ObjectiveTo discuss the operation skill and clinical effects of using domestic balloon-expandable Prizvalve® transcatheter "valve-in-valve" to treat the degenerated bioprosthesis in the tricuspid position.MethodsAll the admitted surgical tricuspid valve bioprosthetic valve replacement patients were evaluated by computerized tomography angiography (CTA), ultrasound, and 3D printing technology, and 2 patients with a degenerated bioprosthesis were selected for tricuspid valve "valve-in-valve" operation. Under general anesthesia, the retro-preset Prizvalve® system was implanted into degenerated tricuspid bioprosthesis via the femoral vein approach under the guidance of transesophageal echocardiographic and fluoroscopic guidance.ResultsTranscatheter tricuspid valve implantation was successfully performed in both high-risk patients, and tricuspid regurgitation disappeared immediately. The operation time was 1.25 h and 2.43 h, respectively. There was no serious complication in both patients, and they were discharged from the hospital 7 days after the operation.ConclusionThe clinical effect of the degenerated tricuspid bioprosthetic valve implantation with domestic balloon-expandable valve via femoral vein approach "valve-in-valve" is good. Multimodality imaging and 3D printing technology can safely and effectively guide the implementation of this innovative technique.
Stent migration is one of the common complications following transcatheter valve implantation. This study aims to design a “drum-shaped” balloon-expandable aortic valve stent to address this issue and conduct a mechanical analysis. The implantation process of the stent was evaluated using a method that combines numerical simulation and in vitro experiments. Furthermore, the fatigue process of the stent under pulsatile cyclic loading was simulated, and its fatigue performance was assessed using a Goodman diagram. The process of the stent migrating toward the left ventricular side was simulated, and the force-displacement curve of the stent was extracted to evaluate its anti- migration performance. The results showed that all five stent models could be crimped into a 14F sheath and enabled uniform expansion of the native valve leaflets. The stress in each stent was below the ultimate stress, so no fatigue fracture occurred. As the cell height ratio decreased, the contact area fraction between the stent and the aortic root gradually decreased. However, the mean contact force and the maximum anti-migration force first decreased and then increased. Specifically, model S5 had the smallest contact area fraction but the largest mean contact force and maximum anti-migration force, reaching approximately 0.16 MPa and 10.73 N, respectively. The designed stent achieves a “drum-shaped” change after expansion and has good anti-migration performance.