# Biomechanical Optimization of Mitral Valve Repair Operations and Annuloplasty Rings for Primary Mitral Valve Regurgitation

> **NIH NIH F32** · STANFORD UNIVERSITY · 2022 · $73,942

## Abstract

PROJECT SUMMARY
Mitral valve regurgitation is one of the most prevalent valvular heart diseases worldwide and is a significant
cause of global morbidity and mortality. Although mitral repair operations were first described several decades
ago, numerous new repair techniques have been developed in recent years. However, these techniques were
described primarily based on anatomic principles and guided by valvular appearance and function, mostly via
visual assessment and echocardiography. The biomechanical engineering principles and fundamentals
underlying various mitral valve repair techniques have rarely been investigated, and repair strategy remains
largely based on surgeon’s preference. With evolving guidelines advocating earlier, more aggressive intervention
with mitral valve repair whenever possible, especially for regurgitant lesions, the goal of this proposal is to
establish a solid understanding of mitral valve repair biomechanics for primary mitral regurgitation. This is
essential for optimizing these complex mitral valve repair operations to enhance valve repairability, expand valve
repair technique adoptability, and improve repair durability. Aim 1 will characterize and optimize our novel 3D-
printed mitral annuloplasty ring prototype with selective flexibility. Using healthy human cardiac MRI marker
tracking and fatigue testing results, the annuloplasty ring design will be perfected to facilitate the native mitral
annular motion and enhance durability. Next, primary mitral regurgitation models with leaflet prolapse and
annular dilation will be created and assessed. Current clinically employed repair operations, namely triangular
resection, neochordal reconstruction, and ring annuloplasty using our novel design and other annuloplasty rings
with varying flexibility, will be tested on these primary mitral regurgitation models. Innovative biomechanical
sensors and advanced cardiac imaging technologies will facilitate the detailed analysis of the engineering
principles underlying these operations and annuloplasty ring designs. Aim 2 will validate findings from the ex
vivo experiments in pre-clinical ovine models. The effect of annuloplasty rings’ flexibility on natural mitral annular
motion and left ventricular vortex flow pattern after ring annuloplasty will be investigated in healthy ovine models
without mitral regurgitation. The mitral valve repair operations will be evaluated on the ovine models with chronic
primary mitral regurgitation generated by posterior leaflet chordal transection. The results will be compared to
the ex vivo studies. The experiments proposed herein have great clinical applicability. Findings from this study
can help surgeons gain substantial understanding of mitral valve repair biomechanics thereby translating directly
to patient care in the operating room.

## Key facts

- **NIH application ID:** 10597517
- **Project number:** 5F32HL158151-02
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Yuanjia Zhu
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $73,942
- **Award type:** 5
- **Project period:** 2021-07-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10597517

## Citation

> US National Institutes of Health, RePORTER application 10597517, Biomechanical Optimization of Mitral Valve Repair Operations and Annuloplasty Rings for Primary Mitral Valve Regurgitation (5F32HL158151-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10597517. Licensed CC0.

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