-BAV of the SAVBP using a noncompliant balloon. Fracturing of the SAVBP was done before implantation of the THV and the balloon pressures at the point of fracture were recorded. RESULTS: The Magna Ease and Epic fractured at balloon pressures of 18 and 8 atm, respectively. The Trifecta did not fracture up to a balloon pressure of 30 atm but was dilated. HP-BAV led to increased THV expansion as evident by straightened coaptation lines of the Evolut R 26 mm with reduced PWI, increased MID, and increased GOA in all 21 mm SAVBP. Evolut R showed significantly lower MPG and higher EOA as ViV in all prostheses after HP-BAV (p < 0.001). MPG and EOA of Evolut R differed regarding the SAVBP. Evolut R presented the lowest MPG and highest EOA in Magna Ease and the highest MPG and lowest EOA in Epic supra. CONCLUSIONS: The degree of function improvement of the same THV as ViV after HP-BAV depends on the surgical valve model. Functional improvement can also be achieved without valve fracture.
Subject(s)
Aortic Valve Stenosis , Balloon Valvuloplasty , Bioprosthesis , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Humans , Transcatheter Aortic Valve Replacement/adverse effects , Transcatheter Aortic Valve Replacement/methods , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Hydrodynamics , Prosthesis Design , Treatment Outcome , Balloon Valvuloplasty/adverse effectsABSTRACT
OBJECTIVES: Transcatheter aortic valve-in-valve (ViV) procedures are increasingly performed for the treatment of degenerated surgical aortic valves with a high risk for a redo operation. For an optimal functional result, precise positioning of the transcatheter heart valve (THV) inside the SHV is crucial. The aim of this study was to systematically investigate the impact of implantation depth on the functional result after a ViV procedure in a standardized in vitro setting. METHODS: A THV 23 mm (Evolut PRO) and 3 SHV 21 mm (Perimount Magna Ease, Trifecta and Hancock II) were used for hydrodynamic testing with a constant heartbeat 64/min and a range of 55-105 ml of stroke volume in 5 different positions of the THV. The following parameters were analysed: mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area, minimal internal diameter and pin-wheeling index. RESULTS: MPG and EOA differed significantly regarding the position of the THV in the same SHV. The highest EOA and the lowest MPG were recorded for Evolut PRO with significance for both parameters in Hancock II at 4 vs 5 mm (P < 0.001), in Magna Ease at 2 mm (vs 3 mm and vs 6 mm, P < 0.001) and in Trifecta at 4 mm (vs 5 and 6 mm, P < 0.001). Leaflet coadaptation, minimal internal diameter and maximal geometric orifice area of the same TAV differ regarding the position of the TAV. CONCLUSIONS: The optimal position for hydrodynamic performance of the THV as ViV differs among specific SHV models. The findings may be useful for planning a ViV procedure using the Evolut PRO THV.
