Related Experiment Video
Updated: Jun 19, 2026

Transcatheter Pulmonary Valve Replacement from Autologous Pericardium with a Self-Expandable Nitinol Stent in an Adult Sheep Model
Published on: June 8, 2022
Current balloon-expandable transcatheter heart valve and delivery systems
Fabian Nietlispach1, Namal Wijesinghe, David Wood
1Department of Cardiology, St. Paul's Hospital, British Columbia, Canada.
Objectives:
Transcatheter valve and valve delivery systems are undergoing rapid evolution. We describe the current generation balloon-expandable valve and delivery systems.
Background And Methods:
The SAPIEN XT valve represents the newest generation balloon-expandable aortic bioprosthesis. A cobalt-chromium alloy frame and additional design modifications facilitate a reduction in delivery profile while maintaining structural integrity, hemodynamics, and durability. The RetroFlex 3 delivery system represents the latest clinically available delivery system. It incorporates a fixed, tapered, and deflecting crossing tip to facilitate atraumatic introduction and a rapid inflation lumen to reduce valve motion during deployment. The NovaFlex delivery system represents the next generation delivery catheter. When used in conjunction with the SAPIEN XT valve and a specially constructed introducer sheath the inner and the outer diameters are 18 and 21 F, respectively.
Results:
The RetroFlex 3 delivery system was utilized in nine patients and the NovaFlex delivery system in four. The valve implanted was the SAPIEN in six and the SAPIEN XT valve in seven. Implantation was successful in all patients. A reduction in device movement during balloon deployment was apparent as compared with earlier delivery systems. Aortic mean gradient fell from 45.6 (+/-15.1) mm Hg to 13.2 (+/-5.1) mm Hg, valve area rose from 0.68 (+/-0.19) to 1.5 (+/-0.28) cm(2). No patient had more than mild paravalvular regurgitation.
Conclusion:
Transcatheter valves and delivery systems continue to improve in terms of profile and ease of use.
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