gms | German Medical Science

Background: TAVI as Valve in Valve (ViV) is increasingly used in the mitral position. However, aside from some case reports TAVI has not been systematically evaluated for degenerated mitral valves after mitral valve repair with an annuloplasty ring. Semi-rigid rings may serve as a more appropriate scaffold for proper anchoring of a TAVI as they may change from their oval to a round shape thereby fitting to the implanted TAVI.

Methods: 5 rigid and semi-rigid rings of 4 manufacturers (Edwards Physio I and II (EPI, EPII), Sorin 3D Memo (S3D), Medtronic Simulus (MS), SJM Saddle and SJM Sequin with sizes 28mm-36mm and Edwards Sapien III TAVI 23mm, 26mm, 29mm were used. Pre-evaluation comprised insertion/inflation of the TAVI in the ring and visual inspection for paravalvular leackage 4mm² (pvl). Only valves not showing pvl were then submitted to hemodynamic evaluation with a pulse duplicator. Cusp movement was assessed with a high-speed-camera. Mean transvalvular gradients (TVG) were measured.

Results: SJM saddle valves of all sizes and SJM Sequin valves 32 and 34 showed marked pvl combined with all TAVI sizes thus not undergoing hemodynamic testing. It was further shown that ring sizes > 36mm did not allow for a proper fit of even the largest TAVI in the ring of all manufacturers and were consequently not hemodynamically evaluated. The 23mm TAVI was too small for any ring size. The lowest gradients were achieved with the 26mm TAVI in 30mm and 32mm and the 29mm TAVI in 32mm and 34mm rings. However, the latter could only be demonstrated with the Medtronic as well as the Sorin rings.

Conclusion: Not all currently available annuloplasty rings are ideal scaffolds for TAVI placement. It appears that a more proper fit can be achieved with semi-rigid rings than with rigid ones. 23mm TAVI appeared to be too small for an adequate anchoring in even the smallest available ring. Thus, 26mm as well as 29mm TAVI fit properly in ring sizes between 28mm and 34mm. Surgeons may be well advised to choose from those ring brands and sizes which allow for good placement of a TAVI in view of possible valve degeneration in the later course.