DynaRing: A Patient-Specific Mitral Annuloplasty Ring With Selective Stiffness Segments. Journal of medical devices Frishman, S., Kight, A., Pirozzi, I., Maddineni, S., Imbrie-Moore, A. M., Karachiwalla, Z., Paulsen, M. J., Kaiser, A. D., Woo, Y. J., Cutkosky, M. R. 2022; 16 (3): 031009


Annuloplasty ring choice and design are critical to the long-term efficacy of mitral valve (MV) repair. DynaRing is a selectively compliant annuloplasty ring composed of varying stiffness elastomer segments, a shape-set nitinol core, and a cross diameter filament. The ring provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Moreover, adjusting elastomer properties provides a mechanism for effectively tuning key MV metrics to specific patients. We evaluate the ring embedded in porcine valves with an ex-vivo left heart simulator and perform a 150 million cycle fatigue test via a custom oscillatory system. We present a patient-specific design approach for determining ring parameters using a finite element model optimization and patient MRI data. Ex-vivo experiment results demonstrate that motion of DynaRing closely matches literature values for healthy annuli. Findings from the patient-specific optimization establish DynaRing's ability to adjust the anterior-posterior and intercommissural diameters and saddle height by up to 8.8%, 5.6%, 19.8%, respectively, and match a wide range of patient data.

View details for DOI 10.1115/1.4054445

View details for PubMedID 35646225